Effects of in situ-converted Li3PO4 coating on electrochemical performance of MOF-assisted LiNi0.5Mn1.5O4 cathode materials for lithium-ion batteries

A thin and uniform Li3PO4 layer was successfully converted on the surface of LiNi0.5Mn1.5O4 (LNMO) via H3PO4 pretreatment. H3PO4 was converted to Li3PO4 by reacting with the in situ Li2CO3 layer on the surface of LNMO, which was obtained by one-step calcination method based on MOFs. The in situ conversion coating strategy not only improved the tight bonding between the coating layer and the host structure but also effectively enhanced the structural stability and acid corrosion resistance of LNMO. Therein, the 1 wt% Li3PO4-coated LNMO delivered the discharge specific capacities of 107 mA h g−1 at 10 C and exhibited a capacity retention ratio of 92.86% after 200 cycles at 2 C. All results demonstrated that the in situ Li3PO4 coating layer is beneficial to improve the cyclic and rate properties of LNMO. This finding provided a simple and effective modification strategy to obtain the cathode materials for high energy density Li-ion batteries.