Electric cars are a pipe dream

[Billy T]

...
The problem is that battery chemistry is not amenable to miniaturization like processors were. There are only so many electrons in lithium ions, and you can't miniaturize electrons. ... They really don't. You can't miniaturize electrons, so as long as you are storing them chemically you're going to run into that limit. ...

Your point is completely correct but not expressed well. The chemical energy is not stored in the electrons. It is the difference in the before and after binding energy of the "fuel" and "ash" compounds of the reaction. Lithium is best fuel as the weight per fuel atom is the least of all non-gases. Only hydrogen is better but it needs a heavy thick-walled pressure tank to hold as a gas or well insulated, heavy, cryogenic tank, if a liquid.

Your main mass is the atomic atoms or molecules (not the electrons) and there is no better one than Lithium on an energy per pound basis - I.e. no future chemistry will ever be better on that basis but there may still be some weight reduction possible in the battery cases, electrode surface to mass ratios etc. but not in the basic chemistry. I doubt that even a 50% improvement in KWH per pound is still possible over best Li-ion batteries that now exist for batteries that are small compared to the car.*

* As the case mass is roughly proportional to the surface area and the stored energy is proportional to the volume, if battery were bigger than the car, then it could have a better stored energy per pound ratio - but I would not want to any where near it when it fails - explodes. This surface to volume effect on the stored energy to weight is one more reason why the suggestion that one should have separate cells, wired up in series at the gas station, each in its own package, is silly.

 

[billvon]

Your point is completely correct but not expressed well. The chemical energy is not stored in the electrons. It is the difference in the before and after binding energy of the "fuel" and "ash" compounds of the reaction. Lithium is best fuel as the weight per fuel atom is the least of all non-gases. Only hydrogen is better but it needs a heavy thick-walled pressure tank to hold as a gas or well insulated, heavy, cryogenic tank, if a liquid.

Agreed - but the limit is set by the fact that you can recover, at most, one electron from every elemental ion in the battery. (Which is where Faraday's Constant comes from.) I use this constant as a basic sanity check when people propose their new "wonder battery" that can somehow recover ten Faraday constants worth of charge from one mole of active material. While it's theoretically possible to store two Faraday's worth of electrons in one mole of elemental ions the odds are very, very low that this will ever be practical due to the potentials involved.

Your main mass is the atomic atoms or molecules (not the electrons) and there is no better one than Lithium on an energy per pound basis - I.e. no future chemistry will ever be better on that basis but there may still be some reduction possible in the battery cases, electrode surface to mass ratios etc. but not in the basic chemistry. I doubt that even a 50% improvement in KWH per pound is still possible over best Li-ion batteries that now exist for batteries that are small compared to the car.

While the basic reaction isn't going to improve much, Li-silicon will give us another 10% or so (based on voltage improvements rather than increased coulombic capacity) and packaging/separator/safety improvements will give us some incremental improvements in weight and volume as well. But they will plateau at some point; I agree that they won't get much above 1.5x what we have now (if that.)

 

[Billy T]

Agreed ... While the basic reaction isn't going to improve much, Li-silicon will give us another 10% or so (based on voltage improvements rather than increased coulombic capacity) ...

I assume you are correct on that too, but bet Li-Cl reaction has even greater voltage gain /difference, but again what matters most is the energy yield per pound. That is why, on that basis, nothing chemical is ever going to be better than Li-ion battery.

 

[billvon]

but again what matters most is the energy yield per pound.

I think the three things we care about are:

joules per kilogram (lighter batteries)
joules per liter (smaller batteries)
joules per dollar (cheaper batteries)

Of the three the last is arguably the most important right now, since we have electric cars out there that can go 250 miles and recharge in half an hour. That's good enough for 99% of the people out there; they just can't afford the cost of the battery.

 

[Grumpy]

The problem is that battery chemistry is not amenable to miniaturization like processors were.

Ah, but a flow battery is. The savings in weight on a flow battery are obtained because you have separated the cell and it's fuel. So instead of having to carry the entire weight and cost of a sufficiently large lithium battery(for power AND range)it carries a fuel cell sized to provide sufficient power and fuel sufficient to provide a longer range. The fuel and lighter, smaller cell are lighter than the required excess battery that would provide the same range. Add in large high power capacitors to handle momentary high peak loads and the fuel cell can be made even smaller to provide cruise power plus a bit to keep the condenser topped off. Even lithium batteries are heavier than the electrolite in them and if that electrolite were to be replaceable you have saved the weight of the additional lithium in that second battery, third battery, fourth battery

Then there is nano-texturing of the anodes and cathodes. Electrons are tiny little things and a smooth plate of metal can interact with a set number of them on it's surface. But nano-texture that surface and you can increase it's area by some large factor, increasing it's capacity/power by the same factor. LiFePo nano batteries have already been developed taking advantage of this fact. I have personally witnessed the doubling and tripling of capacities in several chemistries including lithium just in the last decade or so. There's no reason to think it would not have exponential effects on any battery/fuel cell chemistry and construction, especially those(like flow batteries)where the anodes do not play a chemical role in the reaction, therefore suffer little wear or disintegration common to most battery chemistries.

Flow batteries require external chemical reprocessing facilities.

Some chemistries are reversible by adding electricity to the cell, in effect running the process in reverse(it's one of the things that distinguish the flow battery from being called a fuel cell). It is true that all extant flow batteries are in industrial power facilities, but the same was true of steam, gas and diesel power as well. Flow batteries or fuel cells(also in industry before in cars)are the two technologies that could actually improve our cars in terms of ease of use and reduction(to ZERO)in emissions. No battery chemistry can compete with either one in range or cost and any battery gives up a weight advantage due to duplication of mass.

Here's a short thought experiment.(I make a bunch of simplifying assumptions, I'm just illustrating the principle I'm talking about).

I have an electric car and I am choosing a power system. I have ten pound lithium batteries that fully power the car with a range of ten miles. I want a pack that will give me one hundred miles, so my pack weights 100 pounds. Each battery has 7 pounds of Lithium and three pounds of "fuel".

I also have a ten pound flow battery that fully powers the car, at any one time there is three pounds of "fuel" in the FB and that will give me ten miles of range. I want one hundred so I add another 27 pounds of fuel. My power supply weights 37 pounds. Since I don't mind a little extra range I make up the difference with 63 pounds of fuel, giving a total range of over 300 miles. A hydrogen fuel cell is even more effective, but hydrogen is nasty stuff(pressures/temps/flammability), electrolite would be at near atmospheric pressure and normal temps and not so nasty.

Note that even if the "fuel" in the FB is only a third as effective or weighted three times as much it could equal the battery in range and cost one tenth the material costs of the battery.

Grumpy

 

[KilljoyKlown]

Grumpy

Do you have any good links on this subject. I like what you've said about it.

 

[Grumpy]

I used to, but between the time I was involved in the homemade electric car hobby, the RC aircraft hobby and now have been several nuclear level computer meltdowns and I haven't been to them in years. I saw where A123 was going bankrupt, they made LiFePo4 nano-tech lithium cells. I think they were broken up into several pieces with the cordless tool and auto divisions being sold off to Dewalt and some car parts consortium.

Google "Flow battery", when I was following that the only installations were as buffers for wind farms in one of the Norse countries. They surely have improved since then, but I'm not current. The Wikipedia article I cited has some good info. Fuel cells and flow batteries have several similarities, it is mainly a difference in fuels(hydrogen and oxygen for fuel cells, reversible, two charge state electrochemical reactants in flow batteries), it is only the nastiness of hydrogen that makes flow batteries more attractive. It's an idea worth looking in to, steam was used for decades before the first practical and usable steam car was built, the same could be the history of flow batteries, they do have advantages.

Grumpy

 

[billvon]

Ah, but a flow battery is. The savings in weight on a flow battery are obtained because you have separated the cell and it's fuel. So instead of having to carry the entire weight and cost of a sufficiently large lithium battery(for power AND range)it carries a fuel cell sized to provide sufficient power and fuel sufficient to provide a longer range.

If you are talking a flow battery (an electrochemical device) they are all much lower energy density than current lithium-ion batteries by about a factor of 8. A Leaf battery will blow any flow battery away - which is why no one uses them for transportation. And that includes the savings from separating the electrolyte from the cell itself.

If you are talking a fuel cell, now you're on a different topic. A device that converts fuel to energy is indeed a good idea; every car on the road today has one. They work well for several reasons:

1) In most cases one of the reactants is available in the atmosphere (oxygen.)
2) In most cases the waste products can be exhausted to the atmosphere (water, CO2)

Those two factors make fuel based engines considerably lighter than things like batteries (flow or otherwise) and allow longer operation on a given amount of fuel. Hydrogen fuel cells are a promising idea although the problem of hydrogen storage has not yet been addressed. Methane storage is easier, and a direct methane fuel cell or a fuel reformer might work well there.

The fuel and lighter, smaller cell are lighter than the required excess battery that would provide the same range. Add in large high power capacitors to handle momentary high peak loads and the fuel cell can be made even smaller to provide cruise power plus a bit to keep the condenser topped off. Even lithium batteries are heavier than the electrolite in them and if that electrolite were to be replaceable you have saved the weight of the additional lithium in that second battery, third battery, fourth battery.

You cannot replenish the electrolyte in a lithium ion battery and restore capacity; the lithium is physically transferred to one of the electrodes and this cannot be "flowed' away without replacing the electrode itself (which is part of the cell.)

Then there is nano-texturing of the anodes and cathodes. Electrons are tiny little things and a smooth plate of metal can interact with a set number of them on it's surface. But nano-texture that surface and you can increase it's area by some large factor, increasing it's capacity/power by the same factor.

You can do whatever you like to the plates, and indeed such texturing can improve power, cycle life or reliability. However, nothing you can do will increase energy capacity once you run out of charge carriers (lithium ions in this case.) And in flow batteries you still have exactly the same problems - you need 8 pounds of reactants for every pound of lithium ion battery you replace. You can improve the electrodes through nanotech and whatnot, but you cannot reduce the need for reactants.

Some chemistries are reversible by adding electricity to the cell, in effect running the process in reverse(it's one of the things that distinguish the flow battery from being called a fuel cell). It is true that all extant flow batteries are in industrial power facilities, but the same was true of steam, gas and diesel power as well. Flow batteries or fuel cells(also in industry before in cars)are the two technologies that could actually improve our cars in terms of ease of use and reduction(to ZERO)in emissions. No battery chemistry can compete with either one in range or cost . . . .

Lithium ion does, in fact, out-compete the flow battery in terms of range and cost, since no flow battery can accomplish what the Leaf battery can (for example) as limited as it is.

Here's a short thought experiment.(I make a bunch of simplifying assumptions, I'm just illustrating the principle I'm talking about).

I have an electric car and I am choosing a power system. I have ten pound lithium batteries that fully power the car with a range of ten miles. I want a pack that will give me one hundred miles, so my pack weights 100 pounds. Each battery has 7 pounds of Lithium and three pounds of "fuel".

I also have a ten pound flow battery that fully powers the car, at any one time there is three pounds of "fuel" in the FB and that will give me ten miles of range. I want one hundred so I add another 27 pounds of fuel. My power supply weights 37 pounds. Since I don't mind a little extra range I make up the difference with 63 pounds of fuel, giving a total range of over 300 miles. A hydrogen fuel cell is even more effective, but hydrogen is nasty stuff(pressures/temps/flammability), electrolite would be at near atmospheric pressure and normal temps and not so nasty.

OK. Now some real world numbers:

In reality your 100 mile lithium battery weighs about 800 pounds. Your 100 mile flow battery weighs 6400 pounds. To get to 300 miles now you are at 19,200 pounds. (For reference a city bus weighs about 25,000 poiunds.) That's with a zinc-bromine battery, which is currently state of the art when it comes to flow batteries.

Which do you choose for your family car? The 800 pound option or the 6400 pound one? Or perhaps the 19,200 pound one?

 

[elte]

I like the idea of the electric-internal combustion engine hybrid, but with only about a ten horsepower engine, even though I realize that the need for power and speed occurs in a feedback loop between the consumer and the car companies. The battery capacity would be much smaller, mainly to temporarily increase total horsepower (by a large degree, maybe up to 40hp for quicker acceleration). Servicing the small drive train would be much easier. This configuration could move fuel economy much closer to 100mpg.

 

[billvon]

I like the idea of the electric-internal combustion engine hybrid, but with only about a ten horsepower engine, even though I realize that the need for power and speed occurs in a feedback loop between the consumer and the car companies.

Sure, that could work, although if your goal is highway cruising at 60mph you need to make that about 30hp.

The battery capacity would be much smaller, mainly to temporarily increase total horsepower (by a large degree, maybe up to 40hp for quicker acceleration). Servicing the small drive train would be much easier. This configuration could move fuel economy much closer to 100mpg.

40hp (30kW) is on the very low end of what people consider drivable in the US, so you might have to increase that. You could indeed get to 100mph with average speeds of around 40mph; the Insight did it.

 

[elte]

Sure, that could work, although if your goal is highway cruising at 60mph you need to make that about 30hp.



40hp (30kW) is on the very low end of what people consider drivable in the US, so you might have to increase that. You could indeed get to 100mph with average speeds of around 40mph; the Insight did it.

Indeed, that is very close to what I was thinking with regard to the 100mpg and the 40mph. These cars would be for driving at slower speeds than what most people are habituated for. However, they should cost quite a bit less to purchase and operate.

The 40hp would feel about the same for acceleration if the car is much smaller, like I think it should be.

I like the hybrid idea because so many people don't have much opportunity to charge the battery from a power line.

 

[KilljoyKlown]

Indeed, that is very close to what I was thinking with regard to the 100mpg and the 40mph. These cars would be for driving at slower speeds than what most people are habituated for. However, they should cost quite a bit less to purchase and operate.

The 40hp would feel about the same for acceleration if the car is much smaller, like I think it should be.

I like the hybrid idea because so many people don't have much opportunity to charge the battery from a power line.

Somehow I don't think that will go over very big with the car buying public. But what if you had a small engine that worked only to charge the battery while you drove the electric car. If you started with a full charge, the small charging engine just might be able to increase the mileage range to an acceptable level and still give you over 100 mpg, in a reasonable sized car that can drive at highway speeds that are more acceptable.

 

[billvon]

Indeed, that is very close to what I was thinking with regard to the 100mpg and the 40mph. These cars would be for driving at slower speeds than what most people are habituated for. However, they should cost quite a bit less to purchase and operate.

The Honda Insight had a 67hp gas engine and a 13hp electric motor. It got around 100mpg at 40mph. It cost only $18,000. Its acceleration was pretty anemic, and it's doubtful you could make it much smaller/lighter; it was already one of the smallest two-seaters on the road.

It wasn't that popular and was eventually discontinued, to be replaced with a larger, more powerful four seater.

I like the hybrid idea because so many people don't have much opportunity to charge the battery from a power line.

I'd argue that most people have plenty of such opportunities. I've been riding electric bicycles/motorcycles for about 20 years and outlets are quite easy to find. It's the problems with range that cause EV owners so many headaches. Pluggable hybrids solve this problem by allowing a "backup" source of power.

 

[elte]

Somehow I don't think that will go over very big with the car buying public. But what if you had a small engine that worked only to charge the battery while you drove the electric car. If you started with a full charge, the small charging engine just might be able to increase the mileage range to an acceptable level and still give you over 100 mpg, in a reasonable sized car that can drive at highway speeds that are more acceptable.

That would improve hybrids with respect to the Chevrolet Volt on the market right now, in my opinion. With this type of configuration, the battery would still have the disadvantages of large size and expense, like presently in the Volt, so that the car could travel at 60mph for up to about 100 miles, but the energy efficiency would be less than with the much smaller car that I prefer. That's because a larger car needs more energy for accelerating and cruising compared to a scaled down version.

However, after the battery became discharged during a long drive, the car could still continue, but at only 30mph or so, unless the engine were the larger type the Volt uses. Once the destination were reached, the small type of engine would continue running to recharge the battery, or if line power were available, it could be plugged in. The car would need to be parked in an area with open outdoor air for safety.

The idea I have also permits the car to be recharged off the power grid, yet it would likely strain the electrical infrastructure much less because of the relatively small battery. I hope people can adopt the idea of slowing down, staying closer, and downsizing so that the idea I like could catch on out there.

 

[elte]

The Honda Insight had a 67hp gas engine and a 13hp electric motor. It got around 100mpg at 40mph. It cost only $18,000. Its acceleration was pretty anemic, and it's doubtful you could make it much smaller/lighter; it was already one of the smallest two-seaters on the road.

Indeed, it's still way too big and expensive compared to what I'd like from the pictures that I've seen of it, and the electric motor/car weight ratio was too small.

It wasn't that popular and was eventually discontinued, to be replaced with a larger, more powerful four seater.

I considered and looked a bit for a used first generation Honda Insight even though the one liter engine was still too big in a car that was to big for my desire.

I'd argue that most people have plenty of such opportunities. I've been riding electric bicycles/motorcycles for about 20 years and outlets are quite easy to find. It's the problems with range that cause EV owners so many headaches. Pluggable hybrids solve this problem by allowing a "backup" source of power.

That was good compared to how that the only place, besides mine, I was able to plug my electric bicycle in at, was my mom's house.

Around here, I was thinking of people who live in apartment complexes, and localities want assurance that extension cords are connected to ground fault interrupter outlets, so a lot of people would need electricians to change that unless they can do it themselves, though I had never worried about that myself. I think a plugability option of the car is good, however.

 

[Grumpy]

elte

Indeed, that is very close to what I was thinking with regard to the 100mpg and the 40mph. These cars would be for driving at slower speeds than what most people are habituated for. However, they should cost quite a bit less to purchase and operate.

Increase top speed to 45 and you could do 95% of the driving most people do in urban areas. Something slightly smaller than a smart is about as small as most Americans would feel comfortable in. Personally, I think that a small three wheeled(two in front)bicycle based single seater with a 20kw motor and a hundred mile range and 45 mph top speed would be the goal.

Grumpy

 

[billvon]

Increase top speed to 45 and you could do 95% of the driving most people do in urban areas. Something slightly smaller than a smart is about as small as most Americans would feel comfortable in. Personally, I think that a small three wheeled(two in front)bicycle based single seater with a 20kw motor and a hundred mile range and 45 mph top speed would be the goal.

How about a Twike? 90 mile range, max speed 53mph, 3 wheel bicycle (delta, not tadpole.)

 

[Grumpy]

billvon

How about a Twike? 90 mile range, max speed 53mph, 3 wheel bicycle (delta, not tadpole.)

Vehicles with one front wheel and two rears are inherently unstable in emergency maneuvers. If something is blocking your path you automatically brake and turn, two things that if done together guarantee you will suddenly become very familiar with the minute details of the road you are on, likely with your bike resting on top of you. The only stable Deltas are leaning trikes, usually a complication not worth the weight or complexity(but people still try to build them). A tadpole is stable in the same conditions.

Grumpy

 

[elte]

Increase top speed to 45 and you could do 95% of the driving most people do in urban areas. Something slightly smaller than a smart is about as small as most Americans would feel comfortable in. Personally, I think that a small three wheeled(two in front)bicycle based single seater with a 20kw motor and a hundred mile range and 45 mph top speed would be the goal.



Grumpy

Indeed, the Smart was one I thought about, though it is still out of my price range and bigger than I'd want. Your thoughts about the three wheeler were pretty good to me.

 

[Billy T]

If that set of petals drives a small alternator, even when stopped at a traffic light, to help keep a small battery charged and rear wheel has an electric motor in it, that would be interesting. I.e you steadily peddle out ~0.5Hp and part of the time go about five times faster than you can run, without getting wet when it rains. Simple electronics should let the human produced energy go only and directly to the small electric motor when it is adequate for the speed. Hill climbing etc. use battery energy too. I.e most of the time you are using a heavier than normal reclining bike to move.

Do you peddle the yellow "go one" shown in post 2896? Humans are ICs, but seldom considered that way. I.e. how practical is an enclosed Human IC / battery hybrid?

To avoid sliding connections to the "in rear wheel" motor, perhaps in rear wheel, near the rim, there could be a couple dozen or so small permanent magnets and mounted on body near them an electo-magnet coil ( U-shaped, low-hysterious-loss, material) reaching over the rear wheel with well timed sequence of single cycle reversing AC current. I.e. attracts the next approaching PM then goes thru cycle´s zero-current half-cycle point when PM is directly next to it and second half cycle of the current pushes the PM away. The wheel itself would be the "flywheel" of this intermittent pulse motor - perhaps only 6 PMs, one every 30 degree around the wheel, would be enough and be cheaper. I bet a well designed pulse motor system could put 2/3 of the electric energy into the wheel without too much cost or weight.

Timing of current is easy - the not yet energized coil detects the PM approach and switches to the powered mode for one varibale frequency cycle. System knows the changing RPM of the wheel to set that frequency.