Michael Ulsh

Overcoming the Range Limitation of Medium-Duty Battery Electric Vehicles through the use of Hydrogen Fuel-Cells

Battery electric vehicles possess great potential for decreasing lifecycle costs in medium-duty applications, a market segment currently dominated by internal combustion technology. Characterized by frequent repetition of similar routes and daily return to a central depot, medium-duty vocations are well positioned to leverage the low operating costs of battery electric vehicles. Unfortunately, the range limitation of commercially available battery electric vehicles acts as a barrier to widespread adoption. This paper describes the National Renewable Energy Laboratorys collaboration with the U.S. Department of Energy and industry partners to analyze the use of small hydrogen fuel-cell stacks to extend the range of battery electric vehicles as a means of improving utility, and presumably, increasing market adoption. This analysis employs real-world vocational data and near-term economic assumptions to (1) identify optimal component configurations for minimizing lifecycle costs, (2) benchmark economic performance relative to both battery electric and conventional powertrains, and (3) understand how the optimal design and its competitiveness change with respect to duty cycle and economic climate. It is found that small fuel-cell power units provide extended range at significantly lower capital and lifecycle costs than additional battery capacity alone. And while fuel-cell range-extended vehicles are not deemed economically competitive with conventional vehicles given present-day economic conditions, this paper identifies potential future scenarios where cost equivalency is achieved.

High Throughput and High Resolution In-Line Monitoring of PEMFC Materials by Means of Visible Light Diffuse Reflectance Imaging and Computer Vision

In this paper we present results from our recent work in which polymer electrolyte membrane fuel cell electrodes with intentionally introduced known defects were imaged and analyzed using a fuel cell scanner recently developed at the National Renewable Energy Laboratory. The defect types considered included particle debris, scuffs, scores, slits, and laser perforated pinholes. The debris defects were analyzed on samples from three different production stages, whereas the other defect types were introduced in a membrane tacked on a catalyst-coated diffusion media. We are showing that the fuel cell scanner can generate good quality, high resolution images of both baseline and defect-containing material. Based on the scanned images, an automatic, computer vision algorithm is developed that identifies presence and location of debris particles. The presented results clearly indicate that the in-line visible-light-diffuse-reflectance-based system can be successfully employed to monitor quality and to detect critical defects in fuel cell electrodes that are transported with high speed in a high volume manufacturing facility.Copyright