Research Of Graphitized Needle Coke Coated By Phenolic Resin Pyrolytic Carbon As Anode Material For Lithium Ion Battery

Graphitized needle coke was used as anode material for lithium ion battery (LIB) in this paper. The LIB anode material with outstanding performance in capacity, efficiency and cycle abilities was prepared by phenolic resin coating, surface oxidation and oxidation-coating. The influence of the amount of resin, carbonization temperature and surface oxidation-coating on the composites' microcrystalline structure and electrical performances were studied.The composite needle coke was prepared by solidifying phenolic resin on the surface. Then the influence of the amount of resin and carbonization temperature was discussed, and it turned out that the the first charge and discharge efficiency of the composite increased and then decreased along with the increasing amount of resin and temperature of carbonization. The results indicated that the composites'performance was best when it had 20% phenolic resin and then carbonized under 800℃, the first charge capacity and charge-discharge efficiency were 328.19mAh/g and 87.85%, the charge capacity after 50 cycles still remains 309.59 mAh/g, and the capacity retention rate was 83.06%.After surface oxidized by H2O2 and coated by phenolic resin, this new composites' crystal structure and electrical performance was studied. It is found that surface oxidation can change the type of functional groups of the material and improve the compatibility of needle coke with the electrolyte. The results showed that the composite which coated 20% phenolic resin after surface oxidized by 30% H2O2 exhibited good electrochemical performance, the first charge capacity and charge-discharge efficiency were 358.26mAh/g and 90.56%, the charge capacity after 50 cycles still remains 340.66mAh/g, and the capacity retention rate was 86.04%. These researches were important to develop anode materials for lithium ion battery with low-cost and good electrochemical performance.