Keeping up with the increasing demands for electrochemical energy storage

Transcription

1 Keeping up with the increasing demands for electrochemical energy storage Jeff Sakamoto 2015 Top of the learning curve: optimize current technology 2020 Frontiers of Li-ion technology: new materials 2030 Frontiers of energy storage: beyond Li-ion technology 1

2 Quantifying the demand for energy storage Power: Watts = current voltage Energy: Watts time = Watt hours Specific Energy: Wh/kg Energy Density: Wh/liter 2

3 Current and future energy storage tech fuel cells? + - capacitors Wh/kg fly Wh/kg wheels Batteries Thermoelectrics Pb Wh/kg acid NiMH Wh/kg Lithium Beyond Lithium Courtesy S. Whittingham Li-metal safety Li-ion Li-sulfur Li-air? Na, Mg, 3

4 Is there enough lithium? Enough Li for: HEV PHEV BEV Courtesy of Ted Miller 4

5 Current Li-ion: Nuts & Bolts LiMO 2 Dunn, B., Kamath, H. and Tarascon, J.-M Science 334: Ponticel. P, 2012,, Society of Automotive Engineers: Vehicle Electrification:

6 Frontiers of Electrochemical Energy Storage Specific Energy Energy Density Cost Climate Change Committee (2012) Final Report prepared by Element Energy Limited, Cambridge, UK. 6

7 Frontiers of Electrochemical Energy Storage Bruce, P. G., Freunberger, S. A., Hardwick, L. J. and Tarascon, J.- M Nature Materials 11: Thackeray, M., M., Wolverton, C. and Isaacs, E. D Energy and Environmental Science 5:

8 2020 Frontiers of Li-ion technology: new materials (> 200km range, <$150/kWh) LiMO 2 Ponticel. P, Society of Automotive Engineers: Vehicle Electrification: Electrode capacity: how much Li/mass (mah/g) 8

9 2020 Anode: alloy vs. intercalate Li Graphite anode = ~330 mah/g (theoretical = 372 mah/g) Si anode = ~1000 mah/g (theoretical > 4000 mah/g) Cui et al. (2012) Nature nanotechnology letters. Gorilla Glass +) Si is abundant & cheap +) Increase in capacity +) Low voltage?) Cycle life; 300% volume change?) Cost of manufacturing nano Si 9

10 Li + O 2- M Li + O 2- x+ Li + O 2- M O 2- M x+ O 2- M x+ O 2- M x+ O 2- M x+ x+ O 2- Theoretical Li 1 MO 2 ~ 280 mah/g Practical Li 0.5 MO 2 ~ 140 mah/g 10

11 2020 Cathode: maximize Li utilization Li 2 MnO 3 -stabilized Li 1 MO 2 : ~ 286 mah/g Layered cathodes: Thackeray et al Argonne National Lab. +) Doubling of capacity +) No new elements?) Slow kinetic/power?) Crystallographic stability?) > 4.5V: no electrolyte 11

12 2020 Impact of new materials 14% 34% 29% 5% 5% 13% Active Anode Inactive Anode Separator Active Cathode Inactive Cathode Housing Adapted from: Johnson, B.A. & White, R.E. Journal of Power Sources 70, (1998). 12

13 2030 Frontiers of energy storage: beyond Li-ion (> 400km range, <$150/kWh) Conventional Li ion technology Li metal LiMO 2 Air (O 2 ), sulfur? ++) 3375 mah/g (10X over graphite) ++) Li-Sulfur 2,500 Wh/kg Theoretical ++) Li-O 2 3,500 Wh/kg Theoretical 13

14 2030 Li-O 2 dry (>500 km range, < $150 kwh) Bruce et al Nature Materials 11: catalyst O 2 Li + e - LiO x ++) High Specific Energy +) O 2 is ubiquitous?) Must separate O 2?) Kinetics/Power/Hysteresis?) Li metal anode stability 14

15 2030 Li-Sulfur (>400 km range, < $150 kwh) Li metal LiMO 2 Bruce et al Nature Materials 11: Ji, X. and Nazar, L. F J. Mater. Chem., 20, ) High specific energy +) Cheap, abundant +) Light +) 2 Li for every S (Li 2 S)?) cycling?) Sulfur conductivity?) Li metal anode stability 15

16 2030 Beyond Li-ion requires new electrolyte Beyond Li-ion Conventional Li ion technology LiMO 2 Lithium Air, sulfur?? Solid electrolyte 16

17 2030 Sakamoto Group: Engineering nothing Atoms Gas molecules Solvated ions & proteins Macro scale phenomena Å Å-2nm 2-50nm >50nm Li-ion lung : Li-ions move from large linear to small orthogonal capillaries Conventional electrode Atomic-scale vacancies facilitate ion transport in ceramic electrolytes Micro pores impede gas transport Li + Oxford University Press: Oxford Illustrated Science Encyclopedia Engineered electrode Meso pores deliver proteins to linear macro pores that guide nerves Meso pores connect molecular-scale phenomena to the macro-scale 17

18 Ceramic electrolyte: Li 7 La 3 Zr 2 O 12 garnet Advantages Li Conductivity similar to liquid 298K First bulk, oxide electrolyte stable against Li Stable up to 9 V S. Ohta, T. Kobayashi, T. Asaoka, J. Power Sources 196 (2011) Can be synthesized/processed in ambient air ZrO 6 LaO 8 E. Rangasamy, J. Wolfenstine and J. Sakamoto, Solid State Ionics, 206, (2011). Xu et al. PHYSICAL REVIEW B 85, (2012) First Report: R. Murugan, V. Thangadurai, W. Weppner, Angew. Chem. In. Ed (2007). 18

19 Towards cycling Li metal anodes? LLZO Garnet 100 mm Sakamoto group, cycled LLZO S. Ohta et al., Journal of Power Sources, vol. 196, no. 6, pp (2011). 19

20 Solid-state, All Ceramic Batteries Notten et al. Phillips (2009) Weppner et al. (1999) +) No organics to degrade +) Synthesized and fabricated in air +) Significant reduction in packaging +) Non-flammable +) Gets better with increasing temp Sakamoto group (2011)?) Interface integrity?) Kinetics/Power?) Thermomechanical stresses 20

21 Conclusions 1. Energy density (Wh/kg) must increase by ~4X 2. Cost ($kwh) must decrease by ~4X goal: integrate new materials into current Li-ion goal: must go beyond Li-ion requiring: Li metal anodes New cathodes Li-O 2 Li-Sulfur 5. Opportunities New solid and liquid electrolytes Electrode and battery designs Additive manufacturing Predictive analysis Packaging 21