High-performance nitrogen-doped titania nanowire decorated carbon cloth electrode for lithium-polysulfide batteries

Abstract

A semi-liquid polysulfide cathode renders a higher sulfur loading for Li-S batteries. However, the aggravated polysulfide shuttle effect and the poor interaction between polysulfide and carbonaceous electrode lower the battery’s cycling stability and performance. Here we report a freestanding N-TiO2 nanowire (NW) decorated carbon cloth electrode for a Li-polysulfide battery, where the nitrogen doping in the formed nanowires allows for a higher electrical conductivity and stronger polysulfide binding ability. Meanwhile, with the facile adsorption of S42− and more active sites provided by the nanowire structure, Li2S precipitation can be improved as well. With the rationally engineered nanostructured polysulfide binding electrode, the battery achieves a remarkably enhanced cycling stability and prolonged discharge capacity (1210mAhg−1, 0.2C and 600mAhg−1, 1C), in comparison with the pristine carbon cloth (890mAhg−1, 0.2C and 210mAhg−1, 1C). The facile strategy of fabricating conductive and polysulfide binding nanostructure in this work is thus expected to facilitate the design of high-energy sulfur cathode.