Facile\nSynthesis of Birnessite δ‑MnO₂ and Carbon\nNanotube Composites as Effective Catalysts for\nLi-CO₂ Batteries

Abstract

Li-CO₂ batteries are one type of promising energy storage\nand conversion devices to capture and utilize the greenhouse gas CO₂, mitigating global temperature rise and climate change. Catalysts\nthat could effectively decompose the discharge product, Li₂CO₃, are essential for high-performance Li-CO₂ batteries. Benefiting from the interconnected porous structure,\nfavorable oxygen vacancy, and the synergistic effects between the\ncarbon nanotube (CNT) and layered birnessite δ-MnO₂, our Li-CO₂ cathodes with the as-prepared CNT@δ-MnO₂ catalyst can efficiently afford a large reaction surface\narea and abundant active sites, provide sufficient electron/Li⁺ transport pathways, and facilitate electrolyte infiltration\nand CO₂ diffusion, demonstrating low overpotential and\nsuperior cycling stability, which have been proven by both experimental\ncharacterization and theoretical computation. It is expected that\nthis work can provide guidance for the design and synthesis of high-performance\nelectrochemical catalysts for Li-CO₂ batteries.