A holistic review on the direct recycling of lithium-ion batteries from electrolytes to electrodes

Abstract

Lithium-ion batteries (LIBs) present a global challenge in managing their end-of-life (EOL) issues. As LIB's raw materials are critical and valuable, they are considered as a secondary resource. The volume of publications and patents on LIB recycling has significantly increased, rising a 32% annual growth, compared to a 4% increase in all scientific chemical literature within a decade, reflecting the emergence of this research topic. In a circular economy context, achieving high recycling efficiency of all LIB components and reusing recycled raw materials for battery production are essential. The increase in recycling efficiency is further promoted by government regulations aiming for carbon neutrality and sustainable society with lower environmental impacts. Conventional and destructive recycling methods, pyrometallurgy and hydrometallurgy, focusing on specific metals are insufficient to achieve these goals. Therefore, this review discusses the emerging topic of direct recycling, which recovers, regenerates, and reuses main battery components: electrolyte as well as negative and positive electrodes to fabricate new LIBs. Although this approach may complicate the process, it significantly increases recovery rates, prevents component destruction, and minimizes losses. This critical review offers ideas and methods to provide new perspectives on recycling the main components of LIBs.