California Energy Commission - Public Interest Energy Research Program

Printed Energy Storage DevicesPrinted Energy Storage Devices

Christine C. Ho1, Prof. James W. Evans1 and Prof. Paul K. Wright2

1Material Science and Engineering, University of California Berkeley, Berkeley, CA2Mechanical Engineering, University of California Berkeley, Berkeley, CA

California Energy Commission - Public Interest Energy Research Program

Hybrid Energy Storage 2011 ‐ Active RFID Tag

(1 x 1 cm)Carbon Electrochemical Capacitor

Energy storage

Energy 

TagTag

harvesting

Zinc Polymer Battery High power transmit

Energy reservoir

California Energy Commission - Public Interest Energy Research Program

Microbattery Design

loadelectrons

Generic BatteryOur Zinc Polymer Battery

y g

r

cathodecurrent collector

100μm

anode cathode

separator

nt collector

nt collector

Curren

Curren

anode

Gel acts as separator and electrolytesubmerged in liquid electrolyte

container seals in liquid

California Energy Commission - Public Interest Energy Research Program

l tGel Electrolyte

electrons

Zinc anode‐

Zn2+ ‐ ‐

‐

Zn2+

load

Gel electrolyte

‐‐

‐

‐‐Zn2+

Zn2+

MnO2 cathode

current collector

75% polymer25% liquid

40% polymer60% liquid

Liquid swells polymer to form gel electrolyte

California Energy Commission - Public Interest Energy Research Program

Fabrication: Dispenser PrintingIntegration of vibration energy harvester with printed capacitor

Dispenser printing:• Capable of 5‐300 μm size factors• Large viscosity range (100‐10000 cP)• Ambient temperature process40 μm

Continuous Printing Drop on Demand

Ambient temperature process• Low waste• Fast, scalable, economical• Continuous assembly processing

40 μm

100 μm dia

California Energy Commission - Public Interest Energy Research Program

Printed Battery

zinc

Microbattery cross‐section

gel electrolyte

20 µmMnO2

Typical discharge potential 

California Energy Commission - Public Interest Energy Research Program

Battery PerformanceCycle capacity

C/5 discharge rate

Current microbattery performance

Capacity Energy Density Operating Voltage

1 mAh/cm2 1.5 mWh/cm2

150 mWh/cm3

130 Wh/kg

1 ‐2 V

California Energy Commission - Public Interest Energy Research Program

Hybrid Energy Storage 2011 ‐ Active RFID Tag

(1 x 1 cm)Carbon Electrochemical Capacitor

Energy storage

Energy 

TagTag

harvesting

Zinc Polymer Battery High power transmit

Energy reservoir

California Energy Commission - Public Interest Energy Research Program

Printed electrochemical capacitors

carbon electrodeb l d

gel electrolyte

gel electrolyte

carbon electrode

carbon electrode carbon electrode

Printed capacitor

California Energy Commission - Public Interest Energy Research Program

Capacitor performancePrinted capacitor cross‐section

carbon electrodeCycle Capacitance Performance

gel electrolyte Steady cycle performance

carbon electrode

charge discharge

Charge and Discharge Potentials for 1 mA

Current electrochemical capacitor  performance

C it M P E D it O tig g Capacitance Max. Power Energy Density Operating Voltage

100 mF/cm2 600 μW/cm2

60 mW/cm3

50 W/kg

10 μW-hr/cm2

1 mW-hr/cm3

1 W-hr/kg

0 – 2 V

> 93% charge efficiency50 W/kg 1 W-hr/kg

California Energy Commission - Public Interest Energy Research Program

“Printing on Green”Printing on Green

California Energy Commission - Public Interest Energy Research Program

Thin and flexible displaysThin and flexible displays

California Energy Commission - Public Interest Energy Research Program

Printed  Media

California Energy Commission - Public Interest Energy Research Program

Large‐scale energy storageZinc Polymer Battery 

150 mWh/cm3 ~ 2,600 sq. ft

Prefabricated walls

150 mWh/cm , q

1000 kW‐hr stored!+‐

California Energy Commission - Public Interest Energy Research Program

Printed Energy Storage DevicesPrinted Energy Storage Devices

• Fully printed energy storage devices (batteries and electrochemical capacitors) were fabricated

• Direct write dispenser printing is a flexible tool that can be useful for tailoring energy storage devices to provide optimal performance for a given application.

• Implementation and testing of printed energy storage devices is underway

• Acknowledgements: California Energy Commission, Delta Electronics, Berkeley Manufacturing Institute and Berkeley Wireless Research Center, Center for Information Technology Research in the Interest of Societygy y

For more information, contact: christine.c.ho@berkeley.edu

California Energy Commission - Public Interest Energy Research Program

California Energy Commission - Public Interest Energy Research Program

~ 2,600 sq. ft

2‐15kW

Average homes:20kWh/d

ay +‐

< 5% walls filled with printed battery

California Energy Commission - Public Interest Energy Research Program

CostsA square meter of printed battery stores 15 Wh

Costs

Component $/sq. meter

Zinc 0.65

M O 0 26MnO2 0.26

Organics 0.20

Collector/substrate 0.10

Printing 0.20

TOTAL $1.51 = $101/kWhNewsprint costs ~ $0.05/sq. meter

California Energy Commission - Public Interest Energy Research Program

Printed battery

http://www.electricitystorage.org/site/technologies/

California Energy Commission - Public Interest Energy Research Program

100

Device leakage with respect to cell voltageStorage capacity as a function of discharge current

60708090

disc

harg

e ty

20304050

f max

imum

ca

paci

t

01020

0.001 0.01 0.1 1 10

% o

f

current density (mA/cm^2)