| Lithium ion battery is used widely because of its high operating voltage, high energy density, large capacity and long cyclic life. The duality solid solution of LiCoxNi1-xO2 is becoming the hot topic of research on the cathode materials now.In this paper, a new synthetic method, sol-gel auto-combustion presintering method, was used to synthesize LiCoxNi1-xO2 as cathode material for lithium ion battery. The effects of synthesis method, chemical doping and modification on the structure and capacity of LiCoxNi1-xO2 were investigated by means of XRD, TG-DTA, SEM, ICP and electrochemical techniques. The main results are as follows:(1) The effects of a chelating agent and its dosages, the ratio of chelating agent to metal on the structures and capacities of the products LiCoxNi1-xO2 were studied. The results showed that citric acid as a chelating agent can react with carbonate salt of lithium, cobalt and nickel to form polymer gel. When the concentration of citric acid is 2mol/L and the ratio of citric acid-to-metal is 1.25, the products of LiCoxNi1-xO2 have optimum hexagonal structures, the distribution of its granularity is narrow with the range of 10 and 130μm, D50 is 44.4μm and D90 is 69.3μm. The initial discharge capacity is 158.7mAh·g-1.(2) The thermal characteristics and decomposition activation energies during the synthesis process of dry gel LiCoxNi1-xO2 were studied by thermal analysis and Doyle-Ozawa, respectively. The results showed that the composition process of dry gel include four steps: the removal of absorbed water, buring of organic citric acid, discomposite of citric acid salt and the form of final product LiCoxNi1-xO2. The decomposition activation energy of each step calculated by Doyle-Ozawa is 97.8 kJ/mol, 127.4 and 140.4 kJ/mol, 118.7 kJ/mol, 105.2 kJ/mol, respectively.(3) The sol-gel auto-combustion presintering emethod has great effect on the structures and properties of LiCoxNi1-xO2. The gel of LiCoxNi1-xO2 were first pre-...
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