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CATL has announced a new “condensed” battery with 500 Wh/kg

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Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#241

Post by zamnos »

leoedin wrote: post #189
msravi wrote: post #133

I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy. By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted ar…

The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will…

> the absolute best theoretical efficiency of this might be 70%

I fell down a rabbit hole and found this link, which gives 46% for the theoretical limit for the efficiency of the internal combustion engine.

https://physics.stackexchange.com/questions/98966/maximum-th...

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#242

Post by qikInNdOutReply »

msravi wrote: post #133

I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy. By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted ar…

So, how about we apologize in public to the engineers who said no to radar, cause boy oh boy would that one have eaten battery, which would need additional batteries, which would have torrn into the car rocket equation ?

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#243

Post by sveme »

cultureswitch wrote: post #204
theK wrote: post #110

Earlier quoted context omitted.

I’m afraid these bans get systematically sabotaged by well funded ice lobby groups. Just look at what happened to the EU’s ice ban for personal vehicles. Spoiler: while new gasoline burning cars are technically banned after 2035 it will be completely legal to sell new gasoline burning cars by labelling them e-fuel only…

The timelines for ICE bans within a decade are ridiculous from a technology and market standpoint and terrible for the environment. The best car technology is the one you don't use much. And we already have decades of cars in good enough condition to be driven weekly rather than daily. EVs will barely scratch the surface of environmental issues with transportation. And they will create a new range of supply problems…

I think you should read up on what ICE bans in countries where they are implemented actually means.

Hint: You can continue to use the ICE vehicle you bought in 2034 in the EU until infinity.

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#244

Post by imiric »

oblio wrote: post #162
imiric wrote: post #42

Earlier quoted context omitted.

Electric planes could recharge using solar or wind. As efficiency increases with these technologies, it would mean planes wouldn't require carrying the same watt-for-watt energy as fuel.

> Electric planes could recharge using solar or wind. As efficiency increases with these technologies, it would mean planes wouldn't require carrying the same watt-for-watt energy as fuel. Those are pipe dreams :-))) Solar recharging for electric cars is not realistic, let alone for electric planes. Wind charger... maybe there's something there, but the fact that nobody has tried it probably means it's not good enoug…

Planes have a much larger surface area to carry solar panels, and they fly above clouds, so have clearer access to sunlight than cars do.

Wind charging is more of a pipe dream, but there's no reason a plane couldn't glide for a period of time to get some energy back, similar to regenerative breaking.

There have been experiments in both areas, and while it's certainly unfeasible today for any large aircraft, the technology and efficiency will only improve. It would be wrong to discard these as an impossibility.

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#245

Post by ly3xqhl8g9 »

londons_explore wrote: post #235
ly3xqhl8g9 wrote: post #159

Earlier quoted context omitted.

Iron-air batteries (1,200 Wh/kg), and in general metal-air [1], might bring a surprise after 2024: December 2022, "Form Energy will site first American iron-air battery manufacturing plant in Weirton, West Virginia" [2]. [1] 2017, Yanguang Li, Jun Lu, Metal–Air Batteries: Will They Be the Future Electrochemical Energy Storage Device of Choice? https://pubs.acs.org/doi/10.1021/acsenergylett.7b00119 Betteridge's law of…

The various "-air" batteries tend to have major downsides... They tend to get heavier as they discharge. They usually aren't rechargeable (or if they are, only a few times or with much lower energy densities). They tend to self-discharge within a few weeks of non-use.

Yes, there are downsides, as always in engineering, it's a matter of managing the compromises for the current implementation and researching better solutions for the next iteration.

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#246

Post by fwlr »

someweirdperson wrote: post #137
fwlr wrote: post #73

Earlier quoted context omitted.

I don’t think Musk has given a writeup of his reasons for thinking 400wh/kg is the magic number, but a lot of research has been done that says similar numbers. This paper https://www.sciencedirect.com/science/article/pii/S2666691X2... is a good review; it cites researchers saying 800wh/kg for an electric Airbus A320, NASA saying 400Wh/kg for general aviation and 750Wh/kg for regional aviation, and other researchers s…

> Jet fuel gets roughly 28% final efficiency while electric gets roughly 90% 90% likely doesn't include the efficieny of the prop?

I believe it does, that paper is comparing like-for-like jet turbines vs electric engines.

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#247

Post by john61 »

msravi wrote: post #133

I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy. By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted ar…

What about charging efficiency?

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#249

Post by microjim »

nvy wrote: post #13
microjim wrote: post #5

Cool! What didn’t occur to me until I learnt it was that you get a multiplicative benefit with energy density when weight is a major factor (air transport, especially) because you need to spend less energy accelerating mass used by the battery itself.

For a battery of arbitrary weight you need to spend the same amount of energy accelerating its mass, irrespective of how much energy that battery contains.

Yes that’s correct. Probably a better way of articulating what I meant to say is that unlike adding more battery mass which gives you diminishing returns as that additional weight must be carried too, improvements in energy density give you gains closer to 1:1. Though in retrospect this isn’t a very interesting or insightful statement, hah.

Re: CATL has announced a new “condensed” battery with 500 Wh/kg

#250

Post by walrus01 »

leoedin wrote: post #189
msravi wrote: post #133

I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy. By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted ar…

The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will…

> A modern series hybrid like a Toyota Prius is effectively an electric vehicle and a gas generator (which means it has the same efficiency gains due to regenerative braking). That gets 52 mpg, which is about 493 Wh/km.

Wait, does a new prius or something like a hyundai ioniq (also 52-53 mpg) not have the internal combustion engine mechanically coupled to the transmission and drive wheels anymore?

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