# East Asia Brief — Batteries & Electric Vehicles: Japan

Cell capacity, cathode and anode materials, EV production and the trade rules that decide where they ship.

- [Japanese automakers standardize prismatic battery cold tests as EV timelines advance](https://eastasiabrief.com/batteries-ev/japanese-automakers-standardize-prismatic-battery-cold-tests-ev-timeline-75) — Shared public labs and automaker test benches expand sub-zero cell protocols to resolve winter range loss ahead of 2027 regional electric vehicle deployments. *(August 28, 2026; Batteries & EV · Japan · Toyota Motor, Honda Motor, Panasonic Holdings, Prime Planet Energy & Solutions)*
- [Japan certifies $2.4 billion in battery subsidies to lock in solid-state cell capacity](https://eastasiabrief.com/batteries-ev/japan-certifies-2-4-billion-battery-subsidies-lock-solid-65) — The Ministry of Economy, Trade and Industry approved funding for 12 manufacturing projects by Toyota, Nissan, and Panasonic to expand domestic cell production… *(August 28, 2026; Batteries & EV · Japan · Toyota Motor, Nissan Motor, Panasonic Holdings, Subaru Corporation, Mazda Motor)*
- [Japan Separator Makers Accelerate Ceramic-Coated and Solid-State Film Expansion](https://eastasiabrief.com/batteries-ev/japan-separator-makers-accelerate-ceramic-coated-solid-state-film-46) — Asahi Kasei and Toray are retooling production lines toward high-heat ceramic films and solid-electrolyte substrates to secure margins against standard… *(August 28, 2026; Batteries & EV · Japan · Asahi Kasei Corporation, Toray Industries)*
- [Panasonic Optimizes 4680 Battery Cell Yields at Wakayama Plant in Japan](https://eastasiabrief.com/batteries-ev/panasonic-optimizes-4680-battery-cell-yields-wakayama-plant-japan-23) — The Japanese cell manufacturer improves dry electrode coating lines and tabless winding processes to stabilize commercial shipments for primary automotive… *(August 28, 2026; Batteries & EV · Japan · Panasonic Holdings, Panasonic Energy, Tesla)*

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