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

Transcription

1 Printed Energy Storage Devices Christine C. Ho 1, Prof. James W. Evans 1 and Prof. Paul K. Wright 2 1 Material Science and Engineering, University of California Berkeley, Berkeley, CA 2 Mechanical Engineering, University of California Berkeley, Berkeley, CA

2 Hybrid Energy Storage Tag 2011 Active RFID Tag (1 x1 cm) Tag Energy storage Energy harvesting Carbon Electrochemical Capacitor High power transmit Zinc Polymer Battery Energy reservoir

3 Generic Battery load Microbattery Design electrons Our Zinc Polymer Battery cathode current collector Curren nt collector anode separator cathode Curren nt collector 100 μm anode submerged in liquid electrolyte Gel acts as separator and electrolyte container seals in liquid

4 Zn 2+ Zn 2+ Zn 2+ Gel Electrolyte Zinc anode Gel electrolyte MnO 2 cathode Zn 2+ electrons load current collector Liquid swells polymer to form gel electrolyte 75% polymer 25% liquid 40% polymer 60% liquid

5 Fabrication: Dispenser Printing Integration of vibration energy harvester with printed capacitor Continuous Printing 40 μm Drop on Demand 100 μm dia Dispenser printing: Capable of μmsize factors Large viscosity range ( cp) Ambient temperature process Low waste Fast, scalable, economical Continuous assembly processing

6 Printed Battery Microbattery cross section zinc gel electrolyte MnO 2 20 µm Typical discharge potential

7 Battery Performance Cycle capacity C/5 discharge rate Current microbatteryperformance Capacity Energy Density Operating Voltage 1 mah/cm mwh/cm mwh/cm Wh/kg 1 2 V

8 Hybrid Energy Storage Tag 2011 Active RFID Tag (1 x1 cm) Tag Energy storage Energy harvesting Carbon Electrochemical Capacitor High power transmit Zinc Polymer Battery Energy reservoir

9 Printed electrochemical capacitors carbon electrode gel electrolyte carbon electrode carbon electrode gel electrolyte carbon electrode Printed capacitor

10 Capacitor performance Printed capacitor cross section carbon electrode Cycle Capacitance Performance gel electrolyte Steady cycle performance carbon electrode Charge and Discharge Potentials for 1 ma Current electrochemical capacitor performance charge discharge Capacitance Max. Power Energy Density Operating > 93% charge efficiency Voltage 100 mf/cm μw/cm 2 10 μw-hr/cm V 60 mw/cm 3 1 mw-hr/cm 3 50 W/kg 1 W-hr/kg

11 Printing on Green

12 Thin and flexible displays

13 Printed Media

14 Large scale energy storage Zinc Polymer Battery 150 mwh/cm 3 ~ 2,600 sq. ft Prefabricated walls 1000 kw hr stored! +

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

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17 ~ 2,600 sq. ft 2 15kW Average homes:20kwh/d ay + < 5% walls filled with printed battery

18 Costs A square meter of printed battery stores 15 Wh Newsprint costs ~ $0.05/sq. meter Component Zinc 0.65 MnO Organics 0.20 Collector/substrate 0.10 Printing 0.20 TOTAL $/sq. meter $1.51 = $101/kWh

19 Printed battery

20 Storage capacity as a function of discharge current discharge ty % of maximum capacit Device leakage with respect to cell voltage current density (ma/cm^2)