Structure Control Of Phosphate Nanomaterials For Lithium-ion Batteries

With the increasing requirement for major scale electric energy storage,electrical transportation and electrical tools,investigators are handing over more and more attention on the development of rechargeable energy-storage devices with high safety performance,long cycle life,and high energy and power density.There is needless to say that Li-ion battery skill has played an especially important part among the developed technologies.To date,LiMPO4?M=Fe,Mn,Co and Ni?is one of the widely used cathode materials in commercial Li-ion batteries owing to its excellent electrochemical properties and facile preparation process.In this work,LiMPO₄ nanomaterials were prepared by hydrothermal,solvothermal and spray drying technique.The structure,morphology and electrochemical properties of LiMPO₄ were studied by XRD,SEM,EDS and electrochemical performance tests.Hydrothermal prepared monodisperse LiFe_xMn_1-xPO₄ nanosheets have good cycling stability,When x=0.2,the electrochemical performance of the material is successfully improved,After 300 cycles,the capacity retention of LiFe0.2Mn0.8PO4 nanosheets is still above 95%.The carbon-coated LiFe0.2Mn0.8PO4 nanosheets prepared by the solvothermal method have higher specific discharge capacity and better cycling stability with the specific discharge capacity maintained at about 75 mAh·g^-1 for 200 cycles.LiFePO₄/C nanospheres synthesized by spray drying method were added appropriate amounts of dopamine and urea in the synthesis process to adjust the calcination temperature.When the calcination temperature was 700?,the initial discharge specific capacity of LiFePO₄/C nanospheres synthesized after mixing dopamine reached 156 mAh·g^-1 at 0.1 C,and the capacity retention rate is 83.3%after 150 cycles.