4680 batteries, what is the advantage?

[MontyFloyd]

4680 batteries, what is the advantage?

4680 is evolutionary, not revolutionary change from what I read.
There is little chemical change from other types (18650 and 2170) and uses the same "jellyroll" design. The significant change is size (less so the so called "tabless" design, which IMHO is a "full tab").

From a mfg standpoint, 4680 will be far cheaper since there will be fewer of them needed, one can replace five of the 2170
From a capacity stand point it will be more, again because of size.
A car with 4680 will have more range as a result.

All good, but would a completely different battery design be better, like a Li Ion flat battery?
Or is the integration into a large battery pack make cylindrical design better (eg. better cooling)?

What I do think is Tesla made a safe decision in a design that had a very high chance of success, vs something like "solid state battery" that still is no closer to production than 10 years ago.

When will we see 4680 be installed in cars and PowerWall? 1 Jan 2022?

 

[theothertom]

Tesla started using cylindrical batteries to reduce the risk of fire. Almost all other EV manufacturers use the "flat pack" design which are called pouch cells or prismatic. The LFP battery packs that are used in the SR+ (or RWD as it's now called) are prismatic. LFP cells are lower energy density than NCA so prismatic helps mitigate that disadvantage somewhat. Also, LFP chemistry is less fire prone than NCA so cylindrical cells aren't needed. But, there are disadvantages to LFP. As with most things, there are trade offs.

 

[nativewolf]

The LFP patents expire, for the USA, 2022. This may have been a holdup in chemistry and manufacturing development but I have hard time believing it. I feel that competitor OEM have just been lazy and chose to outsource the parts of an EV that are not in the normal wheelhouse (battery, software, chips, thermal management, EV drivetrain, etc) . An example- the battery is an afterthought and LG is really the company making the bolt/volt vs GM.

I suppose I'm surprised at the LG and SK and Samsung emphasis on NI chemistry pouch batteries. Usually the Korean companies have been pretty adept at avoiding errors like this. Further ironic that western universities basically handed the Chinese companies the keys to the kingdom re LFP- what idiots in licensing. Anyhow CATL certainly took advantage and has quite good LFP solutions and is building out capacity in the USA and EU. I'm sure that US LFP competitors will arise but will they achieve funding to scale quickly?

As it stands now almost all the battery capacity planned in the USA and EU are pouch based NI LI solutions that have challenges in terms of supply chain management and implementation. Really only Tesla has cell designs at scale which are rugged.

To the OP watch a few of Sandy Munro's videos on the 4680 they explain a bit about the usefulness. It is just a great evolutionary battery. Nothing revolutionary. Manufacturing turned out to be a pickle but I guess they've solved that.

 

[MontyFloyd]

Tesla started using cylindrical batteries to reduce the risk of fire. Almost all other EV manufacturers use the "flat pack" design which are called pouch cells or prismatic. The LFP battery packs that are used in the SR+ (or RWD as it's now called) are prismatic. LFP cells are lower energy density than NCA so prismatic helps mitigate that disadvantage somewhat. Also, LFP chemistry is less fire prone than NCA so cylindrical cells aren't needed. But, there are disadvantages to LFP. As with most things, there are trade offs.

An alphabet soup of acronyms, these correct?
LFP = lithium iron phosphate battery (LiFePO4 battery)
NCA = Lithium Nickel-Cobalt-Aluminum Oxide (NCA)
SR+ = Tesla Model 3 SR+, renamed RWD, is this the "Standard" on Tesla order site?

The LFP patents expire, for the USA, 2022. This may have been a holdup in chemistry and manufacturing development but I have hard time believing it. I feel that competitor OEM have just been lazy and chose to outsource the parts of an EV that are not in the normal wheelhouse (battery, software, chips, thermal management, EV drivetrain, etc) . An example- the battery is an afterthought and LG is really the company making the bolt/volt vs GM.

I suppose I'm surprised at the LG and SK and Samsung emphasis on NI chemistry pouch batteries. Usually the Korean companies have been pretty adept at avoiding errors like this. Further ironic that western universities basically handed the Chinese companies the keys to the kingdom re LFP- what idiots in licensing. Anyhow CATL certainly took advantage and has quite good LFP solutions and is building out capacity in the USA and EU. I'm sure that US LFP competitors will arise but will they achieve funding to scale quickly?

As it stands now almost all the battery capacity planned in the USA and EU are pouch based NI LI solutions that have challenges in terms of supply chain management and implementation. Really only Tesla has cell designs at scale which are rugged.

To the OP watch a few of Sandy Munro's videos on the 4680 they explain a bit about the usefulness. It is just a great evolutionary battery. Nothing revolutionary. Manufacturing turned out to be a pickle but I guess they've solved that.

SK is SK Group is a South Korean conglomerate?
NI is what?

Seen a few Sandy video's, will look for that one.


Any guess when Tesla will start using 4680s? I hear that Berlin will, maybe Austin.

 

[theothertom]

An alphabet soup of acronyms, these correct?
LFP = lithium iron phosphate battery (LiFePO4 battery)
NCA = Lithium Nickel-Cobalt-Aluminum Oxide (NCA)
SR+ = Tesla Model 3 SR+, renamed RWD, is this the "Standard" on Tesla order site?

As I understand it, yes

SK is SK Group is a South Korean conglomerate?
NI is what?

SK (really SKI) is a South Korean conglomerate. They're building a new battery plant in the US to supply VW and Ford
"NI LI solutions" I think is a reference to Ni-Li battery chemistry.

 

[MontyFloyd]

Since Sandy's video was mentioned, I will post videos about 4860.

From EEVblog #1340

Wealth UP

Sandy Munro

Tesla News and Reviews | InsideEVs

Get the latest on new Tesla models including spy shots, first drives, in-depth reviews, concept car photos, new features and more.

insideevs.com

Tesla’s 4680 battery cell is 'brilliant' according to industry experts

Tesla CEO Elon Musk showed the road to 56% cheaper batteries in the near future. How? Breakthrough innovations in cell chemistry and materials, simplifying and speeding up cell manufacturing processes, a structural battery, and the company's new 4680 form factor. So what do the experts think of...

evannex.com

(there is more, but I think I posted all the significant videos.

 

[nativewolf]

Great summary

 

[MontyFloyd]

This irks me a little as is a clear misnomer, have to rant.
It is called "tabless", yet it clearly has tabs, a lot of them, folded on each other.
What is better name, "edge connector"? "Full tab"? "Multi-tab"?

 

[MontyFloyd]

Happened on this, not need see earlier.

Tesla’s 4680 battery cell pilot production line hits 70-80% yield: report

Tesla has a number of programs that have the potential to change markets, and one of these is arguably the 4680 cells. Created using a dry electrode process and optimized for price and efficiency, the 4680 batteries could very well be the key to Tesla’s possible invasion of the mainstream auto...

www.teslarati.com

production yield of the 4680 cells has reportedly risen to about 70-80%,

Wow, 70~80% is incredibly low. I am sure better now, but need better than 99% to be viable

Once the literal kinks are worked out, game changer.

 

[theothertom]

but need better than 99% to be viable

Manufacturing yields are rarely 99% or better. IMO low 90's would be viable.

 

[Hurricane4911]

This irks me a little as is a clear misnomer, have to rant.
It is called "tabless", yet it clearly has tabs, a lot of them, folded on each other.
What is better name, "edge connector"? "Full tab"? "Multi-tab"?

Absolutely correct, they do have tabs...
In 2170s, current travels the entire length of the jelly roll from anode to cathode. 4680s have edge tabs whereby the current travels the shorter width of the roll.

Yes they have tabs, lots of them!

 

[MontyFloyd]

Manufacturing yields are rarely 99% or better. IMO low 90's would be viable.

What is yield for 1865 and 2170?

 

[Gauss Guzzler]

It is called "tabless", yet it clearly has tabs, a lot of them, folded on each other.
What is better name, "edge connector"? "Full tab"? "Multi-tab"?

I'd say "integral" tabs, if you insist on using the word "tab".

What's important here is that the "tabs" are no longer a separate piece of metal spot welded into the layers. Traditional welded tabs create dangerous lumps in the roll and need to be very thin and narrow in order to fold/roll reasonably well so it's typically the tabs that define the maximum charge/discharge current limit of the cell. This is why no one makes large diameter cells and why the smaller 18mm diameter cells of the Model S can produce so much more power than the 21mm cells of the Model 3 - because there are more of them (7,920 vs 4,416) and therefore more tabs to share the current. The "integral tabs" of the 4680 completely remove this bottleneck and provide excellent thermal conductivity as a side benefit. These two benefits make it possible to produce larger diameter cells which are cheaper due to fewer parts and connections, and lighter due to less case material and simpler thermal management.

 

[Brando]

Absolutely correct, they do have tabs...
In 2170s, current travels the entire length of the jelly roll from anode to cathode. 4680s have edge tabs whereby the current travels the shorter width of the roll.

Yes they have tabs, lots of them! @MontyFloyd @GtiMart

edges [cut to allow folding] vs tabs [must be added by soldering] ==> "tabless" seems a fine description

 

[nativewolf]

I'd say "integral" tabs, if you insist on using the word "tab".

What's important here is that the "tabs" are no longer a separate piece of metal spot welded into the layers. Traditional welded tabs create dangerous lumps in the roll and need to be very thin and narrow in order to fold/roll reasonably well so it's typically the tabs that define the maximum charge/discharge current limit of the cell. This is why no one makes large diameter cells and why the smaller 18mm diameter cells of the Model S can produce so much more power than the 21mm cells of the Model 3 - because there are more of them (7,920 vs 4,416) and therefore more tabs to share the current. The "integral tabs" of the 4680 completely remove this bottleneck and provide excellent thermal conductivity as a side benefit. These two benefits make it possible to produce larger diameter cells which are cheaper due to fewer parts and connections, and lighter due to less case material and simpler thermal management.

That's quite helpful Gauss Guzzler ..which is also a clever name.

 

[Schmidlack]

I'd be hesitant to purchase one of the first few thousand cars equipped with 4680 cells. Seems pretty challenging to perfect the manufacturing process. I hope the ramp-up is gradual.

Meanwhile, I still don't see what the benefit(s) to the customer will be.

 

[MontyFloyd]

Meanwhile, I still don't see what the benefit(s) to the customer will be.

Cost.
Cheaper to produce 4680 and cheaper to assemble a battery pack in a load bearing design, at a guess easily save $5000 off mfg cost.

Also a guess, but I think producing this cell since January 2021.

 

[GlmnAlyAirCar]

Cost.
Cheaper to produce 4680 and cheaper to assemble a battery pack in a load bearing design, at a guess easily save $5000 off mfg cost.

Also a guess, but I think producing this cell since January 2021.

But that is a benefit to the company, not to the end user.

 

[theothertom]

But that is a benefit to the company, not to the end user.

My guess is, with demand like it is today, Tesla will capture any cost savings and report them as profit.
As to the benefit to the customer, Tesla announced at battery day that the 4680 would have ~54% more energy density, which theoretically put the MYLR range at around 475 miles.
My guess is they won't put as many batteries in the car (cost savings again) but maybe bump the range 10% or so.

 

[ItsNotAboutTheMoney]

But that is a benefit to the company, not to the end user.

Until the point they need to lower the price for competitive reasons.