Highly stable and high-performance MgHPO4 surface-modified Ni-rich cathode materials for advanced lithium ion batteries

Abstract

A Ni-rich layered cathode (LiNi_0.8Co_0.1Mn_0.1O₂, NCM) is a highly promising cathode material for lithium-ion batteries (LIBs). However, LIBs face crucial challenges of its structural degradation and interfacial instability during the cycling process. In this paper, we successfully design a Mg-doped and Li₃PO₄-coated NCM cathode material. The electrochemical results reveal that MgHPO₄-modified NCM shows not only an advanced initial discharge capacity of 203.5 mA h g⁻¹ but also the highest rate capability of 89.4% at 6.0C. More importantly, MgHPO₄-modified NCM maintains a superior cycling performance of 86.3% after 100 cycles at 25 °C. Most importantly, MgHPO₄ dual-modification on the NCM particle can immunize against the phase transition from the layered phase to the rock-salt phase. Therefore, this study proposes a novel strategy for improving the NCM cathode material to accelerate its commercialization.