BASF and Welion Reach Milestone on Semi-Solid-State Battery Materials

BASF and Chinese battery maker Welion cleared an important hurdle on the road to commercial semi-solid-state batteries. BASF Shanshan Battery Materials (BSBM), the German group’s joint venture in China, has shipped its first batch of cathode active materials (CAM) tailored for semi-solid cells to Welion—marking the project’s first production-scale delivery less than a year after it began in August 2024, according to Batteries News.

The new CAM uses an ultra-high-nickel formulation with a composite surface coating designed to tackle one of solid-state’s nagging technical issues: the unstable interface between the cathode and solid electrolyte. Stabilizing that boundary can raise energy density, lower internal resistance, and extend cycle life, three metrics that determine whether next-gen cells can beat today’s lithium-ion in real products.

Welion plans to integrate the material into its next generation of semi-solid-state packs targeting electric vehicles, grid-scale energy storage, and smaller platforms such as drones. Semi-solid architectures—often viewed as a bridge technology between conventional liquid-electrolyte batteries and all-solid designs—aim to deliver better safety and durability than standard Li-ion while being more practical to manufacture in the near term than fully solid-state.

“This is a milestone for our battery materials business,” said Desmond Long, CEO of BSBM. Dr. Jin Xiang, Welion’s general manager, called BASF’s materials a strong foundation for continued collaboration.

With the auto and energy sectors pushing for longer range and higher safety, truly solid-state batteries remain years from broad commercialization. But the BASF–Welion shipment suggests semi-solid technology is moving out of the lab and into supply chains, an incremental step that could accelerate the next wave of energy-storage products.