The recycling of spent lithium-ion batteries (LIBs) is a crucial issue that has engaged extensive attention worldwide, along with the rapidly increasing usage of lithium-ion batteries. State-of-art recycling approaches, in terms of chemical leaching, have imperfections such as excessive chemical consumption, tedious recycling procedure and aggravated secondary pollution. In this research, a green and closed-loop route for the recycling of spent LiFePO₄ involving oxidation leaching is demonstrated. By properly adjusting or controlling the leaching parameters, the leaching efficiency of lithium is up to 97.6% with the introduction of hydrogen peroxide, which is facilitated to achieve the transformed high-purity lithium carbonate and iron phosphate. The oxidation reaction mechanisms are clarified through thermodynamic and kinetic analyses, which identified that the oxidation leaching reaction is co-controlled by the internal diffusion and chemical reaction. Consequently, LiFePO₄ cathode materials are regenerated by utilizing the obtained raw materials, as expected, which deliver superior cycling stability with less than 1% of capacity loss after 300 cycles and excellent rate performances. This research embodies the possibility of efficient recycling of LiFePO₄ from spent lithium-ion batteries based on the principles of green chemistry that is possibly committed to the sustainability of the lithium-ion battery industry.

中文翻译：

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实现从废锂离子电池中可持续回收 LiFePO4

随着锂离子电池使用量的迅速增加，废旧锂离子电池（LIB）的回收利用是一个受到全球广泛关注的关键问题。现有的化学浸出回收方法存在化学物质消耗过多、回收过程繁琐、二次污染加重等缺陷。本研究提出了一条绿色闭环循环利用废磷酸铁锂_4的路线涉及氧化浸出被证明。通过适当调整或控制浸出参数，在引入过氧化氢的情况下，锂的浸出率可达97.6%，有利于实现高纯度碳酸锂和磷酸铁的转化。通过热力学和动力学分析阐明了氧化反应机理，确定了氧化浸出反应由内部扩散和化学反应共同控制。因此，正如预期的那样，利用所获得的原材料对LiFePO ₄正极材料进行了再生，其具有优异的循环稳定性，300次循环后容量损失小于1%，并具有优异的倍率性能。该研究体现了磷酸铁锂高效回收利用的可能性₄从废旧锂离子电池中提取基于绿色化学的原则，可能致力于锂离子电池行业的可持续发展。