Toyota & Idemitsu announce solid-state battery development cooperation

Toyota is joining forces with the Japanese energy company Idemitsu Kosan to advance the development and production of solid-state batteries for its future electric cars. The collaboration focuses on sulphide solid electrolytes, which are evaluated as a promising material for achieving high capacity and performance for BEVs.

Toyota and Idemitsu Kosan’s cooperation is expected to take place in three phases, ranging from the development of sulphide solid electrolytes to their production in a pilot plant and large-scale production. Toyota is reportedly targeting commercialisation of solid-state batteries between 2027 and 2028. Idemitsu Kosan had also agreed to cooperate with Umicore to develop high-performance materials for solid-state batteries last year.

The collaboration is to be split into three phases – starting with the “Development of sulfide solid electrolytes and preparation for a large pilot facility” in the first, phase, this will be followed by mass production at a pilot facility, and finally rounded out with the “Study of future full-scale mass production”

Idemitsu has some previous experience in the field and states that it has been “developing production technologies of lithium sulfide which is an intermediate material for solid electrolytes, using by-products which are generated in the course of petroleum refining”. Additionally, Idemitsu has been attempting to reach mass production with technology on sulfide solid electrolytes, aiming to establish a stable supply system.

“Idemitsu Kosan and Toyota Motor Corporation have agreed to collaborate on the mass production of solid-state batteries. Specifically, our two companies will combine their separate efforts to mass-produce new materials and establish a supply chain for solid electrolytes, which hold the key to the commercialization of solid-state batteries,” said Koji Sato, President and CEO of Toyota, adding: “First, between 2027 and 2028, we will start to produce solid-state batteries for use in battery electric vehicles. We will then lay the foundation for mass production.”

toyota.com, idemitsu.com (PDF)