Clean and efficient lithium recovery from waste electrolytes via an environmentally short process

Low-cost and environmentally friendly recycling methods can incorporate strategic elements from discarded lithium-containing aluminum electrolytes (LiAE), which is crucial for alleviating resource shortages and environmental footprint. This study aims to develop a method for the comprehensive utilization of LiAE through lowtemperature leaching of calcification. Unlike traditional high-temperature acidification roasting/ transformation processes (320-850 degrees C), the calcification leaching method only involves one-step leaching and avoids high heat energy consumption. Besides, this low-temperature calcification method chemically destroys the crystal structure of metal fluorides (Li, Na, K, etc.), ensuring a high leaching rate while ensuring an alkaline environment for lithium extraction from the leaching solution without additional alkaline neutralization. The lithium extraction rate exceeds 96 %, with high-purity Li2CO3 and NaOH prepared. The CaCO3 produced by decalcification has the potential for recycling (in the form of CaO after calcination). Meanwhile, the effects of operating temperature, mass ratio of CaO to LiAE, liquid-solid ratio, and leaching time on the calcium leaching reaction were systematically studied. The economic benefits and creative evaluation of the process were evaluated. Finally, the regenerated LCO prepared from recycled Li2CO3 has been proven to have good electrochemical performance compared to commercial LCO, demonstrating the feasibility of energy storage application. In summary, the comprehensive utilization of LiAE by the calcium leaching method has been proven to be feasible.