石墨负极充放电过程的DFT研究  

Theoretical Studies on the Charge and Discharge Processes of Graphite Cathode with DFT Method

作　　者：黄宗浩[1] 阚玉和[1] 徐栋[1] 马淑荣[1] 杨桂霞[1] 孟素慈[1] 苏忠民[1] 

机构地区：[1]东北师范大学化学学院,长春130024

出　　处：《高等学校化学学报》2005年第12期2289-2292,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:20474008)资助

摘　　要：用量子化学DFT-B3LYP/6-31G(d)方法计算了锂沿石墨层堆积的Z ig-zag和Arm-chair方向嵌脱及在石墨表面附着和脱附的过程.结果表明,锂嵌入过程是体系能量升高的储能过程,势垒最高点是锂在碳原子正投影位置,即在C—C键投影位置,而在苯环中心投影位置最低,为嵌锂的最佳位置,锂嵌脱的最佳途径应为arm-chair方向;锂在石墨表面附着也是储能过程,苯环中心上方是石墨表面近距离附着机率最高的位置.The intercalation and absorption processes of Li in graphite cathode of Li-secondary battery were discussed by DFF-B3LYP/6-31G（d） method of quantum chemistry. The storage energy curves of the intercalation processes through the routes of arm-chair and zig-zag directions and the adsorption processes of Li on the graphite surface along three typical directions were calculated. The results show that （ 1 ） the intercalation process of Li is a process of energy storage ; when Li is just located on the projecting position of carbon atom, the system energy is the highest; when Li is located on the projecting position of carbon-carbon bond, the system energy is higher, and when the Li located on the projecting position of benzene ring center, the system possesses the lowest energy and is the most stable. The arm-chair direction is the most probable route for intercalating of Li to graphite cathode ; （2） the process of adsorption of Li on the graphite cathode surface is a process of energy storage, too ; the position over the center of benzene ring is the most probable adsorption position when Li is close to the graphite surface. The present article provides a very useful image for understanding and improving the charge and discharge properties of the graphite cathode.

关 键 词：锂离子二次电池 石墨 充放电过程 密度泛函理论 

分 类 号：O641[理学—物理化学]