6 ms·

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

46 points by happyscrappy 12y ago

partacus 12y ago
How is this a story? Did someone at Stanford open up a grade 10 Chemistry textbook?
- digikata 12y 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."
  - partacus 12y ago
    But it really isn't. The only thing of minor note here is room temperature vs doing it at 60 deg C.
    - damoncali 12y ago
      At scale, that's a good bit of energy, I would assume. But I had the same reaction as you did. "My 7th grade science class did that..."
  - mikexstudios 12y 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 12y 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 12y ago
    You wouldn't actually use a battery. It just makes a neat demo.
- jostmey 12y 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 12y 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.
lutorm 12y 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.
- digikata 12y ago
  See also "hydrogen embrittlement" http://en.wikipedia.org/wiki/Hydrogen_embrittlement http://en.wikipedia.org/wiki/Hydrogen_embrittlement Many materials you might select to carry hydrogen are weakened by it.
- Crito 12y 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.
- nardi 12y 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 12y 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.
  - lutorm 12y ago
sirdogealot 12y 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 12y ago
  For a motor vehicle, you need Energy > Storage > Motor, so Light > Electricity > Electric Motor won't work in this case.
- nardi 12y 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?
  - jacquesm 12y 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.
    - lutorm 12y ago
      We must have had a similar childhood! :-)
- kazinator 12y 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.
nardi 12y 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_duf 12y 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 12y ago
    Using a AAA battery demonstrates that the process can be done using low voltage.
    - alex_duf 12y ago
      ooh, alright, now it makes sense to me. Thanks.
  - kazinator 12y 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.
- mikexstudios 12y 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).
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ChaoticGood 12y ago
Reminds me of Stanley Meyer's invention: http://youtu.be/Vd7QL1-NnlU http://youtu.be/Vd7QL1-NnlU A claim of hydrogen obtained by water splitting fueled car. Very intriguing case of potential pseudo science.
kazinator 12y 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 12y 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 https://www.youtube.com/watch?v=XcIbOkakkDQ

46 points by happyscrappy 12y ago

partacus 12y ago

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

digikata 12y 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."
- partacus 12y ago
  But it really isn't. The only thing of minor note here is room temperature vs doing it at 60 deg C.
  - damoncali 12y ago
    At scale, that's a good bit of energy, I would assume. But I had the same reaction as you did. "My 7th grade science class did that..."
- mikexstudios 12y 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 12y 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 12y ago
  You wouldn't actually use a battery. It just makes a neat demo.
jostmey 12y 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 12y 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.

lutorm 12y 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.

digikata 12y ago
See also "hydrogen embrittlement" http://en.wikipedia.org/wiki/Hydrogen_embrittlement http://en.wikipedia.org/wiki/Hydrogen_embrittlement Many materials you might select to carry hydrogen are weakened by it.
Crito 12y 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.
nardi 12y 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 12y 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.
- lutorm 12y ago

sirdogealot 12y 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 12y ago
For a motor vehicle, you need Energy > Storage > Motor, so Light > Electricity > Electric Motor won't work in this case.
nardi 12y 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?
- jacquesm 12y 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.
  - lutorm 12y ago
    We must have had a similar childhood! :-)
kazinator 12y 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.

nardi 12y 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_duf 12y 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 12y ago
  Using a AAA battery demonstrates that the process can be done using low voltage.
  - alex_duf 12y ago
    ooh, alright, now it makes sense to me. Thanks.
- kazinator 12y 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.
mikexstudios 12y 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).

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ChaoticGood 12y ago

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

kazinator 12y 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 12y 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 https://www.youtube.com/watch?v=XcIbOkakkDQ