Solid oxide electrochemical cell with a unique chemical design: same cation composition of anode, cathode and electrolyte

• Published in: Journal of power sources Vol. 655; p. 237907
• Main Authors: Gordeev, E.V., Khodimchuk, A.V., Belyakov, S.A., Antonova, E.P., Osinkin, D.A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2025
• Subjects: DRT; LSF; LSGM; Oxygen pressure relaxation; SOFC; LSGM; LSF; DRT; SOFC; Oxygen pressure relaxation
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2025.237907

The subject of high-temperature solid oxide electrochemical devices is of significant interest in a wide range of scientific and technological domains. A lot of scenarios for the use of such devices are being considered: power generation, gas conversion, procurement and monitoring of gases, etc. The present study proposes a chemical design concept for an electrochemical cell, in which the anode, cathode, and electrolyte have a similar and even identical ionic composition. This was achieved through the use of a highly conductive (La,Sr) (Ga,Mg)O3-δ electrolyte, doped with Fe, in conjunction with symmetrical electrodes based on (La,Sr)FeO3-δ, doped with Ga and Mg. The results showed that the closer the ionic composition, the less probability of chemical interaction between the materials. Using the method of oxygen pressure relaxation, it is shown that the substitution of iron in (La,Sr)FeO3-δ by Ga and Mg leads to an increase of oxygen exchange with the gas phase. The modified La0.6Sr0.4Fe0.85Ga0.1Mg0.05O3-δ electrode in contact with the (La0.8Sr0.2)0.98Ga0.7Fe0.1Mg0.2O3-δ electrolyte demonstrated a polarization resistance of about 0.06 Ω cm2 at 800 °C. The power of a symmetrical fuel cell with such electrodes was about 160 mW cm−2, and this is limited by the hydrogen oxidation reaction rate. [Display omitted] •A unique approach to the chemical design of electrochemical cell is proposed.•The cell with identical cationic composition of functional layers was investigated.•The reasons limiting the efficiency of such a cell have been established.•Proposed ways to improve efficiency of a cell.