Enhanced electrochemical performance of single crystalline LiNi0.8Co0.1Mn0.1O2 cathode via LiMn0.5Fe0.5PO4 particle coating

Single crystalline Ni-rich NCM cathodes are promising candidates for next-generation lithium ion batteries due to their high energy density and potential for improved cycling stability. However, their practical application is still limited by surface degradation phenomena, including electrolyte-induced side reactions and formation of surface reconstruction layers, which are particularly exacerbated under a high voltage operation. In this study, we investigate the effect of carbon-coated lithium manganese iron phosphate (C@LMFP) particle coating on the electrochemical performance of Ni-rich NCM cathode, with a particular emphasis on the composite fabrication method and role of carbon coating on LMFP. The results demonstrate that C@LMFP-coated NCM cathode fabricated via ball milling exhibits higher discharge capacity and enhanced cycling stability. This performance improvement is attributed to the intimate interfacial contact achieved through ball milling, which suppresses the surface side reactions and mitigates the phase transformation from layered structure to rock-salt phase. In addition, the conductive carbon layer on LMFP facilitates the electronic transport at the interface. These findings highlight the importance of both effective interfacial integration and carbon-assisted conductivity in stabilizing single crystalline Ni-rich NCM cathodes under aggressive high voltage conditions, offering a viable strategy for high performance cathode design. • C@LMFP particle coating is introduced on the single crystal NCM811 by a ball milling. • C@LMFP coated NCM exhibits the high discharge capacity and improved cycle stability. • Parasitic side reactions and formation of reconstruction layer are highly suppressed. • Carbon on LMFP contributes to the better electronic transport between NCM and LMFP.