High capacity and cycle stability Rechargeable Lithium-Sulfur batteries by sandwiched gel polymer electrolyte

A novel sandwiched gel polymer electrolyte (GPE) was prepared using a facile method as separator solely for rechargeable Lithium-Sulfur batteries. As a result of the strong physical shielding and chemical absorption of GPE, the separator can not only suppress shuttle effect in ether-based electrolyte, but also improve utilization of sulfur significantly resulting in a high capacity. The PVDF layers could absorb ether-based electrolyte largely and then enhance Li+ transfer; the PMMA layer can be utilized to trap the dissolved polysulfides. Lithium-Sulfur batteries with the sandwiched GPE separator shows an encouraging electrochemical performance. A high initial discharge capacity of 1711.8 mAh g−1 is obtained, and the capacity retains at 1145.3 mAh g−1 after 50 cycles at 200 mA g−1, which is higher than that of the cell with the commercial separator. These results indicate that the appropriate GPE separator is more suitable in Lithium−Sulfur batteries applications.