Preparation Of Phosphates As Cathode Material For Lithium-Ion Battery By Electrospinning

With the continuous progress of science and technology, energy andenvironmental problems have become more and more serious, which put higherrequirements forward to the battery industry.Lithium-ion batteries are very popularbecause of their good battery performance and environmentally friendlycharacteristics.Now the major restriction of lithium-ion batteries'development is thecathode material. Phosphate cathode materials draw widely attention to people withtheir good electrochemical performance,structural stability,safety,low price andattracted. However,Phosphate cathode's electronic conductivity and ionicconductivity were low, which is a major obstacle to its further development.In this paper, I will give an overview of lithium ion batteries and have a reviewof lithium-ion batteries cathode materials'development situation and problems indetail. I studied the technological conditions of using the method of electrospinning tomanufacture phosphate lithium-ion battery cathode materials.And used the method ofSEM,XRD and electrochemical tests to inspect the microcosmic surface,the crystalstructure and electrochemical performance of the gotten LiFePO₄/C andLi₃V₂(PO₄)₃/C materials .I have gotten the nanometer materials of LiFePO₄/C and LiFePO₄/C doped withgraphite by electrospinning method. By adjusting the content of mineral salt andPVP,I have confected different kinds of precursor liquid and obtained different kindsof spinning materials.According to the SEM test outcome of sintering materials, theamount of PVP plays a very important role in maintaining the material's stickmorphology.First,doping graphite can speed up the speed of the spinning. Besides,doping graphite materials'stick morphology was no longer apparent. In addition,reducing the adhesion problem between the material has a good effect on maintainingthe stick morphology of it.In addition,we added a light heating means to reduce theadhesive material phenomena, the initial discharge capacity reached 154mAh/g bymeans of materials prepared.By using electrospinning method, I have gotten the Li₃V₂(PO₄)₃/C nanometermaterial.And by constantly adjusting,I have confirmed the basic scheme of confectingthe precursor liquid. Based on that, I did a large number of improvements. From theSEM images of sinter material,the morphology of the material did not change muchand always can't form stick morphology. I also made the coaxial compound nanometer materials of LiFe_xV_1-xPO₄ andLiFePO₄/Li₃V₂(PO₄)₃ by the electrospinning method.From their SEM results, themorphology of LiFe_xV_1-xPO₄ are mainly good sticks,Electrochemical properties of thematerial after doping has improved significantly.But the shape of coaxial compoundmaterials are irregular, which became mutually adhered granules and sticks. CV curveof the material existed both of LiFePO₄ and Li₃V₂(PO₄)₃'s redox peaks, indicating thatthe two materials have formed a complete crystal.