When Yoshino Akira, a Japanese chemist, worked on rechargeable batteries in the 1980s, it was with a view to powering portable devices.

His Nobel-prizewinning research led to the first commercial lithium-ion (Li-ion) battery. These now power everything from smartphones to electric vehicles. But the Japanese firms that, building on Mr Yoshino’s work, dominated the Li-ion business early on have lost their edge. CATL, China’s battery giant, and the energy arm of LG, a South Korean group, have eclipsed Japan’s Panasonic as the world’s largest suppliers of ev batteries. Others are catching up in the production of materials and components.

Japanese battery-makers want to regain their rightful place at the head of the pack. To do so they are betting on solid-state batteries. These still shuttle lithium ions between the anode and the cathode to charge and discharge, but the electrolyte where this shuttling happens is solid not liquid. That makes the batteries more stable and potentially more powerful. It also dispenses with the need for bulky cooling systems, required for fast-charging Li-ion systems. Cars equipped with solid-state batteries could be lighter, which increases range.