Science

Scientists create water splitter that runs on a single AAA battery

The Stanford University water splitter could save hydrogen producers billions of dollars (Photo: Mark Shwartz)
The Stanford University water splitter could save hydrogen producers billions of dollars (Photo: Mark Shwartz)

A new emissions-free device created by scientists at Stanford University uses an ordinary 1.5-volt battery to split water into hydrogen and oxygen at room temperature, potentially providing a low-cost method to power fuel cells in zero-emissions vehicles and buildings.

The water splitter is made from the relatively cheap and abundant metals nickel and iron. It works by sending an electric current from a single-cell AAA battery through two electrodes.

"This is the first time anyone has used non-precious metal catalysts to split water at a voltage that low," chemistry professor and lead researcher Hongjie Dai says. "It's quite remarkable, because normally you need expensive metals like platinum or iridium to achieve that voltage."

The technology has huge potential as a source for powering hydrogen fuel cells, long held as a likely successor to gasoline. Unlike gasoline combustion, which emits large quantities of the greenhouse gas carbon dioxide, fuel cells combine stored hydrogen gas with oxygen from the air to produce electricity, leaving only water as a byproduct.

Fuel cell vehicles have been around since the 1960s, albeit mostly as research projects and demonstration cars and buses. But we may soon see them in commercial production, with Toyota and Honda both committed to selling fuel cell cars in 2015 and Hyundai already leasing fuel cell vehicles in Southern California.

Fuel cell vehicles have been widely criticized for their high cost, the lack of infrastructure around their fuel delivery, and their low energy efficiency after accounting for the effort it takes to produce compressed hydrogen (often involving large industrial plants that use an energy-intensive process that combines steam and natural gas).

But the new Stanford research, which latches onto a previously unknown method for splitting water, could help account for all these issues.

"It's been a constant pursuit for decades to make low-cost electrocatalysts with high activity and long durability," Dai explains. "When we found out that a nickel-based catalyst is as effective as platinum, it came as a complete surprise."

The nickel-metal/nickel-oxide catalyst, discovered by Stanford graduate student Ming Gong, also requires significantly lower voltages to split water when compared to pure nickel or pure nickel oxide. This new technique is not quite ready for commercial production, though.

"The electrodes are fairly stable, but they do slowly decay over time," Gong says. "The current device would probably run for days, but weeks or months would be preferable. That goal is achievable based on my most recent results."

The next step is to improve that decay rate and to test a version that runs on electricity produced by solar energy instead of the AAA battery.

The researchers believe that their water splitter could save hydrogen producers billions of dollars, and the electrolytic device could be used to make chlorine gas and sodium hydroxide as well as hydrogen fuel cells.

A paper published in the journal Nature Communications describes the research in more detail.

You can see Dai himself demonstrating the device in the video below.

Source: Stanford University

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33 comments
slam_to
Are you kidding me? This is straight out of a grade-school science book.
Joris van den Heuvel
@slam_to: me too, but not at this voltage, not at this efficiency and not with non-precious metal electrodes.
GabrielMarshman
I created an account just to say that this is ridiculous. I did this when I was 13-14. Is this what they spend their time on? Elementary school science fair level.
Hal Guernsey
So what! I this as a kid over fifty years ago--this must a stupid April Fool's joke. That electrolysis can be done is not the issue--you always have to put more energy into the system to isolate the hydrogen atoms than can be obtained from burning them. This is just. Dumb.
Strings
@slam_to, @GabrielMarshman
So... You guys had access to nickle oxide heterostructures on the sides of carbon nanotubes in highschool, set up in a previously unknown configuration that nearly bypasses Ostwald ripening?... That's pretty freaking impressive for an elementary school science fair.
Joris van den Heuvel
Doesn't anyone read the article anymore before commenting? This is nothing short of ground breaking. A clean way of splitting water, with almost no loss of energy and no need for precious metals, at a voltage of that of solar panels, so it doesn't require inverters. I am by no means an expert, but I think that's a significant breakthrough.
Jim Vanus
The actual news is that these Stanford researchers have discovered an economical electrode material which MAY be useful for large scale electrolysis production of hydrogen.
However, the principle barriers for hydrogen fuel cell use are hydrogen storage and distribution, not electrolysis electrode cost & efficiency.
In terms of energy efficiency, hydrogen produced by electrolysis requires more energy to produce than the hydrogen fuel yields. Efficiency is further lost during the fuel cell's conversion of hydrogen into electricity.
Unless the electricity powering the electrolysis is produced by "green" & "sustainable" means, the net effect on the environment is arguably worse than that of battery-powered cars recharged on the existing coal & gas fired power grid.
If these new electrodes can be scaled to industrial use, then this is a significant discovery. However, it is not a game changer because it doesn't solve the problems of "green" electricity for electrolysis and hydrogen storage & distribution.
Michiel Mitchell
This is SOOOOO cool.... We take electricity from a Duracell AAA.. we split water with it... we feed the gas into a fuel-cell and what do you know... we get electricity out the back of it... SUWEEEEEEEEET!
JweenyPwee
Jim Vanus...exactly. You cannot get more energy out of a system than that of what you put into it.
"Eureka! After the manufacturing process to procure raw materials (or even recycled) and refine them into usable products and using all the energy there required....we've produced a few bubbles storing a fraction of the energy required in the process to produce them! Praise Gore!"
"Green! Green! Buy! Buy!"
Eugarps71
As was already mentioned above, using a 1.5 volt battery for electrolysis is basic middle school science, but only if the water being split has impurities such as salt to allow it to conduct electricity. This article, and the linked one for Stanford, do not mention the water having salt in it. If this is the case and the water is pure, then this is a significant discovery, as electrolysis of pure water requires much higher voltages or expensive catalysts like platinum.