SoftBank announces entry into AI batteries: Osaka Sharp LCD plant to be converted into zinc-halogen factory, partnering with South Korea's Cosmos Lab to challenge China's lithium-cobalt supply chain

SoftBank Group officially announced on May 11 that it will convert its former Sharp LCD plant in Sakai, Osaka, into a large-scale zinc-halogen battery production base. The goal is to achieve an annual production capacity of 1 GWh of energy storage systems by FY2027, making it one of the largest battery production facilities in Japan. The partnership includes South Korean zinc-halogen technology developer Cosmos Lab and DeltaX Co. By using zinc and halogen compounds to replace rare metals like lithium and cobalt, the initiative aims to fundamentally circumvent China's dominance over the global lithium and cobalt supply chain. SoftBank is considering investing tens of billions of yen by 2030 to drive capacity expansion, with the core driver being the urgency of the power gap for AI data centers. (Context: Meta announced the introduction of 1GW of "space-based solar power" and ultra-long-duration energy storage exceeding 100 hours to address the power shortage in AI data centers.) (Background: The Spring Festival Gala has become a battlefield for AI, so why is China gaining the upper hand in the US-China computing power war?) The battlefield for computing power is extending from server rooms to the underlying power grid. SoftBank Group's mobile business division stated on May 11 that it plans to launch large-scale battery cell manufacturing at the former Sharp LCD plant in Sakai, Osaka, specifically to supply energy storage for AI service infrastructure. This is not an ordinary manufacturing investment announcement, but a key move by SoftBank to fill the final gap in energy within its full-stack AI layout. The Sakai plant carries a history of Japan's manufacturing industry. Sharp once established a world-class LCD panel production line here, but it gradually declined under the competitive pressure of South Korean and Taiwanese panel manufacturers. Today, SoftBank has chosen this site as its next-generation battery production base, giving it a completely different historical significance. According to SoftBank's statement on May 11, the company will collaborate with South Korea's Cosmos Lab and DeltaX Co., aiming to start mass production from FY2027 (the Japanese fiscal year starting April 2027), with an initial annual production capacity target of 1 GWh for energy storage systems. Bloomberg reported that SoftBank is considering investing tens of billions of yen before 2030 to continuously expand production, making this facility one of the largest battery production bases in Japan. The most critical technological choice here is what sets SoftBank apart from ordinary battery manufacturers—zinc-halogen batteries, a new type of energy storage technology that uses zinc and halogen compounds as core materials, completely independent of lithium or cobalt. Electronics Weekly and Nikkei Asia reported that Cosmos Lab is the core developer of this technology. Zinc-halogen chemistry possesses cost advantages that lithium batteries struggle to match: zinc is a relatively abundant metal on Earth, the supply chain for halogen compounds is far more stable than that of lithium and cobalt, and the main deposits are not concentrated in China or within mining frameworks dominated by China. In terms of energy storage scale, an annual production capacity of 1 GWh can support the backup power needs of a medium-sized AI data center. The logic behind SoftBank's move is clear: build its own batteries, control its own supply chain, and no longer rely on external procurement. Seoul Economic Daily first revealed the background of the cooperation between Cosmos Lab and SoftBank in early May this year, characterizing the strategic nature of this partnership with the headline "SoftBank Backs Korean Startup’s Zinc Battery to Challenge China Supply Chain." This framework is not an over-interpretation by the media, but a judgment supported by specific supply chain logic. The global lithium and cobalt supply chain has long been dominated by China: China controls more than 60% of the world's cobalt refining capacity, and almost all processing of lithium battery cathode materials is completed within China. Under the geopolitical pressure of the US-China tariff war and rare earth export restrictions, Japanese and South Korean companies are actively seeking alternative paths. SoftBank's decision to bet on zinc-halogen technology and form a Japan-Korea supply chain alliance with South Korea's Cosmos Lab is equivalent to completing a de-Sinicization strategic layout at the battery material level. This trend echoes the recent rare earth game: China has implemented export controls on various critical minerals this year, and the US, Japan, and South Korea are accelerating the diversification of critical mineral supply chains. SoftBank's move comes exactly at this juncture. From a more macro perspective, this battery plant investment is an extension of SoftBank's full-stack AI layout over the past two years. SoftBank has invested in OpenAI, jointly promoted the Stargate project to deploy large-scale AI computing power in the US, holds core shares in the Arm chip architecture, and is now personally building energy storage infrastructure for AI data centers. SoftBank's logic can