Solvent, Concentration and Temperature Effects in LiNi_0.5Mn_1.5O₄‐Li₃PO₄ Coating Processes

Abstract The spinel material LiNi_0.5‐xMn_1.5+xO₄ (LNMO) represents a very promising cathode candidate due to its high operating voltage and high specific capacity. Unfortunately, this material is suffering from capacity degradation and a low degree of cyclability at normal and elevated temperatures. Herein, using hydrogen peroxide (H₂O₂) as an activating reagent, an improvement of the spinel electrochemical properties is achieved by coating the spinel with Li₃PO₄. The coating method is simple, has a low cost, it could be done in both organic or water solutions, and results in homogeneously coated particles. The structure and the electrochemical properties of the prepared cathodes were probed using XRD, SEM, EDS and electrochemical studies. It was established that the coating has a positive effect on the stability and performance of LNMO. As result, a long cycling stability and very good rate performance (~99 % capacity retention over 300 cycles at 1 C) was achieved.