Engineering topics

Jung, Hwa Young

Publications and source records attributed to Jung, Hwa Young.

4 records

DOE OSTI2018

Composition of a nickelate composite cathode for a fuel cell

In some embodiments, a solid oxide fuel cell comprising an anode, an electrolyte, cathode barrier layer, a nickelate composite cathode separated from the electrolyte by the cathode barrier layer, and a cathode current collector layer is provided. The nickelate composite cathode includes a nickelate compound and second oxide material, which may be an ion conductor. The composite may further comprise a third oxide material. The composite may have the general formula (Ln u M1 v M2 s ) n+1 (Ni 1-t N t ) n O 3n+1 -A 1-x B x O y --C. w D z Ce (1-w-z) O 2-δ , wherein A and B may be rare earth metals excluding ceria.

25 ENERGY STORAGE↗

DOE OSTI2018

Composition for fuel cell electrode

In some examples, a fuel cell comprising an anode; an electrolyte; cathode barrier layer; and a nickelate composite cathode separated from the electrolyte by the cathode barrier layer; and a cathode current collector layer. The nickelate composite cathode includes a nickelate compound and an ionic conductive material, and the nickelate compound comprises at least one of Pr.sub.2NiO.sub.4, Nd.sub.2NiO.sub.4, (Pr.sub.uNd.sub.v).sub.2NiO.sub.4, (Pr.sub.uNd.sub.v).sub.3Ni.sub.2O.sub.7, (Pr.sub.uNd.sub.v).sub.4Ni.sub.3O.sub.10, or (Pr.sub.uNd.sub.vM.sub.w).sub.2NiO.sub.4, where M is an alkaline earth metal doped on an A--site of Pr and Nd. The ionic conductive material comprises a first co-doped ceria with a general formula of (A.sub.xB.sub.y)Ce.sub.1-x-yO.sub.2, where A and B of the first co-doped ceria are rare earth metals. The cathode barrier layer comprises a second co-doped ceria with a general formula (A.sub.xB.sub.y)Ce.sub.1-x-yO.sub.2, where at least one of A or B of the second co-doped ceria is Pr or Nd.

30 DIRECT ENERGY CONVERSION↗

DOE OSTI2018

Composition for fuel cell electrode

In some examples, a fuel cell including an anode; electrolyte; and cathode separated from the anode by the electrolyte, wherein the cathode includes a Pr-nickelate based material with (Pr.sub.1-xA x ) n+1 (Ni 1-y B y ) n O 3 n+1+.delta. as a general formula, where n is 1 as an integer, A is an A-site dopant including of a metal of a group formed by one or more lanthanides, and B is a B-site dopant including of a metal of a group formed by one or more transition metals, wherein the A and B-site dopants are provided such that there is an increase in phase-stability and reduction in degradation of the Pr-nickelate based material, and A is at least one metal cation of lanthanides, La, Nd, Sm, or Gd, B is at least one metal cation of transition metals, Cu, Co, Mn, Zn, or Cr, where: 0<x<1, and 0<y.ltoreq.0.4.

25 ENERGY STORAGE↗

DOE OSTI2017

Activity and Stability of (Pr 1-x Nd x ) 2 NiO 4+δ as Cathodes for Oxide Fuel Cells: Part VI. The Role of Cu Dopant on the Structure and Electrochemical Properties

Phase instability in praseodymium nickelates is a major concern for the long-term operations of solid oxide fuel cells since it may lead to the performance degradation. In this work, praseodymium nickelates (ex. Pr 2 NiO 4+δ ) have been stabilized via substitution on both Pr- and Ni-sites. Systematic studies over a wide range of compositions were conducted via long-term thermal annealing studies (T ≤ 870°C) and electrochemical tests in full cells. Proposed (Pr 0.50 Nd 0.50 ) 2 Ni 1-y Cu y O 4+δ compositions (y = 0.05, 0.10, 0.20, and 0.30) showed the most promising results and serve as a comprehensive extension to our previous studies in this series of papers. A stable long-term performance was obtained for temperatures up to 790°C for 500 hours at 0.80 V with a minimal tradeoff between the activity (power density of 0.8–1.0 W cm -2 at 850°C) and performance stability. A preserved parent phase and suppressed performance degradation, when compared to Pr 2 NiO 4+δ , make newly developed electrodes attractive candidates for the state-of-the-art solid oxide fuel cell applications.

36 MATERIALS SCIENCE↗