New Strategy for Boosting Cathodic Performance of Protonic Ceramic Fuel Cells Through Incorporating a Superior Hydronation Second Phase

Abstract

For protonic ceramic fuel cells, it is key to develop material with high intrinsic activity for oxygen activation and bulk proton conductivity enabling water formation at entire electrode surface. However, a higher water content which benefitting for the increasing proton conductivity will not only dilute the oxygen in the gas, but also suppress the O2 adsorption on the electrode surface. Herein, a new electrode design concept is proposed, that may overcome this dilemma. By introducing a second phase with high‐hydrating capability into a conventional cobalt‐free perovskite to form a unique nanocomposite electrode, high proton conductivity/concentration can be reached at low water content in atmosphere. In addition, the hydronation creates additional fast proton transport channel along the two‐phase interface. As a result, high protonic conductivity is reached, leading to a new breakthrough in performance for proton ceramic fuel cells and electrolysis cells devices among available air electrodes.

First observation of electrode-correlated protonic conductivity of perovskite-type electrolytes and way towards optimization

“…For example, PBSCF, while containing a large amount of oxygen in its lattice, demonstrated poor hydration capability, while H 2 O-TPD-MS provides an efficient way of determining the hydration capability of an electrode material. To further improve the performance of PCFCs, a material with superhydration capability can be introduced into the air electrode as a second phase, 45 which will increase the water content in the electrolyte, thus improving both the proton conductivity of the electrode and electrolyte, leading to increased cell performance. Considering the competing adsorption of water and O 2 over the electrode surface, while sufficient hydration of the electrode is important to introduce proton conductivity into the electrode and maximize the protonic conductivity of the electrolyte, the humidity of the surrounding air electrode atmosphere should be well managed, which can be realized through controlling the air flow rate.…”

Electronic engineering and oxygen vacancy modification of La0.6Sr0.4FeO3−δ perovskite oxide by low-electronegativity sodium substitution for efficient CO2/CO fueled reversible solid oxide cells

“…Meanwhile, some researchers have proposed that it played positive roles in the ORR at the fuel electrode side for the SOFCs, proton uptake in protonic ceramic fuel cells, and the OER in ruthenium perovskite electrocatalysts for acidic media because of its low valence and low-electronegativity as well as its hydratability. 51,53,54 Combining those positive roles, the potential of using Na-doped perovskite fuel electrode materials should be explored since the core of the CO 2 reduction reaction (CO 2 -RR) is also the oxygen exchange process on the typical three-phase boundaries.…”

Enhancing the CO2 Adsorption of the Cobalt-Free Layered Perovskite Cathode for Solid-Oxide Electrolysis Cells Gains Excellent Stability under High Voltages via Oxygen-Defect Adjustment

“…These cells have several advantages, including a simple structure, environmentally friendly attributes, and high electrolysis efficiency. − With regard to clean energy development, overcoming the energy crisis, and achieving carbon neutrality objectives, the direct electrolysis of CO 2 using SOECs plays a crucial role. The CO 2 reduction process at the cathode is the main rate-limiting step when it is used for direct electrolysis of CO 2 . , Therefore, it is imperative to develop cathode materials with outstanding catalytic activity, high stability, and low manufacturing cost for the large-scale implementation of SOECs. − …”