Extraction of Co and Li2CO3 from cathode materials of spent lithium-ion batteries through a combined acid-leaching and electro-deoxidation approach

Abstract

Recycling of the spent LIBs to extract Li and Co not only offers raw materials for batteries but also lays a sustainable way for battery development. Herein, we adopt a route combining hydrometallurgical and pyro-electrochemical routes to extract Li₂CO₃ and Co powder from the spent LIBs of cell phones. The LiCoO₂-based cathode materials were firstly dissolved in H₂SO₄ solution containing H₂O₂ as the reductant, and the optimal conditions for attaining a high extraction rate of 99% were studied. After that, the precipitated Co(OH)₂ was calcinated in air under 500 °C to generate Co₃O₄ which was thereafter electrochemically converted into Co powder and oxygen in molten Na₂CO₃-K₂CO₃. Overall, the hybrid method employing both hydro- and pyro-route provides an effective pathway to recover both Li₂CO₃ and Co powder from spent LIBs.

Keywords: Electrochemical reduction; Li(2)CO(3); LiCoO(2); Molten salt; Recycling; Spent lithium-ion batteries.