A simple, green and effective method, which combined lithium iron phosphate battery charging mechanism and slurry electrolysis process, is proposed for recycling spent lithium iron phosphate. Li and FePO4 can be separation in anionic membrane slurry electrolysis without the addition of chemical reagent. The leaching efficiency of Li can reach to 98% and over 96% of Fe are recycled as FePO4/C. Kinetics analysis indicates that the surface chemical reaction is the control step during the slurry electrolysis. Additionally, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Electrochemical Impedance Spectroscopy (EIS) characterization and thermodynamic analysis are employed to investigate the leaching mechanism. It is found that the spent LiFePO4 is delithiated and oxidized to FePO4 by the function of e-, which is similar as the LiFePO4 battery charging process. EIS analysis also verify the kinetics results, the charge transfer resistance controlled the leaching process. Finally, a novel process for recovery of spent LiFePO4 is proposed. The recovered Li2CO3 and FePO4/C can be used for resynthesize LiFePO4, and the resynthesized LiFePO4 exhibits reversible capacities of 143.6 mAh g-1 at 1C and high current efficiency, stable cycle performances at 0.1 and 0.5C which meets the basic requirements for reuse.

中文翻译：

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通过阴离子膜浆料电解从废磷酸铁锂正极材料中选择性回收锂和磷酸铁/碳。

提出了一种简单，绿色，有效的方法，将磷酸铁锂电池的充电机理与浆料电解工艺相结合，回收了废磷酸铁锂。Li和FePO4可以在阴离子膜浆料电解中分离，而无需添加化学试剂。Li的浸出效率可以达到98％，超过96％的Fe以FePO4 / C的形式回收。动力学分析表明，表面化学反应是浆料电解过程中的控制步骤。另外，利用X射线衍射（XRD），X射线光电子能谱（XPS），电化学阻抗谱（EIS）表征和热力学分析来研究浸出机理。发现用过的LiFePO4通过e-的作用脱锂化并氧化为FePO4，这类似于LiFePO4电池的充电过程。EIS分析还验证了动力学结果，电荷转移阻力控制了浸出过程。最后，提出了一种回收废LiFePO4的新方法。回收的Li2CO3和FePO4 / C可用于再合成LiFePO4，再合成的LiFePO4在1C时可逆容量为143.6 mAh g-1，电流效率高，在0.1和0.5C时具有稳定的循环性能，满足了重复使用的基本要求。