Hokkaido Should Be Japan's EV Special Zone Vol.2 — Sodium-Ion Batteries: The Cold-Climate Game Changer

About the author dosanko_tousan. 50-year-old stay-at-home dad from Iwamizawa, Hokkaido. Independent AI alignment researcher (GLG Network · Zenodo DOI: 10.5281/zenodo.18691357). This series is my tribute to Hokkaido. Previous installment : Vol.1 — Cold-Climate Battery Physics & The "Five Arrows" Policy Framework Introduction: Vol.1's Conclusion and the Next Question Vol.1 established a clear physical fact. Lithium-ion battery ionic conductivity drops to 12.6% of room temperature performance at -20°C. In NAF real-world driving tests at -31°C, even the best-performing vehicles lost -29% of range. This is a fundamental limitation of lithium-ion chemistry. So — what if we changed the material itself? CATL's second-generation sodium-ion battery "Naxtra," announced in 2024, is rated to maintain 90% of discharge capacity at -40°C . Li batteries lose up to -29% at -31°C. Na batteries claim less than -10% loss at -40°C. This isn't magic. It's electrochemical necessity. This article explains the