Abstract
Laminar flow fuel cells (LFFCs) overcome some key issues - most notably fuel crossover and water management - that typically hamper conventional polymer electrolyte-based fuel cells. Here we report two methods to further minimize fuel crossover in LFFCs: (i) reducing the cross-sectional area between the fuel and electrolyte streams, and (ii) reducing the driving force of fuel crossover, i.e. the fuel concentration gradient. First, we integrated a nanoporous tracketch separator at the interface of the fuel and electrolyte streams in a single-channel LFFC to dramatically reduce the cross-sectional area across which methanol can diffuse. Maximum power densities of 48 and 70 mW cm-2 were obtained without and with a separator, respectively, when using 1 M methanol. This simple design improvement reduces losses at the cathode leading to better performance and enables thinner cells, which is attractive in portable applications. Second, we demonstrated a multichannel cell that utilizes low methanol concentrations (<300 mM) to reduce the driving force for methanol diffusion to the cathode. Using 125 mM methanol as the fuel, a maximum power density of 90 mW cm-2 was obtained. This multichannel cell further simplifies the LFFC design (one stream only) and its operation, thereby extending its potential for commercial application.
Original language | English (US) |
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Pages (from-to) | 3523-3528 |
Number of pages | 6 |
Journal | Journal of Power Sources |
Volume | 195 |
Issue number | 11 |
DOIs | |
State | Published - Jun 1 2010 |
Keywords
- Fuel cell
- Laminar flow
- Methanol crossover
- Multichannel
- Separator
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Energy Engineering and Power Technology
- Renewable Energy, Sustainability and the Environment
- Physical and Theoretical Chemistry