Suppression of Phase Separation in LiFePO4 Nanoparticles During Battery   Discharge
  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. 
Peng Bai, Daniel A. Cogswell, and Martin Z. Bazant (MIT)
cond-mat.mtrl-sci physics.chem-ph