| The serious problems in the aspects of energy resources, environment, and the rapid development of modern science and technology require that the batteries have the high performance. The Lithium ion batteries (LIB) are regarded as the best one, because they have high working voltage, long cyclic life, high energy density and no environmental pollution.The cathode materials have great influences on the performance of LIB. Nowadays, the cathode material used in the commercial LIB is LiCoOi. But cobalt is expensive, it makes serious environmental pollution and the resource of it is limited. The price of LiMn2O4 is cheap and it is easily to be prepared. The resource of manganese is rich and has no environmental pollution, but the specific charging-discharging capacity is lower and the cyclic performance of it is also worse, especially at high temperature. The resource of nickel is richer than cobalt. The price of LiNiO2 is cheap, its specific charging-discharging capacity is high and it has no environmental pollution, but it is difficultly to be synthesized. The structure of it is unstable, which will cause the decrease of the specific charging-discharging capacities. The thermal stability of it is bad. According to the above conditions, we have studied the cathode materials LiNi1-xMxO2(M=Co, Al, Mn) on the basis of studying LiCoO2 and LiNiO2.LiCoO2 was synthesized by solid stale coordination reaction method. The process was analyzed by DTA and TG. The phase structure, appearance and size of LiCoO2 powder were characterized by XRD and SEM. The influences of preparation conditions on the structure of the product were discussed. The experimental results show that the reaction temperature and reaction time have great influences on the structure of the product, in the aspects of synthetic temperature, calcination temperature and granularity distributions, the solid state coordination reaction method is better than the traditional high temperature solid stale reaction method.LiNiO2 was synthesized by the high temperature solid state reaction. The structure was determined by XRD and the appearance of LiNiO2 power was characterized by SEM. The influences of preparation conditions such as raw materials, the mole ratio of Li/Ni, the sintering atmosphere, the sintering temperature and the reaction time on the structure and electrochemical performance of the product were discussed. The synthetic technology was optimized. In air Li2Ni8O10 phase can be synthesized, but LiNiO2 can be obtained only in O2, the electrochemical performance of LiNiO2 is evidently better than that of LiNi8O10. For synthesizing LiNiO2 of good electrochemical performance, a little excess of lithium, keeping temperature at 600℃ for 3h and 700℃ for 8 h are necessary. At the temperature, the reaction rate is slow, at high temperature, it is difficult to control the particle size of the product. The preheating step in the synthesis solves this problem. The failure to synthesis LiNiO2 by solid state coordination method was analyzed.The spherical Ni(OH)2 was selected as the nickel resource to maintain the spherical shape of the particles in the product and to increase the specific charging-discharging capacities. LiNO3 was selected as the lithium resource, since NO2 and O2 appearing during the decomposition at low temperature have strong oxidation property. A little excess lithium is needed. CoO was selected as the resource of cobalt. LiNi1-xCoxO2 was synthesized in air, keeping temperature at 300 for 4 hours and at 800℃ for 8 hours, the XRD analysis shows that the synthetic power of LiNi1-xCoxO2 crystallizes perfectly, which has a normal layer structure of alpha-NaFeO2. The SEM analysis shows that the power particles are spherical diameters of power particles are about 10 urn. The influences of preparation conditions, such as raw-materials, the mole ratio of Li/Ni. the sintering temperature and the reaction time on the structure and electrochemical performance of the product were discussed. The synthetic technology was optimized. With the in...
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