Decoration by dual-phase Li_2ZrO_3 islands with core-shell structures enhances the electrochemical performance of high-voltage LiNi_(0.5)Mn_(1.5)O_4

摘要

A high-voltage LiNi0.5Mn1.5O4 (LNMO) cathode was modified by Li2ZrO3 (LZO), a fast ion conductor with a unique core-shell crystalline-amorphous structure. The electrochemical results indicated a greatly improved capacity retention for LNMO-1LZO compared to LNMO. Moreover, the rate performance (100 mAh center dot g(-1)) of LNMO-1LZO at a high current density of 10 C was superior to those of pristine LNMO and other modified samples. The enhanced electrochemical performance was ascribed to the generation of dual-phase island-shaped LZO with an interior crystalline phase, which accelerated Li+ diffusion, and an exterior amorphous shell, which enhanced interfacial compatibility and stability without influencing the intrinsic spinel structure of bulk LNMO. Thus, modification with this hybrid material has the remarkable synergetic effect of enhancing interfacial Li+ diffusion and stabilizing the interfacial structure during cycling.