Comment by jillesvangurp | Hacker News Reader

Comment by jillesvangurp | Hacker News Reader

Lithium is a valuable resource. EV batteries have lots of it. Therefore EV batteries are valuable even after they stop working.

Lithium is valuable because extracting it from naturally occurring salt deposits is a lot of work. These salt deposits are mostly not Lithium. We are talking trace amounts here. To extract it, you have to process vast amounts of brine. Boil of the water, separate it from other materials, etc. That's a lot of work and energy. Recycling a battery with high concentrations of Lithium is probably a lot less work. For that reason, lithium is a lot more expensive than other materials.

Melting old ice cars to recover the steel is already a thing. The steel has a value. All you need to do is melt it and reuse it. So, we already have existing practices for recycling old vehicles and companies specializing in that. The only thing that changes is that those companies will be dealing with very valuable batteries as well. Lithium is of course quite a bit more lucrative than steel. If it works for steel, it's going to work a lot better for lithium. Because it has a lot more value.

> Lithium is a valuable resource. EV batteries have lots of it. Therefore EV batteries are valuable even after they stop working.

A Tesla battery weighs about 500 kg and has about 10kg of Lithium (2%). The Lithium is worth about $130, whereas the battery costs more than $10,000. It's difficult to extract the trace elements of lithium from the thousands of individual cells honeycombed together in the battery, so there is no known way of getting at that Lithium via processes that are even comparable to the value of the lithium recovered. That's why no one does it.

A car, on the other hand, is 55% steel by weight, and there are relatively straightforward ways of getting that steel (no, the car is not "melted down". The steel components are melted after they are removed from the car). That's why steel in cars is recycled but Lithium in batteries is not.

The issue with recycling is the cost of extraction -- yes, catalytic convertors and old computers contain trace elements like platinum (maybe $2 per catalytic convertor) but extracting it is far too expensive. So merely the presence of an expensive element in a manufactured good does not mean it is economic to extract the element. In the vast majority of situations, it's not.

> yes, catalytic convertors and old computers contain trace elements like platinum (maybe $2 per catalytic convertor) but extracting it is far too expensive.

Catalytic converters can be worth $100s as scrap. They’re regularly stolen from parked cars.

Right, but not for the platinum, which is worth only about $2. Similarly, I'm not saying no that no one will find a way to get scrap value out of a used $10,000 battery, but it's not going to be for the $130 of lithium inside it.

I agree with you on the lithium - it is far too abundant. It seems that most of the value in a catalytic converter is in the palladium and rhodium, though the platinum is worth something too. Catalytic converter chemistries vary a lot too, with some omitting platinum and some omitting palladium.

Globally, the catalytic converter industry uses about 112 tons or platinum, 170 tons of palladium, and 21 tons of rhodium per year. And an individual catalytic converter uses 1-2g for a small car up to 12-15g in a big truck. (Elsewhere I've seen 3-7g as an average for a US catalytic converter.)

https://www.thermofisher.com/content/dam/tfs/ATG/CAD/CAD%20D...

So from what I can tell, an average catalytic converter contains about 5g of PGM's which works out at:

1.85g of platinum at $40/g = $74

2.80g of palladium at $95/g = $361

0.35g of rhodium at $900/g = $315

The Washington post reports that catalytic converter thefts are largely driven by the rhodium they contain (the price of which has gone up enormously because it is a byproduct of platinum mining and platinum itself is not currently worth mining.)

https://www.washingtonpost.com/world/africa/catalytic-conver...

FWIW: the metal components of lithium batteries (especially cobalt) tend to be the economically limiting resources, not the lithium itself. But the point is valid: batteries are indeed harder to recycle than bulk steel, but relative to the cost of extracting new materials recycling is far more effective economically.

Also: it's not like EVs don't have steel chassis. It's (very roughly) the engine block and transmission mass that gets replaced by a battery. Once you remove that battery, the vehicles recycle identically. The only question is about how effective battery recycling is or can be (and it's pretty good already!)

It actually is that many vehicles don't have a steel chassis. The Model Y for instance has an aluminum chassis to save weight. There even other materials such as Carbon Fiber used in some high end vehicle.

The rear underbody of the Y is aluminum but it still has a steel chassis. Aluminum can never fully replace steel because it lacks the strength and rigidity.

Regardless, aluminum is expensive to extract and refine, requiring a tremendous amount of energy. In terms of cost, on average aluminum is more expensive than steel.

> Aluminum can never fully replace steel because it lacks the strength and rigidity.

Huh? The main reason is because Aluminium is expensive. The BWW i3 uses an Aluminium frame exactly because it reduces weight. https://www.marklines.com/en/report_all/Munro003_201710

None of what you said contradicts what you quoted. Steel is a stronger material than aluminum, the trade offs are that it's harder to form and weights more.

The vast majority of current lithium supply comes from hard rock mining, not brines. Brines were about half of lithium supply ten years ago but as the industry took off the amount of hard rock mining in Australia has radically expanded (by 500%).

An EV battery pack does not contain a spectacularly high concentration of lithium. A state-of-the-art battery pack might by 2% lithium. That's higher than subsurface brines, but not miraculously high. Brine mining also throws off lots of valuable products other than lithium. You can get potash, boron, magnesium, and other valuable ores from the same brine, so it can be hard for recycling to compete economically.

Your comment has some nuggets of truth in it.

Ten year ago brines were about all of lithium supply, but now they're about half. The byproducts of lithium extraction from brine are profitable, but not enough to make a big difference to the bottom line of the mining operation.

https://pubs.usgs.gov/periodicals/mcs2021/mcs2021-lithium.pd... from https://www.usgs.gov/centers/nmic/lithium-statistics-and-inf... says that it's about half and half brines and hard-rock mining at this point. Even the expansion in Australia, which is indeed huge, only brings Australia to less than half of the world's lithium supply (40 kilotonnes out of 82 kilotonnes in 02020). All mining outside Australia is from subsurface brines except for one mine in China.

2% is "miraculously high" if subsurface brines are your reference point, because they're usually around 0.05% and almost never as high as 0.2%. It's an orders-of-magnitude difference.

Lithium costs on the order of US$10k per tonne. Potash is about US$800, boron around US$400, and magnesium around US$2000. All of these are mostly extracted from brines.

I had always assumed that when a lithium battery didn't work any more, the lithium was somehow "depleted", or had been charged chemically somehow?

Matter cannot be created nor destroyed. And elemental conversion is a big deal - usually involving nuclear fission or fusion.

Batteries do become depleted but the lithium never disappears, I guess simply put a reverse potential is no longer able to reverse the battery equation back to the energy storing state. Presumably because there is some third reservoir state that a potential cannot reverse (without delving into the chemistry).

Don't be mistaken into thinking that because a charger cannot reverse the battery reaction that the lithium itself is gone, or that there does not exist some completely unrelated process that can recover the lithium - separate from the immediate battery ecosystem

> Matter cannot be created nor destroyed.

It certainly can, E=mc^2. But it's an incredible amount of energy for how much matter you get.

E=mc^2 doesn't really say that matter can be converted to energy, just that energy has mass.

For example, a fission/fusion reaction doesn't make matter go away, but the amount of energy released is large enough to be measured as a loss of mass. When you discharge a battery, it also loses mass, but the amount is too small to notice.

Lithium is lithium. Idk anything about lithium batteries, but presuming they use some kind if lithium salt compound or something, it's going to be a hell of a lot easier to re-saltify it or otherwise rebuild the useful compound, than it is to try and recreate big bang conditions to make more lithium.

Lithium is an element how can it be deleted?

If Lithium is chemically changed what prevents it being chemically changed back?

Batteries are sealed, if material does not leave than all the components used to make it are still inside the battery.

> If Lithium is chemically changed what prevents it being chemically changed back?

Thermodynamics. It is also tremendously difficult to get your gasoline back after you burned it, or to un-cook an egg.

It is not difficult to recover lithium from a battery, but in general do not assume that physical processes are easily reversed.

The energy you get from burning gasoline is about as much as the energy cost of creating it. It's not a complex organism like an egg.

https://www.scientificamerican.com/article/turning-carbon-di...

The only reason it's not done is because already made gasoline is cheaper.

That whole article is about how even with zero-cost energy it would still be double the expense of fossil fuels. Nobody doubts that you can make liquid fuels from solar energy and atmospheric CO2 … that is a plant’s life. The problem is it’s hilariously inefficient.

It's not something I ever gave conscious thought before now, but yes, the depletion assumption sounds a bit silly in retrospect.

If the lithium has changed chemically, presumably the feasibility of changing it back depends on the nature of the change.

Outside of nuclear reactions, elements are not created or destroyed.

What happens in old batteries is the physical structure of the lithium metal is damaged so it does not function as well as a battery, but you can separate out the lithium from the old battery, melt it down and reform it into a new battery (or whatever else you want to do with lithium.)

Lithium ion batteries don't contain lithium metal. The lithium is always in the +1 oxidation state.

To me oxidized metal is a metal, but then that's why I'm not an expert in that field by any stretch of the imagination.

Aluminum is a metal but we don't consider ceramic (aluminum oxide) to be a metal.

Metals are always metals, but they are only metallic in the fully reduced state. So we say "metallic iron" and so on.

So an oxidized metal isn't "a metal" on the macro scale, because it isn't metallic.

You said, "the physical structure of the lithium metal". There is no such physical structure of a bunch of ions floating around in an electrolyte and intercalating themselves into electrodes.

If any form of lithium is a metal, then the phrase you used, "lithium metal", is redundant. Why not just say "lithium"?

Close, the typical problem is that the cation of the lithium compound used in the cathode (LiFePO4, LiCoO2, etc) becomes oxidized or otherwise degraded in a way that the electrochemical reaction can't reverse. In an LiFePO4 battery, you might get some iron oxide. In a traditional lead and sulfuric acid battery, you get lead sulfate crystals. There's typically the exact same amount of lithium present (it doesn't become gaseous and float away) but its constituent elements are unavailable for electrochem.

The most common failure mode is actually dendrites growing off the cathode and puncturing the thin layers of the cylindrical battery. Typically these are cobalt or iron, depending on the chemistry.

Note that I'm discussing failure of a cell, not slow degradation in its ability to hold a charge, which has a variety of causes including the one you sketched out.

The atoms never leave the battery. There is no exhaust. It just works less well because it crystalizes in the wrong form. Which is a process that is trivially reversed.

> a process that is trivially reversed.

If it's trivial, shouldn't lithium recycling have been profitable from the moment we started making lithium batteries?

I think they mean trivial compared to processing raw ore. The general assumption is that you are seeing the normal delay effects or inertia of the economy. Capital is already invested in mining and ore processing. Recycling needs to appear economically worthwhile for a long enough period for investors to grow interested and take the plunge in this new direction.

Processing ore is easier, because you can run tons of ore through an industrial process, and not have to dismantle microscopic pieces of each battery

Note, I am neither a battery nor recycling expert here, but am somewhat interested in dragging unstated arguments to the surface!

I think proponents of this economic view of recycling often argue that you could mechanically shred/grind such post-consumer products into a big mess and think of it as a new type of high-density ore. It might take different refining stages, but they seem to have faith that industrial processing can be invented for these materials and that it ought to be less energy intensive than processing the very low density ores found in nature.

That's what the article says is being done on an industrial scale by pyrometallurgy. Search for "black mass" in the article.

As others have said, matter doesn't change.

As I understand it, lithium crystals form inside the battery and eventually short the battery out.

The lithium moves between the anode and cathode to release/store energy. I think when it's locked up in a crystal it isn't free to move and reduces the battery capacity as well.

That would only be the case if the batteries were nuclear.

"Recycling" lithium batteries is already one of the preferred methods for acquiring lithium by armature chemists.

How does an amateur safely do this? I’ve never heard much about amateur chemists…

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