Densely populated trimetallic single-atoms for durable low-temperature flexible zinc-air batteries.

The fundamental challenge of trimetallic single-atoms catalysts stems from the difficulty in supporting the coexistence of different metals with their unique physicochemical features. Here, the trimetallic single-atoms electrocatalyst is constructed as a model system to explore electrocatalytic ORR/OER. The tri-metal (Fe, Co, and Ni) single-atoms loaded on nitrogen-carbon framework exhibits superior ORR/OER kinetics (E 1/2 = 0.927 V, E j =10 = 1.56 V). The flexible zinc-air batteries generate excellent power density and durability (62 mW cm−2 and 200 h at −15 °C, 291.2 mW cm−2 and 250 h at room temperature). Density functional calculations confirm that the trimetallic synergy effect outperform mono- and bimetallic effects, yielding adsorption strength close to 0. This paper describes an intuitionistic descriptor where ΔE OH* displays a volcano relationship with ORR overpotential, and establishes a generalized strategy for efficient bifunctional oxygen electrocatalyst while comprehensively understanding the structure-mechanism-activity relationship. [Display omitted] • Tri-metal incorporated nitrogen-carbon catalysts possesses high density and well dispersed tri-metal single atom sites. • Fe 3% Co 3% Ni 9% -NC1000 display outstanding ORR/OER performance. • The descriptor ΔE OH* displays a volcano relationship with ORR overpotential. • Flexible zinc-air batteries assembled with Fe 3% Co 3% Ni 9% -NC1000 generate superior power density and durability. [ABSTRACT FROM AUTHOR]