A Natural Polymer Captor for Immobilizing Polysulfide/Polyselenide in Working Li–SeS2 Batteries

Nano-Micro Letters

Lingzhi Huang¹  Hao Wu¹  Yunhong Wei¹  Yi Guo¹  Boya Wang¹  Peng Jing¹  Yin Zhang¹  Yun Zhang¹  Qian Wang¹  Yueying Zhang¹  Jingyu Sun²  Menglei Wang² 

[1] Engineering Research Center of Alternative Energy Materials and Devices of Ministry of Education, College of Materials Science and Engineering, Sichuan University;Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, College of Energy, Soochow Institute for Energy and Materials Innovations (SIEMIS), Soochow University;

关键词: Li–SeS2 batteries;    Nicandra physaloides pectin;    Interlayer;    Shuttle effect;    Pouch cells;   

DOI  :  10.1007/s40820-021-00629-z

来源: DOAJ

【 摘 要 】

Abstract SeS2 has become a promising cathode material owing to its enhanced electrical conductivity over sulfur and higher theoretical specific capacity than selenium; however, the working Li–SeS2 batteries have to face the practical challenges from the severe shuttling of soluble dual intermediates of polysulfide and polyselenide, especially in high-SeS2-loading cathodes. Herein, a natural organic polymer, Nicandra physaloides pectin (NPP), is proposed to serve as an effective polysulfide/polyselenide captor to address the shuttling issues. Informed by theoretical calculations, NPP is competent to provide a Lewis base-based strong binding interaction with polysulfides/polyselenides via forming lithium bonds, and it can be homogeneously deposited onto a three-dimensional double-carbon conductive scaffold to finally constitute a polysulfide/polyselenide-immobilizing interlayer. Operando spectroscopy analysis validates the enhanced polysulfide/polyselenide trapping and high conversion efficiency on the constructed interlayer, hence bestowing the Li–SeS2 cells with ultrahigh rate capability (448 mAh g−1 at 10 A g−1), durable cycling lifespan (≈ 0.037% capacity attenuation rate per cycle), and high areal capacity (> 6.5 mAh cm−2) at high SeS2 loading of 15.4 mg cm−2. Importantly, pouch cells assembled with this interlayer exhibit excellent flexibility, decent rate capability with relatively low electrolyte-to-capacity ratio, and stable cycling life even under a low electrolyte condition, promising a low-cost, viable design protocol toward practical Li–SeS2 batteries.

【 授权许可】

Unknown