ZnO nanoparticles filled tetrapod-shaped carbon shell for lithium-sulfur batteries

Employ of hollow nanostructure carbon materials as a host framework for sulfur cathode is a promising strategy to cope with the notorious posers in lithium-sulfur (Li-S) battery. However, the dissolution and diffusion of intermediate polysulfides in electrolytes still result in rapid capacity loss and poor rate performances, due to the weak interaction between polarized lithium polysulfides and non-polarized carbon host. To address this challenge, a bipolar material, zinc oxide embedded tetrapod-shaped carbon shell (TCS/ZnO) is designed for polysulfides immobilization in Li-S battery. The TCS/ZnO composites are synthesized through a CVD process using tetrapod shaped ZnO nanowhiskers as template, following by a partially hydrogen etching treatment. Attributed to the strong chemisorption of ZnO to polysulfides, high initial specific capacity of 1284 mAh g(sulfur)(-l), stable Coulombic efficiency of similar to 99.5% and excellent cycling stability (815 mAh g(sulfur)(-l) after 100 cycles at 0.2 C) are exhibited for S-TCS/ZnO cathode with optimized ratio of ZnO. (C) 2018 Elsevier Ltd. All rights reserved.