High performance dry feed hydrogen PEMFCs: Understanding the water balance as a design tool for novel polymer membranes

Designing and operating an efficient fuel cell which has very tight control over the water inventory of the cell, is a very powerful tool for designing new fuel cell membranes and fuel cell modeling. The power of autohumidified approach was demonstrated by designing a new fuel cell, which runs on completely dry feeds and is capable of operating, as well as commercial fuel cell test cells with fully humidified streams at the same operating conditions. CSTR fuel cell experiments were conducted on a custom designed in-house cell to ensure that the gas composition was uniform within the cell and that the liquid water produced within the cell would drain from the cell preventing flooding. It was possible to operate a fuel cell equally as well as commercially available fully humidified cells under the same operating conditions by controlling the water balance in the fuel cell. There were fewer limitations caused by mass transport at high current, which was attributed to flooding of the fuel cell. The internal resistance occurred at peak power, which was essentially the same for all cells. This is an abstract of a paper presented at the ACS Fuel Chemistry Meeting (Washington, DC Fall 2005).