Fracture of LiyMn2O4 is predicted with a numerical model that calculates the stress generated in spherical particles due to lithium intercalation along the 4-V plateau and phase change along the 3-V plateau. In the former case, fracture is probable at the rates typical of high-power applications, while in the latter case, the probability of fracture is linked not to the discharge rate or particle size, but to the LiMn2O4/Li2Mn2O4 phase ratio. The two-phase material should fracture immediately upon lithium extraction. The effects of variation in thermodynamic factor, diffusion coefficient, and lattice parameter are examined in detail. (C) 2006 The Electrochemical Society
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