[HN Gopher] Battery parts can be recycled without crushing or me...
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Battery parts can be recycled without crushing or melting
Author : giuliomagnifico
Score : 59 points
Date : 2021-04-29 14:27 UTC (8 hours ago)
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| Syonyk wrote:
| Interesting, but probably "of limited use to useless" long term,
| because batteries don't come apart nicely without, at a minimum,
| high risks of shorting them out and thermal runaways.
|
| For the typical cylindrical cells, the "jelly roll" is squeezed
| in quite tightly (this reduces internal resistance by squeezing
| the bits tightly together and optimizes capacity per cell), and
| then the bits tend to swell a bit in use. This is one of the
| advantages of a cylindrical cell - those stresses turn into
| tension stresses around the circumference and the cell doesn't
| actually swell like prismatic cells.
|
| But getting the bits out, intact, without shorting something out?
| Good luck.
|
| https://doi.org/10.1002/cssc.202100629 is the link to the
| article, but I don't have access without paying. If anyone finds
| it, I'd love to read it to see what they've done, though!
| zackees wrote:
| Likely works for larger EV type batteries though..?
| dehrmann wrote:
| > because batteries don't come apart nicely without, at a
| minimum, high risks of shorting them out and thermal runaways.
|
| Is there a way to speed up self-discharge? Or maybe manufacture
| batteries in a way such that they can be easily discharged over
| a ~day, bypassing any circuits limiting the maximum discharge?
|
| The way they're packaged sounds harder to mitigate, though.
| Syonyk wrote:
| Short 'em through a resistor, it's easy enough to fully
| discharge them. You damage them if they're left discharged
| for too long, but for short periods, it might be fine.
| Unfortunately, they also tend to swell when fully discharged.
|
| "Disassembling lithium batteries without destroying them or
| your workshop" is depressingly hard.
| giuliomagnifico wrote:
| I think this technique can applied only on batteries already
| made to be recycled in this way, but is a good pint for the
| future industries "By reusing the structures of batteries we
| can avoid a lot of the labour that is common in recycling and
| potentially save energy at the same time. We believe that the
| method could help companies that are developing industrial
| recycling," Kallio says.
| londons_explore wrote:
| Why not just grind them up in a vacuum chamber?
|
| Both cheap and fireproof. The vacuum pump will collect all the
| electrolyte, nearly ready to directly reuse.
|
| Without electrolyte, the ground up batteries aren't very
| flammable or dangerous.
|
| The rest you can chuck as input into a metal smelter and get back
| as a battery without too much energy invested.
| [deleted]
| amelius wrote:
| Heating things up can be prohibitively expensive.
|
| Otherwise we could simply heat CO2 until it cracks into C and
| O2.
| Syonyk wrote:
| > _Why not just grind them up in a vacuum chamber?_
|
| Because the energy stored in the chemistry of them doesn't care
| about oxygen and will happily come out in a hurry. Look at some
| of the videos of a crushed 18650 - they don't get any oxygen in
| them, but they sure make a nice little firework.
|
| The exothermic runaway is totally oxygen independent, and
| evolves a variety of nasty chemical cocktails out of the
| electrolyte. Those then tend to ignite when they find oxygen,
| creating a blowtorch (but less toxic gasses - pick your poison,
| literally).
|
| If I recall properly some papers I read, about half the energy
| released in a battery runaway is the chemical/electrical
| energy, and the other half is the chemical breakdown and
| electrolyte decomposing/burning. So, if you have a 3.7V nominal
| 100Ah cell, that's 370Wh electrical, and about 740Wh total.
| Dump that in 15 seconds, and you have a nice ~175kW event to
| deal with. In any case, it happens quickly enough to be the
| sort of excitement you want to be upwind of.
|
| But grinding batteries is more challenging than it sounds.
|
| If they're mostly or fully drained, there shouldn't be enough
| energy left to get really exciting, but now you need the labor
| of manually draining each battery before recycling, or you soak
| them in a salt water bath for a while and deal with the
| corrosion (salt water is conductive enough to slowly drain a
| battery without it getting exciting, and it keeps things cool
| enough that if a cell tries to get exciting, it shouldn't be
| able to propagate).
|
| "Replacing parts without having to go through the smelters" is
| what the goal is here, it just requires some things to be true
| about batteries that, to the best of my knowledge, aren't
| broadly true.
|
| Again, I'd love to read the article, though, if anyone has
| access to it.
| londons_explore wrote:
| Put a burning lithium phone battery in a vacuum chamber...
| The battery expands dramatically and the flames go out within
| about 10 seconds...
|
| Just try it.
| virtue3 wrote:
| but then you probably don't have much to recycle if it
| combusts eh?
| Syonyk wrote:
| The flames may go out from lack of oxygen, but that doesn't
| mean that the internal thermal runaway has halted.
|
| There are two processes going on in a flaming lithium
| battery - the internal exothermic runaway, which heats up
| the electrolyte and various other things enough to gas and
| escape, and then the combustion of those gasses in
| atmospheric oxygen.
|
| The vacuum chamber will terminate the flaming combustion
| part, as there isn't any oxygen left to burn the gasses
| with (leaving a rather more toxic cocktail of stuff
| including HF in many cases), but it won't do a thing for
| the internal runaway.
|
| To stop that, you've got two options: Cool the pack
| sufficiently to get everything below the exothermic point,
| or wait for it to run out of stuff to react.
|
| Also, I've no interest in "just trying" lithium pack
| runaways. I've rebuilt a number of lithium packs for people
| over the years, and I've tried very, very hard (and so far
| successfully) to avoid that sort of thing.
| londons_explore wrote:
| The evaporating electrolyte cools the whole thing down
| very quickly. It's icy cold when you get it out.
| Syonyk wrote:
| That's a possible mechanism, hadn't considered that.
|
| However, a brief survey of gasses coming out of a runaway
| still puts it on the list of "Things I have no interest
| in coming near."
| kayodelycaon wrote:
| Lithium ion batteries have oxygen in them. If you add heat,
| they will ignite and you will not be able to put them out until
| you've dumped enough cold water on them to get them below their
| ignition point.
| cbmuser wrote:
| Used nuclear fuel can be recycled by 95%, try to beat that.
| ketralnis wrote:
| Used baseballs can be recycled by 100%, try to beat that.
| dv_dt wrote:
| Lead acid batteries?
| tonyedgecombe wrote:
| Are the most recycled consumer goods, I seem to remember 97%
| are recycled.
| _Microft wrote:
| Well, this might be true but it is irrelevant with regard to
| powering electric vehicles, smartphones or other gadgets.
| elihu wrote:
| Perhaps this could be described as "refurbishing" rather than
| "recycling"?
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