High Stable Sulfur Cathode with Self-Healable and Physical Confining Polydimethylsiloxane Interlayer

Li-sulfur (Li−S) batteries are promising high-performance power sources, but their practical application is significantly impeded by the large volume change and diffusion of polysulfides (i. e., shuttle effect). Here we report that such issues can be effectively addressed by rationally designing a self-healable and confining interfacial nanolayer. The goal is achieved by encapsulating individual sulfur microparticles with a polydimethylsiloxane (PDMS) nanoshell cross-linked by dynamic imine bonding. The nanoshell well adapts the volume change, timely remediates itself after breaking, but also in situ confines the generated polysulfides, which ensures a “robust micro-interface” between each sulfur particle and the electrolyte in the cycling process. Consequently, the resulting sulfur cathodes exhibit excellent energy-storage performances even at a high sulfur loading. We believed that this design of a multifunctional micro-interfacial layer provides an alternative insight into the intrinsic problems of sulfur cathodes.