Suppressing Fe-Li, Ni-Li Antisite Defects in LiFePO₄and LiNi_1/3Co_1/3Mn_1/3O₂by Optimized Synthesis Methods

Antisite defects in LiFePO4 and LiNi1/3Co1/3Mn1/3O2 cathode materials will severely decrease Li+ diffusion ability and the cell capacity. However, the mechanism of constraining antisite defects during the hydrothermal route is not fully understood. Herein, the Fe-Li, Ni-Li antisite defects in LiFePO4 and LiNi1/3Co1/3Mn1/3O2 cathode materials are successfully suppressed by optimized synthesis methods. As a result, their discharge capacity and rate performance at room and low temperature are significantly enhanced owing to smaller potential difference, less charge transfer resistance, reduced polarization, and enhanced Li+ diffusion coefficient. The comprehensive investigation of synthesis parameters indicates that high attraction and less repulsion force governed by the zeta potential is crucial for making ideal cathode materials by facilitating coalescence, providing the sufficient cations occupation needed, and constructing uniform layer-by-layer surroundings for the precursors.