MIT scientists create super-rapid lithium ion battery charging technology

It's a good news; one of problems with battries seems to be resolved.

Cannot wait to hear a major improvement of battery energy density that will recolve one major obstable of EV.

I am very pleased to hear of the forward thinking concerning EVs.  As my EV gets slower and slower, and goes on shorter and shorter trips and is making all sorts of whines; it sure could use a kick n the batteries! ;-)  By the time I get home and back it up to the chargers it is groaning and buzzing a lot.  Never was noisy at all.

I'm figuring on 3 or 4 Interstate batteries: hope they last 2 years!

It's good news but only for mobile phones and laptops at first.  That's the type of battery they are talking about.

I suspect it will be some more years before the technology makes its way into vehicles as the problems of power delivery are quite a challenge.

Regenerative braking will benefit first as the current and voltage are similar to those for accelerating.  Well, sort of.  If you think about the current required to accelerate a Prius from 0-100 km/h in 15s then that gives you x Amperes of current drain.  But you won't be able to recover more than this current during regenerative braking at the same rate (100-0 km/h in 15s).  If you were to try and capture the same total kinetic energy in 7.5s, you'd have to size the electric motors and wiring for 2x Amperes of current.  Obviously, they aren't going to do this so there will still be lots of occasions where the braking regeneration is less than ideal and power will be wasted in the brakes as heat.

The problem is worse for a charge station.  While it might be possible to build a new battery that has the extreme charge acceptance rate suggested, the rate at which the "nozzle" can deliver power to the battery is limited.  Say your EV has a 50kW motor and you cruise along for an hour at 10kW on a highway.  That means you've consumed 10kWh of electricity.  Expressed in pure energy, that's 36MJ (mega Joules). You pull into the "gas" station and connect the charge cable.  If you are going to put 36MJ of energy back into the battery in 1 hour (3600 seconds) you need to charge at 36,000,000 / 3,600 = 10,000 J/s (Watts).  If you are trying to do the same feat in 2 minutes then you need to charge at 36,000,000 / 120 = 300,000 J/s - 300kW.  That's a helluva lot of juice.  To keep the current to something that can be delivered by a cable that doesn't weigh a ton, say 30A, you'd need to be charging at 10,000V

You are never going to find a EV charge station that allows the public to handle a cable carrying 10kV at 30A in the rain...

I think one of potential idea of shortening chaging time is replace whola batteries at the station - changing rather than charging.

Of course, there are many difficult issues to make it happen, such as all battery values and quality has to be uniform, etc. But, faster discharge, much slower charge are current battey's characteristic.

If either auto manufacturers of energy company would own all batteries, and drivers rent them at some uniform price, changing batteries may be possible.

Not a bad idea...I think.

Thinking just of the logistics, I wouldn't want one of those cars...

It's bad enough changing a 12V starting battery that is reasonably accessible, weighs about 20kg and has just a retaining clamp and two terminal bolts to undo to extract that battery.  Lithium batteries have higher energy density and are made of lighter stuff than lead but a 240V 40Ah battery pack (to deliver our notional 10kWh of juice for a 1 hour drive) is still going to be a big heavy beastie.  The average lithium cell is about 3.6V so that's a pack of 67 40Ah cells.

In reality the battery is going to have to be bigger than that as we said we'd fit a 50kW motor to give us decent acceleration and top speed or for carrying passengers.

To make the battery swap station work we'd have to make the pack a drop-in solution (assuming you can "drop-in" something weighing ~50kg).  This means not having to do up terminal bolts but something like a big laptop battery that you press a button and it just pops out and you push in a new one and it clicks into place.  Even with a 67 cell lithium battery, we'd have to fit connectors that won't make a bad connection when a bit grubby (these batteries are gonna be sitting in some garage forecourt) and catch fire when you step hard on the accelerator and draw 200A though them.

Then there's the trust thing... How do I know the garage is going to sell me a fully charged battery or one that hasn't got a duff cell or two. 

In my view the only way we're going to get useful EVs with sufficient range, power and current day convenience is with hydrogen fuel cells.  Honda are trialing a fuel cell car in the US and the basic refueling infrastructure can be adapted from LPG stations that are already in service.  The tank can be filled up just as quick as LPG cars of today and you make the hydrogen with renewable electricity.

Quote:

Originally Posted by AccordGuy 

 

Honda are trialing a fuel cell car in the US and the basic refueling infrastructure can be adapted from LPG stations that are already in service.  The tank can be filled up just as quick as LPG cars of today and you make the hydrogen with renewable electricity.

Speaking of which...the guys at Top Gear got to test out the Honda FCX Clarity

Everyone knows hydrogen is clean, but a problem is a tank to hold compressed hydrogen. It iiiiiis expensive.

I was simply saying the tank to hold compressed hydrogen is expensive, and not hydrogen itself.  Fuel cell is also expensive, but nano-carbon technology may change whole fuel sell situation.

I wonder if EV is that clean..... of course, vehicle itself is clean, but 50% of electricity is produced by burning coal as of 2006 in the USA. (If I am wrong, please correct me.)  And, EV requires charging electricity.....

TOYOTA says they cannot increase production of batteries...... This is for hybrid, and not for 100% EV.

This indicates another problem. Rapid increase of battery production/consumtion will not only use up raw materials, but also criates recycling problem. Though some raw material could be re-used, what do they do with astronomical amount of used batteries?

Very good!!  At least one of problems are being studied with positive forecast, but it may be a bit too early to say no problem while engineer are studying the possibilities of remanufacturing these batteries. And, how long it will take is another issue.

I hope I am not sounding too negative; I just cannot fully fall in love with EV yet, though it is one of choices we currently have.

Quote:

Originally Posted by dana1981 

 

That depends what you're comparing it to.  As discussed in the hydrogen cars wiki, 96% of our hydrogen comes from fossil fuels (mainly natural gas).  It's cleaner than gasoline, but not as clean as electric cars.

I was thinking in the future - when fuel cells are cheap, hydrogen is made from electrolysis of water from wind/solar power.  You're right that most of the hydrogen would be made now from cracking hydrocarbons which isn't ideal.  If renewable isn't enough, then nuclear is the next best option. 

But EVs are (and are likely to remain) impractical for anything other than urban commuting due to the size of the batteries and speed of recharge power delivery issues (even if the speed of charge acceptance can be increased). 

The cost of implementing a hydrogen forecourt service can't be that high as the UK and most of Europe have already implemented LPG networks on their major road networks for a small minority of cars (compared to diesel and petrol).  My brother-in-law drives a LPG car as his daily driver and that includes crossing the country to Wales on a regular basis.

i agree dana. the industry is in the state internal combustion was in the first decade of the last century, with all sorts of strange designs. who knows, we might even have ended up with stirling engines if things had gone differently in the early years.

i saw this rapid charging thing, it will be a massive boost, as it removes the second biggest problem after weight.

how about compressed air for town cars like tata are pioneering? will that cut in on or complement the electric car thing?

Quote:

Originally Posted by dana1981 

 
 

Well I have to disagree with you here.  You're talking about a future which is likely decades away when fuel cells are cheap and electrolysis is the prefered option, but then talking about today's battery technology.  That's not a fair comparison.

 

When I meant "the future", I was thinking about circa 10 years.  It takes 10 years to build a nuclear power plant.  It's projected in Europe that 20% of electricity demand will be met by renewables by 2020 (ok that's 11 years). If Honda are aiming to lease to the public 100-200 of the FCX fuel cell cars at $600 a month this year (2009) then I'd expect them to be in mass production at the same price or less within 10 years.  If a government mandates it, the construction of a hydrogen re-fueling network on the major highways will take less than 10 years to complete as existing sites can be used and planning permission given to encourage it.  Supermarkets often build their own petrol station on the same site to bring in the shoppers.  If planners tell them "you can build your supermarket and gas station only if you include a hydrogen pump" then you'll soon get some stations.  This is true of old petrol stations too.  At the moment supermarkets are locked in a battle to buy the independent stations up and convert them to mini-marts, so there's scope there too.

Perhaps where I'd see the rapid charge EV gaining practical traction is in electric bikes.  The power requirements (total) are much lower for bikes to achieve the range, speed and load capacity that people expect (pizza delivery) and you might be able to keep the 3 minute recharge at a station down to something that the grid and the handler of the "refueling" cable can safely manage.

The problem of speed of bulk electrical delivery is not one that is going to be solved easily.  The best way to deliver very large bulk energy in a short time with relative user safety is a chemical store (hydrogen, petrol, diesel, butane).  Each has huge stored energy that can be transported and delivered quickly and safely to and at a re-fueling station.  The grid is a streaming power source.  Electricity flow is good for sustained (relatively) low rate energy delivery.  By it's nature, it is not easy to store in bulk or move in bulk quickly.  In it's raw state (charge) it is dangerous to handle and store (we are conductors, air is a conductor, a vacuum is a conductor for the 25kV electron beam of a TV).  I'd use the example of a stick of dynamite.  Dynamite is a chemical store of huge potential energy release in a very short time but is relatively safe to handle and move.  The same electrical energy delivery potential in a portable form would be lightning in a bottle.

I did overlook one way that the bulk of electrical charge could be safely delivered to the ultra-fast charge battery... room temperature superconductors.  This gets around the problem of having to use very high voltages in the refueling cable.  With a superconducting cable, you can deliver unlimited Amps with no heating or loss and so you can do it at a low and safe voltage for users to handle the cable.  However, practical, flexible, room temperature superconductors are still a science fiction and while the hydrogen infrastructure would be costly and time consuming to build, at least it is based on technology that exists and can be deployed now.

There's no doubt that the ultra-fast charge battery will revolutionise our lives.  I just think it will be in laptops rather than EVs.

Yes, EV is absolutely wonderful, but there are few things we should not forget.

Electricity is one of the most expensive energy now. And, what makes this energy very different from others like fossil emergy, hydrogen, is it cannot be preserved in tank or some facility. It is a stream of energy that need to be continuously supplied from generator. When generator stops like natural disaster, everything stops immediately.

Because of such characteristics, supply capacity has to be nearly the maximum consumption level - perhaps middle of summer in north hemisphere. No "black-out" is accepted under any condition to EV. There must be a study if all or some large percentage of vehicles are convereted to EV, how much more power plants do we need, plus all necessary infrastructure.

Battery technology is advancing very fast, but still under development. The ultra-fast charging capacity by nano-carbon technology did not have cost indication. Nano-carbon tube was ultra expensive at least a couple of years ago - 1 gram (1/2.8 oz) costs $800. I don't know current market price, but it is still super expensive. Also, production of nano-carbon tube needs significant amount of electricity, unless some other medhod was invented.

Anyway, I think it is essential not to limit possibilities, and carefully consider all pros and cons to use the best of each energy. It may be wrong to look for new technology that will replace everything we have now.