Electrode separation via water electrolysis for sustainable battery recycling

Abstract

Recycling large quantities of lithium-ion batteries facing retirement is pivotal for resource conservation and environmental sustainability. Direct recycling, while offering a promising avenue with reduced waste compared with pyrometallurgy and hydrometallurgy, often involves intricate and long processes. Here we introduce a water electrolysis-induced separation approach, using H2 or O2 gas bubbling to efficiently separate electrode materials from current collectors. The process achieves 99.5% materials recovery with metal impurities <40 ppm within 34 s for LiFePO4 and 3 s for graphite at 10 mA cm−2, with minimal energy consumption of 11 and 1.1 kJ kgcell−1. Moreover, this approach accommodates various electrode types, encompassing cathodes and anodes from spent batteries or manufacturing scraps. The subsequent dry electrode manufacturing process with lithium replenishment substantially enhances environmental sustainability by eliminating the use of N-methyl pyrrolidone, while maintaining performance through the effective mixing of active materials and conductive agents. An EverBatt analysis underscores a remarkable reduction in energy consumption and waste generation compared with industrially adopted recycling methods. This finding provides an efficient and sustainable solution for battery recycling while ensuring high-quality materials production. Current battery recycling processes face sustainability challenges. Using gas evolution in water electrolysis, this work realizes fast separation of active electrode materials from current collectors before their dry refabrication for electrodes without compromising performance.