Electrochemical Energy Storage beyond Li
Technology – Challenges and Perspectives
Maximilian Fichtner, Helen Maria-Joseph, Mario Ruben, Ping Gao, Zhirong Zhao-Karger
DPG Tagung, Bad Honnef, 2017
2DPG Tagung | 6. April 2017
Content
Introduction HIU
Motivation for the topic
New storage concept for Li ions
Post-Li Systems
Secondary Mg sulfur cells
Organic cathodes
Outlook
3DPG Tagung | 6. April 2017
HIU was founded on Jan 17, 2011 as a future
National Center of Excellence for Battery Research
Its mission is application-oriented basic research on new materials and
concepts for electrochemical energy storage.
Selected expertise is combined of all four partners, integrating research activities in
the areas:
Electrochemistry – Materials – Theory – Methods – Systems
research is integrated in the application-oriented programmatic research of the
Helmholtz Association (Research Area ENERGY).
The Helmholtz Institute Ulm and its mission
2016: 130 publications on Li (92) and post-Li (38) topics;
work was presented on 12 covers of international journals
4DPG Tagung | 6. April 2017
Scientific roadblocks / grand challenges are adressed
Systematic, rational approach leading to knowledge base and model development
(courtesy of A. Latz)
Enhancing the ionic mobility
in solids and liquids
Controlling the electronic
and ionic transfer across
interfaces
Enhancing the reversibility
on the microscale in the
solid state
Controlling the behavior
of systems beyond
thermodynamic stability
„Grand Challenges“ in Battery Research
5DPG Tagung | 6. April 2017
Research Topics at HIU
Electrochemistry
Methods
Systems
Theory
Materials
Metal
Deposition &
Interfaces
Insertion
Materials for Li
Li based
conversion
materials and
alloys
Post-Li
systems
6DPG Tagung | 6. April 2017
HIU New Building
http://www.hiu-batteries.de/de/
Location: Campus Ulm University
Labs & offices: 2.500 m2
Staff: about 110 employees(69 FTE)including 21 PIs
Inauguration: 31. Oktober 2014Total cost: 13 Mill €
7DPG Tagung | 6. April 2017
• New Storage Concepts
• New Materials
• Modelling
• Systems
Battery research at Ulm
ca. 300 employees at Ulm
• Fundamental electrochemistry
• Surfaces/Interfaces
• theoret. modelling
• System modelling
• Biggest experimental
cell manufacturing line
• Materials upscale
• Safety
e-Lab Ulm
Ulm in 2016:
205 publications on batteries, including 116 on Li ion and 40 on post-Li systems
8DPG Tagung | 6. April 2017
Evolutionary versus revolutionary materials
Gravimetric energy density (Wh/kg)
Li-ion
Ca/CoF3
Chlorides
Mg/CuCl2
Ca/CuCl2
Li/CuCl2
Fluorides
La/CoF3
Ca/CoF3
Li/FeF3
Li/CuF2
Selected battery
concepts
Lithium ion
batteries
Metal sulphur
batteries
Metal oxygen
batteries
Novel battery
chemistries
Liquid metal
batteries
LiC6 / NMC
Volu
metr
icene
rgy
density
(Wh/l)
Mg
batteries
Metal
Sulphur
Li/S
Mg/S
Metal-
Air
Li/O2
Mg/O2
Zn/O2Na/O2
Energy Transition and Energy Storage
9DPG Tagung | 6. April 2017
Weltweite Erzeugung von nicht-erneuerbaren Energieträgern
EWG, Fossil and Nuclear Fuels – the Supply Outlook (March 2013)
2017Million Tonnen Ölequivalent (Mtoe)
(including shale gas)
Why an energy transition?
10DPG Tagung | 6. April 2017
On a historical timescale…
The age of fossil (and nuclear fission) energy
11DPG Tagung | 6. April 2017
Why storage and which type?
short-term storage grid stabilization (fly wheels, capacitors)
hourly storage distriution of peaks over the day (pump storage, Batteries)
daily-/weekly storage seasonal storage (H2 in caverns, „power-to-gas“)
Solar
daily electricity
consumption
Wind
12DPG Tagung | 6. April 2017
TenneT Netz:40% of installed wind
energy in Germany
Number (2015): 26.772 turbines1)
Power: 45 GW1)
(> 27% of conventionalpower plant
capacity)
Electricity production 2015: 86 TWh2)
(13,3% of annual consumption)
1) Bundesverb. Windenergie, 2016
2) Strom-Report.de, 2016
Wind energy and the electric grid
13DPG Tagung | 6. April 2017
8,000 MWh
corresponds to ca. 4 Mio.battery cars on grid with 2 kWh buffer each
Pumped hydro
0
2000
4000
6000
8000
(MW)
Buffer for some minutes to hours
Pump storage Goldisthal,
Thüringen
= the largest hydropower
plant in Germany
Oct 1 Oct 3 Oct 5 Oct 7 Oct 9 Oct 11 Oct 13
40 Mio
PKW
14DPG Tagung | 6. April 2017
Energy content of cavern filled with hydrogen gas (2 Mio. m3
Volume):
600,000 MWh(= 3.6 Mio. tank fillings)
Only H2 allows efficient storage with supply over weeks.
H storage in salt caverns / power-to-gas
0
2000
4000
6000
8000
(MW)
Source: KBB Underground
Oct 1 Oct 3 Oct 5 Oct 7 Oct 9 Oct 11 Oct 13
H2
H2 Speicher
H2 + air (O2) + water
15DPG Tagung | 6. April 2017
Evolutionary versus revolutionary materials
Gravimetric energy density (Wh/kg)
Li-ion
Ca/CoF3
Chlorides
Mg/CuCl2
Ca/CuCl2
Li/CuCl2
Fluorides
La/CoF3
Ca/CoF3
Li/FeF3
Li/CuF2
Selected battery
concepts
Lithium ion
batteries
Metal sulphur
batteries
Metal oxygen
batteries
Novel battery
chemistries
Liquid metal
batteries
LiC6 / NMC
Volu
metr
icene
rgy
density
(Wh/l)
Mg
batteries
Metal
Sulphur
Li/S
Mg/S
Metal-
Air
Li/O2
Mg/O2
Zn/O2Na/O2
General situation in battery development
16DPG Tagung | 6. April 2017
Speicherung Erneuerbarer Energie mit Batterien
stationär
portabel
mobil
17DPG Tagung | 6. April 2017
Motivation for building “better” batteries
Sustainability
• elemental abundance
• recyclability
• ecological footprint
• toxicity
Better Batteries
• cost
• energy density
• power
• safety
18DPG Tagung | 6. April 2017
Theoretical and practical energy density
0
100
200
300
400
500
600
700
Gra
vim
etr
ic e
nerg
y d
en
sit
y
(Wh
kg
-1)
NMC lab
cell
NMC
cell levelNMC
battery
level
Materials
challenge Engineering
challenge
Fac
tor
4
NMC
theor.
value
NMC: Li(Ni,Mn,Co)O2
Theoretical
Practical
Values for NMC from: http://msdssearch.dow.com
19DPG Tagung | 6. April 2017
Gravimetric energy density (Wh/kg)
Li-ion
Ca/CoF3
Chlorides
Mg/CuCl2
Ca/CuCl2
Li/CuCl2
Fluorides
La/CoF3
Ca/CoF3
Li/FeF3
Li/CuF2
LiC6 / NMC
Volu
metr
icenerg
ydensity
(Wh/l)
Mg
batteries
Metal
Sulphur
Li/S
Mg/S
Metal-
Air
Li/O2
Mg/O2
Na/O2
Zn/O2
Na-ion
Hard-C /
NaNMC
Li Rich FCC materials
Li2VO2F
Li2CrO2F
Evolutionary versus revolutionary materials
Theoretical numbers of electrochemical couples
20DPG Tagung | 6. April 2017
Evolutionary versus revolutionary materials
Gravimetric energy density (Wh/kg)
Li-ion
Ca/CoF3
Chlorides
Mg/CuCl2
Ca/CuCl2
Li/CuCl2
Fluorides
La/CoF3
Ca/CoF3
Li/FeF3
Li/CuF2
Selected battery
concepts
Lithium ion
batteries
Metal sulphur
batteries
Metal oxygen
batteries
Novel battery
chemistries
Liquid metal
batteries
LiC6 / NMC
Volu
metr
icene
rgy
density
(Wh/l)
Mg
batteries
Metal
Sulphur
Li/S
Mg/S
Metal-
Air
Li/O2
Mg/O2
Zn/O2Na/O2
A new way for storing lithium ions
21DPG Tagung | 6. April 2017
Storage on site rather than interstitial storage
Not by classical intercalation, and not by conversion, but by
storage on lattice sites of a cubic cation disordered material.
Paradigm change in storing Li
LiFePO4
Ref. J. Molenda (2011)
„Li rich fcc materials“
R. Chen, M. Fichtner et al., Adv. Energy Mater. (2015)
22DPG Tagung | 6. April 2017
Neutron diffraction pattern (FRM-II, Garching)
Li sensitive
Structure of Li2VO2F
Li2VO2F
66% of cation sites occupied by Li
When Li+ ions are extracted from the lattice, a Li-vacancy reordering may occur to relieve
the electrostatic repulsion, and to minimize the delithiation-induced lattice strain and
volume change.
23DPG Tagung | 6. April 2017
Ionic conductivity of Li2VO2F
Arrhenius plot of bulk ac
electrical conductivity of a
Li2VO2F pellet at various
temperatures.
Ea at 25 °C
Li2VO2F: 185 meV
LiFePO4: 600 meV
24DPG Tagung | 6. April 2017
The Energy Loss Near Edge Structure Upon Charging
ELNES of V L 2,3 and O K-edges of pristine Li2VO2 F and
sample charged to 4.1 V.
Well separated V L3 (518 eV) and
L2 -edges (524.2 eV) owing to the
V 2p–3d dipole transition.
Upon charging to 4.1 V:
V L-edges shift by about 1 eV to
higher energy loss (with a
maximum of 519 eV for the V L3 -
edge, typical for V5+.
(ref.: J. G. Chen et al., Surf. Sci. 1994 , 321 ,
145)
V3+ V5+
25DPG Tagung | 6. April 2017
Cycling of full cell
Stable slope; no voltage fading
1 M LiPF6 in EC/DMC (1:1) electrolyte
based on cathode weight
R. Chen et al., Adv. Energy Mater. (2015)
26DPG Tagung | 6. April 2017
Evolutionary versus revolutionary materials
Gravimetric energy density (Wh/kg)
Li-ion
Ca/CoF3
Chlorides
Mg/CuCl2
Ca/CuCl2
Li/CuCl2
Fluorides
La/CoF3
Ca/CoF3
Li/FeF3
Li/CuF2
Selected battery
concepts
Lithium ion
batteries
Metal sulphur
batteries
Metal oxygen
batteries
Novel battery
chemistries
Liquid metal
batteries
LiC6 / NMC
Volu
metr
icene
rgy
density
(Wh/l)
Mg
batteries
Metal
Sulphur
Li/S
Mg/S
Metal-
Air
Li/O2
Mg/O2
Zn/O2Na/O2
Post Li ion and post-Li systems
27DPG Tagung | 6. April 2017
Motivation / Energy Density, Abundance
No dendritesDendrite formation
LiC6
28DPG Tagung | 6. April 2017
(ref. Avicenne Energy Studies, 2016)
Cathode (currently NMC: NixMnyCozO2)
Cobalt • expensive
• co-mined with Ni
• children labour
• Co resources+reserves last for 85 Mio. battery cars
Active materials in cathodes, worldwide market
Strong increase in LIB production expected
Reality overhauls predictions
Motivation / Element supply
Anode:
Cell needs 100 – 160 g Li / kWh
Germany: 40 Mio cars running on LIB will consume 15 x the current worldwide Li
production. On the long run: will there be a cost-effective recycling?
29DPG Tagung | 6. April 2017
Evolutionary versus revolutionary materials
Gravimetric energy density (Wh/kg)
Li-ion
Ca/CoF3
Chlorides
Mg/CuCl2
Ca/CuCl2
Li/CuCl2
Fluorides
La/CoF3
Ca/CoF3
Li/FeF3
Li/CuF2
Selected battery
concepts
Lithium ion
batteries
Metal sulphur
batteries
Metal oxygen
batteries
Novel battery
chemistries
Liquid metal
batteries
LiC6 / NMC
Volu
metr
icene
rgy
density
(Wh/l)
Mg
batteries
Metal
Sulphur
Li/S
Mg/S
Metal-
Air
Li/O2
Mg/O2
Zn/O2Na/O2
Replace cathode and anode:
Mg sulfur batteries
30DPG Tagung | 6. April 2017
Chloride Ion Batteries
VOCl as cathode
P. Gao, M. Fichtner et al., Angew. Chemie Int. Ed. 53 (2016) 4285
0 30 60 90 120 150 180
1,2
1,6
2,0
2,4
2,8
1st10th
Volta
ge / V
Capacity (mAh/g)
@ 0.5 C rate
0 10 20 30 40 50
30
60
90
120
150
180
2 C0.5 C1 C
1 C0.5 C
Ca
pa
city (
mA
h/g
)
Cycle number
The theoretical capacity is 261 mAh g-1 based on 1 mol e-
transfer;
< 0.7 e- should be kept in practice to avoid structural
collapse
Rate performance
0.5 mol PP14Cl in PC as electrolyte
Mixed intercalation and conversion mechanism
stable in air
31DPG Tagung | 6. April 2017
Mg2+
e-
e-
Anode Cathode
discharge
charge
Mg
Mg offers good handling and operational safety.
No dendrite formation with Mg metal as anode major safety issue with Li metal batteries.
Mg is naturally 1000x more abundant on earth than Li.
Mg/S offers theoretical 3200 Wh/L compared to theoretical 2800 Wh/L for Li/S
But: Sulfur cathode needs non-nucleophilic electrolyte for Mg!
Properties of Magnesium and Lithium
Li Mg
Atomic weight 6.9 24.3
Ionic radius 90 pm 86 pm
Ionic charge + 1 + 2
Reduction potential - 3.04 V - 2.37 V
Density 0.53 g/cm3 1.74 g/cm3
Gravimetric capacity3861 mAh/g (Li)
372 mAh/g (LiC6)2205 mAh/g
Volumetric capacity 2061 mAh/cm3 3832 mAh/cm3
32DPG Tagung | 6. April 2017
First
Electrolytes,
Grignard-based
Electrolytes:
Lewis acid-base complexes
Mg2Cl3+ [A]-
nucleophilic !
Electrolytes:
Lewis acid-base complexes
Mg2Cl3+ [A]-
non-nucleophilic !
Electrolytes:
Mg-salts with big anions
Mg2+ [A]-
non-nucleophilic
Cl-free
Gregory, 1988
2000
2011
2016
Electrolyte development is key
Sulfur can be easily reduced
and needs non-nucleophilic
electrolyte
33DPG Tagung | 6. April 2017
M. Fichtner et al., EP 2824751A1 (2013)
Zh. Zhao-Karger et al., RSC Advances 3 (2013)
Zh. Zhao-Karger et al., RSC Advances 4 (2014)
Zh. Zhao-Karger et al., Adv. Energy Mater. 5
(2015) 1401155
B.P. Vinayan et al., Nanoscale 8 (2016) 3295
New non-nucleophilic and powerful
electrolyte.
Simple to make from standard materials in
various solvents.
Stable up to 3.9 V
First reversible Mg-S cells
Adv. Energy Mater. (2015)
34DPG Tagung | 6. April 2017
Single crystal XRD
½ [Mg2Cl3][(HMDS)AlCl3] + 3/2 (HMDS)AlCl2
(HMDS)2Mg + 2AlCl3
ORTEP plot of
[Mg2(µ-Cl)3·6THF] [HMDS·AlCl3]·THF
(H atoms are omitted for clarity)
Mg2(μ-Cl)3·6THF]+·THF [HMDS AlCl3]-
Mg dichloro-complex
glymes, THF, IL, DME,….
Features
• non-nucleophilic
• versatility w. solvents
• up to 2 M Mg2+ solutions
• 99% electrolyte efficiency
• stability up to 3.9 V
• used in-situ
Zh. Zhao-Karger, M. Fichtner, et al. RSC Adv. (2013)
Zh. Zhao-Karger, M. Fichtner, et al., Adv. Energy Mater. (2015)
35DPG Tagung | 6. April 2017
A. Manthiram et al., ACS Energy Lett. (2016)
Zh. Zhao-Karger, M. Fichtner, et al.,
Adv. Energy Mater. (2015)
Mg2(μ-Cl)3·6THF]+·THF [HMDS AlCl3]-
Improvement by engineering, e.g. of separator
36DPG Tagung | 6. April 2017
A novel Cl-free electrolyte
Mg[L] / DEG-TEG
• Mg [L] with big boron-based anion, easy to synthesize
• Cl-free salt
• soluble in ethers
• non-nucleophilic
• 3.8 V stability limit
• > 98% efficiency
Zh. Zhao-Karger, E.G. Bardaji M. Fichtner, J. Mater. Chem. A (2017) online
uncoated separator
37DPG Tagung | 6. April 2017
• Improved strategy for calculating redox potentials
Study association energies of Mg-ions with candidate anions in solvents
screening for anion-solvent interactions (avoid stronger interaction reduced kinetics)
Screening of Electrolytes for Mg-Ion Batteries (J. E. Mueller)
+
Z. Zhao-Karger, J. E. Mueller, X. Zhao, O. Fuhr, T. Jacob, M. Fichtner, RSC Adv., 2014, 4, 26924
38DPG Tagung | 6. April 2017
Major issues to be solved
• Kinetic barriers / overpotentials are still too high
• Role of surface layers on Mg?
• Reversibility
• Fate of the sulfur in the system
39DPG Tagung | 6. April 2017
Evolutionary versus revolutionary materials
Gravimetric energy density (Wh/kg)
Li-ion
Ca/CoF3
Chlorides
Mg/CuCl2
Ca/CuCl2
Li/CuCl2
Fluorides
La/CoF3
Ca/CoF3
Li/FeF3
Li/CuF2
Selected battery
concepts
Lithium ion
batteries
Metal sulphur
batteries
Metal oxygen
batteries
Novel battery
chemistries
Liquid metal
batteries
LiC6 / NMC
Volu
metr
icene
rgy
density
(Wh/l)
Mg
batteries
Metal
Sulphur
Li/S
Mg/S
Metal-
Air
Li/O2
Mg/O2
Zn/O2Na/O2
Organic electrodes
40DPG Tagung | 6. April 2017
Organic electrodes
Good theoretical capacity
Structural diversity and flexibility
Tunable properties
Good safety
Low cost
Easy processing
Sustainability and environmental
friendliness
Broad field of applications:
o Li, Na and Mg based batteries
o supercapacitors
o redox flow batteries
o all-organic batteries
Z. Song & H. Zhou, Energy Environ. Sci., 2013, 6, 2280.
41DPG Tagung | 6. April 2017
A new class of highly conjugated porphyrin complex enabling high performance of rechargeable batteries
Porphyrins
N
N N
N
N
NH N
HN
SiSi
N
NH N
HN
BrBr
Si
5%mol Pd(PPh3)4, 5%mol CuI
THF/Et3N
2
yield 52%
yield 80%
THF/CH2Cl2
N
N N
N
SiSi
Cu(OAc)2.2H2O
THF/Et3N
TBAFCuCu
yield 95%
3
1 4
Hemocyanin-derived
(Molluscs, Arthropoda)
4 electron transfer from 16 to 20 𝜋 electrons; OCV vs. Li: 3.0 V
RR
42DPG Tagung | 6. April 2017
Structure: self-assembly of porphyrin
Single crystal data
cation-π-stacking (staircase structure)
P.Gao, M. Fichtner et al., submitted (2017)
3.2 Å interlayer distance
43DPG Tagung | 6. April 2017
CuDEPP, electronic structure
[5,15-Bis(ethynyl)-10,20-diphenylporphinato]copper(II)
18 π aromatic compound
CuDEPP
Small HOMO-LUMO gap allows facile electrons exchange
DFT-B3LYP by
J. Muller, Ch. Jung
CuDEPPCuDEPP2- dimer
44DPG Tagung | 6. April 2017
Working principle
Rechargeable batteries based on porphyrin
CuDEPP
Theoret. capacity: 187 mA h g-1 (four electrons)
Porphyrin works as both electron donor and acceptor
Cu2+ center does not participate
45DPG Tagung | 6. April 2017
100 200 300 400 5000
20
40
60
80
100
Temperature/ (oC)
TG
Heat flowWe
igh
t lo
ss/ (%
)
0
25
50
75
100
125
150
175
He
at flo
w/
(mW
)
TGA-DSC in air
2.0 2.5 3.0 3.5 4.0 4.5-0.02
0.00
0.02
0.04
Cu
rre
nt/
mA
Voltage/ V
1st
2nd
3rd
4th
5th
Thermal stability, electrochemistry
CV of the first 5 cycles
0.1 mV/s
2 reversible features
CuDEPP2+ CuDEPP CuDEPP2-
46DPG Tagung | 6. April 2017
Irreversible feature in 1st cycle
as-prepared electrode after initial cycle
P.Gao, M. Fichtner et al., submitted (2017)
Bedioui, F. et al., Acc. Chem. Res. (1995)
Electropolymerization
IR data
47DPG Tagung | 6. April 2017
Rate performance and cycling
Cell: Li / LiPF6 / CuDEPP
48DPG Tagung | 6. April 2017
Ragone Plot
Power density
measured up to 30
kW/kg
Cell 1: Li/LiPF6/CuDEPP (as cathode)
Cell 2: CuDEPP/PP14TFSI/Graphite (as anode)
P. Gao, Z. Zhao-Karger, M. Fichtner et al.,
WO Application and paper submitted (2017)
49DPG Tagung | 6. April 2017
Physicists ?
■ theoretical modeling on all levels:
- atomistic level: prediction of materials structure, thermodynamics and kinetics
- interfaces under electrochemical working conditions
- transport combined with reaction kinetics on a mesoscale up to micron range
■ Structure-property relationships of new materials
■ Processes at interfaces (very crucial…)
■ Elucidating mechanistic and structural details while the material is operating.
■ ….
Yes, the development of new storage materials is governed by synthetic and
physical chemists
but phycisists can be experts for …
50DPG Tagung | 6. April 2017
The „Sea of Battery Research“
future
Big sea of
paradigmatic
research
Creators of new
paradigms and of
follow-up research
Few frontrunners
unknow
ing
kn
ow
ing
Paradigms in:
- Storage principle
- Materials classes
- Analytics
- Modelling
- …
51DPG Tagung | 6. April 2017
Christian Baur
Bhaghavathi Parambath Vinayan
Christian Bonatto Minella
Tobias Braun
Musa Ali Cambaz
Johann Chable
Christina Danetzki
Ping Gao
Franziska Klein
Xiu-Mei Lin
Helen Maria Joseph
Anji Reddy Munnangi
Maxim Pfeifer
Sebastian Wenzel
Zijian Zhao
Zhirong Zhao-Karger
Maximilian Fichtner
The Group
from KIT:modelling:
J. Mueller
M. Ruben Z. Chen
52DPG Tagung | 6. April 2017
Thank you !
http://www.hiu-batteries.de/de/