| Intensive research and development work was being conducted to further improve the performance of lithium ion batteries and reduce the cost of electrode materials. LiCoO2 has been widely used as cathode material in commercial lithium ion battery production. But, due to the high cost of LiCoO2, many efforts have been made to replace it. On the base of reviewing the development of cathode materials for lithium ion batteries, this dissertation emphasizes on the preparation of layered LiNi1/3 Co1/3 Mn1/3 O2 cathode materials possessed superior performance by the technology of spray pyrolysis. The synthesis, doping, electrochemical behavior of layered LiNi1/3 Co1/3 Mn1/3 O2 cathode materials were studied in detail.The effect of the main controlled condition in the process of spray pyrolysis, such as solution type,solution concentration,the flow rate of carrier gas,pyrolysis temperature on morphology, size of particles, tap density of oxide of nickel-cobalt-manganese precursor were studied firstly. Then the effect of precursors synthesis, heat treatment, Li/M(M=Ni+Co+Mn) molar ration on morphology, lattice parameter, and electrochemical performance of layered LiNi1/3 Co1/3 Mn1/3 O2 were studied. On this basis, the optimized flowsheet was obtained, i.e. oxide of nickel-cobalt-manganese precursor was prepared by spray pyrolysis method with nitrate solution as precursor, and mixed with Li2CO3 ( Li/M ration of 1．05) , then the mixture powders were calcined at 950℃for 16h.The results showed that the initial discharge capacity of LiNi1/3 Co1/3 Mn1/3 O2 cell was 138．3 mAh/g in 3．0-4．2V and at 1C rate. Its capacity retained 94．36% after 50 cycles. Its performance was close to that of the commercial material. So this material was determined to be a promising cathode material for lithium ion batteries.Layered LiNi1/3 Co1/3 Mn1/3-xMxO2 (M=Mg, Al) cathode materials were synthesized by spray pyrolysis method. The results showed thatLiNi1/3 Co1/3 Mn1/3-xMxO2 (M= Mg2+,Al3+, x=0．02) exhibited respectively the initial capacity of 138．0 mAh/g, 143．1 mAh/g in the voltage range of 2．75-4．3V and at 1．0 C rate, its capacity retained 98．4%, 97．1% after 50 cycles, Layered LiNi1/3 Co1/3 Mn1/3 O2 cathode material was modified by doping element with F. The results indicated that the cycle performance at high voltage were improved by F doping, and the reason has been analyzed from structure of cathode materials. LiNi1/3 Co1/3 Mn1/3 O2-yFy (y=0．05) doped by F exhibited the specific capacity of 134．1 mAh/g after cycling 50 times at room temperature.The formation mechanism of particle structure in the process of spray pryolysis and the effect of the main factor on particle morphology were simply introduced.
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