7 ms·

A novel solid, rechargeable air battery

59 points by rustoo 3y ago

apienx 3y ago
I personally made similar devices in the lab over a decade ago (and yes, with Nafion and benzoquinones). They're very unstable. I'd file this under gimmick rather than novel tech.
skykooler 3y ago
> While the discharge capacity of SSAB-PDBM reduced to 44% after 30 cycles, by increasing the proton-conductive polymer content of the negative electrode, the researchers could significantly improve it to 78%. That's still a 22% drop in capacity after only 30 charge cycles; this system has a long way to go before becoming a practical battery.
- fbdab103 3y ago
  While probably not ideal for a phone or car, it could still have its uses. So long as it stabilizes at that 70%+ region, that is not potentially a deal-braker for grid installations. Which is an optimization of installation cost, maintenance, longevity, operating temperature/pressure requirements, charge/discharge rates, etc.
  - DennisP 3y ago
    They didn't say it stabilizes, though. You'd think they'd mention that if it did.
  - idontwantthis 3y ago
    If it stabilized then it would just be 30% heavier. I doubt it stabilizes.
- trompetenaccoun 3y ago
  Depends one the cost and environmental impact. I don't know anything about the compounds they used and anyway they're still experimental and could be replaced by others. But in stationary settings where size isn't an issue they can lose substantial capacity upfront and still be viable if they can be cheaply produced and don't involve complicated steps like in lithium mining for example.
  - HPsquared 3y ago
    Flow batteries are better suited for stationary applications, I think. Liquids lend themselves to large-scale processing.
    - Turskarama 3y ago
      Flow batteries are pretty good but I think if the dirt cheap "heavy" chemistries such as liquid metal and iron-air take off then not needing any moving parts and having no risk of leaks is an advantage.
- scandum 3y ago
  > the coulombic efficiency of SSAB-PDBM was 84% at 4 C rate, which gradually decreased to 66% at 101 C rate. Lithium batteries are over 95% efficient, so a long way indeed. Since the battery contains water, I assume it doesn't work below 0 C.
  - elcritch 3y ago
    It's a solid electrolyte battery, not water electrolyte based.
    - pengaru 3y ago
      There's clearly h2o leaving the oxygen positive electrode in the illustration at the top of TFA If the h2o ices up on that side, what happens to the battery? or is it not possible?
  - tzs 3y ago
    I don't think 4 C and 101 C are referring to temperature. In battery charging/discharging 1 C is the current you would get if you could discharge a fully charged battery in 1 hour at a constant current. If a battery's stated capacity is say 2000 mAh then 1 C for that battery is 2000 mA. Recommended discharge and charge (if applicable) rates are usually specified in terms of C. For example the usual recommendations for charging Panasonic Eneloop batteries is 0.5 - 1 C. So if you are charging an AA which has about 2000 mAh capacity that would be 1000 - 2000 mA, but if you were charging an AAA which has something like 900 mAh capacity that would be 450 - 900 mA.
- dtx1 3y ago
  Just for Context thats roughly an order of magnitude worse than current lithium ion and almost 2 orders of magnitude worse than lithium iron phosphate.
simondotau 3y ago
It seems there's news of a battery breakthrough every week. I've learned to temper expectations, because so many "breakthroughs" turn out to be dead ends. Because it's not enough for a battery to be incredibly light, or made of abundant materials, or last for ten thousand cycles. It needs to be good any many things and at least okay at most things. E.g.— • How much capacity per dollar? • How much capacity per kilogram? • How much capacity per litre? • How quickly can it be charged? • How quickly can it be discharged? • How much energy is lost between charging and discharging? • How predisposed is it to catching fire? • How available are the materials needed to manufacture it? • How available are the tools/skills required to manufacture it? • How resilient is it to mechanical stress, e.g. vibration? • How much does performance degrade per cycle? • How much does performance degrade when stored at a high state of charge? • How much does performance degrade when stored at a low state of charge? • How much does performance drop at high temperatures? • How much does performance drop at low temperatures? • How well can it be recycled at end-of-life? A sufficiently bad answer for any one of these could utterly exclude it from contention in many usages. A battery which scores well on everything except mechanical resilience is a non-starter for EVs, for example. On the other hand, a battery that's no good for EVs might be great for stationary storage. I'm only a layperson and this list is the result of just a few minutes thought. I'm sure someone with more familiarity with the subject could double this list. But the point is, when you daydream about some hypothetical future battery tech, you need to appreciate just how well today's lithium chemistries score in so many areas.
- HPsquared 3y ago
  There's probably a Nobel prize in it for anyone who can significantly improve on lithium ion. It's a tall order. Many have tried, many have failed. Eventually someone might succeed.
  - Turskarama 3y ago
    If someone managed to improve on it in every metric then yes, absolutely. The thing is though that you don't have to beat it on every metric to be useful, you have to be _good enough_ on every metric and then really good on one or two. For example, it's absolutely fine for a battery to weight five times as much if it doesn't need to be portable. Five times as heavy but half the cost per MWh? That's great for grid storage! Twice as expensive and non rechargeable but 4 times the capacity (per unit volume)? Great for pacemakers! It's all about finding the right niche.
sholladay 3y ago
Meanwhile, lithium-ion is improving remarkably each year. https://insideevs.com/news/581729/volumetric-energy-density-ev-batteries-growth/amp/ https://insideevs.com/news/581729/volumetric-energy-density-...
- doctor_eval 3y ago
  That graph is a bit deceptive; the X axis is not linear, but instead shows years 2008, 2010, 2013, 2017 and 2020.
  - DannyBee 3y ago
    It's wrong anyway. Even back in 2008, it was more than 50 watt hours per liter. The graph is taken straight from the DOE website, here: https://www.energy.gov/eere/vehicles/articles/fotw-1234-april-18-2022-volumetric-energy-density-lithium-ion-batteries#:~:text=In%202008%2C%20lithium%2Dion%20batteries,450%20watt%2Dhours%20per%20liter https://www.energy.gov/eere/vehicles/articles/fotw-1234-apri.... Without attribution of course. They just re cited the paper the DOE cites. The paper has no such graph: https://www.osti.gov/pages/servlets/purl/1842609 https://www.osti.gov/pages/servlets/purl/1842609 The graph is clearly wrong.
- _hypx 3y ago
  That graph is plainly wrong. The initial point is at the same level as a lead-acid battery. There is no chance it is legit.
  - DannyBee 3y ago
    They wouldn't know since they stole it from the DOE website here: https://www.energy.gov/eere/vehicles/articles/fotw-1234-april-18-2022-volumetric-energy-density-lithium-ion-batteries#:~:text=In%202008%2C%20lithium%2Dion%20batteries,450%20watt%2Dhours%20per%20liter https://www.energy.gov/eere/vehicles/articles/fotw-1234-apri.... (The cited paper does not contain this graph, see https://www.osti.gov/pages/servlets/purl/1842609 https://www.osti.gov/pages/servlets/purl/1842609)
Dead_Lemon 3y ago
I really enjoy watching Cayrex building interesting batteries on YouTube, like the Reusable Aluminum Air Battery, https://youtu.be/XxJ2FeUi6oI https://youtu.be/XxJ2FeUi6oI

59 points by rustoo 3y ago

I personally made similar devices in the lab over a decade ago (and yes, with Nafion and benzoquinones). They're very unstable. I'd file this under gimmick rather than novel tech.

skykooler 3y ago

> While the discharge capacity of SSAB-PDBM reduced to 44% after 30 cycles, by increasing the proton-conductive polymer content of the negative electrode, the researchers could significantly improve it to 78%. That's still a 22% drop in capacity after only 30 charge cycles; this system has a long way to go before becoming a practical battery.

fbdab103 3y ago
While probably not ideal for a phone or car, it could still have its uses. So long as it stabilizes at that 70%+ region, that is not potentially a deal-braker for grid installations. Which is an optimization of installation cost, maintenance, longevity, operating temperature/pressure requirements, charge/discharge rates, etc.
- DennisP 3y ago
  They didn't say it stabilizes, though. You'd think they'd mention that if it did.
- idontwantthis 3y ago
  If it stabilized then it would just be 30% heavier. I doubt it stabilizes.
trompetenaccoun 3y ago
Depends one the cost and environmental impact. I don't know anything about the compounds they used and anyway they're still experimental and could be replaced by others. But in stationary settings where size isn't an issue they can lose substantial capacity upfront and still be viable if they can be cheaply produced and don't involve complicated steps like in lithium mining for example.
- HPsquared 3y ago
  Flow batteries are better suited for stationary applications, I think. Liquids lend themselves to large-scale processing.
  - Turskarama 3y ago
    Flow batteries are pretty good but I think if the dirt cheap "heavy" chemistries such as liquid metal and iron-air take off then not needing any moving parts and having no risk of leaks is an advantage.
scandum 3y ago
> the coulombic efficiency of SSAB-PDBM was 84% at 4 C rate, which gradually decreased to 66% at 101 C rate. Lithium batteries are over 95% efficient, so a long way indeed. Since the battery contains water, I assume it doesn't work below 0 C.
- elcritch 3y ago
  It's a solid electrolyte battery, not water electrolyte based.
  - pengaru 3y ago
    There's clearly h2o leaving the oxygen positive electrode in the illustration at the top of TFA If the h2o ices up on that side, what happens to the battery? or is it not possible?
- tzs 3y ago
  I don't think 4 C and 101 C are referring to temperature. In battery charging/discharging 1 C is the current you would get if you could discharge a fully charged battery in 1 hour at a constant current. If a battery's stated capacity is say 2000 mAh then 1 C for that battery is 2000 mA. Recommended discharge and charge (if applicable) rates are usually specified in terms of C. For example the usual recommendations for charging Panasonic Eneloop batteries is 0.5 - 1 C. So if you are charging an AA which has about 2000 mAh capacity that would be 1000 - 2000 mA, but if you were charging an AAA which has something like 900 mAh capacity that would be 450 - 900 mA.
dtx1 3y ago
Just for Context thats roughly an order of magnitude worse than current lithium ion and almost 2 orders of magnitude worse than lithium iron phosphate.

simondotau 3y ago

It seems there's news of a battery breakthrough every week. I've learned to temper expectations, because so many "breakthroughs" turn out to be dead ends. Because it's not enough for a battery to be incredibly light, or made of abundant materials, or last for ten thousand cycles. It needs to be good any many things and at least okay at most things. E.g.— • How much capacity per dollar? • How much capacity per kilogram? • How much capacity per litre? • How quickly can it be charged? • How quickly can it be discharged? • How much energy is lost between charging and discharging? • How predisposed is it to catching fire? • How available are the materials needed to manufacture it? • How available are the tools/skills required to manufacture it? • How resilient is it to mechanical stress, e.g. vibration? • How much does performance degrade per cycle? • How much does performance degrade when stored at a high state of charge? • How much does performance degrade when stored at a low state of charge? • How much does performance drop at high temperatures? • How much does performance drop at low temperatures? • How well can it be recycled at end-of-life? A sufficiently bad answer for any one of these could utterly exclude it from contention in many usages. A battery which scores well on everything except mechanical resilience is a non-starter for EVs, for example. On the other hand, a battery that's no good for EVs might be great for stationary storage. I'm only a layperson and this list is the result of just a few minutes thought. I'm sure someone with more familiarity with the subject could double this list. But the point is, when you daydream about some hypothetical future battery tech, you need to appreciate just how well today's lithium chemistries score in so many areas.

HPsquared 3y ago
There's probably a Nobel prize in it for anyone who can significantly improve on lithium ion. It's a tall order. Many have tried, many have failed. Eventually someone might succeed.
- Turskarama 3y ago
  If someone managed to improve on it in every metric then yes, absolutely. The thing is though that you don't have to beat it on every metric to be useful, you have to be _good enough_ on every metric and then really good on one or two. For example, it's absolutely fine for a battery to weight five times as much if it doesn't need to be portable. Five times as heavy but half the cost per MWh? That's great for grid storage! Twice as expensive and non rechargeable but 4 times the capacity (per unit volume)? Great for pacemakers! It's all about finding the right niche.

sholladay 3y ago

Meanwhile, lithium-ion is improving remarkably each year. https://insideevs.com/news/581729/volumetric-energy-density-ev-batteries-growth/amp/ https://insideevs.com/news/581729/volumetric-energy-density-...

doctor_eval 3y ago
That graph is a bit deceptive; the X axis is not linear, but instead shows years 2008, 2010, 2013, 2017 and 2020.
- DannyBee 3y ago
  It's wrong anyway. Even back in 2008, it was more than 50 watt hours per liter. The graph is taken straight from the DOE website, here: https://www.energy.gov/eere/vehicles/articles/fotw-1234-april-18-2022-volumetric-energy-density-lithium-ion-batteries#:~:text=In%202008%2C%20lithium%2Dion%20batteries,450%20watt%2Dhours%20per%20liter https://www.energy.gov/eere/vehicles/articles/fotw-1234-apri.... Without attribution of course. They just re cited the paper the DOE cites. The paper has no such graph: https://www.osti.gov/pages/servlets/purl/1842609 https://www.osti.gov/pages/servlets/purl/1842609 The graph is clearly wrong.
_hypx 3y ago
That graph is plainly wrong. The initial point is at the same level as a lead-acid battery. There is no chance it is legit.
- DannyBee 3y ago
  They wouldn't know since they stole it from the DOE website here: https://www.energy.gov/eere/vehicles/articles/fotw-1234-april-18-2022-volumetric-energy-density-lithium-ion-batteries#:~:text=In%202008%2C%20lithium%2Dion%20batteries,450%20watt%2Dhours%20per%20liter https://www.energy.gov/eere/vehicles/articles/fotw-1234-apri.... (The cited paper does not contain this graph, see https://www.osti.gov/pages/servlets/purl/1842609 https://www.osti.gov/pages/servlets/purl/1842609)

Dead_Lemon 3y ago

I really enjoy watching Cayrex building interesting batteries on YouTube, like the Reusable Aluminum Air Battery, https://youtu.be/XxJ2FeUi6oI https://youtu.be/XxJ2FeUi6oI