The Ln2NiO4+δ-based layered phases have attracted much attention as components for high-performance protonic ceramic fuel cells (PCFCs) and electrolysis cells (PCECs) enabling energy conversion with good efficiency and low pollution.The present paper aims at rationally engineering the Cu-doped Pr2NiO4+δ materials and analysing their electrode behaviour for reversible protonic ceramic cells operating in both PCFC and PCEC modes.Complex oxides of Pr2Ni1-xCuxO4+δ (x =0,0.1,0.2 and 0.3) were synthesised using the citrate-nitrate method.The obtained materials were characterised considering their crystalline structures,as well as thermal,thermomechanical and electrotransport properties.A special interest was focused on the quality of an electrode/electrolyte interface governing the electrochemical performance of the cells fabricated.It is shown that a copper doping of x =0.2 has a positive impact on the ther-momechanical compatibility of the Ba(Ce1Zr)O3-based electrolytes,providing a better adhesion to these electrolytes at low-temperature sintering and resulting in a decrease of the polarisation resistance of the air electrodes.A reversible protonic ceramic cell demonstrates a power density of ～340 mW cm-2 and a hydrogen output flux of ～3.8 ml cm-2 min-1 at 750 ℃.The presented results propose modernised alkaline-earth-element-free and cobalt-free electrodes that can be successfully used in the electrochemi-cal cells based on the-state-of-the-art proton-conducting electrolytes.