Enhanced electrochemical performances of Ni-rich cathode materials for lithium ion batteries by mixed coating layers

Abstract

The properties exhibited by Ni-rich cathode materials were enhanced through the mixed coating layers of Li3PO4 and boric acid. The scanning electron microscopy (SEM), the transmission electron microscope (TEM), the differential scanning calorimetry (DSC), the Electrochemical Impedance Spectroscopy (EIS), as well as the half-cell and full-cell charge-discharge tests were adopted for characterizing the structure and electrochemical properties exhibited by the cathode materials. As revealed by results, the Li3PO4 and boric mixed coating layers can effectively reduce the surface area and protect the direct contact between cathode material particle surface and electrolyte, meanwhile improving the structural stability and cycle performance. The coating of fast ionic conductor contributes to enhance the specific capacity possessed by the Ni-rich cathode materials accordingly.