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

Abstract

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, LaCo0.6Ni0.4O3−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 CO2 reduction reaction (CO2RR). 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.% Y2O3 stabilized ZrO2) 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.