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MIT Develops Fast Charging Liquid Flow Batteries
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."
"That's pure capacitance gel..."
But clearly you have something better to say...
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.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
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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.
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".
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
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.
Nope. The anode and cathode in a car battery are lead/lead oxide/lead sulfate plates. There's an aqueous electrolyte, like in any wet cell battery.
Well, we are talking scales and scales here. The energy density of gasoline is still about a 100 times higher than that of the best batteries available. And it's not like there hasn't been any research on batteries.
Nitpic: the market for electric model airplanes took off before, with the NiMH cells. Of course, LiPo batteries are a lot nicer still.
Really? All of the challenges that a technology like this faces and you think the engineering involved in designing a connector that pumps in new fluid, pumps out old fluid, and doesn't allow bubbles into the system while being as easy to use as a gas pump nozzle is the kicker? Any mechanical engineering graduate who couldn't design that connector should be stripped of their degree. Making it reliable over thousands of uses and cheap?Tthat may take a little more work, but I would hardly rank the idea as the most outlandish concept in the article.
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 speculated that such an approach was almost guaranteed to end up as an environmental disaster in one way or another. My view on that may have softened a little since that post, but it would take some extraordinary proof for me to believe that it wouldn't end up resulting in thousands of plumes of heavy metal laden electrolyte under filling stations everywhere.
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.
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 should print an article when one of these brilliant mit/scientists/researchers/whoever people does something that actually makes it to market and changes the world.
It's got electrolytes!
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.
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.
- NiMH planes were hardly a joke. There was a lot of airracing done with them. Worked well.
- Many model planes get a lot of time out of their LiPo batteries, making the pilot want to have a break before the battery is empty. Gas, of course, runs much longer and you can sustain power for longer, but often the drawbacks (the mess) dominate.
Still, flying most distances of interest with a useful load is off limits for batteries.
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.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
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 already pay for a yearly tax in excess of 150€).
Cars with liquid-rechargeable batteries would allow them to control distribution of the liquid and keep taxing it.
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.
I would expect a standardized interlocking cartridge thing, or in-place charging.
In the case of replacing the fluids:
(1) The quantity of the two liquids would need to be kept in balance, which would be very hard to do using a "pumping" paradigm.
(2) The liquid isn't "consumed" (e.g. burnt) so much as "exhausted" (reduced to a non-charged state) so the spent liquid would need to be returned at the same time as the new liquid is supplied, which would get you up to four connections in the system instead of two.
(3) Punctures to containment would be hugely problematic, unlike gas, so the storage mechanism would need to have internal isolations to keep "the whole charge" from going off at once. (gas is amazingly stable in an accident since the liquid itself does not burn, not so much for the charged binary liquid in question.)
The in-place charging is much more likely. The charge process could be _very_ fast if the fluids are pumped quickly through a charging manifold. This would be the orthogonal structure to (or indeed the same exact structure as) the discharging manifold. Since the fluid is in motion it can be charged and _cooled_ immediately. That is the fluid would be pumped pass the charge point and into a heat sink or heat exchanger. In a full charging loop it might be chilled to an optimal pre-charge temperature, charged, and then cooled in series. Each individual annode/cathode element in the suspension would not have to take a full charge in one pass as you could keep circulating the fluid until the feedback voltage, charging current, and temperature told you the fluid was a charged as it was going to get. (and indeed the "worn-out-ness" of the fluid could probably be measured in the same way, telling you when you need to have your fluid changed by a proper professional etc.)
The system could work in a gas-pump like time and user modality (e.g. I put this thing in my car, watch it go "ding" for a while, then take it out and drive away) but the chance that the four fluids being exchanged by an average-joe in an air-gap setting is quite low.
No fluid exchange coupling known to date is absolutely residue free. It would only take one kid "checking out" the interlock and getting both liquids on his fingers and then touching them together to call in the liability lawyers big-time.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
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.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
that these positively and negatively-charged gels would make fine additions to Portal 2?
"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.
With a useful load is the real trick to electric anything.
Sure you can have an electric car today. Try loading up 2-3 of your friends, luggage for 4-5 days, to go anywhere?
The few cars that might get 200 mile range are suddenly cut down to 75.
Electric will come when two things happen. Better energy storage, and people get over nuclear power fears. With out nuclear power generation electric cars are worthless. Solar, wind hydro, geothermal, tidal, won't produce enough power to cover current needs, let alone tripling it by 30% of the population using electric cars.
i thought once I was found, but it was only a dream.
If you know your tank isn't anywhere near full, then you are not "topping off" technically or morally, you are continuing to fill your tank.
There are two primary reasons that the nozzle will trip "for no reason". (1) improperly inserted nozzles will self trip when their stream of gas hits the side of the pipe and causes back-pressure, and likewise for letting the nozzle back out of the pipe. (2) Someone before you topped off and got "just a little" liquid gas into the vapor recovery system, when those liquid drops hit the internal sensors the last-ditch anti-siphon system kicks in and trips the shutoff. Both conditions are the result of improper fueling technique by the current or previous operator. (A caveat here is that the equipment can, through continued mis-used get worn out but that's a compounded case of items 1 and 2.)
I had a car for a while that would only fill properly if I put the nozzle in at a slight angle because of item 1 and crappy design of the fill pipe.
If you put eight gallons of gas in a rated-ten-gallon tank that wasn't bone dry you have no reason to squeeze the handle again. And if you do and it trips _again_ and you squeeze the handle a third time you are wanking off.
I've watched people re-squeeze the handle like eight times. This is topping off at its most primal level of idiocy.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
Two fluids, out and in, reduce the mixing so that the fresh fluid is not diluted unacceptably by the stale, ensure none of the anode fluid _ever_ mixes with the cathode fluid, ensure that no person (including a curious child) is exposed to both fluids at once even if they "poke at" the nozzle. This is not a "fill the tank with gas" analog operation at all.
I think the material has great promise, and since it is fluid based, it is probably very able to be cooled quickly as it charges so a closed-loop fast charge in-place is probably _way_ more workable than replacing the fluid every time a charge is needed.
The gas-pump experience I would expect would be a "hose" from the pumping station which carried an electrical cable and a cooling loop. The fluids inside the closed system in the car would be pumped "briskly" though the charging manifold, the "nozzle" would sandwich the charging manifold and both apply the electric potential and aggressive chilling. The charged fluid would return to primary containment somewhat cool to the touch.
The cooling would alleviate the thermal degradation that limits current fast-charging of batteries. The closed system would eliminate the dangers inherent in letting untrained people move 100kwh of charged chemical danger out in the wild. It would be "as quick and easy as pumping gas" as far as the user experience. But it would not be "filling an empty tank with go-juice", and even the article doesn't say it would be.
The fluids would clearly have a replacement schedule, much like engine oil, and you would take your car in for that maintenance when the pump told you that the charging rate during your "fill up" was sub-optimal.
Much better than a true pump and nozzle arrangement.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
It is, because the 'recharging' occurs at the 'petrol' station long after you've left.
Its then pumped in to someone else's car.
If my math is right, you're off by nearly a factor of 10.
To replace every ICE passenger vehicle in America with an EV with double the battery capacity of the Nissan Leaf would increase annual US electric consumption by 40% not a 300% increase by replacing only a third.
Passenger vehicles in US incl SUVs = approx 250,000,000 (2006)
Nissan Leaf battery capacity is 24 kWH so double = 48kWh
Assume full charge every 3 days so annual # of fillups = 120
(The vehicle number is somewhat low but the charging and capacity numbers are high) .384 or 38.4%
Total electricity usage for EVs = 250000000 x 48 kW-hrs x 120 / yr = 1 440 000 000 000 kWh/yr or 1,440,000,000 MWh/yr
Annual US electricity usage for 2009 = 3,750,000,000 MWh/yr
Divide total projected EV usage / Annual current usage =
Not that's current USAGE not current capacity; having only a fraction of those EVs enabled with Vehicle-to-Grid in large population centers would give the grid enormous benefits for distributed storage. Businesses and manufacturing may not be so happy as the cheap or free nighttime power they've enjoyed would become a thing of the past.
Pain is merely failure leaving the body
Isn't this a kind of a fuel cell?
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 diesel. Oh, crap! My poor father. (Turns out that both tanks were supposed to be filled using the same hole.)
Insurance paid for the car to be disassembled, the parts cleaned and then reassembled. They had no problem accepting that as an accident, 'cos seriously, who on Earth would do something so stupid on purpose?
I really hope I'm not on track for a Darwin Award. But hey, I'm in software, and cars are hardware.
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.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
And one way or another, when you fill that canteen you either leave/trap a little air or waste some water due to overspill. In fact I bet you often do both.
And the word I meant to put in the subject was "Apocryphal"...
Not to be pedantic. Twice. 8-)
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
Yes, for now, real travel requires a "real" car. However, most car trips are short commute and shopping mall trips with 1 person in the car. Where electric would be more efficient than gas.
Electric will come when it's the most attractive alternative financially, i.e. when gas prices go high enough.
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.
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 rust (yeah as if GM can control rust...) etc.
http://en.wikipedia.org/wiki/Flow_battery
http://en.wikipedia.org/wiki/Vanadium
"The National Institute for Occupational Safety and Health (NIOSH) has recommended that 35 mg/m3 of vanadium be considered immediately dangerous to life and health."
"Vanadium traces in diesel fuels present a corrosion hazard; it is the main fuel component influencing high temperature corrosion."
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
the batteries leaked again!
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 retrieval and refilling procedure at fuel stations.
You can advertise in this sig from as little as £99.99 a month!
"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 apply power and run electricity in and make hydrogen and oxygen (or whatever).
However, due to the various engineering factors (flow resistance, phase transformations, electrical resistance etc....) they aren't often used in reversible mode. The perk of a flow battery is that if is designed to be used in reversible mode, and its engineered to avoid a bunch of these problems. Essentially on the continuum between batteries and fuel cells it's closer about right in the middle.
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.
See:
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 for a non-electrically heated house. This size unit would give impressive load level capability to the grid, and would be awesome for off grid use.
Going to a slurry increases the energy density, but possibly with problems with charging. How do you keep the particles the same size during the charge cycle. In many conventional cell batteries, differential plating on charge is often the limiting factor on the number of cycles.
In principle, the working solution could be filtered and the large chunks broken up. From the description of the press release, however the slurry has the consistency of light grease. Filtering would be problematic.
This may require periodic extraction and reprocessing of the working material. Still, this should be easier than rebuilding a battery.
Third Career: Tree Farmer Second Career: Computer Geek First Career: Teacher, Outdoor Instructor, Photographer.
Um, I think you missed the point. The important number is the amount of energy used for ICE transport. The number and capacity of brand x electric vehicle does not matter. I'm supposed to be working now so I won't go and look this up, but I suspect that 30% of the energy content of our transport fuel far outstripps all "alternative" generation capacity. IIRC, an article in the IEEE Spectrum way back in 1996 stated that replacing the average energy flux into gas tanks in the greater L.A. basin on a typical Friday afternoon would require about 100x the output of the Hoover Dam. Polywell fusion anyone? Sorry about the line breaks, don't know why they are not showing up correctly.
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Of course, one mitigating benefit is that electric motors weigh far less than gasoline-powered ones do, and are more efficient.
You're special forces then? That's great! I just love your olympics!
Ignore this, modded wrong.
for i in `facebook friends "=bday" 2>/dev/null | cut -d " " -f 3-`; do facebook wallpost $i "Happy birthday!"; done
Not at all - he made a clear mistatement or miscalculation. Yes, there is a hell of a lot of energy content in our liquid fuels but since a fairly small percentage actually moves the vehicle versus heating the engine, it's not a one-to-one replacement. A gallon of gasoline has more energy than a fully charged Nissan Leaf but I don't know any comparable street legal cars that'll get 100 mpg.
Pain is merely failure leaving the body
The batteries might bring the weight right back up and higher than an ICE vehicle however, for example the Lotus Elise vs Tesla Roadster. The Tesla weighs about 500lbs more.
However that uses relatively heavy (compared to other modern technologies) Li-ion batteries, Li-pos are much lighter, and I don't know how much this new battery type will weigh.
"When information is power, privacy is freedom" - Jah-Wren Ryel