Suppression of Phase Separation in LiFePO4 Nanoparticles During Battery Discharge

Abstract

Using a novel electrochemical phase-field model, we question the common belief that LixFePO4 nanoparticles separate into Li-rich and Li-poor phases during battery discharge. For small currents, spinodal decomposition or nucleation leads to moving phase boundaries. Above a critical current density (in the Tafel regime), the spinodal disappears, and particles fill homogeneously, which may explain the superior rate capability and long cycle life of nano-LiFePO4 cathodes.

27 pages, 8 figures

References in corpus (2)

• Phase field modeling of electrochemistry I: Equilibrium
• Phase Field Theory of Heterogeneous Crystal Nucleation

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