石墨
锂(药物)
材料科学
阳极
电导率
Crystal(编程语言)
离子
堆积
化学工程
分析化学(期刊)
化学
复合材料
物理化学
有机化学
电极
工程类
内分泌学
医学
程序设计语言
计算机科学
作者
Zhiwei Liu,Yang Shi,Qinghe Yang,Haiping Shen,Fan Qiming,Hong Nie
出处
期刊:RSC Advances
[The Royal Society of Chemistry]
日期:2023-01-01
卷期号:13 (43): 29923-29930
被引量:1
摘要
Graphite is nowadays commonly used as the main component of anode materials of lithium-ion batteries (LIBs). It is essential to deeply investigate the fundamentals of artificial graphite to obtain excellent anode, especially crystal structure and electronic properties. In this report, a series of graphite with different crystal structure were synthesized and used for anodes of LIBs. Meanwhile, a concise method is designed to evaluate qualitatively the conductivity of lithium ion (σLi) and a profound mechanism of lithium storage was revealed in terms of solid state theory. The conductivity analysis demonstrates that the graphite with longer crystal plane and lower stacking layers possesses higher conductivity of electron (σe). On the other hand, lower initial charge/discharge voltage indicates the graphite with lower La and higher Lc holds higher conductivity of lithium ion (σLi). According to the solid state theory, graphite is considered to be a semi-conductor with zero activation energy, while the lithium intercalated graphite is like a conductor. The conductivity of graphite mainly depends on the σe, while the conductivity of lithium intercalated graphite can be determined by the summation of σe and σLi. In lower charge/discharge rate, Li+ have enough time to insert into the graphitic layer, making the special capacity of graphite primarily determined by σe. However, with the increase of charge/discharge rate, Li+ insertion/extraction will become more difficult, making σLi become the mainly factor of the graphite special capacity. Therefore, the graphite with longer crystal plane and lower stacking layers owns higher specific capacity under slow charge/discharge rate, the graphite with shorter crystal plane and higher stacking layers shows relatively lower specific capacity under rapid charge/discharge rate. These results provide important insights into the design and improvement of graphite's electrochemical performance.
科研通智能强力驱动
Strongly Powered by AbleSci AI