Japan keeps lead in solid state battery development

While lithium-ion batteries continue to improve in terms of both performance and cost, interest in solid-state batteries, which promise better energy density and safety, has not waned.

Geographically, solid state battery innovation is concentrated in a limited number of countries. According to Taipei-based intelligence provider TrendForce, China and South Korea were tailgating in commercialization behind Japan’s subsidy of over $660 million for all-solid-state batteries in 2024. 

In the 2024 Battery Industry Strategy, Japan set a target of commercializing all-solid-state batteries (ASSB) by around 2030. By the end of last year, the Ministry of Economy, Trade and Industry (METI) approved a total of four major R&D projects on ASSB materials and production, including that of Toyota, Idemitsu, Mitsui Kinzoku, and TK Works.

Japan, once the forerunner in lithium-ion battery development, now hopes to regain its market dominance in the field of next-gen battery tech. According to TrendForce, Japan once accounted for more than 90% of the global lithium-ion market share. By 2015, this figure shrank to 50% and plummeted to less than 6% today as a consequence of the rapid expansion of Chinese and South Korean counterparts.

Today, Japan possesses the most ASSB-related patents in the world and has been steadily establishing a supply chain over recent years in the hope of realizing mass production. Car makers have been leading the charge with Toyota Motors claiming more than 1,000 solid-state battery patents and readying to mass-produce solid-state batteries by 2027 or 2028. Nissan and Honda have previously revealed plans to establish solid-state battery manufacturing lines in-house.

In the meantime, China, South Korea, Europe, and the US have also been engaged in active development of this new technology leading to expectations that the global production volumes could reach GWh levels by 2027. 

Looking forward, Japanese manufacturers are likely to face a challenging task in maintaining their leading position in the ASSB market. According to TrendForce’s latest “Development Trends of Solid-State Battery Market (2025)” report, they account for 36% of the world’s ASSB patents, followed by their Chinese (27%) and South Korean (18%) counterparts.

As all-solid-state batteries move from prototype sample cells to engineering-scale production, they are expected to encounter high early-stage production costs that could raise initial product prices. TrendForce projects that, by 2030, if the scale of all-solid-state battery applications surpasses 10 GWh, cell prices will likely fall to around CNY 1/Wh ($0,14/Wh). By 2035, cell prices could decline further to CNY 0.6–0.7/Wh with rapid, large-scale market expansion.