(中南大学 冶金科学与工程学院， 长沙 410083)
摘 要: 研究了锂离子在天然石墨中的嵌入/脱出过程， 以及电流密度对锂离子嵌入石墨过程的影响。非现场XRD结果显示， 石墨的层间距随锂的嵌入与脱出发生先膨胀后收缩复原的变化； SEM结果显示， 小电流密度下石墨表面的SEI膜较致密、 均匀， 而大电流密度下的则疏松、不均一； 恒电流充放电测试结果显示， 在相同的嵌锂电位下锂与微晶石墨和鳞片石墨所形成的层间化合物（Li-GICs）不完全相同；合理的充放电制度有利于小幅度改善材料的大电流充放电性能。
关键字: 天然石墨； 嵌/脱锂过程；电流密度
（School of Metallurgy Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The intercalation/deintercalation of Li+ in natural graphite and the effect of current density on the intercalation of Li+ in graphite are studied. Ex-situ XRD results show that the distance between graphite layer expands and almost shrinks to it’s original state during intercalation/deintercalation of Li+ process. SEM results reveal that the SEI film of graphite is denser and uniformer in lower current density than that in higher. The Li-GICs of microcrystalline graphite is different from that of flake graphite at the same intercalation potential. Reasonable charge-discharge system is beneficial to the development of the charge-discharge performances of larger current density to a small extent.
Key words: naturalgraphite;intercalation/deintercalation of lithium ions; current density
