CO2- tolerant CuFe2O4 as Bifunctional Electrocatalyst for Transition from Rechargeable Li-O2 to Li-CO2 Batteries

Abstract

CO2-tolerant rechargeable Lithium-Air batteries are seen as a high-performing alternative to Li-ion batteries. They utilize O2 from the air, reducing it at the cathode to form lithium peroxide (Li2O2) during discharge which is then oxidized to form lithium-metal and freeing O2 during charging. Most of the present studies involve pure O2 as the cathode material instead of aerial O2, which has a stiff-challenge due to atmospheric CO2 which produces Li2CO3 during discharge, posing a resistive load on the battery if not re-oxidized on charging. Ideally, presence of CO2 should enhance the charge-storage capacity if it is cycled reversibly. Thus, present research aims at taking advantage of both O2 and CO2 by employing metallic Cu on CuFe2O4 catalyst, synthesized from a one-step auto-combustion route. The Cu metal present in the catalyst leads to a low surface-area, yet the catalyst demonstrates excellent oxygen reduction reaction and moderate oxygen evolution reaction activity. excellent CO2 reduction reaction activity, oxidizing both the Li2O2 and the Li2CO3 during charge in both 10% CO2 and 100% CO2 atmospheres. The fabricated Li-CO2 battery operates for practical application, suggesting the suitability of the catalyst for the transition from practical Li-O2 battery to Li-Air battery.