Formation of solid electrolyte interface (SEI) and irreversible electrochemical reactions on the surface of anode during the lithiation/delithiation are considered as the main factors affecting the initial Coulombic efficiency of lithium-ion battery. In this work, different metal or/and graphene is pre-electroplated on the surface of graphite powder using a home-built electrochemical workstation, and the surface states of graphite powder are characterized using FESEM, HRTEM, and TOF-SIMS. The results show that metal or/and graphene are plated uniformly on the surface of graphite. The electrochemical property of the coin half-cell using pre-electroplated graphite as anodes shows that the metal can improve the electron/ion transfer capability of the composites that further suppress the irreversible reactions. The graphene can also control the formation of SEI on the anode, which counteract the considerable consumption of Li ions during the initial lithation/delithiation cycle.

中文翻译：

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预电镀金属或/和石墨烯对石墨阳极初始库仑效率的影响

锂化/脱锂过程中固体电解质界面（SEI）的形成和阳极表面不可逆的电化学反应被认为是影响锂离子电池初始库仑效率的主要因素。在这项工作中，使用自制的电化学工作站在石墨粉表面预电镀不同的金属或/和石墨烯，并使用 FESEM、HRTEM 和 TOF-SIMS 表征石墨粉的表面状态。结果表明金属或/和石墨烯均匀地镀覆在石墨表面。使用预电镀石墨作为阳极的纽扣半电池的电化学性能表明，金属可以提高复合材料的电子/离子转移能力，进一步抑制不可逆反应。