Closed-loop Lithium Recovery from Ternary Lithium-Ion Batteries: Dual Utilization of Waste Materials

With the flourish of electric vehicles, spent lithium-ion batteries are piling up. The unrecycled batteries will waste valuable metals, such as lithium, nickel, and cobalt, and harm the environment. Using spent cathode materials (SNCMs) as electrodes, this study develops an "SLNCM//SNCM" rocking-chair capacitive deionization (RCDI) system for efficiently prioritizing lithium recovery from the leachate of spent batteries. The system achieves a continuous and selective lithium extraction of 4.90 mmol g^-1 per cycle, and the Li⁺ purity in the receiving solution reaches up to 95.82%, with a lithium recovery rate of approximately 90.9% for the entire extraction process. The study also designs a closed-loop recycling strategy, by dual utilization of SNCMs as electrodes and leachate, achieving "self-recycling" of waste materials, based on the "SLNCM//SNCM" RCDI system. The system offers lower energy consumption, higher efficiency, and superior cycling stability, and economic analysis shows a positive profit, highlighting the feasibility and sustainability of the process. This eco-friendly technology aligns with circular economy and sustainable development principles, offering an efficient solution for recycling spent batteries and reusing resources.