SoftBank will manufacture zinc-halogen batteries at its Sakai, Osaka facility, targeting gigawatt-hour-scale production by March 2028. The water-based electrolyte technology eliminates thermal runaway risk, a critical advantage for co-located energy storage inside AI data centers.
Key facts
- Gigawatt-hour-scale production target by March 2028
- ¥100 billion ($637 million) annual revenue goal by fiscal 2030
- Sakai site: 440,000 sq meters, 150+ MW data center
- DeltaX's Cell to Pack: 5.37 MWh per 20-foot container
- SoftBank's $4B DigitalBridge acquisition for data center capacity
SoftBank is extending its AI infrastructure vertical integration into energy storage. The company will produce zinc-halogen batteries using water-based electrolytes at the former Sharp LCD panel factory in Sakai, Osaka — the same 440,000-square-meter site being converted into a 150+ megawatt AI data center [According to Tom's Hardware].
Why this matters more than the press release suggests: SoftBank is not just buying batteries; it is manufacturing them, co-located with compute and solar panel production on a single campus it calls the "GX Factory" (energy) and "AX Factory" (AI). That integration lets SoftBank sidestep lithium-ion supply chain bottlenecks and thermal risks that have forced other operators to build separate battery buildings.
The zinc-halogen cells, developed by South Korean startup Cosmos Lab and integrated by DeltaX, use pure water as electrolyte — eliminating the flammable organic solvents in lithium-ion cells. DeltaX's Cell to Pack technology achieves 5.37 MWh in a standard 20-foot container [per the source]. SoftBank expects the battery unit to generate more than ¥100 billion ($637 million) in annual revenue by fiscal 2030.
The vertical integration pattern
The battery play follows SoftBank's $4 billion acquisition of DigitalBridge for data center development capacity, its control of Arm (whose architecture underpins most AI accelerators), and its planned 10-gigawatt Ohio data center complex requiring a $33 billion natural gas power plant. Last month, SoftBank announced a robotics unit to automate data center construction [as previously reported].
While zinc-based batteries have shorter lifespans than lithium-ion equivalents, Cosmos Lab is working to address dendrite buildup on electrodes. The trade-off may be acceptable for AI operators who prioritize safety and supply chain independence over cycle life.
What to watch
Watch for the fiscal 2028 production milestone and whether Cosmos Lab resolves dendrite buildup to extend cycle life. Also track SoftBank's Ohio data center power plant plans — if that project lands battery storage, it signals scaled deployment.
