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Power Transportation Hardware

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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  • 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".

  • by IBitOBear ( 410965 ) on Monday June 06, 2011 @07:36PM (#36357240) Homepage Journal

    There is a reason it's called "topping off" if my father's long-ago explanation is to be believed...

    First: there is no "drain hole" in the fuel system (at least in the US etc) since the fuel system is supposed to be vapor tight. There _is_ a small drain hole behind the typical fuel filler door which mostly exists to prevent water from getting caught inside the compartment and rusting things out. That said...

    We pump gas _far_ too fast to be environmentally sound. It _froths_ out of the hose in a turbulent flow and a lot of vapor escapes because of the frothing, which is why we now have those vapor recovery hoods etc on a lot of pumps.

    When the tank is nearly full, e.g. "as full as it ought to be", the froth boils up the fill-pipe and triggers the back-pressure sensor causing the nozzle to click closed. I few seconds latter the frothing settles and there is now a space in the tank. "Topping off" is the attempt to fill that space.

    Back in the before time, that is, before gas was expensive and mileage was important, getting that quarter of a gallon into the car meant getting another three or four miles before needing to fill up. Nobody cared that the net effect was 3 cents of gas gushing out of the pipe and onto the ground because everybody thought "what the heck" because nobody knew that dispersing hydrocarbons did anything but smell nice and industrial. Plus gas fill points were low and typically at the bumper so it didn't even ruin the paint job.

    Now days, "topping off" is as bad as it ever was, and worse too boot. The attempt to fill that last little bit not only causes gas to gush out onto your paint job, and pollute the environment, not it also can put liquid gasoline into the vapor recovery system. This can cause the back-pressure valve in the pump to "miss" the fact that froth is rising in the fill tube. You can end up pumping gas right back out of your car and into the gas station tanks ( this costs you money) and then when you separate the nozzle from the car a _lot_ of gas can have collected in that rubber hood thing which then goes everywhere.

    Better yet, then next guy will get the same treatment if there is still liquid gas in the vapor recovery system. I filled up my Prius in a bad part of town the other day, and when I pulled the nozzle out, a good 3 cups of gas went everywhere. Some person before me must have "topped off" and that turned the vapor recovery system into a siphon. Who knows how many people that effected before me, and after as now _my_ gas was in the hose for the next guy.

    Your gas tank is never supposed to be _full_ by absolute measure. Just like every other container of liquid you have ever dealt with, there is a little space at the top.

    Topping off _any_ container is the act of trying to fill that last little bit between "properly full" and "absolutely full" and it _always_ results in waste and spillage due to over-filling.

    In my grandfather's age, the tank wasn't full until some spilled out. Topping off was the norm. People still do it because that's how they learned to do it "no matter what the sign says, my daddy showed me good"; this is the law of the dumb.

  • 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.

"An open mind has but one disadvantage: it collects dirt." -- a saying at RPI