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

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.