| Energy is the most important factor restricting the development of social economy,and with the progress of science and technology,social and economic development with the continuous,but also brought the energy crisis continues to intensify and damage to the ecological environment and other negative effects,in order to make Social and economic higher,faster and better development,the development of green new energy-saving materials is imperative.With the continuous upgrading of electronic products,all kinds of electric vehicles continue to develop,lithium-ion secondary battery has become the focus of research object.With high capacity LiNi0.8Co0.1Mn0.1O2 cathode material is more popular,but its cycling peiformance and high temperature storage performance still need to be further improved.In this paper,LiNi0.8Co0.1Mn0.1O2 was selected as research subjucts.In order to improve the electrochemical properties of the above materials,sintering process and modification such as the bul doping and surface coating was investigated.According to the thermogravimetric analysis,the LiNi0.8Co0.1Mn0.1O2 cathode material with lamellar structure was prepared by high temperature sintering method.The effects of different sintering temperature,sintering time and lithium content on the properties of the composites were discussed.The results show that the sintered temperature is 820 ?,the sintering time is 12h and the lithium content is 1.02 that the synthesized LiNi0.8Co0.1Mn0.1O2 cathode material has the most stable structure and electrical properties.Its initial discharge capacity of 0.1C is 203.1mAh/g,after 50cycles,capacity retention rate of 82.24%.The effects of Al and Zr on the structure and electrochemical properties of LiNi0.8Co0.1Mn0.1O2 cathode materials were investigated.XRD results show that all the samples have good hexagonal ?-NaFeO2 lamellar structure.The electrochemical performance test showed that the first discharge capacity,the first discharge efficiency,and the magnification performance were not significantly different from those of the undoped material,but the cycling stability was improved,and the capacity after 50 times The retention rate has been significantly improved,and the doping content of 2%when the performance to achieve the best.While the doping amount of 2%of the Zr element doping is superior to other materials,its first discharge specific capacity of 0.1 C is 202.7mAh/g,the first discharge efficiency is 90.3%,after 50cycles,capacity retention rate of 91.42%.The effects of Al2O3 and TiO2 on the structure and electrochemical properties of LiNi0.8Co0.1Mn0.1O2 cathode materials were investigated by solid phase method.XRD results show that the coated material does not change the structure of the material.SEM,TEM analysis showed that the surface of the cathode material coated with a layer of uniform oxide film.The electrochemical performance of LiNi0.8Co0.1Mn0.1O2 cathode was the best,and the cycling performance and storage performance of Al2O3-coated material were better than that of the other Coated and coated with TiO2.The capacity of the first discharge is 201.2 mAh/g at the voltage of 3.0-4.3V and 0.1C,and the capacity retention rate is 93.25%at 1C magnification after 50 cycles of normal temperature.After the high temperature cycle is 50 times,the discharge rate is 1C When the capacity retention rate of 76.45%. |
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