We provide a review of our recent studies on the surface chemistries and electronic structures of olivine phosphate cathode materials LiMPO₄ (M = Mn, Fe, Co, Ni). Li-depletion and mixed oxidation for the transition metal ions have been detected on particle surfaces, across the family of metal phosphate cathode materials. The effects of surface Li-depletion on optical properties and electronic band structures are discussed. LiFePO₄ doped with metals or ions that are reported in the literature as beneficial for rate capability enhancement show more pronounced surface Li-depletion and mixed oxidation compared to undoped material. This outcome, among others, indicates that the dopant resides predominantly on, and influences, the surface of cathode materials.

我们回顾了我们最近对橄榄石磷酸盐正极材料 LiMPO ₄（M = Mn、Fe、Co、Ni）的表面化学和电子结构的研究。在整个金属磷酸盐正极材料系列中，已在颗粒表面检测到过渡金属离子的锂消耗和混合氧化。讨论了表面锂耗尽对光学特性和电子能带结构的影响。文献中报道的掺杂有金属或离子的LiFePO ₄有利于提高倍率能力，与未掺杂的材料相比，LiFePO ₄显示出更明显的表面锂耗尽和混合氧化。除其他外，该结果表明掺杂剂主要存在于并影响阴极材料的表面。