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MIT Develops Fast Charging Liquid Flow Batteries 135

An anonymous reader sends this from the MIT News office: "A radically new approach to the design of batteries, developed by researchers at MIT, could provide a lightweight and inexpensive alternative to existing batteries for electric vehicles and the power grid. The technology could even make 'refueling' such batteries as quick and easy as pumping gas into a conventional car (abstract). The new battery relies on an innovative architecture called a semi-solid flow cell, in which solid particles are suspended in a carrier liquid and pumped through the system. In this design, the battery’s active components — the positive and negative electrodes, or cathodes and anodes — are composed of particles suspended in a liquid electrolyte. These two different suspensions are pumped through systems separated by a filter, such as a thin porous membrane."
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MIT Develops Fast Charging Liquid Flow Batteries

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  • "That's pure capacitance gel..."
    • You beat me to it.

      The idea has been around a long time, but making it work is a wholly different kettle of electromotive potential.

      • Isn't this a kind of a fuel cell?
        • by IBitOBear ( 410965 ) on Tuesday June 07, 2011 @01:05AM (#36359526) Homepage Journal

          A fuel cell basically "burns" (uses up) its reagent to make electricity directly.

          This (according to the article) is a reversible reaction between two liquids, one acting as an anode and one acting as a cathode, where the reaction is bounded by a membrane. It is really more of the "capacitance gel" idea, only with two carries (which makes sense).

          Think of it as two halves of a standard battery that can only interact when brought into proximity. While electrons (or maybe ions or something beyond my simple ability translate, not having seen the research or studied in the field) pass through the membrane by definition, the idea is that the charged medium is not part of the fixed assembly, so the fixed assembly (the reactor and membrane) is permanent while the charged part moves.

          In a standard battery the anode and cathode are permanent parts of the battery. When the battery is discharged the whole battery is trashed. For instance, and alkaline battery is assembled in a charged state, the dissolving of the metals in the alkaline solution is what makes the voltage. Lead-acid batteries wear out because the lead is changed by the charging process (applying voltage in the presence of acid solution) and changed back by the discharge. This cycling slowly causes the lead to flake and degrade until there is either so much lead flakes in the battery that a cell shorts out because of the lead connecting the two parts, or the odd chemical impurities and available oxygen slowly make the lead into a chemical that will not react with the acid correctly any more.

          In this arrangement the parts that would degrade are in the fluids, draining and replacing the fluids "assembles a new, fully charged battery". In this model the ideal of pulling into a service station and replacing your discharged battery pack with a new, charged one, becomes practical.

          In the alternate, as a rechargeable battery the non-solid nature of the battery itself lets the battery be charged and cooled all at once. The anode and cathode material won't "flake" because it isn't sold to begin with. Plus nearly all of the anode and cathode material is used by weight, there is no "inner core" area acting as a superstructure. This should improve the energy density (how many kilowatt hours you can store per pound etc).

          In the rechargeable battery usage the battery would probably need to be changed regularly, like an oil change, but _then_ one could probably use charged plates to separate/filter the degraded particles from the good ones, so the "battery" could be recycled in place instead of having to take it back to a factory.

          There is a lot potential wins here, but it is _very_ unlike a fuel cell.

          • This is why oneshould avoid buying batteries with a dramatically higher CCA (cold cranking amperage) than the factory spec. To get that larger potential in the same size case, the number of lead plates is higher while also being much thinnner. The thinner plates break down faster and the individual cells in the battery short out more quickly.
          • "A fuel cell basically "burns" (uses up) its reagent to make electricity directly."

            Going to have to disagree with you here, a fuel cell is an electrochemical energy conversion device, which use a chemical reaction (in most cases a redox) to convert chemical bond energy to electrical energy. Generally this is run in one direction only, for instance hydrogen plus oxygen goes to water vapor and electricity. However, fuel cells by nature (not necessarily engineered for) are completely reversible. You can app

        • by sjames ( 1099 )

          Not quite. The fuel cell consumes fuel and an oxidizer in an electrochemical reaction. This is more a rechargable battery where anode and cathode are thick liquids. Unlike a fuel cell, if you exchange the liquids out, the spent ones can then be recharged in another battery. You can also just recharge it if you have the time.

  • Comment removed based on user account deletion
    • by vlm ( 69642 )

      I sure hope they can develop this concept into a design that can be used by consumers.

      Get prepared for plenty of toxic waste spills. I did some research on vanadium flow batteries a decade or so ago, and they're just too toxic for the average redneck or the average MBA to be placed in charge of. Like giving matches to a little kid.

      The bad news is the vanadium-based chemistries are probably the safest, least reactive, least corrosive of the flow batteries. The others are worse. Lithium chemistries that occasionally burst into flame, iron based chemistries that are basically controlled rus

      • Petrol (gasoline for the Americans), diesel and engine oil are all highly dangerous and extremely harmful to the environment if spilled. We still manage to use them in unimaginable quantities every day without unmanageable problems. I think the toxicity of liquid-based batteries would easily be mitigated by safe storage designs and fool-proof extraction and refilling procedures. Yeah, yeah, I know nothing is fool proof but you can imagine a pair of tubes you have to screw onto your car and an automated retr
  • I hate the word "could." It's so inconclusive. I always think of the Geico commercial. "15 minutes could save you 15 percent or more on your car insurance." Yeah, and if I buy a lottery ticket, I could win millions of dollars. I probably won't, but I could.

    I'm probably just being too cynical. This is an interesting development, and I should be more supportive. But I can't get excited when there's so much "could" in an article. Just not in my nature.

    • At least Geico's honest. Everyone else says that people who switch to them "save hundreds."

      Well fucking DUH. Why the hell ELSE would you switch?!

      (One cynic to another)

      • by agrif ( 960591 )

        Though completely off-topic, another reason people often save money when switching car insurance is that their cars are re-valued in the process. Of course, the car's current value is less than it was when the first insurance was purchased.

  • by IBitOBear ( 410965 ) on Monday June 06, 2011 @06:28PM (#36356630) Homepage Journal

    Don't spill that shit. Imagine the average "I always top off my tank" bone head at a "gas pump" spilling what is basically the first practical, room temprature binary explosive all over the outside of his Jetta. Granted it isn't a proper explosive, it would be more of a flash of heat and electrical potential as the two materials mixed without the interleaving membrane.

    As a sealed cell this is a fine idea. As a dispensed material it has "technical issues".

    • Could mean the end of self-serve pumps.

      • by danlip ( 737336 )

        Not sure full service helps. The only time I've seen someone spill gas all over the ground is the guy at a full service pump. I've never done it myself.

        • After borrowing my father's 4WD (not some big city pretender, but a proper off roader, diesel, 2 tanks, etc.) I went to fill it up as thanks. So, I filled up the 1st tank with 75 litres. Then I started fillling up the 2nd tank, and at about 20 litres, this passer by points out some liquid on the ground. I looked around and found that I'd stuck the bowser into a hole in the wall of the car for connecting water. Literally just a hole in the side of the car. So I had filled the car floor with 20 litres of

      • by LoRdTAW ( 99712 )

        Or it just means that the pump nozzle will have to plug into the fill port creating a liquid tight seal. There would also be a better over flow sensor to shut off the pump when the tank is full.

        Though, that means there will have to be a standardized fill port plug and it would have to accommodate both cars and heavy trucks.

        • That would be _FOUR_ liquids passing through the nozzle, not just one. Anode Charged and Cathode Charged going in, Anode Discharged and Cathode Discharged coming out. Mixing of the two charged liquids is the part I think would be hugely dangerous. Small amounts would invariably leak out in traces, and it only takes a some kid going "what's that daddy" for someone to touch the residue of both ports and shock or burn themselves.

          Closed systems would be much safer.

          • You know what else is not safe. Gasoline in a atmosphere containing oxygen.

            Honestly you would never get people to switch to gasoline today because of "safety concerns".
    • I love this moderation... it shoudl be +1 Flaimbait as any arrangement where four fluids (two charged fluids going in, and two discharged fluids coming out) of varying electrical potentials are being exchanged by someone of the same technical competence as, say, my mother, is _bound_ to end in flames, or at least tears... So having my mom pump this stuff, were she still alive, would be baiting flames indeed.

    • by IICV ( 652597 )

      Imagine the average "I always top off my tank" bone head at a "gas pump" spilling what is basically the first practical, room temprature binary explosive all over the outside of his Jetta.

      Do you really think that will be possible? The nozzle is already going to have to be different (since it's a binary compound) so they're going to have to redesign refueling anyway; if this goes commercial, they would build in safeguards against that, along with safeguards against accidentally putting some in your gas tank

    • Oh come on. Do you think LPG is tanked the same way petrol is? There already are working, foolproof, airtight connectors. You just need another one, that has four tubes - 2 in, 2 out. Add some sensors and you're off.

    • by sjames ( 1099 )

      They'll have to make damned sure you can't accidentally add cathode to the anode tank or vice versa or it'll be like the Dell laptop scaled up to OMG RUN size.

  • I was told about this sort of battery research 2nd hand about 8 years ago. Go to the 'petrol' station, attach a nozzle to the car, have the battery fluids replaced in a matter of a minute or two and off you go.
  • It's hardly a "radically new approach". The idea has been around for a long time and is easy to come up with off the the top of your head. I did in
    this slashdot post []. I'm not going to try to claim to have come up with a radically new approach there either since the idea has, in all likelihood, been around for about as long as batteries have (which is millenia, incidentally). Making it work is another matter altogether. If they have, it may be of some interest. Of course, in the post I linked to above, I spe

  • Instead of refueling a battery, you change the whole battery every time you stop at a "gas" station. The system has been used for gas cans for decades now and it works.

    I always wondered why do they assume that a car battery needs to be the same every time.

    • I'm not sure comparing 30lbm propane gas cylinder swaps to swapping batteries is a fair comparison. (Assuming that's what you meant; I'm not aware of anywhere that swaps gasoline cans.)

      That said, there are many groups working on swappable battery packs. Part of the problem, though, is that you have structural issues, alignment issues, storage issues (it's a lot easier to store and move liquids than it is 100+ lbm battery packs), matching the correct battery pack to the correct vehicle, and issues like makin

      • That is the basic idea, but it's really simple:

        I've seen working prototypes with working swappable batteries, so that shouldn't be an issue.

        Same way every car either takes leaded gasoline, unleaded gasoline or diesel, just make 3 types of batteries (different power for different requirements).

        The management part should be possible to overcome, especially because the adoption would be slow. The infrastructure would have to be built, but that doesn't meant it isn't doable. The up side is that you wouldn't req

        • by cnettel ( 836611 )
          What is also against is the current state of battery technology, i.e. we don't expect a stable fleet-wide solution to be based on current technology. Investing in standard form factors, designing drivetrains for their respective power delivery characteristics will just seem stupid.

          It's a bit like where we would be if we had at this moment just discovered petroleum as a viable engine fuel, but for some reason what we actually have in production is tar. Tar has terrible viscosity and it doesn't make a very g

    • Instead of refueling a battery, you change the whole battery every time you stop at a "gas" station. The system has been used for gas cans for decades now and it works.

      Trick is, a natural gas tank is just a can full of natural gas. and 30 pounds of natural gas is pretty much like any 30 pounds of natural gas.

      Batteries, on the other hand, age. As they get older, they hold less energy. So, you take your brand new battery (which you paid a pretty penny for when you bought your new electric car, and which w

      • by adolf ( 21054 )

        I think of it like a propane tank for a gas-fired barbeque grill:

        It's (usually) cheaper to refill the same tank over and over, but that takes more time, and can only be done at a limited selection of locations. Plus you've got to keep the thing free of rust, have it inspected periodically, and sometimes apply a new coat of paint. Eventually, the tank will fail inspection anyway, and needs replaced.

        And while some folks do all that, others just toss their empty tank into the car, and exchange it for a full

  • another amazing, wonderful, world changing, society fixing, all or our problems are solved, idea i heard about this week that ill be wondering what the hell ever happened to.... ten years from now when gas is $50/gallon to power a car that still doesnt fly and my cell phone charge still wont last more then an hour and all my friends are still obese and dying from cancer, lack of health care, with an upside down mortgage and no jobs and a microwave dinner that still fucking frozen in the middle.

    someday you s

    • You think your cell phone was made from magic, unicorn farts and wishes? Research into materials, software, hardware and EM radiation. While I understand your sentiment to some degree I think perhaps you should go and find, for yourself, examples of how research translates into technologies you can use. I'm sure MIT's website will quickly get you into a publicity section that'll be happy to educate you about their knowledge transfer activities.
      • by xmousex ( 661995 )

        yeah i came off critical of mit or something, i was really bugging more about tech journalism and OMG THE FUTURE!!! eeehhh .

  • by Anonymous Coward

    It's got electrolytes!

  • by cryfreedomlove ( 929828 ) on Monday June 06, 2011 @07:20PM (#36357112)
    I'm a big believer in the personal freedom offered by owner-driven vehicles, even if the driver is often the only person in the vehicle. Therefore, I am in favor of advanced battery technology that will allow a gradual transition of the world's fleet of personal vehicles to all electric drive rather than gasoline and diesel. Gasoline and diesel require a state of constant war in the Middle East to sustain.
    • And where will the electricity come from? Oil is energy; transportable and relatively dense, but it still accounts for more than 35% of US energy use. A "transition... to all electric" does not mean energy independence anymore than a "hydrogen economy" does.
      • Not oil, that's for sure. Right now, most electricity comes from gas and coal, nuclear and hydro. Oil makes up less than %1 of electricity generation. Even on a coal grid, there are less CO2 emissions from electric cars than gas cars. By the time all cars are electric, all electricity will come from solar and wind and hydro.
        • by fnj ( 64210 )

          2009 figures for U.S.: more than 2/3 from fossil fuels:
          coal 44.9%
          natural gas 23.4%
          nuclear 20.3%
          hydroelectric 6.9%
          other renewables 3.6%
          petroleum 1.0%

      • And where will the electricity come from? Oil is energy; transportable and relatively dense, but it still accounts for more than 35% of US energy use. A "transition... to all electric" does not mean energy independence anymore than a "hydrogen economy" does.

        I expect electricity generation to get cleaner, greener, and cheaper over the next 100 years as we finally figure out safe nuclear that can run without lies and coverups.

    • Gasoline and diesel require a state of constant war in the Middle East to sustain.

      Not for the US. The vast majority of our oil comes from Canada, Mexico, Venezuala, and other locations in the Americas.

  • by Jane Q. Public ( 1010737 ) on Monday June 06, 2011 @07:21PM (#36357124)
    I have a very big issue with what appears to be publicly-funded research being siphoned straight off into some corporate treasuries.

    This BS needs to stop. Repeal the Bayh-Dole Act []. It has done nothing but harm the public and our economy.
    • I once called MIT to inquire about getting license to a patent developed under a DOE grant. I was immediately transferred to their public affairs office where someone newly hired was rattling off the benefits of this act. I asked specifically about the process of bidding on the patents and was informed that for all intents and purposes it is by invitation only. The company getting all of the patents from the publicly funded research was owned by the head research scientist. Go figure.
      • You can either have academic labs researching things which are commercially interesting, and then give the professors working on it the perk of having the opportunity to commercialize it first (or at least royalties), or you can have academic labs researching things which the professor is academically interested in, and hope that it is commercially interesting. It is difficult to get both.

        Either you get people complaining that publicly funded research isn't free to the public to use, or you get people compl

        • I don't care what the dude does, I don't want my money funding private enterprise outside of my own direct investments. As for there getting 'first dibs', where did they get the resources and right for 'first dibs'? What right do they have to take my money by force and then create a company that is in direct competition with me? This is just in your mind?
          • Like how private trucks drive on public roads, and the government hires contractors to build infrastructure with tax money? You're a moron.

            • Um, I can use the roads and the infrastructure. They are 'public'. I can't use the publicly funded research that is exclusively licensed to private entities. Who's the moron?
          • "As for there getting 'first dibs', where did they get the resources and right for 'first dibs'?"

            It's called the Bayh-Dole Act, and it's an abomination. It was well-intended, I think, but it had unintended consequences.

            • Of the very few things I agree with FDR on, "In politics, nothing happens by accident. If it happens, you can bet it was planned that way" is certainly one of them. When I stated right, I think what I really meant was just laws. What just laws allow them to do this. The Constitution certainly does not grant Congress the power to fund private research. The Bayh-Dole Act is an example of the rule of man.
    • Personally, I have a lot more issues with it when the companies are fronts for Chinese gov. And yes, many of these VC companies that front the money are simply meant to hide what is going on.
  • Various governments around the world can impose a tax on the liquid, effectively being able to keep that huge income stream intact. When the price at the pump is 75% tax (in my glorious socialist EU country), at 1,70€/liter...

    Electric cars can use 20Amp 3-phase chargers to charge the batteries (albeit slowly) without requiring any changes in the electrical systems of a house. This makes government budget centers iffy, since they cannot easily tax you (despite the fact that in many EU countries you alre

    • At-home charging doesn't help when you're driving a distance larger than a single fill-up range. Nor does any charging scheme where the wait time is significant.

      There is a legitimate market for fuel substitutes that are easily flowed in & out of a vehicle.

  • As soon as some corporate battery behemoth hears this, they'll buy up the patent and lock it away so it can't be manufactured until the current battery designs stop making so much money.
  • that these positively and negatively-charged gels would make fine additions to Portal 2?
  • by wonkavader ( 605434 ) on Monday June 06, 2011 @08:34PM (#36357842)

    "The new semi-solid flow batteries pioneered by Chiang and colleagues overcome this limitation, providing a 10-fold improvement in energy density over present liquid flow-batteries, and lower-cost manufacturing than conventional lithium-ion batteries."

    It's statements like this that make me cringe when I look at the puffery which comes out of academia. 10 * better than A, and cheaper than B. Is it 10 * better than B? Or as good as B? Or (more likely) 1/10th as good as B.

  • Charge time isn't the problem. We have capacitors that can take millions of volts in milliseconds after all. The problem is Getting enough power to the refilling station to top off 20 cars at once. We're talking kilowatts here. And the cable going from the station to the vehicle would be the size of a tree trunk unless we get super conductors involved.
    • by glorybe ( 946151 )
      There are several problems but charge time is still one of them. We have crowded gas stations with lines at times already. Suppose that we had a twelve minute charge time as opposed to the three minute fill time for gasoline. It would be enough to clog cities with cars that could not move from lack of charge. Then there are the numerous power generating stations that would be needed to supply electricity to the charging stations. It gets worse. Even if each car must gather solar energy on its
      • by Anonymous Coward

        I think many people would choose to charge at home while their car is in the garage. Filling stations would be most often used for longer trips which is the vast minority of vehicles on the road.

        Also, yes electric motors generate heat. If that electricity came from solar, you know where most of the energy would have gone were it not for the solar collection? Heat. A tiny bit of reflection might escape the planet, but it would mostly go to heat.

    • Congestion actually helps solve the core issue. As congestion increases drivers begin to find other ways to get around. One electric bus could take up to 40 times the passengers of a single occupant vehicle, and transit becomes the best alternative for many commuters. In the long run cities become smaller and more accessible simply to overcome the inconvenience.
  • by Jack Malmostoso ( 899729 ) on Tuesday June 07, 2011 @04:04AM (#36360168)

    I just read the Advanced Energy Materials article (which you can easily find by googling the title and filtering for pdf).
    The idea itself is interesting, and could potentially remove some manufacturing problems (i.e. no need to dry, calender, cut electrodes and then assemble single cells and wire them in a pack) but I see a couple of big flaws in it:
    1) Let's get off the table the idea of "refueling". Li-ion batteries are assembled in their discharged state. The slurries containing LiCoO2 and Li4Ti5O12 (as per the article), when put in contact, produce exactly 0 energy. You have to either charge them using electricity, or prepare slurries of Li0.5CoO2 and Li7Ti5O12. Neither of the two materials is stable in air, thus I don't think it's possible to prepare a "refueling" system with current Li-ion battery materials.
    2) The beauty of Li-ion batteries is that they have 99.995% efficiency round-trip. This system seems to be based on very thick slurries which probably require strong pumps to circulate in a system, thus killing such efficiency.
    3) What's more, the slurries are prepared with highly flammable solvents (dioxolane). Not sure I'd like to carry around two tanks of the stuff, considering that a breach in the separator or in the "fuel" lines could ignite the whole thing.
    It is true that changing materials is a simpler problem than designing a completely new system, but as the authors themselves admit this is just a readaptation of an old system.
    I think it would be much more practical to redesign redox flow batteries to use non-aqueous electrolytes, thus allowing to work in a larger potential window (water only allows about 1.5V).
    I'm not sure things are looking up for A123, and I hope Prof. Chiang won't sink with this idea either. Good luck to all the researchers involved.

  • the batteries leaked again!
  • The only difference in this one is that the reacting material is a suspended, particular solid. There are commercial systems that use flow through batteries already.


    Flow batteries have historically had low energy densities, as the entire reacting mass was in solution. E.g. the article above cites 25-75 Wh/kg

    Which means a 50 kWh system would require roughly a cubic meter of tank, or about 5 standard drums. This is acceptable for a house, unworkable for a car. (50 kWh is about 2 days average power f

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