Synthesis and Characterization of Gradient Cathode Material for Lithium-Ion Batteries

Abstract

Gradient cathode material of LiNi 0.7 Co 0.15 Mn 0.15 O 2 was synthesized by mixing hydroxide co-precipitated precursors with 8% excess LiOH•H 2 O. Structure and electrochemical properties of the material was characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), galvanostatic charge-discharge test and electrochemical impedance spectroscopy (EIS). The results indicate that the typical crystal of the material is α-NaFeO 2 . The particles are formed by 200nm~500nm crystals. The gradient material sintered at 800°C shows the best electrochemical performance, the initial discharge capacity of the material is 164.45mAh•g -1 at 0.2C, its discharge capacity retention of 86% at 2C and with lower electrochemical impedance.