Fast-Kinetic and Stable Li-CO2 Batteries Driven by an Oxygen-Defective Cu2O-ZnNb2O6 Catalyst Through d-p-d Orbital Hybridization.

Lithium-carbon dioxide (Li-CO2) batteries provide a distinctive energy storage route by directly capturing and converting CO2. However, their development is plagued by sluggish reaction kinetics and poor cycling stability. Although catalysts are indispensable to mitigate these issues, achieving both low polarization and durable high-rate cycling remains a longstanding challenge. Here, we engineer a cost-effective copper (I) oxide (Cu2O)-zinc niobate (ZnNb2O6) heterostructured catalyst featuring oxygen vacancies and strong d-p-d interfacial orbital hybridization to overcome these bottlenecks. Multimodal in situ spectroscopies, synchrotron characterization, and computational studies reveal that this configuration constructs enriched active sites and continuous interfacial charge-transfer channels, promoting the formation of finely dispersed lithium carbonate (Li2CO3) with elongated Li─O bonds. These synergetic effects accelerate CO2 conversion kinetics and reduce the decomposition barrier of discharge products, enabling highly reversible cycling even under high rates. The resulting Li-CO2 battery thus operates stably for 5400 h at 100 mA g-1 and maintains a low overpotential of 1.6 V at 1000 mA g-1, with a pouch cell retaining robust cyclability over 484 cycles at the same high rate, demonstrating record performance that surpasses prior reported results. This work opens a promising pathway for designing high-performance catalysts for sustainable batteries with robust performance.