Study On Preparation Of Micro-Nano-Porous Lithium Iron Phosphate And Electrochemical Characteristics Of Micro-Nano-Porous Lithium Iron Phosphate-Graphene Oxide Composite Electrode Materials

Now,new energy lithium-ion power batteries still have fatal defects,such as low energy density?short cruising range?,poor rate of charge and discharge performance?long charging time?,and poor safety.Electrode material is a key factor that affects battery performance.The particle size,structure,specific capacity,electrical conductivity,and Li⁺'s mobility of the electrode material determine the performance of the power battery.Study on preparation of micro-nano porous LiFePO₄ to obtain higher effective Li⁺concentration on LiFePO₄ battery electrode materials by solid-phase reaction method and sol-gel method.Then,prepare high energy density and high conductivity composite lithium ion battery electrode material by use GO of high conductivity by research group.The effects of the adding type and content of flux and the reaction factor on the phase purity and morphology of the LiFePO₄ were studied in the solid-phase reaction method.The effects of the dispersant and sintering factor on micro-nano porous LiFePO₄ morphology were studied in sol-gel method.The relationship between GO content and conductive properties were studied in micro-nano porous LiFePO₄/GO composite electrode materials.The main research content is as follows:1.Micro-nano porous LiFePO₄ powder was synthesized of FeSO₄·7H₂O,LiCO₃,NH₄H₂PO₄,NH₃·H₂O,NaOH and flux?A?by solid phase reaction method in 500?/1h.The powder particles have good dispersibility,the particle size is about100nm²00nm,and the size is uniform;2.Micro-nano porous LiFePO₄ powder was synthesized with urea as a dispersant by sol-gel method in 500?/1h.The powder particles have good dispersibility,the particle size is about 50nm¹50nm,and the size is uniform;3.The GO does not change the phase of LiFePO₄.The GO addition improves the AC/DC conductivity of electrode materials and the specific discharge capacity at 0.1C.