PolyFuel Announces New Milestone in Portable Fuel Cell Performance

November 12, 2006 by Jeff Shepard

PolyFuel, Inc. revealed that its new, ultra-thin membrane delivers what the company claims to be over 40% more power than any fuel cell membrane previously available. The new 20µ hydrocarbon membrane, when used in direct methanol fuel cells (DMFC) being developed for micro power applications such as notebook computers and cell phones, produces 200mW of peak power per square centimeter of material at 70°C – a level which allows for a significant reduction in the size, weight and cost of the fuel cell "stack," a key component in the fuel cell system.

Impressive results in this area were acheived by another PolyFuel hydrocarbon membrane, one 45µ thick, from which 140mW of peak power per square centimeter was obtained at similar conditions. Other materials, such as fluorocarbon membranes – considered by many to be at their "end of life" stage – have not been able to demonstrate such high power while maintaining acceptable efficiencies. The new membrane also allows more than twice the amount of water to diffuse through it than previous membranes, which can simplify the design of the fuel cell. During operation, water in the fuel-water solution is consumed on one side of the membrane (the anode) only to reappear on the opposite side (the cathode) as a by-product. PolyFuel's new membrane allows the water to diffuse back from the cathode to the anode, where it can participate in the reaction. This "molecular-level recycling" can eliminate the need for pumps, which are especially problematic in products intended for smaller applications such as cell phones or PDAs.

Samsung engineers indicated recently that the new membrane is a breakthrough from their perspective after conducting a rigorous series of tests on every fuel cell membrane that they could find. Said one of Samsung's Principal Engineers, "A fuel cell can never deliver too much power, or be too efficient. We expect that the new material, plus the strong support that PolyFuel is providing, will enable us to achieve a new performance milestone."

Unlike "legacy" fuel cell membranes made from fluorocarbon polymers such as the one found in non-stick Teflon®, PolyFuel's higher performing membranes utilize a hydrocarbon polymer chemistry. Jim Balcom, Chief Executive Officer of PolyFuel, commented: "The characteristics of PolyFuel's hydrocarbon membrane chemistry, such as high power density, low methanol crossover, and now high water back diffusion, allow for significantly improved flexibility in the design of portable fuel cells."

The performance results achieved by PolyFuel's new 20µ membrane were obtained using a commercially-available Johnson Matthey catalyst, and commercially-available gas diffusion layers (GDLs). Total catalyst loading was 5.6mg of platinum per square centimeter.