Electric cars are a pipe dream

[billvon]

The Lithium Ion micro batteries are better - a cellphone battery would have the juice to jump start a dead car battery

The electrodes alone would not carry enough current to do that.

and then recharge in seconds.

There are a lot of technologies that can do that but li-ion isn't one of them. LiFePO4 for example. They are used by Formula 1 racer hybrid systems; they can accept hundreds of amps, although they pay for it in lower energy capacity.

 

[Trippy]

The electrodes alone would not carry enough current to do that.



There are a lot of technologies that can do that but li-ion isn't one of them. LiFePO4 for example. They are used by Formula 1 racer hybrid systems; they can accept hundreds of amps, although they pay for it in lower energy capacity.

Did you read the article I linked to? The details are right there. Microbatteries are a major breakthrough in Lithium Ion cell technology, and the breakthrough is in the cell structure. The break the norms you're referring to, the trade-off between power and capacity.

 

[billvon]

Did you read the article I linked to? The details are right there.

Yes, I did. And again, the electrodes on a cellphone battery are insufficient to "jump start a dead car battery." (And are also the wrong voltage to boot.) It's not a limitation of the chemistry, it's a limitation in electrode sizes on cellphone batteries.

 

[Trippy]

Yes, I did. And again, the electrodes on a cellphone battery are insufficient to "jump start a dead car battery." (And are also the wrong voltage to boot.) It's not a limitation of the chemistry, it's a limitation in electrode sizes on cellphone batteries.

:sigh: :facepalm: That's your complaint? I'm fairly sure they don't mean you could literaly pull one of these batteries out of your cellphone and use it to jumpstart a car, however, with appropriately sized terminals, you could use a battery the size of a cellphone battery to jumpstart a car.

Incidentally, I discovered one day, the hard way, that you have the same limitation with jumpstarter cables (except there it's the cable cross section that matters). Cables that work when your battery is only mostly dead won't neccessarily work when your battery is truely dead.

 

[Trippy]

What support can you cite for those two claims? I find it very hard to beleive either.

Common lead acid car batteries will supply, with little terminal voltage drop more than 100 "cranking amps" for several seconds.* I think that is impossible for cell phone battery for even 0.1 seconds (mainly due to polarization effects at the much smaller electrode plate areas). If your car battery is dead and you even disconnect it (so all energy from cell phone battery is used for the "jump start") then I don´t think it will jump start you car and if it does, it will self destruct - not be rechargable.

What is the short circuit current after 0.5 seconds of a cell phone battery, assuming it has not yet exploded.

* I think the one in wife´s 1.4 liter engine car is rated for 240 cranking amps.

The support I have for those two claims is the article I linked to in post #3031, which in turn is supported by a paper accepted March 13 of this year, and published April 16 of this year. Perhaps you should read that, keeping in mind the effects of surface area upon reaction rates and why while a 2kg lump of coal might be nearly impossible to light, 2kg of coal dust would be explosively combustable.

 

[billvon]

:sigh: :facepalm: That's your complaint? I'm fairly sure they don't mean you could literaly pull one of these batteries out of your cellphone and use it to jumpstart a car, however, with appropriately sized terminals, you could use a battery the size of a cellphone battery to jumpstart a car.

Three in series, with appropriate (large) tabs, yes. You could do that with 18650-sized A123 cells right now (about the same volume as a cellphone battery.) They'll supply hundreds of amps.

Incidentally, I discovered one day, the hard way, that you have the same limitation with jumpstarter cables (except there it's the cable cross section that matters). Cables that work when your battery is only mostly dead won't neccessarily work when your battery is truely dead.

Yep. Most jumper cables are good enough to charge a mostly dead battery and provide some current to help crank the starter, but not good enough to crank the starter alone. One of the reasons that 42 volt car systems have been pushed for a long time - thinner wire required, less danger of overheating.

 

[Billy T]

The support I have for those two claims is the article I linked to in post #3031, which in turn is supported by a paper accepted March 13 of this year, and published April 16 of this year. Perhaps you should read that, ...

Thanks for the 3031 link. It supports your claims but tells nothing as to how, except like you, they suggests that there is much more surface per pound in tiny particles. That is true and the surface available for reaction is what mainly limits the power level possible; however, cranking a car for 3 seconds with 120 Amp at 12 Volts is 3x1440 = 4320 joules. To get that requires a certain number of litium ions to be reacted (even ignoring the internal losses). (Too lazy to compute and not even sure of the reaction elements.) What mass is that? Less than a cell phone´s battery mass?

Not related to your claim is the practical consideration that there have been many efforts with "micro-pore" electrodes and AFAIK, all fail to achieve a practical number of charge/ recharge cycles as diffusion etc. destroy the micro surface structure or it is simply poisoned by side reaction products.

Yes, I would like to read the paper published April 16 of this year. Do you have more complete reference to it? An on line links or a few quotes from it would be great. thanks again.

 

[Trippy]

Three in series, with appropriate (large) tabs, yes. You could do that with 18650-sized A123 cells right now (about the same volume as a cellphone battery.) They'll supply hundreds of amps.

Right, but that was only half the claim made in the article. How long would they take to recharge?

In fact, the paper that was published compares them to A123 cells. The PPV Nature article compares the performance of this new design with existing designs, including A123. The work itself builds on work done in 2011. The problem, as I understand it, is that making the active material a thin film decreases charging time, but also reduces the amount of active material, and therefore capacity. The breakthrough in 2011 was wrapping a thin film into a 3D structure which vastly improved charge times (the 2011 article claims 10-100 times faster). In the paper published in 2011 they claim "Rates of up to 400C and 1,000C for lithium-ion and nickel-metal hydride chemistries, respectively, are achieved (where a 1C rate represents a one-hour complete charge or discharge), enabling fabrication of a lithium-ion battery that can be 90% charged in 2 minutes."

I get the overall impression that the work that was done in 2011 was to develop a fast charging Cathode, and this work published in the last couple of days is building on it by producing a similarly designed, and similarly fast charging anode. The net result being that the potential now exists for electric cars with batteries that charge in about the same time it would take you to pump a full tank of gas - assuming it can be commercialized.

Yep. Most jumper cables are good enough to charge a mostly dead battery and provide some current to help crank the starter, but not good enough to crank the starter alone. One of the reasons that 42 volt car systems have been pushed for a long time - thinner wire required, less danger of overheating.

I was annoyed at the time. It wasn't something I had ever thought of, but when it was pointed out to me it was like "Well duh! Of course!"

 

[Trippy]

Thanks for the 3031 link. It supports your claims but tells nothing as to how, except like you, they suggests that there is much more surface per pound in tiny particles. That is true and the surface available for reaction is what mainly limits the power level possible; however, cranking a car for 3 seconds with 120 Amp at 12 Volts is 3x1440 = 4320 joules. To get that requires a certain number of litium ions to be reacted (even ignoring the internal losses). (Too lazy to compute and not even sure of the reaction elements.) What mass is that? Less than a cell phone´s battery mass?

Not related to your claim is the practical consideration that there have been many efforts with "micro-pore" electrodes and AFAIK, all fail to achieve a practical number of charge/ recharge cycles as diffusion etc. destroy the micro surface structure or it is simply poisoned by side reaction products.

Yes, I would like to read the paper published April 16 of this year. Do you have more complete reference to it? An on line links or a few quotes from it would be great. thanks again.

University of Illinois release: Small in size, big on power: New microbatteries a boost for electronics
University of Illinois 2011 release: Batteries charge very quickly and retain capacity, thanks to new structure

I'll have a hunt and see if I can find some more.

 

[billvon]

Right, but that was only half the claim made in the article. How long would they take to recharge?

Tens of seconds. They accept charge rates up to about 120C, so that's about half a minute.

I get the overall impression that the work that was done in 2011 was to develop a fast charging Cathode, and this work published in the last couple of days is building on it by producing a similarly designed, and similarly fast charging anode. The net result being that the potential now exists for electric cars with batteries that charge in about the same time it would take you to pump a full tank of gas - assuming it can be commercialized.

Yep, that's the holy grail of battery manufacturers. But again, that's been promised by lab cells for the past 10 years. Hopefully one day one of these lab cells will actually live up to the claims about them.

Another issue is how you actually get that much power. If you really have a 400C rate battery, for a battery like a Tesla's that's 34 megawatts. That's how much power a small town takes. You might be able to put a few such chargers in near electrical substations but no normal electrical distribution system will be able to handle such a charger.

 

[Trippy]

Yep, that's the holy grail of battery manufacturers. But again, that's been promised by lab cells for the past 10 years. Hopefully one day one of these lab cells will actually live up to the claims about them.

Another issue is how you actually get that much power. If you really have a 400C rate battery, for a battery like a Tesla's that's 34 megawatts. That's how much power a small town takes. You might be able to put a few such chargers in near electrical substations but no normal electrical distribution system will be able to handle such a charger.

Unless you, for example have a large bank of these batteries (how big are the UST's at Gas stations?), that are capble of fast charging the cars, and therefor providing buffer, that are themselves charged at a slower rate.

 

[billvon]

Unless you, for example have a large bank of these batteries (how big are the UST's at Gas stations?), that are capble of fast charging the cars, and therefor providing buffer, that are themselves charged at a slower rate.

You still have the problem of total energy. For example, let's say you have a 100kW service (as a large commercial space might have.) That would allow the charging of an average of one Tesla sized car per hour, so say 24 or so during a day. Can a charging station that services only 24 cars a day make money, assuming all the battery replacements you'd need? You can go to a larger feed but that's going to get expensive fast. Currently the largest chargers around (the Tesla superchargers) max out at 100kW.

You also have the issue of power delivery. 34 megawatts at 600 volts (generally the highest voltage you can work with assuming mechanical connections) is 57,000 amps. The thickest wire out there is around 1500 MCM wire; that cable will weigh a pound an INCH and carry 600 amps or so. You'd need 94 of them in parallel, resulting in a cable that would be bigger than a sewer pipe and weighing thousands of pounds.

This isn't really a problem in the short term; a battery that will accept power at a 400C rate will certainly accept it at the 1C rate that a charger like the supercharger can deliver, so it can be charged over the course of an hour at a standard charger. But it does mean that the 400C rate is, right now, overkill for most applications. A battery that could accept charge at 10C, discharge at 10C and last 5000 cycles would work very well in most EV applications; going higher than that will result in diminishing returns, at least until we figure out how to supply that much power to a battery.

 

[Trippy]

You still have the problem of total energy. For example, let's say you have a 100kW service (as a large commercial space might have.) That would allow the charging of an average of one Tesla sized car per hour, so say 24 or so during a day. Can a charging station that services only 24 cars a day make money, assuming all the battery replacements you'd need? You can go to a larger feed but that's going to get expensive fast. Currently the largest chargers around (the Tesla superchargers) max out at 100kW.

You also have the issue of power delivery. 34 megawatts at 600 volts (generally the highest voltage you can work with assuming mechanical connections) is 57,000 amps. The thickest wire out there is around 1500 MCM wire; that cable will weigh a pound an INCH and carry 600 amps or so. You'd need 94 of them in parallel, resulting in a cable that would be bigger than a sewer pipe and weighing thousands of pounds.

This isn't really a problem in the short term; a battery that will accept power at a 400C rate will certainly accept it at the 1C rate that a charger like the supercharger can deliver, so it can be charged over the course of an hour at a standard charger. But it does mean that the 400C rate is, right now, overkill for most applications. A battery that could accept charge at 10C, discharge at 10C and last 5000 cycles would work very well in most EV applications; going higher than that will result in diminishing returns, at least until we figure out how to supply that much power to a battery.

What's the volume of the battery in a Tesla?

 

[Trippy]

Some gas stations (I have no idea of the proportions) have 67,000 gallons of UST storage for petrol.

C-net suggests that the battery of the Model S occupies about 14 cubic feet.

This suggests that, problems with the architecture involved in transferring the energy from the batteries to the cars to one side for one moment, simply by replacing the volume occupied by UST's with batteries, a service station could store enough charge for 638 Tesla model S's. You discharge 0.16% of the batteries capacity in a few minutes, and then replace it gradually through the rest of the day. It seems to me that the recharge rate only needs to match the time averaged drain which is what, 4.25% per hour if we assume that during the course of the day it uses all of its charge.

 

[billvon]

SThis suggests that, problems with the architecture involved in transferring the energy from the batteries to the cars to one side for one moment, simply by replacing the volume occupied by UST's with batteries, a service station could store enough charge for 638 Tesla model S's.

Agreed, with the caveats that the battery alone would cost $32 million, need to be changed about once every ten years (hence a $3 million a year expense for the owner) and could still charge only 24 cars a day on average with a 100kW feed. You'd have to charge $350 a charge just to maintain the battery bank.

 

[Billy T]

Unless you, for example have a large bank of these batteries (how big are the UST's at Gas stations?), that are capble of fast charging the cars, and therefor providing buffer, that are themselves charged at a slower rate.

Perhaps a spinning electric generator would be cheaper. I worked on the margins of the "controlled fusion" problem at APL/JHU, which back then was mainly funded by the US Navy, for about a decade.* We got Navy to give us an old generator from a mine sweeper. I had been to visit the "stellerator" at Princton, which at the time was, I think, the most serious large scale effort at controlled fusion. Their magnetic confinement required about same power level for less than a second as the town did. They got it from a large spinning generator.

The Navy´s (small) motor (large) generator, which we never used, was about 10 or 12 feet in diameter and needed a separate room adjointing our ground floor lab area to be built. To avoid being too ugly, stuck on the front of the three story building, it was mainly under under ground with generator lowered thru the flat roof. We did get some use of the room, which was not connected to the building´s ventilation system, during the year or so we explored a pulsed peak-power laser runing on hydrogen-cynaide. Fortunately, I never worked on that so very rarely went into that new room, which then had a newly added, separate, high capacity fan ventulation system.

BTW: What are USTs - I´m guessing the T is for transformer.

* Navy did not expect us to solve the Controlled Fusion problem. It often uses the brain power at APL to help it over see contracts of major Navy projects. They wanted our small group (4 Ph.D.s) to have real hands-on experience in the field. Navy expected to let the contract for a fusion powered air craftcarrier in about 10 years.

For ~60 years, the solution to the problems of controlled fusion has remained expected in "about ten years from now" :bugeye:

 

[Trippy]

BTW: What are USTs - I´m guessing the T is for transformer.

Underground Storage Tanks

 

[Trippy]

Agreed, with the caveats that the battery alone would cost $32 million, need to be changed about once every ten years (hence a $3 million a year expense for the owner) and could still charge only 24 cars a day on average with a 100kW feed. You'd have to charge $350 a charge just to maintain the battery bank.

If we're only charging 24 cars a day, we can reduce the battery size, and therefore replacement cost.

The setup I proposed would charge 638 Tesla Model S's per day. If we're only charging 24 per day, that's 3.7% of the capacity, and therefore the cost. That reduces the cost of replacing a battery to what, $13 per charge for the owner?

 

[KitemanSA]

Think flywheel, not battery. Beacon Power is one option. Pentadyne Power is another.

 

[Billy T]

Think flywheel, not battery.

Super- Flywheels are a high energy density way, perhaps even soon and economical way, to store kinetic energy but getting huge power surges from them is much more costly than getting that power from a spinning generator as you still need that high power capacity generator to convert the stored KE into electric power. - Just let the generator be both the energy storage device and the converter of KE into electric power. - No need for two separate units of approximately equal cost.

I have long argued that super flywheels should power urban busses as they stop often and could get from an electric contact pole some re-spin at stops. They would not be tied to trolley lines and could make detours if road was blocked by fire etc. Plus unlike batteries they are "good as new" after 100, 000 charge/ recharge cycles and of course release no CO2 or NOx etc. in the city. In Sweden more than 30 years ago there was a city bus powered by a simple primitive iron flywheel recharged at stops. To avoid excessive gymbal costs, perhaps only used on routes with small slope hills.

I knew about Beacon´s flywheels some years ago, but then read nothing so I searched:

The DOE picked a winner in the now bankrupted Beacon Power flywheel energy storage, says its new owner, Rockland Capital. Changes in electric power regulation can have a disruptive effect, unleashing billion-dollar markets overnight. One example of such a new market is the one being created by the new FERC Order 755, about to take effect in the United States in October of this year.

“The price of renewable energy technologies will continue to drop, while the price of natural gas will rise,” said commission member John Norris of the U.S. Federal Energy Regulatory Commission (FERC) ... The FERC rule is designed to enable much more solar and wind on the US grid by offering better compensation for providers of frequency regulation that provide the faster-ramping storage technologies needed to do that. ... The grid now needs frequency regulation that can ramp up in seconds.

One company that trail-blazed exactly the kind of faster storage that the new FERC rule incentivizes had spent $200m designing, patenting and building a fast-responding 20 MW capacity mechanical balancing system that can ramp up in seconds, based on familiar flywheel technology. But it’s bankrupt. Bankruptcies are usually an indication that a company is offering a product that is behind the times: something the market no longer needs. But in the case of Beacon Power’s bankruptcy the opposite has thought to ocurred largely because it was ahead of its time, ...

For those of you who may not know much about Beacon Power it had been the recipient of $43m from the U.S. Department of Energy (DOE) Section 1705 loan guarantee programme for the world’s first ever flywheel energy storage project it built in Stephentown, New York.

My older friend and colleague at APL/JHU, Dan Rabenhorst, was testing fiber based super flywheels of his design to destruction 35 years ago. Both radial “brushes” and circular wound designs running in vacuum. One interest and consistent results was that the fibers melted and or became dust in a flash of white light when they hit the chamber walls. Huge production of surface energy and or phase change absorbed much of the stored energy. Just the needed vacuum chamber provides good safety.