Power the future CIC March 21st 2012

Transcription

1 Power the future CIC March 21st 2012 Batteries, Past, Present and Future Michel Armand 2010 CIC energigune All rights reserved

2 1 Billion Cars in 2010 and and 1.3 Millions fatalities on the roads! > 2 millions deaths from air-borne particles in big cities

3 When Non-Weapon Science Interested even Dictators Volta s demonstration of his pile to Napoleon Queen Victoria attended Faraday s lectures at the Royal Institution

4 Solid-State Batteries Zamboni's solid-state Battery (1813) Pila elettrica a secco Zinc / solid electrolyte / MnO 2 -Ag elementary cells Solid electrolyte : honey!

5 Our forefathers - Sodium? - Yes Sir. Mixed with mercury, it forms an amalgam which replaces zinc in Bunsen cells. The mercury lasts forever. Only sodium is consumed and the ocean provides it. Furthermore, sodium batteries are the most energetic, and their electromotive force is double that of zinc cells. Jules Verne Twenty Thousand Leagues Under The Sea Publisher, Paris 1870 Hetzel The H 2 overpotential induced by mercury allow to go for very negative voltages (-2V)

6 Needs for electrochemical storage Automobiles Load-levelling cars 10% electric tons batteries World electricity production = kwh 10% stored/d 10 9 tons batteries Sustainability a prime criterion!

7 Elements and mankind 20 tons of CO 2 / ton of Al 2 ton of CO 2 / ton of Fe 50 tons of CO 2 / ton of Cu! Price of copper likely to increase further!

8 Time Scale Planté s Lead/acid Displacement, 2Φ Leclanché Primary H x MnO 2 1β alumina Na/S Lithium polymer NiO 2 H x / H y Me Dual insertion Lithium-ion 30 Wh/kg 150 Wh/kg Intercalation/ insertion electrodes

9 Electrode materials 3D Li +, e -, semi-conductor LiMn 2 O 4 Very poor e - σ 1D ionic (poor) LiFePO Intercalation materials 2D semi-metal TiS 2, graphite Disulfides S S Non-conductors First biomimetic reactions Discrete molecules Non-conductors Radical species LiCoO 2, LiMn 1/3 Co 1/3 Ni 1/3, LiMn 1.5 Ni 0.5

10 Why lithium? Li + is able to diffuse in most solid structures or cleave many metallic or ionocovalent bonds Strong oxidizing agent positive electrode metallic Lithium Oxides (lamellar) Li x CoO 2, Li x V 2 O 5 but 3D (LiMn 2 O 4 ) Strong reducing agent negative electrode Lithium intercalated in graphite

11 The Perfect Half-Cell Lithium Lisicon Sodium β alumina Lithium (solid-stat te) Anything solid, liquid Almost ph Not everything S 8 S 3 Na 2 NiCl 2 Ni + 2NaCl Difficult wit aq. sol (H + exchange) Miracle layer Na liquid

12 3 Families of electrolytes Glasses: SiS 2 /Li 2 S/LiI PEO / [(LiCF 3 SO 2 ) 2 N] Liquids: LiPF 6 in THF T g 270 C; t Li+ = 1 T g -40 C; t Li+ = 0.3 T g -100 C; t Li+ = 0.3 σ T -40 C; t = 0.3 Ionic Liquids Temperature of operation C 25 C C 0 C liquid glass polymer 10 3 /T Gels

13 Batteries and C Polymer liquid Li Solid-state batteries T > 50 C Only Cu liquid All LiPF 6 gel Only Al current collectors Li-ion batteries -20 < T < 55 C Higher energy density But which electrolyte??

14 Driving Range Li-ion ion = 150 km Nissan Leaf Lithium metal / polymer = 250 km Taxi on average country 230 Km/day

15 Stability Domains F - /F 2 Onset of Al corrosion Lithium rich LiMn 1.5 Ni 0.5 O 2 (electrolyte dependent) Cl - /Cl 2 Li 4 Ti 5 O 12 Li/Al alloy formation Li metal silicon

16 Stability Domains F - /F 2 Onset of Al corrosion Lithium rich LiMn 1.5 Ni 0.5 O 2 (electrolyte dependent) Cl - /Cl 2 Li 4 Ti 5 O 12 Li/Al alloy formation Li metal silicon

17 Stability Domains F - /F 2 Onset of Al corrosion Lithium rich LiMn 1.5 Ni 0.5 O 2 Al oxidation with LiPF 6 Requires Fluorine to withstand anion (electrolyte dependent) oxidation Cl - /Cl 2 Li 4 Ti 5 O 12 Li/Al alloy formation Li metal silicon

18 The Cconventionals ClO 4 - BF 4 - poor conductor Explosive! Toxic! PF - AsF SbF - 6 Tendency to décompose according to equilibrium: LiPF 6 PF 5 + <LiF> PF 5 +H 2 O HF Destruction of electrolyte and interfaces ( dissolution of Mn, Fe )

19 T > 220 Runaway! RUNAWAY!! Electrolyte boiling +80 C 180 Lithium melting Operation starting +50 C Liquid Electrolytes - 20 C Electrolyte freezing Under the hood climate Polymer Electrolytes -40 C

20 T > 220 Runaway! 180 Lithium melting RUNAWAY!! Electrolyte boiling! +80 C Operation starting +50 C Liquid Electrolytes Lithium metal plating - 20 C Electrolyte freezing Under the hood climate Polymer Electrolytes -40 C

21 Aging / Failure modes Li-ion LMP

22 Active / Passive Safety Electrode Technology Chemistry LiMn 2 O 4 LiFePO 4 Short circuit Electrolyte oxidizer Life-time spécific capacity (Wh/kg) BMS simplicity Toxicity in cas of fire

23 FSI more conductive than LiPF 6 larger t + 1/3 fluorine, S F far more covalent than P F Normalized Heat Flow ( mw/mg) C Li x C 6 / 1M LiFSI in EC+DMC 200 C Li x C 6 /LP30 Safer with carbon electrode T( C) more favourable low temperature phase diagram / σ

24 Graphite Electrode without alicycliques carbonates, < 4V 600 Charge/Discharge capacity acity (mah g -1 ) (b) Efficiency (%) (b) (a) n cycle (a) New EC/DMC/LiPF n cycle

25 Hydrolysis at RT: LiFSI vs. LiPF 6 HF in LiPF 6 solutions 7500 or H 2 O (ppm) HF H 2 O in LiLiFSI solutions H 2 O in LiPF 6 solutions LiPF 6 : immediate and quantitative hydrolysis LiFSI: no hydrolysis HF in LiFSI solutions t (min)

26 Hückel anions Aromaticity 4n + 2 «π» electrons X = N, C-CN, CR F, S(O)R F DCTA no F, stable to Li, LFP TDI, stable to LMO

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28 Conséquences of ambipolar Transport X - Li + Li + surconcentration conductivité X - Li + Li + Formation de dendrites appauvrissement conductivité 0

29 Osmotic / mechanical forces SEI Electrode e material Lattice expansion of intercalation

30 t+ = 1 polymer electrolytes

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32 Towards 2 electrons / Transition Metal Calculate ed Voltage (V) (a) GGA+U y = 0 y = 0.5 y = x in Li FeSiO N Potential vs. composition for the system Li 2-x FeSiO 4-y N y for y = 0.5 and y = 1

33 Elements and mankind

34 Electrochemical performances of Na 2 FePO 4 powders in Na 2 FePO 4 F/ Na cells Positive electrode: 90% w/w (Na 2 FePO 4 F+ 5 % carbon-coating) + 10 % mass C (SP) Potential. vs N Na + /Na (V) Ceramic synthesis Capacity (mah/g) Rate: C/ N u m ber of cycle x in Na x FePO 4 F Potential. vs Na + /Na (V) Capacity (mah/g) Ionic liquid synthesis Rate: C/ N u m b e r o f c y c le X in Na FePO F x 4 Na 2 FePO 4 F ceramic synthesis: reversible and sustainable capacity of 95 mah/g Na 2 FePO 4 F : reversible and sustainable capacity of 110 mah/g (> 90th)

35 Towards 2 electrons/ transition metal Calculate ed Voltage (V) (a) GGA+U y = 0 y = 0.5 y = x in Li FeSiO N Potential vs. composition for the system Li 2-x FeSiO 4-y N y for y = 0.5 and y = 1

36 Conclusions The future and markets for electrochemical storage are towering; but: Electrolytes are the key to improvements of lifetime, and SAFETY Have liquid electrolytes reached their limits? Polymers, ceramics? Only in such electrolytes can t + be 1 and are more likely to by-pass usual thermodynamics LFP and LiMn 2 O 4 result in energy densities, but the former allows to a real chemical approach to salt and solvents design. Sodium will be the key to grid storage, at 100 Wh/Kg How to go to 200 Wh/Kg and beyond??

37 Thank you for your attention!

38 Strategies Positives: Inorganic: LiFePO 4, Li 2 Fe(Mn)SiO 4 Organic: Li 2+x C 6 O 6 Medium capacity high voltage Very large capacity low voltage Electrolytes: New solutes, polymer (gels) ± ILs Negatives: Inorganic: Si Organic dicarboxylates Very high capacity Cu mandatory / binders? High capacity, 0.8 V Al option, σ elec??

39 Nano-painting importance of nanowiring Carbon coating 1nm thick, transparent to ions Structured carbon black nano particles Electrolyte

40 The role of solvation - + Protic solvents (water) Non-protogenic solvents I - Li + design of polyatomic anions Chemical fragility

41 Anodic limit (Al, EC-DMC) 2 ) I (ma.cm anodic stability EC DMC Al 30 mvs -1 TDI <I>/mA LP30 LiTFSI B 5,6 4,8 4 3,2 2,4 1,6 10 0, V vs. Li + :Li (V)

42 Aging / Failure modes Li-ion LMP Simplistic remedy: Add a Mn ++ trap N(i)C(o)A(l), ⅓,⅓,⅓ 15-50% unsustainable (Co), toxic (Ni)! Less safe than LiMn 2 O 4