Korean Team Develops Stretchable Ion-Conductive Polymer Layer to Extend Sulfide Solid-State Battery Lifespan

A research team led by Dr. Dong Wook Kim at the Korea Research Institute of Chemical Technology, in collaboration with Professor Seong-Ju Hwang’s group at Yonsei University and Professor Ho Seok Park’s team at Sungkyunkwan University, has developed a technology that integrates an elastic ion-conducting polymer into sulfide-based all-solid-state batteries. By incorporating an elastic layer into the battery structure, this approach mitigates internal stresses caused by electrode volume changes during charge–discharge cycles, thereby reducing crack formation and interfacial degradation and significantly enhancing the battery’s cycling durability. The findings have been published in the journal *Energy Storage Materials*. Sulfide-based solid electrolytes are considered ideal candidates for all-solid-state batteries due to their high ionic conductivity, making them suitable for fast-charging and high-power applications. However, their inherent rigidity leads to crack formation upon repeated cycling when in direct contact with electrodes, as accumulated mechanical stress impedes both ion and electron transport, resulting in rapid capacity fade. The newly introduced elastic polymer layer effectively suppresses these issues, substantially extending battery lifespan.