Nitrogen doping boosted aqueous Zn-CO2 batteries producing methane and electricity simultaneously

Abstract

Aqueous Zn-CO2 batteries (AZCBs) are limited by low power density and inefficient CO2 conversion. Herein, we report a nitrogen-doped Cu-based metal-organic framework (N-Cu-MOF) cathode that promotes electrochemical CO2 reduction to CH4 with a remarkable selectivity of 96%, while improving battery performance delivering a peak power density of 6.1 mW cm−2 and a current density of 15.0 mA cm−2 over 720 hours. Specifically, nitrogen incorporation modulates the Cu+/Cu2+ electronic structure and strengthens p-d orbital coupling between active sites and reaction intermediates, facilitating the potential-determining *CO→*CHO hydrogenation step.