Gel-combustion synthesis and electrochemical performance of LiNi1/3Mn1/3Co1/3O2 as cathode material for lithium-ion batteries

Abstract

Layered structure LiNi_1/3Mn_1/3Co_1/3O₂ (LNMC) powders were synthesized by a gel-combustion method and were calcined at 750, 800, 900 and 1000 °C, respectively. The analysis of phase composition and microstructure results show that the prepared LNMC powders have the layered structure with high order level and low cationic mixing degree. As a working electrode via Li in lithium batteries, the powders calcined at 900 °C for 5 h exhibit high electrochemical performance with an initial discharge capacity of 210 mA h g⁻¹ at a current density of 40 mA g⁻¹, good cycling performance and rate capacity. Detailed X-ray photoelectron spectroscopy analysis of the LNMCs, which had been induced at various charge–discharge stages, revealed that the discharge capacities of the LNMC were mainly resulted from the redox reactions of Ni²⁺ ↔ Ni³⁺ ↔ Ni⁴⁺, and were also partially attributed to the Co³⁺ ↔ Co⁴⁺ redox couple at electrochemical potentials above 4.1 V, while Mn⁴⁺ ions were electrochemically inactive during the charge–discharge processes.