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

• A multi-functional separator was developed for high-rate dischargeable Li–S battery without free liquid electrolyte.
• Li+-Nafion, PEO and super P functioned as polysulfide blocker, electrolyte absorbent, and polysulfide receiver in separator.
• Discharge capacity reached 1330 mAh g−1 at 0.2 C and 690 mAh g−1 at 10 C.
• Cell with multi-functional separator showed low capacity degradation rate of less than 0.1% per cycle.

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).

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