Rechargeable Zn-air batteries promise safe energy storage. However, they are limited by the redox potential of O₂/O^2- chemistry in an alkaline electrolyte, resulting in low operating voltages and therefore insufficient energy density to compete with lithium-ion batteries. The O₂/O^2- redox potential increases by 0.8 V in an acidic medium, hinting at a way to boost the voltage: an asymmetric electrolyte configuration decoupling acidic and alkaline electrolytes for the air cathode and zinc anode. Such configuration requires a thin and ionically conductive membrane to separate two mutually incompatible electrolytes. Here, we report a Zn ion-exchange membrane with high ionic conductivity of 1.1 mS cm^-1, which prevents acid-base neutralization. The highly reversible O₂/O^2- reaction in the acid is made possible by compositing a cobalt-coordinated porphyrin-based polymeric framework with MXene as a bifunctional electrocatalyst. The asymmetric Zn-air battery operates at voltages up to 1.85 V and cycles for more than 200 h with a material-level energy density of 1350 Wh kg^-1, projected to a high device-level energy density of 50 Wh kg^-1 (coin cell diameter: 20 mm). The asymmetric configuration withstands pressure up to 4 MPa (∼1200 N), demonstrating excellent structural stability for production and practical applications.

可充电锌空气电池有望安全储能。然而，它们受到碱性电解质中_{O 2} /O ^2化学氧化还原电位的限制^{，导致工作电压低，因此}能量密度不足以与锂离子电池竞争。O ₂ /O ^2-氧化还原电位在酸性介质中增加了 0.8 V，暗示了一种提高电压的方法：不对称电解质配置将空气阴极和锌阳极的酸性和碱性电解质解耦。这种配置需要薄的离子导电膜来分离两种相互不相容的电解质。在这里，我们报告了一种具有 1.1 mS cm 高离子电导率的 Zn 离子交换膜^{- 1}，可防止酸碱中和。通过将钴配位的卟啉基聚合物框架与作为双功能电催化剂的 MXene 复合，可以在酸中进行高度可逆的 O ₂ /O ^2-反应。非对称锌空气电池的工作电压高达 1.85 V，循环时间超过 200 小时，材料级能量密度为 1350 Wh kg - 1 ，预计器件级能量密度为^{50 Wh} kg ^{- 1} (纽扣电池直径：20 毫米）。不对称配置可承受高达 4 MPa (∼1200 N) 的压力，在生产和实际应用中展示了出色的结构稳定性。