MIT's liquid battery could 'refuel' in minutes

Amazing tech stories come out all the time, but since last week, one making the rounds with more than a little hope is a lab-based experimental battery invented by students at MIT based on a two-part liquid electrolyte called “Cambridge Crude.”

The battery is being developed for EVs and grid storage and could deliver more energy density than lithium-ion batteries while being more cost effective. Even more intriguing is it could overcome a common objection to present-tech batteries in that it can be “refueled” with the pump-able liquid as petrol cars do in minutes, thus promising to relegate long recharging times to distant memory.

Yet-Ming Chiang – one of the founders of A123 Systems – is the project’s supervising professor, and said the team’s mission was no less than “to reinvent the rechargeable battery,” and he expects to have a fully operational prototype suitable for electric cars in the next 18 months.

The new battery design, which you can read full details about in a technical paper, has been licensed to 24M Technologies which is working on perfecting the recipe, as it were. This Massachusetts-based organization branched out from A123 Systems – which itself branched from MIT – and is doing the research with $16 million in venture capital and U.S. Department of Defense funding.

According to MIT News, the battery employs an innovative architecture called a semi-solid flow cell. In it, charged particles float in a liquid carrier between two containers.

Until now, flow battery technology has been known, but energy density was too low. The Cambridge Crude is said to have 10 times more energy density than previous liquid flow battery electrolytes.

The unique difference of the MIT design is that it utilizes proven lithium-ion chemistry broken into tiny particles merged into the liquid matrix.

In brief, the way it works is the battery’s electrically active components – the positive and negative electrodes, or cathodes and anodes – are composed of particles suspended in the liquid electrolyte.

These two different suspensions are intended to be stored in separate tanks in a vehicle, then slowly pumped through systems separated by a filter, such as a thin porous membrane. When they come in contact, they exchange ions and create electricity.

The battery’s separation feature is in contrast to conventional batteries in which energy storage and discharge take place in the same structure. Chiang said batteries can be designed more efficiently by separating these functions.

To recharge, electricity is input to separate the particles that make up each electrode. A couple potential ways to quickly “refuel,” would be either pumping out the expended liquid slurry, and replacing with fresh, similar to gas or diesel (except the pumping out part). Or alternately, a complete tank swap system could be designed such as Better Place now proposes with solid batteries.

The initial promise of Cambridge Crude’s has MIT researchers hoping that they may have invented a completely new family of viable batteries.

Source: GM-Volt


  • Shines

    Sounds promising. If enough liquid can be stored to drive more than 250 miles on a “tank” then I say go for it. But, no mention of how expensive the replacable battery liquid is. If I buy a gallon to recharge my battery for another 250 miles of charge and it costs $50.00 (but no pollution)…

  • Avromie

    Very interesting, the liquid can also be pumped out into a fast-charging unit and then pumped back in.

    The only issue that I find in replacing the “slurry” is that each person/vendor will have different quality “slurry” in their car based on their maintenance, so swapping it out is a worst-case solution.

  • DownUnder

    Yeah, I post a link to that subject on Plug-in hybrid cars website some days ago:

    http://www.plugincars.com/can-portable-fast-charging-trucks-rescue-evs-range-anxiety-fears-107282.html#comments

    Very interesting.

  • DownUnder

    Yeah, I posted a link to that subject on Plug-in hybrid cars website some days ago:

    http://www.plugincars.com/can-portable-fast-charging-trucks-rescue-evs-range-anxiety-fears-107282.html#comments

    Very interesting.

  • Lost Prius to wife

    This shows a two tank system were the used slurry pushes out the unused portion. Let’s now use a four tank or six tank system. The used slurry is pumped into two recharging tanks and recharged while the recharged slurry that was in the recharging tanks is pumped into the feed tanks for the battery portion. Tie this into a hybrid system with a motor / generator the way that the Prius does and go as far as one would want. Slurry worn out? Replace it. Now it comes down to how this energy storage system compares to other storage systems as to “Bang for the Buck”.

  • Jerry

    And how will this work in cold weather?

    When the heck will the future arrive? I live in Canada and want off gasoline / petroleum fuel!

  • Steme

    How much power is needed to pump the slurry?
    Supppose that figures into the overall efficiency of the system.

  • shweta007

    This information is really interesting, this method of recycling is very useful for future. thanks for this wonderful post .

  • tapra1

    , but energy density was too low. The Cambridge Crude is said to have 10 times more energy density than previous liquid flow battery electrolytes. Best Windows Hosting

  • tapra1

    Tie this into a hybrid system with a motor / generator the way that the Prius does and go as far as one would want. Slurry worn out? Replace it.

  • Anonymous

    why didn’t they compare liquid batteries against commercial lithium ion batteries in terms of energy density and volumetric densities? If they claim that they can use their batteries in EV, they should compare it with lithium ion batteries, not flow batteries.

  • Anonymous

    I found that the total weight of cathode and anode materials are almost 70% weight percent in lithium ion batteries. The MIT groups used almsot 50% cathode and anode in their batteries. This simply indicates that the liquid flow battery does not have higher energy density than commercial lithium ions cells. so i am not sure whether people really want to use it in their car!!