Design and evaluation of polymer-electrolyte and direct-methanol fuel cells for electric vehicles

摘要

Fuel cells (FC) are a promising power source for electric vehicles (EV), but they have not yet become practical for widespread application because of remaining technical difficulties. Polymer electrolyte membrane fuel cells (PEFC) are expected to become the first practical FCs, but direct methanol FCs (DMFC) use a simpler reaction mechanism than PEFCs and consume less energy. Therefore, DMFCs are attractive and are currently being developed. They are now at the experimental stage and many reports on reaction mechanisms and single-cell performance have been published. We evaluated the performance of PEFCs and DMFCs based on weight, volume, cost, CO_2 emissions, and energy requirements for manufacturing and operation. We also compared the fuel efficiency and CO_2 emissions of these FCs to internal combustion engine-equipped vehicles (ICEVs), and determined the travel patterns for FCEVs that minimize energy consumption. The DMFC system yielded 1.1% higher vehicle fuel economy than the PEFC system. DMFC EVs operating at a constant power output of 20 kW had fuel economy equivalent to about 23km/1 for a 10.15 driving mode and 38km/1 at a steady 20km/hr compared with 17km/1 and 28km/1 for PEFCs, respectively.