Negative Electrode Materials Prepared by Spherification of Natural Graphite in Different Regions
Natural flake graphite is a high quality raw material for the preparation of lithium ion battery anode materials.In this paper,the graphite concentrate with a fixed carbon content of about 95%in Jixi,Inner Mongolia and Luobei was used as raw material.The spherical shape and chemical purification were carried out in order to prepare high purity spherical graphite.The results showed that after spherification,the vibrational densities of spherical graphite in three regions were 0.96 g/cm3,0.94 g/cm3 and 0.98 g/cm3,respectively,among which Luobei graphite had the highest vibrational density and the pellet formation rate is 41.44%.The optimal purification process of mixed acid was determined:the liquid-solid ratio of mixed acid and graphite was 3 mL/g,the volume fraction of HF was 30%,the reaction time was 6 h,the reaction temperature was 70℃,and the fixed carbon content of spherical graphite in three regions were increased to 99.90%,99.88%and 99.97%,respectively.The electrochemical performance test results showed that the first charge and discharge efficiency of the graphite anode materials in the three regions was above 90%,and the first discharge capacity was higher than 360 mAh/g,which was an ideal raw material for the preparation of natural graphite anode materials.
万方数据
维普
