© Dow 2010 All rights reserved June 2010
Advanced materialselection for Li-ion
Dow Chemical
© Dow 2010 All rights reserved June 2010
COSTSAFETY
LIFE
Industry demands the performance of Li-ion
Material barriers preventLi-ion enabling industrial apps
BUTLi-ion dominates consumer
portable applications
MaterialBarrier
Consumer Apps Industrial Applications
New materials are essential to bring the benefits of Li-ionto industrial and Automotive applications
“To make a leap forwards with hybrids,we’ll need a new battery technology”.
- D. Hermance, Toyota .
1-3 3-5 20-50 50-90 30-100 100-300 250-1000 2000
Wh (capacity)
Phone PDA LaptopPowertools eBike UPS HEVMedic pHEV
15000
© Dow 2010 All rights reserved June 2010
Dow applies unique competences to enableLithium Ion batteries and applications
ManufacturingPolymer films (packaging)
FilmTec membranes (water purification)World-class cellulose ethersLargest global latex supplier
High purity solventsSix-Sigma
ChemistryInorganic chemistryOrganic ChemistrySB latex chemistry
Cellulose ether-based materialsSmall molecule synthesis
Electrochemistry
Dow is a leading automotive supplier and provides capability andcredibility in building Li-ion business for P-H-EV
Material SciencePolymer film technologyPolymer material science
Polymer processing /rheologyHigh through-put R&D
Transport scienceModeling
© Dow 2010 All rights reserved June 2010
Dow’s Objective: to enable Li-Ion applications
• Apply Dow’s long history of materials innovation into emerging
automotive P-H-EV and other Lithium-ion applicationsincluding power tools and e-bike
• Develop advantaged materials, that create value for ourpartners & customers
• Develop strategic mutually beneficial partnerships to developnext generation Li-ion components
• Provide unparallel service and support to our customers andpartners that enables them to capture significant market share
The Dow Chemical Company seeks to become apreferred supplier of superior materials to
lithium-ion battery manufacturers
© Dow 2010 All rights reserved June 2010
Dow’s Developmental Separator:High Thermal Dimensional Stability
Early stage developmental separator
• Minimal shrink after aging 1hr at 225ºC• excellent thermal dimensional stability vs polyolefin separators
Dow Separator225ºC for 1 hour
(no shrink at 125ºC)
Before
After
© Dow 2010 All rights reserved June 2010
Dow Electrolyte A – Developmental ProductDow is developing differentiated carbonate-based electrolyte using
novel additives that will lead to improved safety through lower flammability
Electrolyte PropertiesCarbonateBaseline
DowElectrolyte A
Decomposition Temp.
(Safety)180 ºC ~240 ºC
Conductivity (@25 °C)
(Power/Energy Density)10 mS/ cm 9 mS/ cm
Oxidative Stability
(High V. Cathodes)4.5 V 4.5 V
Temperature Range
(Operating capability)-20 to +50 ºC -20 to +50 ºC
• Increased decomposition temperature (~ 60ºC higher)
• Excellent performance (results indicate increased capacity)
• R&D efforts to further increase conductivity and temperature range
© Dow 2010 All rights reserved June 2010
Dow Electrolyte A improves
thermal stability
•Enables safer batteries
•Thermal decompositiontemperature increased
•Heat flow significantly reduced =lower heat generation duringthermal decomposition
Dow Electrolyte A demonstrates
improved performance (button cell)
• Increased capacity (~25% increaseat 3V) vs carbonate controlwithout additive
• Validation is in progress
(large format cells)
4C Discharge Curves
1M LiPF6 in EC/DEC 1:1 v/v
2
2.5
3
3.5
4
4.5
0 20 40 60 80 100
Specific Capacity (mAh/g)
Vo
ltag
e(V
)
Carbonate Control
Dow Electrolyte A
Thermal Stability Comparison
Control: 1M LiPF6 in 1:1 EC/DEC
-1
0
1
2
0 50 100 150 200 250 300
Temperature (C)
Heat
Flo
w(W
/g)
Carbonate control
Dow Electrolyte A
Electrolyte A: Performance Data
© Dow 2010 All rights reserved June 2010
Dow’s Commercially Available Binders:SBR Latex & CMC (Carboxy Methyl Cellulose)
Degree of Substitution (d.s.) = 1
Dow is the only company offering both Latex and Cellulose Ethers
• Ideal for nano structured anodes
• Water based processing
© Dow 2010 All rights reserved June 2010 9
2003 2005 2006 200920082007
R&DPatents
Up scale
Full cell
Demoapps
First demonstrator cells Proven in 100 kg scale
Dow cathode story: from Nano to MacroFrom Idea to Application
© Dow 2010 All rights reserved June 2010 10
A new cathode: Why Phosphate ?Advantage of phosphates:• Low cost• Over-charge & under-charge resilient (1 Li)• Excellent structural stability (strong bond P-O)
- Good cycle life- Thermally and chemically stable- Safe
Phosphate choice:• Iron too low V 3.6 V vs. Li• Cobalt too high V 4.8 V vs. Li• Nickel too high V 5.1 V vs. Li• Manganese ideal V 4.1 V vs. Li
DOW combine benefits of a Phosphate and voltage of an Oxide
PLi
Mn
Durable Power Safe, V, low cost ($/kg)
High EnergyLow cost ($/Wh)
Nanostructured Li Mn PO4 =
© Dow 2010 All rights reserved June 2010 11
Challenges of Phosphates, LiMnPO4
2.5 3.0 3.5 4.0 4.5-0.0003
-0.0002
-0.0001
0.0000
0.0001
0.0002
0.0003
3.48 V
3.6 V
3.9 V
4.22 V
I/A
cm
-2)
E / V vs. Li/Li+
Scan rate 25 V s-1
Temp. = 30oC
• LiMnPO4 is even less conductive than LiFePO4 : more polarisation- Carbon coating technology is more critical
• LiMnPO4 has double lattice mismatch than LiFePO4- Smaller domain and particle size necessary
• Low material density for phosphates: LiCoO2: 5.5, LiFePO4: 3.7, LiMnPO4: 3.4 g/cm3
• Sensitivity of Fe to air and moisture
• Sensitivity of anode to Fe and Mn
Challenge: electronic conductivity *
* C. Delacourt et al. Solid state ionics 117 (2006) 333C. Delacourt et al. J. Electrochem. Soc 152 (2005) A913
Challenge: Impedance
Phosphates have low density, and conductivity:Mn Phosphate is even more challenging!
© Dow 2010 All rights reserved June 2010 12
LiMnPO4 electrochemical performance
Charge C+CV – Discharge C/10
Dow show world best performance and stability for LiMnPO4
Performance
Charging condition: CCCV 2.7 - 4.4V vs. LiDischarge: C rate calculated from 150mAh/gElectrode: C-LiMnPO4 2% carbon, 7.5% PVDF
Total carbon in electrode 20%Electrode thickness: 53 micronLoading (AM): 5.42 mg/cm2
Electrolyte: 1 M LiPF6 EC / PC / DMC 1:1:3 w/wRoom Temperature 0
20
40
60
80
100
120
140
160
0 1 2 3 4 5C-rate
Spe
cific
capa
city
(mA
h/g)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
Dis
char
geen
ergy
(Wh/
g)
Before durability
After durability
200 cycles at 50oC
© Dow 2010 All rights reserved June 2010 13
Electrode preparation, Cell preparation
Slurry Coating Calendar
Real electrode with good mechanical properties and performance
Cell
60 - 90 µm ~ 8-10 mg/cm2
150 mAh/g ~ 1.5 mAh/cm2
Standard electrolyte
Good adhesion Poor adhesion
© Dow 2010 All rights reserved June 2010 14
0
50
100
150
0 100 200 300 400 500 600Cycle number
Spe
cific
capa
city
(mA
h.g-
1)
0
50
100
150
Effi
cien
cy(%
)
0
50
100
150
0 50 100 150 200 250 300Cycle number
Spe
cific
capa
city
(mA
h.g-
1)
0
50
100
150
Effi
cien
cy(%
)5 D
Performance & durability of DOW G2 materialDurability at Room T
Charging condition: CCCV 2.7 - 4.25V vs. LiDischarge: C rate calculated from 150mAh/gElectrode: C-LiFe0.2Mn0.8PO4, 2% Carbon, 5% PVDF
Total carbon in electrode 10%Electrode thickness: 41 micronLoading (AM): 5.4 mg/cm2
Electrolyte: LP30 + 1% VC
Durability at 50 C
Impressive performance and stability for DOW material
D/10
1D
0
20
40
60
80
100
120
140
160
180
0 1 2 3 4 5C-rate
Spe
cific
capa
city
(mA
h/g)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Dis
char
geen
ergy
(Wh/
g)
50 C
RT
Performance
© Dow 2010 All rights reserved June 2010 15
DOW G2 material
0 2 4 6 8 10
50
100
150
200
Dis
charg
ecapacit
y(m
Ah/g)
Rates of discharge
C C C C C
LiNi0.5
Mn0.5
O2
LiNi0.33
Mn0.33
Co0.33
O2
LiNi0.4
Mn0.4
Co0.2
O2
LiNi0.8
Co0.15
Al0.05
O2
Dow performance: Bar-Ilan University
Dow rate performance exceeds alternatives
© Dow 2010 All rights reserved June 2010 16
DOW stability at 50 oC : Bar-Ilan University
Bar-Ilan University confirm good stability
Dow’s“LiMnPO4 is the least surface reactive of all cathode materials studied;this is well expressed in very good cycleability.It’s rate capability is better than NCA and NMO”
Prof Aurbach, IMLB 2008, China
Cycle number
© Dow 2010 All rights reserved June 2010 17
XANES measurements of DOW LiMnPO4
0
0,4
0,8
1,2
1,6
6540 6560 6580 6600 6620 6640
merge_021_d1_cartomerge_021_C0_2pos1merge_021_C0_2pos2merge_021_C0_4pos1merge_021_C0_4pos2merge_021_CO_6pos1merge_021_C0_6pos2merge_021_C0_8pos1merge_021_C0_8pos2merge_021_C1pos1merge_021_C1pos2
energy
MnPO4
LiMnPO4
0
0,4
0,8
1,2
1,6
6540 6560 6580 6600 6620 6640
merge_021_d1_cartomerge_021_C0_2pos1merge_021_C0_2pos2merge_021_C0_4pos1merge_021_C0_4pos2merge_021_CO_6pos1merge_021_C0_6pos2merge_021_C0_8pos1merge_021_C0_8pos2merge_021_C1pos1merge_021_C1pos2
energy
MnPO4
LiMnPO4
Displacement in lower energies:reduction of Mn (Mn3+ Mn2+)
DischargingCharging
0
0,4
0,8
1,2
1,6
6540 6560 6580 6600 6620 6640
merge_021_D0_2
merge_021_d0_4_carto
merge_021_D0_6
merge_021_D08
merge_021_d1_carto
merge_022PX3
energy
Li0.2MnPO4
LiMnPO4
Isobestic points
0
0,4
0,8
1,2
1,6
6540 6560 6580 6600 6620 6640
merge_021_D0_2
merge_021_d0_4_carto
merge_021_D0_6
merge_021_D08
merge_021_d1_carto
merge_022PX3
energy
Li0.2MnPO4
LiMnPO4
0
0,4
0,8
1,2
1,6
6540 6560 6580 6600 6620 6640
merge_021_D0_2
merge_021_d0_4_carto
merge_021_D0_6
merge_021_D08
merge_021_d1_carto
merge_022PX3
energy
Li0.2MnPO4
LiMnPO4
Isobestic points
Displacement in higher energies:oxidation of Mn (Mn2+ Mn3+)
• Both LiMnPO4 and MnPO4 phases are present during the charge and dischargeIsobestic points indicate a linear combination of each species
• No pre-peak change during charge/discharge – no perturbation on Mn octaedric site
• No Jahn-Teller effect (in contrast to MnO2 )
No structural re-arrangement : this explains the excellent durability
Tested at INM (Fr) PSI (Ch)
© Dow 2010 All rights reserved June 2010 18
Dow performance 18650 prototype cell
Capacity at 1C: 900 mAhCycle: 4.25-2.0VCharge CCCV: CC 2 C/2
CV at 4.25 V until C/100
0 3 6 9 12 15 18 21 24
0
20
40
60
80
1000.5C
HPL- 18650 cell-5Gen 2.1 - LMPOV range: 4.25 ~2V
1C10C8C5C
2C
Ca
pa
city
rete
ntion
(%)
Cycle No.
1C
© Dow 2010 All rights reserved June 2010 19
overcharge test 18650 cell with DOW cathode:
Voltage
Temperature
Voltage
Temperature
No smoke, no leakage and no explosionDow cathode is at the centre of a safe cell
Tested at Bar Ilan
© Dow 2010 All rights reserved June 2010 20
Validation of safety: DSC parallel exp.
LiMnPO4 is safer than alternatives (similar to Iron Phosphate)
Tested at Bar Ilan
© Dow 2010 All rights reserved June 2010 21
0
20
40
60
80
100
120
140
0 5 10 15Cycle number
Spe
cific
capa
city
(cat
hode
)[m
Ah/
g]
D/10 D/5 D/2 D 2D
1.7
1.9
2.1
2.3
2.5
2.7
2.9
0 10 20 30Time [hour]
Cel
lVol
tage
-6.00
-3.00
0.00
3.00
6.00
Cur
rent
[mA
]
Voltage
Current
100
125
150
0 50 100 150 200 250 300Cyclenumber
Spe
c.C
apac
ity(c
atho
de)
[mA
h/g] Cycle life at room T
D/2, C/5
Charge C/10– Discharge C/10Discharge capacity (C/5 charge)
Novel, safe, durable Li-ion : Li4Ti5O12-LiMnPO4
Li Titanate - Mn Phosphate: a safe, durable 2.5V power source
© Dow 2010 All rights reserved June 2010 22
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
LiCoO2 LiFePO4 DowP
rice
of
Ind
ustr
ialL
i-Io
n($
/Wh
) Prodution
Other Materials
Cathode Materials
Price breakdown of a 3.6 Ah HEV Li-ion cell
Do not meet requirements:• LiCoO2 Not Safe, Cost• NMC,NCA Not Safe, Cost• LiMn2O4 Poor durability
Industry requirements:– Intrinsically safe– Low cost– Durable
Achieverequirements
LiFePO4
DOW
LiMnPO4
Voltage (vs. C) 3.2 3.85
Implication20% less
cells
Price ($/Wh)20% less
cost
In battery pack
20% more Voltage = 20% less cells in series
= 20% less electronics cost
Performance Li Mn PO4 achieves industry targets
Manganese Phosphate material can solve safety,battery cost, environment issues
© Dow 2010 All rights reserved June 2010 23
Dow is an ideal partnerBreak-through technology
Unique Cathode material - LiMnPO4
Performance
Safe
Durability
Compatible with cell production
Industry cost target
Validated Protected technology
3 year advance in field
DOW technology & team
Numerous patents
Validated in demonstrator cells
Scale up in progress
Winning team
Quality supplier of fine chemical
World class products
Global logistics and support
Strong relations with Automotive
Technical leaders
Energy Storage Solutions
Dow’s history of innovation
Aim: preferred supplier of Li-ion material
Electrolyte high safety & performance
Binder nano-anodes & ecological
Separator high T stability
Dow enable Li-ion industrial applications