Lattice Incorporation of Cu²⁺ into the BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3−δ Electrolyte on Boosting Its Sintering and Proton-Conducting Abilities for Reversible Solid Oxide Cells

Abstract

Lattice modification by incorporating heteroatoms could effectively and precisely tune their intrinsic properties to get improved sinterability and electrochemical performance. Here, by introducing Cu 2+ into the interstitial position of a ABO 3 -type perovskite, a 2 times higher protonic conductivity (1.9 × 10 −2 S cm −1 at 700 °C) and lowtemperature (1200 °C) sinterability were achieved for the BaCe 0.68 Zr 0.1 Y 0.1 Yb 0.1 Cu 0.02 O 3−δ (BCZYYC2) electrolyte, compared to the precursor electrolyte. Meanwhile, the modified BCZYYC2 also exhibits excellent chemical stability in high-temperature and high-humidity conditions, as well as good compatibility with the components of cell. When used as the electrolyte in reversible fuel cell (FC)/electrolysis cell (EC) operational modes, the reversible solid oxide cell with the BCZYYC2 electrolyte illustrates prominent FC (0.85 W cm −2 at 700 °C) and EC (−1.96 A cm −2 at 700 °C and 1.3 V) performances with high film−electrolyte conductivity (8.7 × 10 −3 S cm −1 at 700 °C). Additionally, an obvious increase in current density is observed during the short-term stability test, which has shown great promise for their practical application. KEYWORDS: BaCe 0.68 Zr 0.1 Y 0.1 Yb 0.1 Cu 0.02 O 3−δ , protonic conductivity, sinterability, stability, reversible solid oxide cells

A New Pd Doped Proton Conducting Perovskite Oxide with Multiple Functionalities for Efficient and Stable Power Generation from Ammonia at Reduced Temperatures

“…c) A comparison of the protonic conductivity in wet H 2 atmosphere (≈3% H 2 O) between the BZCYYbPd and various BaCeO 3 ‐based proton‐conducting electrolytes as reported in the literature. BaZr 0.1 Ce 0.7 Y 0.2 O 3− δ + 0.5 wt% NiO (BZCY7+NiO), [ 21 ] BaZr 0.1 Ce 0.68 Y 0.1 Yb 0.1 Cu 0.02 O 3− δ (BZCYYbCu), [ 22 ] BaCe 0.7 Zr 0.1 Y 0.1 Sm 0.1 O 3− δ (BCZYSm), [ 23 ] BaCe 0.7 Zr 0.1 Sm 0.2 O 3− δ (BCZSm), [ 23 ] BaCe 0.85 Er 0.15 O 3− δ (BCEr), [ 24 ] BaCe 0.45 Zr 0.4 Er 0.15 O 3− δ (BCZEr), [ 24 ] BaZr 0.1 Ce 0.7 Y 0.2 O 3− δ (BZCY7), [ 25 ] BaCe 0.5 Zr 0.3 Y 0.2 O 3− δ + 4 mol% ZnO (BCZY+ZnO). [ 26 ] d) Time dependence of total conductivity of BZCYYbPd electrolyte at 550 °C under different atmospheres.…”

“…A comparison of the protonic conductivity in wet H 2 atmosphere (≈3% H 2 O) between the BZCYYbPd and various BaCeO 3 ‐based proton‐conducting electrolytes as reported in the literature is given in Figure 4c. [ 21–26 ] Obviously, the BZCYYbPd electrolyte exhibits outstanding proton conductivity. Figure 4d shows the stability of the total conductivity of BZCYYbPd electrolyte at 550 °C under different atmospheres.…”

Degradation issues and stabilization strategies of protonic ceramic electrolysis cells for steam electrolysis

“…For example, introducing Cu 2+ into the interstitial position of BZCYYb1711 forms BaCe 0.68 Z r0.1 Y 0.1 Yb 0.1 Cu 0.02 O 3−δ (BCZYYC2), leading to excellent chemical stability at high-temperature and high-humidity conditions. 45 Furthermore, no degradation was found for the BCZYYC2 cell during a 60-h reversible operation and the R o remained almost constant (Figure 5E). Iron-doped BaZr 0.1 Ce 0.7 Y 0.2 O 3−δ (BZCY17) was stable during 25-hour operation with 100% H 2 O at 400°C, 35 whereas the pristine BZCY17 decomposed to F I G U R E 5 (A) Gibbs free energy of the reaction between BaZrO 3 or BaHfO 3 and CO 2 to form BaCO 3 and ZrO 2 or HfO 2 .…”

“…Reprinted with permission from Ref. 45 Copyright 2018 American Chemical Society. (F) Stability of PCEC with or without and La 2 Ce 2 O 7 (LCO) layer.…”

“…(E) The current density of the BCZYYC2 cell as a function of time tested at 700°C with a pulse voltage. Reprinted with permission from Ref 45 . Copyright 2018 American Chemical Society.…”