LiMnPO4 surface coating on LiNi0.5Co0.2Mn0.3O2 by a simple sol-gel method and improving electrochemical properties

Recently, cathode materials based on LiNi0.5Co0.2Mn0.3O2 are being widely investigated for application in lithium ion batteries (LIB). However, the cycle performance of this material needs to be enhanced. The surface coating modification is a feasible option to further improve the electrochemical properties of the material. In this paper, a simple sol-gel method was used to prepare a LiMnPO4 (LMP) coating with a thickness of about 25 nm on the surface of LiNi0.5Co0.2Mn0.3O2 (denoted as NCM523-LMP). As a cathode material for lithium ion batteries, NCM523 coated with 3 wt% LMP showed good cycle performance as well as improved thermal stability. The coated sample exhibited improved cycle stability (200 cycles, 136.8 mAh g−1) and high temperature cycle performance (55 °C, 200 cycles, and 125.2 mAh g−1). This significant enhancement can be attributed to the strengthening of surface structure and effective isolation from harmful side reactions between the material and electrolyte. The LMP coating modified NCM523 shows potential as a high-performance cathode material for LIB.