Scientists and engineers at the U.S. Army Research Laboratory (ARL) in Maryland have demonstrated a new nanomaterial powder that creates large amounts of energy by simply mixing it with water.
Credit: U.S. Army Research Laboratory
The substance is described as a nano-galvanic aluminium-based powder. It creates a bubbling reaction that splits apart water – two molecules of hydrogen and one of oxygen.
"The hydrogen that is given off can be used as a fuel in a fuel cell," said Scott Grendahl, a materials engineer and team leader. "What we discovered is a mechanism for a rapid and spontaneous hydrolysis of water."
It has already been known for a long time that hydrogen can be produced by adding a catalyst to aluminium. However, this normally takes time and requires elevated temperatures, added electricity and/or toxic chemicals. By contrast, the nanomaterial powder seen here does not require a catalyst and is very fast. The team calculates that one kilogram of the powder can produce 220 kilowatts of energy in just three minutes, which is doubled if you consider the amount of heat energy produced by the exothermic reaction.
"That's a lot of power to run any electrical equipment," said Dr. Anit Giri, a physicist for the Weapons and Materials Research Directorate. "These rates are the fastest known without using catalysts such as an acid, base or elevated temperatures."
As seen in the video, the team demonstrated a small radio-controlled tank powered by the powder and water reaction. They believe their discovery is dramatic in terms of future potential. It could be 3-D printed and incorporated into future air or ground robots. These self-cannibalising machines would feed off their own structures, then self-destruct after mission completion. It could also help future soldiers to recharge mobile devices for recon teams.
"There are other researchers who have been searching their whole lives and their optimised product takes many hours to achieve, say 50% efficiency," Grendahl said. "Ours does it to 100% efficiency in less than three minutes."
"The important aspect of the approach is that it lets you make very compact systems," notes Anthony Kucernak from Imperial College London, who was not involved in this particular study, but is an expert on fuel cell technology. "That would be very useful for systems which need to be very light or operate for long periods on hydrogen, where the use of hydrogen stored in a cylinder is prohibitive."