Experimental investigation of a direct methanol fuel cell with Hilbert fractal current collectors

Abstract

The Hilbert curve is a continuous type of fractal space-filling curve. This fractal curve visits every point in a square grid with a size of 2 × 2, 4 × 4, or any other power of two. This paper presents Hilbert fractal curve application to direct methanol fuel cell (DMFC) current collectors. The current collectors are carved following first, second, and third order Hilbert fractal curves. These curves give the current collectors different free open ratios and opening perimeters. We conducted an experimental investigation into DMFC performance as a function of the free open ratio and opening perimeter on the bipolar plates. Nyquist plots of the bipolar plates are made and compared using electrochemical impedance spectroscopy (EIS) experiments to understand the phenomena in depth. The results obtained in this paper could be a good reference for future current collector design. © 2014 Jing-Yi Chang et al.