Comparative Study of Li-CO₂ and Na-CO₂ Batteries with Ru@CNT as a Cathode Catalyst

Alkali metal-carbon dioxide (Li/Na-CO₂) batteries have generated widespread interest in the past few years owing to the attractive strategy of utilizing CO₂ while still delivering high specific energy densities. Among these systems, Na-CO₂ batteries are more cost effective than Li-CO₂ batteries because the former uses cheaper and abundant Na. Herein, a Ru/carbon nanotube (CNT) as a cathode material was used to compare the mechanisms, stabilities, overpotentials, and energy densities of Li-CO₂ and Na-CO₂ batteries. The potential of Na-CO₂ batteries as a viable energy storage technology was demonstrated.