This took a few reads to parse. There are two kinds of batteries: (1) a low-density LFP that has a great lifetime, (2) a simulated manganese using Nickel manganese cobalt that has a poor lifetime but great density. The former cycles frequently for short trips, and the latter recharges it during the long ones.
It leverages the fact that most people make a large number of short trips, and a smaller number of long trips.
Also if it's modular enough, this design could allow replacing one or the other battery if the user does lots of short trips, or lots of long trips.
Also could let the manufacturer do market segmentation, e.g. a high performance model with no LFP, and both parts of the "high-performance" chemistry - and a base model that's 100% LFP.
You need more LFP to carry the weight of the manganese battery though (increasing cost), and all the extra weight can affect driving dynamics. Maybe both the cost and weight increase are minimal but that’s what came to mind. It’s a great idea though.
The unfortunate thing with the whole drag-coefficient game is it ultimately results in fish-shaped cars and zero unique designs.
Between EVs and crossovers we're suffocating in this current era of uninspired automotive design where it seems like mfgrs take a single car model, open it in Photoshop, resize by 50/70/110/130%, slap on new badge and call it a day. Audi & Subaru are some of the worst modern offenders here.
The LFP is also super cheap, and the NMC are expensive (C in NMC stands for Cobalt which is $$$). You can get 1000km in range with any chemistry, probably even lead-acid if you make it heavy enough. NMC life is fine, but it's just expensive/impossible to get. Tesla et al are trying to pass off LFP as acceptable, almost all Chinese EVs have LFP, but it's super heavy (F stands for Iron, which is heavy). Might be OK if it's flat where you live.
When the sodium batteries come out, it will be a similar story, sodium having an atomic mass of 11 vs. lithium's 3.
Anode-free is an interesting new direction, will be interesting to see if they can address the dendrite growth (dendrite growth causes short-circuit, thermal runaway and fires several months or years into service life and is notoriously hard to test for, because you might need to test for a decade under all sorts of conditions in order to see if dendrite growth occurs).
If you have the cash, NMC is certainly the better tech. If you want a cost-effective EV, the Chinese have figured this out already (LFP). Mixing them, well, it's somewhere in the middle!
A 1000km EV range is not news. Aptera is winning the 'range war' with a 1000 mile (1600 km) EV. And recent battery news should be taken as 'new ice cream flavor discovered' announcements. What is the actual interesting bit of news here? Their proprietary BMS doing DC to DC seems somewhat trivial.
I watched a youtube video on this recently, and I believe that they never mentioned battery lifetime in it. This article said that one of the chemistries only lasts a few hundred cycles, but, because of the use pattern of the dual chemistry is "expected to last the lifetime of the vehicle".
I really hope this turns out well, but given the current lack of specificity, I'm going to guess that overall pack longevity is going to be the Achilles heel of this battery.
Always happy to see people trying innovative new ideas though. Most of them won't work, but we can only find the ones that do if someone tries it. Hope this one turns out better than I fear.
How do the charging times compare? That’s the deal maker/breaker for long road trips greater than 500 miles, or shorter trips where you use all the accessories, encounter lots of hills, etc not possible on a dynamometer.
This. I've done 4 3000km road trips in an EV. I never went more than 200 miles between charging sessions because my family and I need to eat, sleep and toilet. So more range wouldn't have made the trip any quicker. Faster charging would have.
Add a bit of margin and I believe that 300 miles is the point at which charging speed becomes more important than range.
Well, I really think 500 miles is too high of a lower bound, but when you reach 1000 km, it stops mattering again. This is about how long you can travel before stopping to rest.
This would do that trip without a charge stop, so it doesn't really matter? Even if your trip is 1000 miles, surely you could find 30 minutes to stop along the way?
This seems like cool technology, but I can't help but to believe that people are concentrating on the wrong problem. Range is important up to a point, but the more important problems to solve are 1) a recharging infrastructure that makes it so that EVs don't need such huge batteries in the first place and 2) recharge speed needs to be at the level of plug-in, use the bathroom, un-plug and go.
Recharge speed is there already. 20 mins is enough to get 2 - 3 hours worth of driving. We just need more of these fast chargers rather than lots of slow ones.
Considering I charge at home I actually save time overall vs filling up my old diesel in daily driving so stopping every 2 - 3 hours is fine for occasional long trips. Also I spend about 1/5th per mile too.
Most people coming from an ICE get hung up on the range however. They think they need something that does what they have already.
>The Gemini pack also includes a proprietary battery management system and DC-DC converter to enable the NMC cells to replenish the LFP cells as they get depleted.
lallysingh|2 years ago
HPsquared|2 years ago
It leverages the fact that most people make a large number of short trips, and a smaller number of long trips.
Also if it's modular enough, this design could allow replacing one or the other battery if the user does lots of short trips, or lots of long trips.
Also could let the manufacturer do market segmentation, e.g. a high performance model with no LFP, and both parts of the "high-performance" chemistry - and a base model that's 100% LFP.
keenmaster|2 years ago
tromp|2 years ago
[1] https://en.wikipedia.org/wiki/Mercedes-Benz_Vision_EQXX
rasz|2 years ago
kirse|2 years ago
Between EVs and crossovers we're suffocating in this current era of uninspired automotive design where it seems like mfgrs take a single car model, open it in Photoshop, resize by 50/70/110/130%, slap on new badge and call it a day. Audi & Subaru are some of the worst modern offenders here.
acyou|2 years ago
When the sodium batteries come out, it will be a similar story, sodium having an atomic mass of 11 vs. lithium's 3.
Anode-free is an interesting new direction, will be interesting to see if they can address the dendrite growth (dendrite growth causes short-circuit, thermal runaway and fires several months or years into service life and is notoriously hard to test for, because you might need to test for a decade under all sorts of conditions in order to see if dendrite growth occurs).
If you have the cash, NMC is certainly the better tech. If you want a cost-effective EV, the Chinese have figured this out already (LFP). Mixing them, well, it's somewhere in the middle!
1970-01-01|2 years ago
jgalt212|2 years ago
MostlyStable|2 years ago
I really hope this turns out well, but given the current lack of specificity, I'm going to guess that overall pack longevity is going to be the Achilles heel of this battery.
Always happy to see people trying innovative new ideas though. Most of them won't work, but we can only find the ones that do if someone tries it. Hope this one turns out better than I fear.
unknown|2 years ago
[deleted]
russfink|2 years ago
bryanlarsen|2 years ago
Add a bit of margin and I believe that 300 miles is the point at which charging speed becomes more important than range.
marcosdumay|2 years ago
_ea1k|2 years ago
natch|2 years ago
TheLoafOfBread|2 years ago
instagib|2 years ago
Next, make the vehicles cheap enough by some means that we adopt electric vehicles faster.
bwanab|2 years ago
thebruce87m|2 years ago
Considering I charge at home I actually save time overall vs filling up my old diesel in daily driving so stopping every 2 - 3 hours is fine for occasional long trips. Also I spend about 1/5th per mile too.
Most people coming from an ICE get hung up on the range however. They think they need something that does what they have already.
jaredhallen|2 years ago
Joking aside, though, that's a tough problem. It's just an awful lot of current.
xnx|2 years ago
621 miles
cubefox|2 years ago
aimor|2 years ago
mhb|2 years ago
numpad0|2 years ago
0_____0|2 years ago
>The Gemini pack also includes a proprietary battery management system and DC-DC converter to enable the NMC cells to replenish the LFP cells as they get depleted.
nortonham|2 years ago
thebruce87m|2 years ago