Scientists at Stanford develop water splitter that runs on ordinary AAA battery

http://news.stanford.edu/news/2014/august/splitter-clean-fuel-082014.html

by happyscrappy • 12 years ago

46 61 12 years ago

news.stanford.edu

partacus2• 12 years ago

How is this a story? Did someone at Stanford open up a grade 10 Chemistry textbook?

digikata4• 12 years ago

From the article: "Using nickel and iron, which are cheap materials, we were able to make the electrocatalysts active enough to split water at room temperature with a single 1.5-volt battery. This is the first time anyone has used non-precious metal catalysts to split water at a voltage that low. It's quite remarkable, because normally you need expensive metals, like platinum or iridium, to achieve that voltage."

partacus2• 12 years ago

But it really isn't. The only thing of minor note here is room temperature vs doing it at 60 deg C.

mikexstudios3• 12 years ago

They're overselling the science. This is certainly not the first time anyone has used non-precious metals to split water at low voltages. Both Ni oxide and Ni-Fe oxide systems that they use in their paper are well known in the literature. Ni oxides have been published back in the 1950s while Ni-Fe oxide catalysts were introduced in the 1980s. However, they do claim that their NiO/Ni/CNT system is novel, which may be true.

In their experimental setup, they target 20 mA/cm2 current density. To achieve that, they can just increase the amount of catalyst they use. The geometric area (cm2) will remain the same, but the surface area will increase which will correspondingly raise current density. For example, one can stack sheets of carbon aerogel to achieve the same current density.

z131• 12 years ago

"But scientists have yet to develop an affordable, active water splitter with catalysts capable of working at industrial scales." "The nickel/nickel-oxide catalyst significantly lowers the voltage required to split water, which could eventually save hydrogen producers billions of dollars in electricity cost"

Making it more plausible I suppose. The only thing I have a problem with is that they used a battery, which required electricity to be initially charged. The electricity had to be generated somehow. If we plan to use <insert renewable energy here> to charge the batteries to split the water to generate the hydrogen to power our cars, I think very few people will be driving.

skybrian• 12 years ago

You wouldn't actually use a battery. It just makes a neat demo.

jostmey• 12 years ago

Agreed! I remember doing something similar for my science fair. Unless these scientist at Stanford have devised a way to dramatically improve the efficiency of the process then this is not a discovery at all!

adultSwim• 12 years ago

Article seems to be a bit dumbed down. Many people are familiar with the school experiment where you do electrolysis using a battery (A water splitter from an ordinary AAA battery!!!)

Article links to the paper. Unfortunately only the abstract is free. Seems like the advance is making it more efficient. Electrolysis at a usable level with just AAA-level voltage.

lutorm10• 12 years ago

... and not a single word about how the necessary electricity needed to make this "zero emission fuel" is supposed to be produced.

Plus, all I know about hydrogen points to it not being anything close to "an ideal fuel for powering vehicles, buildings and storing renewable energy". It has very low density, requires cryogenic storage or very heavy pressure vessels, migrates through materials, and is explosive when mixed with air.

digikata4• 12 years ago

See also "hydrogen embrittlement" http://en.wikipedia.org/wiki/Hydrogen_embrittlement Many materials you might select to carry hydrogen are weakened by it.

Crito• 12 years ago

Even when cryogenic (and hydrogen needs to be deeply cryogenic to remain liquid. 20K compared to liquid nitrogen's 77K) it is not particularly dense. It barely makes sense to use it in rockets since it has such poor density, causes embrittlement, and requires a great deal of insulation if you want to store it for any reasonable amount of time.

If it is a chore to use the stuff for rocket science, I don't see it becoming a reasonable power source in more casual applications.

If I am factually incorrect about anything here, I honestly do want to be told so.

nardi7• 12 years ago

This is like commenting on a battery tech article with, "Yes, but how are we going to charge all of those batteries?!" Or power grid technology, "Great, but where is the electricity going to come from?!?!"

aidenn0• 12 years ago

There is no mention of efficiency either; the efficiency of hydrolysis is often around 50% which means that almost anywhere you live it would be better from a CO2 standpoint to just put gas in your car.

lutorm10• 12 years ago

Well, if they claimed that using batteries was "emissions free", I would complain about that, too.

With hydrogen, the issue issue is that (at least to my understanding) if you have electricity, we already have a far more efficient solution: put the electricity directly into a battery and use it to power a motor. Going the route over electrolysis->hydrogen storage->fuel cell imposes such efficiency penalties that it would need extremely compelling other advantages to be competitive, and I don't see them.

justin662• 12 years ago

... and not a single word about how the necessary electricity needed to make this "zero emission fuel" is supposed to be produced.

At some point you have to trust the reader to understand things that are completely obvious. That's a necessary quality of good writing, even if you're adhering to the newspaper standard of targeting someone at the 8th grade reading level.

jacquesm2• 12 years ago

But in the case of Hydrogen such 'completely obvious' things are actually not all that obvious to the target audience. So it's ok to spell it out to avoid the risk of overselling a new technology and thus create a situation where it will fail to deliver due to unrealistic expectations.

Hydrogen is not exactly the easiest compound to work with and how it is generated is a huge part of equation.

mikexstudios3• 12 years ago

They didn't comment about it because it's not relevant. As nardi and others have said, think of water splitting as a battery... or a way to store energy as a chemical fuel (i.e. hydrogen gas). Because your energy input can come from any source, it doesn't matter.

Agree that hydrogen isn't an ideal fuel though. They're overselling that point. But the science is about how to split water efficiently. It's outside the scope of this research to address how to handle and use hydrogen after that.

digikata4• 12 years ago

I'm skeptical of hydrogen infrastructure using direct hydrogen too, and assume you need some other way to store and release the hydrogen. http://en.wikipedia.org/wiki/Hydrogen_storage I would think it would be more interesting to electrolyze directly into some storage material. But then, I'm just a casual observer in this topic area...

sirdogealot• 12 years ago

This isn't news.

"The researchers also plan to develop a water splitter than runs on electricity produced by solar energy."

Unfortunately that approach would be less efficient that simply transferring the electrical energy to an electric motor.

Light > Electricity > Hydrogen > Electricity > Electric Motor

is longer than

Light > Electricity > Electric Motor

kstenerud• 12 years ago

For a motor vehicle, you need Energy > Storage > Motor, so Light > Electricity > Electric Motor won't work in this case.

nardi7• 12 years ago

Ignorance. The news here isn't "we discovered electrolysis!" It's "we developed a new, efficient, and cheap electrocatalyst!"

Did you do that when you were 9 too?

jacquesm2• 12 years ago

Actually, the kids chemistry book that I read as a 10 year old or so had a very clear picture in it of one of the electrodes made of a guilder (dutch coin at the time) and noted it worked better than other coins because of its high nickel content.

That may have been coincidence but it certainly wasn't new knowledge to me that Nickel works well as an electrode when splitting water in Hydrogen and Oxygen.

I wished I'd kept my books from childhood and I'd be able to show you. It wasn't a particular fancy set either, just a bunch of test tubes, some leads to attach to a 4.5 V flat battery (I haven't seen those in ages either) and a bunch of basic chemicals.

kazinator3• 12 years ago

Efficiency isn't everything. If you want to transfer solar energy directly to a mobile motor, such as one which moves a car, the solar cells to do that have to be mounted on that car, oops! How big is that?

Using non-mobile solar cells to produce an energy-dense fuel which is portable makes sense, even if there is an efficiency hit.

Cars themselves are not efficient no matter how they are powered, because utmost efficiency in a car means lying on your back in a narrow, feather-weight, fragile aerodynamic tube with wheels, going about 25 mph max, and taking minutes to get to that speed. Forget niceties like air conditioning.

nardi7• 12 years ago

I'm amazed at the ignorance in these comments.

First, yes this is cool new science. No one imagined nickel would work as a water-splitting electrocatalyst. This is very surprising, and awesome.

Second, the point of water-splitting is obviously not power generation. It's power storage, just like a battery, but with better transport and storage characteristics.

alex_duf2• 12 years ago

right, but using a AAA battery which is already storing energy doesn't serve any purpose.

But I agree with you, efficient-cheap catalyst is needed indeed. I'd like to know the efficiency of the system though...

petersellers• 12 years ago

Using a AAA battery demonstrates that the process can be done using low voltage.

kazinator3• 12 years ago

Even if we imagine ourselves in a crazy world in which banks of actual AAA batteries are used for water splitting (not only to demonstrate the low voltage) there can still be an advantage.

A cylinder full of compressed hydrogen weighs less than a trunk full of AAA batteries, which cuts into economy.

The clunky bank of AAA batteries can be stationary in some water-splitting plant, whereas the hydrogen is light and portable.

mikexstudios3• 12 years ago

"No one imagined nickel would work as a water-splitting electrocatalyst."

Not true. It has been known since the 1950s (and likely earlier) that Ni oxides can function as water splitting catalysts (both for hydrogen evolution and oxygen evolution half reactions).

nardi7• 12 years ago

Of course you're right. I meant that no one thought nickel oxides would be practical compared to noble metal catalysts. I haven't read the article, but I assume they're using some kind of novel nanostructuring to increase the catalytic activity.

crististm• 12 years ago

I don't know about ignorance, but basically, the energy you get from splitting the water molecule (in the form of H2 and O2) is lower than the energy consumed to make the split. For storage you will also have to deeply freeze the gases unless you want to have huge tanks for storage

So what makes a hydrogen exposed freezing tank better suited for transport and storage than a chemical battery?

nardi7• 12 years ago

This is just pessimism. Yes, there are other hurdles to overcome for hydrogen. But this is a major advance in one of the primary pieces necessary for a hydrogen economy. What makes you think advances in other areas are impossible?

And to answer your question, much better energy density by mass.

cjensen• 12 years ago

A car which runs on hydrogen can be refueled in a few minutes. Batteries need an hour of charge or a battery swap which costs labor.

digikata4• 12 years ago

It's not, but it might be interesting for electrical storage of excess renewable energy, especially in concert with a less reactive storage material. http://en.wikipedia.org/wiki/Hydrogen_storage Though many places seem to want to solve the issue for cars, while to me it makes more sense to solve it for buildings before making it portable enough for cars.

lutorm10• 12 years ago

Give me a break. Did you read the article?

Although touted as zero-emissions vehicles, most of the cars will run on hydrogen made from natural gas, a fossil fuel that contributes to global warming. Now scientists at Stanford University have developed a low-cost, emissions-free device that uses an ordinary AAA battery to produce hydrogen by water electrolysis.

You don't agree the juxtaposition gives the impression that the latter alternative won't contribute to global warming?

Edit: just to be clear, I'm not saying the research isn't useful. My issue is with the article.

dang3• 12 years ago

Give me a break. Did you read the article?

Please don't be personally rude on Hacker News. This comment would be fine without the first two sentences.

ChaoticGood• 12 years ago

Reminds me of Stanley Meyer's invention: http://youtu.be/Vd7QL1-NnlU A claim of hydrogen obtained by water splitting fueled car. Very intriguing case of potential pseudo science.

kazinator3• 12 years ago

Presumably the low voltage saves energy. If a given number of electrons produce the same quantity of H using two different methods, that means the yield is related to current, and is the same for both methods, ampere for ampere. And so the higher voltage method will have a bigger dissipation (product of voltage and current).

Still, as a user, I don't care about voltage. How many kWh of energy does it take to produce n grams of hydrogen with this method, and how does it compare to existing methods.

Give me the highest relevant abstraction related to energy use.

MichaelAO• 12 years ago

I came across this video of Mike Strizki showing off his hydrogen setup during my freshman year of college. I'll never forget it: https://www.youtube.com/watch?v=XcIbOkakkDQ

Scientists at Stanford develop water splitter that runs on ordinary AAA battery

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