Suitability of Pr2–xCaxNiO4+δ as cathode materials for electrochemical devices based on oxygen ion and proton conducting solid state electrolytes

Oxygen transport in Pr nickelates: Elucidation of atomic-scale features

“…Pr 2 NiO 4+δ oxide with a layered Ruddlesden-Popper (R-P) structure is a promising material for SOFC cathodes [1][2][3][4][5][6][7][8], electrodes for electrolysers and reversible cells [9,10] and oxygen separation membranes [11][12][13][14] due to a high oxygen mobility provided by the cooperative mechanism of oxygen migration involving both interstitial oxygen species and apical oxygen of the NiO 6 octahedra, as well as intermediate values of thermal expansion coefficients (TECs) and stability to carbonization [3,5,11,[15][16][17][18][19][20]. Doping is usually applied to diminish Pr 2 NiO 4+δ phase instability in the temperature range of 850-1000°C [21].…”

“…Doping is usually applied to diminish Pr 2 NiO 4+δ phase instability in the temperature range of 850-1000°C [21]. Particularly, it was found that doping by Ca improves thermodynamic stability of Pr 2 NiO 4+δ at these temperatures, increases electronic conductivity, decreases the thermal expansion coefficient value and chemical interaction with a number of solid state electrolytes [6,20,22]. However, Ca-doping decreases oxygen mobility due to decreasing the oxygen excess and appearing of 1-2 additional slow diffusion channels at x ≥ 0.4, probably, due to hampering the cooperative mechanism of oxygen migration [19,20,23,24].…”

A Reversible Protonic Ceramic Cell with Symmetrically Designed Pr2NiO4+δ-Based Electrodes: Fabrication and Electrochemical Features

“…In contrast to the previously mentioned simple or double perovskite, a layered structure of praseodymium nickelate is substituted under reducing atmospheres to complete Ni reduction and formation of a Ni–Pr 2 O 3 cermet (Figure 1) with good electrocatalytic properties [18,19]. Along with the symmetrical electrode application and reversible operation mode, the close thermal expansion coefficients (TECs) of Pr 2 NiO 4+δ - and Ba(Ce,Zr)O 3 -based materials [20,21] allow a one-step sintering procedure to be used. According to the literature analysis, a single temperature processing step is a highly attractive approach for reducing the fabrication costs; in particular, this strategy has recently been adopted for the production of PCCs [8,22,23].…”

A Reversible Protonic Ceramic Cell with Symmetrically Designed Pr₂NiO_4+δ-Based Electrodes: Fabrication and Electrochemical Features

“…In contrast to the previously mentioned simple or double perovskite, a layered structure of praseodymium nickelate is substituted under reducing atmospheres to complete Ni reduction and formation of a Ni-Pr2O3 cermet ( Figure 1) with good electrocatalytic properties [18,19]. Along with the symmetrical electrode application and reversible operation mode, the close thermal expansion coefficients (TECs) of Pr2NiO4+δ-and Ba(Ce,Zr)O3-based materials [20,21] allows a one-step sintering procedure to be used. According to the literature analysis, a single temperature processing step is a highly attractive approach for reducing the fabrication costs; in particular, this strategy has recently been adopted for the production of PCCs [8,22,23].…”