Accelerated Reversible Conversion of Li<sub>2</sub>S<sub>2</sub> to Li<sub>2</sub>S by Spidroin Regulated Li<sup>+</sup> Flux for High‐performance Li‐Sulfur Batteries
Mingliang Liu, Zhen Wu, Shujun Liu, Tong Guo, Peng Chen, Xuan Cao, Shencheng Pan, Tianhong Zhou, Lea Pompizii, Murad Najafov, Ali Coşkun, Yongsheng Fu
Abstract
Abstract Regulating the transformation of sulfur species is the key to improving the electrochemical performance of lithium‐sulfur (Li−S) batteries, in particular, to accelerate the reversible conversion between solid phase Li 2 S 2 and Li 2 S. Herein, we introduced Spidroin, which is a main protein in spider silk, as a dual functional separator coating in Li−S batteries to effectively adsorb polysulfides via the sequence of amino acids in its primary structure and regulate Li + flux through the β‐sheet of its secondary structure, thus accelerating the reversible transformation between Li 2 S 2 and Li 2 S. Spidroin‐based Li−S cells exhibited an exceptional electrochemical performance with a high specific capacity of 744.1 mAh g −1 at 5 C and a high areal capacity of 7.5 mAh cm −2 at a low electrolyte‐to‐sulfur (E/S) ratio of 6 μL mg s −1 and a sulfur loading of 8.6 mg s cm −2 .