(中南大學(xué) 冶金科學(xué)與工程學(xué)院， 長沙 410083)
摘 要: 研究了鋰離子在天然石墨中的嵌入/脫出過程， 以及電流密度對鋰離子嵌入石墨過程的影響。非現(xiàn)場XRD結(jié)果顯示， 石墨的層間距隨鋰的嵌入與脫出發(fā)生先膨脹后收縮復(fù)原的變化； SEM結(jié)果顯示， 小電流密度下石墨表面的SEI膜較致密、 均勻， 而大電流密度下的則疏松、不均一； 恒電流充放電測試結(jié)果顯示， 在相同的嵌鋰電位下鋰與微晶石墨和鱗片石墨所形成的層間化合物（Li-GICs）不完全相同；合理的充放電制度有利于小幅度改善材料的大電流充放電性能。
關(guān)鍵字: 天然石墨； 嵌/脫鋰過程；電流密度
LI Jie, HU Guo-rong
（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
