Through-Plane Mass Transport Measurements

Dynamic Through-Plane Mass Transport Measurements 

Kim and Mench15 used high-resolution neutron imaging to visualize the liquid water flow in the through-plane direction under 

Preston, L. Bonville, H.R. Kunz, M. Perry, D. Condit, effect of water management schemes on the membrane durability in PEMFCs. ECS Trans. 16, 1697 (2008) 

Spernjak, S.G. Advani, A.K. Prasad, Simultaneous neutron and optical imaging in PEM fuel cells. J. Electrochem. Soc. 156, B109-B117 (2009) 

Elucidating differences between carbon paper and carbon cloth in polymer electrolyte fuel cells. Electrochimica. Acta. 52, 3965-3975 (2007) 

---

The improved neutron detector spatial resolution has been a recent advance, with user instruments first available at the end of 2006 and 2007 at NIST and PSI, respectively. The work can be classified as proof-of-principle,9,10 in situ measurement of the steady-state through-plane water content during fuel cell operation," 13 and dynamic through-plane mass transport measurements.14,15... 

Dynamic Through-Plane Mass Transport Measurements... 

One of the main parameters that would improve the overall performance of a fuel cell is better mass transport of reactants through the diffusion layer toward the active catalyst zones. In order to quantify and characterize how well the gas mass transport is in a specific DL material and design, it is important to measure the in-plane and through-plane permeabilities. Most of the published permeability results report the viscous permeability... 

The question to be dealt with now is how to measure mass transport. This is done by measuring the amount of material passed through some place during a certain length of time. In Fig. 6 the electrode is shown to lie in the y—z plane and the line of mass transport is along the x axis. The flux (which is the quantity to be measured) is that number of moles of material which pass during unit time (second) through a unit area (cm ) parallel to the y—z plane, in the x direction. The flux may depend on all coordinates, X, y and z, but in practice it is convenient to assume that all mass transport... 

---