With the termination of the life of the first generation of power batteries, a substantial quantity of lithium iron phosphate (LiFePO₄) batteries necessitates recycling. The mainstream recycling process is lithium leaching with acid leaching systems and cathode material regeneration. However, the binder poly(vinylidene fluoride) (PVDF) and the conductive carbon in the cathode material are not utilized. In this paper, a new two-step recycling process is proposed: (1) an acid-free lithium leaching route using a single component K₂S₂O₈ as a leaching agent and (2) utilizing the residual carbon in the leaching residue to produce Fe₂P₂O₇, which can be used as anodes for batteries, by high-temperature carbothermal reduction of FePO₄. By optimizing the leaching process parameters, 98.9 wt % of the lithium in the cathode material can be selectively released. The electrochemical characteristics of Fe₂P₂O₇ synthesized at various carbothermal reduction temperatures were assessed, revealing that the sample produced at 700 °C exhibited the most favorable electrochemical attributes. Even after 750 cycles at a current density of 1.0 A/g, the catalyst retained a specific capacity of 160 mAh/g. This research introduces an innovative approach for the comprehensive recuperation of all components in recycling LiFePO₄.

中文翻译：

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废磷酸铁锂正极的全组分回收再利用工艺

随着第一代动力电池寿命的终结，大量磷酸铁锂（LiFePO ₄）电池需要回收。主流的回收工艺是采用酸浸系统的锂浸出和正极材料再生。然而，正极材料中没有使用粘合剂聚偏二氟乙烯（PVDF）和导电碳。本文提出了一种新的两步回收工艺：（1）使用单组分K ₂ S ₂ O ₈作为浸出剂的无酸锂浸出路线；（2）利用浸出渣中的残留碳通过FePO ₄的高温碳热还原生产可用作电池负极的Fe ₂ P ₂ O ₇。通过优化浸出工艺参数，可以选择性地释放正极材料中98.9 wt%的锂。对不同碳热还原温度下合成的 Fe ₂ P ₂ O ₇的电化学特性进行了评估，结果表明在 700 °C 下制备的样品表现出最有利的电化学属性。即使在1.0 A/g的电流密度下循环750次后，催化剂仍保持160 mAh/g的比容量。这项研究引入了一种创新方法，用于综合回收 LiFePO ₄中的所有成分。