FACILE SOL–GEL SYNTHESIS OF Li[Li 0.2 Mn 0.56 Ni 0.16 Co 0.08 ]O 2 AS IMPROVED CATHODE MATERIAL FOR LITHIUM-ION BATTERIES

Li[Li0.2Mn0.56Ni0.16Co0.08]O-2 cathode materials for Li-ion batteries were synthesized by a facile solgel method followed by calcination at various temperatures (700 degrees C, 800 degrees C and 900 degrees C). Lithium acetate dihydrate, manganese (II) acetate tetrahydrate, nickel (II) acetate tetrahydrate and cobalt (II) acetate tetrahydrate are employed as the metal precursors, and citric acid monohydrate as the chelating agent. For the obtained Li[Li0.2Mn0.56Ni0.16 Co-0.08]O-2 materials, the metal components existed in the form of Mn4+, Ni2+ and Co3+, and their molar ratio was in good agreement with 0.56 : 0.16 : 0.08. The calcination temperature played an important role in the particle size, crystallinity and further electrochemical properties of the cathode materials. The Li[Li0.2Mn0.56Ni0.16Co0.08]O-2 material calcined at 800 degrees C for 6 h showed the best electrochemical performances. Its discharge specific capacities cycled at 0.1 C, 0.5 C, 1 C and 2 C rates were 266.0 mAh g(-1), 243.1 mAh g(-1), 218.2 mAh g(-1) and 192.9 mAh g(-1), respectively. When recovered to 0.1 C rate, the discharge specific capacity was 260.2 mAh g(-1) and the capacity loss is only 2.2%. This work demonstrates that the solgel method is a facile route to prepare high performance Li[Li0.2Mn0.56Ni0.16 Co-0.08]O-2 cathode materials for Li-ion batteries.