Thread for new battery breakthrough PR releases

Hillhater said:
Maybe not, but using a pack of mixed heritage, pre used, cells is not a risk free situation, and certainly not one an uninformed average user should be exposed to.!
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An uninformed average user could use a cell tester to match cells and end up with a second life for the battery pack.
Back in the days that people fixed things, they did this with hybrid batteries.

I used an iCharger 1010B+ to do it when i was a newbie.
 
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Good thing people have this forum & many others to teach such things :)
 
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One could source old lithium cells. And, test capacity. And, maybe test for internal resistance. However things like dendrites or other mechanical properties are not knowable within a used cell making them a potential fire hazard. I suppose if slow charged and stored in a fire safe container someone could sleep soundly at night.
 
In the case of used lithium-ion cells that mostly show degradation from electrolyte consumption and cathodic/anodic material degradation and not lithium plating, used lithium-ion cells show a tendency of being as safer or safer than new cells:

You peeps should read the paper, there are some rather interesting mechanisms at play.
 
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I'm always curious about mixed chemistry battery packs:

CATL Unveils Freevoy Super Hybrid Battery, Heralding a New Era of Sustainable Travel

On October 24, 2024, CATL launched Freevoy Super Hybrid Battery, the world's first hybrid vehicle battery to achieve a pure electric range of over 400 kilometers and 4C superfast charging, heralding a new era for high-capacity EREV and PHEV batteries. As a transformative solution, Freevoy...
www.catl.com

I still remember reading the initial article thinking that they had managed to make a mixed cathode cell, but alas, it was not it.

CATL made a rather interesting LIB+SIB pack.
 
BlueSwordM said:
In the case of used lithium-ion cells that mostly show degradation from electrolyte consumption and cathodic/anodic material degradation and not, used lithium-ion cells show a tendency of being as safer or safer than new cells:

You peeps should read the paper, there are some rather interesting mechanisms at play.
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Great article indeed!

It's rare that the authors describe in such detail the cell design, choose an optimized charging profile in order to avoid lithium plating and obtain quite a linear discharge capacity decrease. A lot of knowledge.

I would be interested to know how they came up with this specific charging profile... I mean why 0.1C and why starting exactly from 4,1V! Usually 0.1 C is not an end-charge current, at least in the li-ion cell datasheets.

Anyway thanks for sharing!
 
Another day, another analysis article!

Tabless electrode interconnects have slightly higher material costs, but because they allow for higher production rates, total production costs are slightly lower (0.3 euros/kWh):

Hopefully this means every cylindrical cell that we get in the future use tabless electrode designs :)
 
BlueSwordM said:
Another day, another analysis article!

Tabless electrode interconnects have slightly higher material costs, but because they allow for higher production rates, total production costs are slightly lower (0.3 euros/kWh):

Hopefully this means every cylindrical cell that we get in the future use tabless electrode designs :)
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I was wondering if the tabless design affects the specific energy density (particularly volumetric energy density) versus the conventional design?
 
Also the second question is how much % it will be, if it will be within 5% it is probably negligible, but 10% would be significant in HE applications.
 
Pajda said:
I was wondering if the tabless design affects the specific energy density (particularly volumetric energy density) versus the conventional design
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Looking at all the literature, the answer is likely to be negligible.

Why exactly? Well, because with a tabless cell design, you can coat the vast majority of the current collector with active material since it's part of the electrode design itself. That is unlike a tabbed cell design where the tab is added after the whole roll has been coated.

This is also why tabless cell designs (or foil designs for specific cell types) tend to have better cycle life: the more homogeneous electrode area allows for more even degradation, preventing things like swelling and compacting in cylindrical cell designs.

Sources: https://www.bonsaitechnology.it/wp-content/uploads/2023/05/Free-Guide-Tabless-Cylindrical-Cell.pdf

Both are very interested reading exercices when it comes to optimizing interconnects in cylindrical cells.
 
Another day, another very interesting paper:

They used pulsed AC to make it much easier to find plating thresholds for different cells.

It's quite accurate (within 0.1A), but its downside is that for higher power cells, low currents aren't anywhere near as accurate since these cells are built to be much tougher in general. Plating currents are much higher and an AC charging algo will cause reversible plating to happen, making measurements much more difficult to get.

I would heartily recommend reading page 5 and 6 as that's where all the juicy information is located.

Panasonic NCR18650B lithium plating current at -10°C = 0.15A (0.04C charging current maximum before plating happens).
Sony VTC6 lithium plating current at -15°C = 0.8A (0.25C charging current maximum before plating happens).
Sony VTC6 lithium plating current at -20°C = 0.4A (0.12C charging current maximum before plating happens).

On that note, I believe I should stop posting scientific articles(even great ones), unless they're truly groundbreaking and will be implemented commercially. I'll probably make a thread in the next few weeks on the subject.
 
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CamLight said:
Agreed.
Since they cannot be true solid-state cells (not yet) then maybe they are LCO chemistry cells (“LiPo”) with a semi-solid separator setup so they tossed in “solid state“ because it really helps with sales. 🙄
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They're NMC(a) cells.

The one question is: how did they achieve higher energy density with these cells?

We already know pouch cells can achieve slightly gravimetric energy density numbers than aluminium canned cylindrical cells.

So that means they either have more efficient packaging (lean electrolytes can be used to save on electrolyte weight and use more active material, which is easier to do with gelled/solid electrolytes) or higher energy materials.

I'm betting on the former since they're "only" achieving 330Wh/kg, while Nio is using 370Wh/kg cells in their semi solid state packs.

Edit: I have a bad habit of speculating. I'll just stop now. It's just way too much from my end.
 
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BlueSwordM said:
They're NMC(a) cells.
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I always like to remember that any company that says “NMC” in their title along with “Lithium Polymer” and “solid state” may not be a trustworthy source for energy density figures. 🙂 I’m assuming it’s the standard exaggerated spec. But if it’s not there are a few ways the pouch can have good energy density.

BlueSwordM said:
So that means they either have more efficient packaging (lean electrolytes can be used to save on electrolyte weight and use more active material, which is easier to do with gelled/solid electrolytes) or higher energy materials.

I'm betting on the former since they're "only" achieving 330Wh/kg, while Nio is using 370Wh/kg cells in their semi solid state packs.
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I guess all we can do is…umm...guess. 😂
Playing with the anode chemistry and particle engineering can also bump the energy density. But anything done to raise the density also raises the price. These are basic “commodity” cells sold at low cost so my bet is on an exaggerated density spec.
 
So coming back to the "Xingto" pouch batteries, I guess nobody here tested them unfortunately. I am not so sure I wanna be the first to try...
 
Thanks for the vid, that was super interesting.

I'm actually amazed that we can 3D print things that small in the first place w/o creating some kind of structural house of cards.
That new method is crazy.. and sounds like a generational leap.

50-60% off a battery's price is insane using cheap materials.. from a cost perspective.. that's a quick trip to price parity with new ICE vehicles.

I think the next couple years are going to be really exciting for batteries. And also for our hobby!
 
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