Hydrogen fuel cells may sound futuristic but they’ve actually been around for a long time – conceptually, hydrogen cells have been kicked around by physicists since the 1800s (yes, seriously) and functionally, the past decade has seen various auto manufactures create concept cars for this fuel type. The problem has always stemmed from overall efficiency of fuel cells, making it a fairly nascent (and unprofitable) industry.
That may change, as aluminum is opening the door to practical innovations that may revolutionize the hydrogen cell industry. A Japanese research team has found that a new aluminum alloy works more effectively than previous alloys based on magnesium, sodium, and boron. From Science News:
Lightweight interstitial hydrides — compounds in which hydrogen atoms occupy the interstices (spaces) between metal atoms — have been proposed as a safe and efficient means for storing hydrogen for fuel cell vehicles. Hydrides using magnesium, sodium and boron have been manufactured, but so far, none have proven practical as a hydrogen repository. An aluminum-based alloy hydride offers a more viable candidate because it has the desired traits of light weight, no toxicity to plants and animals, and absence of volatile gas products except for hydrogen. Until now, however, only complex aluminum hydrides — unsuitable for use as a hydrogen storage system — have been created.
In a recent paper in the AIP Publishing journal APL Materials, a joint research group with members from the Japan Atomic Energy Agency (Hyogo, Japan) and Tohoku University (Sendai, Japan) announced that it had achieved the long-sought goal of a simple-structured, aluminum-based interstitial alloy. Their compound, Al2CuHx, was synthesized by hydrogenating Al2Cu at an extreme pressure of 10 gigapascals (1.5 million pounds per square inch) and a high temperature of 800 degrees Celsius (1,500 degrees Fahrenheit).
Aluminum is already a key component in increasing fuel efficiency because of its lightweight and strong material properties. However, this is the first time that aluminum has been discussed as a component of changing the fuel mechanism itself. The impact of this research probably won’t be felt for several years, but the possibilities of more effective hydrogen-based power (where water vapor is the only emission) is good news from a global economic and environmental standpoint.