Electrochemical performance of La2NiO4+δ-Ce0.55La0.45O2−δ as a promising bifunctional oxygen electrode for reversible solid oxide cells

In this work, La2NiO4+δ-xCe0.55La0.45O2−δ (denoted as LNO-xLDC) with various LDC contents (x = 0, 10, 20, 30, and 40 wt%) were prepared and evaluated as bifunctional oxygen electrodes for reversible solid oxide cells (RSOCs). Compared with the pure LNO, the optimum composition of LNO-30LDC exhibited the lowest polarization resistance (Rp) of 0.53 and 0.12 Ω·cm2 in air at 650 and 750 °C, respectively. The enhanced electrochemical performance of LNO-30LDC oxygen electrode was mainly attributed to the extended triple phase boundary and more oxygen ionic transfer channels. The hydrogen electrode supported single cell with LNO-30LDC oxygen electrode displayed peak power densities of 276, 401, and 521 mW·cm−2 at 700, 750, and 800 °C, respectively. Moreover, the electrolysis current density of the single cell demonstrated 526.39 mA·cm−2 under 1.5 V at 800 °C, and the corresponding hydrogen production rate was 220.03 mL·cm−2·h−1. The encouraging results indicated that LNO-30LDC was a promising bifunctional oxygen electrode material for RSOCs.