Enhanced Cyclic Stability of Sulfur Electrode by a Li-Nafion-Supported Encapsulated Configuration

Lithium-sulfur batteries are deemed to have the opportunity to replace lithium-ion batteries because of their high energy density. Nonetheless, the shuttling of soluble long-chain polysulfides severely deteriorates the cyclic performances of the batteries. Herein, an encapsulated sulfur electrode to tackle the shuttle effect is designed. This high-performance electrode is fabricated by encapsulating the active sulfur inside a sealing configuration composed of lithiated Nafion (Li-Nafion), carbon black (BP2000), and a binder of polytetrafluoroethylene. The dense surface of the encapsulated configuration can physically obstruct the mobility of soluble polysulfides. Meanwhile, the sulfonic acid groups fixed on the Li-Nafion backbone provide a robust electrostatic repulsion to inhibit the negatively charged polysulfides from migrating into the electrolyte. Therefore, the encapsulated sulfur electrode delivers 522.6 mAh g(-1) at the 600th cycle with a retention of 80.36%, exhibiting a more competitive cyclic stability than the pristine sulfur electrode.

Automated summary

The encapsulated sulfur electrode effectively addresses the shuttle effect of internal polysulfides, improving the cyclic performance of the battery.