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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

#31

Post by Toutouxc »

thriftwy wrote: post #25
pcurve wrote: post #20

Earlier quoted context omitted.

Yep. Also... kerosene gets spent. Pilots can also dump fuel in emergency when it's too heavy to land. Battery powered planes can't dump electricity, so I'd imagine some trade offs that have to be made.

Electric engines may be much more reliable than kerosene engines.

This is more about day to day operations than emergencies. For an electric plane, your MTOW (max takeoff weight) is equal to your MLW (max landing weight). An ICE plane can take off with "bonus" fuel that it can't land with for structural reasons, while an electric plane can't.

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

#32

Post by daliusd »

buro9 wrote: post #17
nvy wrote: post #13

Earlier quoted context omitted.

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.

The article mentions aircraft multiple times. Once a range is achieved through available energy, reducing weight is a goal. The energy is more useful the less weight you need to move as then you can shave off a bit more weight as less energy was needed. Your car may not need this as much, an aircraft does.

Bicycles would benefit as well. I would love if my electric bicycle were slightly lighter.

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

#33

Post by gibolt »

buro9 wrote: post #17
nvy wrote: post #13

Earlier quoted context omitted.

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.

The article mentions aircraft multiple times. Once a range is achieved through available energy, reducing weight is a goal. The energy is more useful the less weight you need to move as then you can shave off a bit more weight as less energy was needed. Your car may not need this as much, an aircraft does.

500-600 Wh/kg is the target for replacing average flight durations.

Fuel is one of the highest costs for an airline, so eliminating the majority of that will make the demand for any viable options go bananas, even with a much higher upfront cost.

Being seen as 'green' is a big bonus for the airline.

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

#34

Post by jansan »

pcurve wrote: post #20
idontwantthis wrote: post #4

Why does 500wh/kg make electric aircraft possible? 6x less than kerosene. Is that the break even on cost if you can source very cheap electricity? Seems like it would still annihilate the payload/range.

Yep. Also... kerosene gets spent. Pilots can also dump fuel in emergency when it's too heavy to land. Battery powered planes can't dump electricity, so I'd imagine some trade offs that have to be made.

That is a very good and often overlooked point. So in average on a flight one has to calculate maybe with 60% weight of kerosene, while the battery keeps 100% of its weight during the entire flight.

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

#35

Post by dzhiurgis »

oriel wrote: post #27
gibolt wrote: post #24

Earlier quoted context omitted.

Current mass produced batteries, which tend to hover around 260-300 Wh/kg. Higher density (but still under 500) are available, but in far smaller quantities for a very high cost. The exciting part of this announcement is that if anyone can scale manufacturing, it is them.

Really it is encouraging for advancement areas like this. Reminds me of the "revolutionary battery checklist": https://news.ycombinator.com/item?id=28025930 edit: removed the paste of the checklist because of spam.

“No week goes by without a revolutionary battery technology”

- Engadget, circa 2010

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

#36

Post by pcurve »

thriftwy wrote: post #25
pcurve wrote: post #20

Earlier quoted context omitted.

Yep. Also... kerosene gets spent. Pilots can also dump fuel in emergency when it's too heavy to land. Battery powered planes can't dump electricity, so I'd imagine some trade offs that have to be made.

Electric engines may be much more reliable than kerosene engines.

I would hope so, considering this is what it looks like inside. https://en.wikipedia.org/wiki/Rolls-Royce_Trent_1000#/media/...

But. Turbine engine is actually very reliable and doesn't need overhaul for 20,000 flight hours.

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

#37

Post by rgmerk »

nvy wrote: post #9
idontwantthis wrote: post #4

Why does 500wh/kg make electric aircraft possible? 6x less than kerosene. Is that the break even on cost if you can source very cheap electricity? Seems like it would still annihilate the payload/range.

Seems like marketing hype to me. An 8-hour transatlantic flight requires something like 600MWhr of energy. That's about 75MW, which is in small nuclear reactor territory.

Not every flight is transatlantic.

These batteries, if they deliver on the advertised specs and aren’t too expensive should make short-range electric aviation possible.

The electric air taxis that Joby and others are working on suddenly have a lot bigger margin to work with, as do electric regional airliners.

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

#38

Post by gibolt »

tormeh wrote: post #22
idontwantthis wrote: post #4

Why does 500wh/kg make electric aircraft possible? 6x less than kerosene. Is that the break even on cost if you can source very cheap electricity? Seems like it would still annihilate the payload/range.

We're talking short flights here.

Not at this density. This is the minimum requirement for medium length large airplanes. Small aircraft are already viable with mass produced batteries.

As they scale production of these, hopefully they can get 20% additional improvements at the cell/pack level, reaching potential to replace the most common flights.

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

#39

Post by krasin »

Someone wrote: post #29
krasin wrote: post #19

Earlier quoted context omitted.

Let's consider Cessna-172S ([4]). Its characteristics: - 130 kW engine, Lycoming_O-360 that weighs 117 kg. For comparison, an electric motor of this range would weigh 11-13 kg (at 10-12 kW/kg, [2]). That saves 100+ kg weight immediately and we can put 50+ kWh batteries instead. - It carries up to 200 liters of kerosene ([3]), which weighs 164 kg. We can place 82 kWh of batteries instead. - The engine consumes around…

The airplane would be a bit heavier at landing, though. I expect that will require a somewhat heavier landing gear. I also think taking out the weight of the tank is unfair if you don’t add weight for the structures for holding the batteries. But yes, for many smaller planes, we’re close to flying electric on shorter flights being economically feasible.

Fair points.

But the point that CATL makes with this announce is that before this capacity boost, electric planes were a complete joke. Now, they are only somewhat funny.

What I am more excited about is that electrically pumped rockets are now a lot more practical. As an example, Electron is such a rocket ([1]). It can now reduce the weight of the battery pack and increase payload.

1. https://en.wikipedia.org/wiki/Rutherford_(rocket_engine)

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