Accelerated stress test protocol for solid oxide cell based on ex-situ artificial aging of the fuel electrode via redox-cycling - In memory of Prof. A. Milchev.

Vladikova, Daria; Krapchanska, Milena; Burdin, Blagoy; Sheikh, Asrar

Solid oxide cells (SOCs) attract industry due to their operation with non-platinum catalysts and high tolerance towards hydrogen quality. The coupling with other industrial processes increases their energy efficiency. They already entered market production for which the lifetime should go beyond 90,000 h. This requires a further decrease in the degradation rates to reach the accepted key performance indicators (KPIs) - one of the main research and technological targets. However, the bottleneck is the long-term tests which cannot be avoided. The problem-solving approach is the introduction of accelerated stress tests (ASTs), which are not yet developed. The first 12 AST protocols were elaborated in the FCH JU2 Project AD ASTRA applying in-situ aggravated tests of cells/stacks and ex-situ artificial aging of critical cell/stack single components. This paper gives detailed information about one of the protocols based on accelerated and governed ex-situ aging of the fuel electrode (Ni/YSZ) by chemical redox cycling, causing enhanced coarsening and migration of the Ni particles. A three-stage test procedure is developed. The performed mild oxidation is monitored by a specially introduced impedance-based approach. For quantitative evaluation of the accelerated degradation, electrochemical measurements are applied periodically during the aging in accelerated conditions. They are compared with data from previous field tests in nominal conditions. Comparative microstructural analysis is also performed. The acceleration is evaluated by the introduced acceleration factor (AF). It is presented by the ratio between the duration of a long-term test at nominal conditions and that measured at accelerated conditions, bringing to the same level of degradation. The application of the protocol demonstrates more than 50 times acceleration (AF ≈ 60).

SYNTHETIC fuels; ACCELERATED life testing; MANUFACTURING processes; REDOX polymers; CELLULAR aging; ELECTRODES; CYCLING competitions

Journal of Solid State Electrochemistry, 2024, Vol 28, Issue 5, p1743

1432-8488

Academic Journal

10.1007/s10008-024-05803-y