Enhanced Performance of Protonic Solid Oxide Steam Electrolysis Cell of Zr-Rich Side BaZr0.6Ce0.2Y0.2O3-δ Electrolyte with an Anode Functional Layer

Hajime Toriumi; SeongWoo Jeong; Sho Kitano; Hiroki Habazaki; Yoshitaka Aoki

doi:10.1021/acsomega.2c00569

Enhanced Performance of Protonic Solid Oxide Steam Electrolysis Cell of Zr-Rich Side BaZr_0.6Ce_0.2Y_0.2O_3-δ Electrolyte with an Anode Functional Layer

ACS Omega. 2022 Mar 9;7(11):9944-9950. doi: 10.1021/acsomega.2c00569. eCollection 2022 Mar 22.

Authors

Hajime Toriumi¹, SeongWoo Jeong¹, Sho Kitano², Hiroki Habazaki², Yoshitaka Aoki²

Affiliations

¹ Graduate School of Chemical Sciences and Engineering, Hokkaido University, N13W8 Kita-ku, Sapporo 060-8628, Japan.
² Faculty of Engineering, Hokkaido University, N13W8 Kita-ku, Sapporo 060-8626, Japan.

Abstract

Proton-conducting solid oxide electrolysis cells (H-SOEC) containing a 15-μm-thick BaZr_0.6Ce_0.2Y_0.2O_3-δ (BZCY622) electrolyte thin film, porous cathode cermet support, and La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ anodes were fabricated using a reactive cofiring process at approximately 1400 °C. Steam electrolysis was conducted by supplying wet air to the anode at a water partial pressure of 20 kPa. The performance was evaluated using electrochemical measurements and gas chromatography. At 600 °C, the cells generated an electrolysis current of 0.47 A cm^-2 at a 1.3 V bias while the Faradaic efficiency reached 56% using 400 mA cm^-2. The electrolysis performance was efficiently improved by introducing a 40-nm-thick La_0.5Sr_0.5CoO_3-δ (LSC) nanolayer as an anode functional layer (AFL). The cells with LSC AFL produced an electrolysis current of 0.87 A cm^-2 at a 1.3 V bias at 600 °C, and the Faradaic efficiency reached 65% under 400 mA cm^-2. Impedance analysis showed that the introduction of the AFL decreased the ohmic resistances and improved interfacial proton transfer across the anode/electrolyte interface and polarization resistances related to the anode reaction. These results demonstrate opportunities for future research on AFL to improve the performance of H-SOECs with Zr-rich BaZr _x Ce_1-x-y Y _y O_3-δ electrolytes.