Definitely something I missed when I was more skeptical about BEV's and Tesla a few years ago.
It's not about some new breakthrough to make batteries as cheap or energy dense as gas, it's a steady YoY improvement and steady decline in prices.
Lithium batteries where developed in the 70's didn't get released until the 90's and has steadily improved since then with a big cost decline in the last few years.
They are currently up around 300 wh/kg with a theoretical peak of around 2600 wh/kg with sulfur cathodes there is still plenty of headroom for further improvement. At around 2000 wh/kg it roughly equivalent to a diesel drivetrain power density if my math is right.
Cross licensing definitely had a part in it. Some of that was necessity, either practical or contractual. In the 70s, before Projection Masking as a fabrication technique came into play, more complex designs could have yields as bad as 10%.
As a result, 'Second Sourcing' was more frequent, and while Intel and AMD had some Cross Licensing before x86, the main reason the agreement expanded to include x86 was because IBM was still requiring Second Sources in the 80s.
I know at one point, Chevron had it's tentacles on some NIMH patents via their control of Ovonics. Not sure if there are/were any similar situations for Lithium Ion technology.
Also the price fixing done by Lithium companies between 2000-2011. That likely hampered adoption and perhaps improvements.
Years ago I went to a presentation by Tesla in the Bay Area because they were going to let people sit in one of the early prototype Roadsters.
They basically explained that they were betting the company on a "Moore's Law" of batteries. The presentation included a graph of battery capacity doubling every 7 years.
I think that moore's law was a huge contributor to the success of silicon valley.
It let people predict the future 2 or 4 or 10 years out, from the conservative people in charge of finances to the wildcats who are creating new technology that will need something cheap or fast or just viable to match up with when they ship.
2000 wh/kg (crazy units, but I guess this is conventional in some fields?) is 7.2MJ/kg. Diesel fuel and gasoline are something like 40MJ/kg. So same ballpark.
Also, electric motors can easily reach 80%-90% efficiency, while ICE engines in cars typically get 20%-35%. Even in principle ICE engines are thermodynamicly required to be inefficient as combustion itself produces heat, and there is a limit to how much useful work you can extract from a thermal gradient.
You still need to account for the discharge efficiency of the battery (which I cannot find numbers for).
For overall energy usage, electric still still has whatever inefficiencies exist in the generator (and charging inefficiency), but those don't effect power density
The inefficiency inclusion from the generator for electric is somewhat unrelated to an ICE. No ones including the inefficiency of extracting and refining the oil, the huge amounts of time/energy required within the earths crust to create the oil, nor the energy conversion from the sun into organic matter in the first place. It seems a lot of the details on the fossil fuel side get left out.
Discharge efficiency varies from battery to battery. Generally speaking, it's a 90+% efficient process (as is charging). However, there are certainly exceptions which are more or less efficient.
Transmission costs probably eat a bigger portion of EV total efficiency. Those depend on how far you are from your power source and what voltage your power is transmitted at.
That said, a thing EVs do that ICEs can't is accept power from any source. That means that only a fraction of the fuel is actually generated from a fossil fuel.
One other thing to consider is that as power density goes up for batteries, the amount of required batteries go down, ultimately reducing vehicle weight and improving range.
Assuming batteries were ever 10x their current power density, you'd probably not see cars with 10x range, rather, you'd see something like 400mile range cars with the same total power capacity of yesteryear cars. Pretty much all because you've cut the pack weight down by 1/10th (probably less because you need a lot less infrastructure around maintaining temperature for 1/10th the number of batteries).
I wouldn't say you would really count battery discharge efficiency, usually a batteries energy density will be how much useful energy you get out on discharge so it already accounts for charge/discharge efficiency.
Same with electrical generation with generators or whatever. One of the best things about BEV even if run off fossil fuels is that power plants don't care to much about space or weight, they can do multiple levels of heat recovery and whatever emissions controls and get higher thermal efficiency with lower emissions and all that complicated gear is not being carried around in your car nor maintained by you. On top of that now you are decoupled from energy source so changing fuel oil to natural gas or mixing solar, wind or nuclear doesn't change your vehicle.
Most of the energy of combustion is wasted through heat loss. One way to increase efficiency would be a secondary system that harnesses the heat output.
Batteries are usually wh/kg since wh is what you use for battery capacity.
You have to watch it with fuel energy density since it normally doesn't take into account the efficiencies of converting it to useful work and the equipment weight needed, its just the heat energy released when burned. Electrons probably have a really high wh/kg.
A battery has power leads coming out of it to give you electricity and modern electric motors are above 90% efficiency at converting to mechanical energy.
Diesel needs fuel tanks and a heavy engine and more complicated and heavy transmission as well. The engine itself is probably under 40% efficient at converting those MJ to horsepower.
Same goes for fuel cells they are similar in efficiency to ICE and have weight and say with hydrogen storage you need heavy tanks and protective structure to hold safely. Also with hydrogen it has low volumetric density so even though it has good MJ/kg it has low MJ/L relative to say Diesel. All current fuel cell cars are similar in weight to a BEV and seem to have just a slight range advantage with big power disadvantage. Now look at the efficiency of creating hydrogen at I am very skeptical of it becoming mainstream anytime soon.
When I've tried to work out estimates, currently EV's suffer a 20-25% weight penalty over gas/diesel. Part of the weight penalty is due to cascading effects. A battery plus and electric motor weighs more than a gas tank plus engine/transmission. Which means the structural elements have to be heavier.
I think if batteries energy density increases by 50% the weight penalty goes away.
All true but on the good side the weight distribution of the BEV batteries is much better than the weight distribution of the ICE power train. So it's not all just about the amount of weight.
This is also why I've become a bit more skeptical about Nuclear. Renewables + batteries are pretty mediocre right now but if I'm to bet on something for the next twenty years, it's that.
I think nuclear is still really important and has a lot of room for improvement. It's hard to beat its output stability and energy density while emitting no carbon.
Small modular reactors are probably our best bet here. Centrally manufactured, fail-safe designs, short on-site construction times and time-to-first-power-output. It all depends at this point on if the regulatory environment can be improved soon enough for it to matter.
Nuclear is ok for district heating because there aren't many alternatives. Burning gas 20% of the time as backup is not as big of a problem as many people make it out to be. The atmosphere doesn't care when you pollute, just how much, so intermittency is one of the biggest red herrings of all time.
If we had grids with 80% renewables you can start thinking about grid storage but right now it doesn't matter that much.
This happens with just about all technologies: it takes 5 (or 10, or 20) years for the next jump technology to come to market in quantity, but meanwhile the existing technology gets iteratively improved and made cheaper to manufacture - Battery, Solar, Semiconductors.
Often so much that it makes the jump to the new technology not worth it.
On a related note, the first Perovskite based solar cells are due to hit markets this year (after many years of being thought of as too impractical to leave the lab).
Well, not at the promised rate, because they're not 1000x as efficient (which they would be promised in article upon article over 4 decades and compounded).
The other issue is recyclability. Modern li-ion batteries are basically superglued together in order to maximize energy density. A pack designed with recycling in mind will have to be more easily taken apart and likely significantly heavier.
My understanding is currently they just grind up the old batteries into a kind of slurry that then goes through a uniform series of processes to recover the various components.
Batteries are getting better, but we'll almost certainly never reach the fantasy of replacing petrochemicals with batteries 1:1. Instead, what we can do is change our patterns of energy consumption and then we'll start to feel the gains from battery improvement in a more visceral way.
Different technologies are just different. Improvements to batteries will make them a little better at being dropped in as a gasoline replacement, but exponentially better at use cases designed with the lifecycles and energy densities that batteries can comfortably support.
While a lot of focus has been placed on vehicle batteries, I wonder how things are going with stationary batteries, where weight and space are far less important.
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[ 4.5 ms ] story [ 109 ms ] threadIt's not about some new breakthrough to make batteries as cheap or energy dense as gas, it's a steady YoY improvement and steady decline in prices.
Lithium batteries where developed in the 70's didn't get released until the 90's and has steadily improved since then with a big cost decline in the last few years.
They are currently up around 300 wh/kg with a theoretical peak of around 2600 wh/kg with sulfur cathodes there is still plenty of headroom for further improvement. At around 2000 wh/kg it roughly equivalent to a diesel drivetrain power density if my math is right.
Patents last for 20 years.
As a result, 'Second Sourcing' was more frequent, and while Intel and AMD had some Cross Licensing before x86, the main reason the agreement expanded to include x86 was because IBM was still requiring Second Sources in the 80s.
I know at one point, Chevron had it's tentacles on some NIMH patents via their control of Ovonics. Not sure if there are/were any similar situations for Lithium Ion technology.
Also the price fixing done by Lithium companies between 2000-2011. That likely hampered adoption and perhaps improvements.
They basically explained that they were betting the company on a "Moore's Law" of batteries. The presentation included a graph of battery capacity doubling every 7 years.
It let people predict the future 2 or 4 or 10 years out, from the conservative people in charge of finances to the wildcats who are creating new technology that will need something cheap or fast or just viable to match up with when they ship.
You still need to account for the discharge efficiency of the battery (which I cannot find numbers for).
For overall energy usage, electric still still has whatever inefficiencies exist in the generator (and charging inefficiency), but those don't effect power density
Transmission costs probably eat a bigger portion of EV total efficiency. Those depend on how far you are from your power source and what voltage your power is transmitted at.
That said, a thing EVs do that ICEs can't is accept power from any source. That means that only a fraction of the fuel is actually generated from a fossil fuel.
One other thing to consider is that as power density goes up for batteries, the amount of required batteries go down, ultimately reducing vehicle weight and improving range.
Assuming batteries were ever 10x their current power density, you'd probably not see cars with 10x range, rather, you'd see something like 400mile range cars with the same total power capacity of yesteryear cars. Pretty much all because you've cut the pack weight down by 1/10th (probably less because you need a lot less infrastructure around maintaining temperature for 1/10th the number of batteries).
Same with electrical generation with generators or whatever. One of the best things about BEV even if run off fossil fuels is that power plants don't care to much about space or weight, they can do multiple levels of heat recovery and whatever emissions controls and get higher thermal efficiency with lower emissions and all that complicated gear is not being carried around in your car nor maintained by you. On top of that now you are decoupled from energy source so changing fuel oil to natural gas or mixing solar, wind or nuclear doesn't change your vehicle.
You have to watch it with fuel energy density since it normally doesn't take into account the efficiencies of converting it to useful work and the equipment weight needed, its just the heat energy released when burned. Electrons probably have a really high wh/kg.
A battery has power leads coming out of it to give you electricity and modern electric motors are above 90% efficiency at converting to mechanical energy.
Diesel needs fuel tanks and a heavy engine and more complicated and heavy transmission as well. The engine itself is probably under 40% efficient at converting those MJ to horsepower.
Same goes for fuel cells they are similar in efficiency to ICE and have weight and say with hydrogen storage you need heavy tanks and protective structure to hold safely. Also with hydrogen it has low volumetric density so even though it has good MJ/kg it has low MJ/L relative to say Diesel. All current fuel cell cars are similar in weight to a BEV and seem to have just a slight range advantage with big power disadvantage. Now look at the efficiency of creating hydrogen at I am very skeptical of it becoming mainstream anytime soon.
I think if batteries energy density increases by 50% the weight penalty goes away.
Just have to figure out how to keep it safe.
If we had grids with 80% renewables you can start thinking about grid storage but right now it doesn't matter that much.
Often so much that it makes the jump to the new technology not worth it.
https://m.youtube.com/watch?v=8RbwOhM6PUk
Different technologies are just different. Improvements to batteries will make them a little better at being dropped in as a gasoline replacement, but exponentially better at use cases designed with the lifecycles and energy densities that batteries can comfortably support.