7 ms·

Lower-cost sodium-ion batteries are finally having their moment

14 points by givinguflac 2y ago

Syonyk 2y ago
They seem (both the article and the press release) to conspicuously avoid mentioning any details about important open problem with sodium-ion: Cycle life/longevity. > On November 22, China’s Huawei announced a new patent for sodium-ion batteries named “Electrolyte Additives and Preparation Methods, Electrolytes and Sodium-ion Batteries.” The company’s latest work has focused on improving the shortcomings of sodium batteries – such as low coulombic efficiency and poor cycle life – by optimizing the electrolyte formula. Yes, you've "improved the shortcoming." By how much? The lack of numbers is concerning. Sodium ion has been in the labs for a while, but at least as of last I saw, they weren't managing more than a couple hundred cycles to 80% capacity. Lithium-ion is now typically thousands of cycles to 80% capacity (and associated higher internal resistance - 80% is just the standard benchmark for "lifespan" given the range of issues you see by that capacity loss). That they're "fluffy" batteries in terms of density isn't a huge problem for a lot of cases, but that their cycle life is "a few hundred cycles" has been a serious issue for any significant application of them. That they don't mention this in the slightest implies, rather strongly, that they've not fixed that particular problem with it... For a 70kWh battery pack, 300 cycles at 3 mi/kWh (a midrange average for year round driving) gets you 21MWh cycled through the pack, or 63k miles. Not exactly a stellar lifespan for a car battery pack. That same pack at a lithium-ion standard 1500 cycles gets you about 315k miles.
- DennisP 2y ago
  Wikipedia's page on sodium-ion lists several commercially-available batteries capable of several thousand cycles. https://en.wikipedia.org/wiki/Sodium-ion_battery https://en.wikipedia.org/wiki/Sodium-ion_battery
  - Syonyk 2y ago
    It does. Can you find any independent confirmation of those claims? I generally regard battery spec sheets as "wishful thinking," based on having done a lot of work with lithium chemistries in the past. Some of them are counting "cycle life" at 80% Depth of Discharge, which... kind of "isn't how that measurement is done."
    - DennisP 2y ago
      I don't have any special sources, but since sodium-ion batteries are already being installed in BEVs and power grids, I guess we'll all find out how it's going before long. No reason a power grid can't restrict their battery storage to 80% discharge, if necessary. It just means buying 20% more battery.
- toomuchtodo 2y ago
  https://www.energy-storage.news/first-half-world-largest-200mwh-sodium-ion-project-comes-online-china/ https://www.energy-storage.news/first-half-world-largest-200...
- torginus 2y ago
  Afaik, an important component of battery degradadation is the deformation of the anode and cathode as ions migrate between the two electrodes. Sodium ions are much larger that Lithium so this issue is much more pronounced. So in addition to energy/mass, there is another metric that prevents them from catching up to Lithium.
DennisP 2y ago
For a long time after reading "A Nation-Sized Battery"[1] I thought there was no way we could run a grid on wind/solar/battery without plenty of hydro/geothermal/nuclear for the windless nights, just due to the raw material requirement of that much battery. Cheap batteries from earth-abundant materials change that completely. Iron-air is another possibility, though I think it's less efficient. [1] https://dothemath.ucsd.edu/2011/08/nation-sized-battery/ https://dothemath.ucsd.edu/2011/08/nation-sized-battery/
- credit_guy 2y ago
  > Cheap batteries from earth-abundant materials change that completely. Not really. Batteries need to be about 100 times cheaper than current ones to make a difference. The way to think is this: how many cycles do you need to recoup the cost of the battery? Let's say you get electricity in the summer for roughly zero cents per kWh, and sell in the winter at 50 cents, and you incur zero losses. Current battery prices are above $100 per kWh, so you need at least 200 cycles to break even. At one cycle per year, that's 200 years. If, however, you charge during the day and sell at night, you can break even fairly quickly, even if the profit per cycle is just a few cents per kWh. So, current batteries are ok for daily charge-discharge cycles. But not for yearly ones, and no battery will be for the foreseeable future, because the cost needs to go down by a factor of 100, at least.
  - dash2 2y ago
    How many years did it take for them to drop by the previous factor of 100?
    - bsder 2y ago
      Erm, never a factor of 100. Lithium battery prices dropped from about $700-ish per kWH to about $140 or so. About 1/5 in 10 years and most of the drop was early (about a factor of 1/3 from 2013 to 2016). Lithium battery prices will continue to drop, but the big gains are over. It's now going to be a slow industrial production decrease over time.
rzwitserloot 2y ago
I'm glad sodium is having its day in this configuration of using them in batteries. What I'm really trying to understand is how in the blazes we aren't using Sodium _directly_ as energy transport mechanism. Using the Castner Process ( https://en.wikipedia.org/wiki/Castner_process https://en.wikipedia.org/wiki/Castner_process ) you run the process of (caustic soda + energy) -> (water, oxygen, pure Sodium). This process is 'perfect' in that you don't get contaminants; you lose nothing in this reaction. (It's decidedly imperfect in that the reverse reaction occurs during, so H2 wafts off, and it needs ~330ºC to run). This process has been done to death in the early 1900s, but humanity hasn't done this stuff for a 100 years since the invention of a different process that turns NaCl into Sodium and Chlorine gas, because the latter is _also_ valuable, whereas water aint. It's... perfect. You ship caustic soda which is relative to other energy processes and carriers not all that dangerous (you don't need to store it pressured for example), cheap, extremely abundant to the desert, there you have a massive solar farm that turns into pure clean water and pure Sodium. That's even better than a hypothetical amazing Electrolyzer, because you _need_ water with those, whereas castner _makes_ water. I hear they can use that in the desert. Oh, and the anodes can be made from iron, which is cheap, easy, and abundant. Unlike the material you need to make your anodes from in state of the art water-to-H2 electrolysers! Ship the sodium back. All you need is clean water. Toss a bucket of water at it and it poofs back into (Heat + H2 + caustic soda). Again, __perfectly__, no losses. You don't need a reactor or a catalyst or pressure; that process just goes automatically, all you need is a bucket and a vessel. Storing sodium is, despite the youtube movies, easy. Some paper steeped in oil is all you need to wrap it in. It's stable under all 'warehouse temperatures' (-10 to +70), does not need pressure, and __has zero losses during storage__. It's also quite light. Some back of the envelope math says that it's energy dense enough; a containership full of sodium contains more than enough energy to pay for the trip and then some - about as much H2 you can make with that as a ship with pressurized H2. I'm guessing I must have messed up that math because this feels like it solves.. everything. Free energy for all. There's enough Sodium the world over, you can start right now (Sodium is already made in industrial quantities for other purposes, so you can just buy a containership's worth right away). Surely after 100 years of science we can improve on the already functional Castner Process. Solar panels are idiotically cheap and plentiful. You can convert half the sahara, or the entire east coast of Spain, or the sun belt, into a giant solar farm, just ship coastic soda to it and sodium out. More energy than you'll ever need, and you solved the availability problem because you can store it, at no loss at all, effectively forever, at nearly no cost. Any warehouse can be converted into storage for peanuts. I'd love to know what I'm missing here.
fs_tab 2y ago
Sodium has a gravimetric energy density of ~4 kWh/kg for complete oxidation (lithium has ~12 kWh/kg and gasoline has ~13 kWh/kg), so there's still plenty of room for improvement. Dr. Shirley Meng has done some interesting work on anode-free solid state sodium ion batteries - current samples have 350 kWh/kg of gravimetric density, but only retain 70% capacity after 400 cycles.
- fs_tab 2y ago
  (typo in previous comment: current samples store 350 Wh/kg)
readthenotes1 2y ago
Another Better Battery Bulletin. Nothing to see here, time to move on. “We tend to be skeptical of news releases from companies,” he said. He specified that his comment applies to all battery companies." -Venkat Srinivasan
- DennisP 2y ago
  Despite everybody's cynicism, batteries have gotten a lot better over the past three decades. It just hasn't happened with any sudden drama. No reason it can't happen for sodium batteries, just as it has for lithium.

14 points by givinguflac 2y ago

They seem (both the article and the press release) to conspicuously avoid mentioning any details about important open problem with sodium-ion: Cycle life/longevity. > On November 22, China’s Huawei announced a new patent for sodium-ion batteries named “Electrolyte Additives and Preparation Methods, Electrolytes and Sodium-ion Batteries.” The company’s latest work has focused on improving the shortcomings of sodium batteries – such as low coulombic efficiency and poor cycle life – by optimizing the electrolyte formula. Yes, you've "improved the shortcoming." By how much? The lack of numbers is concerning. Sodium ion has been in the labs for a while, but at least as of last I saw, they weren't managing more than a couple hundred cycles to 80% capacity. Lithium-ion is now typically thousands of cycles to 80% capacity (and associated higher internal resistance - 80% is just the standard benchmark for "lifespan" given the range of issues you see by that capacity loss). That they're "fluffy" batteries in terms of density isn't a huge problem for a lot of cases, but that their cycle life is "a few hundred cycles" has been a serious issue for any significant application of them. That they don't mention this in the slightest implies, rather strongly, that they've not fixed that particular problem with it... For a 70kWh battery pack, 300 cycles at 3 mi/kWh (a midrange average for year round driving) gets you 21MWh cycled through the pack, or 63k miles. Not exactly a stellar lifespan for a car battery pack. That same pack at a lithium-ion standard 1500 cycles gets you about 315k miles.

DennisP 2y ago
Wikipedia's page on sodium-ion lists several commercially-available batteries capable of several thousand cycles. https://en.wikipedia.org/wiki/Sodium-ion_battery https://en.wikipedia.org/wiki/Sodium-ion_battery
- Syonyk 2y ago
  It does. Can you find any independent confirmation of those claims? I generally regard battery spec sheets as "wishful thinking," based on having done a lot of work with lithium chemistries in the past. Some of them are counting "cycle life" at 80% Depth of Discharge, which... kind of "isn't how that measurement is done."
  - DennisP 2y ago
    I don't have any special sources, but since sodium-ion batteries are already being installed in BEVs and power grids, I guess we'll all find out how it's going before long. No reason a power grid can't restrict their battery storage to 80% discharge, if necessary. It just means buying 20% more battery.
toomuchtodo 2y ago
https://www.energy-storage.news/first-half-world-largest-200mwh-sodium-ion-project-comes-online-china/ https://www.energy-storage.news/first-half-world-largest-200...
torginus 2y ago
Afaik, an important component of battery degradadation is the deformation of the anode and cathode as ions migrate between the two electrodes. Sodium ions are much larger that Lithium so this issue is much more pronounced. So in addition to energy/mass, there is another metric that prevents them from catching up to Lithium.

DennisP 2y ago

For a long time after reading "A Nation-Sized Battery"[1] I thought there was no way we could run a grid on wind/solar/battery without plenty of hydro/geothermal/nuclear for the windless nights, just due to the raw material requirement of that much battery. Cheap batteries from earth-abundant materials change that completely. Iron-air is another possibility, though I think it's less efficient. [1] https://dothemath.ucsd.edu/2011/08/nation-sized-battery/ https://dothemath.ucsd.edu/2011/08/nation-sized-battery/

credit_guy 2y ago
> Cheap batteries from earth-abundant materials change that completely. Not really. Batteries need to be about 100 times cheaper than current ones to make a difference. The way to think is this: how many cycles do you need to recoup the cost of the battery? Let's say you get electricity in the summer for roughly zero cents per kWh, and sell in the winter at 50 cents, and you incur zero losses. Current battery prices are above $100 per kWh, so you need at least 200 cycles to break even. At one cycle per year, that's 200 years. If, however, you charge during the day and sell at night, you can break even fairly quickly, even if the profit per cycle is just a few cents per kWh. So, current batteries are ok for daily charge-discharge cycles. But not for yearly ones, and no battery will be for the foreseeable future, because the cost needs to go down by a factor of 100, at least.
- dash2 2y ago
  How many years did it take for them to drop by the previous factor of 100?
  - bsder 2y ago
    Erm, never a factor of 100. Lithium battery prices dropped from about $700-ish per kWH to about $140 or so. About 1/5 in 10 years and most of the drop was early (about a factor of 1/3 from 2013 to 2016). Lithium battery prices will continue to drop, but the big gains are over. It's now going to be a slow industrial production decrease over time.

rzwitserloot 2y ago

I'm glad sodium is having its day in this configuration of using them in batteries. What I'm really trying to understand is how in the blazes we aren't using Sodium _directly_ as energy transport mechanism. Using the Castner Process ( https://en.wikipedia.org/wiki/Castner_process https://en.wikipedia.org/wiki/Castner_process ) you run the process of (caustic soda + energy) -> (water, oxygen, pure Sodium). This process is 'perfect' in that you don't get contaminants; you lose nothing in this reaction. (It's decidedly imperfect in that the reverse reaction occurs during, so H2 wafts off, and it needs ~330ºC to run). This process has been done to death in the early 1900s, but humanity hasn't done this stuff for a 100 years since the invention of a different process that turns NaCl into Sodium and Chlorine gas, because the latter is _also_ valuable, whereas water aint. It's... perfect. You ship caustic soda which is relative to other energy processes and carriers not all that dangerous (you don't need to store it pressured for example), cheap, extremely abundant to the desert, there you have a massive solar farm that turns into pure clean water and pure Sodium. That's even better than a hypothetical amazing Electrolyzer, because you _need_ water with those, whereas castner _makes_ water. I hear they can use that in the desert. Oh, and the anodes can be made from iron, which is cheap, easy, and abundant. Unlike the material you need to make your anodes from in state of the art water-to-H2 electrolysers! Ship the sodium back. All you need is clean water. Toss a bucket of water at it and it poofs back into (Heat + H2 + caustic soda). Again, __perfectly__, no losses. You don't need a reactor or a catalyst or pressure; that process just goes automatically, all you need is a bucket and a vessel. Storing sodium is, despite the youtube movies, easy. Some paper steeped in oil is all you need to wrap it in. It's stable under all 'warehouse temperatures' (-10 to +70), does not need pressure, and __has zero losses during storage__. It's also quite light. Some back of the envelope math says that it's energy dense enough; a containership full of sodium contains more than enough energy to pay for the trip and then some - about as much H2 you can make with that as a ship with pressurized H2. I'm guessing I must have messed up that math because this feels like it solves.. everything. Free energy for all. There's enough Sodium the world over, you can start right now (Sodium is already made in industrial quantities for other purposes, so you can just buy a containership's worth right away). Surely after 100 years of science we can improve on the already functional Castner Process. Solar panels are idiotically cheap and plentiful. You can convert half the sahara, or the entire east coast of Spain, or the sun belt, into a giant solar farm, just ship coastic soda to it and sodium out. More energy than you'll ever need, and you solved the availability problem because you can store it, at no loss at all, effectively forever, at nearly no cost. Any warehouse can be converted into storage for peanuts. I'd love to know what I'm missing here.

fs_tab 2y ago

Sodium has a gravimetric energy density of ~4 kWh/kg for complete oxidation (lithium has ~12 kWh/kg and gasoline has ~13 kWh/kg), so there's still plenty of room for improvement. Dr. Shirley Meng has done some interesting work on anode-free solid state sodium ion batteries - current samples have 350 kWh/kg of gravimetric density, but only retain 70% capacity after 400 cycles.

fs_tab 2y ago
(typo in previous comment: current samples store 350 Wh/kg)

readthenotes1 2y ago

Another Better Battery Bulletin. Nothing to see here, time to move on. “We tend to be skeptical of news releases from companies,” he said. He specified that his comment applies to all battery companies." -Venkat Srinivasan

DennisP 2y ago
Despite everybody's cynicism, batteries have gotten a lot better over the past three decades. It just hasn't happened with any sudden drama. No reason it can't happen for sodium batteries, just as it has for lithium.