Printed Energy Storage

Transcription

1 Printed Energy Storage Prof. James W. Evans 1,Jay Keist 1, Christine Ho 1, Ba Quan 1 & 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 System on a Chip Energy Storage Wi l SSensor Wireless Micro device MEMS Sensor Sensor Energy storage Radio Cable Output Voltage Energy harvesting Energy Harvesting Magnetic Field Piezoelectric MEMS Cantilever Radio Microscale Magnet

3 Hybrid Energy Storage Integrated Wireless Sensor Device Energy storage Wireless Sensor Energy harvesting Carbon Electrochemical Capacitor High Areal Power Density Zinc Polymer Battery Large Areal Energy Density

4 Outline Printed zinc microbatteries Pi Printed capacitors Larger scale printed energy storage

5 Batteries With Zinc Electrodes High specific energy and volumetric energy density Lower cost Materials Packaging/Encapsulation i Safety Electrochemical lreversibility bl rgy Density (Wh/k g) Theore etical Ene

6 Fabrication: Dispenser Printing Dispenser printing of multilayer structure Features: Capable of μmsize factors Large viscosity range ( cp) Ambient temperature process Low waste Fast, scalable, economical Continuous assembly processing

7 Zinc based Polymer Cells Zinc/Silver Oxide Chemistry electrons Zinc anode Zinc/MnO 2 Chemistry Zinc anode electrons Alkaline gel electrolyte load Ionic liquid gel electrolyte load Silver oxide cathode MnO 2 cathode current collector current collector Discharge Curve Discharge Curve Storage Capacity Depth of Discharge (mah/cm 2 )

8 The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again. Printed Zn/MnO 2 Microbattery Microbattery cross section Zinc/MnO 2 Chemistry electrons zinc gel electrolyte Zinc anode l l Solid gel electrolyte load Cycle capacity 20 µm MnO 2 MnO 2 cathode current collector CURRENT MICROBATTERY PERFORMANCE C/5 discharge rate Capacity Energy Density Operating Voltage 1 mah/cm mah/cm 3 87 Ah/kg 1.5 mwh/cm mwh/cm Wh/kg 1 2 V

9 Where we left you 6 months ago: Printed Energy Storage Printed Zn MnO 2 batteries demonstrate adequate energy, power and cycle life to warrant further study at larger scale. Zinc anode Ionic liquid gel electrolyte MnO 2 cathode current collector Discharge Curve electrons load Printed capacitors achieve several thousand cycles. Progress made in past 6 months: Christine Ho finishes i Ph.D. dissertation, i and

10 Alkaline Based Solid Electrolyte Electrolyte based on PVA Poly(vinyl Alcohol) Absorbsalkaline electrolytes Exhibits high strength High ionic conductivity High electrochemical stability Battery built by casting or printing PVA based electrode and electrolyte layers Compatible with zinc based battery systems Solid Electrolyte Film 5 mm Electrolyte Film Cross Section

11 Zinc/Silver Battery Performance Microbattery Cross Section Zinc Electrode Zinc/Silver Battery electrons PVA Electrolyte Zinc Anode Cycle capacity PVA AgO AO/A 2 /AgO Electrode Solid Gel Electrolyte load AgO 2 /AgO Cathode current collector Typical discharge potential Depth of Discharge (mah/cm 2 )

12 Zinc/Silver Battery Performance Microbattery Cross Section Zinc Electrode Zinc/Silver Battery electrons PVA Electrolyte Zinc Anode PVA AgO AO/A 2 /AgO Electrode Solid Gel Electrolyte AgO 2 /AgO Cathode load Cycle capacity current collector CURRENT MICROBATTERY PERFORMANCE Capacity Energy Density Operating Voltage 0.8 mah/cm mwh/cm V

13 The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again. Understanding the Zinc Electrolyte Interface Zn 2+ Aqueous Electrolyte Zinc anode Gel electrolyte Cathode electrons load Zinc/electrolyte interface determines cycling behavior Formation of harmful morphologies (e.g. dendrites) Electrode shape change Capacity loss IL Gel Electrolyte

14 Outline Printed zinc microbatteries Pi Printed capacitors Larger scale printed energy storage

15 Hybrid Energy Storage Integrated Wireless Sensor Device Energy storage Wireless Sensor Energy harvesting Carbon Electrochemical Capacitor High Areal Power Density Zinc Polymer Battery Large Areal Energy Density

16 Printed Electrochemical Capactiors gel polymer add active particles mix ink carbon electrode gel electrolyte carbon electrode 16

17 Capacitor performance you saw this before Printed capacitor cross section carbon electrode gel electrolyte Steady cycle performance carbon electrode Charge and Discharge Potentials for 1 ma charge discharge CURRENT ELECTROCHEMICAL CAPACITOR PERFORMANCE > 93% charge efficiency Capacitance Max. Power Energy Density Operating Voltage 10 μw hr/cm V 100 mf/cm μw/cm 2 60 mw/cm 3 1 mw hr/cm 3 50 W/kg 1 W hr/kg

18 Fully Printed Capacitors Bottom Current Collector Ni Coated Carbon Fibers in PVDF Ni Flakes in PVDF Bottom Electrode Electrolyte Top Electrode Top Current Collector Lab Synthesized Ni Epoxy Commercial Inorganic Ni Paste Commercial Ni Epoxy After Electrode Layer Before Electrode Current Collector Sheet Resistance (Ohms)

19 Outline Printed zinc microbatteries Pi Printed capacitors Larger scale printed energy storage

20 Energy storage at the larger scale ~20 kwh scale ~100 MWh scale

21 Energy Storage Association p// / / p / p g

22 Thinking beyond dispenser printing can we print large scale energy storage? Screen printing Flexographic printing Use the chemistry, inks and know how developed at dispenser printer level.

23 Printing cost for 2,200 copies (36 pages including 4 color) = $1,600. Works out at 15.8 cents/sq. meter Add chemicals for battery: Zinc powder = $3.80/kg means 65.0 cents/sq. meter Battery grade MnO 2 = $1.50/kg means 26.0 cents/sq. meter Organics etc about Total 45.0 cents/sq. meter $1.52/sq. meter A sq. meter of the Zn/ionic liquid/mno 2 battery stores 15Wh energy Therefore energy storage capital cost = approx $100/kWh storage capacity

24 Projected capital cost of printed Zn MnO 2 energy storage

25 Printing not just for newspapers, wallpaper and labels; Nanosolar printed solar cells

26 Printed Energy Storage Devices Dispenser printed energy storage devices (batteries and electrochemical capacitors) were fabricated Dispenser printing is a flexible tool that is useful for tailoring energy storage devices to provide optimal performance for a various applications at the 1cm scale Implementation and testing of printed energy storage devices is underway Future work will include research on the zinc/gel electrolyte interface, improving cycle life of batteries and improving performance of capacitors. Large scale printed energy storage a possibility Energy storage Wireless Sensor Energy harvesting