Novel Membranes and Intermediate Temperature Fuel Cells

In this phase I SBIR, T/J Technologies will demonstrate the use of an intermediate temperature (200-250oC) Direct Methanol Fuel Cell (DMFC). The fuel cell will be based on a novel polymeric membrane Polyvinazene (2-vinyl-4,5dicyanoimidazole). We willcollaborate with investigators from the University of Michigan who have developed new synthetic methods to produce this polymer and are the leaders in the field of imidazole based polymers. The Polyvinazene has high thermal stability (>300oC) and containselectron withdrawing cyano groups that increase the acidity of the imidazole. This should impart high proton conductivity at low levels of humidification and without requiring high concentrations of supporting acids. Easy processibility and low cost arealso advantages over other polymer materials previously suggested for use in fuel cells. Proton conductivities will be determined for undoped membranes and membranes doped with phosphoric or sulfuric acid. Promising candidates will be tested for methanolvapor and oxygen permeation and will be used in DMFC cells operating at 220oC. In Phase II we will use the best performing membrane from Phase I to demonstrate a compact DMFC stack with an output power of 20-50W and temperature of 250oC. Other fuels mayalso be considered in Phase II. This project will result in intermediate temperature direct methanol fuel cells based on a new family of polymer electrolytes. This fuel cell will provide high power density, low water dependency of the conductivity, and will not leach out acids. The newpolymer electrolytes could also significantly reduce the cost of PEMFC that operate on reformed hydrocarbons by substantially enhancing CO tolerance. The projected commercial cost of the membranes are $50/lb, significantly lower than Nafionr. Broadcommercial applications exist for intermediate temperature fuel cells, including portable/off-grid power supplies and vehicle propulsion.