Quenching-induced Fe doping on spent cathode materials enhances the oxygen evolution reaction performance

Repurposing spent battery materials into electrocatalysts offers a dual-functional strategy to mitigate environmental burdens and create value-added products. However, developing efficient conversion methods to transform spent cathodes into high-activity, cost-effective catalysts remains a critical challenge. Here, we report a Fe-doped LCO/Co 3 O 4 heterogeneous interface catalyst (Fe-LCO/Co 3 O 4 ) synthesized by quenching the calcinated spent LiCoO 2 (SLCO) in the Fe 3+ solution for promoting the performance of the oxygen evolution reaction (OER). Fe-LCO/Co 3 O 4 features outstanding OER activity, including a low overpotential of 312 mV at 10 mA cm −2 , a Tafel slope of 34 mV dec −1 , and remarkable stability exceeding 1000 h, better than the majority of cobalt-based electrocatalysts. Experimental results and density functional theory reveal that Fe ions coupled with LCO/Co 3 O 4 heterostructures alter the adsorption configuration of *OH and *O, optimizing binding capabilities and effectively reducing the rate-determining step of *OOH dehydrogenation energy barrier, thereby accelerating the OER. This study introduces a novel strategy for the sustainable reuse of spent cathode materials, providing insights into the rational design of high-performance OER electrocatalysts.