Effect of surface coating on the electrochemical performance of cathode made of sulfur-loaded TiO2 nanotube arrays

Abstract

Amorphous phase TiO2 nanotube (NT) arrays as sulfur reservoir are fabricated by anodization method on Ti plate used as current collector. Properties of the NT arrays before heat-treatment are evaluated with those after heat-treatment for applicability as a reservoir and conductor of sulfur electrode. A reasonably high amount of sulfur is loaded (14.8%) from 30% feed sulfur solution at 160 degrees C in the candidate NT array chosen as the sulfur reservoir. Three electrodes from the only NT array, the sulfur-loaded NT array with and without coating layer are evaluated on electrochemical performances. The sulfur electrode with coating layer, consisting of super-P and PVdF, exhibits the highest initial and retention capacity in discharge, respectively, of 1547 mAh g(-1) and 1085 mAh g(-1) up to 100 cycles. Rate capability at various C-rates from 0.1 to 30 C is also found to be exceptionally good. (c) 2017 Elsevier B.V. All rights reserved.