Preparation And Property Study Of Layer-spinel Manganese-based Cathode Material

With deterioration of the environment and depletion of the energy, lithium ion battery has been widely concerned. The batteries, no matter the initial cadmium nickel battery or popularly used lithium ion battery, are all designed to meet the demand of higher capacity, faster charging speed and more secure. Lithium-rich manganese cathode got the favour of the researchers because of its high specific capacity, but its first irreversible capacity is too high and rate capacity is too poor. These inferior performances seriously hinder Lithium-rich manganese cathode on the road of commercialization.In order to improve the performance of lithium-rich manganese cathode material, a new type of non cobalt lithium-rich manganese layered-spinel cathode material was proposed in this experiment. The specific capacity is further improved through the preparation of nano sized materials. The introduce of spinel material is beneficial to the rate capacity of lithium-rich manganese cathode without sacrificing the specific capacity.In addition, the material has a positive effect on the cost and environment for abandon of cobalt and nickle. By comparing with the traditional materials, the discharge capacity of new material improves 50.7 mA·h/g at 0.1 C and 73.7 mA·h/g at 5 C.To explore the influence of new material synthesis conditions on its performance,the heating temperature and holding time on precursor synthesis were studied in this experiment. Comparing the effects of different heating temperature and holding time on precursor synthesis, 200℃ as heating temperature and 20 h as holding time are the optimum parameters. The calcination temperature and calcination time on cathode synthesis was studied. The optimum calcination temperature is 600℃ and the optimum calcination time is 10 h. The content of spinel structure in the material also has an important effect on the properties of materials, and it is found that the best ratio of Li2MnO3 to LiMn2O4 is 7:3. Under the optimum experimental conditions, the discharge capacity of the cathode is 244.5 mA·h/g at 0.1 C and 170.9 mA·h/g at 5 C.