CAJ | 학술논문

制备了锂硫电池用硫-多壁碳纳米管纳米复合材料，并分别采用气相生长碳纤维(VGCFs)和导电炭黑作为复合正极的导电添加剂，通过形貌表征(SEM)、恒流充放电测试和交流阻抗分析(EIS)研究VGCFs对硫-多壁碳纳米管复合正极的影响。结果表明：采用VGCFs作添加剂的硫-多壁碳纳米管复合电极具有三维网状结构，其首次放电比容量为1254 mA·h/g，40次循环后容量保持在716 mA·h/g。与采用导电炭黑为添加剂的电极相比，采用VGCFs为添加剂的电极具有更高的活性物质利用率和更好的循环稳定性。相互搭接的纤维状VGCFs可形成稳定的导电网络，抑制正极材料及残存放电产物的团聚堆积，维持电极的多孔性，从而改善电池的电化学性能。
제비료리류전지용류-다벽탄납미관납미복합재료，병분별채용기상생장탄섬유(VGCFs)화도전탄흑작위복합정겁적도전첨가제，통과형모표정(SEM)、항류충방전측시화교류조항분석(EIS)연구VGCFs대류-다벽탄납미관복합정겁적영향。결과표명：채용VGCFs작첨가제적류-다벽탄납미관복합전겁구유삼유망상결구，기수차방전비용량위1254 mA·h/g，40차순배후용량보지재716 mA·h/g。여채용도전탄흑위첨가제적전겁상비，채용VGCFs위첨가제적전겁구유경고적활성물질이용솔화경호적순배은정성。상호탑접적섬유상VGCFs가형성은정적도전망락，억제정겁재료급잔존방전산물적단취퇴적，유지전겁적다공성，종이개선전지적전화학성능。
Vapor-grown carbon fibers (VGCFs) were introduced as conductive additives for sulfur-multiwalled carbon nanotubes (S-MWCNTs) composite cathode of lithium-sulfur batteries. The performance of S-MWCNTs composite cathodes with carbon black and VGCFs as sole conductive additives was investigated using scanning electron microscopy (SEM), galvanostatic charge-discharge tests and electrochemical impedance spectroscopy (EIS). The results show that the S-MWCNTs composite cathode with VGCFs displays a network-like morphology and exhibits higher activity and better cycle durability compared with the composite cathode with carbon black, delivering an initial discharge capacity of 1254 mA·h/g and a capacity of 716 mA·h/g after 40 cycles at 335 mA/g. The interconnected VGCFs can provide a stable conductive network, suppress the aggregation of cathode materials and residual lithium sulfide and maintain the porosity of cathode, and therefore the electrochemical performance of S-MWCNTs composite cathode is enhanced.