Materials Design for Grid-Scale Energy StorageEnergy Storage for the Electricity Grid: Benefits and...
Transcript of Materials Design for Grid-Scale Energy StorageEnergy Storage for the Electricity Grid: Benefits and...
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
Solar Wind
Electric grid
Energy Storage: Enable Renewable Penetration
- Smooth fluctuations: seconds-to-minutes-to-hours
- Peak shifting: hours-to-days
Grid Scale Energy Storage
Life: 20-30 Years
Low-cost:
- Initial cost: <$100/kWh
- Life time cost: <$0.025/kWh cycle
Scalable (~MW-GW/plant) to TW
Cycle life: > 5000 cycles
Round trip energy efficiency: >90%
Energy density: affecting cost
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• Pumped hydroelectric power:
- Scalable, low-cost, long life.
- Location dependent, low energy density, low energy efficiency.
Electricity Energy Storage Technology Options. EPRI, Palo Alto, CA: 2010. 1020676.
Existing Storage Technologies Are Not Adequate
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1. Electricity Energy Storage Technology Options. EPRI, Palo Alto, CA: 2010. 1020676.
2. Energy Storage for the Electricity Grid: Benefits and Market Potential Assessment Guide.
Sandia National Laboratories, Albequerque, NM, and Livermore, CA: 2010. SAND2010-0815.
3. 2020 Strategic Analysis of Energy Storage in California. California Energy Commission, Sacramento, CA: 2011. CEC-500-2011-047.
Too Expensive Not Enough Cycles
Existing Electrochemical Energy Storage
Not yet scalable:
World annual Li-battery production: 40GW for 1 hr.
Need 30 years to get to 1TW scale.
Battery Basics
(Courtesy of Venkat Srinivasan)
1) Low-cost abundant materials
- Electrode
- Electrolyte
- Separators
2) 500 cycles need to go to 50,000 cycles
2) Scalable processing to make batteries
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Prussian Blue: Open Framework
Ferric ferrocyanide hydrate:
KFeIIIFeII(CN)6 ·nH2O
R P
Channel Through Framework
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Open Framework Allows Fast Ion Transport
Crystal Ionic Radius
Li+ 0.59-0.73 Å
Na+ 1.12 Å
K+ 1.52 Å
Shannon, R. D. Acta Cryst., A32, 751 (1976).
Prussian Blue analogues:
Channel radius: Rc = 1.6 Å
LiCoO2:
Channel radius: Rc = 0.43 Å
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• Open Framework Crystal Structure: APR(CN)6·nH2O
– P and R = Transition Metals, A = Alkali Ions
R P
Examples:
• Prussian Blue:
P=Fe3+ R=Fe2+
• Copper Hexacyanoferrate
(CuHCF):
P=Cu2+ R=Fe3+
• Nickel Hexacyanoferrate
(NiHCF):
P=Ni2+ R=Fe3+
A Family of Prussian Blue-Like Materials
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Synthesis of Prussian Blue Analogues
Room-temperature aqueous chemical reaction of transition metal salts. Result: spontaneous precipitation of solid product.
Example: Prussian Blue
General synthesis:
A = K+, Na+
P = Fe, Cu, Ni, Co, Mn, Zn…
R = Fe, Cr, Mn…
K Fe3 Fe II CN6
4KFeIIIFe II CN
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A P2 RIII CN6
3APR CN
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(C. Wessels, R. Huggins, Y. Cui, Nature Communication, 2:550 (2011))
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Copper Hexacyanoferrate As Ultrafast Positive Electrodes
1 M K+ Aqueous Electrolyte:
(C. Wessels, R. Huggins, Y. Cui, Nature Communication, 2:550 (2011))
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1 M K+ aqueous electrolyte:
(C. Wessels, R. Huggins, Y. Cui, Nature Communication, 2:550 (2011))
Copper Hexacyanoferrate As Ultrafast Positive Electrodes
Also Work Well in Na+ Electrolyte
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Rate Capability of Copper Hexacyanoferrate
(C. Wessels, R. Huggins, Y. Cui, Nature Communication, 2:550 (2011))
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Cycle Life of CuHCF/1 M K+ at 17C
Ultralong Cycle Life of Copper Hexacyanoferrate
(Yi Cui Group, Nature Communication, 2:550 (2011))
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Near Zero Strain: Stable Open Framework
CuHCF 400 Peak vs. Charge State CuHCF a0 vs. Charge State
400
Reason for strain: 2·∆rFe-C = 0.1 Å
∆a0 = 0.1 Å Strain = 0.1%
(Yi Cui Group, Nature Communication, 2:550 (2011))
C. Wessels, R. Huggins, Yi Cui ACS Nano, 6, 1688 (2012).
Tuning the Voltage: Cu, Ni HCF and Their Solid Solution
CuHCF Open Framework: Effects of A+ ions
C. Wessels, R. Huggins, Y. Cui, Journal of The Electrochemical Society, 159 (2) A98-
A103 (2012)
What About Negative Electrodes?
Need negative electrodes with potential ~0V versus H2/H+
time
Po
tenti
al v
s. S
HE
/ V
1.0
0.25
-0.10
(+) CuHCF
(-) Activate Carbon (AC)
(-) PPy/AC
-0.30
What About Hybrid Negative Electrodes?
(+) CuHCF
(-) 10% PPy/AC
NaBH4
[K+]=1M, pH=1, 1 C
Hybrid Negative Electrodes
M. Pasta, R. Huggins, Y. Cui Nat. Comm. (2012), In Press.
Open Framework Battery: Full Cell Potential Profile
(+) CuHCF
(-) 10%PPy-AC
([K+]=1M, pH=1, 10
C)
Full Cell
M. Pasta, R. Huggins, Y. Cui Nat. Comm. (2012), In Press.
CuHCF- PPy/C Full Battery: Cycle Life
([K+]=1M, pH=1, 10 C)
M. Pasta, R. Huggins, Y. Cui Nat. Comm. (2012), In Press.
Manganese (II) Hexacyanomanganate (III) MnIII—C≡N—MnII
Mn(II), P site
Mn (I, II, III), R site
Open Framework Structure Negative Electrodes
M. Pasta, Y. Cui (unpublished results)
CV MnIIHCMnIII, NaClO4 sat. pH=7, 2 mV/s
MnII—N≡C—MnIII/II
M. Pasta, Y. Cui (unpublished results)
Mg2+ Ca2+
What About Divalent Ion Batteries?
Sr2+ Ba2+
R. Wang, Y. Cui (unpublished results)
M+ and e-
M2+ and 2e-
Summary
- Single valent aqueous batteries: Na+, K+
- Divalent aqueous battteries: Mg2+
- Potentially low cost and scalable
- High power
- High energy efficient