Battery advancements thread

orbital

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General thread for battery advancements

Mid August 2020: Elon Musk is hinting on dramatic increase in battery capacity, saying 400 Wh/kg could be just 2~3 years away.
(hard to bet against a guy who can land a rocket vertically)

"so 400 Wh/kg would represent a significant hike for energy density in a battery compared to the cells now used in several EVs, which sit above 230 Wh/kg"
from: autoweek.com



Imagine a 21700 @ 8750mAh

_______________________________________________________________________________
Currently Tesla produces 4.75 billion 21700 cells per year, and that's going to increase
 
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lumen aeternum

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"Imagine a 21700 @ 8750mAh "
Depends on the shape & size of the battery. It might have a lot of surface area for cooling, so shaped like an asterisk or something. How many Wh per cubic inch, when the battery is in a box?
 

orbital

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Tesla is going w/ 46x80mm cells or 46800 if that makes sense.
they are saying 5 times the energy & 6 times the power per unit of size.

think of 2x 46800 light possibilities,
something like a 2D Maglite on super steroids, really super steroids
 
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electromage

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ID of M*g "D" flashlight is about 34mm and obviously 38mm OD cell will not fit.
Well it was fun to think about it. If anyone can make it work I would think it's you :), maybe a mild "Elephant" style body would do it. The cells are rated for 200A so the potential for fun is high.
 

lumen aeternum

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Is there a standard diameter of tubing that could fit 38mm cells?
Really hi amp batteries could support built-in fans for great cooling.
 

fuyume

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Obviously, for a company like Tesla that uses large numbers of cells in parallel, the larger the cell, the more efficient the use of packaging materials. For consumers, it’s hard to see how a 46 mm diameter cell is going to be useful. It’s simply too large to be put into a device that can be comfortably handheld by most people, and the dangers involved in catastrophic failure of a cell that large are not insignificant. The 21700 results in devices that are about 1” in diameter, and that’s comfortable for even people with small hands.

I would argue that even a D cell is really too big in diameter for a lot of people, so I can see maybe a move to a about a 28 mm cell (about 1.125”, which would end up with about a 1.25” ish grip size), but any larger than that I just don’t see as being practical. Even at that size, it would really only be desirable in heavy-duty devices, not things most people are going to want to tote around. I think the 21700 is going to remain the mainstream standard for a long time to come. It’s a good balance of power to size/weight/safety.
 

Lynx_Arc

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I agree with fuyume about 46800s. I think even if made safe they may be rather costly just to get a single cell and likely going to be pretty much nothing using them for awhile but I think that they may be great for tool batteries and things like lanterns and such..... maybe larger power banks, jump starter packs, inverter ammo, large bluetooth speakers etc.
May make ideal batteries for lawn mowers and large power hungry tools. Most likely these batteries will be unobtainable for awhile due to electric cars eating the supplies of them up. The one thing that could greatly encourage the use of them is a considerably lower cost per watt hour vs 18650 and 21700 cells plus perhaps higher power density.
 
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