Current - Voltage Variation and Voltage Stability at Constant Load for a PEMFC System with Different Bipolar Plate Flow Fields

Water and hydrogen transport modelling through the membrane-electrode assembly of a PEM fuel cell

“…From those measurements it was observed an important increase of exergetic efficiency, with 1.5%-11% between current densities of 0.1-0.7 A cm -2 , for one of the fuel cells tested at the higher backpressure (P b,c /P b,a =70/70 kPa) [31]. This exergy gain was attained with the compromise of higher voltage oscillations at current densities over 0.4 A cm -2 and with lower voltage stability at a constant load of 0.5 A cm -2 [32]. It was also demonstrated experimentally by other researchers that a backpressure increasing from 1 to 3 atm inside a PEM fuel cell testing system at cell temperature of 70 °C and 100% relative humidity produced an enhancement of the average oxygen partial pressure inside the cell and also an increase in the fuel cell electrical performance [33].…”

“…Another set of measurements was conducted with the same BEKKTECH BT-552 testing system under similar humidity and temperature testing conditions, but at different inlet pressures for anode and cathode: 300 kPa and 200 kPa, respectively and at two different backpressures P b,c /P b,a (kPa) : 30/30 and 70/70 [31,32]. From those measurements it was observed an important increase of exergetic efficiency, with 1.5%-11% between current densities of 0.1-0.7 A cm -2 , for one of the fuel cells tested at the higher backpressure (P b,c /P b,a =70/70 kPa) [31].…”