Cycling tests of a reversible BaCe0.8Zr0.1Y0.1O3−δ electrolyte-based protonic ceramic cell with SmBa0.5Sr0.5Co1.5Fe0.5O5+δ oxygen electrode


Cells based on proton-conducting ceramics (PCC) working at intermediate temperatures have intrinsic properties that suggest promising potential applications. Currently, almost all the literature in the field of PCC has focused on hydrogen conversion (Protonic Ceramic Fuel Cell PCFC) and/or hydrogen production (Protonic Ceramic Electrolysis Cell PCEC). Very few studies have inspected the reversibility of these systems (RePCC) in order to understand their potential coupling to intermittent renewable energies. Despite the promising results achieved, the development of these technologies remains very challenging.

The work presented here illustrates the fabrication and the characterization of a 32 mm–diameter hydrogen-electrode-supported cell. A double perovskite with general formula AA’BB’O5+δ is used as air electrode material (SmBa0.5Sr0.5Co1.5Fe0.5O5+δ, SmBSCF) exhibiting very good stability under water vapor- and carbon dioxide-containing atmosphere.

The maximal power density of the Ni–BaCe0.8 Zr0.1Y0.1O3-δ (Ni-BCZY81)/BCZY81/SmBSCF cell corresponds to 0.58 W cm−2 at 600 °C in fuel cell mode and a current density of j = 0.8 A cm−2 is measured at 1.3 V and 600 °C in electrolysis mode. The results were collected over a total working time of 280 h. The cell was stressed with several complete shutdowns and restarting protocols exhibiting an overall remarkable reversibility and durability.

Link to source: https://www.sciencedirect.com/science/article/pii/S0378775323011357

A2.2. Cell manufacturing

The electrolyte was deposited by Wet Powder Spraying (WPS), as described in previous works [19]. For this purpose, the BCZY81 and LiZnO sintering aid (3 M %) powders were dispersed (3 wt% of BCZY81) into isopropanol (99.5 % purity, Sigma-Aldrich) under ultrasonic irradiation to form a stable suspension. No further additives were used, such as binders, plasticizers, or dispersants. The suspension was sprayed onto a fresh substrate cut in a round shape (ø 40 mm), using a Spray Coater ND-SP from Nadetech Innovations®. Air was used as the carrier gas at a working pressure of 1.3 atm. The spray process was carried out at a substrate temperature of 55 °C with the help of a hot plate. 13 40-mm square layers were sprayed with a suspension flow rate of 50 ml h−1 with a nozzle velocity of 700 mm min−1 resulting in a deposition of 0.8 ml cm−2. The half-cell was then sintered in air at 1350 °C for 6 h using a ramp of 1 °C/min, attaining a final diameter of 32 mm with a final fuel electrode and electrolyte thicknesses of approximately around 500 μm and 5 μm.

Keywords: Protonic ceramic fuel cell; Protonic ceramic electrolysis cell; Reversibility; BCZY81; SmBSCF