Toyota and Idemitsu Kosan Collaborate for Mass Production of All-Solid-State Batteries

In related news, Toyota Motor Corporation and Idemitsu Kosan Petroleum Corporation of Japan have announced their collaboration in the mass production of all-solid-state batteries for pure electric vehicles. Their partnership aims to focus on the research and development of solid-state electrolyte mass production technology and productivity enhancement. The goal is to achieve practical implementation of all-solid-state batteries by 2028, with the batteries entering the market from 2027 onwards. The jointly-issued communiqué states that the all-solid-state batteries resulting from this collaboration utilize sulfide solid electrolyte, enabling high capacity and power output. The intermediate material used in sulfide solid electrolytes, lithium sulfide, is derived from sulfur-containing by-products of petroleum refining.

The collaboration between Toyota and Idemitsu Kosan will proceed in three phases.

Phase 1

The collaboration between Toyota and Idemitsu Kosan begins with the research and development of sulfide solid electrolytes, along with the necessary preparations for mass production verification.

Phase 2

In this phase, Idemitsu Kosan takes the lead in manufacturing and mass-producing sulfide solid electrolytes. Meanwhile, Toyota focuses on conducting research and development for all-solid-state batteries that utilize this electrolyte. Additionally, Toyota works on the production of pure electric vehicles equipped with these advanced batteries. The objective is to introduce these vehicles to the market sometime between 2027 and 2028.

Phase 2

Once the second phase concludes, the companies will evaluate the outcomes and make decisions regarding future plans for mass production. This phase serves as the final stage of the collaboration, where the companies will determine the next steps based on the results achieved in the previous phases.

During a press conference, Toyota Motor Corporation President Tsuneharu Sato emphasized the advantages of all-solid-state batteries, including their short charging time, long range, high output power, resistance to high temperatures and high voltages, and excellent safety features. These batteries can meet the power performance demands of various vehicles, including high-performance sports cars and business vehicles that require frequent fast charging.

In July 2023, a research team led by Distinguished Professor Ryoji Suganno of the Tokyo Institute of Technology in Japan made notable progress in fast charging performance and capacity of all-solid-state batteries. This achievement was made through the development of new basic materials and a re-evaluation of manufacturing processes. The team's research, published in the American journal "Science," utilized high-entropy materials to design a solid electrolyte with enhanced ion conductivity. By increasing the composition complexity of known lithium fast ion conductors, the lithium ion conductivity was improved by approximately 2.3-2.3% compared to traditional materials, resulting in significantly shorter charging times. This represents a potential 3.8-fold improvement in battery charging performance compared to current traditional batteries, making it the highest level achieved globally thus far.

Currently, solid-state batteries are still in the research and development stage worldwide. They face several technical challenges, such as the need to eliminate electrolytes that hinder ionic conductivity and affect charging performance, as well as the improvement of contact between solid electrolytes, which can lead to reduced internal resistance.