Preparation And Surface Coating Of Lithium-ion Battery Cathode Materials Of Limn <sub> 2 </ Sub> The O <sub> 4 </ Sub>

With the rapid development of the electronic apparatus as well as energy and environmental problems , people have put forward higher requirement to the chemical power. Lithium-ion batteries are widely used for their favorable advantages of high voltage, big specific capacity . long cycling life and litter pollution.As an important component of lithium ion battery, positive maferial becomes the focus point of research by numerous researchers.Spinel LiMn₂O₄ is considered as one of the most promising cathode materials for lithium ion battery because of its high voltage, high safety, low cost and litter pollution.This paper has analyzed the current situation of the spinel LiMn₂O₄ on the basis of summarizing lithium ion battery and the relevant materials . The deficiency of spinel LiMn₂O₄ lies in that the homogeneity of raw materials is not good, the structure is unstable, the capacity decays fast, and the circulation performance is bad. Many researchers have done plenty of researches and think that the reason causing the material capacity to decay is mainly due to the dissolving of the manganese ion in the electrolyte. Jahn-Teller effect and the resolving of the electrolyte under the high electric potential. Some researchers propose that the direct reason causing the capacity to decay and the circulation performance to worsen is that the harmful interactions between the positive materials and electrolyte.In order to improve its structural stability in the course of circulating and suppress the dissolving of manganese, people have proposed some kinds of solutions such as optimizing the synthetic craft, doping, coating, and improving the electrolyte, et al. This paper has studied the synthesis craft of spinel LiMn₂O₄ and its surface modification.We analyze the composition , structure , shape and performance of the samples with the aid of some analysis methods such as XRD.SEM, and battery performance test and examine the effect of, the conditions on the structure and performance of the materials.The result shows that the reaction conditions must be controlled strictly during the synthesis of spinel LiMn2O4 with good homogeneity and electrochemical performance.The result indicates that the layer of LiCoC>2 can reduce the contact of LiMniO4 with electrolyte and prevent the corrosion of electrolyte to LiMn2O4. The surface modification should be an effective way to improve the electrochemical performance of the positive materials for lithium ion batteries.