Stabilization of LiV3O8 Rod‐like Structure by Protective Mg3(PO4)2Layer for Advanced Lithium Storage Cathodes

LiV3O8 material with high discharge capacity has attracted increasing attention as cathode material for lithium‐ion batteries (LIBs). However, LiV3O8 is still limited by its weak dissolution and change of lattice structure. In this study, Mg3(PO4)2 fully coated LiV3O8 nanoparticles are successfully prepared by rheological phase reaction and surface deposition. The thickness of Mg3(PO4)2 coating layer is estimated to 24.7 nm for surface‐modified LiV3O8 with Mg3(PO4)2 content of 1.0 wt.%. The as‐prepared Mg3(PO4)2 coated‐LiV3O8 is utilized as cathode and showed high initial capacity of 323.93 mAh g−1. In addition, it maintained stable capacity of 250.82 mAh g−1 after 50 cycles at the current rate of 60 mA g−1 between 1.8 and 4.0 V. This value was much higher than that of bare LiV3O8. Besides, even at current density of 240 mA g−1, its capacity keeps 170.89 mAh g−1 after 50 cycles. The detailed quantitative kinetics analyses confirm the fundamental reasons behind the enhanced rate capability and cycling stability. Overall, this work opens up novel avenues towards the design of protecting cathode materials, which could broaden applications of insoluble phosphates.