Sol–gel preparation of Li-rich layered cathode material for lithium ion battery with polymer polyacrylic acid + citric acid chelators

Abstract

The sol–gel method was improved to synthesize the layered Li-rich cathode material Li1.2Ni0.13Co0.13Mn0.54O2 by employing the mixture of polymer polyacrylic acid (PAA) and citric acid as the mixed chelator. The crystal structure, particle morphology and electrochemical performance of the prepared layered Li-rich cathode material are extensively studied by X-ray diffraction spectrometry, scanning electron microscopy, charge–discharge test, cyclic voltammetry and electrochemical impedance spectroscopy techniques. The results show that the Li-rich cathode materials prepared with the new method present explicit layer structure, low level of Li+/Ni2+ disordering, large specific surface area and accurate chemical composition. When measured with electrochemical test system, the prepared material exhibits a high capacity of 274.8 mAh g−1. The excellent performances of the prepared material could be ascribed to the fact that the novel approach combines the advantages of the two chelating agents of PAA and citric acid.