IBA 2013 Barcelona March Electrolytes; The Key To Safe Li Electrode Operation? Michel Armand

Transcription

1 IBA 2013 Barcelona March Cations Only Conduction In Polymer Electrolytes; The Key To Safe Li Electrode Operation? C energigune All rights re eserved CI Michel Armand

2 Needs to improve both Ah/kg and Safety of Li batteries High voltages positives Li-Rich : LiMnO 3 -LiMO 2 C 6 Li (385 Ah/Kg) Li 4.4 Si ( 6000 Ah/Kg!) Li metal but 3x-fold excess only 1340 Ah/Kg S electrode. Caveat, S 8 is only 50% in carbon (660 Ah/Kg) 2.2V

3 Safety!! Shenzen, May ; 3 fatalities

4 Where is the market? Consumer electronics 64% automotive 14% Total: (2012) Industry 22% Though an EV battery is 10 4 times larger than OEM

5 Who does what in the EV market? 22% 40% Total: % of EU (2012) 20% production is Lithium metal polymer other Asia Pacific 3% 16% u/

6 A Down to Earth Approach to Energy Density Realistic charge 2 mah/cm 2 specific capacities = Sand Charge f(σ, t + D) Composite? Volume fractions Composite: Volume fractions

7 Classical LMNO li-ion LiC Li 0.2 Mn 2 O 4 C LiMn 2 O 4 NEA: 33 % of total weight $ 5/m 2 Si still 25% E m Wh / kg

8 Lithium Metal System 3Li + FePO 4 2Li + LiFePO 4 7 % of total weight $ 1/m 2 Li = $ 70/kg E m Wh / kg

9 Transport mechanisms Liquid electrolytes: transport of solvated species Polymer electrolytes: transport by solvation /desolvation C operation No net displacement of the host matrix Ceramic electrolytes: transport by ion hopping

10 A Solid-State System in Not a View of the Mind Autolib : 2000 cars on a pay and ride basis in Paris today 250 Km driving range 250 Km driving range C/4 charge rate

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

12 Cost! Li-ion ion = /mo Nissan Leaf LMP = /mo

13 Fabrication process Polypropylene Support Solvents Polymer PP Lithium Salt Synthesis Li[(CF 3 SO 2 ) 2 N] Solvents LiFePO 4 Electrolyte Solution Carbon Black Lamination of SPE & Cathode films PP Lamined Half-Cell Polymer Synthesis Polymer Solvents Preparation of Solutions: Electrolyte and Cathode cathode Slurry Cathode Collector Solvents Enduction and drying of SPE & Cathode films Collector Cathode Electrolyte 2 kwh Modules CE Cell PP laminated Half-cells spraying of metal contacts - Ultrathin Lithium Foil Lithium Calendering / Rolling Extruded lithium film Li Extrusion Li Li Modules Assembly EV & non-ev Packs CE Cells Assembly Production of Lithium Foil commercial Li lingots

14 Polymer Battery Short circuit test (2kWh modules Hydro-Québec) Absence of reaction above the m p of lithium Date of file : Feb 1993!

15 Safety again Courtesy Bolloré 5 autolib cars were torched in the Paris suburbs

16 Consequences of ambipolar Transport X Li + Li + overconcentration conductivity X Li + Li + Dendrites Formation depletion conductivity 0

17 dendrite growth: salt depletion Dendritic growth appears in the space charge following anion concentration 0 (J.-N. Chazalviel, Phys. Rev. A 42 (1990), 7355) ector + colle (a) Experimental setup; (b) copper deposit from CuSO 4 at different currents. (V. Fleury, W.A. Watters, L. Allam, T. Devers, Nature 416 (2002) 716

18 Salting-out solvated electrons LiI

19 Dendrites are not a fatality! electrolyte Al current collector t hium lit electrode composite

20 Characterization Upon Cycling Morphological evolution upon cycling (ex-situ analysis): Pristine After 100 cycles After 600 cycles Courtesy P. Hovington, K. Zaghib, Ireq (Hydro-Québec)

21 No influence upon disposition in the stack 27 cycles 1056 cycles

22 Transport mechanisms Liquid electrolytes: transport of solvated species Polymer electrolytes: transport by solvation /desolvation No net displacement of te host matrix

23 t+ = 1 polymer electrolytes

24 t + = 1 random co-polymer electrolytes + Zhou et al.accepted for publication Electrochimica Acta 2013

25 t + = 1 random polymer electrolytes Free anion state of the art

26 Nanoparticles as polyanion/reinforcement PEO /+ PGDME nano- SiO 2 Villaluenga I., Bogle X., Greenbaum S., Gil de Muro I, Rojo T., & Armand M., submitted to Nature Communications (2013)

27 t + = 1 Block polymers Gyroidal bi-continuous phase A block M 2000 A block M 2000 A block M 2000 Aboulaich A., Maria S, Meziane R, Jean-Pierre Bonnet J-P., Armand M., Lienafa T, Trang N. T. P., Bertin B, Gigmes D.,Denoyel R, Bouchet R., Nature Materials on line (2013)

28 Battery results for Li /LFP

29 Conclusions Li polymer batteries DO exist, and up to now meet SAFETY tests t and surpass all Li ion i for EV application (plug in?); a 60 C operation is a plausible and desirable goal Strategies are now successful to make dendritic growth unlikely (young modulus, t + 1) Li 3x is cheaper than the NEA including copper cc the electrode material! 30 a dense electrode (i.e. Li, Al Mg ) is needed to take advantage of high specific 20 capacities ( S?) 10 I ( nano oa) T=80 C, v=8mvs - Pt =25 m Mg(CF 3 SO3) 2 designer Mg salt V vs. Mg:Mg

30 Thank you for your attention!