|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Advanced Materials for Energy Conversion and Storage
||Mapping the Kinetic Modes of Phase Transformation in Intercalation Compounds
||Ming Tang, Liang Hong, Linsen Li, Song Jin
|On-Site Speaker (Planned)
Many important battery electrode materials undergo first-order phase transformations upon cycling. In literature, phase transformations accompanying the intercalation process are usually considered to be either bulk-transport-limited (BTL) or surface-reaction-limited (SRL). The actual mechanisms nonetheless remain inadequately understood due to challenges in direct observation of phase growth in individual particles. Using LiFePO4 as a model system, we predict from phase-field modeling that phase transformation could exhibit richer and unexpected kinetic behavior in intercalation compounds. A new hybrid mode, in which phase boundary migration is SRL or BTL along different directions, is identified. This finding is confirmed by in operando x-ray transmission microscopy, and elucidates the importance of the interplay between surface reaction and diffusion in determining the transformation rate. In particular, our study leads to a surprising prediction that lattice defects in LiFePO4, which block 1D  channels and reduce Li diffusion anisotropy, could benefit the rate performance of batteries.
||Planned: Stand-alone book in which only your symposium’s papers would appear (indicate title in comments section below)