4 ms·

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?

yomly 5y ago
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
- alisonkisk 5y ago
  > 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.
  - deleted 5y ago
    [deleted]
  - p1mrx 5y ago
    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.
- deleted 5y ago
  [deleted]
theelous3 5y ago
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.
ecpottinger 5y ago
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.
- jeffbee 5y ago
  > 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.
  - alisonkisk 5y ago
    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-dioxide-back-into-fuel/ https://www.scientificamerican.com/article/turning-carbon-di... The only reason it's not done is because already made gasoline is cheaper.
    - jeffbee 5y ago
      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.
- GordonS 5y ago
  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.
eloff 5y ago
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.)
- pfdietz 5y ago
  Lithium ion batteries don't contain lithium metal. The lithium is always in the +1 oxidation state.
  - eloff 5y ago
    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.
    - coryrc 5y ago
      Aluminum is a metal but we don't consider ceramic (aluminum oxide) to be a metal.
    - samatman 5y ago
      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.
    - kragen 5y ago
      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.
    - pfdietz 5y ago
      If any form of lithium is a metal, then the phrase you used, "lithium metal", is redundant. Why not just say "lithium"?
LeifCarrotson 5y ago
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.
- samatman 5y ago
  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.
jillesvangurp 5y ago
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.
- MaxBarraclough 5y ago
  > 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?
  - saltcured 5y ago
    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.
    - alisonkisk 5y ago
      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
      - saltcured 5y ago
        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.
cptskippy 5y ago
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.
generalizations 5y ago
That would only be the case if the batteries were nuclear.

yomly 5y ago

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

alisonkisk 5y ago
> 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.
- deleted 5y ago
  [deleted]
- p1mrx 5y ago
  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.
deleted 5y ago
[deleted]

theelous3 5y ago

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.

ecpottinger 5y ago

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.

jeffbee 5y ago
> 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.
- alisonkisk 5y ago
  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-dioxide-back-into-fuel/ https://www.scientificamerican.com/article/turning-carbon-di... The only reason it's not done is because already made gasoline is cheaper.
  - jeffbee 5y ago
    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.
GordonS 5y ago
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.

eloff 5y ago

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.)

pfdietz 5y ago
Lithium ion batteries don't contain lithium metal. The lithium is always in the +1 oxidation state.
- eloff 5y ago
  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.
  - coryrc 5y ago
    Aluminum is a metal but we don't consider ceramic (aluminum oxide) to be a metal.
  - samatman 5y ago
    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.
  - kragen 5y ago
    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.
  - pfdietz 5y ago
    If any form of lithium is a metal, then the phrase you used, "lithium metal", is redundant. Why not just say "lithium"?

LeifCarrotson 5y ago

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.

samatman 5y ago
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.

jillesvangurp 5y ago

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.

MaxBarraclough 5y ago
> 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?
- saltcured 5y ago
  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.
  - alisonkisk 5y ago
    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
    - saltcured 5y ago
      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.

cptskippy 5y ago

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.

generalizations 5y ago

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