纯化前后天然石墨的电化学嵌/脱锂性能

Electrochemical Intercalation/deintercalation Li Performancesof Natural Graphite before and after Purification

研究了天然石墨的纯化工艺和纯化前后天然石墨的电化学嵌/脱锂性能。研究结果表明,采用酸浸与加碱烧结相结合纯化工艺可以得到含碳量达99%的纯化石墨,且采用该工艺没有改变石墨的微观结构;与未纯化的石墨相比,纯化石墨的第1次循环效率明显提高,第1次不可逆容量较大幅度降低;纯化前、后的微晶石墨嵌/脱锂电化学性能均比鳞片石墨的嵌/脱锂电化学性能差,这主要是由于2种石墨存在结构差异。

Purification technology and electrochemical intercalation/deintercalation Li^+ (IDL) performances of natural graphite (NG) were studied. The experimental results show that NG containing 99% carbon can be obtained by the purification technology, by combining acid soaking and alkali sintering, and the technology doesn't change micro-structure of NG. Compared with original NG, the IDL performances of purified NG is improved greatly, especially, its 1st cycling efficiency obviously is increased, and its 1st cycling irreversible capacity is depressed much more. The IDL performances of micro-crystalline graphite are inferior to those of natural flake graphite mainly due to the difference between their structures.