Three-dimensional twisted fiber composite as high-loading cathode support for lithium sulfur batteries

Abstract

3D electrodes are widely researched for high sulfur loading, but still face challenges toward practical applications due to complex design, limited long cycling stability, and high volumetric changes. Herein, we report an efficient, facile, and cost-effective carbon-tungsten disulfide twisted cloth fibers (C/WS2-TCF/S) as a 3D cathode for Li–S battery. The C/WS2-TCF/S cathode combines the advantages of evenly-dispersed C/WS2 matrices and interconnected twisted cloth fiber networks which trap the polysulfide species, accommodate large active sulfur, and maintain the stable cycling performance even cycled at higher sulfur loading. In situ Raman spectroscopy further reveals the low shuttling effect observed with C/WS2-TCF/S cathode. With sulfur loadings of 2 mg cm−2, 3.5 mg cm−2, and 5 mg cm−2, C/WS2-TCF/S cathode shows high specific capacities at 1C. Moreover, for a sulfur loading of 4.5 mg cm−2, an initial discharge capacity of 722 mA h g−1 is delivered with capacity decay of 0.06% per cycle over 500 cycles at 0.5C. This work is valuable for the efficient design and preparation of high-loading cathode of lithium-sulfur batteries.