Synthesis And Properties Of Spinel LiMn₂O₄Prepared At Low Temperature

Rapid progress has been made in the research on lithium ion batteries due to its superior performance for recent years. However, these properties were greatly affected by preparation of the materials, such as the electrode and cathode materials, the selection of the electrolytes and separators, particularly the cathode materials. LiMn2O4is one of the most promising cathode materials for high voltage, low cost and non-pollution to the environment. The quality of the LiMn2O4powers strongly depends on the synthesis method and conditions. The main purpose of this paper was to explore the best method for the LiMn2O4synthesis. This paper adopted many different methods to produce the spinel LiMn2O4such as hydrothermal reaction with low reaction temperature, coprecipitation method, emulsification drying procedure.Infrared spectral analysis was utilized to qualitatively determine the compounds atoms functional group. The structure and morphology of the spinel LiMn2O4were characterized by X-ray diffraction, transmission electron microscope, scanning electron microscope and etc. The spinel LiMn2O4prepared by different synthesis conditions were studied and made into testing batteries to test the electrochemical properties of the materials.Among these methods, LiMn2O4ultrafine powders have been successfully synthesized by hydrothermal liquid former reaction with low temperature. The products showed higher degree of crystallization, stability of crystal structures, and ultrafine particles with500nm in average size. The as-synthesized products have been measured as cathode materials for lithium ion batteries with good electrochemical properties. The first discharge capacity of the cathode was130.3mAh·g-1. The specific capacity is110mAh·g-1after30cycles, only fading15.71%compared with the first discharge capacity. Experimental results showed that this method of hydrothermal liquid former reaction with low temperature can solve the problems such as particles with different sizes existing in the solid method. The system of these spinel lithium manganese acid materials for doping modification to improve its first discharge capacity and the specific capacity after many cycles was the key research subjects in the future work.