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Nickel Hydrogen Batteries by NASA

spectrum.ieee.org

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Re: Nickel Hydrogen Batteries by NASA

#31

Post by jillesvangurp »

dabeeeenster wrote: post #9
jillesvangurp wrote: post #3

Earlier quoted context omitted.

For grid bases storage, energy density does not really matter. What matters is cost and longevity. There are a few emerging battery chemistries that promise to be cheaper and more durable than lithium ion and less vulnerable to hot/cold temperatures as well. The energy density for these is not good enough for things like cars or trucks. But that doesn't matter if the primary application is setting up stationary stora…

EVs do 100% need to get lighter. They are still quite a bit heavier than their ICE equivalents and tyre wear is (IMO) underappreciated as a toxin/pollutant.

There are quite a few lighter EVs. Including some classic car conversions that actually manage to be faster and lighter than their originals. Those cute little EVs that are mass produced in China are far lighter than the super sized trucks people in the US drive. And of course any muscle car burns out its tires, brakes, and has terrible fuel economy.

Re: Nickel Hydrogen Batteries by NASA

#32

Post by onlyrealcuzzo »

VBprogrammer wrote: post #29
onlyrealcuzzo wrote: post #27

Earlier quoted context omitted.

Ah, yes, because trains clearly could not do this and never did in the past. There is no alternative.

Trains have never delivered to individual retail stores, half finished housing estates or petrol stations. Perhaps reserve your sarcasm for when you aren't saying something stupid.

Yes, because none of those things existed before the automobile.

Re: Nickel Hydrogen Batteries by NASA

#33

Post by schiffern »

jsmcgd wrote: post #15

Can anyone comment on the design of the cell, specifically why it is long and thin, which would work against the square cube law. Is a large surface to volume chosen for thermal reasons?

The cells are pressure vessels, so normal cube-square scaling laws don't apply. Instead you need to use pressure vessel scaling laws, which also account for the needed wall thickness.

Pressure vessel scaling laws say that all cylinders have the same mass efficiency, and making long thin cylinders is easier than making short squat cylinders.

Re: Nickel Hydrogen Batteries by NASA

#34

Post by h0l0cube »

HWR_14 wrote: post #22
jsmcgd wrote: post #15

Can anyone comment on the design of the cell, specifically why it is long and thin, which would work against the square cube law. Is a large surface to volume chosen for thermal reasons?

As I understand it, something like a lead-acid battery using volumes of acid and volumes of reactants so a cube gives them more power with the same surface area. NiMH batteries use boundaries between states instead of acid. Therefore, you want long thin batteries of alternating materials to make them more efficient. Or, to put it a different way, NiMH batteries require a large interior surface area, and so the square…

As per the article, these Nickel Hydrogen batteries are very different to NiMH

> Nickel-hydrogen batteries look and work unlike any other battery. They consist of a stack of electrodes inside a pressurized gas tank. The cathode is nickel hydroxide while the anode is hydrogen. When the battery is charging, a catalytic reaction generates hydrogen gas. During discharge, the hydrogen oxidizes and converts back to water.

Re: Nickel Hydrogen Batteries by NASA

#35

Post by VBprogrammer »

onlyrealcuzzo wrote: post #32
VBprogrammer wrote: post #29

Earlier quoted context omitted.

Trains have never delivered to individual retail stores, half finished housing estates or petrol stations. Perhaps reserve your sarcasm for when you aren't saying something stupid.

Yes, because none of those things existed before the automobile.

I'm not even sure what you are trying to say. Perhaps try having a grown up discussion rather than trying to win internet points via your superior sarcastic smack downs.

Retail stores certainly existed before the automobile. People walked, biked or used horses to get to them. Horse and cart were used to deliver things to them.

Re: Nickel Hydrogen Batteries by NASA

#36

Post by jillesvangurp »

jojobas wrote: post #7
jillesvangurp wrote: post #3

Earlier quoted context omitted.

For grid bases storage, energy density does not really matter. What matters is cost and longevity. There are a few emerging battery chemistries that promise to be cheaper and more durable than lithium ion and less vulnerable to hot/cold temperatures as well. The energy density for these is not good enough for things like cars or trucks. But that doesn't matter if the primary application is setting up stationary stora…

Current electric semis are only good for hauling potato chips (i.e. mostly air) for any distance over 100km. Weight is very very valuable on both passenger cars and commercial trucks. Hauling those extra 300-500kg vs a comparable size sedan comes at a steep cost too, as increasing weight requires stronger/wheels body, wheels, brakes, even engines. There is a huge demand for higher energy density, preferably of a non-…

Nonsense. There are battery electric trucks in every vehicle class you can name. 200 tonne road trains in Australia, check. Mining trucks, check. Not a problem. There are also multiple electrical class 8 semi's on the road already. Tesla class 8 semis is a good example. But you can also get similar trucks from e.g. Volvo. Long distances buses, school buses, vans, etc. All available right now.

As cost of the batteries comes down, these things will only become more popular.

Re: Nickel Hydrogen Batteries by NASA

#37

Post by HWR_14 »

h0l0cube wrote: post #34
HWR_14 wrote: post #22

Earlier quoted context omitted.

As I understand it, something like a lead-acid battery using volumes of acid and volumes of reactants so a cube gives them more power with the same surface area. NiMH batteries use boundaries between states instead of acid. Therefore, you want long thin batteries of alternating materials to make them more efficient. Or, to put it a different way, NiMH batteries require a large interior surface area, and so the square…

As per the article, these Nickel Hydrogen batteries are very different to NiMH > Nickel-hydrogen batteries look and work unlike any other battery. They consist of a stack of electrodes inside a pressurized gas tank. The cathode is nickel hydroxide while the anode is hydrogen. When the battery is charging, a catalytic reaction generates hydrogen gas. During discharge, the hydrogen oxidizes and converts back to water.

Sorry, yes. I was, however, describing my understanding of Nickel Hydrogen batteries' relationship with the square-cube law. Not NiMH.

See this diagram: https://en.wikipedia.org/wiki/File:Nickel-hydrogen_battery_N...

Re: Nickel Hydrogen Batteries by NASA

#39

Post by brutusborn »

4death4 wrote: post #28
danw1979 wrote: post #12

This sounds great on paper but there’s a couple of questions left hanging: > We take the battery, put it in an open fire, and watch it continue to heat up. What ends up happening is that the pressure above top charge will force the hydrogen back into water. And then we have a release valve designed into the unit so at a predesigned pressure and temperature that will release, and you’ll get a steam vent.” But what abo…

> But what about the hydrogen? Doesn’t it say the hydrogen is vented as H2O?

I think the parent is assuming that there isn’t conversion. In the same way that electrolysers electrodes also have H20 in addition to O2 and H2.

Re: Nickel Hydrogen Batteries by NASA

#40

Post by pfdietz »

fransje26 wrote: post #10
scott_h wrote: post #2

[dead]

> the battery catalyst is a Nickel-Molybdenum-Cobalt alloy, which seems like a pretty rare, expensive component. So you didn't read the article? The piece states: "Yi Cui’s team found an inexpensive nickel-molybdenum-cobalt alloy catalyst for the battery that costs $20/kg." For a catalyst, that doesn't sound too expensive. > Their published research cites a $~83/kWh cost for just the materials (that's not very cheap)…

The Li-ion number is assuming a current mix of chemistries, not the cheaper one (LFP).
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