South Korean battery manufacturer SK On has released new research results on solid-state batteries. The company is currently working on two different types of solid-state batteries, one based on polymer oxide and the other on sulfide. In research projects with universities, progress has been made in improving cycle life. According to the company, the batteriesʼ market launch is planned for 2028 and 2030, respectively.
Three times more cycles than before
Together with Hanyang University, a process for stabilizing the anode-electrolyte interface in sulfide-based all-solid-state lithium metal batteries was investigated. The goal was to reduce the cyclic capacity loss that has limited the battery chemistryʼs technical use. The researchers removed interfering passive layers from the anode surface by immersing it in a chemical solution. This created a protective layer with increased ionic conductivity and mechanical stability. According to SK On, this enabled more than 300 charge-discharge cycles at room temperature – about three times as many as previously achieved with similar cells.
Further development of polymer-based SSBs
Another research topic was the thermal curing of gel polymer electrolytes. In collaboration with Yonsei University, it was shown that a longer cure time can slow down the cathodeʼs degradation. Batteries cured for 60 minutes showed significantly less loss of discharge capacity than batteries cured for a shorter time. The team used quantum mechanical calculations to clarify the degradation mechanisms. They identified correlations between residual monomers, side reactions, and the formation of damaging interfaces. According to SK On, the results will contribute to the further development of polymer-based solid-state batteries (SSBs).
