Kyushu Electric invests in solid-state battery maker ProLogium
Kyushu Electric Power, one of Japan's regional integrated utilities, is making a strategic investment in ProLogium, the Taiwan-based solid-state lithium ceramic battery developer, the two companies announced on 9 September. The move converts an existing industrial collaboration into formal equity participation, though neither party disclosed the investment size, the stake being acquired, or the valuation implied by the transaction.
ProLogium describes the relationship as long-standing, covering next-generation battery technology, energy applications and commercialisation opportunities. The two companies are also reported to be exploring the establishment of battery module manufacturing capacity in Japan, focusing on construction machinery and other industrial electrification uses where conventional lithium-ion chemistry faces performance constraints in demanding environments.
The deal
The absence of disclosed financial terms is notable. No investment sum, ownership percentage, or post-money valuation was released, limiting the market signal this announcement carries. What is clear is the strategic direction: ProLogium is building a network of Japanese industrial and energy partners to support commercialisation of its lithium ceramic battery technology in one of the world's most integrated advanced-manufacturing ecosystems.
ProLogium's technology centres on a solid-state battery (SSB) design that replaces the liquid electrolyte found in conventional lithium-ion cells with a ceramic material, improving thermal stability and reducing fire risk. In 2025 the company introduced what it calls a Superfluidized Inorganic Next-Generation Lithium Ceramic Battery, which it positions as combining the safety profile of a solid-state cell with manufacturability closer to conventional liquid-electrolyte cells. The company says it has delivered more than 2.4 million battery cells to date and operates the Taoke Gigafactory in Taoyuan, Taiwan, which it describes as the first commercial next-generation lithium ceramic battery gigafactory with a publicly demonstrated mass-production line. A second gigafactory in Dunkirk, France, broke ground in February 2026 and is designed to reach 4 GWh of annual production capacity by 2030, with a maximum design capacity of 44 GWh.
Market context
Solid-state batteries have attracted intense investor and industrial attention as the technology most likely to extend electric-vehicle range and improve cell safety beyond what lithium-ion can achieve. The commercialisation timeline remains contested: most analysts place cost-competitive automotive-scale SSB production in the early-to-mid 2030s at the earliest. ProLogium is among a small number of developers that can point to existing commercial volumes, though those volumes remain modest relative to automotive-scale ambitions.
Japanese utilities and industrial conglomerates have been active as strategic investors in battery technology, seeking both energy-storage optionality for their grids and supply-chain influence as industrial electrification accelerates. Construction machinery electrification, the application highlighted in this announcement, is a growing sub-market: diesel-powered excavators and heavy equipment are under increasing regulatory pressure in Europe and parts of Asia, and solid-state chemistry's resilience in temperature-extreme and high-vibration environments makes it a credible candidate for that duty cycle.
ProLogium is also progressing a planned Nasdaq listing via a business combination with Translational Development Acquisition Corp. (Nasdaq: TDAC), with a registration statement filed with the US Securities and Exchange Commission. Completion remains subject to shareholder and regulatory approvals. A successful listing would give the company access to US public capital markets ahead of its Dunkirk gigafactory ramp.
Investors tracking the solid-state battery space will want to see ProLogium disclose the terms of the Kyushu Electric investment, a named offtake volume for its French facility, and progress on the TDAC business combination as the near-term milestones that will clarify the company's commercial trajectory.