Electronic devices like MP3 players and laptop computers may become dramatically more portable thanks to engineers from Purdue University, Indiana, who Monday unveiled a new method of using fuel cells, powered by hydrogen instead of methanol, to automatically recharge batteries.
Fuel cells could enable portable devices to run longer before needing to recharge. Although manufacturers have been developing direct methanol fuel cell (DMFC) technology, that approach has a few drawbacks, including low power density and the need for a catalyst to ignite the reaction between the methanol, air, and water to produce electrical power, which then gives off carbon dioxide as a byproduct.
Hydrogen fuel cells can provide more energy than their methanol counterparts, but a key problem has always been hydrogen storage. It is not possible to use high-pressure hydrogen gas containers or liquid hydrogen in portable electronic devices.
Now, Purdue researchers Evgeny Shafirovich, Victor Diakov, and Arvind Varma have found a solution to the problem of storing and generating hydrogen to drive fuel cell power systems in portable electronic devices.
How it works
Purdue's new hydrogen-producing technique uses the chemical compound sodium borohydride, a gel created by combining water with polyacrylamide and tiny aluminum particles, plus a combination of two known methods for producing hydrogen. One method, developed during World War II by Purdue chemist and Nobel laureate Herbert C. Brown (who discovered sodium borohydride), requires expensive catalysts to produce hydrogen; the other method ignites aluminum in water to produce hydrogen.
"Our solution is to combine both methods by using what we call a triple borohydride-metal-water mixture, which does not require a catalyst and has a high enough hydrogen yield to make the method promising for fuel cell applications," Varma says. "So far we have shown in experiments that we can convert 6.7 percent of the mixture to hydrogen, which means that for every 100 grams of mixture we can produce nearly 7 grams of hydrogen, and that yield is already better than alternative methods on the market."
Shafirovich says that with further study, the research team expects the conversion yield to increase to around 8 to 10 percent.
Another benefit of the new method, Shafirovich says, is that its byproducts are benign and recyclable -- hydrogen is nontoxic and very safe.
What it means to consumers
Here's how Shafirovich and his colleagues envision their invention's real-world application.
Consumers would install the fuel cells as small credit-card-size cartridges. The fuel cell would contain pellets of hydrogen-storing mixture, as well as an ignition system and a microprocessor. When a battery's energy level deteriorated, the microprocessor would initiate the combustion of a pellet, generating hydrogen to power the fuel cell. That would provide energy to recharge the battery. Once all the pellets on a cartridge had been consumed, a new cartridge would need to be inserted.
While it is hard to say exactly how many portable electronic devices exist worldwide, conservative estimates put the number at more than 1 billion. These fuel cells could eliminate the need to plug in notebook computers and could power not only portable DVD players, PDAs, and digital cameras, but also defibrillators, infusion pumps, and handheld medical diagnostic devices, for example. Of course, for this type of system to work, the portable consumer electronics devices would have to be redesigned.
Shafirovich says the military could also benefit "because soldiers need power for many electronic devices and it's hard to find plugs in the battlefield." And he added that the technology could also be used to power devices used by NASA to power electronic hardware in space.
Although the group has filed a provisional patent application, Shafirovich says that in order to complete basic research over the next two years, the researchers need US$600,000 to improve their current technology. They hope to build a demonstration unit to showcase their integrated hydrogen-powered fuel cell system.
The university is also looking for private investors to take the research to the marketplace. According to Karen White, a technology licensing manager in the office of Technology Commercialization at the Purdue Research Foundation, they are still in the very early stages of making that happen.
"We are currently soliciting interest from those in the industry to take it from the academic arena into the real world of research and development within the industry," she said.
So when will hydrogen-powered fuel cell technology reach consumers?
"It depends on how successful we are at raising funds and if investors are interested in our product," Shafirovich says. "I don't know about one year, but everything moves very fast in the electronics industry, so it's probably safe to say sometime in the near future."