The formation and electrochemical property of lithium-excess cathode material Li1.2Ni0.13Co0.13Mn0.54O2 with petal-like nanoplate microstructure

Abstract

Lithium-excess oxide shows great potential for its high specific capacity of exceeding 280 mAh g−1. However, the poor rate capability caused by the poor electrochemical kinetics condition as well as the structure instability block the way of its application. Here, we aimed to improve the kinetics circumstance for lithium ion transference through the material bulk by synthesizing lithium-excess oxide with high specific surface area. Petal-like nanoplates and nanoparticles with excellent electrochemical performance were obtained at different sintering temperatures and times by the electrospinning-sintering method, which facilitates the sufficient contact of electrode and electrolyte and helps to reduce the polarization during the electrochemical reaction process. Cyclic voltammetry tests verify that a portion of oxidized oxygen is reduced reversibly at 3.0 V and the reduction of oxygen contributes to the discharge capacity. Electrochemical impedance spectroscopy plots illustrate the ameliorative electrochemical kinetics is conductive to the oxidation of oxygen at 4.5 V.