The sluggish kinetics of air electrodes largely limits the practical applications of metal–air batteries. At present, preparing single-atom catalysts confined in ultrathin N-doped porous carbon (NPC) with a high surface area remains a challenge. Herein, a facile strategy by complexation of biomass and metal ions combined with the gas-foaming method was used to synthesize substantial Co–N₄ active sites on ultrathin NPC with a super-high specific surface area of 1977.9 m² g⁻¹. The catalyst owns brilliant oxygen reduction reaction properties with higher half-wave potential of 0.863 V and faster kinetics process (68.3 mV dec⁻¹) than those of Pt/C (0.856 V and 80.46 mV dec⁻¹, respectively). Remarkably, it exhibits distinguished reversibility with a high initial cycle efficiency of 60.8% and satisfactory stability when used in Zn–air batteries. Moreover, the assembled Al–air battery displays preeminent discharge performance with ultrahigh power density (494 mW cm⁻²) and energy density (2387 W h kg⁻¹) at 200 mA cm⁻². This study opens a new avenue to fully utilize biomass for constructing Co single-atom catalysts for metal–air batteries.

中文翻译：

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高性能金属-空气电池通过生物量络合策略 在超薄N掺杂多孔碳上形成Co单原子†

空气电极的动力学迟缓在很大程度上限制了金属空气电池的实际应用。目前，制备受限于具有高表面积的超薄N掺杂多孔碳（NPC）的单原子催化剂仍然是一个挑战。在此，通过生物质和金属离子的络合与气体发泡方法的简便策略，在具有1977.9 m ² g ^-1的超高比表面积的超薄NPC上合成了大量的Co-N ₄活性位点。与Pt / C（0.856 V和80.46 mV dec ^-1）相比，该催化剂具有出色的氧还原反应性能，半波电势更高，为0.863 V，动力学过程更快（68.3 mV dec ^-1）。， 分别）。值得注意的是，当用于锌空气电池时，它具有出色的可逆性，具有60.8％的高初始循环效率和令人满意的稳定性。此外，组装好的铝空气电池在200 mA cm ^-2的超高功率密度（494 mW cm ^-2）和能量密度（2387 W h kg ^-1）下表现出卓越的放电性能。这项研究开辟了一条新途径，可以充分利用生物质来构建金属-空气电池用的Co单原子催化剂。