| Lithium ion battery has been widely used in more and more fields because of its high operating voltage, high energy density, large capacity, long cyclic life and high thermal stability since its first commercialization in 1991.Ultrafine Co3O4 material is the most important cobalt source of the cathode material LiCoO2 in lithium ion battery. The purity, particle size, morphology of ultrafine Co3O4 plays a very important role in the obtained LiCoO2 material. Searching for an easy method to prepare ultrafine Co3O4 with good morphology, uniform particle size will be valuable in production. Meanwhile, a lot of researchers have reported that nano-sized Co3O4 material was a promising anode material of lithium ion batteries with high capacity. Few works have been done to investigate the electrochemical properties of micron-sized Co3O4 anode material. It will be valuable to take some electrochemical tests of the obtained ultrafine Co3O4 material. In this paper, works have been done as the followings.Firstly, the liquid-precipitation method is widely used to prepare inorganic materials in industrial production, which presents as an easy, low cost and high yield way. In this paper, we have prepared ultrafine Co3O4 material, with fine morphology, uniform particle size and high tap density, by liquid-precipitation method. The ammonia is used as complexant, and the surfactant is used as dispersant. The synthesizing conditions such as different precipitators, temperature of calcinations, pH of the system and different dispersants were discussed. Corn cob structure ultrafine Co3O4 material was obtained by oxalate precipitation process, introduce PEG10000 as dispersant. The electrochemical tests showed the corn cob structure Co3O4 anode material had a high initial reversible specific capacity of 896.8 mAh/g, and a good capacity retaining ability, which is better than those micron-sized Co3O4 anode materials reported before. Similar spherical ultrafine Co3O4 material was prepared by alkaline carbonate process, with PVA (Poly vinyl alcohol) dispersant. Compared with three other industrial products, the similar spherical ultrafine Co3O4 material exhibited the best on its tap density, particle size, dispersancy, and particle morphology as well. By the further research, the spherical ultrafine Co3O4 material can be used as cobalt source of spherical LiCoO2 material for industrial application. However, as an anode material of lithium ion battery, the spherical Co3O4 material showed an initial reversible capacity of 621.8 mAh/g. Both of the capacity retaining and the large current charge-discharge ability were very poor.Secondly, we synthesized polyhedron Co3O4 material by sol-gel method with triblock copolymer surfactant P123 (EO20PO70 EO20) used as the medium for the first time. The electrochemical tests showed the polyhedron Co3O4 had an initial reversibly capacity of 643.9 mAh/g. Then we added 1.0%, 0.8%, 0.6%, 0.4%, 0.2% (mol %) of SnCl2 into the reaction system, and obtained different quantity tin doped Co3O4 materials. The SEM photos proved that the tin doped Co3O4 materials remained polyhedron morphology, and the XRD pattern showed the productions had typical spinel Co3O4 structure. The electrochemistry test indicated the 0.8% tin doped sample showed the best remaining capacity.
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