Study Of The Preparation And Modification Of Lithium Ion Battery Graphite Anode Material

Lithium ion batteries with large discharge capacity,high energy density,good cycle discharge performance,low cost and so on,which has become the most used secondary batteries.In recent years,the research on battery materials has become the focus of research,especially the composite materials are widely studied.It is precisely because of this composite electrode material has a better electrochemical performance,which has a great effect on the electrochemical performance of the battery.Therefore,this paper mainly studies the different electrochemical properties of composite materials,by changing the experimental conditions in order to improve the comprehensive performance of anode materials,and using X-ray diffraction(XRD),scanning electron microscopy(SEM),electrochemical workstation and a series of test equipment to characterize and analyze the materials,get the best experimental technique.In this experiment,the materials were oxidized by concentrated sulfuric acid,the crystal structure of graphite oxide was improved by coating with phenolic resin,and the negative electrode material with good performance was obtained.Study on the coating amount,calcination temperature and calcination time of materials,the final test results showed that: With the calcination time of 7 h,calcination temperature of 750℃ for the premise,the amount of coating phenolic resin was 9% when compared to other materials coated and single graphite oxide type electrode material has more excellent electrochemical performance.At 0.1 C ratio,the initial discharge specific capacity of the material was 953 mAh/g when the coating amount was 9%,the initial discharge specific capacity of the material was 784 mAh/g when the coating amount was 3%,the initial discharge specific capacity of the material was 849 m Ah/g when the coating amount was 15%,compared with the theoretical discharge capacity than graphite oxide electrode materials 372 mAh/g has a larger increase,under the optimal conditions,the capacity retention rate of the material after 20 cycles is still more than 98%,and the electrochemical impedance of the material was the best,has a good effect to improve the comprehensive electrochemical performance of electrode materials.Preparation of titanium and graphite oxide composite anode material,and through a series of characterization tests,results show that under the conditions of the doping amount of titanium based materials 10% calcination temperature 600℃calcination time7 h,material surface morphology is good,no reunion phenomenon.The first discharge capacity of the material was 917 mAh/g,the doping amount under the same conditions with respect to 500℃ and 700℃ respectively increased 117 mAh/g and 102 mAh/g,the overall circulation of materials of terrain were increased by 1.92% and 5.83%,material in the 20 cycle of the discharge process showed a good cycle characteristics,cycle efficiency is always maintained at 98%~100%,discharging smoothly.Preparation of silicon-graphite oxide composite materials by doping silicon materials,electrochemical composite anode materials on the performance of doping amount,calcination temperature,different rate,test analysis showed that under the conditions of the doping amount of silicon based materials 15% calcination temperature650℃ calcination time 7 h,the crystal structure of the material was completely,the expansion was full,the apparent appearance of the material was smooth,there was no small particles or aggregation phenomenon.The first discharge specific capacity of the composite was 803 mAh/g at 0.1 C ratio,the irreversible specific capacity was 48 m Ah/g,and the cycle efficiency was 94.02%.With the increase of the ratio of 0.1 C,0.2C,0.5 C,1 C,the first charge and discharge performance of the material has declined,respectively 803 mAh/g,715 m Ah/g,677 mAh/g,559 mAh/g.The cycle efficiency of the 20 cycles was 96.5%,89%,87%,96%,respectively.