A Freestanding, Dissolution‐ and Diffusion‐Limiting, Flexible Sulfur Electrode Enables High Specific Capacity at High Mass Loading
Qianyi Guo, Chao Wang, Jian Ku Shang, Yu Yang, Chuan Xie, Yufeng Luo, Mingming Rong, Yi Pei, Yuan Gao, Zijian Zheng
Abstract
Abstract The acquisition of stable and high‐areal‐capacity S cathodes over 10 mA h cm −2 is a critical and indispensable step to realize the high energy density configuration. However, increasing the areal capacity of S cathodes often deteriorates the specific capacity and stability due to the aggravated dissolution of S and diffusion of solvable polysulfides in the thick electrode. Herein, the design of a freestanding composite cathode that leverages 3D covalent binding sites and chemical adsorption environment to offer dissolution‐limiting and diffusion‐blocking functions of S species is reported. By employing this architecture, the coin cell exhibits excellent cycling stability and an exceptional specific capacity of 1444.3 mA h g −1 (13 mA h cm −2 ), and the pouch cell configuration manifests a noteworthy areal capacity exceeding 11 mA h cm −2 . This performance is coupled with excellent flexibility, demonstrated through consecutive bending cycle tests, even at a sulfur loading of 9.00 mg cm −2 . This study lays the foundation for the development of flexible Li–S batteries with increased loading capacities and exceptional performance.