tl;dr: Japanese researchers have developed a lithium recycling process that recovers roughly 90% of lithium from used EV batteries, nearly double conventional methods, by substituting recovered lithium hydroxide for sodium hydroxide when processing "black mass." The technique also reportedly cuts carbon emissions by about 40% versus traditional recycling. Scaling remains a hurdle, as only ~14% of Japan's used lithium-ion batteries currently enter formal recycling channels, though expanded production is planned by 2027.