Stable and efficient bifunctional electrocatalyst for air electrode is still of challenge for rechargeable zinc-air batteries (ZABs). Here, we report an atomic layer oxygen defect cobalt oxides (Co₃O_4-x) nanosheets (1 nm) as efficient electrocatalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Due to the atomic layer nanosheets, more oxygen defects are formed during plasma treatment enabling effective OER catalysis with overpotential of only 309 mV, which is lower compared to benchmarking IrO₂ (313 mV). Meanwhile, a Pt-like ORR activity is achieved for Co₃O_4-x due to the atomic layer nanosheets with highly exposed active sites and loosened binding strength between Co³⁺ and O₂/OH⁻. The battery performance of Co₃O_4-x nanosheets is 1.7 times higher than that of Pt/C-IrO₂ based ZABs. Besides, Co₃O_4-x nanosheets exhibit undetectable degradation in battery performance after galvanostatic discharge-charge with 5 mA cm⁻² for 150 h implying the superior stability of the atomic layer Co₃O_4-x nanosheets. All-solid-sate ZABs fabricated from Co₃O_4-x nanosheets perform an impressive power density of 57 mW cm⁻² and stable galvanostatic discharge-charge voltage for 2 h demonstrating that Co₃O_4-x nanosheets can be utilized as air electrode for practical application.

对于可充电锌空气电池（ZAB）而言，稳定高效的用于空气电极的双功能电催化剂仍然是挑战。在这里，我们报告原子层氧缺陷氧化钴（Co ₃ O _4-x）纳米片（1 nm）作为氧还原反应（ORR）和氧释放反应（OER）的有效电催化剂。由于原子层纳米片的存在，在等离子体处理过程中会形成更多的氧缺陷，从而实现有效的OER催化，其超电势仅为309 mV，与基准IrO ₂（313 mV）相比更低。同时，由于原子层纳米片具有高度暴露的活性位点和松散的Co之间的结合强度，Co ₃ O _4-x达到了Pt样的ORR活性。³⁺和O ₂ / OH ^- 。Co ₃ O _4-x纳米片的电池性能是Pt / C-IrO ₂基ZAB的1.7倍。此外，Co ₃ O _4-x纳米片在用5 mA cm ^-2进行恒流放电充电150小时后表现出不可检测的电池性能下降，这表明Co ₃ O _4-x纳米片具有优异的稳定性。由Co ₃ O _4-x纳米片制成的全固态ZAB具有惊人的57 mW cm ^-2的功率密度稳定的恒电流充放电电压2 h证明了Co ₃ O _4-x纳米片可用作实际应用的空气电极。