Electrochemical Charge–Discharge Behavior of a Binder‐Free 3D ‐Printed LCNO ‐Derived Multiphase La–Cu–Ni–O Ceramic Electrode

Abstract

ABSTRACT In this study, the electrochemical charge–discharge behavior of a binder‐free, self‐supporting, porous three‐dimensional (3D) LCNO‐derived multiphase La–Cu–Ni–O ceramic electrode (LCNO‐MP) fabricated from a nominal La 2 CuNiO 6 precursor powder (LCNO) was investigated. The sintered electrode derived from this LCNO precursor powder is referred to as the LCNO‐derived multiphase La–Cu–Ni–O ceramic electrode, abbreviated as LCNO‐MP electrode. Structural and morphological analyses (XRD, FE‐SEM, FT‐IR, and BET) confirmed that sintering produced an interconnected porous electrode architecture while preserving a dominant LCNO‐related La–Cu–Ni–O mixed oxide phase accompanied by secondary lanthanum nickel oxide, lanthanum copper oxide, and metallic Ni phases. The electrochemical response of the LCNO‐MP electrode was evaluated in 1.0 M KOH electrolyte using electrochemical impedance spectroscopy (EIS), cathodic polarization, cyclic voltammetry (CV), and galvanostatic charge–discharge (GCD) analyses. EIS results indicated measurable but kinetically limited interfacial charge‐transfer behavior within the standalone porous ceramic electrode. CV analyses revealed faradaic redox features; however, the unusually low b value of 0.243 indicates a highly non‐ideal electrochemical response influenced by polarization, resistive limitations, possible side reactions, and peak‐selection uncertainty rather than a clear diffusion‐controlled hydrogen insertion/extraction mechanism. GCD measurements showed measurable Faradaic charge/discharge behavior; however, the large difference between charge and discharge capacities and the recoverable discharge capacity below 0.20 mAh g −1 indicate poor reversibility, likely due to parasitic hydrogen evolution, irreversible redox processes, polarization losses, and/or other side reactions. Overall, the 22‐cycle GCD test revealed a time‐dependent, non‐stabilized, and poorly reversible electrochemical response.