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

Abstract

CO 2 -tolerant rechargeable Lithium-Air batteries are seen as a high-performing alternative to Li-ion batteries. They utilize O 2 from the air, reducing it at the cathode to form lithium peroxide (Li 2 O 2 ) during discharge which is then oxidized to form lithium-metal and freeing O 2 during charging. Most of the present studies involve pure O 2 as the cathode material instead of aerial O 2 , which has a stiff-challenge due to atmospheric CO 2 which produces Li 2 CO 3 during discharge, posing a resistive load on the battery if not re-oxidized on charging. Ideally, presence of CO 2 should enhance the charge-storage capacity if it is cycled reversibly. Thus, present research aims at taking advantage of both O 2 and CO 2 by employing metallic Cu on CuFe 2 O 4 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 CO 2 reduction reaction activity, oxidizing both the Li 2 O 2 and the Li 2 CO 3 during charge in both 10% CO 2 and 100% CO 2 atmospheres. The fabricated Li-CO 2 battery operates for practical application, suggesting the suitability of the catalyst for the transition from practical Li-O 2 battery to Li-Air battery.