Energy Storage Yi Cui Department of Materials Science and Engineering Stanford University Stanford Institute for Materials and Energy Sciences SLAC National Accelerator Laboratory CA, ~60 GWh World ~10 TWh ~85,000Wh ~1million soon ~70Wh ~10 Wh 1 billion pieces/yr Lithium Ion Battery Cells: Now and Future Goals Cell level (goal) System level (goal) Energy ~200 (600) ~100 (300) (Wh/kg) Cost 150-200 (70) 300-500 (150) ($/kWh) Cycle life 3000 (10,000 for grid) Safety Grand Challenges of Batteries - High energy density: 3x - Low cost: 3x lower - Safe Revolution in Transportation, Grid, Renewable Cui Group Energy Storage Program High capacity chemistries: Pre-storage of Li-ions - Si, Li metal anodes Advanced tools: - S cathodes - In operando TEM - P anodes - In operando X-ray Semiflow batteries for grid Solid-state electrolyte Architecture design and safety High Energy Lithium Batteries Current negative electrodes Graphite (2D): 370 mAh/g Future negative electrodes (10 time higher capacity) Silicon: 4200 mAh/g Li metal: 3860 mAh/g High Energy Lithium Batteries Current positive electrodes LiCoO (2D) LiMn O (3D): 2 2 4 LiFePO (1D) 150mAh/g 150 mAh/g 4 170mAh/g Future positive electrodes (10 time higher capacity) Sulfur (S ) ~1670 mAh/g 8 Li2S Theoretical Specific Energy Cathode 6X 3X Theoretical Specific energy (wh/kg) Specific energy Theoretical Silicon Anodes With 11X Specific Capacity 4200 mAh/g 370 mAh/g Break Individual particle: For Si: volume expansion to 4 times Problems: 1) How to avoid breaking? 2) How to build stable solid-electrolyte-interphase (SEI)? 1st GCEP Project Funding on Battery (Jan, 2007): Nanowire Battery PI: Yi Cui, co-PI: Fritz Prinz In-situ Transmission Electron Microscopy (TEM) 2mm Nanofactory TEM-STM holder (M. McDowell, C. Wang, Yi Cui, Nano Energy 1, 401, 2012) Fracture of Surface Cu Coatings 12 5x actual speed Nanoparticle critical breaking size: ~150nm Nanowire critical breaking size: ~300nm (M. McDowell, I. Ryu, S.W. Lee, W. Nix, Y. Cui Adv. Materials 24, 6034 (2012)) 11 Generations of Si Anode Design from Cui Group Gen 1: Nanowire Gen 2: Core-Shell Nanowire Gen 3: Hollow Nature Nanotechnology 3, 31 (2008). Nano Letters 9, 491 (2009). Nano Letters 11, 2949 (2011). Gen 4: Double-walled hollow Nature Nanotechnology 7, 310 (2012). Gen 6: Si-hydrogel Nature Communication 4:1943 (2013) with Zhenan Bao Gen 5: Yolk-shell Nano Letters 12, 3315 (2012). 11 Generations of Si Anode Design from Cui Group Gen 7: Self-Healing Gen 8: Pomegranate-Like Gen 10: Nature Chemistry 5, 1042 (2013). Nature Nanotechnology 9, 187 (2014). Prelithiation of Si anodes with Zhenan Bao Nature Communications 5, 5088, 2014 Gen 9: Non-filling carbon coating or porous Si ACS Nano 9, 2540 (2015). Gen 11: Micro-Si gaphene cage Nature Energy 15029, 2016 Gen 8: Pomegranate-Like Si Batteries - Reduce surface area - Increase mass loading - Dense packing N. Liu, Z. Lu, Y. Cui Nature Nanotech 9, 187 (2014). Gen 8: Pomegranate-Like Si Batteries N. Liu, Z. Lu, Y. Cui Nature Nanotech 9, 187 (2014). Gen 7: Self-Healing Batteries C. Wang, H. Wu, Y. Cui, Z. Bao Nature Chemistry 5, 1042(2013) 3-8 µm Si particles C. Wang, H. Wu, Y. Cui, Z. Bao Nature Chemistry 5, 1042(2013) Battery Safety - Smart separators for detecting internal shorts - Reversible thermal fuse inside batteries Battery Safety In the News… Airplanes Electric cars Hoverboard Consumer electronics External short: accident Internal short: overcharge defects, charge at cold weather Fast release of battery electricity Battery temperature >90-120°C Exothermic decomposition of SEI Battery temperature >180°C Exothermic reaction of oxide cathode with electrolyte Thermal Runaway Smart Separators for Battery Safety Hui Wu, Denys Zhuo, Yi Cui Nature Communications 5: 5193 (2014). Battery Safety: Reversible Thermal Fuse Z. Chen, Y. Cui, Z. Bao Nature Energy (2016) Ni Nanospikes coated with graphene Ni nanospikes mixed with polyethylene polymer Z. Chen, Y. Cui, Z. Bao Nature Energy (2016) Reversible Thermal Fuse Reversible Thermal Fuse Z. Chen, Y. Cui, Z. Bao Nature Energy (2016) Impact of GCEP Funding 2005-2008 Little US government funding on batteries Jan 2007, $1.6M New efficient catalysts 1st GCEP Battery Project 100x external funding 60x 1) KAUST investigator 2) ONR Young Investigator 3) DOE EERE BMR Program - Si anode - S cathode - Li metal - Battery materials and characterization 4) Battery Hub (JCESR) 5) Battery 500 Consortium Commercialization of Si Anodes from Cui Group 2007 Si nano anode invention in Cui group 2008 April, Amprius founded 2009 Feb, Series A $5M 2011 Mar, Series B $25M 2013 Dec, Series C $30M 2014 Wuxi City Joint Venture, Series D $40M, production 2016 More than a few million batteries sold in market Amprius Product Line: Gen 1: in production (2013), 650 Wh/L, 270 Wh/kg Gen 2: in production (2016), 750Wh/L, 280Wh/kg Gen 3: in pilot (2016), 900Wh/L, 360Wh/kg Amprius, Sunnyvale Nanowire production tool Amprius, Wuxi Amprius, Nanjing Consortium Battery500 Consortium Battery500 Battery500 Consortium . The Battery500 Consortium aims to triple the specific energy (to 500 WH/kg) relative to today's battery technology while achieving 1,000 electric vehicles cycles. The consortium aims to overcome the fundamental scientific barriers to extract the maximum capacity in electrode materials for next generation Li batteries. The consortium leverages advances in electrode materials and battery chemistries supported by DOE. Consortium Battery500 The People Executive Committee J. Virden, D. Schwartz, M. Hartney, G. Tynan, K. Adjemian, A. Harris Advisory Board S. Chu(Stanford), JB Straubel(Tesla), Operation Deputy, M. Hartney Director, Jun Liu W. Wilcke(IBM), auto industry Project Coordinator, N. Henderson Safety Manager, M. Gross IP Manager, P. Christiansen Industry Committee Co-Director, Yi Cui Chief Scientist, A. Manthiram Seedling project Keystone Project 1 Keystone Project 2 Keystone Project 3 500 Wh/kg V. Subramanian/ Materials and Interfaces Electrode Architecture Cell Design and Integration 1000 cycles X. Yang J. Zhang/S. Whittingham E. Dufek/P. Liu V. Vishwanathan/J. Yang Industry Off-Ramp New Test Bed Spin Off Using ideas from batteries to find better catalysts Important Electrochemical Reactions + - 0 V HER: 2 H + 2 e H2 Pt, 0 V 1.23 V - - OER: 4OH - 4e 2 H2O + O2 IrO2, RuO2, 1.5 V Searching for catalysts: - as efficient or better for HER, OER etc. - high abundance, low cost, robust - CO2 reaction catalysts Edge Terminated MoS2 and MoSe2 500 C for 10 min MoS2 MoSe2 D. Kong, H. Wang, Y. Cui , Nano Lett. 13, 1341 (2013) Chemical Potential Tuning of Electrocatalysts - - 1.23 V 4 OH - 4 e 2 H2O + O2 MoS Li+ + e- Chemical Potential Chemical 2 + - 0 V 2 H + 2 e H2 Electrochemical Tuning of Catalysts Pristine 1.8V 1.5V 10 nm 1.2V 1.1V H. Wang, Z. Lu, Y. Cui PNAS 110, 19701 (2013) Electrochemical Tuning of HER Catalysts H. Wang, Z. Lu, Y. Cui PNAS 110, 19701 (2013) Bifunctional Catalyst for Overall Water Splitting Morphology tuning by Lithium conversion reaction MOx+2xLi M+xLi2O Example: CoO H. Wang, Y. Cui, Nature Communications 6, 7261, 2015. Electrochemical Tuning of CoO H. Wang, Y. Cui, Nature Communications 6, 7261, 2015. Same NiFeOx/CFP catalyst for both OER and HER in the same solution OER HER H. Wang, Y. Cui, Nature Communications 6, 7261, 2015. Strain-tuning of catalysts Using Battery Electrode to Tune Catalyst Strain LiCoO2 tuning: generate 5% compression and 5% tension. H. Wang, F. Prinz, J. Norskov, Y. Cui (Science, in press, 2016) H. Wang, F. Prinz, J. Norskov, Y. Cui (Science, in press, 2016) Tuning the Pt Strain for ORR H. Wang, F. Prinz, J. Norskov, Y. Cui (Science, in press, 2016) H. Wang, F. Prinz, J. Norskov, Y. Cui (Science, in press, 2016) Future of Batteries High Energy Battery Cells 1) Graphite/NMC: ~300Wh/kg 2) Si/NMC: ~400Wh/kg 3) Li metal/NMC: ~500Wh/kg Li metal/Sulfur: >500 Wh/kg Grid Scale Battery Cells 1) Aqueous batteries 2) Flow batteries 3) Li ion batteries Acknowledgement Collaborators: - William Nix Fundings - Mike Toney (SLAC) - DOE EERE Vehicle Technology Office, BMR Program - Zhenan Bao - JCESR (Joint Center for Energy Storage Research) - Robert Huggins - Battery 500 Consortium - Hongjie Dai - GCEP - Steven Chu - Jens Norskov Backup slides Global reserve of lithium: 40 million ton Nissan Leaf, 24 kWh, 84 miles Tesla S model, 85 kWh, 265 miles 4 kg Lithium 14 kg Lithium 10 Billion Leaf 3 Billion Tesla There are ~1 billion cars in the world. In 2009, Li production: 92,000 ton, which is 23,000,000 Nissan Leaf. Ocean: 230,000 million ton (0.1778ppm) World Electricity Consumption: ~4 TW Need TeraBattery for 6 hours: ~24 TWh Global reserve of lithium: 40 million ton Battery 240TWh Our GCEP Programs on Batteries 2007-2010: Nanowire Battery (Yi Cui, Fritz Prinz) 2010-2013: Prussian Blue Materials for Aqueous Batteries for Grid Scale Storage (Yi Cui, Robert Huggins) 2013-2016: Self-Healing Polymer Batteries (Zhenan Bao, Yi Cui) .