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Invited Presentation: Present Understanding of the High Capacity Layered Oxide Electrodes
Tuesday, 10 June 2014: 10:00
Central Pavilion (Villa Erba)
J. M. Tarascon (Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, France, Collège de France, Paris), M. Sathiya (Collège de France, 11, Place Marcelin Berthelot, 75231 Paris, France, ALISTORE-EuropeanResearch Institute, 80039 Amiens, France), K. Ramesha (CSIR– CECRI Chennai centre, CSIR-Campus, Taramani, Chennai-600 113, India), A. M. Abakumov (EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium,), G. Rousse (Collège de France, 11, Place Marcelin Berthelot, 75231 Paris, France, IMPMC, CNRS UMR 7590, UPMC Univ Paris 06, 75252 Paris Cedex 05, France), D. Gonbeau (University of Pau, IPREM-ECP, 64000 Pau, France), M. L. Doublet (ICG-CTMM, RS2E : French Network on Electrochemical Energy Storage), A. S. Prakash (CSIR– CECRI Chennai centre, CSIR-Campus, Taramani, Chennai-600 113, India, Collège de France, 11, Place Marcelin Berthelot, 75231 Paris, France,), and G. Van Tendeloo (EMAT, University of Antwerp)
Li-ion batteries have contributed to the commercial success of portable electronics and may soon dominate the electric transportation market provided that major scientific advances including new materials and concepts are developed. Layered oxides of the general formula LiNi
1/3Co
1/3Mn
1/3O
2, termed as NMC, display the highest capacity (≈ 200 mAh/g) of any presently used positive electrode materials.
1 By modifying the chemical composition through substitution of Li for M in the metal layers, Thackeray’s and Dahn’s groups have confectioned materials displaying reversible capacities exceeding 250 mAh/g.
2-3However, their implementation in practical Li-ion cells is still plagued by the complex electrochemical mechanism and large voltage decay upon cycling. Elucidating the origin of large capacity in these materials and the cause of voltage decay so that a practical solution can be identified remains two fundamental challenges addressed by numerous groups worldwide.
In an attempt to understand both the aforementioned issues, we have designed structurally related Li2Ru1-yMyO3 materials (M= Sn, Mn, Ti; 0 ≤ y ≤ 1).4-6 Containing a single redox-active cation and displaying sustainable reversible capacities as high as 230 mAh/g, the Li2Ru1-ySnyO3 phases turn out to be the ideal system to unambiguously show, based on an arsenal of characterization techniques, that the reactivity of these high capacity materials towards Li entails cumulative cationic (Mn+→M(n+1)+) and anionic (“O2–→O22–”) reversible redox processes.4 To address the voltage decay issue, Ti4+ (d0) substitution was selected owing to its zero CFSE ,similar to Sn4+(d10), and its smaller size (0.60Å); with the expectation that Ti would be more likely to show accelerated cation migration for direct visualization of migration paths.6
The results of such studies will be reported with the hope that they will help the battery community to develop high capacity layered electrodes free from voltage decays upon cycling.
References:
- T. Ozhuku, Y. Makimura, Chem Lett, 30, 642-643 (2001).
- M. M. Thackeray,S-H. Kang, C. S. Johnson, J. T. Vaughey,R. Benedek,S. A. Hackney,J. Mater Chem, 17, 3112-3125 (2007).
- F. Zhou,X. Zhao,A.Van Bommel, X. Xia,J. R. Dahn, J. Electrochem. Soc.158, A187-A191 (2011).
- M. Sathiya, G. Rousse, K. Ramesha, C. P. Laisa, H. Vezin, M. L. Sougrati, M. L. Doublet, D. Foix, D. Gonbeau, W. Walker, A. S. Prakash, M. Ben Hassine, L. Dupont, J.- M. Tarascon,Nat Mater, 12, 827-835 (2013).
- M. Sathiya, K. Ramesha, G. Rousse, D. Foix, D. Gonbeau, A. S. Prakash, M. L. Doublet, K. Hemalatha, J.-M. Tarascon, Chem Mater25, 1121-1131 (2013).
- M. Sathiya, A. M. Abakumov, K. Ramesha, D. Foix, G. Rousse, C. P. Laisa, D. Gonbeau, M. L. Doublet, A. S. prakash, G, van Tendeloo, J-M. Tarascon, Manuscript submitted (Nature Materials)
