Sulfur/activated-conductive carbon black composites as cathode materials for lithium/sulfur battery

• Published in: Journal of power sources 2013-10, Vol.240, p.598-605
• Main Authors: Li, G.C., Hu, J.J., Li, G.R., Ye, S.H., Gao, X.P.
• Format: Article
• Language: English
• Subjects: Activated; Activation; Activation treatment; Applied sciences; Carbon black; Cathode; Cathodes; Conductive carbon black; Direct energy conversion and energy accumulation; Electric batteries; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Lithium; Lithium–sulfur battery; Materials; Scanning electron microscopy; Sulfur; Sulfur–carbon composite
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2013.02.095

The commercial conductive carbon black (CCB) with large surface area and good electrical conductivity after activation treatment is employed as conductive matrix to support sulfur for the cathode of lithium/sulfur battery. The S/activated CCB composites with 64 and 73 wt% sulfur are prepared by a simple heat treatment method. The microstructure and morphology of the as-prepared S/activated CCB composites are characterized by thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). It is demonstrated that sulfur can be loaded into the pores of the host activated CCB matrix in highly dispersed state, when sulfur loading is limited to 64 wt%. While the loaded sulfur increases to 73 wt%, some crystalline sulfur nanoparticles of less than 2 nm can be observed near the pores of the host activated CCB matrix. As expected, the S/activated CCB composite with 64 wt % sulfur presents the optimized electrochemical performance, including the utilization of active sulfur, discharge capacity and cycle stability. Apparently, in order to improve the electrochemical performance of the S/activated CCB composite, the activation treatment of the commercial CCB is essential for increasing the sulfur loading. •The commercial CCB is activated with KOH as matrix to load sulfur as cathode for Li/S battery.•After activation treatment, the surface area and pore volume of the CCB are increased.•The S/A-CCB composite with 64 wt% S presents the optimized electrochemical performance.