摘要
用abinitio/HF和DFT/B3LYP方法探究了在锂离子二次电池中锂离子在石墨负电极材料里可逆嵌脱过程 .理论计算结果表明 ,嵌锂石墨LIG (lithiumintercalatedgraphite)充放电机制是锂在石墨碳层间可逆嵌脱 ,同时伴随着锂与碳层间发生电荷连续转移和碳层堆积方式改变的协同过程 ;计算结果也明确证实 ,嵌锂石墨嵌入脱出锂离子的过程就是锂离子二次电池储存与释放能量的过程 .提出的嵌锂石墨充放电机制较好地丰富了固体电解质相界面SEI (solidelectrolyteinterphase)
Several small models of graphite, lithium intercalated graphite (LIG) and lithium have been calculated at the ab initio/HF and DFT/B3LYP levels with the 6-31G and 6-31G* basis sets to explore the charging-discharging mechanism of LIG as a negative electrode in the secondary lithium battery. The obtained results demonstrate that, whilst lithium enters and leaves the graphite lattices reversibly, the continuous charge transfer between lithium and the graphite layers synchronizes with the shift of the graphite layer stacking sequences between the AB type and the AA type. Additionally, the processes of the lithium intercalation into and deintercalation out of graphite lattices are essentially that the secondary lithium battery deposits and releases the electric energy, respectively. The above charging-discharging mechanism of LIG enriches the SEI (solid electrolyte interphase) mechanism and single electron reduction mechanism of lithium into graphite very well.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2003年第10期1582-1586,共5页
Acta Chimica Sinica
基金
吉林省自然科学基金 (No .2 0 0 2 0 6 1 8)资助项目
