Rechargeable metal–gas batteries have the promise of exceeding the energy densities of Li-ion batteries. An archetypal metal–gas system is the nonaqueous lithium–oxygen (Li–O₂) battery, which was developed with a view to deploying it in electric vehicles. However, operating this battery comes with substantial challenges that include parasitic chemical reactivity and degrees of electrochemical irreversibility, which contribute to poor charging and cycling. To address these challenges, researchers began exploring new nonaqueous metal–gas battery paradigms by manipulating the underlying O₂ redox behaviour through electrolyte and materials design, using non-Li-metal anodes to change the nature of the solid discharge phase and improve reversibility, and using other gaseous reactants as the cathode. This Review presents the new understanding of nonaqueous gas-to-solid electrochemistry that has emerged from these concerted efforts, along with new hurdles that have been revealed as cells have gradually been reformulated. The ultimate impact of new metal–gas batteries needs to be re-examined for applications beyond electric vehicles that are more amenable to the individual chemistries and performance characteristics.

可充电金属气体电池有望超过锂离子电池的能量密度。原型金属-气体系统是非水锂-氧（Li-O ₂）电池，其开发目的是将其部署在电动汽车中。然而，操作该电池面临着巨大的挑战，包括寄生化学反应性和电化学不可逆度，这导致不良的充电和循环。为了应对这些挑战，研究人员开始通过操纵潜在的O _2来探索新的非水金属-气体电池范例通过电解质和材料设计的氧化还原行为，使用非锂金属阳极来改变固体放电相的性质并提高可逆性，并使用其他气态反应物作为阴极。这篇综述提供了从这些共同努力中产生的对非水气-固电化学的新认识，以及随着细胞逐渐被重新配制而发现的新障碍。对于电动汽车以外的应用，需要对新的金属-气体电池的最终影响进行重新检查，因为电动汽车更适合于各个化学性质和性能特征。