Evaluation of thin film fuel cells with Zr-rich BaZr_xCe_0.8−xY_0.2O_3−δ electrolytes (x ≥ 0.4) fabricated by a single-step reactive sintering method

Abstract

This paper reports on the survey of power generation characteristics of anode-supported thin film fuel cells with Zr-rich side BaZrxCe0.8–xY0.2O3–δ (x = 0.4, 0.6, 0.7, and 0.8) proton conducting electrolytes.

Metal/Oxide Heterojunction Boosts Fuel Cell Cathode Reaction at Low Temperatures

“…The σ of Sc20‐cell shows a linear Arrhenius relationship with the related activation energy ( E a ) of 0.27 eV, which agrees with the previously reported E a of PCFC thin films. [ 28,29 ] The σ of Sc50‐cell is apparently greater than that of the Sc20‐cell at all temperatures, with a value of 10 −3 S cm −1 at 400 °C, deviating downward above 400 °C, which can be attributed to the decline of protonic carriers because of dehydration at elevated temperatures. [ 30 ]…”

A Reversible Protonic Ceramic Cell with Symmetrically Designed Pr2NiO4+δ-Based Electrodes: Fabrication and Electrochemical Features

“…Since this cell maintains gas-impenetrability (measured at room temperature under 10 −3 atm/1 atm of total gas pressures gradient), the most likely reason for the observed differences is non-ionic conduction of the BCZD electrolyte. Indeed, both BaCeO 3 - and BaZrO 3 -based materials demonstrate meaningful electron conductivity in oxidizing conditions at high temperatures [36,37]. Regarding the BCZD electrolyte, its ionic transference numbers (t i ) estimated as a ratio of its ionic conductivity measured in wet H 2 to the total conductivity measured in wet air only reached 0.78, 0.62, 0.50 and 0.44 at 600, 650, 700 and 750 °C [38].…”

“…For the present case, the average ionic conductivity of BCZD reaches 4.7 and 4.9 mS cm −1 at 600 and 700 °C under condition 1 and 4.9 and 5.4 mS cm −1 , respectively, under condition 2. These belong to a range of the highest values reached for proton-conducting electrolytes (Table 2, [37,52,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79]), which agrees with the independently measured comparison of ionic conductivities of Y- and Dy-doped Ba(Ce,Zr)O 3 [80]. The abovementioned results allow the following important conclusions to be formulated:The BCZD electrolyte forms the basis for the design of novel electrochemical cells with improved output parameters due to its higher ionic conductivity compared with those for the most-studied Y-containing cerate-zirconates;Despite the negative electrochemical response of the electrodes to gas humidification, the average ionic transference and ionic conductivity values take the opposite direction, resulting in improved PCC efficiency.…”

A Reversible Protonic Ceramic Cell with Symmetrically Designed Pr₂NiO_4+δ-Based Electrodes: Fabrication and Electrochemical Features

“…The operability of the reversible PCC is shown in Figure 4a. BaZrO3-based materials demonstrate meaningful electron conductivity in oxidizing conditions at high temperatures [36,37]. Regarding the BCZD electrolyte, its ionic transference numbers (ti) estimated as a ratio of its ionic conductivity measured in wet H2 to the total conductivity measured in wet air only reached 0.78, 0.62, 0.50 and 0.44 at 600, 650, 700 and 750 °C [38].…”