All-solid-state batteries (ASSBs) are considered a next-generation technology that can overcome the safety and performance limits of conventional lithium-ion batteries. Among the various types, sulfide-based ASSBs, which use sulfide-based solid electrolytes, stand out for their high ionic conductivity and excellent processability, positioning them as promising candidates for electric vehicles and energy storage systems (ESS). However, one persistent problem has hindered their commercialization: microcracks and voids that form at the electrode-electrolyte interface during charge and discharge cycles, which increase internal resistance and shorten battery lifespan.
A Korean research team has now developed a technology that dramatically improves the durability of sulfide-based all-solid-state batteries by applying an elastic ion-conductive polymer to solve this longstanding cracking problem.
The Korea Research Institute of Chemical Technology (KRICT) announced that a research team led by Dr. Dong Wook Kim, in collaboration with Professor Seong-Ju Hwang of Yonsei University and Professor Ho Seok Park of Sungkyunkwan University, developed a chemo-mechanical interfacial stabilization technology using an elastic ion-conductive polymer, published in the journal Energy Storage Materials.
An Elastic Buffer at the Interface
During the repeated charge-discharge process of sulfide-based ASSBs, the electrode materials undergo volume expansion and contraction. This repeated mechanical stress generates microcracks and interfacial voids between the electrode and the solid electrolyte, weakening the physical contact needed for ion transport and ultimately degrading battery performance over time.
To address this, the research team infiltrated an elastic ion-conductive polymer into the sulfide electrolyte layer. Unlike rigid materials, the polymer can flex and deform along with the electrode during cycling, acting as a cushioning buffer that absorbs mechanical stress and prevents crack formation at the interface, all while continuing to conduct lithium ions efficiently.
In cycling tests, cells incorporating the elastic polymer operated stably for more than 2,500 hours—a significant improvement over conventional cells. Capacity retention after 200 cycles improved dramatically, rising from just 22% in conventional cells to 75% with the new polymer, more than tripling long-term durability. The technology also reduces the need for the high external stack pressure that sulfide-based ASSBs typically require to maintain contact between layers, a practical advantage for real-world manufacturing and packaging.
Co-first authors Juhyoung Kim and Hyo Won Bae contributed to the development and characterization of the elastic polymer system alongside Dr. Kim.
“This technology presents a new paradigm for solving the interfacial degradation problem that has been one of the biggest obstacles to commercializing sulfide-based all-solid-state batteries,” said KRICT President Dr. Seokmin Shin. “We expect it to substantially accelerate the practical application of next-generation battery technologies for electric vehicles and energy storage systems.”
The research was supported by the KRICT Fundamental Research Program and the National Research Council of Science & Technology’s Global TOP Strategic Research Program.
Journal: Energy Storage Materials
DOI: 10.1016/j.ensm.2026.105169
Article Title: Chemo-mechanical interfacial stabilization using elastic ion-conductive polymers in sulfide-based all-solid-state batteries
Publication Date: 2-May-2026 (issue)
Funding: KRICT Fundamental Research Program; National Research Council of Science & Technology Global TOP Strategic Research Program (GTL24011-000)