The really important bit, comparison to lithium ion:
>She did say that large battery banks that might be spun off from this research stand to not only have higher capacity, but also be substantially lighter than lithium ions. Although, she adds, perhaps the greatest weight savings will come not from comparing one battery cell's mass with another. “The biggest difference would be that you don’t have to have the same stainless steel bunkers in each of the cells,” she says.
Not flammable is a big deal in battery tech. We try to pack more and more energy into smaller and smaller cells, so continuing to improve the capacity makes inadvertently releasing all that energy even more dangerous.
Here's another cool project working on that problem with a solid polymer electrolyte. Video shows it continuing to provide power while being sliced into pieces with scissors: https://www.youtube.com/watch?v=m9-cNNYb1Ik
Only if you declare the center as infinitely perfect in every way. If you allow each axis to trade off with the others, then there is no single ideal. Fixed storage would rather have better prices and cycles in exchange for worse density. Mobile devices would rather have better density in exchange for higher prices.
(You can look at it like a path through the solution space. If you keep letting someone pick which attribute to improve, over and over, you eventually hit infinity/infinity/infinity, but different users will take very different paths to get there. At any particular count of improvements, their ideal batteries are significantly different.)
And with regard to kickopotomus's comment, you can get away with a much higher cost if you're targeting the right niche.
Headline is misleading. The battery has a brief burn-in period where it gets better.
> They also published a graph that showed an increase in capacity over more than 300 charge-discharge cycles. (This increase, however, pales in comparison to the cell's at least 23,000-cycle lifespan.)
And once they dig into details, the "apparent increase of entropy" is further exposed as bait. Sounds pretty credible, and not controversial
> She says their glass electrolyte is a ferroelectric material—a material whose polarization switches back and forth in the presence of an outside field. So charge-discharge cycles are effectively jiggling the electrolyte back and forth and perhaps, over time, finding the ideal configuration of each electromagnetic dipole.
> “This is what happens as you are charging and discharging,” Braga says. “You are aligning the ferroelectric dipoles.”
This sounds similar to the concept of self-healing materials. Such materials aren't necessarily at full health (optimal structure) following manufacture, so could expect to see improvements through use.
Some materials and devices also benefit from being broken-in; where properties which impede utility are degraded more rapidly than properties which positively contribute to it.
I thought of concrete vibrators. (probably not the best analogy though)
When people pour concrete they get a certain strength out of it. But if they vibrate it, air and excess water gets removed, and the concrete aligns together to become more cohesive.
> In fact, she adds, up to a point, rising temperatures only increase the electrolyte’s performance.
This is the case for normal lithium-ion batteries as well; they perform better at 120°F than at 70°F (and lose significant performance at even lower temperatures).
I have a LiFEPO4 battery in my motorcycle, and even here in the bay area of California, I notice the change it its cranking ability on colder days. It's a real issue with the chemistry, as attempting to charge it while cold causes some unfavorable reactions as well, so relying on resistive heating to bring it up to temp isn't a great idea.
It is kind of amusing that cranking it a few times until it peters out from lack of charge, waiting for the heat to spread internally, then firing it right up as the capacity recovered due to temperature overcompensates for the previous drain, is a valid thing to do.
For my location, it would be more trouble than it's worth. If I lived somewhere a little colder, though, I think some kind of thermal control would be a real necessity.
As far as I know all ion-exchange (chemical) batteries have a positive temperature coefficient of performance. Lead-acid, NiMH, Alkaline, Lithium-ion, Vanadium flow, etc.
I'm curious, are there types of battery that don't use ion exchange? I'm familiar with physical energy storage using flywheels or compressed air; I suppose you could call something like that a battery if set up to spin a generator.
That's an interesting question. As you say, it depends on definitions.
I would say that some betavoltaic devices would qualify, and perhaps some phase-change stuff that I can't recall right now. Supercapacitors are essentially batteries but I seem to recall they actually do ion exchange as well.
> “The BMS is to control temperatures,” she says. “In our case, we don’t have to have that.” In fact, she adds, up to a point, rising temperatures only increase the electrolyte’s performance.
No need for the stainless steel bunkers to isolate cells. This IS an important breakthrough (if verified).
Probably the only way of releasing the energy fast is to short the battery with a thick wire, or to burn the whole battery with an external source.
There's no rule that having lots of bound up energy has to be dangerous, that it has to be possible to release it quickly. There's enormous amount of potential energy in pure hydrogen gas. If you can just fuse the atoms. But it's incredibly hard to release it.
A quick search shows tnt has 4 kJ / g while paraffin has 42 kJ / g. A lot of energy is in paraffin's hydrocarbon chain, but less energy per bond and it is less accessible.
I would think that it can still short out and overheat, but the material the battery is made of does not combust or have any exothermic chemical reaction. The energetic failure mode would be- "sparks and gets really really hot."
I'll believe it when I can buy a cellphone with one.
Miracle batteries are like Alzheimer's cures and memristor computers: they show promise in the lab but fall down hard when used to develop products people actually use.
> thermodynamics might seem to demand that a battery only deteriorates over many charge-discharge cycles.
Well that's just nonsense.
Any armchair "physicist" claiming that entropy must decrease over time is completely ignoring the fact that the battery is getting energy from an outside source every time it's charged.
A false "entropy of matter natural law" argument used to be forwarded by "evolution debunkers." Richard Dawkins debunked this fake natural law with a thought exercise involving an hourglass with water in one chamber and salt in the other. You can tilt the hourglass to mix the salt and water in one chamber, but if you sit the device in the sun, such that the sun shines on the full chamber, you will eventually see the hourglass return to a state where water is in one chamber and salt is in the other.
Agreed. As far as I remember, the chemical batteries in phones circa 2005 behaved like this: you'd get gradually improving battery life over the first few cycles and then start to experience normal battery deterioration.
So long as nature is paid back its entropy in full it seems to be happy.
I see what you mean (entropy always increases is valid only in a closed system assumption). But didn't you mean "claiming that entropy must increase" instead of "decrease" in your sentence?
>She did say that large battery banks that might be spun off from this research stand to not only have higher capacity, but also be substantially lighter than lithium ions. Although, she adds, perhaps the greatest weight savings will come not from comparing one battery cell's mass with another. “The biggest difference would be that you don’t have to have the same stainless steel bunkers in each of the cells,” she says.
Not flammable is a big deal in battery tech. We try to pack more and more energy into smaller and smaller cells, so continuing to improve the capacity makes inadvertently releasing all that energy even more dangerous.
Here's another cool project working on that problem with a solid polymer electrolyte. Video shows it continuing to provide power while being sliced into pieces with scissors: https://www.youtube.com/watch?v=m9-cNNYb1Ik