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

news.stanford.edu

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

#31

Post by epistasis »

lutorm wrote: post #24
nardi wrote: post #15

Earlier quoted context omitted.

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 ?!?!"

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 w…

Using the batteries is emissions free. Claiming anything else is just bringing emotional baggage and irrationality to the situation.

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

#32

Post by cjensen »

crististm wrote: post #21
nardi wrote: post #12

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.

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?

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.

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

#33

Post by jacquesm »

nardi wrote: post #26
sirdogealot wrote: post #9

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

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?

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.

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

#34

Post by mikexstudios »

lutorm wrote: post #6

... 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 mix…

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.

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

#35

Post by alex_duf »

petersellers wrote: post #30
alex_duf wrote: post #18

Earlier quoted context omitted.

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...

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

ooh, alright, now it makes sense to me. Thanks.

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

#36

Post by jacquesm »

justin66 wrote: post #25
lutorm wrote: post #6

... 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 mix…

> ... 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.

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.

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

#37

Post by adultSwim »

partacus wrote: post #2

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

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.

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

#38

Post by lutorm »

epistasis wrote: post #31
lutorm wrote: post #24

Earlier quoted context omitted.

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 w…

Using the batteries is emissions free. Claiming anything else is just bringing emotional baggage and irrationality to the situation.

It is anything but. It's like saying "gasoline is emissions free, it's the burning of it that's the problem."

If we're going to have a rational discussion about various forms of emission, we need to talk about total fuel cycle emissions, otherwise it's meaningless. Touting one small section of a fuel cycle as emissions free is at best confusing, at worst misleading.

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

#39

Post by lutorm »

nardi wrote: post #12

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.

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.

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

#40

Post by kazinator »

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.

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