An Active Oxygen Electrode for Proton‐Conducting Solid Oxide Electrolysis Cells with High Faradaic Efficiency

In this work, a highly active oxygen electrode material, BCZZ is designed and synthesized for P-SOECs. A high electrolysis current density and FE is achieved for P-SOECs with BCZZ electrode. Moreover, the effect of both external and intrinsic properties on FE is systematically studied for the first time.

Abstract

Addressing the challenges posed by inferior electrochemical performance at low temperatures and the uncertain Faradaic efficiency (FE) represents a pivotal undertaking in the development of high performance and efficient proton-conducting solid oxide electrolysis cells (P-SOECs). In this work, a novel oxygen electrode material BaCo_0.8Zr_0.1Zn_0.1O_3-δ (BCZZ) is first designed and synthesized. At 600 °C, P-SOECs with BCZZ oxygen electrode achieve an electrolysis current density of 1.98 A cm⁻² with an ≈90% FE at 1.3 V. Utilizing 1-inch P-SOECs as a reliable platform, the effect of extrinsic operating conditions (i.e., steam concentration, voltage, current density, and temperature) and intrinsic properties of P-SOECs (i.e., electrolyte material and electrolyte thickness) on FE are further systemically investigated, both experimentally and theoretically.