Rechargeable Li-CO₂ batteries have been studied extensively as an attractive strategy for simultaneous energy storage and CO₂ fixation to address the global environmental and energy crisis. However, state-of-the-art Li-CO₂ systems still suffer from unsatisfactory performance. Here, we successfully exfoliated quinone-based covalent organic frameworks (COFs) into large-scale and ultrathin MnO₂/2,6-diaminoanthraquinone-2,4,6-triformylphloroglucinol (DQTP)-COF-nanosheet (NS) hybrid materials. The obtained ultrathin nanosheets (as thin as 1.87 nm) synergistically integrate quinone-COF-NSs with MnO₂ and serve as powerful cathode catalysts in Li-CO₂ batteries. MnO₂/DQTP-COF-NS-3 has a high discharge capacity of 42,802 mAh/g at 200 mA/g. Additionally, it is durable for higher-stress test with a negligible change of overpotential from 500 to 1,000 mA/g and is discharged/charged rapidly for 120 cycles at 1 A/g. Moreover, the CO₂ activation mechanism is discussed and supported by density functional theory (DFT) calculations. This work may pave a new way for exploring porous crystalline materials as efficient cathode catalysts for Li-CO₂ batteries.

可充电的Li-CO ₂电池已被广泛研究作为一种有吸引力的策略，用于同时进行能量存储和CO ₂固定，以解决全球环境和能源危机。然而，最先进的Li-CO ₂系统仍然具有不能令人满意的性能。在这里，我们成功地将基于醌的共价有机骨架（COFs）剥离成大规模的超薄MnO ₂ / 2,6-二氨基蒽醌-2,4,6-三甲酰间苯三酚（DQTP）-COF-纳米片（NS）杂化材料。所获得的超薄纳米片（薄至1.87 nm）将醌-COF-NS与MnO ₂协同集成，并在Li-CO ₂电池中用作强大的阴极催化剂。的MnO ₂/ DQTP-COF-NS-3在200 mA / g时具有42,802 mAh / g的高放电容量。此外，它在高应力测试中具有很强的耐用性，其过电位从500到1,000 mA / g的变化可忽略不计，并且以1 A / g的速度快速放电/充电120个循环。此外，讨论了CO ₂活化机理并得到密度泛函理论（DFT）计算的支持。这项工作可能为探索多孔晶体材料作为Li-CO ₂电池的有效阴极催化剂铺平了一条新途径。