Lithium-oxygen (Li-O2) battery is favored among “beyond lithium-ion” technologies for sustainability because of its exceptional energy density. Major impediments are the poor cycle stability and grievous capacity degradation at high current densities. We address these issues by a “killing two birds with one stone” O2-pressure protocol. It first resolves efficient O2 mass transport at high rates.æ The accelerated reaction kinetics optimizes the composition and growth pathway of discharge products. This protocol secondly achieves protection of Li anodes via densifying corrosion layers on them. Consequently, the battery delivers both ultrahigh discharge capacity (> 9,000 mAh g−1) at 3,000 mA g−1 and excellent cycling stability. Under a dual-strategy effect of high-pressure O2 and artificial protection layers, the battery actualizes over 11-fold increase in cycle life of 5,170 h (2,585 cycles). The strategy opens avenues for advancing Li-O2 batteries towards practical application and confers the extension to other gas-based batteries.