Preparation And Electrochemical Properties Of Natural Carbon Materials As Anode Materials In Lithium Ion Rechargeable Battery

The development of anode materials in lithium ion batteries requires highercapacity, good high rate performance, good cycle stability and lower cost. Carbonbased materials were still the major anode materials. Based on the practical problem,the electrochemical properties of TaiXi coal and microcrystalline graphite anodematerials were improved by graphitization, surface coated, doping and so on. Thescientific relationship between the modified method and electrochemical propertieswas explored.With the graphitization of TaiXi coal, modified coal as anode materials wasproposed for the first time. Carbon layer was coated on the surface of graphitizationTaiXi coal by liquid phase mixing of GC with pitch. After carbonization in1000°Ccarbon coated GC had the core shell structure, which meant the core was GC and theshell was carbon. As the anode materials in lithium ion rechargeable batteries, areversible capacity of330mAh/g and cycle efficiency of90%was obtained in firstcycle, after50cycles the reversible capacity also reached above300mAh/g.activation process also improved and a porous graphite structure was formed, higherlithium storage property was achieved due to micro-pores lithium storage mechanism.To improve the properties of microcrystalline graphite, many precursors wereinvestigated by liquid phase mixing method.In the optimum condition, a reversiblecapacity of356mAh/g and cycle efficiency of90.4%was obtained in first cycle, after25cycles the reversible capacity also reached348.1mAh/g. coated microcrystallinegraphite also showed good high rate performance and cycle stability in roomtemperature.