Incorporation and conduction of proton in Sr-doped LaMO3 (M=Al, Sc, In, Yb, Y)

The performance of protonic ceramic fuel cells (PCFCs) using thin film BaCe 0.6 Zr 0.2 Y 0.2 O 3-δ (BCZY622) electrolyte has been studied. The reference cell with the La 0.8 Sr 0.2 MnO 3-δ cathode and Ni anode showed poor performance and short-term degradation. The overpotential of the anode and ohmic loss were the major factors for degradation, and a solid solution of Ni in the BCZY electrolyte has been observed. The electrical conductivity and the proton concentration of BCZY and BCZY622 doped with 5wt% NiO were measured by an impedance analysis and thermogravimetric analysis. The electrical conductivity and the proton concentration of BCZY622 decreased by introducing NiO. To avoid short-term degradation, the cell construction, manufacturing process, and cathode materials were improved. As a result, a carefully designed PCFC with thin film BCZY622, Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ cathode and Ni/BCZY622 cermet anode showed good power density of 200-300mW/cm 2 in the wide temperature range of 873 -1073K, and had stable power generation.

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“…In a previous study [13,[15][16][17][18], we suggested that the partial oxygen vacancies cannot take part in the hydration. •…”

Section: Ni Addition Effect On the Conductivity And Proton Concentrationmentioning

confidence: 99%

Improvement of Protonic Ceramic Fuel Cells with Thin Film BCZY Electrolyte

et al. 2015

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“…Since the reaction in Equation is exothermic, the proton concentration decreased with the increasing temperature shown in Figure e–h and the following equation

K_{normalw} = \exp (\frac{normalΔ S °}{R}) \exp (- \frac{normalΔ H °}{R T}) = \frac{{[{OH}_{normalO}^{•}]}^{2}}{[{normalV}_{normalO}^{• •}] [{normalO}_{normalO}^{x}] {pH}_{2} O}

where Δ H ° and Δ S ° are the standard molar enthalpy and entropy, respectively. Some proton‐conducting oxides with these parameters after hydration are listed in Table 1 …”

Section: Functional Materials Of Proton‐conducting Socsmentioning

confidence: 99%

Gas Humidification Impact on the Properties and Performance of Perovskite‐Type Functional Materials in Proton‐Conducting Solid Oxide Cells

Wang

Medvedev

Shao

2018

Adv Funct Materials

103

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Fuel cells and electrolysis cells as important types of energy conversiondevices can be divided into groups based on the electrolyte material. However, solid oxide cells (SOCs) based on conventional oxygen-ion conductors are limited by several issues, such as high operating temperature, the difficulty of hydrogen purification from water, and inferior stability. To avoid these problems, proton-conducting oxides are proposed as electrolytes for SOCs in electrolysis and fuel cell modes. Since water vapor partial pressure (pH 2 O) is one of the main parameters determining the proton concentration in proton-conducting oxides (characteristics of which can be either improved or deteriorated), the pH 2 O control is extremely important for the optimization of the devices' performance and stability. This review provides an overview of the research progresses made for proton-conducting SOCs, especially for the impact of gas humidification on the operability and performance. Fundamental understanding of the main processes in proton-conducting SOCs and design principles for the key components are summarized and discussed. The trends, challenges, and future directions that exist in this dynamic field are also pointed out. This review will inspire interest from various disciplines and provide some useful guidelines for future development of proton-conductor-based energy storage and conversion systems.

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“…However, the maximum proton concentration could not reach the dopant level and was dependent on the mixture ratio of the cation on the B-site. In our previous study, lanthanum-based perovskite oxides have a characteristic proton concentration [6,9]. Kreuer reported that the low saturation limits are explained by the decay of two oxygen sites with different affinities toward the hydration reaction [10].…”

Section: Resultsmentioning

confidence: 98%

“…We consider the hydration energy based on the assumption that the partial oxygen vacancies cannot take part in the hydration in the same manner as described in a previous study [5,6,9]. In the present system, the electrical neutrality condition is expressed as follows: denote the oxygen vacancy involved in the hydration and the immobile oxygen ion which do not take part in hydration, respectively.…”

Section: ••mentioning

confidence: 98%