TY  - JOUR
N1  - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions.
TI  - Multi-length scale microstructural design of micro-tubular Solid Oxide Fuel Cells for optimised power density and mechanical robustness
EP  - 12
AV  - public
Y1  - 2019/09/15/
VL  - 434
JF  - Journal of Power Sources
KW  - Anode microstructure
KW  -  Knudsen diffusion
KW  -  Tortuosity factor
KW  -  Micro-channels
KW  -  Triple phase boundary
KW  -  Mass transport
A1  - Lu, X
A1  - Bertei, A
A1  - Heenan, TMM
A1  - Wu, Y
A1  - Brett, DJL
A1  - Shearing, PR
ID  - discovery10090156
N2  - In this study, we aim to parametrically reveal the dependence of electrochemical performance on a variety of microstructural characteristics at multi-length scale in a micro-tubular solid oxide fuel cell to shed light on the advanced electrode design. Numerical Direct Simulation Monte Carlo method is used on the tomographically-reconstructed 3D microstructure of the anode to characterise the tortuosity factors as a function of the porosity and pore diameter accounting for the Knudsen flow. These are subsequently incorporated in the mass transport in 2D electrochemical simulations. Results show that the Knudsen tortuosity factor is two times larger than that estimated by the continuum physics. High substrate porosity and pore size show unnoticeable effect in facilitating the mass transport provided that the micro-channels span over 60% of the radial thickness. The width and radial distribution of the micro-channels have little influence on the mass transport, but the compactness greatly affects the global performance. Optimal designs are identified as i) 80% micro-channel length and 27% substrate porosity to reach maximum power density (1.18?W?cm?2) with lowered mechanical strength, or ii) 60% micro-channels length and 27% porosity to obtain a more balanced performance (0.96?W?cm?2) with better long-term structural integrity.
UR  - http://dx.doi.org/10.1016/j.jpowsour.2019.226744
PB  - ELSEVIER
ER  -