Simultaneous Operando Characterization of Crystallographic and Electrochemical Properties of Ni-Ce_0.9Gd_0.1O_2-δSolid Oxide Fuel Cell Anode

Abstract

A novel dual chamber (DC) measurement cell has been implemented for simultaneous monitoring of crystallographic and electrochemical (EC) properties of Ni-Ce 0.9 Gd 0.1 O 2−δ (Ni-GDC) solid oxide fuel cell (SOFC) anode at different fuel cell polarizations. The influence of system parameters (temperature, oxygen partial pressure in anode compartment and oxide ion flux through the electrolyte membrane from the cathode to the anode) on the crystallographic structure of GDC and redox performance of Ni has been studied. The oxide ion flux through the membrane from cathode to anode leads to increase of oxygen partial pressure in anode layers close to electrolyte. Increase of oxygen partial pressure leads to decrease of unit cell volume of the GDC lattice. The observed average change of GDC lattice parameter was 0.0147 Å V −1 at 800 • C. The oxidation of Ni caused by oxide ion flux at high fuel cell loads has been detected electrochemically but not from XRD results.

An Anisotropic Microstructure Evolution in a Solid Oxide Fuel Cell Anode

“…This technique was widely used to improve numerical modeling [12][13][14][15][16][17] and more recently to understand the degradation mechanisms of a solid oxide fuel cell anode [18][19][20][21][22][23][24]. That became a valuable endorsement to the recent crystallographic studies [25,26].…”

Study of Electrochemical and Crystallographic Changes During Initial Stabilization of La0.75Sr0.25Cr0.5Mn0.3Ni0.2O3−δ Reversible Solid Oxide Cell Electrode

“…In our previous study where Ni‐GDC was used as the fuel electrode 41, we also detected the increase in the a ScCeSZ during first 1,000 min of cell operation at 650 °C in 1% H 2 . We attributed this increase to the change of the oxidation state of Ce from Ce 4+ to Ce 3+ in ScCeSZ.…”

“…The coarsening of Ni, carbon deposition, or sulfur poisoning (in case of unprocessed natural gas) can take place during operation, although there are novel strategies to avoid/reduce these effects 4–6. In addition to already mentioned problems, Ni‐cermets have poor redox stability, which results in extreme sensitivity against different changes in operation regime and fuel gas composition 7–9.…”

A review on the preparation of anode materials and anode films for solid oxide fuel cell applications

“…Unlike screen-printing, this method is not suitable for mass production. For example, Zhang et al 75 used brush-painting to cover the electrolyte surface with Ag-GDC and Ni-F I G U R E 1 0 SEM images of Ni-GDC electrodes synthesized by the PLD method 65 [Colour figure can be viewed at wileyonlinelibrary.com] F I G U R E 1 1 Surface morphology of Ni-YSZ films after reduction A, without pre-annealing in the air and B, with pre-annealing in the air at 1200 C 181 GDC anode slurries, respectively. The OCV of SOFC with Ag-GDC anode was~1 V at 800 C but the OCV of SOFC with Ni-GDC continuously decreased from 1.2 to 0.85 V in 140 minutes under the same condition.…”

“…27 Some of the approaches that are used to synthesize anode materials including ball milling, [28][29][30][31][32] solid-state reaction (SSR) method, [33][34][35] template-based synthesis method, [36][37][38] and wet chemical methods (WCMs), such as sol-gel, 15,[39][40][41][42][43][44][45] co-precipitation, [46][47][48][49] hydrothermal and solvothermal methods, 48,50,51 and combustion method. [52][53][54][55][56][57][58] Various deposition methods were also discussed and categorized in several groups including physical deposition, [59][60][61][62][63][64][65][66] chemical deposition, [67][68][69] and colloidal deposition. 32,[70][71]…”