MIT: Battery Breakthrough/Update on Artificial Leaf

June 9, 2011

A new battery technology developed at MIT promises to halve the size of battery systems for electric vehicles, and dramatically improve the ease of recharging or “refueling” electric vehicles.

MIT News:

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.

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.

IEEE Spectrum raises one question:

The design also separates the storing and discharging of the battery into two different physical structures. According to Chiang, this separated architecture will enable batteries to be designed more efficiently.

Since the design is expected to reduce the size (and cost) of a battery system by as much as half, it is being touted as a way to make electric vehicles more competitive with internal combustion engines.

Chiang and his researchers have even gone so far as to dub the semi-solid liquid “Cambridge Crude”, no doubt a reference to their Cambridge, MA location. The researchers also posit the idea that the “Cambridge Crude” could be pumped like gas to recharge a car. However, I would make one small caveat on that notion: what are you supposed to do with the semi-solid liquid that you’re disposing of? I expect that one would run into all sorts of environmental concerns.

Artificial Leaf update:

An important step toward realizing the dream of an inexpensive and simple “artificial leaf,” a device to harness solar energy by splitting water molecules, has been accomplished by two separate teams of researchers at MIT. Both teams produced devices that combine a standard silicon solar cell with a catalyst developed three years ago by professor Daniel Nocera. When submerged in water and exposed to sunlight, the devices cause bubbles of oxygen to separate out of the water.

The next step to producing a full, usable artificial leaf, explains Nocera, the Henry Dreyfus Professor of Energy and professor of chemistry, will be to integrate the final ingredient: an additional catalyst to bubble out the water’s hydrogen atoms. In the current devices, hydrogen atoms are simply dissociated into the solution as loose protons and electrons. If a catalyst could produce fully formed hydrogen molecules (H2), the molecules could be used to generate electricity or to make fuel for vehicles. Realization of that step, Nocera says, will be the subject of a forthcoming paper.

Further testing is needed to upgrade the process from “science project” to “engineering design.  Nocera hopes the artificial leaf will become reality in 3 years.

4 Responses to “MIT: Battery Breakthrough/Update on Artificial Leaf”


  1. I picked up mention of the MIT developments elsewhere and am pretty sure the whole point is that the spent fluid is sent back for recycling. I’m not sure whether “sent back” is a factory somewhere or could be in the service station where the motorist just recharged their car.

    ….just backtracked to my previous link.

    From
    …..Being able to recharge the waste stream is one of the main advantages, he added. “It’s as if you had a way of capturing the carbon and water and turning it back into gasoline at the gas station.”


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