Does this prevent lithium - water reaction? Is that fire, or?
When current gen EV batteries catch fire in fresh and saltwater flood waters, is that due to thermal runaway?
(Twisted SWCNT carbon nanotubes don't have these risks at all FWIU)
Generally speaking, thermal runaway is not the lithium reacting directly with water in the air, it's a self oxidizing fire-- The electrolyte fluid is combustable, metal oxides in the anode material release oxygen when heated and a short circuit provides the heat and ignition source.
Good for use cases like vehicles where weight matters.
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> In its announcement, LG Chem has reported that in both battery impact and penetration tests, the batteries equipped with the thermal runaway suppression material either did not catch fire at all or extinguished the flames shortly after they appeared, preventing a full-blown thermal runaway event.
> The material comes in the form of a thin layer, just 1 micrometer (1μm) thick – about one hundredth the thickness of human hair – positioned between the cathode layer and the current collector (an aluminum foil that acts as the electron pathway). When the battery’s temperature rises beyond the normal range, between 90°C and 130°C, the material reacts to the heat, altering its molecular structure and effectively suppressing the flow of current, LG Chem said.
> The material is decribed as highly responsive to temperature, with its electrical resistance increasing by 5,000 ohms (Ω) for every 1°C rise in temperature. The material’s maximum resistance is over 1,000 times higher than at normal temperatures, and it also features reversibility, meaning the resistance decreases and returns to its original state, allowing the current to flow normally again once the temperature drops.
To the best of my searching, a typical lithium ion battery has roughly 20-30 cathode-and-current-conductor layers. So naively this would add less than 50 microns to the battery thickness.
Also, the open-access article is here: https://www.nature.com/articles/s41467-024-52766-9
Would this cause energy losses (inefficiency)?
This, and possibly more importantly: how well does it retain effectiveness under wear/adverse circumstances?
It seems really promising, but if we up the cost of battery production and hence make them more expensive, then it would be nice to know it will still work after extended use.
I dunno. I skimmed the intro of the journal article and they say they achieve
> high conductivity of SRL under standard battery operation
but I don’t know if the losses are truly negligible. I think we need someone who knows more about batteries.
ScholarlyArticle: "Thermal runaway prevention through scalable fabrication of safety reinforced layer in practical Li-ion batteries" (2024) https://www.nature.com/articles/s41467-024-52766-9