Tailoring the Discharge Reaction in Li-CO2 Batteries through Incorporation of CO2 Capture Chemistry

Abstract

Summary The search for viable end-uses of CO2 has motivated considerable research into CO2 utilization in energy storage devices such as alkali metal-based O2/CO2 and -CO2 batteries. However, efforts have been stymied by the low electrochemical activity of CO2 in most organic media. In this work, we report a mediated CO2 capture and conversion process, based on amine (e.g., 2-ethoxyethylamine) chemisorption, which provides a new electrolyte system for facilitating the discharge reaction in Li-CO2 batteries. Our results indicate that electrochemical reduction of CO2-loaded amines proceeds at significantly higher discharge potentials (∼2.9 V versus Li/Li+) compared with physically dissolved CO2, which is inactive in the amine's absence. The discharge reaction forms solid-phase Li2CO3 as the primary discharge product and yields high discharge capacities (>1,000 mAh/gc), highlighting the coupling of CO2 capture chemistry to nonaqueous batteries as a promising approach for the design and manipulation of CO2 conversion reactions.