Unique Hierarchically Structured High‐Entropy Alloys with Multiple Adsorption Sites for Rechargeable Li–CO2 Batteries with High Capacity

Abstract Lithium–carbon dioxide (Li–CO 2 ) batteries offer the possibility of synchronous implementation of carbon neutrality and the development of advanced energy storage devices. The exploration of low‐cost and efficient cathode catalysts is key to the improvement of Li–CO 2 batteries. Herein, high‐entropy alloys (HEAs)@C hierarchical nanosheet is synthesized from the simulation of the recycling solution of waste batteries to construct a cathode for the first time. Owing to the excellent electrical conductivity of the carbon material, the unique high‐entropy effect of the HEAs, and the large number of catalytically active sites exposed by the hierarchical structure, the FeCoNiMnCuAl@C‐based battery exhibits a superior discharge capability of 27664 mAh g −1 and outstanding durability of 134 cycles as well as low overpotential with 1.05 V at a discharge/recharge rate of 100 mA g −1 . The adsorption capacity of different sites on the HEAs is deeply understood through density functional theory calculations combined with experiments. This work opens up the application of HEAs in Li–CO 2 batteries catalytic cathodes and provides unique insights into the study of adsorption active sites in HEAs.