Fuel Cell Electrode Properties

Relva C. Buchanan, University of Cincinnati Main Campus, DMR 0407569

Thin film materials with properties suitable for fuel cell electrode and active sensor device applications are in highly demand. For bipolar plate application in PEM fuel cells, for example, the coated electrodes will exhibit low contact resistance, good adherence, high catalytic activity, good corrosion resistance, compatible thermal expansion coefficient and low wetting angle, for good water management. A variety of coating materials, including graphite, conductive polymers, noble metals, metal nitrides and carbides have been evaluated, but with only limited success. Our Ni/NiO/ZrO2 thin films when coated onto stainless steel plates gave very good contact resistance under pressure (~10 ohm-cm2 at 400psi), but wetting was initially marginal (~45owetting angle), but was markedly improved on controlled oxidative treatment. These metallo-organic deposited (MOD) films, featuring nanoscale microstructures, good adhesion and low electrical resistance, were produced below 300C, a feature which enhances their utility as fuel cell electrode components. The composite films also exhibit sensitive resistive changes to dynamic pressure loading (piezoresistive), and to corrosive gas and infrared detection, indicating their versatility and value as sensor materials. Intellectual merit of this work is the new knowledge and understanding of interfacial reactions and percolation behavior, related to sensor and electrode characteristics in these film systems

The Work is Notable because:Of the ability to fabricate the Ni/NiO films below 300C, featuringhigh quality, good adherence, nanostructured morphology and controlled oxidation to manipulate surface propertiesThese films feature an unprecedented wide range of sensing capabilities, for temperature, pressure, gas, gas flow and IR radiation.The films show demonstrated utility for fuel cell/energy conversion applications.Broader Impact of Results1) Several important materials issues, related to interfacial reactions and sensor response characteristics would, if successfully addressed, have broad relevance to the successful development of rugged sensor devices that meet the demand, in the automotive, consumer, safety and environmental fields for selectivity in sensor performance. 2). The research will impact importantly on the training of graduate and undergraduate students, as well as high school students and their teachers who do sometimes participate in the research effort. Several theses should also result from this research, the findings from which have been widely disseminated through refereed publications, presentations, posters and the like.

Fuel Cell Electrode Properties

Relva C. Buchanan, University of Cincinnati Main Campus, DMR 0407569

Several undergraduate and graduate students have done projects in this ongoing area of sensor and related electroceramics research in our laboratories. This experience not only enhances their professional growth and co-op program work experience but also broadens their understanding of Materials Engineering, and their interest in graduate education. Students regularly participate in the presentation of posters and talks describing their results to an audience that includes high school and junior high students, their teachers and parents. Research demonstrations are also regularly given to special groups including minority and women pre-engineering students to increase interest in Materials Science and to aid in recruitment. with high sensitivity

Fuel Cell Electrode PropertiesRelva C. Buchanan, University of Cincinnati Main Campus, DMR 0407569