Rational Design of Two-Layer Fe-Doped PrBa_0.8Ca_0.2Co₂O_6−δ Double Perovskite Oxides for High-Performance Fuel Cell Cathodes

Abstract

A solid oxide fuel cell (SOFC) offers an attractive route to convert chemical energy into electrical energy; however, its commercial application is often limited by the large mismatch in thermal expansion coefficients (TECs) between the cathode and electrolyte and the insufficient activity of cathodes. Fe-doped PrBa 0.8 Ca 0.2 Co 2 O 6−δ (PBCC) are promising cathode materials due to their high conductivity and excellent oxygen-reduction activity, in which Fe doping in PBCC can decrease the TEC to achieve better compatibility with the electrolyte, but excessive Fe will inhibit the oxygen kinetics. Here, we construct a two-layer PBCC cathode (TLC), which consists of a high Fe content layer with good thermal compatibility to electrolytes and a low Fe content layer with high ionic and electronic conductivity. Compared to homogeneous PBCC electrodes, the cell with TLC has a lower activation energy and a higher peak power density (1259.3 mW cm −2 at 700 °C). Meanwhile, it exhibits admirable stability up to 200 h in constant potential mode (0.8 V), and importantly, no discernible degradation is observed in further stability tests in the constant current mode (444 mA cm −2 ) for 200 h. The results reveal that the TLC based on double perovskite Fe-doping isostructural oxide is a promising candidate electrode for SOFC.

A mini review of the recent progress of electrode materials for low-temperature solid oxide fuel cells

“…2 Recently, studies have been focused on lowering the operating temperature of SOFCs to a low-temperature range (450-650 1C) to further broaden the application scope and alternative material range, as well as decrease the cost, shorten start-up time, and enhance lifetime. 3,4 However, lowering the operating temperature of SOFCs is challenged by both the ionic (O 2À /H + ) transport in the solid electrolyte and electrode reactions, which are thermally activated processes. 5 Therefore, it is necessary and urgent to optimize the kinetic reaction conditions occurring at the electrolyte, electrodes, and their interfaces.…”

“…The same impact has been proven by many follow-up studies. 3,[104][105][106][107] This strategy not only endows the electrode with excellent catalytic performance but also avoids the mismatch TEC of Co-based materials.…”

Rational Design of NiO-8YSZ Screen-Printing Slurry for High-Performance Large-Area Solid Oxide Cells

“…Solid oxide cells (SOCs) consist of solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs). They are regarded as one of the most promising energy conversion and storage devices for sustainable and green energy development. − SOCs are capable of both energy storage and regeneration in an intermediate temperature range of 600–800 °C with remarkably high efficiencies and low greenhouse emissions. , SOC applications that electrochemically convert the chemical energy of liquid or gaseous fuels into electricity have been dedicated to carbon-neutral power generation and supply as an alternative to fossil-derived energy. Therefore, SOC technology has the potential to be a key aspect in achieving carbon-neutrality. − …”

The Journal of Physical Chemistry C Virtual Special Issue on “Energy and Catalysis in China”

“…Moreover, the influence of the microstructures and transport properties of ionomer films on the performance of Pt single atom catalysts (SACs) in polymer electrolyte membrane fuel cells (PEMFCs) has been reported . The development of electrode materials for lithium-ion batteries is included in this VSI: lithium-iron-phosphate-coated LiNi x Co y Mn 1– x – y O 2 (NCM) and porous Co 3 O 4 nanoparticles assembled nanostructures for lithium-ion batteries, and N,S-codoped three-dimensional (3D) network carbon materials supported RuO 2 for Li–O 2 batteries, while Fe-doped PrBa 0.8 Ca 0.2 Co 2 O 6−δ double perovskite oxide is reported as an efficient cathode material for solid oxide fuel cells . The understanding of reactive oxygen species in aprotic lithium–oxygen batteries is reviewed .…”

“…9 The development of electrode materials for lithium-ion batteries is included in this VSI: lithium-iron-phosphatecoated LiNi x Co y Mn 1−x−y O 2 (NCM) 10 and porous Co 3 O 4 nanoparticles assembled nanostructures for lithium-ion batteries, 11 and N,S-codoped three-dimensional (3D) network carbon materials supported RuO 2 for Li−O 2 batteries, 12 while Fe-doped PrBa 0.8 Ca 0.2 Co 2 O 6−δ double perovskite oxide is reported as an efficient cathode material for solid oxide fuel cells. 13 The understanding of reactive oxygen species in aprotic lithium−oxygen batteries is reviewed. 14 There are also several papers concerning other important/emerging electrocatalytic reactions and energy processes: the oxygen evolution reaction (OER) on a carbon-nanotube-supported NiIr x nanoalloy, 15 NiO/CuO nanosheet, 16 or Ni 3 S 2 /Fe(OH) 2 , 17 the hydrogen evolution reaction (HER) on WNi 4 @W−WO 2 , 18 CO 2 reduction on a 3D porous Zn catalyst, 19 oxygen reduction to hydrogen peroxide on a Nd-doped Bi 4 Ti 3 O 12 nanosheet, 20 the reduction of N 2 to ammonia on a Au/SiO 2 /Si photocathode, 21 the selective oxidation of methane to ethanol on Rh/ZnO nanosheets, 22 the triiodine reduction reaction on zeoliticimidazolate-framework-derived Co−N 3 SACs, 23 the electrohydrogenation of cinnamate esters on graphite felt electrode, 24 and electricity generation via the hydrovoltaic effect.…”