060310 - power sources rev 2

Lithium Metal Air

Battery Technology

Owen Crowther, Darshana Bansal,

Arthur Driedger III, Benjamin Meyer,

Michael Morgan, and Mark Salomon

MaxPower, Inc.

Harleysville, PA 19438

[email protected]

Mary Hendrickson

US Army CERDEC

Army Power Division

Fort Monmouth, NJ 07703

MaxPower Inc.

Special Purpose Batteries

1

Primary Li-Air Technology

MaxPower is currently developing a

primary Li-Air battery system for:

• Portable Electronic Devices

• Charger Applications

Current research areas:

• Cathode Structures

• Protected Cathode Membrane

• Protected Anode Membrane

• Electrolyte Solutions

• Prototype Single Cell Development

2

Why Li-Air

Metal-Air and Li-Ion Systems OCVSpecific

Energy

Specific

Capacity

V Wh kg-1

mAh g-1

2Li + 0.5O2 ↔ Li2O

(aprotic organic)2.913 11,248 3,862

Li + 0.5O2 ↔ ½Li2O2

(aprotic organic)2.959 11,425 3,862

2Li + 0.5O2 + H2O ↔ 2LiOH

(aqueous)3.446 5,789 1,681

2Li + 0.5O2 + H2SO4 ↔ Li2SO4 +

H2O

(aqueous)

4.274 1,091 255

2Li + 0.5O2 + HCl ↔ 2LiCl + H2O

(aqueous)4.274 3,142 366

Zn + 0.5O2 ↔ ZnO

(aqueous) 1.65 1,353 820

6C + LiCoO2 ↔ xLiC6 + Li1-xCoO2

(aprotic organic)~4.2 420 139

3

Cell Designs

H2O

O2

H2O

O2

H2O

4

• Cathode Development

• Catalyst

• Electrolyte Additive

• Discharge in Air

• Cell Scale Up

Presentation Topics

5

Generation 1 Cathode

• KJB EC600G demonstrates highest capacity

• Largest pore volume for discharge products

Carbon

Surface

Area

m2g

-1

Particle

Size

nm

Pore

Volume

cm3

g-1

Super P 62 40 ~3.8

Vulcan XC-72 235 30 0.59

Black Pearls 2000 1480

12 2.35

Ketjen Black 300 J 800

40 ~3.3

Ketjen Black 600 J 1415

40 5

Darco G60 853 180 0.95

Calgon PWA 900-

1000 440 0.90

Shawinigan black 70 NA ~4.6

q / mAh g-1

C

0 500 1000 1500 2000 2500

E / V

0

1

2

3

4

commercially available E4A

Black Pearls 2000

Vulcan XC72

Super P

KJB EC300G

KJB EC600G

0.2 mA cm-2

O2

10 cm2

20% PTFE

6

Generation 1 Performance

• 80% KJB EC600G 20% PTFE

• Can fabricate cathode pads > 300 cm2

• Compares favorably to literature

• Relatively high capacities at high rates

• Reproducible

q / mAh g-1

C

0 1000 2000 3000 4000

E / V

0

1

2

3

MaxPower

ECS Trans. 3 (2008) 87

0.2 mA cm-2

O2

i / mA cm-2

0.0 0.5 1.0 1.5 2.0

q / m

Ah g

-1 C

0

1000

2000

3000

4000

O2

1.5 V cutoff

10 cm2

7

Generation 2 Cathode

• 95 – 97.5 % Carbon

• Teflon based binder

• Fabricate large pads

• High Capacity

• Per gram of cathode

• Not including grid

• Extremely Large Spread

• Work is ongoing

i / mA cm-2

0.0 0.5 1.0 1.5 2.0 2.5

q /

mA

h g

-1 c

ath

od

e

0

2500

5000

750080% KJB

95% KJB

O2

1.5 V cutoff

10 cm2

135 cm2

95% KJB EC600G

8

MnO2

Catalyst

• Known to increase

capacity

[Angew. Chem. , Int. Ed. 147 (2008) 4521]

• Capacity increased by 1.6

on active materials basis

• Vdischarge

= 2.44 V compared

to 2.07 V

• Reproducible > 500 mAh g-1

• Not Optimized

543 mAh g-1

at 1 mA cm-2

9

MaxPower Electrolyte Additive

Cell Type

i q V avg

mA cm-2

mAh g-1

cathodeV

baseline 0.2 1802.4 2.61

baseline +

catalyst0.2 1970.7 3.16

baseline +

catalyst0.2 1785.5 3.16

baseline 1 248.4 2.43

baseline +

catalyst1 390.3 2.59

• Increase of 0.65 V for

large portion of

discharge at 0.2 mA cm-2

• PATENT PENDING

q / mAh g-1

cathode

0 500 1000 1500 2000

E / V

0

1

2

3

4

standard electrolyte

standard electrolyte + additive

0.2 mA cm-2

O2

q / mAh g-1

cathode

0 100 200 300 400

E / V

0

1

2

3

4

standard electrolyte

standard electrolyte + additive

1 mA cm-2

O2

10

Cathode Membrane Technology

• Hydrophobic membrane that allows

O2

from air into cell and blocks H2O

• Stops evaporation of volatile

electrolyte solvents – DMC, DME, etc

• Various Materials

• Polysiloxanes – High O2

solubility and diffusivity

• Combined with alkyl methacrylates

• Similar to contact lense materials

• Perflourocarbons

• High O2

solubility but difficult to work with

• Perfluorinated polyethers – such as Krytox

• PATENT PENDING

11

Cathode Membrane Processing

Process

Development

Free Standing

Films

Supported

Films

Tape

CastSmearingBellcore Tape

CastSpraying

Plugged

Pores

Smearing Spraying

Key:

Processing Failure

Processing worked but no permeation testing

Processing worked and permeation testing

Not tried yet

Pouring Spin

CoatingPouring

Hot-

Pressing

12

Cell Discharge in Wet Air

• Silicone membrane

• 19000 g O2∙mm∙m

-2∙day

-1

• 50 cm2

for 2A discharge

• Increased capacity

• Lower Vdischarge

• Lithium is in much better

condition

q / mAh g-1

C

0 500 1000 1500 2000

E / V

0

1

2

3porex control

silicone 6-7 mil

silicone 7 mil

tested in air ~ 35% RH

0.2 mA cm-2

13

Coated Cathode

• Thinner membrane on cathode

• Increased capacity at same Vdischarge

q / mAh g-1

C

0 100 200 300 400 500 600

E / V

0

1

2

3

porex control

3-3.5 mil silicone coated on cathode

42.9% RH

0.2 mA cm-2

14

100 cm2

fixtured cell

in air from 10 cm2

pouch cell in O2

Scale Up

10 100 cm2

15

100 cm2

Test Fixture

• 100 cm2

cathodes

• Reproducibility

• Same cell volume

• No heat sealing

• Decreased

electrolyte

• Vacuum filling

16

100 cm2

Cathode Discharge

• 1st

Attempt to Scale to Larger Format

• 100 cm2

cathode retains 90% of small

format pouch capacity

• Voltage drop all iR

q / mAh g-1

C

0 500 1000 1500 2000 2500 3000

E / V

0

1

2

3

4

10 cm2 pouch

100 cm2 fixture

0.2 mA cm-2

O2

17

Conclusions

As a program we are integrating

advances in technology into practical

hardware to develop a primary Li-air

battery with an energy density

greater than 700 Wh kg-1

We are currently researching:

• Component Technology

• Prototype Development

• We would like to acknowledge the

US Army for funding this research

and development under contract

W15P7T-09-C-S33018

060310 - power sources rev 2

Documents