Synthesis,Modification And Electrochemical Properties Of Lithium Iron Manganese Phosphate

With the development of society,environmental pollution generated by the combustion of fossil fuels,such as greenhouse effect caused by carbon dioxide,global warming,melting glaciers and other problems have cropped up.With non-renewable fossil energy consumption,energy shortage has become a serious problem.The efforts have been made in lithium-ion battery systems because of its high energy density,relatively simply reaction mechanism.In the past 20 years,the lithium-ion battery technology has been very quickly and widely used in portable electronic products.However,there are still some problems about cycling performance and safety performance used in large-scale,high-energy systems such as hybrid electric vehicles or electric vehicles.Therefore,further efforts continued on the lithium-ion battery materials are very necessary.Because of the low cost,environment-friendly,high-performance,and its high security of theoretical capacity,stable voltage platform,lithium iron manganese phosphate cathode material is one of the ideal future lithium-ion battery cathode materials,but its development was limiting by its low conductivity and lithium ion low diffusion rate,this paper was optimized the synthesis of the material to improve the electrochemical properties.The main points are as follows:(1)Li2CO3?FeC2O4?Mn(CH3COO)2·4H2O?NH4H2PO4 as the starting materials,citric acid as the carbon resource,the LiMn0.5Fe0.5PO4/C were synthesized by a high-temperature solid-phase method.The target materials were detected in the structure and morphology.The materials were to be studied by specially capacity,cycle performance,and electrochemical impedance test,respectively.(2)Li(CH3COO)?FeSO4·7H2O?Mn(CH3COO)2·4H2O?NH4H2PO4 as the starting materials,citric acid as the carbon resource,the LiMn0.5Fe0.5PO4/C were synthesized by a sol-gel way.The target materials were detected in the structure and morphology.The materials were to be studied by specially capacity,cycle performance,respectively.CNTs were mixed in,explore its effects to the electrochemical properties of materials.(3)Li3PO4,LiH2PO4,Mn(CH3COO)2·4H2O,Fe3(PO4)2·8H2O as the starting materials,glucose and citric acid as the carbon resource,respectively,the LiMn0.5Fe0.5PO4/C were synthesized by a high-temperature solid-phase method.The target materials were detected in the structure and morphology.The materials were to be studied by specially capacity,cycle performance,and electrochemical impedance test,respectively.