A novel laminated separator with multi functions for high-rate dischargeable lithium-sulfur batteries

摘要

A novel high-rate dischargeable semi-solid Li-S battery without free liquid electrolyte is assembled using a multi-functional separator with a polysulfide shield. The polysulfide shield is composed of Li+-Nafion, polyethylene oxide, and super P carbon. Hierarchical porous carbon is used as a sulfur holder to anchor polysulfide and improve cathode conductivity. Unlike all-solid Li-S batteries, the resultant Li-S battery shows excellent performance in both rate capacity and cycleability. The sulfur lithiation capacity reaches 1330 mAh g(-1) at 0.2 C (0.335 A g(-1) of S) and 690 mAh g(-1) (338 mAh g(-1) of electrode materials) at 10 C (16.75 A g(-1) of S). The cell with the fabricated separator (SNP/Celgard) showed very low capacity degradation rate of less than 0.1% per cycle at 1 C (a discharge current density of 1.675 A g(-1)). (C) 2015 Elsevier B.V. All rights reserved.