Study Of Physical & Chemical Properties Analytical Method Of LiMn₂O₄ Used For Li-ion Battery Cathode Material

With energy and environmental issues have become increasingly prominent, as well as the rapid development of modern technology, people request a higher demand on the performance of batteries. Lithium-ion batteries become the first choice for its high-voltage, long cycle life, high energy density, no pollution, no memory effect, and other advantages. the quality of Cathode material play a great impact on the performance of lithium-ion battery, the development of cathode materials is one of the key technologies of the development of high-energy lithium-ion batteries.The current commercialization of lithium-ion battery cathode materials have LiCoO₂, LiNiO₂, LiFePO4, LiMn₂O₄, considering cathode materials in the market, various materials have their own strengths and weaknesses.Manganese lithiumn oxides(mainly for the spinel LiMn₂O₄) have the following benefits:low price, easy preparation, and manganese is rich in resources, the environment pollution-free, even if LiMn₂O₄ has a poor cycle , high temperature capacity easily decay, but a more comprehensive comparison LiMn₂O₄ high cost-effective, is recognized as the most competitive of the lithium-ion battery cathode materials in the 21st century.This paper first reviewed research progress of lithium-ion battery cathode materials spinel LiMn₂O₄ at home and abroad, mainly concentrating in the study of synthesis and doping modified,and then briefly introduced the main analysis method - atomic absorption spectrometry . This paper focused on two parts: First, the physical performance analysis of lithium-ion battery cathode materials LiMn₂O₄; Second, the chemical composition analysis of lithium-ion battery cathode materials LiMn₂O₄. Analysis of the physical properties of LiMn₂O₄ concluded pH, particle size distribution, surface area, tap density, crystal structure, water content ,the Analysis values of LiMn₂O₄ were in line with pre-specified values. the chemical composition analysis of LiMn₂O₄ major for the determination of contents of Mn,Fe,Na,Ca,Mg,Pb,Cd. The method of determination of Mn is complex titration, the key is accurate preparation for the concentration of EDTA standard solution ,as well as the indicator can clearly instruct titration end, the method is accurate, content of Mn is 53.78 percent , compared with the 54.9 percent of the value of equipment determination that allowed in the Measurement error, a high precision with RSD = 2.04%. Determination of Fe, Na, Ca, Mg by FAAS, the main issues to be considered were: (1)Selecting the concentration of hydrochloric acid in the standard solutions and sample solutions of Fe, Na, Ca, Mg was from two aspects of sensitivity and equipment protection. (2)Whether the matrix Mn and Li have an impact on the determination of Fe, Na, Ca, Mg, it would have to add equivalent amount of Mn and Li of sample solutions in the standard solutions. (3)It was necessary to add ionization buffer CsCl in Na measurment, ionization buffer could reduce the loss of ionization of Na ,it also increased measurement sensitivity and accuracy. (4)It need to add releasing agent LaCl3 in Ca, Mg measurment,the releasing agent could basically eliminate interferences of impurities and other elements and enable the examination to have a higher accuracy. Determination of Pb, Cd used graphite furnace atomic absorption spectrometry, the main issues to be considered were nitrate concentrations, Pb and Cd ashing and atomization temperatures, the impacts of matrix modifiers on the determination of Pb and Cd. In accordance with analysis results of LiMn2O4 materials, The analysis methods of LiMn2O4 chemical composition established in this paper were accurate and precise, meeting the requirements of such material.