Rechargeable Li–CO₂ batteries are deemed to be attractive energy storage systems, as they can effectively inhale and fix carbon dioxide and possess an extremely high energy density. Unfortunately, the irreversible decomposition of the insoluble and insulating Li₂CO₃ results in awful electrochemical performance and inferior energy efficiency of Li–CO₂ batteries. Furthermore, the low energy efficiency will exacerbate the extra waste of resources. Therefore, it is vital to design novel and efficient catalysts to enhance the battery performance. Herein, a facile, one-step strategy is introduced to design cross-linked, ultrathin K_0.5MnO₂ nanoflowers combined with CNTs (K_0.5MnO₂/CNT) as a highly efficient cathode for Li–CO₂ batteries. Impressively, the Li–CO₂ battery based on the K_0.5MnO₂/CNT cathode achieves a low overpotential (1.05 V) and a high average energy efficiency (87.95%) at a current density of 100 mA g⁻¹. Additionally, the K_0.5MnO₂/CNT cathode can steadily run for over 100 cycles (overpotential < 1.20 V). Moreover, a low overpotential of 1.47 V can be obtained even at a higher current density of 1000 mA g⁻¹, indicating the superior rate performance of K_0.5MnO₂/CNT. This strategy offers new insight and guidance for the development of low-cost and high-performance Li–CO₂ batteries.

中文翻译：

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用于高倍率低过电位Li-CO2电池的交联K0.5MnO2纳米花复合材料


可充电Li-CO ₂ 电池被认为是有吸引力的储能系统，因为它们可以有效地吸入和固定二氧化碳，并具有极高的能量密度。不幸的是，不溶且绝缘的Li ₂ CO ₃ 的不可逆分解导致Li-CO ₂ 电池的电化学性能较差且能量效率较低。此外，能源效率低下还会加剧资源的额外浪费。因此，设计新颖高效的催化剂以提高电池性能至关重要。在此，引入了一种简便的一步策略来设计与碳纳米管结合的交联超薄 K _0.5 MnO ₂ 纳米花（K _0.5 MnO ₂ /CNT）作为 Li-CO ₂ 电池的高效阴极。令人印象深刻的是，基于K _0.5 MnO ₂ /CNT阴极的Li-CO ₂ 电池实现了低过电位（1.05 V）和高平均能量效率(87.95%) 在电流密度为 100 mA g ⁻¹ 时。此外，K _0.5 MnO ₂ /CNT 阴极可以稳定运行超过 100 个周期（过电势 < 1.20 V）。此外，即使在1000 mA g的较高电流密度下也能获得1.47 V的低过电位 ⁻¹ ，表明K _0.5 MnO ₂ 电池的开发提供了新的见解和指导。