PolyFuel, a Mountain View, California technology company, has approached the fuel cell problem from a different angle. It doesn’t aspire to build a better power source, but rather to make current designs work better by refining its central component: the membrane.
At its heart, a fuel cell is essentially a two-sided chemical reaction chamber — an anode and a cathode, separated by a membrane. The fuel cell creates power by splitting fuel molecules on one side — the anode — into positive protons and negative electrons, and running the negative particles out.
The membrane, a specially treated material which typically looks like a piece of cellophane, is in essence the straw that stirs the drink. Coated with a catalyst such as platinum power on carbon paper, the membrane encourages the positive protons to pass through it and react with oxygen (creating a by-product of water), while forcing the electrons to flow out of the cell where they create electrical current.
No matter what kind of fuel is being used, the membrane plays a central role in the whole process. And it’s a tricky job at that. The material used to make the membrane needs to survive a challenging environment, while acting as a conductor and an insulator. The membrane’s performance makes a big difference in how much energy is created, how much excess water or humidity is produced, and how durable and expensive the fuel cell is.
Believers say that fuel cells could eventually replace the gas tanks in our cars, and, in the shorter term, the batteries in our portable devices. Over the years, companies have experimented with a variety of potential fuels, but in general, the most popular developments have focused on hydrogen fuel cells for cars and methanol for “micro fuel cells”, those smaller versions of the power source used to run cell phones, laptops and the like.
While fuel cells have gained notoriety recently as the future consumer electronics’ power source, hydrogen-based fuel cells have been used for decades to create power and water on space missions. Materials such as DuPont’s Nafion have been used for the membrane for these fuel cells, but would-be competitors such as PolyFuel say that these traditional membranes are not ideally suited to the needs of a fuel cell that would power a car or a laptop.
“They’ve taken [the same] technology designed for the Gemini space program and tried to shoehorn it into auto and portable applications,” says Jim Balcom, president and CEO of PolyFuel.