A review of accelerated conditioning for a polymer electrolyte membrane fuel cell

Abstract

a b s t r a c tA newly fabricated polymer electrolyte membrane (PEM) fuel cell usually needs a so-called breakin/conditioning/incubation period to activate it and reach its best performance. Typically, during this activation period the cell performance increases gradually, and then reaches a plateau without further increase. Depending on the membrane electrode assemblies, this process can take hours and even days to complete, which consumes a considerable amount of hydrogen fuel, leading to a higher operating cost. To provide for accelerated conditioning techniques that can complete the process in a short time period, this paper reviews established conditioning protocols and reported methods to condition PEM single cells and stacks, in an attempt to summarize available information on PEM fuel cell conditioning and the underlying mechanisms. Various techniques are arranged into two categories: on-line conditioning and off-line conditioning. For each technique, the experimental procedure and outcomes are outlined. Finally, weaknesses of the currently used conditioning techniques are indicated and further research efforts are proposed.Crown

Accelerated conditioning for a proton exchange membrane fuel cell

“…Assessment of temperature effects was performed at 50 • C, 70 • C (baseline), and 90 • C, at a constant voltage of 0.6 V and 100%RH on both sides for 6 h. To determine the effect of cycling steps, three experiments were carried out: (1) the cell was cycled between 0.6 V and 0.3 V, with each set point held for 60 s, and the cycle was repeated for 6 h. (2) The cell was cycled between 0.6 V, 0.3 V, and OCV, with each set point held for 60 s, and the cycle was repeated for 6 h. (3) The cell was cycled in a sequence of potential cycling steps, as follows: To investigate the influence of cycling frequency, two other tests were added: the cell was cycled between 0.6 V and 0.3 V, with each set point held for (1) 5 min or (2) 20 s. The conditions of all these tests were the same as for the baseline. Each conditioning process was performed for 6 h, and EIS, CV, and LSV were measured immediately afterward.…”

“…Depending on the membrane electrode assemblies (MEAs), this process can take hours and even days to complete. An ideal scenario is not only to have the highest possible power density after the breakin procedure, but also to minimize the activation completion time [2,3].…”

Initial conditioning of Polymer Eelectrolyte Membrane fuel cell by temperature and potential cycling

“…1 During this period the performance of the fuel cell gradually increases until it reaches its final value. Depending on the membrane electrode assembly (MEA) and the break-in procedure, this process can take hours or even days to complete.…”

“…As a consequence, there is a general lack of understanding of the fundamentals going on within the MEA during the break-in process and there are more hypotheses than facts. 1 Several conditioning protocols have been applied, patented and/or proposed, including both on-line methods, such as current control, potential control, short-circuiting and hydrogen pumping, as well as off-line methods like MEA steaming. 1,2,3 There were even attempts to standardize the process but the choice of break-in procedure still lies with the practitioner.…”

“…1 Several conditioning protocols have been applied, patented and/or proposed, including both on-line methods, such as current control, potential control, short-circuiting and hydrogen pumping, as well as off-line methods like MEA steaming. 1,2,3 There were even attempts to standardize the process but the choice of break-in procedure still lies with the practitioner. 4 In general, it is accepted that high temperatures and high humidities coupled with high currents and/or load cycling are beneficial for the successful initial conditioning.…”