Next-Generation Battery Materials

As electrification advance across various fields including electric mobility, drones, and robotics in pursuit of the realization of a sustainable society, there is a growing need for advancements in battery technologies. We are advancing the development of “solid electrolytes,” a key material for “all-solid-state batteries,” which are expected to be the next generation of batteries, and building mass production technologies for them. All-solid-state batteries, which offer superior safety and durability while being environmentally friendly, are expected to be used for applications in a wide range of fields.

In the quest to achieve a carbon-neutral society, the race to develop policies and technologies that promote electrification is accelerating in countries around the world. In particular, electric vehicles (EVs) are regarded as a clean mode of transportation with a low environmental impact, but to further expand their adoption, there is a need to increase their driving range, reduce charging times, and improve safety. In addition, drones and humanoid robots are expected to play a role in addressing social challenges such as labor shortages and reducing CO2 emissions. These devices must be compact, lightweight, and high-powered, capable of operating for extended periods, and built with high safety standards. To meet these demands, significant improvements in performance through innovations in battery technologies are essential. As a result, all-solid-state batteries, which are expected to be a groundbreaking innovation in battery technology, and the evolution of solid electrolytes needed to make them a reality are attracting global attention.

In the wake of the oil crisis of the 1970s, Idemitsu began exploring the development of alternative energy sources and new materials, and has since been fully committed to research aimed at enhancing the added value of petroleum and petroleum products. Over the course of countless challenges, it was solid electrolytes that opened up new possibilities for the research we had been pursuing for many years.
Our solid electrolytes utilize “sulfur components,” byproducts of the petroleum refining process, as raw materials.
In 2001, having identified solid electrolytes as a promising solution, we shifted our R&D sights to the battery sector. Then, in 2004, we became the first in the world to achieve ionic conductivity on a par with that of an electrolyte using a sulfide-based solid electrolyte.
Our commitment to R&D that breaks free from conventional thinking, rooted in the creation of high-value-added products from components produced during the oil refining process, and our technical expertise. Thanks to the integration of these two elements, the door to the practical application and mass production of all-solid-state batteries is now beginning to open.

Building on the technical validation achieved with our two currently operational small-scale verification facilities, we will proceed to establish mass production technology through the large pilot facility, the next stage, with the ultimate goal of commercialization. We made the final investment decision regarding the large pilot facility in fiscal year 2025, with the aim of completing construction by 2027. We are also actively collaborating with materials manufacturers, automakers, and other partners to drive rapid development by leveraging each other’s expertise and technical capabilities while taking mutual needs into account.
As announced in October 2023, with the aim of commercializing all-solid-state batteries, we have begun collaborating with Toyota Motor Corporation on the development of mass production technologies for solid electrolytes and efforts to improve productivity.
With an eye toward future business expansion, we will pursue various initiatives and collaborations that go beyond partnerships with automakers, aiming to expand into a wide range of applications, such as drones and humanoid robots, where our all-solid-state batteries utilizing our solid electrolytes can truly demonstrate their full potential. As well as solid electrolytes, we will also accelerate our efforts to develop next-generation battery materials and recycling technologies for all-solid-state batteries. For example, we are collaborating with Umicore of Belgium to develop “Catholyte,” a high-performance material that integrates a solid electrolyte with a cathode material. By improving the adhesion between materials, this approach offers the potential to further enhance the performance of all-solid-state batteries. With regard to recycling, we will leverage our network to explore the creation of resource circulation systems from a long-term perspective, including potential collaborations with service stations (SS) and our power generation business.
Through these initiatives, we will contribute to the realization of a carbon-neutral, resource-recycling society.

^{*As of May 12, 2026}