A robust sulfur host with dual lithium polysulfide immobilization mechanism for long cycle life and high capacity Li-S batteries

By Xiwen Wang, Chenghao Yang, Xunhui Xiong, Guilin Chen, Mingzhi Huang, Jenghan Wang, Yong Liu, Meilin Liu, Kevin Huang. Energy Storage Materials, 2019

152 citations recorded by the source corpus.

Abstract Beyond the physical lithium polysulfide (Li2Sx) entrapment of various 3D porous sulfur hosts, the importance of chemical interactions between sulfur host and Li2Sx on performance of Li-S batteries has recently been highlighted. However, most of these studies focus mainly on one type of chemical interaction and effective suppression of Li2Sx migration is still lacking. Here, we report a uniquely designed sulfur host that can immobilize Li2Sx through a dual chemisorption mechanism. The new sulfur host is consisted of an MXene matrix and polydopamine (PDA) overcoat, where Mxene forms a strong Ti–S bonding by the Lewis acid-base mechanism while PDA withholds Li2Sx through the polar-polar interaction. Benefited from the double chemisorption, the new cathode with a high sulfur loading of 5 mg cm−2 has been demonstrated with an initial capacity of 1001 mA h g−1 at a capacity retention of 65% over 1000 cycles at 0.2 C. Overall, this study not only presents a unique chemical mechanism to entrap Li2Sx, but also provides a new way to rationally design a practical sulfur cathode for high-performance Li-S batteries.

Subfields: Electrical and Electronic Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/e5f8437f210cbb58956835612d16aa21ac6af659