Effects of Li source and calcination temperature on the electrochemical properties of LiNi0.5Co0.2Mn0.3O2 lithium-ion cathode materials

► Instead of ammonia, oxalic acid was used as chelating agent to prepare the hydroxide precursor. ► Effects of Li source and calcination temperature on physical and electrochemical properties were investigated. ► LiCO3 was considered as a more suitable Li source, compared with LiNO3. ► The optimal calcination temperature was considered to be 850°C. ► This sample exhibited excellent discharge capacity, cycle stability and rate capability. Spherical Ni0.5Co0.2Mn0.3(OH)2 precursor was prepared via co-precipitation method using oxalic acid as chelating agent. And layered structure Li(Ni0.5Co0.2Mn0.3)O2 cathode materials were synthesized by calcining the mixture of different lithium salts and hydroxide precursor (Ni0.5Co0.2Mn0.3)(OH)2 at the temperatures ranged from 800 to 900°C. The effects of the Li source and calcination temperature on physical and electrochemical properties of the electrode samples were deeply investigated. And Li2CO3 is considered to be the suitable Li source for the synthesis of Li[Ni0.5Co0.2Mn0.3]O2. The results also show the sample calcined at 850°C gives the highest integrated intensity ratio I(003)/I(104), indicating that this sample has the lowest amount of cation mixing. At the same time, this sample shows excellent electrochemical properties, such as the largest initial discharge capacity of 176mAhg−1 at 0.1C, best cycle stability of about 100% at 0.2C and highest rate capability.