No longer a bottleneck because demand is down?
this post was submitted on 27 Jan 2024
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[Dormant] Electric Vehicles
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This is a tesla ad.
To be fair, I saw it in an obscure Tesla community. But the new batteries are considered to be better than 18650s or 21700s, so the fact that Tesla has perfected their manufacturing is good for the industry as a whole.
Considered by who? They charge slower, their energy density is slightly worse, and they're more expensive than supplier sources cells. Tesla botched all of the desired improvements because they once again assumed they could harass employees into making breakthroughs that have been worked on in the industry for decades.
I am by no means an Elon fanboy and so I'm really not going to go on a ledge to argue for his companies, so I asked Bard to. The initial reply was heavily pro 4680, so I asked more negatively:
It's not entirely accurate to say that 2170 batteries are simply "better" than 4680 batteries for cars. Both have their own advantages and disadvantages, and the "better" choice depends on the specific needs and priorities of the manufacturer and the vehicle. Here's a breakdown of the pros and cons:
2170 Batteries:
Pros:
- Mature technology: With longer years of research and development, 2170 batteries offer proven stability, reliability, and performance.
- Lower production cost: Established manufacturing processes and supply chains for 2170 cells make them less expensive to produce than the newer 4680 batteries.
- Wider compatibility: Smaller size makes them compatible with a wider range of existing battery pack designs and vehicle platforms.
- Faster charging: In some cases, 2170 batteries can achieve faster charging rates than 4680 cells, especially when considering limitations in current charging infrastructure.
Cons:
- Lower energy density: Compared to 4680 cells, 2170 batteries store less energy per unit volume, leading to shorter range and requiring more cells to achieve the same pack capacity.
- More complex manufacturing: Smaller size requires more cells and connections, resulting in a more complex battery pack design and assembly process.
- Limited scalability: Due to their lower energy density, it can be challenging to significantly increase range using 2170 batteries without increasing pack size or weight.
4680 Batteries:
Pros:
- Higher energy density: As mentioned, 4680 cells store more energy per unit volume, potentially leading to longer range and requiring fewer cells for the same pack capacity.
- Simpler manufacturing: Larger size and tabless design simplify battery pack assembly and potentially reduce production costs in the long run.
- Potential for faster charging: Tesla claims improved charging rates for 4680 cells in the future, although current production versions might not yet demonstrate this advantage.
- Scalability: Higher energy density allows for significant range increases without substantial increases in pack size or weight.
Cons:
- Early stage technology: Compared to 2170, 4680 batteries are still relatively new and lack the same level of data on long-term performance and reliability.
- Higher production cost: Currently, 4680 batteries are more expensive to produce due to the new manufacturing processes and limited supply chains.
- Compatibility limitations: Large size might limit their compatibility with existing vehicle platforms and require adaptations in battery pack design.
Conclusion:
The choice between 2170 and 4680 batteries depends on various factors. 2170 offer proven technology, affordability, and faster charging in some cases, but face limitations in range and scalability. 4680 batteries boast higher energy density, simpler manufacturing, and potential for future improvements, but currently lack data on long-term performance and face higher production costs and compatibility challenges.
Ultimately, the "better" option depends on the manufacturer's priorities and the specific needs of the vehicle. Different companies might make different choices based on their goals and resources.
so I asked Bard to
Let me stop you here and say you're going to have a bad time if you attempt to have this explained to you by a text generator.
The first problem is you asked it about the form factor rather than the cells, manufacturing process, and chemistry themselves. The shape makes perhaps the least difference of all. Well, except that Panasonic (the company that actually invented Tesla's "revolutionary" battery tab mechanism) already documented a ton of issues with assembling cells reliably when you've got a bunch of tabs. What you want in that case is actually a pouch cell or a prismatic.
Bard also missed a pretty major one under "Lower production cost". Massive volume makes 21700 cells cheaper too, since all of your costs are divided by a huge number. This is also why 18650s are beating the 21700s. Also, fun fact, Tesla's top performing pack for charge and discharge rates is built in 18650 NMC cells.
Wider compatibility
That's a meaningless argument produced by a text generator.
Faster charging
Not some cases. All cases. All of Tesla's products based on 21700 cells from all of their suppliers charge faster than any of the packs based on Tesla's in-house cells. Charging "infrastructure" has absolutely nothing to do with this, it's a nonsense hallucination by a text generator. This is one of the major reasons to not use one.
Lower energy density
This is just an outright lie, which you could determine by doing the math. Tesla's early Model 3 cells were 17.3 Wh each, while their in-house 46800 are 86 Wh. The Model 3 cells have improved over time, but let's stick with the earliest of both products. So this means their 21700 cells were 247 Wh/kg while the 46800s are 244 Wh/kg. Taking the volume of each cell into account, the old Model 3 cells are 713.55 Wh/L and the 46800 cells are 651.5 Wh/L. So the simple math clearly shows it's lower density in both dimensions.
Bard slurped up text from marketing efforts and mangled it with some other words and gave it to you. This is a warning not to use these things to learn new topics, they're less reliable than Wikipedia.
More complex manufacturing
This is another nonsense argument. First and foremost, Tesla uses stamped collectors on the Y and 3 packs based on 21700 cells so there's really no more complexity in manufacturing. On the S and X packs, they use bonding wires. Bonding wires robots do this work insanely quickly, so it's a foolish argument there as well. Bard has again slurped up nonsense from a fan blog and repeated it, because there's no intelligence in what Bard does. Trusting these things blindly is a problem.
As an example of what bonding wire robots do, BTW, they are used in the production of every single processor and microprocessor on the planet. Products numbering in the tens if not hundreds of billions per year, with precision requirements wall beyond anything Tesla needs for their old packs from 2012, let alone the newer stamped collectors from 2018.
Limited scalability
I already demonstrated that the energy density bit was made up nonsense. But this part is also complete horse shit. Cell chemistry tends to improve approximately 5% per year averaged over a 5 year window. Tesla didn't increase the pack dimensions when going to the 82 kWh Model 3 pack, they simply changed cell chemistry. If I used the cells from that pack in the calculations above, it would make this argument outlandishly pointless.
4680 Simpler manufacturing
The cell isn't "tabless" bit instead has a shitload of tabs. Like I said already, Panasonic invented this tech and they abandoned it because it's a frequent source of cell failure. Their patents on this are from over a decade ago, they documented all of their issues pretty well, and Tesla's own internal documents when leaked showed they have massive yield problems in their Texas battery factory.
Potential for faster charging
Potential. And instead what we see in real products on sale is the opposite. so that potential didn't materialize.
Thanks for this. It was insightful.
Cool, a giant ai generated block of nonsense.
Are you ok? What the fuck is with the negativity in this thread? What did your shit attitude add to conversation?
Giant AI generated walls of text posted by people that aren't qualified to proof them for factual content may as well be spam. It's an increasingly common thing I see here and it provides no value.
I'm happy to learn. I was under the impression that the new batteries were superior and everything I read seems to support that, but you all say otherwise and thus I would like to humbly ask you to qualify why
When the only things you read are Tesla marketing, it's unlikely you'll get the truth.
I already qualified some reasons why but let me be more explicit. The cells charge slower, are lower energy, cost more, and are heavier. They delivered on none of the hype, they were years late, their production numbers are hilariously low, and the manufacturing yields are far lower than competitors.
Thank you, I just read.