Enhancing the Electrochemical Performance of High Voltage LiNi(0.5)Mn(1.5)O(4) Cathode Materials by Surface Modification with Li(1.3)Al(0.3)Ti(1.7)(PO(4))(3)/C

A novel method for surface modification of LiNi(0.5)Mn(1.5)O(4) (LNMO) was proposed, in which a hybrid layer combined by Li(1.3)Al(0.3)Ti(1.7)(PO(4))(3) (LATP) and carbon (C) composite on LNMO material were connected by lithium iodide. Structure and morphology analyses illustrated that a higher contact area of active substances was achieved by the LATP/C composite layer without changing the original crystal structure of LNMO. XPS analysis proved that I(−) promoted the reduction of trace Mn(4+), resulting in a higher ion conductivity. Galvanostatic charge–discharge tests exhibited the capacity of the LNMO with 5% LATP/C improved with 35.83% at 25 °C and 95.77% at 50 °C, respectively, compared with the bare after 100 cycles, implying the modification of high-temperature deterioration. EIS results demonstrated that one order of magnitude of improvement of the lithium-ion diffusion coefficient of LATP/C-LNMO was achieved (3.04 × 10(−11) S cm(−1)). In conclusion, the effective low-temperature modification strategy improved the ionic and electronic conductivities of the cathode and suppressed the side reactions of high-temperature treatment.