Battery breakthroughs

Discussion in 'General' started by Domenick, Oct 7, 2017.

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  1. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    (a) I was making an analogy between a frozen battery pack and a depleted pack of ultracapacitors. I thought that was obvious; my apologies if it wasn't. As with nearly all analogies, it's not perfect.

    (b) Actually, since very cold batteries have lower capacity, some of the charge may be lost, if the batteries are fully charged. But certainly not all of the charge is lost.
     
    Last edited: Feb 18, 2018
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  3. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    [​IMG]

    No. Just no.

    But we have certainly identified the reason you believe that there is some magic way to change the basic physical/chemical properties of hydrogen, as well as why you believe that no further improvements in batteries are possible.

    Yes, and you've just given an excellent example. Congratulations!

    P.S. -- You might want to look up the definition of "exothermic".
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    Last edited: Feb 18, 2018
  4. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    But if you're going to completely replace the battery pack with a pack of ultracapacitors, then you'd have to cover the full 70 seconds... well not actually the full output for that 70 seconds, but the full difference in the output from the fuel cell stack over that 70 seconds. Every time you bring a FCEV to a stop, it's going to power down the fuel cell stack. Now that probably doesn't mean to exactly zero output every time you bring the car to a stop at a stop light, because the car still needs some auxiliary power so long as it's not turned off. But it's probably going to be operating at only a few percent of full power when "idling".

    Anyway, 100 kW is about what you'd need to power a compact car when accelerating strongly, and you'd certainly need more than 10 seconds of power, to handle accelerating up to highway speed from a stop, and maintaining that speed, until the fuel cell stack can be powered up to fully handle the load. If it's a bigger car, then you'll need even more.
     
  5. Martin Williams

    Martin Williams Active Member

    Perhaps I have overestimated your knowledge. If so, I apologise.

    Combining hydrogen and nitrogen results in heat being generated (think of it as burning hydrogen in nitrogen) This is known as an exothermic reaction (it results in heat). Now heat will dissociate ammonia back into hydrogen and nitrogen, so if the reaction vessel is allowed to run hot, the reaction is slower as the ammonia produced gets promptly dissociated back into its component parts. Cooling it means you get quicker conversion.

    Let me know if you are still baffled. I'd like to help if possible.
     
  6. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    You troll quite well. I suppose everyone has something they do well.

    For you, science quite obviously ain't it. Your claim that you can "burn" hydrogen without any oxygen present is another perfect example of how you need a remedial grade-school course in introductory science. I can't even laugh at it; it's too sad for that.

    Some reactions have an equilibrium temperature, which means the reaction slows when it approaches or reaches that equilibrium.

    But you have confused the true concept that adding external heat to such reactions actually slows them, because they more closely approach equilibrium, with the false concept that artificially cooling them will actually speed up the reaction.

    Clearly thermodynamics, and the flow of energy, are concepts you fail to grasp.

    Reminds me of a famous poem:

    A Little Learning
    by Alexander Pope

    A little learning is a dangerous thing ;
    Drink deep, or taste not the Pierian spring :
    There shallow draughts intoxicate the brain,
    And drinking largely sobers us again.
    Fired at first sight with what the Muse imparts,
    In fearless youth we tempt the heights of Arts ;
    While from the bounded level of our mind
    Short views we take, nor see the lengths behind,
    But, more advanced, behold with strange surprise
    New distant scenes of endless science rise !
    So pleased at first the towering Alps we try,
    Mount o’er the vales, and seem to tread the sky ;
    The eternal snows appear already past,
    And the first clouds and mountains seem the last ;
    But those attained, we tremble to survey
    The growing labours of the lengthened way ;
    The increasing prospect tires our wandering eyes,
    Hill peep o’er hills, and Alps on Alps arise !
     
    Last edited: Feb 19, 2018
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  8. Martin Williams

    Martin Williams Active Member

    I actually am a scientist. I am by training a physicist but earned a living as an electronics engineer before moving on to mathematics. I have actually done work on solving differential equations describing an industrial chemical reaction similar to the one I offered as a simple example.

    Believe me. I know what I am talking about.

    People can decide for themselves whether 'science is not for me' or not. And of course, they can do the same for you.
     
  9. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    Then you ought to be able to understand why the Laws of Thermodynamics will forever prevent hydrogen from being used as a primary fuel for transportation. You ought to have understood that before anyone here explained it to you. Yet you keep showing yourself to be a science denier by rejecting that reality.

    And you ought to understand why it's science-made-stupid to claim that a chemical process for making ammonia somehow refutes the reality that the chemical reaction in a fuel cell stack runs slower at sub-freezing temperatures.

    Your claims aren't even self-consistent, Martin; let alone true!
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  10. Martin Williams

    Martin Williams Active Member

    It is because I am a scientist that I know hydrogen CAN be used for this. Nor am I alone in this belief. A great deal of work has been done and is continuing to be done on hydrogen for transport as proved by the motor companies who are now beginning to produce workable vehicles. Many city buses are running on hydrogen already and they have proved practical and durable.

    Too early to be certain of course, at the moment but the one that is now available in parts of your country has been well received. It will be joined by others soon at lower cost which will give us a better idea of how popular they will be.

    And I am perfectly capable of pointing out - with a counterexample - that your rather wild claim that ALL chemical reactions go faster with heat is false. Any connection of this to a conclusion about fuel cells was made by you not me, and I have nothing to add to it.

    A sober assessment of progress made and where Fuel Cell Technology is now can be seen here:

    https://energy.gov/eere/fuelcells/fuel-cell-technologies-office-accomplishments-and-progress
     
  11. Can we consider this conversation about hydrogen between you two to be at an impasse now?

    Let's allow this thread to return to its previously scheduled battery breakthrough topic.
    Thanks! ;)
     
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  13. Martin Williams

    Martin Williams Active Member

    Fine by me. Has there been a breakthough whilst we were arguing?
     
  14. I want put the batteries on a cooled chamber, in constant 21º C temperature - this can extend its lifespan ?
     
  15. If you can somehow keep the interior of a battery pack at 21º C, it should last longer than one exposed to high temperatures for long periods. I imagine, though, it would be quite an engineering job.
     
  16. Martin Williams

    Martin Williams Active Member

    You are also sacrificing range to do so, Ruisvensson. Heating or cooling requires energy which can only come from the battery and increases the weight of the vehicle. Obviously, you would consider insulation, but as the batteries themselves get warm in charge and heavy discharge this can leave you worse off under certain circumstances. It also means extra bulk. How much range all this costs depends on the overall design of the vehicle.

    You would need to do quite detailed mathematical modelling to establish what needs to be done for an optimal solution I think.
     
  17. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    Not sure what you mean. If you mean long-term storage of batteries, the Battery University website says:

    The recommended storage temperature for most batteries is 15°C (59°F)...
    If you mean you want to use a working lithium ion battery pack with no built-in cooling system, and you will put it in a storage space with a constant 21º C temperature, then that will help a little with battery life, yes. What really kills li-ion battery life either is letting the pack get hot and staying hot for 24 hours or more, or charging the pack in high humidity when it's hot.

    But unless you have a way of preventing heat from building up deep inside the pack, then just keeping the space it's in at 21º C will be of limited usefulness.

    Some questions for you:

    1. Are you talking about lithium ion batteries, or some other type?

    2. How tightly packed will the batteries be inside the space? Will there be some room between the batteries, to allow air flow?

    3. Will there be a fan inside the space for constant air circulation?

    4. What will the battery pack be used to power?

    5. How heavily will the pack be used? Will it be called upon for high power use, or will it be subjected to DCFC (Direct Current Fast Charging), either of which will cause the pack to heat up quite a bit?
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  18. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    So, does this mean you will not be using the battery pack to propel the motor home, but rather you'll be using it as backup for a solar power installation to run the electrical power in the motor home when it's parked?

    If so, then you shouldn't worry about the pack overheating, unless it's in a chamber with no ventilation, which might let heat build up inside.
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  19. terminaltrip421

    terminaltrip421 New Member

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  20. Martin Williams

    Martin Williams Active Member

    This has been discussed here on another thread Terminaltrip421. It is only a breakthrough if it doesn't degrade other parameters equally essential to a good battery such as lifetime, energy density, cost etc.

    As ever, announcements of these 'breakthroughs' omit such details. As they rarely if ever make it to production one assumes that most of them DO have such downsides. We will have to wait and see in this case.

    It should be remembered that published papers are generally optimistic in tone in the hope that this may encourage further funding.
     
  21. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    Well, if this thread is going to be restricted to advanced in li-ion (or other types of EV batteries) tech which actually gets commercialized, then it's going to be a pretty lonely discussion!

    I've been following the breathless and mostly uncritical news coverage we see of announced battery breakthroughs ever since I joined the (now defunt) TheEESTory forum, and that was back in 2008. In all that time, with an average I'd estimate at about two announcements per month, there has been exactly one announcement which eventually did make it into production and into actual EVs, and that was LG Chem's announcement of what they mis-named a "200 mile" battery... which merely meant a sudden drop in cost of li-ion EV batteries.

    Now, that's not to say that we won't eventually get another significant breakthrough. After essentially no progress in the field from circa 1885 to the 1960s, battery tech has advanced in the form of NiCad, NiMH, lithium ion, and lithium ion polymer types. Over the past several years there have been only incremental improvements in li-ion batteries made on an industrial scale.

    However, anyone who thinks we'll never see another significant breakthrough is ignoring reality pretty firmly. Many companies are working on putting solid state batteries into production, and it's only a matter of time until one or another actually does so.
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  22. Researchers discover why adding carbon to new type of solid electrolyte improves diffusion

    Don't here much about the specific challenges in solid state battery development, so I found this interesting. Basically, to aid the flow of lithium ions through the solid electrolyte, they've added some carbon. In scientific speak, it's explained thusly:

    "The addition of carbon to the closo-borate anion creates what’s known as a dipole, which repels lithium in the local vicinity of the carbon atom. As the anion spins, the carbon atom faces different directions, each time forcing lithium to move away to a nearby site in the solid matrix. Because the salt is full of spinning anions, this results in very rapid motion of lithium."
     
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