Combustion synthesis of LiNi_1/3Co_1/3Mn_1/3O₂ powders with enhanced electrochemical performance in LIBs

The layer-structured LiNi_1/3Co_1/3Mn_1/3O₂ (NCM) cathode material for LIBs with diameter of 200-400 nm was successfully synthesized by combustion method using glycol as solvent and fuel at 450 °C, followed by calcinations at 850 °C for 10 h. The obtained powder showed an initial discharge capacity of 160.2 mA h/g and the capacity could remain 90.5% at 0.5 C after 50 cycles, better than other two samples obtained by co-precipitation and sol-gel methods with similar morphology and stoichiometric ratio. Controlled experiments were carried out by adding different combustion improvers of tartaric acid, glycine, and citric acid into the combustion system, respectively. The powder showed much enhanced performance by adding tartaric acid with initial discharge capacity of 185.9 mA h/g and capacity retention of 95.4% at 0.5 C after 50 cycles. It could be mainly ascribed to the added tartaric acid with higher enthalpy of combustion and better dispersion in the solvent, leading to better layered structures and smaller sizes of the sample.