Breaking the Capacity‐Reversibility Linear Trade‐Off in Li–O 2 Batteries via Amorphous Non‐Precious High‐Entropy Alloy Catalysts

ABSTRACT Lithium–oxygen (Li–O 2 ) batteries suffer from sluggish reaction kinetics and rely on precious metal‐based catalysts to facilitate the reaction process. Despite being effective, these costly catalysts would inevitably introduce a critical trade‐off between capacity and reversibility, compromising the high energy density advantage of Li–O 2 batteries. In this study, we have designed an amorphous non‐precious MnFeCoNiCu high‐entropy alloy (A‐HEA) catalyst via a mild liquid‐phase reduction strategy to break the above inherent linear trade‐off. The amorphous and porous structure of A‐HEA could provide a large electrochemical active surface area, diluting the local current density to promote the solution‐mediated discharge pathway. This enables the growth of large‐sized Li 2 O 2 to deliver a discharge capacity reaching 10.8 mAh cm −2 . Additionally, the multielemental synergistic electron redistribution of A‐HEA optimizes the d ‐band center to strengthen the LiO 2 adsorption and weaken the O─O bonding, reducing the overpotential to 0.75 V and extending the battery lifetime by 4−5 times compared to the crystalline counterparts. Importantly, the A‐HEA can be produced at a scale of over 100 g and works well in Li–O 2 pouch cells with a rate capability up to 400 mA and an energy density of 754 Wh kg −1 (560 Wh kg −1 even at −30°C).