Targeted anchoring of Cu sites in imine-based covalent organic frameworks as catalytic centers for efficient Li-CO2 battery

Abstract

The lithium-carbon dioxide (Li-CO2) batteries have attracted much attention due to their high theoretical energy density and reversible CO2 reduction/precipitation process. However, the wide bandgap insulating discharge product Li2CO3 is difficult to decompose leading to large polarization or even death of the battery seriously hindering the practical application of Li-CO2 batteries. The covalent organic framework (COF) material properties, which can support the construction of multiphase catalytic systems, have great potential in the fields of CO2 enrichment and electrocatalytic reduction. In this paper, the excellent redox properties of excess metal were utilized to introduce Cu metal into the imine-based COF to form Cu-O, N sites as the active sites for CO2 oxidation and precipitation. The electrochemical performance of the Cu metal in Li-CO2 batteries was investigated, and the prepared batteries were able to cycle stably at a current density of 200 mA g-1 for more than 1100 h. COF structural sites can be anchored by metal Cu sites to form Cu-O, N active centers for CO2 oxidation and reduction processes, this study provides a new experience for Li-CO2 batteries to be applied to long-term, stable, and commercial applications.