Responsible disposal and recycling are essential for the sustainability of the battery market, which has been exponentially growing in the past few years. Under such a scenario, the recycling of materials of less economic value, but environmentally much more sustainable like LiFePO₄, represents an economic challenge. In this paper an approach to recover used FePO₄ electrodes from calendar aged Lithium-ion (Li-ion) batteries and their reuse in Sodium-ion (Na-ion) cells is proposed. The electrochemical performances of the Na-ion cell are shown to be comparable with previously reported values and, since the electrode can retain the original microstructure and distribution, electrode processing can be avoided. A proof of concept of a NaFePO₄//hard carbon full cell using a very high positive electrode loading optimized for Li-ion batteries (≈14 mg cm⁻²) is shown.

负责任的处置和回收对于电池市场的可持续性至关重要，电池市场在过去几年呈指数级增长。在这种情况下，回收经济价值较低但在环境上更具可持续性的材料（如 LiFePO ₄）是一项经济挑战。在本文中，提出了一种从日历老化的锂离子 (Li-ion) 电池中回收使用过的 FePO ₄电极的方法，并将其重新用于钠离子 (Na-ion) 电池中。钠离子电池的电化学性能与之前报道的值相当，并且由于电极可以保留原始的微观结构和分布，因此可以避免电极加工。NaFePO ₄的概念证明//硬碳全电池使用为锂离子电池优化的非常高的正极负载（≈14 mg cm ^-2）显示。