韩绍昌++张维华++范长岭++张翔++曾滔滔++李玲芳

摘要：在预炭化硬炭前驱体酚醛环氧树脂中掺入硼酸制备含硼原子的锂离子电池硬炭基负极材料.通过X射线衍射仪分析、扫描电子显微镜等对材料的微观结构进行表征，采用氮气吸脱附法测定材料的孔特性和比表面积，利用循环伏安、交流阻抗以及恒电流充放电实验研究材料的电化学性能.结果表明：随着硼酸掺入量的增加，硬炭的层间距、比表面积、孔体积和首次不可逆比容量变小，首次库伦效率提高，硼酸掺入质量分数为10%时，硬炭可逆比容量从332.2 mAh·g-1增长到461.1 mAh·g-1，对应的固体电解质中间相膜的电阻从33.86 Ω减少为24.53 Ω.

关键词：锂离子电池；硼酸；酚醛环氧树脂；硬炭

中图分类号：TM912.9 文献标识码：AInfluences of Boric Acid on the Structure and Electrochemical

Performance of Hard Carbon Anode

HAN Shaochang， ZHANG Weihua， FAN Changling，

ZHANG Xiang， ZENG Taotao， LI Lingfang

（College of Materials Science and Engineering， Hunan Univ， Changsha， Hunan410082， China）Abstract：Hard carbon anode containing boron atoms for lithium ion batteries was synthesized by adding boric acid in the precarbonized precursor of phenolic epocy resin. The microstructures of materials were characterized by Xray diffraction， scanning electron microscope and other technical means. The pore characteristics and specific surface areas were determined in nitrogen absorption method. The electrochemical performance of anode was analyzed by cyclic voltammetry， electrochemical impedance spectra and galvanostatic charge and discharge experiments.The results show that the layer distances， specific surface area， pore volume and initial irreversible specific capacities decrease and the initial coulombic efficiency increases with the increase of the content of boric acid. The reversible capacity increases from 332.2 mAh·g-1 to 461.1 mAh·g-1 and the corresponding resistance of solid interphase film decreases from 33.86 Ω to 24.53 Ω when the doping content of boric acid reaches 10%.

Key words：lithiumion batteries； boric acid； phenolic epoxy resins； hard carbon

锂离子电池的负极材料是储锂的主体，在充放电过程中实现了锂离子的嵌入和脱出.已经产业化的负极材料主要是各种碳材料，包括石墨化碳材料（如天然石墨、改性石墨、石墨化中间相碳微球等等）和无定形碳材料（软炭、硬炭）.相对于常用的石墨材料来说，硬炭具有长循环寿命、高倍率性能、高比容量、结构稳定、与碳酸丙烯酯（PC）电解液相容性好、低成本等优点，从而被认为是将来最具潜力的锂离子电池负极材料.然而硬炭做负极材料时存在电位平台较高或没有电位平台、首次效率低和电压滞后等缺点[1].

湖南大学学报（自然科学版）2015年第12期韩绍昌等：硼酸对硬炭基负极的结构和电化学性能的影响为了克服上……