high energy manportable battery€¦ · charge and discharge-20 oc c/10 charge to 4.3v (no clamp)...

High Energy Manportable Battery

Owen Crowther, Hyun Joo Bang, Felix Nunez, Mario Destephen

August 26, 2015

This document does not contain ITAR controlled technical data.

2

Copyright© 2015 EaglePicher Technologies, LLC

Background

• Improving the energy of Li-ion cells desirable for many

applications including personal power, transportation, etc.

• COTS cells with carbon based anode and typical metal

oxide cathode currently deliver 200-240 Wh kg−1

• EPT pouch cells with carbon or silicon-carbon anode and

high nickel cathodes deliver 220-300 Wh kg−1

0 25 50 75 100 125 150 175 200 225 250 275 3000.00

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

1C

C/5

cell

pote

ntia

l diff

ere

nce

/ V

cell specific energy / Wh kg-1

EaglePicher High Energy Pouch

Commercial Energy Cell


3


Outline

• 1.75 Ah pouch for conformable wearable battery

– Requirements

– Initial cell performance

– Cell performance at various temperatures

– Cell safety report

– Battery performance

• Improving energy density

– Incorporation of Si-C composite anode

– Improving specific capacity of cathode material


4


CWB-R battery requirements

• High energy rechargeable battery to reduce Soldier's burden

• Flexible to conform to Soldier’s body armor

17.2V in

recent RFQ


5


CWB-R cell and battery specs

Specification

Cell nominal capacity 1.75 Ah

Cell dimension 50 mm (W) x 57 mm (H) x 6.5 mm (T)

Cell average voltage 3.65 V

Cell max. voltage 4.3 V

Cell weight ~32 g

Cell numbers in a battery 24 cells (6s4p)

Battery capacity >10.5 Ah

Battery energy >150 Wh

Voltage range 10.0 V – 17.2 V

Battery dimension Within the required dimension

Cell performance Design target Test value Requirement

Capacity @ C/5 >1.79 Ah >1.75 Ah >1.75Ah

Capacity @ C/2 >1.61 Ah ~1.72 Ah >1.60 Ah

Cell Energy @ C/5 > 6.4 Wh ~6.4 Wh >6.25 Wh

Cell Energy after 224 cycles > 5.5Wh 5-5.5 Wh >5 Wh

Battery energy @ C/5 >150 Wh >150 Wh >148 Wh

Battery energy after 224

cycles @ C/2 >130 Wh Under test >120 Wh


6


Initial CWB-R cell performance

• Meets performance, cycling, and weight design requirements


0 50 100 150 200 2500.0

4.5

5.0

5.5

6.0

6.5

7.0

0

108

120

132

144

156

168

C/2 discharge

30g cell mass

pro

ject

ed b

attery

energ

y / W

h

cell

energ

y / W

hcycle

0 5 10 15 200.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

4.3V charge4.2V charge

C/51CC/2C/5

C/10C/20

cell

energ

y / W

h

cycle

7


Discharge curves

0.0 0.5 1.0 1.5 2.00.00

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

CWB-R pouch

C/5 discharge

ce

ll vo

lta

ge

/ V

discharge capacity / Ah

-20oC

0oC

10oC

21oC

40oC

55oC

0.0 0.5 1.0 1.5 2.00.00

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

CWB-R pouch

C/2 discharge

ce

ll vo

lta

ge

/ V


-20oC

0oC

10oC

21oC

40oC

55oC

• Cells deliver good capacity from -20 to 55 ºC


8


Temperature effects

-20 -10 0 10 20 30 40 50 600

25

50

75

100 21 oC charge

CWB-R pouch cell

capa

city

nor

mal

ized

by

C/5

RT

cap

acity

/ %

charge and discharge temperature / oC

C/5

C/2

1C

-20 -10 0 10 20 30 40 50 600.0

2.50

2.75

3.00

3.25

3.50

3.75

4.00

21 oC charge

CWB-R pouch cell

ave

rage d

isch

arg

e v

olta

ge / V

charge and discharge temperature / oC

C/5

C/2

1C

• Retention >80% for C/5 rate across the temperature range

• Minimal temperature effect on discharge voltage for ≥0ºC


9


Low temperature charging capability

0.0 0.5 1.0 1.5 2.00.00

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

C/5 discharge at -20 oC

ce

ll vo

lta

ge

/ V

delivered capacity / Ah

C/5 charge at 21 oC with clamp

C/10 charge at -20 oC without clamp


10


Low temperature cycling capability

0.00 0.25 0.50 0.75 1.00 1.25 1.500.0

2.0

2.5

3.0

3.5

4.0

4.50.0 14.9 29.8 44.6 59.5 74.4 89.3

delivers 43% of

nominal energy

at -20 oC

charge and discharge

-20 oC

C/10 charge to 4.3V (no clamp)

C/5 discharge

projected battery energy / Wh

cell

volta

ge /

V


cycle 1

cycle 2

cycle 3

cycle 4

cycle 5


11


0 2 4 6 8 10 12 14 16

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

cell

volta

ge / V

time / hour

0

25

50

75

100

100% SOC

thermocouple on nail

no smoke or fire

tem

pera

ture

/

oC

Nail penetration results


12


UN testing

• CWB-R pouch cells pass UN testing (10 cells each test)

• Battery level UN test planned

Cell level UN tests

T1 altitude pass

T2 thermal pass

T3 vibration pass

T4 shock pass

T5 external short pass

T6 crush pass

T8 forced discharge pass

0.0 0.5 1.0 1.5 2.0

-4

-3

-2

-1

0

1

2

3

4

voltage

temperature

tem

pera

ture

/

oC

T8 - forced discharge test

typical cell

no adverse event

cell

volta

ge / V

discharge time / hours

0

20

25

30

35

40

45

50

55

UN T2 Thermal Test

cell # OCV before

thermal cycles / V OCV after thermal

cycles / V retention

1 4.19 4.17 99.5%

2 4.20 4.14 98.6%

3 4.20 4.14 98.6%

4 4.20 4.14 98.6%

5 4.21 4.14 98.3%

6 4.21 4.14 98.3%

7 4.21 4.14 98.3%

8 4.21 4.14 98.3%

9 4.22 4.15 98.3%

10 4.22 4.15 98.3%

no leakage, mass loss, venting, rupture, disassembly, or fire observed


13


CWB-R battery

wired cells with BMS finished battery in flexible case


14


CWB-R battery performance

0 2 4 6 8 10 120.0

7.5

10.0

12.5

15.0

17.5

160.4 Wh

152.3 Wh

EPT CWB-R battery

10.5Ah rated capacity

~1.1 kg

battery

volta

ge / V


C/5 2.10A

C/2 5.25A


15


Next Generation Li-ion Chemistry


16


Si-C anode background

• Si theoretically 10x specific capacity of conventional carbons

• Higher specific capacity allows for lighter anodes and cells

• EPT licensed OneD Si-C composite anode (formerly

Nanosys) manufacturing technology in 4Q 2014

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.50.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

higher loading

half (coin) cells

cell voltage

ele

ctro

de p

ote

ntia

l / V

vs.

Li

total capacity / mAh

0% Si 340 mAh g-1

4% Si 485 mAh g-1

8% Si 630 mAh g-1


17


Effect of Si content on discharge

0 1 2 3 4 5 6 70.00

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.500 24 48 72 96 120 144 168

lighter cell

C/5 discharge


cell

volta

ge / V

cell energy / Wh

0% Si

4% Si

8% Si

0 1 2 3 4 5 6 70.00

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.500 24 48 72 96 120 144 168

lighter cell

C/2 discharge


cell

volta

ge / V

cell energy / Wh

0% Si

4% Si

8% Si

• Differences in energy caused by difference in the

deintercalation profile of anodes


18


Effect of Si content on cell energy

• Specific energy plateaus at 4% Si for 2Ah pouch

0 2 4 6 8 100

150

175

200

225

250

EPT 2 Ah pouch

cell

speci

fic e

nerg

y / W

h k

g-1

anode Si content / %

C/5

C/2

1/C


19


Effect of Si content on cycling

• Collaboration with binder suppliers to improve cycleability

0 25 50 75 1000

25

50

75

100

125

150

175

200

225

250

decreased cell weight

C/2 discharge

speci

fic e

nerg

y / W

h k

g-1

cycles after grading

0% Si

4% Si

8% Si


20


0 25 50 75 100 125 1500.0

4.0

4.5

5.0

5.5

6.0

6.5

7.0

0

96

108

120

132

144

156

168

inreased cathode Ni content

C/3 charge to 4.3V (125 mA clamp)

C/2 discharge

carbon anode

pro

ject

ed b

attery

energ

y / W

h

cell

energ

y / W

h

cycles

current cathode

next generation cathode

High specific capacity cathode


21


Conclusions

• EPT recently developed 1.75 Ah pouch cells with carbon

anode and high energy cathode for the CWB-R battery

• Cell passed nail penetration and UN tests

• Battery delivers energy >150 Wh at ~1.1 kg weight

• Cell/battery specific energy will be improved further

through incorporation of Si-C composite anode and

improving specific capacity of the cathode

• 10 Ah class pouch also being developed that will deliver

>250 Wh kg−1 at rates ≥1C


high energy manportable battery€¦ · charge and discharge-20 oc c/10 charge to 4.3v (no clamp)...

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