Hollow spherical lithium-rich layered oxide cathode material with suppressed voltage fading

Abstract

Lithium-rich layered oxide materials are very promising but with some weaknesses, which limit their commercialization, such as large irreversible capacity loss at the first cycle, continuing discharge capacity and voltage fading. Among these, voltage fading is one of the most serious problems for their final practical applications. Herein, we successfully synthesized hollow spherical Li1.2Ni0.13Co0.13Mn0.54O2 cathode material with MnO2 hollow spheres as the templates. The as-prepared sample was spherically secondary particles with hollow cavities. It showed improved cycle stability, rate capability, and suppression of voltage fading. After 100 cycles at 1 C, the retention of average discharge voltage could reach up to 97.0% (the average voltage loss was only 0.103 V). It can be attributed to the hollow structure which could release the stress of lithium removal, leading to the suppressed migration of transition metal ions into the lithium layers and the transformation from layered phase to spinel-like phase.