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AKE: Arbeitskreis Energie
AKE 8: Energy Storage I, Mobility, Materials
AKE 8.2: Vortrag
Dienstag, 17. März 2015, 11:15–11:30, A 151
Understanding the conversion reaction in Cu3P anode material of Li-ion batteries — •Jatinkumar Rana1, Marian Stan2, Richard Kloepsch2, Jie Li2, Gerhard Schumacher1, Martin Winter2, and John Banhart1,3 — 1Helmholtz-Zentrum Berlin — 2MEET Battery Research center, Münster — 3Technische Universität Berlin
We investigate structural changes in Cu3P anode material by X-ray Absorption Spectroscopy (XAS). The material was synthesized via a wet mechanochemical route and demonstrated a satisfactory electrochemical performance. XAS data were recorded at various states of charge and discharge of the Cu3P/Li cell. The overall electrochemical reaction can be represented by: Cu3P + 3Li ↔ Li3P + 3Cu. During discharge, lithium insertion into the Cu3P phase is observed to occur by substituting Cu+ in the structure with Li+, giving rise to the formation of a series of intermediate phases such as LiCu2P, Li2CuP and finally Li3P and nano particles of elemental copper. During subsequent charge, oxidation of elemental copper occurs and the resultant Cu+ displaces Li+ in the structure, giving rise to the reformation of the original Cu3P phase. The close structural resemblance between Cu3P and the end member Li3P and the formation of extremely small-sized copper particles, are believed to be the reasons for the reversible nature of the conversion reaction in the material.