Chiyoda : Completed Construction to Increase the Capacity of Plant 1, Small Pilot Facilities of Solid Electrolytes, for Idemitsu Kosan Co., Ltd.

Chiyoda Global Headquarters Minato Mirai Grand Central Tower 4-6-2, Minatomirai, Nishi-ku,

Yokohama 220-8765, Japan https://www.chiyodacorp.com/en

May 14, 2025

Chiyoda Corporation (Chiyoda) and Chiyoda X-ONE Engineering Corporation (CXO), a wholly owned subsidiary of Chiyoda, are pleased to announce that they have completed capacity expansion work for Plant 1 of small pilot facilities for solid electrolytes production, for Idemitsu Kosan Co., Ltd. (Idemitsu).

Project Details:

• Client: Idemitsu Kosan Co., Ltd.

• Project Name: Capacity Expansion for Plant 1 of the Small Pilot Facilities for Solid Electrolytes Production

• Location: Ichihara City, Chiba Prefecture, Japan

Solid electrolytes are an essential material for all-solid-state batteries, considered a leading candidate for next-generation batteries. All-solid-state batteries are being developed by automobile and battery manufacturers to extend driving range, shorten charging times and improve safety in electric vehicles (EVs). Idemitsu will accelerate technical verification for establishing mass production technology by utilizing the enhanced production capacity.

The completion ceremony, held at Idemitsu's Chiba Complex on April 18th2025 and attended by Senior Managing Executive Officer Nakamoto of Idemitsu and other dignitaries, included a religious ceremony and a visit to the Plant 1. Mr Ota, President & CEO of Chiyoda, delivered a speech expressing gratitude for Idemitsu's cooperation during construction, and expectations for the potential of all-solid-state batteries.

Idemitsu will gradually scale-up the solid electrolytes manufacturing facilities, leading to commercialization. Chiyoda is also executing the Front End Engineering Design (FEED) for large pilot facilities as the next step. Chiyoda will continue to actively contribute to Idemitsu's solid electrolytes business, supporting Idemitsu improve the performance of solid electrolytes and accelerate the development of mass production technologies, thereby contributing to the widespread use and expansion of all-solid-state batteries.

As comprehensive engineering companies, Chiyoda and CXO are actively engaged in the social implementation of all-solid-state batteries towards the realization of a carbon-neutral society. Through these initiatives, Chiyoda and CXO will continue contributing to the development of a sustainable society under our purpose of 'Enriching Society through Engineering Value'.

Exterior View of Plant 1 Mr Ota: President & CEO of Chiyoda

[Reference]

Idemitsu Press Release dated April 21, 2025

https://ssl4.eir-parts.net/doc/5019/tdnet/2596572/00.pdf

For further information, please contact: Chiyoda Corporation

IR, PR & Sustainability Advanced Section Email: [email protected]

URL: https://www.chiyodacorp.com/en/contact/index.php