Abstract: Activated graphene nanoplates(a-GNPs)were prepared by using the hydrothermal method with the activating agent of ZnCl₂,and the influences of different process parameters on the pore structure of a-GNPs were also investigated. Si nanoparticles coated with the conductive polyaniline(PANI) were mixed with suitable amounts of a-GNPs. After the subsequent pyrolysis,the Si/p-PANI/a-GNPs composites were obtained,which could be used as the negative electrode material of Li-ion batteries. The pore structure of a-GNPs was characterized by TEM,the variation of covalent bonds of PANI before and after pyrolysis was analyzed by FTIR,and the structure and morphology of the Si/p-PANI/a-GNPs electrode were observed by SEM. The electrochemical performance of as-prepared Si/C composite electrode was tested by electrochemical methods such as cyclic voltammetry,electrochemical impedance spectrum and galvanostatic charge-discharge. The results indicated that the lithium storage capacity and stability of Si/p-PANI/a-GNPs electrode were significantly improved compared with that of pure Si and Si/p-PANI electrodes. The reversible specific capacity of the Si/p-PANI/a-GNPs electrode prepared at optimized conditions reached 1093.4mA·h/g after 50 charge/discharge cycles,which increased by 415.3% and 112% compared to that of Si electrode and Si/p-PANI electrode,respectively. This was primarily due to the contribution of a-GNPs to the improvements in electrolyte transmission and conductivity.

Key words: electrochemistry, Si/C composites, nanomaterial, activated graphene, stability

摘要： 采用水热法以ZnCl₂为活化剂制备活化石墨烯纳米片（a-GNPs），并研究了工艺参数对其孔结构的影响。将表面包覆导电聚苯胺（PANI）的硅纳米粒子与a-GNPs以一定比例混合，经热解形成Si/p-PANI/a-GNPs复合材料用于锂离子电池负极。采用TEM对a-GNPs孔结构进行了表征；采用FTIR分析了PANI热解前后化学键的变化；采用SEM分析了电极结构和形貌；采用循环伏安、交流阻抗和恒流充放电等方法测量了硅复合电极的电化学性能。实验结果表明，Si/p-PANI/a-GNPs复合电极的储锂容量和稳定性有明显改善，400mA/g恒电流充放电循环50次后可逆比容量达到1093.4mA·h/g，比Si电极和Si/p-PANI电极分别提高了415.3%和112%。这主要归因于a-GNPs对电解质传输的促进作用以及电导的贡献。

关键词: 电化学, 硅碳复合材料, 纳米材料, 活化石墨烯, 稳定性