the problem is rather to automate this and upscale this and I'm not sure how safe this method is. generally speaking if the EU makes battery recycling mandatory it definitely would benefit from a method where you don't have to grind the battery. I see this more as a PoC which can be further explored
Oldschool lead-acid batteries need not be destroyed to be recycled. They can, and are, easily disassembled and refurbished. For all the lithium hype, lead-acid remains a valid option for non-mobile applications where storage density is not relevant.
Where can I get cheap recycled lead acid batteries?
I like them more the li-ion because they’re more forgiving to temperature changes and have a much lower chance of catching on fire
The recycling process isn’t direct battery-to-battery. The lead from old batteries is removed, purified, dried into ingots, then sold back to battery manufacturers to make new batteries. In other words, it’s likely that every lead acid battery you buy is made from recycled batteries.
The process of dying and rejuvenation would be somewhat analogous chemically.
In this case the electrode is metallic lead and the electrolyte is water containing sulfuric acid.
The electrode-electrolyte "interphase" is a solid coating based on lead sulfate, that forms on the lead plates after extended recharge cycles. This doesn't redissolve very well during use after a while when the electrolyte has become oversaturated with lead ions, and the electrodes have been "replated" so many times. Especially when recharged from near-death.
One antique way of restoration without disassembly was to agitate the battery using an industrial vibrator to loosen up the solids, then dump out the (highly toxic lead-containing) electrolyte to physically remove as much sludge as possible. Followed by repeated filling using distilled water, agitation, and dumping until the waste water looks OK. One final fill with DI water (which acts as a very weak electrolyte at this point) and a reverse charge until an amp or two has been reached for a bit, to deplate as much oxidized coating as possible into a virgin solvent.
More agitation, dumping, rinsing, and finally replace with fresh acid.
Desperate measures for desperate times, not too economical today unless similar wastewater is already being handled in a scale that dwarfs a single battery, and fresh acid is obtained surplus or purchased at bulk pricing as well.
This sounds more complicated than the existing processes to recycle the acid and the electrodes separately and make new batteries from the raw materials.
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