top | item 26274667

Tesla is shifting from nickel to iron cathode on standard range car's batteries

102 points| giuliomagnifico | 5 years ago |twitter.com

141 comments

order
[+] antattack|5 years ago|reply
Tesla is shifting nothing. Tesla is consuming all batteries that are available and, after starting operations in China they gained access to CATL who heavily invested in iron phosphate.

Thanks to high efficacy of Tesla drive train, base models can have decent range, around 250miles EPA, with iron phosphate battery packs.

However, iron phosphate battery volumetric density, at this time, does not allow for cars with what I would consider minimum for a single car family, in locations with real winters: 330miles EPA.

[+] audunw|5 years ago|reply
> does not allow for cars with what I would consider minimum for a single car family, in locations with real winters: 330miles EPA.

* in the USA

Our EV (our only car) has 100-150km real-world range (60-90miles). We have real winters. We can get everywhere we want to for daily driving. My grandparents has a cabin 2 hours away that we visit regularly in winter. We can get there one one fast-charge that takes less time than we use to buy groceries for the trip (fast-charger we use is next to a super-market).

I've borrowed my moms ICE car and a friends Tesla Model S for a road-trip across the country a couple of times though.

But Northern Europe does not have the same problem with suburban sprawl and lack of public transportation, people don't usually drive as far regularly, speed limits are lower (higher efficiency) and now there's fast-chargers everywhere.

[+] arcticbull|5 years ago|reply
To be fair, Lithium Iron Phosphate batteries (LiFePO4) are really good technology. Incredibly safe - they don't catch fire in the same way that standard Lithium Ion batteries do - they're better for the environment, have crazy discharge rates, etc. The only thing they're worse at is energy density.

They don't perform badly in winters, I characterized the cold-weather relative performance of LiFePO4 vs LiIon batteries for an aerospace engineering project I did in college.

Frankly I thought those characteristics would outweigh density in automotive applications, but I was mistaken.

[+] mchusma|5 years ago|reply
Difference of opinion, I think 200 miles is plenty of range even for most 1 car families.

That is basically 1 stop from LA to vegas, and 1-2 stops from LA to San Francisco.

I'd like to see focus on lowering the base cost of Teslas, and the lower the range target the easier to get there.

[+] LinuxBender|5 years ago|reply
For what it's worth, this is slowly changing. BattleBorn has certified their LifePo4 batteries to lower temperatures. Been a while since I watched this. [1] Just slower charge rates, but no longer unsafe due to charge controller changes. Previous versions would shut off the charge below 0C. So charging slowly over night may still be useful, but speed charging in cold weather would not.

[1] - https://www.youtube.com/watch?v=ywn-vBjKblI

[+] elif|5 years ago|reply
Minimum single families drive 200 miles per day? Is 'minimum single family' a family of 12 average commuters?
[+] Robotbeat|5 years ago|reply
I’m a big fan of the LiFePO4 chemistry. Super Cheap per kWh, abundant raw materials, extremely long cycle life (even without state of the art manufacturing), and usually a lot more stable and much less likely to start on fire. If you want to DIY a lithium battery pack, LiFePO4 is the least suicidal way to do it.

I see LiFePO4 as enabling Africa to electrify quickly and cheaply. It’s feasible to hook up solar panels to an inverter/charger, a cheap and/or DIYed LiFePO4 battery pack, and combine it with a backup generator to have affordable (less than 15¢/kWh... potentially a LOT less) and (just as important) consistent power without needing access to the grid and that’s like 95% carbonfree.

[+] nabilhat|5 years ago|reply
That's great news! Lithium iron is a much safer chemistry, can handle high discharge rates very well, and has a much greater cycle life. Hopefully, the higher demand will bring the same benefits as with lithium cobalt batteries, improving energy density and bringing prices down.
[+] Animats|5 years ago|reply
Yes. Lithium iron phosphate batteries can pass the "nail test"[1] and ordinary water sprinklers will extinguish fires.[2] Unlike ordinary lithium ion batteries.[3]

I'll bet Tesla omits the titanium skid plate under the battery for those.

Lithium iron phosphate also makes sense for fixed applications. BYD says they've been able to get the energy density per liter up near regular lithium-ion by improved packaging, but lithium iron phosphate is still about 2x heavier.

[1] https://youtu.be/rb_J2QQ0k-4

[2] https://youtu.be/NeaK9V69Xks

[3] https://youtu.be/f30fBFitkSM

[+] myself248|5 years ago|reply
Seriously! I'd be more likely to buy a LiFePO4 car because I know the pack will last basically forever. I don't need incredible range, especially since the supercharger network exists, so that's a pretty sweet deal.

Be nice if it was an option you could order, but whatever.

Be even nicer if some non-Tesla cars would offer it.

[+] guardiangod|5 years ago|reply
I was reading a Chinese EV review comparing BYD's Han to Tesla M3.

https://tieba.baidu.com/p/7138577846

The Han uses iron cathode whereas the Chinese-made M3 uses the nickel cathode.

The Han is ~6000 USD cheaper, but gets slightly higher range than the M3 (Han has longer city driving range, but worse at high way). This is especially impressive when the Han is ~400KG heavier than the M3.

Both cars have comparable charging speed (31%-100% for 1hr 15min).

The reviewer concluded that the Han is a worthy competitor, but Tesla still has an edge at tuning and design. With Tesla switching to iron cathode, I think Tesla can eek out comparable battery performance while maintaining their edge in other areas.

[+] stetrain|5 years ago|reply
They are already using LFP chemistry on Standard Range Model 3 sold in China and Europe. (Batteries produced by CATL I believe)

They also called this out during their last battery tech presentation:

https://cdn.motor1.com/images/mgl/JvxPA/s3/2020-tesla-shareh...

[+] rkangel|5 years ago|reply
I find it interesting that a commercial truck is 'mass sensitive'. Presumably it's because they need a larger battery capacity due to the work needed to haul the load?
[+] post_break|5 years ago|reply
If I understand correctly then it will be lithium iron phosphate? If so that seems like the best chemistry in my limited understand. I've got a huge Lifep04 battery I use to run equipment and the cycle, power density, failure mode, etc are all amazing.
[+] turtlebits|5 years ago|reply
The only problem for vehicles is that LiFePO batteries are heavy. (IIRC ~60% the energy density of Lithium ion)
[+] guerby|5 years ago|reply
My 16 272 Ah LFP cells arrived today (February 26) in France from China (shipped January 11 - 47 days ago).

13.9 kWh for $1248 + $416 shipping and tax, so just shy of $120/kWh delivered ($90/kWh before shipping).

Will be used with an hybrid inverter and solar panels to reduce my electricity bill, UPS my home, and charge my Tesla Model 3 SR+ (2019, USA built so not LFP).

[+] pedrocr|5 years ago|reply
The 3 to 5x difference between those cells and commercial offerings make me hopeful we'll see the market for home batteries take off relatively soon. LFP are ideal for the application and are already cheap. With the cost of rooftop solar continuing to dive, getting a house to be much more energy independent, or even fully off-grid will become almost easy in the next 5 years.
[+] drran|5 years ago|reply
Did you validate capacity? $90/kWh looks great.
[+] colordrops|5 years ago|reply
Where did you order them?
[+] msandford|5 years ago|reply
The tweet talks about swapping iron for nickel, not iron for lithium.
[+] Robotbeat|5 years ago|reply
Yup. In spite of the “lithium is the new oil” meme, lithium is actually super abundant and is often extracted from brines the same way as sea salt is. Lithium isn’t where to focus replacement efforts on.
[+] AtlasBarfed|5 years ago|reply
LFP on standard range is not news, they stated it on battery day I think. Especially since allegedly CATL is making good gains to LFP density.

LFP is cheaper, has insane cycle endurance, is safer, and has great temperature tolerance.

LFP reaching the 200 mile range for a car is a watershed engineering moment for humanity. NMC and others can be dedicated to other tasks.

[+] ArkanExplorer|5 years ago|reply
A smaller, lighter, and slightly cheaper car (which presumably would need fewer batteries) would be a great match for Europe. Driving through and parking in these ancient cities is a real pain with a big car.