6 ms·

MIT students develop liquid fuel for electric cars

153 points by jamesjyu 15y ago

ovi256 15y ago
As I've learned when such promising technology is announced, I'll wait for system integration prototypes to roll out.
ender7 15y ago
Original article: http://web.mit.edu/newsoffice/2011/flow-batteries-0606.html http://web.mit.edu/newsoffice/2011/flow-batteries-0606.html
- invisible 15y ago
  "The company has already raised more than $16 million in venture capital and federal research financing." - Awesome! Much better details in this.
- tjmc 15y ago
  Original paper: http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/abstract;jsessionid=8AE6EDCECE055B97EB99CF4483EC426C.d01t02 http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/ab... (free access until 27 June 2011) This looks like a major breakthrough. Love the nickname - "Cambridge crude". As with all flow batteries, power density is low. But you could possibly compensate for that in vehicles with ultracapacitors which could also recapture energy from braking.
tansey 15y ago
Worth noting that the liquid is rechargeable/reusable: http://en.wikipedia.org/wiki/Flow_batteries http://en.wikipedia.org/wiki/Flow_batteries According to the Wikipedia page, the main issue with these batteries is low energy density. If this group has figured it out, they may be on to something huge.
- artmageddon 15y ago
  I agree, if a development like this were to happen for electric vehicles, adoption of them would skyrocket. The one thought I have is how much will this cost to produce initially per liter, as well as over time when it reaches a critical mass?
jws 15y ago
The highest energy density listed for the electrolytes on the wikipedia page for flow batteries is 75 watt hours/kg, that is about 0.25Mj/kg. Gasoline is 42Mj/kg. The original MIT release claims a 10 fold improvement in energy densities over existing flow batteries, but that is still more than an order of magnitude worse than the incumbent fuel.
- artmageddon 15y ago
  Pardon my ignorance, but are the flow batteries you mention the same type used in existing electric vehicles? It can't be assumed that the energy density of flow batteries will ever match as gasoline, but people might be willing to accept the difference if it means more infrastructure adoption and less time spent recharging vehicles.
  - jws 15y ago
    Good point. I've not seen flow batteries in existing vehicles. Electric vehicles use NiMH batteries (0.25 MJ/kg), lithium batteries (0.4 to 0.7 MJ/kg) or lead acid (0.14 MJ/kg fork trucks, but they need mass anyway). Guessing at the numbers MIT is avoiding naming in that press release, they might get to something three times better than the current lithium batteries, but you also have to add in the mass of the pumps, and the reaction part of the battery. It could "win", but it won't be a game changer. Putting aside vehicles though, flow batteries have some interesting properties for utility scale energy storage. The rate at which you can store or retrieve energy is independent from the amount of energy you can store. The first is by the size of your reactor, the second is by the volume of your storage tanks. It is possible if they are using common enough elements for their fluid that they could be a good answer for peak load shifting or production storing.
    - uvdiv 15y ago
      Here's the numbers: ...we estimate that optimized SSFC systems using established lithium intercalation compounds could have energy densities of 300–500 Wh L−1 (specific energy 130–250 Wh kg−1), which would satisfy metrics considered necessary for widespread adoption of all-electric vehicles.[4] Further improvements would be possible by ‘dropping in’ higher-energy-density or lower-cost storage compounds in the SSFC platform as they are developed. http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/full http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/fu... (linked from http://web.mit.edu/newsoffice/2011/flow-batteries-0606.html http://web.mit.edu/newsoffice/2011/flow-batteries-0606.html) So 0.47-0.90 MJ/kg. Based on theoretical calculations -- they haven't actually engineered this.
hugh3 15y ago
Often in these sorts of articles, you can tell what the big problems are by the fact that they're not even mentioned. The big unmentioned problems here seem to be: a) Cost b) Cost c) Safety, and d) Cost I'm not sure what materials they're making these things from, but would it be fair to guess that it's something exotic and hard to fabricate?
- bellaire 15y ago
  From the article: "The tech supposedly makes the batteries up to ten times more efficient than their traditional counterparts, and even more importantly, the new tech is cheaper to produce."
  - MichaelApproved 15y ago
    Cheaper is meaningless in this context. For example, if the traditional counterparts cost $1,000/mile then $100/mile is still cheaper but still far from being pratical. We have no idea what it's cheaper than and by how much it's cheaper by. Of course, my numbers are completely made. It's just meant as an example.
    - invisible 15y ago
      I'm pretty sure it is saying 10x better and cheaper than a standard lithium ion for the same battery size. If they are not saying that then the sentence makes no sense.
- r00fus 15y ago
  Cost is a very complex thing, are you considering externalities? In other words, we're paying a pretty damn high price for "gas" right now (including externalities like pollution, wars, and oil spills). Alternatives have not taken off due to chicken/egg problem of adoption<->economies of scale. Also gas is not safe. It's highly combustible and toxic to humans: http://medicmagic.net/living-near-a-gas-station-increase-cancer-risks.html http://medicmagic.net/living-near-a-gas-station-increase-can...
kmod 15y ago
"liquid fuel for electric cars" -- what if we used refined petroleum as a secondary energy source? we probably wouldn't even need a large electric motor any more.
cagenut 15y ago
Here's a much better article with diagrams and more details: http://www.greencarcongress.com/2011/05/ssfc-20110526.html http://www.greencarcongress.com/2011/05/ssfc-20110526.html This really will be a major step forward if it pans out. Even if it doesn't work so great for cars it could be amazing for grid storage.
stretchwithme 15y ago
When a major change is made to how something is done, there really needs to be a very significant improvement that makes the cost of changing worthwhile. I think eventually this will happen with electric vehicles, but no one knows for sure. Which is probably why we shouldn't subsidize solutions that are not compelling enough. The current electric vehicles aren't even as good as what they are attempting to replace and wouldn't be available at all without the massive subsidies. If we do subsidize things in an effort to "jumpstart" the change, we might actually switch to a system that is not compelling enough and might get persuaded to jumpstart the next generation, which might have been compelling enough on its own. And be stuck with the cost of the subsidies or paying the higher cost directly. Of course, such changes become so monolithic to begin with when government picks a standard and encourages everyone to adopt it. It may drive down costs in the short run, but it reduces progress in the long run. For example, the adoption of the NTSC tv format and enforcing it using the FCC. We got color. Then we got closed captioning. And that was probably all the innovation we got over 50 years. But look at how quickly video has evolved on personal computers by comparison.
briggsbio 15y ago
Is it a boolean though? "refuel or recharge"? Can flow-batteries be recharged AND also have the fluid exchanged? This would be very promising if it could match an electric car's battery AND be refueled. It may also lead to longer-lasting batteries overall. That would change the conversation. Charge the flow-battery in your garage at night, or if you're out and about or on a long trip, just "fill-er-up!" Better Place advocates having "battery swapping stations," but with the rapid change of innovation, battery requirements for different-sized cars, etc., that may be difficult to set up the infrastructure. Wired Article on Better Place: http://m.wired.com/autopia/2009/05/better-place/ http://m.wired.com/autopia/2009/05/better-place/

153 points by jamesjyu 15y ago

As I've learned when such promising technology is announced, I'll wait for system integration prototypes to roll out.

Original article: http://web.mit.edu/newsoffice/2011/flow-batteries-0606.html http://web.mit.edu/newsoffice/2011/flow-batteries-0606.html

invisible 15y ago
"The company has already raised more than $16 million in venture capital and federal research financing." - Awesome! Much better details in this.
tjmc 15y ago
Original paper: http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/abstract;jsessionid=8AE6EDCECE055B97EB99CF4483EC426C.d01t02 http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/ab... (free access until 27 June 2011) This looks like a major breakthrough. Love the nickname - "Cambridge crude". As with all flow batteries, power density is low. But you could possibly compensate for that in vehicles with ultracapacitors which could also recapture energy from braking.

tansey 15y ago

Worth noting that the liquid is rechargeable/reusable: http://en.wikipedia.org/wiki/Flow_batteries http://en.wikipedia.org/wiki/Flow_batteries According to the Wikipedia page, the main issue with these batteries is low energy density. If this group has figured it out, they may be on to something huge.

artmageddon 15y ago
I agree, if a development like this were to happen for electric vehicles, adoption of them would skyrocket. The one thought I have is how much will this cost to produce initially per liter, as well as over time when it reaches a critical mass?

jws 15y ago

The highest energy density listed for the electrolytes on the wikipedia page for flow batteries is 75 watt hours/kg, that is about 0.25Mj/kg. Gasoline is 42Mj/kg. The original MIT release claims a 10 fold improvement in energy densities over existing flow batteries, but that is still more than an order of magnitude worse than the incumbent fuel.

artmageddon 15y ago
Pardon my ignorance, but are the flow batteries you mention the same type used in existing electric vehicles? It can't be assumed that the energy density of flow batteries will ever match as gasoline, but people might be willing to accept the difference if it means more infrastructure adoption and less time spent recharging vehicles.
- jws 15y ago
  Good point. I've not seen flow batteries in existing vehicles. Electric vehicles use NiMH batteries (0.25 MJ/kg), lithium batteries (0.4 to 0.7 MJ/kg) or lead acid (0.14 MJ/kg fork trucks, but they need mass anyway). Guessing at the numbers MIT is avoiding naming in that press release, they might get to something three times better than the current lithium batteries, but you also have to add in the mass of the pumps, and the reaction part of the battery. It could "win", but it won't be a game changer. Putting aside vehicles though, flow batteries have some interesting properties for utility scale energy storage. The rate at which you can store or retrieve energy is independent from the amount of energy you can store. The first is by the size of your reactor, the second is by the volume of your storage tanks. It is possible if they are using common enough elements for their fluid that they could be a good answer for peak load shifting or production storing.
  - uvdiv 15y ago
    Here's the numbers: ...we estimate that optimized SSFC systems using established lithium intercalation compounds could have energy densities of 300–500 Wh L−1 (specific energy 130–250 Wh kg−1), which would satisfy metrics considered necessary for widespread adoption of all-electric vehicles.[4] Further improvements would be possible by ‘dropping in’ higher-energy-density or lower-cost storage compounds in the SSFC platform as they are developed. http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/full http://onlinelibrary.wiley.com/doi/10.1002/aenm.201100152/fu... (linked from http://web.mit.edu/newsoffice/2011/flow-batteries-0606.html http://web.mit.edu/newsoffice/2011/flow-batteries-0606.html) So 0.47-0.90 MJ/kg. Based on theoretical calculations -- they haven't actually engineered this.

hugh3 15y ago

Often in these sorts of articles, you can tell what the big problems are by the fact that they're not even mentioned. The big unmentioned problems here seem to be: a) Cost b) Cost c) Safety, and d) Cost I'm not sure what materials they're making these things from, but would it be fair to guess that it's something exotic and hard to fabricate?

bellaire 15y ago
From the article: "The tech supposedly makes the batteries up to ten times more efficient than their traditional counterparts, and even more importantly, the new tech is cheaper to produce."
- MichaelApproved 15y ago
  Cheaper is meaningless in this context. For example, if the traditional counterparts cost $1,000/mile then $100/mile is still cheaper but still far from being pratical. We have no idea what it's cheaper than and by how much it's cheaper by. Of course, my numbers are completely made. It's just meant as an example.
  - invisible 15y ago
    I'm pretty sure it is saying 10x better and cheaper than a standard lithium ion for the same battery size. If they are not saying that then the sentence makes no sense.
r00fus 15y ago
Cost is a very complex thing, are you considering externalities? In other words, we're paying a pretty damn high price for "gas" right now (including externalities like pollution, wars, and oil spills). Alternatives have not taken off due to chicken/egg problem of adoption<->economies of scale. Also gas is not safe. It's highly combustible and toxic to humans: http://medicmagic.net/living-near-a-gas-station-increase-cancer-risks.html http://medicmagic.net/living-near-a-gas-station-increase-can...

kmod 15y ago

"liquid fuel for electric cars" -- what if we used refined petroleum as a secondary energy source? we probably wouldn't even need a large electric motor any more.

cagenut 15y ago

Here's a much better article with diagrams and more details: http://www.greencarcongress.com/2011/05/ssfc-20110526.html http://www.greencarcongress.com/2011/05/ssfc-20110526.html This really will be a major step forward if it pans out. Even if it doesn't work so great for cars it could be amazing for grid storage.

stretchwithme 15y ago

When a major change is made to how something is done, there really needs to be a very significant improvement that makes the cost of changing worthwhile. I think eventually this will happen with electric vehicles, but no one knows for sure. Which is probably why we shouldn't subsidize solutions that are not compelling enough. The current electric vehicles aren't even as good as what they are attempting to replace and wouldn't be available at all without the massive subsidies. If we do subsidize things in an effort to "jumpstart" the change, we might actually switch to a system that is not compelling enough and might get persuaded to jumpstart the next generation, which might have been compelling enough on its own. And be stuck with the cost of the subsidies or paying the higher cost directly. Of course, such changes become so monolithic to begin with when government picks a standard and encourages everyone to adopt it. It may drive down costs in the short run, but it reduces progress in the long run. For example, the adoption of the NTSC tv format and enforcing it using the FCC. We got color. Then we got closed captioning. And that was probably all the innovation we got over 50 years. But look at how quickly video has evolved on personal computers by comparison.

briggsbio 15y ago

Is it a boolean though? "refuel or recharge"? Can flow-batteries be recharged AND also have the fluid exchanged? This would be very promising if it could match an electric car's battery AND be refueled. It may also lead to longer-lasting batteries overall. That would change the conversation. Charge the flow-battery in your garage at night, or if you're out and about or on a long trip, just "fill-er-up!" Better Place advocates having "battery swapping stations," but with the rapid change of innovation, battery requirements for different-sized cars, etc., that may be difficult to set up the infrastructure. Wired Article on Better Place: http://m.wired.com/autopia/2009/05/better-place/ http://m.wired.com/autopia/2009/05/better-place/