13 ms·

Supercapacitors are now carbon-free and more powerful

78 points by Parbeyjr 10y ago

kctess5 10y ago
Classic modern reporting - doesn't link to the source or even cite the paper. Here's the source: http://www.nature.com/nmat/journal/vaop/ncurrent/pdf/nmat4766.pdf http://www.nature.com/nmat/journal/vaop/ncurrent/pdf/nmat476... Web version: http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat4766.html http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat47...
- Pitarou 10y ago
  Not to mention: written by someone who doesn't haven't a clue about what they are writing about. I quote: > ... although conventional batteries have a slower recharging time, the fact that they maintain their charging capacity over a longer period because makes Li-ion the more efficient choice over carbon-based supercapacitors. Nope. That's not it.
  - akiselev 10y ago
    That description is so bad it makes me wonder whether the author even looked up capacitors on Wikipedia or if they just paraphrased what they think they remember from high school physics.
mchannon 10y ago
Carbon-free implies that there is zero carbon in this technology. In fact, the MOF material is based on organic (carbon-bearing) molecules. "non-carbon-based" would be more apt, since this is definitely a change from carbon-based electrodes.
- takingflac 10y ago
  I agree the current phrasing is at best easy to misunderstand at worst misleading. Another phrase like mchannon is suggesting or perhaps "No longer uses just carbon" would be more acceptable.
flexie 10y ago
That is good news. How long time would it take this research to result in improved batteries being marketed for electric vehicles?
- sgift 10y ago
  Maybe a year, maybe twenty. The tragic of research is that you have no idea before, so many great results never make it to market or far later than expected. But some day .. hopefully ..
- baldfat 10y ago
  this is one of a hundred such new battery technology we have been reading for the last 15 years. Batteries still have not changed in any great leap yet.
  - flexie 10y ago
    I don't know if that's true but save for electric vehicles, has there been any major interest in improving batteries much beyond what they do? Batteries have been mass marketed for laptops and cellphones in the past couple of decades and have improved steadily for the increasing needs in those markets. It's okay for cell phones to last for a day and to charge in an hour. But with electric cars, which are only really starting to pick up in the last 2-3 years or so, demand for longer range and faster charging is quite different.
    - baldfat 10y ago
      https://blogs.scientificamerican.com/the-curious-wavefunction/moores-law-and-battery-technology-no-dice/ https://blogs.scientificamerican.com/the-curious-wavefunctio...
franciscop 10y ago
If I'm not mistaken the biggest disadvantage of supercapacitors is the energy density by mass[1], which means that while they hold a good power density by mass it's only temporary. Good at sprinting not so good at marathons. It's great that there are advances in the field for many reasons, but I don't think they could replace batteries in the short-middle term, which seems to be the point of the "scientific click-bait" article. [1] http://berc.berkeley.edu/storage-wars-batteries-vs-supercapacitors/ http://berc.berkeley.edu/storage-wars-batteries-vs-supercapa...
- Retric 10y ago
  Regenerative breaking systems is one of the obvious places for supercapacitors. They are not quite at the energy density or cost level where every car uses them, but with some minor improvements they will become standard. The advantage is of course better mileage and increased battery lifespan. PS: There are even advantages with IC engines: http://articles.sae.org/11845/ http://articles.sae.org/11845/
  - franciscop 10y ago
    I didn't think about regenerative breaking and of course it looks like a good place. But in the end of the cannot this be absorbed by the batteries with a good configuration? I mean, adding N supercapacitors that can absorb X power each would be proportional as configuring it as M batteries (where M >> N) charging that can absorb Y power each where Y = X * N / M => Y << X, which seems doable. So you'd either need enough capacitors to use them effectively (adding cost/complexity) or enough batteries, right? Is that the reason why Tesla can do regenerative braking except for strong stops? Because the batteries can absorb part but not all of the sudden energy?
    - jon_richards 10y ago
      I imagine the strong stop problem is more about actually stopping the car fast enough. Easier to do with friction than induction.
cheiVia0 10y ago
Could this be used to charge your car's supercaps in 30s and have them feed into the batteries over a longer period of time?
- vincnetas 10y ago
  I think charging cables would melt from such currents. Or you would need a superconductor charging cables for your supercapacitors. Super everything :)
  - geon 10y ago
    Thicker cables? Or would they be too heavy?
    - emeraldd 10y ago
      There will be a physical limit when you attach the cables to the capacitor. At some point, the cable will be larger than the capacitor itself. Also, there are internal components (i.e. the leads attaching to the 'plates') that will become limiting factors. All that to say, there's a physical limit to how much bigger you can make the cables and actually still attach them to the capacitor.
      - geon 10y ago
        At some point, the thermal capacity of the cables will approach that of the brake discs of a normal car. They rarely get hot enough to melt, even though they pretty much absorb the entire braking power. I'd calculate the resistance of copper cables vs car mass and delta v, but I'm too lazy.
  - fzzzy 10y ago
    Could use higher voltages instead.
    - achr2 10y ago
      Not for supercaps, most have a breakdown voltage below 5 V.
audunw 10y ago
Charging speed is almost irrelevant for EVs. In the end you're limited by the amount of power you can push through a liquid cooled charging cable, and traditional batteries can almost certainly be engineered to handle that current. Once you get to that level, further improvements will not be that interesting. Maybe we'll never reach ICE refueling speed. But with electric you can put a charging spot on every parking space in supermarkets etc, and people can just leave the car charging while they shop. Energy density is the only thing that matters. Good super capacitors have other great usecases though. But maybe not as sexy.
- nbadg 10y ago
  This may be true at first glance, but if you try to incorporate more advanced EV features, and in particular, regenerative braking, you very quickly do need to care about maximum charge/discharge rates. Your brakes dissipate a great deal of energy very quickly; to resorb that back into usable potential is something that supercaps are exceptionally good at facilitating. That being said, in this case, you're likely best off using a supercap buffer between your batteries and the wheels, but that makes your power management and delivery systems substantially more complicated.
gene-h 10y ago
MOFs are one of the coolest nanomaterials. They are easy to customize and are sort of like molecular tinker toys. One can make a new MOF with the same structure by exchanging one of the molecular struts for another. In addition they self assemble and can be made by the ton. I don't think we can make carbon nanotubes by the ton. Chris Wilmer, a well known MOF researcher and bitcoin proponent, has an interesting talk on MOFs: https://www.youtube.com/watch?v=n1hcF2kYlC0 https://www.youtube.com/watch?v=n1hcF2kYlC0

78 points by Parbeyjr 10y ago

Classic modern reporting - doesn't link to the source or even cite the paper. Here's the source: http://www.nature.com/nmat/journal/vaop/ncurrent/pdf/nmat4766.pdf http://www.nature.com/nmat/journal/vaop/ncurrent/pdf/nmat476... Web version: http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat4766.html http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat47...

Pitarou 10y ago
Not to mention: written by someone who doesn't haven't a clue about what they are writing about. I quote: > ... although conventional batteries have a slower recharging time, the fact that they maintain their charging capacity over a longer period because makes Li-ion the more efficient choice over carbon-based supercapacitors. Nope. That's not it.
- akiselev 10y ago
  That description is so bad it makes me wonder whether the author even looked up capacitors on Wikipedia or if they just paraphrased what they think they remember from high school physics.

mchannon 10y ago

Carbon-free implies that there is zero carbon in this technology. In fact, the MOF material is based on organic (carbon-bearing) molecules. "non-carbon-based" would be more apt, since this is definitely a change from carbon-based electrodes.

takingflac 10y ago
I agree the current phrasing is at best easy to misunderstand at worst misleading. Another phrase like mchannon is suggesting or perhaps "No longer uses just carbon" would be more acceptable.

flexie 10y ago

That is good news. How long time would it take this research to result in improved batteries being marketed for electric vehicles?

sgift 10y ago
Maybe a year, maybe twenty. The tragic of research is that you have no idea before, so many great results never make it to market or far later than expected. But some day .. hopefully ..
baldfat 10y ago
this is one of a hundred such new battery technology we have been reading for the last 15 years. Batteries still have not changed in any great leap yet.
- flexie 10y ago
  I don't know if that's true but save for electric vehicles, has there been any major interest in improving batteries much beyond what they do? Batteries have been mass marketed for laptops and cellphones in the past couple of decades and have improved steadily for the increasing needs in those markets. It's okay for cell phones to last for a day and to charge in an hour. But with electric cars, which are only really starting to pick up in the last 2-3 years or so, demand for longer range and faster charging is quite different.
  - baldfat 10y ago
    https://blogs.scientificamerican.com/the-curious-wavefunction/moores-law-and-battery-technology-no-dice/ https://blogs.scientificamerican.com/the-curious-wavefunctio...

franciscop 10y ago

If I'm not mistaken the biggest disadvantage of supercapacitors is the energy density by mass[1], which means that while they hold a good power density by mass it's only temporary. Good at sprinting not so good at marathons. It's great that there are advances in the field for many reasons, but I don't think they could replace batteries in the short-middle term, which seems to be the point of the "scientific click-bait" article. [1] http://berc.berkeley.edu/storage-wars-batteries-vs-supercapacitors/ http://berc.berkeley.edu/storage-wars-batteries-vs-supercapa...

Retric 10y ago
Regenerative breaking systems is one of the obvious places for supercapacitors. They are not quite at the energy density or cost level where every car uses them, but with some minor improvements they will become standard. The advantage is of course better mileage and increased battery lifespan. PS: There are even advantages with IC engines: http://articles.sae.org/11845/ http://articles.sae.org/11845/
- franciscop 10y ago
  I didn't think about regenerative breaking and of course it looks like a good place. But in the end of the cannot this be absorbed by the batteries with a good configuration? I mean, adding N supercapacitors that can absorb X power each would be proportional as configuring it as M batteries (where M >> N) charging that can absorb Y power each where Y = X * N / M => Y << X, which seems doable. So you'd either need enough capacitors to use them effectively (adding cost/complexity) or enough batteries, right? Is that the reason why Tesla can do regenerative braking except for strong stops? Because the batteries can absorb part but not all of the sudden energy?
  - jon_richards 10y ago
    I imagine the strong stop problem is more about actually stopping the car fast enough. Easier to do with friction than induction.

cheiVia0 10y ago

Could this be used to charge your car's supercaps in 30s and have them feed into the batteries over a longer period of time?

vincnetas 10y ago
I think charging cables would melt from such currents. Or you would need a superconductor charging cables for your supercapacitors. Super everything :)
- geon 10y ago
  Thicker cables? Or would they be too heavy?
  - emeraldd 10y ago
    There will be a physical limit when you attach the cables to the capacitor. At some point, the cable will be larger than the capacitor itself. Also, there are internal components (i.e. the leads attaching to the 'plates') that will become limiting factors. All that to say, there's a physical limit to how much bigger you can make the cables and actually still attach them to the capacitor.
    - geon 10y ago
      At some point, the thermal capacity of the cables will approach that of the brake discs of a normal car. They rarely get hot enough to melt, even though they pretty much absorb the entire braking power. I'd calculate the resistance of copper cables vs car mass and delta v, but I'm too lazy.
- fzzzy 10y ago
  Could use higher voltages instead.
  - achr2 10y ago
    Not for supercaps, most have a breakdown voltage below 5 V.

audunw 10y ago

Charging speed is almost irrelevant for EVs. In the end you're limited by the amount of power you can push through a liquid cooled charging cable, and traditional batteries can almost certainly be engineered to handle that current. Once you get to that level, further improvements will not be that interesting. Maybe we'll never reach ICE refueling speed. But with electric you can put a charging spot on every parking space in supermarkets etc, and people can just leave the car charging while they shop. Energy density is the only thing that matters. Good super capacitors have other great usecases though. But maybe not as sexy.

nbadg 10y ago
This may be true at first glance, but if you try to incorporate more advanced EV features, and in particular, regenerative braking, you very quickly do need to care about maximum charge/discharge rates. Your brakes dissipate a great deal of energy very quickly; to resorb that back into usable potential is something that supercaps are exceptionally good at facilitating. That being said, in this case, you're likely best off using a supercap buffer between your batteries and the wheels, but that makes your power management and delivery systems substantially more complicated.

gene-h 10y ago

MOFs are one of the coolest nanomaterials. They are easy to customize and are sort of like molecular tinker toys. One can make a new MOF with the same structure by exchanging one of the molecular struts for another. In addition they self assemble and can be made by the ton. I don't think we can make carbon nanotubes by the ton. Chris Wilmer, a well known MOF researcher and bitcoin proponent, has an interesting talk on MOFs: https://www.youtube.com/watch?v=n1hcF2kYlC0 https://www.youtube.com/watch?v=n1hcF2kYlC0