Synergistic Co‐Recycling: Selective Oxidation of Polyethylene to Dicarboxylic Acids over Spent LiCoO ₂ Cathodes

Abstract The escalating production of lithium‐ion batteries and plastics poses critical challenges to environmental integrity and resource sustainability. Here, we report a synergistic co‐recycling strategy for spent lithium cobalt oxide (LCO) cathodes and waste polyethylene (PE), leveraging the catalytic properties of LCO to oxidize PE into high‐value dicarboxylic acids. Through a combination of density functional theory calculations, electron spin resonance, and in situ infrared spectroscopy, we reveal that lithium‐deficient LCO undergoes a spin‐state transition of Co 3+ to a high‐spin state, facilitating the activation of oxygen and the generation of singlet oxygen. This reactive oxygen species drives the selective oxidation of PE via hydrogen atom transfer, achieving dicarboxylic acid yields of up to 77.5 wt%, markedly exceeding previous benchmarks. Validation with real‐world plastic waste and spent batteries underscores the feasibility of this approach, presenting a sustainable paradigm‐shift solution for the efficient management of lithium‐ion batteries and plastic waste in a circular economy.