South Korean battery manufacturer SK On has opened a pilot plant for solid-state batteries in Daejeon. Located at the SK On Institute of Future Technology, the facility will be used to develop sulfide-based cells and lithium metal batteries. The company aims to advance prototype development and achieve commercialization by 2029, originally planned for 2030.
Energy density of 800 watt-hours per liter
According to SK On, the approximately 4,600-square-meter pilot plant features proprietary manufacturing technology which does not require the warm isostatic pressing (WIP) process. The WIP procedure is considered complex and difficult to integrate into automated production lines. SK On claims by combining material mixing, electrode design, and optimized pressing conditions, it can achieve the same advantages as the WIP method without its limitations. The company aims to produce cells with an energy density of 800 watt-hours per liter and plans to increase this value to 1,000 watt-hours per liter in the long term.
Longer cycle life of sulfide-based SSB cells
In addition to its own development, SK On is focusing on collaborations. Since 2022, SK On has worked together with Solid Power, a US company which is active in the field of solid-state batteries. In 2025, SK On and Hanyang University reported extending the cycle life of sulfide-based solid-state cells significantly by adding a protective layer to lithium metal anodes.
