Improving lithium-sulphur batteries through spatial control of sulphur species deposition on a hybrid electrode surface

Abstract

Lithium-sulphur batteries are attractive owing to their high theoretical energy density and reasonable kinetics. Despite the success of trapping soluble polysulphides in a matrix with high surface area, spatial control of solid-state sulphur and lithium sulphide species deposition as a critical aspect has not been demonstrated. Herein, we show a clear visual evidence that these solid species deposit preferentially onto tin-doped indium oxide instead of carbon during electrochemical charge/discharge of soluble polysuphides. To incorporate this concept of spatial control into more practical battery electrodes, we further prepare carbon nanofibers with tin-doped indium oxide nanoparticles decorating the surface as hybrid three-dimensional electrodes to maximize the number of deposition sites. With 12.5" 1/4l of 5" Li 2 S 8 as the catholyte and a rate of C/5, we can reach the theoretical limit of Li 2 S 8 capacity ∼1,470"1 (sulphur weight) under the loading of hybrid electrode only at 4.32".©2014 Macmillan Publishers Limited. All rights reserved.