Analytical solutions for extended surface electrochemical fin models

• Published in: Journal of power sources 2014-11, Vol.265, p.282-290
• Main Authors: Cassenti, Brice N., Nelson, George J., DeGostin, Matthew B., Peracchio, Aldo A., Chiu, Wilson K.S.
• Format: Article
• Language: English
• Subjects: Analytical; Applied sciences; Computer simulation; Conical; Curvature; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrodes; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Exact solutions; Fuel cells; Hyperbolic; Mathematical analysis; Mathematical models; Microstructure; Potential drop; SOFC; Solid oxide fuel cells; Spherical
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2014.02.113

Exact solutions were obtained for variations in the potential and the current for three axisymmetric geometries, with positive, negative and zero curvatures, which simulate current transport in fuel cell electrodes. These solutions can be used to assess the influence of geometry on performance for three dimensional electrode microstructures. A solid oxide fuel cell (SOFC) electrode was selected as a test case for these studies. From the exact solutions, simulations of current flow and potential drop for one dimensional networks in SOFC electrodes were performed. Numerical tests demonstrated that surfaces with positive curvature have greater current flow for the same potential drop due to higher current losses through the lateral surface area. The study also showed that zero curvature solutions will be sufficiently accurate for positive or negative curvature geometries for moderate radius changes, but differ significantly from positive or negative curvature solutions for more extreme radius changes. Analytical solutions indicate fundamental differences in geometry and its influence on current flow. Based on the results of the simulations, an approximate solution, based on one non-dimensional parameter, was developed for estimating the effects of extreme changes in cross-section area. •Exact solutions were obtained to simulate current passages in SOFC electrodes.•A solid oxide fuel cell (SOFC) electrode was selected as a test case for these studies.•Assess geometry influence 3-D electrode microstructure on performance.•Performance was correlated to geometrical changes in the electrode.