Improved electrochemical performance of Li-S battery via using mesoporous MnO2 nanofibers to inhibit the polysulfide diffusion

Abstract

The migration of the soluble polysulfide has become the main obstacle for the application of the Li-S battery for commercialization. Therefore, designing the suitable cathode host materials for the Li-S battery is the main research topic for the researchers worldwide. In our work, mesoporous MnO2 nanofibers are prepared and designed as the host materials for the element sulfur. The as-prepared MnO2/S composite shows much higher specific capacity and superior cycle stability during the electrochemical process. The excellent electrochemical performance is ascribed to the presence of the mesoporous MnO2 nanofibers, which could efficiently inhibit the migration of the soluble polysulfide in the electrolyte. As a result, the as-prepared MnO2/S composites exhibit initial specific capacity of 1502 mAh g−1 at 0.1 C. Besides, the specific capacity value of the MnO2/S electrode is as high as 1205 mAh g−1 after 200 cycles with only capacity retention of 89% at 0.2 C.