From half-cells to full-cells: across-scale comparative evaluation of lanthanum-based perovskites as high-performance anode materials for the oxygen evolution reaction

Abstract

The widespread reliance on evaluating electrocatalysts in electrochemical half-cells presents limitations that hinder a faster transition from academia to industry and can lead to premature exclusion of promising materials. To address these challenges, it is crucial to implement materials testing in application-relevant setups such as zero-gap full-cells. This transition can be achieved through implementing coherent workflows combining rapid evaluation of as-synthesized materials, electrode evaluation at different scales, and post-mortem analysis. This work presents a comparative study of three spray-flame synthesized lanthanum-based perovskite materials (LaMnO₃, LaFeO₃, and LaCoO₃) for the oxygen evolution reaction under alkaline conditions, highlighting different behavior across scales. The research demonstrates how the interplay of materials properties and electrode engineering affects performance under mild and harsh electrochemical conditions. At every step, these perovskites challenge existing literature through unforeseen behavior. Under application-relevant conditions, the results suggest that LaFeO₃ (2.09 V) and LaMnO₃ (2.16 V), with comparable performance, could potentially replace LaCoO₃ (2.07 V). Furthermore, advanced post-mortem techniques provide deeper insight into catalytic activity and structural changes, which cannot be fully explained without preliminary electrochemical half-cell testing. By linking fundamental studies to application-relevant testing, this research provides knowledge and methods for accelerated material and electrode development.