Recovery and regeneration of LiFePO₄ from spent lithium-ion batteries via a novel pretreatment process

The recycling of spent LiFePO₄ batteries has received extensive attention due to its environmental impact and economic benefit. In the pretreatment process of spent LiFePO₄ batteries, the separation of active materials and current collectors determines the difficulty of the recovery process and product quality. In this work, a facile and efficient pretreatment process is first proposed. After only freezing the electrode pieces and immersing them in boiling water, LiFePO₄ materials were peeled from the Al foil. Then, after roasting under an inert atmosphere and sieving, all the cathode and anode active materials were easily and efficiently separated from the Al and Cu foils. The active materials were subjected to acid leaching, and the leaching solution was further used to prepare FePO₄ and Li₂CO₃. Finally, the battery-grade FePO₄ and Li₂CO₃ were used to re-synthesize LiFePO₄/C via the carbon thermal reduction method. The discharge capacities of re-synthesized LiFePO₄/C cathode were 144.2, 139.0, 133.2, 125.5, and 110.5 mA·h·g⁻¹ at rates of 0.1, 0.5, 1, 2, and 5 C, which satisfies the requirement for middle-end LiFePO₄ batteries. The whole process is environmental and has great potential for industrial-scale recycling of spent lithium-ion batteries.