Materials Design for Grid-Scale Energy Storage

Transcription

1 Materials Design for Grid-Scale Energy Storage Yi Cui Department of Materials Science and Engineering Stanford University Stanford Institute for Materials and Energy Sciences SLAC National Accelerator Laboratory Collaborator: Prof. Robert Huggins Students: Colin Wessels, Mauro Pasta, Richard Wang, Hyun-Wook Lee

2 Energy Storage: Enable Renewable Penetration Solar Wind Electric grid - Smooth fluctuations: seconds-to-minutes-to-hours - Peak shifting: hours-to-days

3 Grid Scale Energy Storage Low-cost: - Initial cost: <$100/kWh - Life time cost: <$0.025/kWh cycle Scalable (~MW-GW/plant) to TW Life: Years Cycle life: > 5000 cycles Round trip energy efficiency: >90% Energy density: affecting cost

4 Existing Storage Technologies Are Not Adequate Electricity Energy Storage Technology Options. EPRI, Palo Alto, CA: Pumped hydroelectric power: - Scalable, low-cost, long life. - Location dependent, low energy density, low energy efficiency. 4

5 Existing Electrochemical Energy Storage Too Expensive Not Enough Cycles Not yet scalable: World annual Li-battery production: 40GW for 1 hr. Need 30 years to get to 1TW scale. 1. Electricity Energy Storage Technology Options. EPRI, Palo Alto, CA: Energy Storage for the Electricity Grid: Benefits and Market Potential Assessment Guide. 5 Sandia National Laboratories, Albequerque, NM, and Livermore, CA: SAND Strategic Analysis of Energy Storage in California. California Energy Commission, Sacramento, CA: CEC

6 Battery Basics 1) Low-cost abundant materials - Electrode - Electrolyte - Separators 2) 500 cycles need to go to 50,000 cycles 2) Scalable processing to make batteries (Courtesy of Venkat Srinivasan)

7 Prussian Blue: Open Framework Ferric ferrocyanide hydrate: KFe III Fe II (CN) 6 nh 2 O Channel Through Framework R P 7

8 Open Framework Allows Fast Ion Transport Prussian Blue analogues: Channel radius: R c = 1.6 Å LiCoO 2 : Channel radius: R c = 0.43 Å Crystal Ionic Radius Li Å Na Å K Å Shannon, R. D. Acta Cryst., A32, 751 (1976). 8

9 A Family of Prussian Blue-Like Materials Open Framework Crystal Structure: APR(CN) 6 nh 2 O P and R = Transition Metals, A = Alkali Ions Examples: Prussian Blue: P=Fe 3+ R=Fe 2+ Copper Hexacyanoferrate (CuHCF): P=Cu 2+ R=Fe 3+ R P Nickel Hexacyanoferrate (NiHCF): P=Ni 2+ R=Fe 3+ 9

10 Synthesis of Prussian Blue Analogues Room-temperature aqueous chemical reaction of transition metal salts. Result: spontaneous precipitation of solid product. Example: Prussian Blue K Fe 3 Fe II CN 6 4 KFe III Fe II CN 6 General synthesis: A P 2 R III CN 6 3 APR CN 6 A = K +, Na + P = Fe, Cu, Ni, Co, Mn, Zn R = Fe, Cr, Mn (C. Wessels, R. Huggins, Y. Cui, Nature Communication, 2:550 (2011)) 10

11 Copper Hexacyanoferrate As Ultrafast Positive Electrodes 1 M K + Aqueous Electrolyte: (C. Wessels, R. Huggins, Y. Cui, Nature Communication, 2:550 (2011)) 11

12 Copper Hexacyanoferrate As Ultrafast Positive Electrodes 1 M K + aqueous electrolyte: (C. Wessels, R. Huggins, Y. Cui, Nature Communication, 2:550 (2011)) 12

13 Also Work Well in Na+ Electrolyte

14 Rate Capability of Copper Hexacyanoferrate 7 8 (C. Wessels, R. Huggins, Y. Cui, Nature Communication, 2:550 (2011)) 14

15 Ultralong Cycle Life of Copper Hexacyanoferrate Cycle Life of CuHCF/1 M K + at 17C (Yi Cui Group, Nature Communication, 2:550 (2011)) 15

16 Near Zero Strain: Stable Open Framework CuHCF 400 Peak vs. Charge State 400 CuHCF a 0 vs. Charge State a 0 = 0.1 Å Strain = 0.1% Reason for strain: 2 r Fe-C = 0.1 Å (Yi Cui Group, Nature Communication, 2:550 (2011)) 16

17 Tuning the Voltage: Cu, Ni HCF and Their Solid Solution C. Wessels, R. Huggins, Yi Cui ACS Nano, 6, 1688 (2012).

18 CuHCF Open Framework: Effects of A + ions C. Wessels, R. Huggins, Y. Cui, Journal of The Electrochemical Society, 159 (2) A98- A103 (2012)

19 What About Negative Electrodes? Need negative electrodes with potential ~0V versus H 2 /H +

20 Potential vs. SHE / V What About Hybrid Negative Electrodes? 1.0 (+) CuHCF 0.25 (-) Activate Carbon (AC) (-) PPy/AC time

21 Hybrid Negative Electrodes [K + ]=1M, ph=1, 1 C (+) CuHCF (-) 10% PPy/AC NaBH 4 M. Pasta, R. Huggins, Y. Cui Nat. Comm. (2012), In Press.

22 Open Framework Battery: Full Cell Potential Profile Full Cell (+) CuHCF ([K + ]=1M, ph=1, 10 C) (-) 10%PPy-AC M. Pasta, R. Huggins, Y. Cui Nat. Comm. (2012), In Press.

23 CuHCF- PPy/C Full Battery: Cycle Life ([K + ]=1M, ph=1, 10 C) M. Pasta, R. Huggins, Y. Cui Nat. Comm. (2012), In Press.

24 Open Framework Structure Negative Electrodes Manganese (II) Hexacyanomanganate (III) Mn III C N Mn II Mn(II), P site Mn (I, II, III), R site M. Pasta, Y. Cui (unpublished results)

25 CV Mn II HCMn III, NaClO 4 sat. ph=7, 2 mv/s

26 Mn II N C Mn III/II M. Pasta, Y. Cui (unpublished results)

27 What About Divalent Ion Batteries? M + and e - M 2+ and 2e - Mg 2+ Ca 2+ Sr 2+ Ba 2+ R. Wang, Y. Cui (unpublished results)

28 Summary - Single valent aqueous batteries: Na +, K + - Divalent aqueous battteries: Mg 2+ - Potentially low cost and scalable - High power - High energy efficient