ZnO electrocatalyst integrated onto carbon paper for efficient non-aqueous Li-O<sub>2</sub> batteries.

Abstract

The development of high-performance lithium-oxygen (Li-O₂) batteries is hindered by challenges including high overpotential and limited cycle life. In this paper, we report the cost-effective and scalable synthesis of a ZnO electrocatalyst directly integrated onto carbon paper <i>via</i> a simple dipping and thermal treatment method. The resulting ZnO-on-carbon composite (ZnO on P50) was employed as the cathode in a non-aqueous Li-O₂ battery. Comprehensive physicochemical characterizations, including XPS, FE-SEM, and TEM, confirmed the successful incorporation and uniform dispersion of ZnO nanoparticles within the carbon matrix. Electrochemical evaluations revealed that the ZnO-based cathode reduced overpotential during charge-discharge cycles and improved energy efficiency by approximately 6.3% over 40 cycles compared to pristine carbon paper (P50). <i>Ex situ</i> XRD and SEM analyses further validated the formation and decomposition of Li₂O₂ during cycling and suggested enhanced reaction uniformity owing to the catalytic role of ZnO. These findings demonstrate that <i>in situ</i>-grown ZnO offers a promising, low-cost strategy for improving the energy efficiency of Li-O₂ batteries.