Recycling spent lithium-ion batteries can close the strategic metal cycle while reducing ecological and environmental footprints of the batteries. However, fewer efforts have been made for the recycling of spent LiFePO₄ batteries owing to their relatively lower value than the batteries containing cobalt and nickel. In addition, excess acids are required to extract lithium from the olivine-structured LiFePO₄. Herein, we report a paired electrolysis approach employing LiFePO₄ as both the anode and the cathode, and molten carbonate as the electrolyte to reclaiming the retired LiFePO₄ batteries. The paired electrolysis converts LiFePO₄ to Fe at the cathode and to Fe₃O₄ at the anode while releasing Li⁺ and PO₄³⁻ into the molten salt. In this scenario, the electric power drives the redox reactions and thereby separates Li, Fe, and PO₄³⁻. The recovery rate of Li reaches over 95.2%. Overall, the paired electrolysis cell containing dual LiFePO₄ electrodes employs electrons to break down the olivine structure, which paves a green pathway to recycle various end-of-life LIBs with minimized secondary waste and energy consumption.

中文翻译：

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一种成对的电解方法，用于在未分开的熔盐电池中回收废磷酸铁锂电池

回收废旧锂离子电池可以关闭战略金属周期，同时减少电池的生态和环境足迹。然而，由于废旧的LiFePO ₄电池的价值比含钴和镍的电池的价值相对较低，因此为回收废旧的锂电池所做的工作较少。另外，需要过量的酸以从橄榄石结构的LiFePO _4中提取锂。在此，我们报道了一种成对的电解方法，该方法采用LiFePO ₄作为阳极和阴极，并使用熔融碳酸盐作为电解质来回收已淘汰的LiFePO ₄电池。配对电解将LiFePO ₄在阴极转换为Fe，并转换为Fe ₃ O ₄在阳极上释放Li ⁺和PO ₄ ^3-到熔融盐中。在这种情况下，电力驱动氧化还原反应，从而分离Li，Fe和PO ₄ ^3-。锂的回收率达到95.2％以上。总体而言，包含双LiFePO ₄电极的成对电解池利用电子分解橄榄石结构，这为绿色环保的道路铺平了道路，可回收各种报废的LIB，从而将二次废物和能源消耗降至最低。