Multi-functionalities enabled fivefold applications of LaCo0.6Ni0.4O3−δ in intermediate temperature symmetrical solid oxide fuel/electrolysis cells.

A solid oxide cell (SOC) integrating solid oxide fuel cell (SOFC) and solid oxide electrolysis cell (SOEC) usually utilizes two different materials as the anode and cathode prepared by the costly multi-elements co-doping process. In this work, LaCo 0.6 Ni 0.4 O 3−δ (LCN) is employed as the contact material and the electrode for the symmetrical SOC and exhibits good catalytic activities towards the four typical reactions, i.e., oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR), oxygen evolution reaction (OER), and CO 2 reduction reaction (CO 2 RR). The LCN-GDC electrode has the low activation energies of 1.18 and 0.55 eV as the cathode and anode of SOFC, respectively. High peak power densities (PPDs) of 1.896 and 0.562 W cm⁻² are obtained at 800 °C for the Ni-YSZ (8 mol.% Y 2 O 3 stabilized ZrO 2) anode-supported and YSZ (200 μm)-supported symmetrical SOFCs, respectively. An electrolysis current density (ECD) of 2.316 A cm⁻² is obtained at 800 °C and 2.0 V and a robust operation for over 120 h with a degradation rate of about 0.5 mV h⁻¹ is achieved with LCN as the current collector in air side at 750 °C for the symmetrical SOECs. Such a multi-functional material shows attractive competitiveness and successfully achieves fivefold applications in SOCs. The protocol described herein affords a new vision towards material development basing on the consideration of enhancing the chemical compatibility and lowering the cost of the whole SOC but not just one electrode. We report the successful fivefold applications of the multi-functional LaCo 0.6 Ni 0.4 O 3-δ in solid oxide cells for the multipurpose scenarios basing on the perceptively and integrally consideration of enhancing the chemical compatibility and lowering the fabrication cost of the whole integrated solid oxide device but not just one electrode. Image 1 • LCN is employed as electrodes to enhance the compatibility and lower the cost of the whole SOC but not just one component. • The fivefold applications of LCN benefit from its high conductivity and phase diversity against atmospheres. • LCN-GDC has small activation energies of 1.18 and 0.55 eV as the cathode and anode of SOFC, respectively. • PPDs of 1.896 and 0.562 W cm⁻² are obtained at 800 °C for the anode-supported and symmetrical SOFCs, respectively. • An ECD of 2.316 A cm^-2 at 800 °C and 2.0 V and good stability of over 120 h are obtained for the symmetrical SOECs. [ABSTRACT FROM AUTHOR]