TY - JOUR
T1 - Nanoporous separator and low fuel concentration to minimize crossover in direct methanol laminar flow fuel cells
AU - Hollinger, A. S.
AU - Maloney, R. J.
AU - Jayashree, R. S.
AU - Natarajan, D.
AU - Markoski, L. J.
AU - Kenis, P. J.A.
N1 - Funding Information:
This work was supported through an STTR Phase II grant from ARO to INI Power Systems of Morrisville , NC and the University of Illinois at Urbana-Champaign ( W911NF-04-C-113 ). Financial support from the University of Illinois, from the National Science Foundation for a CAREER award to PJAK ( NSF CTS 05-47617 ), and from the US Army Core of Engineers’ Construction Engineering Research Laboratory (USACE-CERL) for a fellowship to ASH are also gratefully acknowledged. The authors thank Fikile Brushett for stimulating discussions.
PY - 2010/6/1
Y1 - 2010/6/1
N2 - 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.
AB - 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.
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U2 - 10.1016/j.jpowsour.2009.12.063
DO - 10.1016/j.jpowsour.2009.12.063
M3 - Article
AN - SCOPUS:75749132471
SN - 0378-7753
VL - 195
SP - 3523
EP - 3528
JO - Journal of Power Sources
JF - Journal of Power Sources
IS - 11
ER -