An effective strategy: Glycine enables direct regeneration of retired LiFePO4 cathode materials

Direct regeneration of spent LiFePO 4 (SLFP) cathode materials is crucial for the sustainable development of new energy vehicles and other energy storage sectors. However, challenges persist in conventional regeneration technology, including severe secondary pollution, low economic efficiency, and a complex regeneration process. Herein, a direct regeneration strategy for SLFP is proposed through a water bath approach, wherein the synergistic interplay between Glycine as the reducing agent and Li 2 CO 3 as the lithium source profoundly influences the regeneration of the SLFP. The direct regeneration mechanism reveal that the synergistic interaction of the reducing agent and the lithium source contribute to facilitating re-lithiation and lattice restoration, wherein Glycine as an electron donor to create a reductive environment to transform Fe(III) into Fe(II) and Li 2 CO 3 as the lithium source is synchronously reintroducing to repair the Fe Li anti-site defects in the lattice, thereby achieving the regeneration LFP (RLFP). Moreover, the nitrogen that derives from the amino groups in Glycine is doped into the carbon layer of the RLFP, offering more active sites to enhance Li + migration kinetics, thereby endowing the RLFP with excellent rate capability. The RLFP demonstrates excellent electrochemical performance with an initial discharge capacity of 155.7 mAh g −1 at 0.1C and capacity retention of 92% after 200 cycles at 0.5C. This strategy inspires novel insights into the in situ direct regeneration of the SLFP cathode materials.