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Outlook for Energy Storage Technology: A Basic Materials Perspective
Brennan King, Zhengye (Lumin) Chen, Miles Bloomenkranz, Daniel Estevez, Surya Giri
*** Energy & Energy Policy
Stephen Berry & George Tolley The University of Chicago
December 4, 2015
Abstract This paper examines the battery technologies most relevant to solving current energy
storage problems worldwide from a basic materials perspective. Though it is clear that
current lithium-ion technologies will be dominant in the foreseeable future, novel
energy storage technologies are emerging rapidly and it is important researchers are
able to focus their efforts on technologies most likely to see successful wide-scale
adoption. To aid in this decision making process, we analyzed the price behavior,
supplier concentration, and economic resilience of basic material markets associated
with several promising battery technologies which we think will play an important role
in solving economic, financial, and political issues related to energy and energy storage.
Our findings indicate that in the face of an increasingly competitive lithium market,
technologies associated with more abundant materials such as sodium may have
significant advantages.
We would like to acknowledge Professors Berry and Tolley as well as Jing Wu and Jaeyoon Lee for their guidance and instruction throughout the Autumn 2015 quarter. Additionally we would like to thank Dr. Samanvaya Srivastava for being kind enough to interview with us and provide additional information on flow battery technologies.
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Table of Contents
Table of Contents I. Introduction II. Objective III. Overview of Energy Storage Technologies
Consumer Electronics Automotive Grid Scale Storage
IV. Analysis of Materials Markets Metrics and Methodologies: Assumptions: Materials Analysis
Lithium: Graphite: Sodium: Vanadium: Bromine:
V. Consequences for Storage Technology Consumer Electronics: Automotive: Grid Storage Further Inquiry:
VI. Appendix
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I. Introduction
The need for a revolution in battery technology is one of the most significant
technological hurdles facing the world today. Demand for new and innovative energy
storage technologies lies at the heart of many of the core energy-related issues. Issues
which are hindering significant advancements in industries including consumer
electronics, transportation, and grid energy supply. Advancements in transportation and
grid energy storage are particularly important; in America alone, transportation and the
electricity grid account for two-thirds of all energy use . George Crabtree, the head of the 1
Joint Center for Energy Storage Research (JCESR) and a leading energy storage expert,
noted in his 2014 JCESR report that these sectors are in need of a transformation which
must be driven by high performance, low cost energy storage; namely batteries. The
current target benchmark for an ideal battery technology, as set by the U.S. Department
of Energy in 2012, is five times greater than current performance at one-fifth the cost . 2
This extremely ambitious, yet necessary, goal translates to a mark of 400 watt-hours per
kilogram by 2017 . 3
One area in which such advancements in battery technology stand to make an
enormous impact is transportation. Innovations in transportation technology with
growing research and development in hybrid electric vehicles (HEVs) has the potential
1 Administration, Energy Information. "Monthly Energy Review, November 1995." 1995. doi:10.2172/150918. 2 The joint center for energy storage research: A new paradigm for battery research and development Crabtree, George, AIP Conference Proceedings, 1652, 112128 (2015), DOI:http://dx.doi.org/10.1063/1.4916174 3 Noorden, Richard Van. "The Rechargeable Revolution: A Better Battery." Nature.com. March 05, 2014. Accessed December 2015. http://www.nature.com/news/therechargeablerevolutionabetterbattery1.14815.
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to lower the economic strain gasoline puts on many consumers. It also address serious
environmental, humanitarian and political concerns by both reducing our greenhouse
gas emissions as well as our dependency on foreign oil. Lithium-ion batteries stand as
the current dominant technology in the space, but are failing to keep pace with demand
for capacity. While lithium-ion technology has been progressing rapidly for many years,
researchers expect that advancements in the energy density of lithium-ion batteries will
soon cap out at a projected ceiling of 30% more energy by weight than current models . 4
Two related key areas in which improvements in battery technology could drive
significant advancement are the renewable energy and grid storage spaces. While wind
and solar powered energy are becoming more popular, a major bottleneck preventing
more serious adoption of the technologies is a lack of grid level energy storage. For
example, a large portion of wind energy is wasted during nighttime hours when wind
might be at its peak because energy demand is at a minimum and there is no way to
capture and store the generated energy for later consumption. China, which has the
largest installed capacity of wind farms in the world, provides a striking example of this.
A report by the China Renewable Energy Society revealed that ten billion kilowatt hours
of power were wasted in 2011 due to insufficient grid storage, costing $793 million in
forgone revenue . In the U.S. as well, much of the 40,000MW wind turbine capacity in 5
2010 was wasted due to the fact that generation outpaced the grid’s distribution capacity
4 to 1 . 6
4 Ibid. 5 Blackman, Sarah. "Wasted Wind Energy: Solving the Problem of Bad Grid Connections." Power Technology. June 28, 2012. Accessed December 2015. http://www.powertechnology.com/features/featurewastedwindenergygridconnectionsturbines/. 6 Ibid.
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Currently the United States only has about 24.6GW of grid storage capacity,
about 2.3% of its total electric production capacity as estimated by the U.S. Department
of Energy . Of this storage capacity, the vast majority is unuseable for energy storage 7
applications outside of hydroelectric as it relies on pumped hydro storage technology
which is limited geographically in the same manner as hydroelectric generation . 8
Developing large-scale efficient storage devices would address this bottleneck that
currently hinders efficient use of renewable technologies by overcoming the temporal
constraint on energy supply and demand. In addition to complementing renewable
energy sources, low-cost and low-transfer loss storage technology would increase grid
efficiency by significantly smoothing peaks in energy demand. Smoothing peaks would
decrease the need for reserve plants, sites used only to meet excess demand, which are
often the least efficient and significant contributors to emissions . A study by the 9
Electric Power Research Institute suggests that such advancements, coupled with
intelligent resource management “smart grid” technologies, could reduce energy use 4%
by 2030, the equivalent of eliminating the emissions of about 50 million cars . 10
Additionally, this would translate to savings in excess of $20 billion annually for utility
customers worldwide . 11
7 U.S Department of Energy. "Grid Energy Storage." Smart Grid Technology and Applications, December 2013, 4. Accessed December 2015. doi:10.1002/9781119968696.ch12. 8 Ibid. 9 George Crabtree, Elizabeth Kocs, Thomas Aláan, Energy, society and science: The fiftyyear scenario, Futures, Volume 58, April 2014, Pages 5365, ISSN 00163287, http://dx.doi.org/10.1016/j.futures.2014.01.003. 10 “Grid Energy Storage.” 11 Ibid.
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II. Objective
Clearly then much stands to be gained from the advancement of energy storage
technologies at all levels, whether it is as small as increasing the life of our cell phones or
as transformative as introducing novel grid scale batteries that change the very way our
entire utility industry operates. While battery technology has been around for hundreds
of years, striking innovation will be needed in the modern era to drive transformation
and help energy storage technology reach its full potential. Researchers around the
world recognize the importance of this task and are constantly testing novel concepts
and potential designs. These innovations have produced such a wide range of potential
battery technologies that identifying the most promising technologies in which to invest
further time and research has become a significant challenge.
There are many metrics that can be used to aid in this decision. While pure
performance metrics such as energy density and voltage efficiency provide good
indicators as to which battery technologies might be promising, what will ultimately be
necessary to drive successful adoption of a given technology is its commercial feasibility.
A useful way to analyze the commercial feasibility of a given battery technology is by
determining its levelized cost of electricity (LCOE). LCOE answers the question, “If I put
a kWh into the battery and pull it out, how much will the power I get out cost me on
average over the lifetime of the battery?” If power from a battery is more expensive than
power from the grid it doesn’t make sense to draw power from the battery. The average
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costs for wholesale and retail grid electricity during peak times are $.06-.07 / kWh and
$.12 / kWh on average respectively . 12
These peak prices then, are the minimum prices that a battery technology must
beat in order to be considered commercially feasible. Depending on what sort of cycles
you assume current battery technologies don’t come close to this. For example, a $300 /
kWh battery with 1000 cycles and 90% efficiency costs you $.33 / kWh. As we are still
many years away from batteries being able to outperform grid prices at all times, the
current aim is to simply beat peak prices of electricity. Grid systems often employ a
pricing system that takes into account time of use. It costs more money for the grid to be
able to produce electricity at peak times, because there is a need for additional “peaker”
power stations to be operated. However, the LCOE of a battery is flat because energy 13
can be produced at one price and then stored indefinitely until it is needed to be used.
This means that battery technologies which beat peak prices create opportunities for
energy arbitrage. For example, if the average LCOE of electricity on the grid was $.12 /
kWh but $.24 / kWh at its peak, and the LCOE of a battery was $.20 /kWh, then an
arbitrage opportunity would exist. At any time when the grid price was between $.20 /
kWh and $.24 /kWh, it would make sense to use energy stored in batteries instead of
paying extra to operate expensive peaker power plants.
While levelized cost is useful it is difficult to calculate without access to the
battery technology itself, particularly for those technologies that are currently being
researched and do not yet exist. One major input in the levelized cost of a battery,
12 Naam, Ramez. "Why Energy Storage Is About to Get Big – and Cheap." Ramez Naam. April 14, 2015. Accessed December 2015. http://rameznaam.com/2015/04/14/energystorageabouttogetbigandcheap/. 13 Ibid.
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however, is the price of its material components. From this we can learn something
about the commercial feasibility of proposed technologies by examining their proposed
component materials. In this paper we seek to contribute to the decision making process
of energy storage researchers by assessing the commercial viability of battery
technologies through the analysis of basic material markets.
We proceed by first surveying the current and future battery technologies in the
consumer electronic, automotive, and grid-scale spaces in order to determine the
materials most associated with potential future designs. We then analyze each material’s
marketplace in order to characterize its potential price behavior as the result of price
volatility, potential for market power concentration, historical economic resilience, and
correlation with complementary materials. We characterize these by calculating
annualized volatility, Herfindahl-Hirschman indices, beta, and correlation, the
methodologies of which are discussed at the beginning of the materials analysis. Lastly
we conclude by analyzing the pros and cons of the previously discussed potential
technologies in the consumer electronic, automotive, and grid scale spaces given our
analysis of basic material markets.
III. Overview of Energy Storage Technologies
To begin our survey of battery technologies, it seems pertinent to first discuss
batteries at their most general level. Batteries are devices which convert chemical
potential energy into electrical energy. They are made of three functional parts; the
anode (the positive electrode), the cathode (the negative electrode), and an electrolyte.
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The electrolyte is a liquid with charged particles called ions which facilitates a chemical
reaction with the electrodes. This reaction causes electrons to build up at the anode,
creating a difference in electrical potential. When the circuit is closed, the electrons
become free to pass through the wire toward the cathode and provide electricity to
whatever components are integrated with the circuit . 14
There are three basic units of measurement when talking about batteries;
Voltage, current, and resistance. A tank of water and a hose provide a good analogy for
this. Voltage can be thought of as the amount of pressure pushing the water through the
hose. Current is like the flow rate of water out of the hose. And lastly, resistance is the
diameter of the hose. These three values are related by Ohm’s law which states that the
current is equal to the voltage divided by the resistance. Returning to the analogy, the
flow rate of water out of the hose is determined by the pressure in the tank divided by
the resistance of the opening. In this paper we also discuss an important metric called
“energy density”. This measurement represents the amount of energy stored in a specific
system per unit volume or mass. Essentially, this represents the amount of actually
energy a certain type of battery or material can contain within a standardized amount . 15
Consumer Electronics
One enormous space in which energy storage plays a key role is the consumer
electronics industry. We use a multitude of devices on a daily basis, most of which rely
14 Battery Stuff. "Battery Basics: A Layman's Guide to Batteries." Battery Basics: A Layman's Guide to Batte. Accessed December 2015. http://www.batterystuff.com/kb/articles/batteryarticles/batterybasics.html. 15 Thompson, A., and B. N. Taylor. "NIST Guide to the SI." National Institute of Standards and Technology. 2015. Accessed December 04, 2015. http://physics.nist.gov/Pubs/SP811/sec04.html.
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on battery technology as a fundamental component to their functionality. Demand for
energy storage technology in this space is only set to increase, global consumer
electronics revenues have risen to $1.77 trillion in 2015 and are expected to rise to $2.89
trillion by 2020 over an expected 815.4 million users. 16
Smartphones are massive drivers of this demand. Between Spring 2008 to 2015,
U.S smartphone (Blackberry, iPhone, Android) ownership has grown immensely, from
20.38 million to 174.62 million owners, with a further 17.27 million planning to
purchase a smartphone (who may or may not be current owners) in the next 12 months.
Desktop and laptop computer demand have grown at slower rates between Spring 2008
and 2015, with 227.2 million reporting ownership and 20.14 million slated to purchase a
computer within the next 12
months. With global user
penetration for these devices
expected to reach 20.3% by 2020,
it’s clear that future battery
technologies pertaining to these
devices will be critical to energy
storage in the consumer
electronics space. 17
16 IHS. Consumer electronics revenue worldwide from 2008 to 2013 (in billion U.S. dollars). http://www.statista.com.proxy.uchicago.edu/statistics/273150/consumerelectronicsrevenueworldwidesince2008. 17 "Consumer Electronics Worldwide." Statista. Accessed December 2015. http://www.statista.com.proxy.uchicago.edu/outlook/251/100/consumerelectronics/worldwide#.
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Current Consumer Electronics Technology:
Currently the consumer electronic storage space is dominated by lithium-ion
batteries. We will discuss lithium-ion more extensively in our section on automotive
energy storage technology, but essentially it is a very efficient and energy dense battery
technology in which lithium ions are used to transfer charge from the negative electrode
to the positive electrode. The technology has seen drastic improvement over the last
several decades, modern lithium-ion batteries now have over twice the energy density as
the first commercial ‘Goodenough’ cathode-carbon anode versions sold by Sony in 1991
and are ten times times cheaper. However, while manufacturers have significantly 18 19
optimized materials and supply-chains to reduce price, it is becoming increasingly
difficult to cope with consumer electronics’ trend towards smart, wearable, and
multifunctional technologies -- all developments that prove to require greater and
greater amounts of energy per use. The capabilities of lithium-ion technology are 20
reaching a limit and it is expected to plateau at most with 30% more energy-density in
the near future. It additionally faces three key drawbacks in consumer electronics use:
firstly, li-ion batteries cannot be charged quickly, secondly, li-ion batteries’ memory
effect dictates that performance falls after 1,000 charge cycles, and lastly, li-ion batteries
are difficult to recycle.
18 LeVine, Steve. "Not Good Enough for Goodenough." Quartz. February 05, 2015. Accessed December 04, 2015. http://qz.com/338767/themanwhobroughtusthelithiumionbatteryat57hasanideaforanewoneat92/. 19 Naam, Ramez. "Energy Storage Gets Exponentially Cheaper Too." Ramez Naam. September 25, 2013. Accessed December 2015. http://rameznaam.com/2013/09/25/energystoragegetsexponentiallycheapertoo/. 20 Crabtree, George. “The Joint Center for Energy Storage Research: A New Paradigm for Battery Research and Development.” Joint Center for Energy Storage Research (2014): Accessed December, 2015.
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Future Consumer Electronics Technology:
Clearly then new technologies will be needed to advance the consumer electronics
storage space, for the foreseeable future however lithium-ion will play the dominate
role. Even so, numerous academic and consumer electronics firms’ research teams have
been developing improvements to current lithium-ion technology. These include the use
of silicon nanowire lithium-ion batteries, MIT’s development of “simple and scalable”
‘yolk-and-shell’ nanoparticles that increase lithium-ion lifecycles, and the
commercialization of flexible batteries by LG Chem and Samsung that can be bent for
wearable devices. Research into thin-film technology that enables printing of a battery
onto multiple surfaces, the substitution of solid-state electrolytes for liquid-state
electrolytes that can circumvent the danger of battery explosions , and increasing 21
commercial pressures on hardware manufacturers to shift towards more efficient
production processes to create more power-efficient components -- all are factors that
are augmenting current lithium-ion technology.
While lithium-ion batteries will likely be used for the near future, there are many
researchers exploring non-lithium-ion technologies due to the plateau in lithium-ion
tech. Graphene supercapacitors are one technology being explored, which may yield
low-cost, high-yield energy storage alternatives. Another promising technology is 22
21 Nield, David. "The Past, Present and Future of Smartphone Batteries." TechRadar. May 22, 2015. Accessed December 2015. 22 Harrop, Peter. "Supercapacitor Materials 20152025: Formulations, Forecasts, Roadmap, Companies, Materials." ID Tech Ex. July 2015. Accessed December 2015. http://www.idtechex.com/research/reports/supercapacitormaterials20152025formulationsforecastsroadmapcompanies000400.asp.
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ultrafast rechargeable aluminum-graphite battery currently being developed by Stanford
University researcher who indicate they have achieved 7,500 cycles without capacity
loss. Aluminum is also very low-cost, has low flammability and high-charge storage
capacity. Another promising technology is sodium-ion technology, which functions 23
similar to lithium-ion but relies on sodium which we will see is a much more abundant
resource in our analysis. 24
Key Materials:
Based on this survey of current and future consumer electronic technologies we
identified the following materials as most relevant to decision making for consumer
electronics energy storage researchers. As lithium-ion is expected to dominate the space
for the foreseeable future we felt lithium and other materials relevant to new lithium-ion
battery chemistries would be the most critical to analyze. Additionally, while it is unclear
when other technologies will begin to see widespread commercial use, we decided to
explore materials such as sodium and graphite relevant to novel technologies such as
sodium-ion batteries and aluminum-graphite batteries.
23 MengChang, Lin. "An Ultrafast Rechargeable Aluminiumion Battery." Nature.com. April 06, 2015. Accessed December 04, 2015. http://dx.doi.org/10.1038/nature14340. 24 "Future Batteries, Coming Soon: Charge in Seconds, Last Months and Power over the Air." Pocketlint. Accessed December, 2015. http://www.pocketlint.com/news/130380futurebatteriescomingsoonchargeinsecondslastmonthsandpowerovertheair.
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Automotive
As stated previously, much stands to be gained from advancements in
transportation related battery technology. To accomplish this, one of the most
promising technologies lies in electric vehicles (EVs). Electric vehicles not only reduce
the dependence on foreign oil but also reduce emissions of greenhouse gases and other
pollutants. Additionally, EVs can help spur economic growth, innovation, and job
growth.
Historically speaking, electrified road vehicles have been around for over 100
years; in fact, 1888 was the year that German engineer Andreas Flocken built the first
four-wheeled electric car. The growth in electric vehicle stock hit its historical peak of
30,000 in 1912, but by 1935, EVs become near extinct due to the predominance of
internal combustion engine vehicles and cheap petrol. It was not until 1997 that Toyota
began selling the Prius, which was the world’s first commercial hybrid car. Furthermore,
the global EV stock currently stands at over 665,000, which represents 0.08% of total
passenger cars. 25
Current Automotive Technology:
Electric vehicles today are powered by three main types of batteries: lead-acid,
nickel-metal hydride (NiMH), and lithium-ion. Lead-acid is the oldest type of
25 International Energy Agency. "Global EV Outlook 2015." 2012. Accessed December 2015. doi:10.1787/eco_surveyspol2012graph53en.
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rechargeable battery and also the most mature battery technology. It is cheapest of the
three options but has the lowest energy density and the longest recharge time. However,
lead-acid technology is phasing out and fewer electric vehicles employ it. Nickel-metal
hydride is another type of
battery used to power electric
vehicles. It is mainly used in
hybrid vehicle models such as
those produced by Honda and
Toyota. Currently, nickel-metal
hydride batteries offer the best
compromise in terms of energy
capacity, price, and size of
battery. It has the fastest
recharge time and relatively
high self-discharge rate . 26
Source: “BU-107:Comparison Table of Secondary Batteries. 27
26 Cready, Erin. Technical and Economic Feasibility of Applying Used EV Batteries in Stationary Applications. Report. Sandia National Laboratories, 2003. Accessed December 2015. http://www.rmi.org/Content/Files/Technical%20and%20feasible.pdf. 27 "BU107: Comparison Table of Secondary Batteries." Accessed November 28, 2015. http://www.virlab.virginia.edu/Energy_class/Lecture_notes/Electrification_of_Tranportation_Supporting_Materials /Secondary (Rechargeable) Batteries – Battery University.pdf.
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In the near future, an increasing number of electric vehicles will be powered by
lithium-ion batteries. The technology is most famously utilized in fully electric vehicles
such as those produced by Tesla. Lithium-ion batteries provide the highest specific
energy and energy density of the three modern automotive battery types. The cobalt
cathodes in lithium-ion cells hold twice the energy of nickel-based batteries and four
times as much as lead acid batteries. It is also the most expensive even though the cost
of lithium-ion batteries have decreased substantially over the past decade. 28
One of the major concerns, however, with lithium-ion batteries is safety. Like
many other energy storage technologies, lithium-ion carries a risk of battery failure and
possibly combustion. Combustion is generally the result of a process called thermal
runaway in which the battery overheats as the result of being overcharged, discharged
too quickly, or short circuiting. The temperature inside the battery rises to the melting
point of the metal and causes a fire. Such accidents are major concerns for the electric
automobile industry in general because a single battery fire can tarnish public image
and setback the adoption of the technology for many years. 29
Future Automotive Technologies
While most experts agree that lithium-ion will dominate the automotive energy
storage landscape in the near future, many promising potential technologies have been
identified in recent years.
28 Evarts, Eric C. "Lithium Batteries: To the Limits of Lithium." Nature.com. October 28, 2015. Accessed December 2015. doi:http://dx.doi.org/10.1038/526S93a. 29"Lithiumion Safety Concerns." Battery University. http://batteryuniversity.com/learn/article/lithium_ion_safety_concerns.
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1. Perovskite Solar Cells:
Perovskite solar cells is one such technology. With lithium-ion vehicles, one of
the main challenges is recharge time. Until batteries can recharge quickly it will be
difficult for them to compete with traditional internal combustion engines. Perovskite
solar cells are one breakthrough technology addressing this issue. The cells use solar
energy to produce electricity which is then stored directly in the cell, providing more
efficient conversion than can normally be achieved with traditional systems in which
the solar panel and battery are separate components. This can increase the viability of
electric vehicles by both extending battery life and enabling vehicles to recharge
themselves when not in use.
The cells include a perovskite structured compound made of inorganic lead or tin
halide-based materials. A perovskite structure is anything that has the structure ABX3,
which has the same crystallographic structure and form as true perovskite (a mineral
composed of calcium, titanium and oxygen in the form CaTiO3. The A represents an
organic cation (methylammonium), the B is a big inorganic cation (usually lead), and
the X3 is a slightly smaller halogen anion (usually chloride or iodide). The materials used
to make perovskite solar cells, including methylammonium lead halides, are very cheap,
and the manufacturing costs are also low. According to a recent study, the efficiency
limit of perovskite solar cells can reach 31%, which is very high compared to
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alternatives. These cells are also very attractive for commercial purposes, and many 30
companies are starting to manufacture them at scale.
Most recently, (Xu, Chen & Dai) demonstrated that the solar cell technology 31
provides a great way to self-charge lithium-ion batteries in electric vehicles on a large
scale. Before this study, the photo-charging lithium-ion batteries had low overall
photo-electric storage-conversion efficiency and poor cycling stability. However, they
successfully used perovskite solar cell packs to photo-charge lithium-ion batteries.
Specifically, the solar cell pack with four single CH3NH3PbI3 cells with a battery
containing a LiFePO4 cathode and Li4Ti5O12 anode exhibited a high specific capacity and
rate capability. The perovskite solar cell with lithium-ion battery units had a high
photo-electric conversion and storage efficiency of 7.8% and excellent cycling stability
with AM1.5G for 17.8h. In other words, these results clearly show that this technology
has outperformed all other types of lithium-ion battery with solar cells.
2. Automotive Flow Batteries:
Another prospective technology is the automotive flow battery, which is currently
being developed at General Electric. Flow batteries could potentially address many 32
problems associated with lithium-ion batteries, particularly those associated with
30 "Perovskites and Perovskite Solar Cells: An Introduction." Ossila. Accessed December 04, 2015. http://www.ossila.com/pages/perovskitesandperovskitesolarcellsanintroduction. 31 Xu, Jiantie, Yonghua Chen, and Liming Dai. "Efficiently Photocharging Lithiumion Battery by Perovskite Solar Cell." Nature.com. August 27, 2015. Accessed December 04, 2015. doi:10.1038/ncomms9103. 32 "Early Model of WaterBased Flow Battery." Digital image. General Electric. March 2015. Accessed December
2015. http://media.mnn.com/assets/images/2015/03/quant waterbased flow battery.jpg.
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driving range and safety. In the next section we
discuss flow battery technologies more
extensively as a grid-scale storage technology,
but the basic architecture is a battery that utilizes
liquids electrodes rather than the solids found in
traditional designs. The use of liquid electrodes
provides a significant advantage in that it will
potentially be possible to recharge the batteries
instantaneously by simply replacing the
discharged electrodes with a charged solutions, just like filling up a traditional
combustion engine at a gas station. Additionally, this technology is expected to be very
safe due the absence of combustible components and separation of reactive liquids into
separate tanks. According to General Electric, their flow battery could reduce costs by
75% relative to modern lithium-ion standards and achieve a range of 240 miles. 33
Key Materials:
Based on our survey of current and future automotive technologies we identified
the following materials as most relevant to decision making in the automotive energy
storage space. As lithium-ion is expected to dominate the space for the foreseeable
future we felt materials relevant to lithium-ion battery chemistries would be the most
33 Liu, Ping, and Sergei Kniajanski. "WATERBASED FLOW BATTERY FOR EVS." Arpae. August 21, 2013. Accessed December 2015. http://arpae.energy.gov/?q=slicksheetproject/waterbasedflowbatteryevs.
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critical to analyze. Although there are several different types of lithium-ion batteries,
each with its own advantages and disadvantages, the most prominent for vehicles are
lithium-nickel-cobalt-aluminum, lithium-nickel-manganese-cobalt, lithium-manganese
spinel, lithium-titanate, and lithium-iron phosphate. In addition, the standard
lithium-ion battery has anodes made of graphite. 34
35
Grid Scale Storage
Some of the most important potential applications of battery technology are those
concerning energy storage at a grid level. As previously discussed, many of the grid’s
current deficiencies could be resolved by grid scale battery technology. Grid scale
batteries would address the issue of fluctuating energy demand which is at the heart of
most of the grids current limitations. Having a cheap and efficient method of storing
excess energy from wind or solar farms during times of low demand would allow this
energy to be tapped later when there is more demand than energy being pumped into
34"Early Model of WaterBased Flow Battery." Digital image. General Electric. March 2015. Accessed December 2015. http://media.mnn.com/assets/images/2015/03/quant waterbased flow battery.jpg 35Maurice, H. St. Energy Storage Study. Report. Accessed December 2015. http://arena.gov.au/files/2015/07/AECOMEnergyStorageStudy.pdf.
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the grid. Currently, power providers must carefully regulate how and when they produce
electrical energy in response to fluctuating demand. Doing this, however, causes many
inefficiencies resulting from highly variable rates of production of power. Having a more
constant rate of energy production, and simply storing that which is not used, would
allow non-renewable sources of production to act much more efficiently and allow
renewable sources to be tapped to their fullest potential.
Current Grid Scale Technologies:
World-wide grid scale energy storage is currently dominated by pumped hydro
technology in dramatic fashion. The Department of Energy’s Global Energy Storage
Database indicates that as of October 26th, 2015 nearly 96% of global grid scale energy
storage comes from pumped hydro. 36
37
Pumped hydro systems work by using energy to pump water uphill into reservoirs
during periods of low-demand. The reservoirs can then be later emptied in order to
generate hydroelectric electricity. The technology is most prominently deployed in 38
36 Sandia National Laboratories. "Global Project Installations Over Time." Department of Energy. Accessed December 2015. http://www.energystorageexchange.org/projects/data_visualization. 37 Ibid. 38 Fairley, Peter. "A Pumped Hydro EnergyStorage Renaissance." IEEE Spectrum. Accessed December, 2015. http://spectrum.ieee.org/energy/policy/apumpedhydroenergystoragerenaissance.
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Japan, China, and the United States which have roughly 25.5, 23.7, and 21.4 GW of
storage capacity respectively. While Pumped hydro is certainly an innovative 39
technology, geographic limitations make it infeasible on a larger scale in the same way
that hydro electric generation is limited.
Future Grid Scale Technologies:
Due to these fundamental limitations of pumped hydro grid storage, many alternative
technologies are being investigated. Two of the most promising are grid scale flow
batteries and liquid metal batteries, both of which are anticipated to become cheap and
highly scalable methods to store large amounts of energy in the future.
1. Flow Batteries:
There are many different types of flow batteries, but at its core, a flow battery
consists of two chemicals dissolved in liquids in two separate tanks, separated by a
membrane. Electricity is created through the exchange of ions across the membrane
from one liquid to another, carried to the electrodes. Electroactive elements are
dissolved in each electrolyte in both tanks, causing a difference in electrochemical
potential energy when pumped through the membrane. Varieties of flow batteries
include redox, hybrid, membraneless, organic, and polymer based.
One key feature flow batteries, specifically RFBs (Redox Flow Batteries), bring to
the table is their separation of power and energy within the cell. The power is contained
39 Ibid.
23
in the central stack where the anode and cathode reside, separated by the the
membrane. The actual chemical potential energy is stored in the electrolyte solutions
(analyte and catholyte) in two separate tanks . This structure allows for a more refined 40
optimization of each element of the battery cell over several key variables. It also allows
for easy modification to increase the storage, simply by increasing the amount of
electrolyte, to a theoretically limitless size. This can be done easily and relatively cheaply
compared to the cost of the stack which is the most expensive component . Compared 41
to other grid-storage technologies like compressed air energy storage or hydroelectric,
RFBs have no geographical restriction, making them very versatile.
Flow batteries certainly pose several advantages over other technologies. The
versatility in time of discharge, location, and applications are highlights. Another
advantage is that the infrastructure is very flexible to new advances. If, say, a newer
more efficient electrolyte “slurry” is invented, one could simply dump out the old
chemicals and replace it with the new liquid.
While flow batteries offer a number of potential advantages, there are some
inherent obstacles to overcome. Most of the cost of RFBs come from the active
chemicals in the electrolyte solution and the infrastructure of the device. From an
efficiency standpoint, they work at very high charge discharge efficiency. The main
drawback, however, is the power density. Currently they operate at decent power
densities, but future research is expected to improve current power densities which
40 Weber, Adam Z., Matthew Mench, and Jeremy P. Meyers. "Erratum To: Redox Flow Batteries: A Review." Springer. September 21, 2011. Accessed December 2015. doi:10.1007/s1080001103482. 41 Ibid.
24
would in turn drive down the cost of materials . Fortunately at a grid scale power 42
density is not a key issue since mobility is not a necessary feature and batteries will be
able to be scaled to enormous sizes.
Unfortunately, flow batteries currently still have capital costs that are high
enough to prevent them from meeting their cost-efficiency targets. However, the
Department of Energy has stated that in the “short-term” flow batteries will be able to
reach a LCOE of $.20 / kWh and a LCOE of $.10 /kWh. Naturally, government 43
agencies are known for setting unrealistically ambitious goals and timelines; many
scientists doubt the battery industry’s ability to meet these targets within the next few
years. Nevertheless, there is a consensus that costs will continue to drop and a shared
vision that flow batteries will eventually be able to beat the levelized cost of grid
electricity. 44
To reduce the LCOE of batteries, researchers are focused on lowering capital
costs. It is easy to see why flow batteries have such high capital costs: they are physically
huge. Providing electricity to an average-sized house would require a flow battery the
size of a small room. Flow batteries also have relatively low energy densities and rapid 45
discharge rates at the moment, which contributes to their increased cost. The
42 Ibid. 43 Electricity Storage Handbook in Collaboration with NRECA. Report. Albuquerque, 2013. http://www.sandia.gov/ess/publications/SAND20135131.pdf. 44 Casey, Tina. "UET Backs Up Energy Storage Challenge To Tesla With More Flow Battery Info (CT Exclusive Interview)." CleanTechnica. August 30, 2015. Accessed December, 2015. http://cleantechnica.com/2015/08/30/uetbacksenergystoragechallengeteslaflowbatteryinfoctexclusiveinterview/. 45 Mearian, Lucas. "Can Elon Musk's Battery Really Cut Your Power Lines?" Computerworld. May 05, 2015. Accessed December 2015. http://www.computerworld.com/article/2918235/sustainableit/canelonmusksbatteryreallycutyourpowerlines.html.
25
Department of Energy estimated the following average costs for several vanadium redox
flow batteries:
Reducing the size of flow batteries is a primary goal for researchers as they
attempt to reduce capital costs, and progress is being made slowly but surely. Flow
batteries are still at an experimental stage where numerous competing designs utilizing
different materials such as vanadium, bromine, zinc, titanium, manganese, and other
elements are being tested as possible prototypes. Because of the variety of designs and
the inherent difficulty of predicting the future, there are many different projections on
how quickly costs will be able to be reduced. The following is one such projection from
26
the Australian Renewable Energy Agency, which is typical of how energy experts are
projecting the future of battery research to unfold: 46
As we can see, it may take longer than the DOE is predicting for flow batteries to
actually reach a price level at which they can be commercialized in the mainstream. Of
course, different flow battery designs also have vastly different capital costs. One
estimate states that these differences among flow batteries have lead to a current
disparity in LCOEs among them ranging from $.25 / kWh to $1.00 / kWh. 47
There are already several firms who claim to be able to meet the DOE’s targets for
flow battery LCOEs. For example, UniEnergy Technologies says that its batteries have a
levelized cost of electricity of just $.083 / kWh. While we must treat the claims of these 48
firms with suspicion, as some have run into financial trouble and been run out of
business, it is encouraging to see such optimism and healthy competition among battery
46 Maurice, H. St. Energy Storage Study. Report. Accessed December 2015. http://arena.gov.au/files/2015/07/AECOMEnergyStorageStudy.pdf. 47 Ibid. 48 “UET Backs Up Energy Storage Challenge to Tesla With More Flow Battery Info”
27
researchers. There are also projections that indicate a 5-year median decrease in capital
costs of flow batteries of 38%, with more optimistic projections suggesting a 58%
decrease. 49
Despite the uncertainty on timelines and differences in design, it is clear that flow
batteries will eventually be able to challenge lithium-ion, although their potential uses
may not be as widespread at first. Flow batteries will at first be primarily suited for
larger scale uses such as peak shaving on the grid and storing excess renewable energy
from wind and solar sources. We are still quite a ways off from being able to produce
flow batteries small enough for uses such as powering automobiles.
2. Liquid Metal Batteries:
Another promising battery technology for potential grid scale applications are
liquid metal batteries. They are composed of two liquid, rather than solid, metals which
act as electrodes separated by a molten salt electrolyte. These three components are
combined in one container, but self-segregate into layers due to their differing densities.
When discharging, the negative electrode is oxidized and reduced in thickness while the
positive electrode increases in thickness. This happens because the positive electrode
forms an alloy of the two metals as the cations are conducted across the molten salt
electrolyte . Due to the necessary specific properties of each of these materials, there 50
are constraints which must be met. For the electrodes, the metal must have a reasonably
achievable melting point of under 1000 degrees celsius and a boiling point greater than
49 Tyskiewiczd. "Lazard LCOE." Lazard. Accessed December 2015. https://www.lazard.com/media/2391/lazardslevelizedcostofstorageanalysis10.pdf. 50 Ibid.
28
25 . Second, they must be sufficiently electrically conductive, reaching a minimum 51
conductivity greater than that of the molten salt electrolyte. Third, they must be
nonradioactive such that the elements occur naturally in a stable isotope form. An ideal
liquid metal battery combines two metals which provide the greatest difference in
electro positivity and negativity such that the electrochemical potential energy is
maximized while simultaneously having low melting points so as to lower the energy
needed to maintain the liquid metal state.
Liquid metal batteries have several advantages over traditional battery
compositions. For one, the necessarily liquid state of these batteries allows for extremely
fast charge-transfer kinetics and highly efficient transfer of charge . They are also 52
economically advantageous as they are relatively low-cost since most of the materials
are abundant and inexpensive and the production is fairly easy. Additionally, the
changing state of the electrodes from alloy back to independent elements greatly
minimizes the degradation of the electrodes, extending the potential cycle lifetime to an
unprecedented level . These advantages make liquid metal batteries extremely viable 53
candidates for grid-level storage devices. There are however, a few disadvantages. The
main drawback is the operating temperature of these devices. Because all the elements
must be in liquid state, the battery must be constantly kept at a temperature at or above
the melting point. Another issue is that the batteries have a theoretically low energy
51 Kim, Hojong. Liquid Metal Batteries: Past, Present, and Future. Report. Accessed December 2015. Liquid Metal Batteries: Past, Present, and Future Hojong Kim, Dane A. Boysen, Jocelyn M. Newhouse, Brian L. Spatocco, Brice Chung, Paul J. Burke, David J. Bradwell, Kai Jiang, Alina A. Tomaszowska, Kangli Wang, Weifeng Wei, Luis A. Ortiz, Salvador A. Barriga, Sophie M. Poizeau, and Donald R. Sadoway Chemical Reviews 2013 113 (3), 20752099 DOI: 10.1021/cr300205k. 52 Ibid. 53 Ibid.
29
density and are likely quite sensitive to motion and could be dangerous if they
malfunction . While these downsides are a concern for automotive and other 54
individualized applications, they can be minimized in a highly controlled and regulated
environment such as grid-level storage. For one, grid storage facilities are large and
regulated closely, minimizing the risk of motion or leaking. The low energy density is
also less of a concern for grid storage. Since size is not a significant restriction, the most
important attribute of the battery is its ability to hold and deliver charge efficiently. If
the battery has a low energy density then one could simply scale it up to whatever size is
needed.
Key Materials:
As previously mentioned batteries make up an extremely small proportion of the
current grid storage due to high costs and shorter lifespans. Even so there are promising
technologies. Our survey of flow and liquid metal battery technologies indicated that the
most promising potential technologies relevant to grid scale energy storage currently
being investigated make use of compounds containing nickel, vanadium, sodium,
bromine, and lithium.
54 Ibid.
30
IV. Analysis of Materials Markets
Given this survey of potential battery technologies it is clear that energy storage
researchers have tough decisions ahead for them in terms of which technologies to
pursue further. As previously mentioned, in addition to technological viability, a central
issue for emerging battery technology is commercial viability. Battery technologies rely
on a wide range of basic materials and as consequence the economics of a given battery
design are directly tied to those of its component materials. If a design relies on
materials with low global production capacities or commodities controlled by small
groups with substantial market power, it is unlikely the technology will be feasible at
scale regardless of how well it performs in test. In order to aid in the process of
identifying technologies most likely to see widespread adoption we analyzed the markets
for basic materials at the heart of the energy storage technologies that we surveyed.
Metrics and Methodologies:
The main aspects of these markets we sought to understand and the
methodologies we used to do so were as follows:
1. Price volatility:
Stability of prices will be critical to the success of any battery technology as price
stability allows for the “strategic long term planning by households, governments,
31
businesses and societal institutions” necessary to drive adoption. The benefits of 55
battery technology often take many years to offset upfront costs. Consequently,
uncertainty surrounding the long-term economics of a given technology causes
individuals to discount its value, creating significant barriers to adoption.
A commercially viable battery technology then will be one which has stable
prices. A battery technology which has stable prices is one for which the underlying
commodity prices are stable. To assess the stability of prices we calculated the
annualized price volatility for each commodity in consideration as follows:
where marks the total number of observations, marks the th observation, is theT xi i x
mean observed price, and is the number of observations per year.n
2. Market Power of Suppliers:
The market power of suppliers is an additional factor that determines the price
behavior of a commodity. One doesn’t need to look far to see the risks associated with
such market power, the prices of commodities such as oil and potash are frequently
throttled by small groups of powerful suppliers to devastating effect on the consumers
which rely upon them.
55 “Energy, Society and Science: The fiftyyear scenario”, 54.
32
To analyze the market power risk associated with each material we calculated the
Herfindahl-Hirschman Index of each commodity market. The Herfindahl-Hirschman
Index (HHI) is a measure of market concentration frequently used in the economic
analysis of competition, most commonly in the case of antitrust investigations. The HHI
of a given industry is calculated as the sum of the squared market shares of each firm in
the industry:
where is the number of firms in the industry and is the market share of the thN si i
firm. As such, the score gives increased weight to singularly large firms and ranges from
0.0 to 1.0. The Horizontal Merger Guidelines put forward by the by the United States
Department of Justice denotes markets to be ‘moderately concentrated’ with an HHI of
0.15-0.25, and those greater than 0.25 to be ‘highly concentrated’. 56
3. Economic Resilience:
Lastly, we analyzed the resilience of the given commodity to fluctuations in the
market. Electricity is a fundamental driver of economic productivity. It is important that
grid systems are resilient to economic downturn to avoid compounding the effects of
recessions or depressions.
56"HerfindahlHirschman Index." U.S Department of Justice. July 29, 2015. Accessed December 2015. http://www.justice.gov/atr/herfindahlhirschmanindex.
33
We used beta, a measure of the volatility of an individual security as compared to
that of the overall market, to measure how the performance of commodity producers
moves with the market as a whole. We calculated beta as:
where is the daily returns of a producer, and is the daily returns of an appropriateri rm
market index such as the S&P 500. A beta of 1 indicates movements in line with the
market. A beta less than 1 indicates smaller movements than the market and a beta
greater than 1 indicates stronger movements than the market. A negative beta
corresponds to the strength of movements discussed above, but in a countercyclical
manner. That is, a beta of -1 would indicate that the price of the security moved in
magnitudes similar to those of the market but performed well during market downturns
and poorly during market upturns.
Betas closer to zero are preferable for suppliers of battery components as they indicate
the producer’s reliability will be consistent during both periods of growth and economic
downturn.
34
Assumptions:
In order to calculate these metrics we made certain assumptions. The ones most
key to our analysis were as follows.
1. Volume as a proxy for market share:
Since many mining companies are private and most nations do not disclose their
revenues from mining operations it is difficult to calculate market shares for the
Herfindahl-Hirschman Indices using the standard definition of market share as revenue
relative to market size in USD. Additionally, changes in commodity prices over time
makes calculating a revenue figure from production levels unreliable. In our calculation
of HHIs we assumed that the volume of a material produced by a single supplier relative
to total production levels was a strong proxy for market share in terms of revenue
figures. We felt this assumption was justified as basic material products are by definition
not significantly differentiated. Consequently, suppliers sell their products at very
similar prices on average and volume is an adequate proxy for revenue.
2. National production in place of private production:
We decided that in the case of basic material markets a modified version of the
Herfindahl-Hirschman Indices calculated based on national shares of production would
be more appropriate than the traditional model calculated based on the market shares
of firms. This is because commodity markets are the most common targets of any
35
industry for nationalization. As such, market risk is more accurately reflected by the 57
concentration of a resource into the hands of a given nation.
3. Producers as a proxy for prices:
While it is easy to analyze the prices of exchange-traded metals, many materials
are traded through individual private contracts. As such, historical daily price data is not
available. In these cases, to calculate metrics such as price volatility and beta we
assumed the price movements of mining companies with operations concentrated in
these single commodities provided adequate proxies. We felt this was justified as the
price movements of mining companies are extremely correlated with those of their
underlying commodities. In the case of gold for instance the price of publicly traded
companies exhibit average correlations with the price of gold of 0.72 and the price of
gold equity indices exhibits an even higher average correlation of 0.80. 58
Materials Analysis
Lithium:
Lithium is one of the key components of a Lithium-ion battery. Since the market
for lithium-ion batteries has been and is expected to grow in the foreseeable future, the
57 Privatization and Nationalization Cycles. Rutgers University, NBER, World Bank. Econweb. July 2009. Accessed December 2015. http://econweb.rutgers.edu/rchang/PNJul_20_09.pdf. 58 Nangolo, C., and C. Musingwini. Empirical Correlation of Mineral Commodity Prices with Exchangetraded Mining Stock Prices. © The Southern African Institute of Mining and Metallurgy. School of Mining Engineering. July 2011. Accessed December 2015. http://www.saimm.co.za/Journal/v111n07p459.pdf.
36
price of lithium is important for our materials analyses. Aside from batteries, which
make up 31% of the global demand for lithium, the other main uses are ceramic and
glass, which accounted for 35% of the lithium demand in 2014. 59
Global Supply:
It is known that lithium is a finite resource so the supply of lithium is important
to our analysis. Although there is no government stockpile of lithium, production of
lithium has grown across the globe. In Argentina and Chile, production increased 15%
each due to increased demand for lithium ion batteries. China and Australia also saw the
production of lithium increase in 2014.
Global Demand:
Lithium consumption in 2014 was around 33,000 tons; a 10% increase from
2013. This consumption is expected to increase over the coming years. Even when the
demand has steadily grown, the price has remained relatively constant due to the rise in
59 "Mineral Commodity Summaries 2015." Lithium Commodity Summary, 2015. Accessed December 2015. doi:10.3133/70140094.
37
lithium’s supply. The U.S. Geological Survey estimated that the world has enough
reserves of lithium for 365 years of current global production of 37,000 tons per year.
Herfindahl-Hirschman Index:
Using our previously discussed methodology we calculated the HHI for lithium as
follows:
This indicates that the lithium market is highly concentrated by the US
Department of Justice’s Horizontal Merger Guidelines.
Price Behavior, Annualized Volatility, and Beta:
Because it is hard to get precise data on day to day movements on the price of
lithium, we use an exchange traded fund (ETF), Global X Lithium (LIT), as an estimator
for the price movements of lithium. Using our previously outlined methodology we find
that the annualized volatility for lithium is 24.15%. Using the historical daily price data
for LIT and the S&P 500 over the past five years, we calculated a beta of .099, indicating
38
a small positive correlation between the price of lithium and the price of the S&P 500,
but in general, that lithium prices are resilient to swings in the general market. Over the
past five years average lithium prices have been observed as follows:
Risks:
The most significant risk facing lithium supply is growing competition for the
resource. Lithium supply security is becoming a top concern for technology companies
in Asia, especially those companies that supply batteries and electric vehicles. Countries
as well are well aware of the importance of lithium-ion batteries in the near future and
as such are taking steps to ensure adequate lithium supplies. Consequently there is a
significant risk of hoarding by private companies and nations in the near future.
However, there are substitutes for lithium which may diminish the threat of this trend;
some examples are calcium, magnesium, mercury, and zinc as anode materials in
batteries. 60
Graphite:
Graphite is a metal that is used widely in standard lithium-ion batteries. It is
often called the “18650 cell”, which is the type of cell that Tesla uses for its electric
60 "LithiumIon Batteries: Possible Material Demand Issues." Digital image. Argonne National Laboratory. Accessed December 2015. http://www.rmi.org/Content/Images/Lithium%20ion.PDF.
39
vehicle batteries. The primary material for the anode part of the cell is graphite, which
makes up 16% of the entire cell. Other than batteries, other uses for graphite include
brake linings, foundry operations, and lubricants. 61
Global Supply:
The world currently has 110 million metric tons of graphite according to the
United States Geological Survey. In 2014, China produced 67% of the world’s graphite
and consumed 25% while production grew in Canada, China, Madagascar, Mexico,
Turkey and Zimbabwe in 2014.
Global Demand:
The worldwide demand for graphite grew throughout 2012 to the present, which
resulted from macroeconomic growth and its impact on companies that use graphite. In
61 "Materials and Processing for Lithiumion Batteries." TMS. http://www.tms.org/pubs/journals/jom/0809/daniel0809.html.
40
terms of import of natural graphite, Mexico, China, Canada, Brazil, and Madagascar
accounted for 96% of the tonnage of total global imports of graphite. 62
Herfindahl-Hirschman Index:
Using our previously discussed methodology we calculated the HHI for graphite as
follows:
This indicates that the graphite market is highly concentrated by the US
Department of Justice’s Horizontal Merger Guidelines.
62 Mineral Commodity Summaries, 2015. S.l.: Geological Survey (USGS), 2015. Accessed December 2015. http://minerals.usgs.gov/minerals/pubs/commodity/graphite/mcs2015graph.pdf.
41
Price Behavior, Annualized Volatility, and Beta:
We used data from S&P 500 and GrafTech International Ltd (Symbol: GTI),
which sells graphite, from August 13, 2010 to August 14, 2015 because there was no data
for this company after August 14, 2015. Using the methodology stated, we get an
annualized price volatility of 49% and a beta value of 1.31. This means that the price of
graphite is sensitive to the market conditions and can vary widely year over year.
Risks:
As we can see from the price patterns, the economy has a great effect on the price
of graphite. So as macroeconomic conditions strengthen, the price of graphite rises.
There are no signs of government stockpiling graphite even as the demand for graphite
is rising. However, there are substitutes for natural graphite used in batteries, including
synthetic graphite powder and secondary synthetic graphite from machining graphite
shapes. 63
Sodium:
Sodium is an essential component of many current liquid metal battery
chemistries, both as an electrode and as a component of salt electrolytes. It is a favored
63 Mineral Commodity Summaries, 2015. S.l.: Geological Survey (USGS), 2015. Accessed December 2015. http://minerals.usgs.gov/minerals/pubs/commodity/graphite/mcs2015graph.pdf.
42
candidate for electrodes in future battery chemistries, assuming difficulties related to its
solubility are overcome . Pure sodium is highly reactive and consequently it is typically 64
found and harvested as a compound in nature, the most common being sodium chloride
(NaCl), from which pure sodium can then be derived through a process of electrolysis.
We center our discussion of price and market dynamics around NaCl as a proxy for pure
sodium as it is a prominent commodity and more reliable data is available.
Global Supply:
Global sodium chloride resources are tremendous and virtually inexhaustible,
making sodium all the more attractive as a material for battery technologies. These
extensive reserves are predominantly the result of the significant salt content of the
earth’s oceans and substantial continental salt deposits. Most nations in the world
produce sodium chloride to some extent, the United States itself being a major
producer.
64 Liquid Metal Batteries: Past, Present, and Future.
43
65
Global Demand:
Sodium has an extremely broad range of end uses outside of battery technologies
ranging from common culinary applications to complex industrial processes such as
paper-pulping . Global demand for sodium chloride is expected to grow at pace with 66
increased demand from developing nations, reaching annual production levels of 324
million metric tons by 2018. The predominant industry driving this growth will be
chemical manufacturing which made up 60% of demand in 2013. 67
Herfindahl-Hirschman Index:
Using our previously discussed methodology we calculated the HHI for sodium
chloride as follows:
65 "Salt: Mineral Commodity Summaries 2015." Mineral Commodities Summaries, 2015. Accessed December 2015. doi:10.3133/70140094. 66 "Salt Statistics and Information." USGS Minerals Information: Salt. Accessed December, 2015. http://minerals.usgs.gov/minerals/pubs/commodity/salt/. 67 Salt: Mineral Commodity Summaries 2015.
44
This indicates that the sodium chloride market is unconcentrated by the US
Department of Justice’s Horizontal Merger Guidelines.
Price Behavior, Annualized Volatility, and Beta:
Sodium chloride is extremely commodified and as such its unit prices are quite
low. Over the past 6 years domestic salt prices have averaged around $46.44 per metric
ton.
68
Because NaCl is not exchange traded and there are no equity indices for salt, we
assumed the United States’ largest publicly traded salt producer, Compass Minerals
(CMP) as a proxy for NaCl prices. Using the prices of CMP and the S&P 500 we
68 Freed, Ben. "Huge Salt Price Increases Will Squeeze Road Budgets across Michigan." Mlive.com. Accessed December, 2015. http://www.mlive.com/news/annarbor/index.ssf/2014/09/huge_salt_price_increases_sque.html.
45
calculated daily returns over the 5-year market period from December 6th, 2011 to
December 3rd, 2012. We calculated annualized volatility as 15.3% and beta to be 0.884.
Risks:
Considering the above, we assess that there are relatively few risks associated
with dependence upon sodium as a battery component. Extreme commodification of key
raw materials such as NaCl means that there is significant buyer power in the market.
While the market may face unanticipatedly high prices in given individual years due to
events such as snow related spikes in rock salt demand, in general the global untapped
resources are sufficiently large that supply will be able to adjust to meet systemic
demand relatively easily. Sodium is additionally attractive as it exhibits reasonable price
volatility and is a sufficiently large industry such that contracts are readily available to
lock in prices and further decrease risk.
Vanadium:
Vanadium is a chemical element that is essential to many flow battery designs.
These batteries make use of vanadium’s ability to exist in various oxidation stages and
utilize it to store potential chemical energy. The international market demand for 69
vanadium is primarily driven by a desire to use it hardening purposes in steel alloys.
However, as flow battery development continues and their use expands, battery
producers will become another major source of demand for vanadium. 70
69 Knight, Laurence. "Vanadium: The Metal That May Soon Be Powering Your Neighbourhood BBC News." BBC News. Accessed December 04, 2015. http://www.bbc.com/news/magazine27829874. 70 "Vanadium." Encyclopedia of Metalloproteins, 2013. doi:10.1007/9781461415336_101311.
46
Global Supply:
The United States is a producer of vanadium and there are firms within the
United States that produce nearly every sort of vanadium commodity, including those
specifically required for battery production. However, by far the largest sources of
vanadium are found in Russia, China, and South Africa, with China producing about
twice as much as the other two countries each. The US is heavily dependant on imports
for its vanadium supply, most of which come from South Africa. 71
Global Demand:
Demand for vanadium is expected to double over the next decade as demand for
high-grade steel continues to increase. About half of the world’s vanadium demand is 72
expected to come from Asia, with China leading the way. Demand will also increase as 73
Europe’s economic recovery continues and the construction industry begins to ramp up;
construction in the developing world will also be a driver of growth. Furthermore,
projected increases in the orders of airplanes and cars will increase demand for steel
alloys containing vanadium. 74
71 Ibid. 72 "Demand for Vanadium to Double in next Decade." InvestorIntel. Accessed December, 2015. http://investorintel.com/technologymetalsintel/demandvanadiumwilldoublenextdecade/. 73 "Vanadium: Market Outlook to 2025." Vanadium: Market Outlook to 2025. Accessed December 04, 2015. http://www.giiresearch.com/report/ros122028globvanadium.html. 74 "Vanadium Financials." Largo Resources, November 2013, 12227. Accessed December 2015. doi:10.1002/9781118268209.ch10.
47
Herfindahl-Hirschman Index:
Using our previously discussed methodology we calculated the HHI for vanadium
as follows:
This indicates that the vanadium market is highly concentrated by the US
Department of Justice’s Horizontal Merger Guidelines.
Price Behavior, Annualized Volatility, and Beta : 75
Vanadium is a relatively expensive mineral compared to most of the others we
are examining. In 2013, a metric ton of vanadium had an average price of $23,800. The
price of vanadium has been shown to be extremely susceptible to shocks in the market.
Two incidents in the past twenty years, when a new application in steel was discovered
for vanadium and when the financial crisis of 07-08 occurred, both caused the price of
vanadium to skyrocket many times over before prices were able to stabilize at more
75 We could not find an index that accurately models the price of vanadium. There are no ETFs or companies that solely produce vanadium.
48
normal levels. Supply of vanadium has also been quite volatile, often increasing or 76
decreasing by double digit percentages from year to year. In recent years, the price of
vanadium has been fairly stable, decreasing slowly and steadily as production has
increased rapidly. However, worldwide reserves of vanadium are ample and should be
able to withstand demand for at least the next century. 77
Risks:
We can conclude that there are several risks involved in pursuing vanadium
powered battery technologies. First, despite recent downward trends that are expected
to continue into the future, the price of vanadium is still much higher than those of
other elements used in battery production. Second, there is a realistic risk that an
economic or technological shock could hugely disrupt the cost of vanadium at some
point in the future. Lastly, although there is healthy international trade in vanadium at
the moment, it is not ideal that most of the world’s vanadium is produced in countries
with sometimes volatile and antagonistic relationships with the Western world, which is
where the battery research we are focused on is based. This provides some risk of a
geopolitical incident affecting vanadium supply at some point in the future and
disrupting its market.
76 "Vanadium Prices and Vanadium Price Charts." Investment Mine. Accessed December 2015. http://www.infomine.com/investment/metalprices/ferrovanadium/. 77 "Vanadium." Encyclopedia of Metalloproteins, 2013, 2293. doi:10.1007/9781461415336_101311.
49
Bromine:
Bromine is a chemical element that is used in several types of exciting new flow
battery designs, including zinc-bromine and membraneless hydrogen-bromine
batteries. The most popular uses for bromine are industrial products used in drilling,
water purification, and fire-fighting materials. Battery related uses of bromine do not
currently have a substantial effect on its market because these types of batteries are in
more experimental stages so they have not taken off in mainstream use yet. In the
future, a great deal of bromine could be demanded by battery producers if a technology
such as membraneless batteries is perfected and successfully commercialized. 78
Global Supply:
The US is one of the world’s leading producers of bromine and can easily supply
the amounts of bromine required for the related fields of battery research. The world’s
other top producers of bromine are China, Israel, Jordan, and Japan. Israel produces
nearly twice as much more than any of these other countries. The US has the capacity to
produce even more than Israel does. The US imports much more bromine than it
exports, and most of those imports come from Israel.
78 "Bromine." 2014 Minerals Yearbook. doi:10.1036/10978542.096700.
50
Global Demand:
China and the United States account for more than half of the world’s demand of
bromine. The rest of Asia has replaced Europe as the next biggest source of demand. 79
This is partly because many European countries have banned several products made
with bromine for environmental reasons. Demand for bromine is outpacing its supply
worldwide. Growth in global demand for bromine is being lead by China’s rapidly
expanding industrial sector, especially its oil industry. Global demand for flame 80
retardants using bromine is booming, but growth in this area may be tempered by the
perceived toxic nature of bromine.
79 "Bromine." Chemical Economics Handbook (CEH). Accessed December 04, 2015. https://www.ihs.com/products/brominechemicaleconomicshandbook.html. 80 "Bromine Market Opportunity." Gulf Resources Inc. Accessed December 2015. http://www.gulfresourcesinc.com/brominemarketopportunity.html.
51
Herfindahl-Hirschman Index:
Using our previously discussed methodology we calculated the HHI for lithium as
follows:
This indicates that the bromine market is moderately concentrated by the US
Department of Justice’s Horizontal Merger Guidelines.
Price Behavior, Annualized Volatility, and Beta : 81
Trade publications estimate that the average price for a metric ton of bromine
fluctuated between $3,500 and $3,900 in 2014. There has been a steep increase in the 82
price of bromine in recent years. Bromine costs are currently about quadruple what they
were a decade ago. This trend is expected to continue, with many companies around the
world recently raising their prices by over 20% this year. Production of bromine has 83
81 We could not find an index that accurately models the price of bromine. There are no ETFs or companies that solely produce bromine. 82 "Bromine." Mineral Commodities Summaries, 2015. Accessed December 2015. doi:10.3133/70140094. 83 "Investor Relations | News Release." Albemarle. March 26, 2015. Accessed December 2015. http://investors.albemarle.com/phoenix.zhtml?c=117031&p=irolnewsArticle&ID=2029057.
52
remained relatively flat and until recently has not increased in response to the price hike
that has been experienced. Price increases have been driven by a spike in global
demand, particularly in the oil drilling and water treatment industries. It is unclear how
long the trend of rising prices will last, because several major factors such as expected
new legal measures regulating the use of bromine-related products and instability in the
oil industry will greatly affect the price of bromine in years to come.
Risks:
There are several risks associated with pursuing bromine-related battery
technologies. These risks are primarily linked to the high degree of uncertainty
regarding future trends in the price of bromine. Very sensitive political issues such as
environmental protection and oil production are difficult to predict and will influence
the price of bromine massively. In addition, there are concerns about the ability of the
global supply chain to keep up with increases in bromine demand. However, this risk is
somewhat mitigated for U.S. based companies because the U.S. satisfies nearly all of its
bromine demand either from internal production or with imports from strong political
allies. 84
V. Consequences for Storage Technology
Given our analysis, it is clear that the dynamics of basic materials markets most
relevant to prospective battery technologies are complex and varied. We now revisit our
84 "Bromine." 2014 Minerals Yearbook. doi:10.1036/10978542.096700.
53
previous discussion of prospective battery technologies in light of our analysis of basic
materials market. To conclude our paper we discuss the points of our materials analysis
we believe to be most relevant to the decisions energy storage researchers will need to
make in terms of where to focus future research and development efforts.
Consumer Electronics:
While our survey revealed that the largest societal benefits stand to be accrued
from improvements in the transportation and grid scale storage spaces, the market for
personal electronics is tremendously large and is thus very relevant to decision making
in the energy storage space. Since lithium-ion seems likely to dominate the space for the
foreseeable future, and lithium-air the next leap in innovation, it is important that
researchers and private industry are aware of the risks associated with certain
unfavorable dynamics of the lithium marketplace. Our research indicated that the
market was exceptionally concentrated with a Herfindahl-Hirschman Index of 0.41388.
This means that national consolidation of resources and potentially collusive practices
of suppliers could potentially throttle supply if competition for lithium becomes too low.
This being said, there are favorable aspects to lithium’s market behavior as well,
particularly in that it has an exceptionally low beta of 0.099, indicating it does not vary
substantially with market downturns. This indicates that by coupling lithium with other
materials whose prices were decorrelated with lithium but correlated with the market,
54
battery manufacturers could achieve overall price stability in the mix of the materials
they used.
In addition to lithium-ion and lithium-air, we considered materials relevant to
aluminum-graphite and sodium-ion batteries, two promising future technologies we
identified in our initial survey. Following our analysis, it is clear that of the two,
sodium-ion is a much more promising technology from a basic materials perspective.
Firstly, the market dynamics for graphite seem precarious. The market is extremely
concentrated with a Herfindahl-Hirschman Index of 0.489. Additionally it exhibits
annualized price volatility of approximately 49%, much higher than that of sodium
which is approximately 15%. Sodium is additionally more favorable as its supply is
relatively inexhaustible and its market place unconcentrated as demonstrated by its
HHI of 0.13. Furthermore sodium exhibits higher resilience to market downturns with a
beta of 0.88 whereas the price of graphite varies substantially with a beta of 1.31,
although admittedly these difficulties could be overcome by coupling graphite with
materials the price of which were decorrelated with its own. Even so, given the above
considerations we feel that between sodium-ion and aluminum-graphite battery
technologies sodium-ion is significantly more promising from a basic materials
perspective.
55
Automotive:
Following our survey it was clear that most experts agree lithium-ion batteries
will power our electric vehicles in the near future. Although other types of electric
vehicle batteries like water based flow batteries exist, they will not be feasible
alternatives to replace lithium-ion ones anytime soon. The materials we analyzed in this
paper have great impact on the future of electric vehicle batteries. The most pertinent
materials for lithium ion batteries we analyzed are lithium and graphite. For lithium, we
found that the annualized volatility was was 24%. Compared to the S&P 500, we found a
beta of 0.099 using data of the Exchange Traded Fund called Global X Lithium (Symbol:
LIT) from the last 5 years. We also found a Herfindahl–Hirschman Index for Lithium of
0.42. These data show that lithium has little to no correlation with global
macroeconomic conditions and moderate volatility. In addition, the
Herfindahl–Hirschman Index indicates that a few countries hold major shares of
lithium in the world and have high market power to influence future prices of lithium.
Countries are already starting to hoard lithium in anticipation of future automobile
technology relying on lithium as one of the main materials to manufacture batteries. The
second main material, graphite, has an annualized volatility of 49%, a beta value of 1.31
compared to the S&P 500, and a Herfindahl-Hirschman Index of 0.49. This means that
the price of graphite varies greatly, is highly correlated with the global macroeconomic
conditions, and a select few countries hold most of the graphite reserves. These facts
suggest that graphite and lithium both run the risk of rising prices in the future due to
56
high HHI values. The high volatility of graphite also seems to suggest that this key
material for building anodes in batteries is somewhat unpredictable. Unless new battery
technology is developed, the material costs of building the battery will continue to rise in
the near future.
Grid Storage
After analyzing the materials, capital costs, and LCOEs associated with grid
storage battery technologies, we have concluded that there are promising avenues for
researchers in both liquid metal and flow battery technologies, both of which have their
advantages and downsides. Liquid metal batteries are within a few years of being
available for mainstream use and can have a positive effect on the electrical grid in the
near future. The materials associated with liquid metal batteries, such as sodium, are
produced worldwide in massive quantities, have very cheap prices, and have low
concentration indexes. Liquid metal batteries are currently cheaper than flow batteries
and can easily be scaled to meet energy needs, which means that it would be a wise
decision to invest in their development as a short-term boost to grid efficiency.
However, flow batteries have a much wider range of potential uses than liquid metal
batteries, whose only feasible use is for grid storage, which means that there is bigger
upside in their development. Flow batteries currently have high capital costs, but these
costs have been declining steadily and are expected to eventually become cheaper than
liquid metal and even lithium-ion batteries. As the cost and physical size of flow
57
batteries decrease, they can potentially be used not only for grid storage but also in
other areas such as in automobiles. Unfortunately, this stage in the development of flow
batteries is still far off and many hurdles need to be surpassed before it can be reached.
The fact that several key materials crucial for flow batteries such as bromine and
vanadium are produced in relatively small amounts within only a few countries
worldwide, have high concentration indexes, and have extremely expensive and volatile
prices poses a significant challenge to the development of flow battery technology. Thus,
while flow batteries have great upside and can truly revolutionize batteries in the future,
liquid metal batteries are a safer bet to create an immediate impact on the landscape of
battery technology and specifically on energy grid storage.
Further Inquiry:
This concludes our analysis of the basic materials markets most relevant to
emerging battery technologies. In light of our analysis and survey of technologies, we
think an interesting direction to proceed would be the analysis of basic material price
dynamics for those materials that appear in the same battery chemistries. Useful results
might be attainable through application of techniques from modern portfolio theory
which could help battery researchers identify complementary market relationships
between prospective materials.
58
VI. Appendix
Bromine Producer 2013 Production Squared Share of Global Production
United States n/a n/a
Azerbaijan 3,500 0.00008
China 110,000 0.07450
Germany 1,500 0.00001
India 1,700 0.00002
Israel 172000 0.18216
Japan 30,000 0.00554
Jordan 80000 0.03941
Turkmenistan 500 0.00000
Ukraine 4100 0.00010
TOTAL/HHI 403000 0.30182
Graphite Producer 2013 Production Squared Share of Global Production
United States n/a n/a
Brazil 95 0.00732
Canada 20 0.00032
China 750 0.45654
India 170 0.02346
Korea, North 30 0.00073
Madagascar 4 0.00001
Mexico 7 0.00004
Norway 2 0.00000
Russia 14 0.00016
Sri Lanka 4 0.00001
Turkey 5 0.00002
Ukraine 6 0.00003
Zimbabwe 4 0.00001
Others 1 0.00000
TOTAL/HHI 1110 0.48866
59
Iron Producer 2013 Production Squared Share of Global Production
United States 53 0.00029
Australia 609 0.03835
Brazil 317 0.01039
Canada 43 0.00019
China 1450 0.21738
India 150 0.00233
Iran 50 0.00026
Kazhakstan 26 0.00007
Russia 105 0.00114
South Africa 72 0.00054
Sweden 26 0.00007
Ukraine 82 0.00070
Others 127 0.00167
TOTAL/HHI 3110 0.27307
Lithium Producer 2013 Production Squared Share of Global Production
United States 870 0.00065
Australia 12700 0.13952
Argentina 2500 0.00541
Brazil 12700 0.13952
Chile 11200 0.10851
China 4700 0.01911
Portugal 570 0.00028
Zimbabwe 1000 0.00087
TOTAL/HHI 34000 0.41388
Manganese Producer 2013 Production Squared Share of Global Production
United States n/a n/a
Australia 2980 0.03469
Brazil 1120 0.00490
Burma 157 0.00010
60
China 3000 0.03516
Gabon 1970 0.01516
Ghana 533 0.00111
India 920 0.00331
Kazakhstan 390 0.00059
Malaysia 430 0.00072
Mexico 212 0.00018
South Africa 4300 0.07223
Ukraine 300 0.00035
Others 597 0.00139
TOTAL/HHI 16000 0.16988
Sodium Chloride Producer 2013 Production Squared Share of Global Production
United States 40300 0.02366
Australia 11000 0.00176
Brazil 7500 0.00082
Canada 12200 0.00217
Chile 6580 0.00063
China 70000 0.07138
France 6100 0.00054
Germany 11900 0.00206
India 16000 0.00373
Mexico 10800 0.00170
Poland 4430 0.00029
Spain 4440 0.00029
Turkey 5300 0.00041
Ukraine 6200 0.00056
United Kingdom 6700 0.00065
Others 42200 0.02594
TOTAL/HHI 262000 0.13660
Titanium (ilmenite) Producer 2013 Production Squared Share of Global Production
United States 200 0.00088
61
Australia 960 0.02035
Brazil 100 0.00022
Canada 770 0.01309
China 1020 0.02297
India 340 0.00255
Madagascar 264 0.00154
Mozambique 430 0.00408
Norway 498 0.00548
South Africa 1190 0.03127
Sri Lanka 32 0.00002
Ukraine 150 0.00050
Vietnam 720 0.01145
Others 60 0.00008
TOTAL (ilmenite) /HHI
6730 0.11447
Titanium (rutile) Producer 2013 Production Squared Share of Global Production
United States n/a n/a
Australia 423 0.40219
India 24 0.00129
Madagascar 8 0.00014
Malaysia 14 0.00044
Sierra Leone 81 0.01475
South Africa 59 0.00782
Ukraine 50 0.00562
Others 8 0.00014
TOTAL (rutile) /HHI
667 0.43240
Vanadium Producer 2013 Production Squared Share of Global Production
United States 591 0.00006
Australia 400 0.00003
China 41,000 0.26935
Russia 15,000 0.03605
62
South Africa 21,000 0.07066
Others 600 0.00006
TOTAL/HHI 79,000 0.37620
- Consolidated Data Table
Material HHI₂₀₁₃ Annualized Price Volatility Beta
Bromine 0.3018210198 n/a n/a
Graphite 0.4886648811 49% 1.31
Lithium 0.4138769896 24.15% 0.099
Sodium Chloride 0.1365965693 15.3% 0.884
Vanadium 0.3762008141 n/a n/a
- Technology Type Table
Technology Type Projects World
Wide Rated Power (GW)
Pumped Hydro Storage 345 179
Thermal Storage 198 3.61
Electro-mechanical 66 2.59
Electro-chemical 767 1.87
Hydrogen Storage 9 0.01
Total: 1385 187.08
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