Toyota solid-state battery materials: Idemitsu Kosan pilot facility decision

Toyota solid-state battery materials are moving a step closer to large-scale commercialization as Idemitsu Kosan Co., Ltd. has decided to introduce a large-scale pilot facility dedicated to producing key materials for next-generation electric vehicle batteries. The facility will be located at the company’s Chiba Complex in Ichihara City, Chiba Prefecture, reinforcing preparations for future EV demand.

Toyota-focused solid-state battery material production

The newly approved pilot facility will manufacture solid-state electrolytes used in all-solid-state lithium-ion batteries for electric vehicles. These materials are intended for EV models that :contentReference[oaicite:1]{index=1} plans to introduce as early as 2027, aligning material readiness with vehicle commercialization timelines.

Transition from trials to large-scale validation

At present, Idemitsu Kosan is developing mass production technologies while supplying samples from two small-scale trial facilities installed at the Chiba Complex. One of these trial units is dedicated to Toyota, while the other supports non-Toyota customers, enabling broader validation of solid-state electrolyte performance.

Demonstration results drive expansion decision

The decision to establish the large-scale pilot facility is based on demonstration results from the first Toyota-focused plant, which began operations in November 2021. These results supported confidence in scaling up production processes, leading to the formal approval of the new pilot installation.

Capacity plans and integration with upstream materials

The large-scale pilot facility is scheduled for completion in 2027 and is designed to achieve an annual production capacity of several hundred tons. This scale is intended to bridge the gap between experimental production and full commercial manufacturing of solid-state battery materials.

Lithium sulfide manufacturing underway

In parallel, Idemitsu Kosan is advancing construction of a large-scale manufacturing facility for lithium sulfide at the same Chiba Complex. Lithium sulfide serves as an intermediate raw material for solid-state electrolytes, allowing tighter integration between upstream material supply and electrolyte production.

Strategic impact on next-generation EV batteries

By combining solid-state electrolyte pilot production with lithium sulfide manufacturing at one site, the Chiba Complex is positioned as a core hub for next-generation EV battery materials. This integrated approach is expected to support stable supply, process optimization, and faster readiness for commercial all-solid-state battery deployment as automakers move toward post-2027 electrification strategies.