Spent Battery-to-Catalyst: Asymmetric Mn–O Motifs Boost Oxygen Activation for Upgrading Polystyrene to Aromatic Oxygenates

The rapid expansion of global lithium-ion battery production has positioned spent batteries as a critical challenge in resource sustainability and environmental stewardship. Breaking from conventional recycling paradigms that focus solely on metal ion/oxide recovery, this study pioneers an innovative inorganic-organic solid waste co-recycling system. We demonstrate the catalytic potential of spent lithium manganese oxide (LMO) materials through their good oxidation properties to upcycle waste polystyrene (PS) into value-added benzoic acid (BA). Mechanistic investigations reveal that Li⁺ polarization induces asymmetric Mn³⁺-O-Mn⁴⁺ coordination in the LMO structure, facilitating lattice oxygen activation and oxygen vacancy formation. These structural modifications enable efficient O₂ conversion into reactive superoxide radicals (^•O₂^-), which drive the selective oxidative cleavage of PS chains. The optimized system achieves an exceptional 88% solid conversion with ∼70% BA selectivity at a low temperature of 150 °C within 1 h. The dual waste-stream remediation approach demonstrates significant potential for sustainable resource recovery at the energy-environment nexus.