Researchers at the US Army Research Laboratory (ARL) have discovered that a nano-galvanic aluminum-based powder of their design splits water on contact, producing hydrogen and oxygen. Scientists have known for a long time that hydrogen can be produced by adding a catalyst—such as sodium or potassium hydroxide or an acid—to aluminum. However, these methods take time, elevated temperature, and added electricity.
The ARL powder does not need a catalyst; it is also very fast. “We have calculated that one kilogram of aluminum powder can produce 220 kW of energy in just three minutes. That’s a lot of power to run any electrical equipment. These rates are the fastest known without using catalysts such as an acid, base or elevated temperatures,” said Dr. Anit Giri, a physicist with the lab’s Weapons and Materials Research Directorate.
That metric doubles if you consider the amount of heat energy produced by the exothermic reaction, Giri said.
The team demonstrated a small radio-controlled tank powered by the powder/water reaction. Moments after mixing the powder with to a small amount of water, a bubbling reaction produced a great deal of hydrogen, which was then used to power the model around the laboratory.
We just take our material, put it in the water and the water splits down into hydrogen and oxygen. There are other researchers who have been searching their whole lives and their optimized product takes many hours to achieve, say 50 percent efficiency. Ours does it to nearly 100 percent efficiency in less than three minutes.—Scott Grendahl, a materials engineer and team leader
Because the nanomaterial powder has the potential to be 3-D printed, researchers envision future air and ground robots that can feed off of their very structures and self-destruct after mission completion.
Researchers said one possible application of the discovery that may help future soldiers is the potential to recharge mobile devices for recon teams.
These teams are out for a short number of days, three to five days, and a lot of that depends not only on their food supplies, but on how long their supplies last in terms of their equipment and right now that stems from lithium batteries. If we can recharge those batteries, they can stay out longer.—Scott Grendahl
The next steps are to document the discovery with papers and intellectual property protections, some of which are ongoing, and to coordinate further applications with scientists and engineers across the laboratory.
We all feel pretty good that this can contribute to a new kind of research to generate power at ease and at will.—Anit Giri