Will1991

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^ Didn't you mention ultracapacitors could allow for meaningful discharge (propulsion power) rates? Why do you think charging longer than a few hours is a chore? I know it's inconvenient but I'm all for safer battery with higher energy density even if the charge rate sucks.
Small C-Rate doesn't bring longer charging times, it also reduces power output.

Imagine a 50kWh battery (similar to UX300e) with a 1C charge/discharge rate, it would have (or keep since Lexus isn't pushing for more) a maximum DC charge rate of 50kW and it would take 1 hour to charge. The same battery would allow only a 50kW electric engine as well... It would require Lexus to get a 150kWh to get the same power output as UX300e has.

Capacitors would allow for higher peaks, but they don't hold as must charge as LiON batteries...

And I agree with you, safety should be paramount, as I didn't knew how violent a thermal runway/crashed battery could be:

 

internalaudit

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Small C-Rate doesn't bring longer charging times, it also reduces power output.

Imagine a 50kWh battery (similar to UX300e) with a 1C charge/discharge rate, it would have (or keep since Lexus isn't pushing for more) a maximum DC charge rate of 50kW and it would take 1 hour to charge. The same battery would allow only a 50kW electric engine as well... It would require Lexus to get a 150kWh to get the same power output as UX300e has.

Capacitors would allow for higher peaks, but they don't hold as must charge as LiON batteries...

And I agree with you, safety should be paramount, as I didn't knew how violent a thermal runway/crashed battery could be:

So the current li-ion in the UX300e has 3C (and that determines both charging time and discharge/power? Got it.

But if its double the energy density, then wouldn't the same size accommodate a 100kWh battery? I wonder why SSB's have low C, perhaps it has everything to do with the solid electrolyte.
 

Will1991

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For the UX300e should be around 3C for discharge and 1C for charge, since it’s able to provide a 150kW for the electric engine and 50kW DC charging (on a 54kWh).

I believe (@ssun30 correct me if I’m wrong please) being a solid eletrolite it just “Harder” for the electrons to flow trough... Making it harder to get higher C’s. It’s easier to flow trough liquida than solids.
 

internalaudit

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From ssun in Jan 2019. I don't think power is an issue for SSB's. It's the charge rate. Ssun doesn't seem to suggest that a low charge/discharge rate means lower power output, he said, "you cannot have a battery that has both high power density and high energy density at the same time, so there is always a compromise to be made". He didn't say power but power density. :)

One important metric of a traction battery design is the "C-rate", which measures the rate at which the battery can be charged/discharged relative to its capacity. It's a reciprocal value so a "1C" battery will discharge its entire capacity in 1 hour, while a "10C" battery discharges in 1/10 hour or 6 minutes. It is also the ratio of (the numerical value of) power to capacity. So a 1C battery with 60 kWh will have 60 kW power while a 20C battery with 1 kWh will have 20 kW. Now you see why HV/PHV/BEV battery designs are all different:

For an example, a HV may only have a 1.5 kWh battery pack but requires 30 kW of power, so it needs a "20C" design. A PHV may have a 10 kWh pack but needs 80 kW requiring an "8C" design. Finally, a BEV may have a 60 kWh pack with 120 kW requiring a "2C" design. The rule is that you cannot have a battery that has both high power density and high energy density at the same time, so there is always a compromise to be made. The highest C-rate batteries are those used on LMP1 race cars, which I think have close to 50C (they can discharge their entire reservoir in less than a minute).

So the reason why PHV batteries have high power density is that they have low capacity, thus necessitating higher C-rates to make the car drivable. The consensus in the industry is 15-20 kWh and 80-120 kW power from the battery pack to cover most people's commute everywhere in the world. The reason why BEV batteries have high energy density is obvious: electricity is the only prime mover so they need to squeeze in as much capacity as possible. Of course, nobody says you can't build a PHV battery using BEV cells, but then you get a car with less than 50 hp: it is not going to climb out of an underground parking lot.

You may have noticed there is a caveat here: since most BEV batteries are 2-3C, they will take at least 20-30 minutes to charge even in an ideal setting, and that is unlikely to change in the next decade. Those "1 minute" or "5 minute" chargers the media make so much fuss about are completely impractical and will destroy any BEV's battery after a dozen cycles and are a huge safety concern as well. These ultra fast chargers are only useful for PHVs that can sustain much higher charge/discharge rates.
 

ssun30

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Actually the Li-ion batteries we have today only get 3C+ for a short duration like 10-30 seconds. This is constrained by cooling and how much risk the manufacturer is willing to take. That's why the power war between Tesla and VAG is stupid. For most manufacturers 3C is the maximum they want to go. (I have to say I was surprised that the LF-30 has a 105kWh battery with 400kW or about 4C, but that's a few years down the road so technology is expected to improve by then)

The continuous C-rate for most Li-ion batteries is actually around 1C which means about 30-40 minutes to charge up to 80% SOC. If SSBs could reliably operate at 1C then the actual charging speed will be faster since they have two or even three times the energy density. The effective charging speed (which has same unit as speed, with unit in km/h or MPH) will be much higher. This means a SSB-equipped car will get more mileage within the same period of time, even if the time to full charge is longer.

The real challenge is getting to 1C and that will still require several years of research.

For high power applications like luxury and performance cars, a supercapacitor bank for extra boost is almost mandatory.
 

ssun30

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Let's dial back our daydreams about solid-state batteries and look at some short-term advancements that could be heading towards future Toyota/Lexus EVs.

As you probably know, Toyota has the biggest battery partnership for its future EV lineup, striking deals with Panasonic, CATL, and BYD, three of the largest battery suppliers in the world. Yesterday, Toyota finalized the deal with BYD to create its third JV in China: BYD-Toyota. The JV will focus on BEVs only. Toyota will be producing BEVs based on BYD's e-platform and co-develop battery technologies.

Why is this JV so interesting? It's because of BYD's choice of battery chemistry. BYD has been the biggest proponent of the tried-and-true lithium iron phosphate (LFP) chemistry and is by far the largest manufacturer of LFP batteries. The main advantage of LFP vs. NCM (nickel-cobalt-maganese) is safety and cost:

>> NCM chemistry could undergo thermal-runaway at as low as 200 degrees C. While LFP is stable up to 500 C.
>> NCM will explosively destruct after thermal-runaway, with heat ramping up extremely fast leaving passengers little time to evacuate. LFPs will burn gradually with milder heat generation.
>> NCM cost is very unstable due to vulnerability of Cobalt supply: 60% of world's Co is produced in DR Congo, making it a conflict resource. LFPs only require good old iron. LFP is up to 30% cheaper per kWh.
>> NCM accounts for 86% of EV fires in 2019, whereas LFP only accounts for 7%. That is a number that's hard to dispute.
>> LFP batteries have twice the durability of NCM (over 3,500 full cycles vs. less than 2,000) at similar C-rate.

On the other hand, NCM is significantly more energy dense than LFP, which is the main reason most of BYD's competitors have moved to NCM. BYD's insistence on LFP is due to its heavy involvement in the commercial EV market: most of China's vast electric bus and taxicab fleet uses BYD's LFP batteries, due to their excellent reliability and low cost. Compared to LFP:

>> NCM532 (most mature) is 20% denser.
>> NCM622 (the new mainstream) is 40% denser.
>> NCM811 (the cutting edge) is up to 75% denser.

However, BYD recently introduced the 'blade battery' format. Basically, it's a very thin, blade-like battery cell up to 60 cm long but only 2 cm thick. This drastically increase its energy density and through cell-to-pack (CTP) packaging, BYD's latest LFP battery packs has comparable energy density to a typical NCM622 pack. Compared to cylindrical and prismatic cells, the blade format is much easier to adopt CTP. BYD also claims the battery lasts over 1.2 million kilometers.

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In third party testing, the new blade LFP battery is proven to be by far the safest, surviving the piercing test with no explosive thermal run-away after one hour (the surface is only lukewarm). The NCM cell suffered explosive failure within seconds while a regular prismatic LFP cell caught fire in less than a minute.

The new blade battery will be used on BYD's flagship Han BEV with similar size to the Tesla Model S. It has a 550kg pack with 77kWh, for a energy density of 140Wh/kg. The car starts at just RMB 300k ($ 43k), undercutting even the 50kWh TM3. It also looks stunning:

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Now this development will not suddenly make LFP competitive since both CATL and Panasonic have developed NCM811 packs using CTP that achieve nearly 200Wh/kg, maintaining the 40% energy density advantage. It is worth noting, however, that these packs resorted to full aluminium construction to reduce weight, and we know what aluminum plus fire means.

Given Toyota's obsession with safety and reliability, I fully expect them to source LFP blade batteries from BYD, maybe even for Lexus vehicles. The bigger advantage here is cost savings, as BYD estimates the new format to reduce cost to 50% of NCM packs at the same capacity.
 
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ssun30

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I have to say I like Toyota's route of building massive coalitions to have the healthiest supply chain possible instead of rushing out products in panic. Currently they have three battery suppliers: Panasonic pushing the cutting edge, CATL providing the biggest capacity, and BYD offering the safest choice, so they get to choose from three good options to spread out the risk. They also have three platform-sharing agreements: E-TNGA with Suzuki/Subaru/Mazda, GEP with GAC, and e-Platform with BYD (four if we count the 'common FCV platform' shared with Geely, FAW, and SAIC). This is a much healthier long-term strategy than competitors who are just piecing together commercial off-the-shelf solutions like Lego.

Toyota 'purists' may not like this strategy, but this way they are on track to become the largest EV producer in the upcoming decade. It all comes down to execution, as I would imagine such a huge coalition would be a very hard to manage compared to a full vertical integration strategy like Tesla.

I would still say Tesla is the long-term leader unless Elon Musk makes stupid stubborn investments like the Semi again. And I expect Toyota to be best of the rest.
 
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ssun30

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i only comment on information I already know. My answer to your SSB questions have always been: they are many years away, nobody is ahead because none has left the lab. The focus now is improving existing chemistries and designs.

CATL projects NCM growth potential to 350Wh/kg cell-level by 2023, which is 80% of projected energy density of first-gen SSBs. That's nothing to scoff at. LGChem and Panasonic are pushing past 300Wh/kg in the next couple of years as well.
 

internalaudit

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LMP SSB is out on the road. It says right on Blue Solutions website and I know they have a car rental operations in the US but that could have been shut down already because range isn't so good.

Good to know it makes a whole lot of sense to wait for li-ion batteries to improve unless one needs to buy a BEV now or soon.
 

Will1991

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At 140Wh/kg is not far off from our UX300e at around 160Wh/kg using NCM622, and I can't argue with more safety and more durability!

And at 77kWh, it's more than enough if the car has proper aero and efficient motors which can be achieved easier with a dedicated BEV platform.

Do you have any information about charging rates?

I do understand the need for improved energy density, but in my opinion, given current energy densities it's much more important to increase safety and reduce cost... With a currently improving charging network, ever bigger battery packs won't be needed.
 
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ssun30

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There are no charging rate info on the Han. BYD only uses the standard GB/T 2015 which has a nominal power of 60kW.

The Han EV AWD has peak power output of 363kW/486hp and does 0-100 km/h in 3.9s (for less than USD 50k). That's about 5C which is pretty typical for LFP batteries. High C-rate is another advantage of LFP.

NEDC range is 605km for 2WD and 550km for AWD. Energy consumption is 14.1 kWh/100km, very impressive for a full-size sedan. Model S is at 17.3 kWh/100km.
 
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internalaudit

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@Will1991 , what are your criteria to pull the trigger on a BEV? :)

It seems giving Toyota two to three more years makes sense. Forget about the UX300e or get one used three to four years down the road.

Like I said, SSB is already available but Ssun is correct in that other technologies like LFP and li-ion NMC are also making good progress:
:)
 

Will1991

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Safety, reliability and durability are major concerns for me and for general specification:
-> 320km highway range at 120km/h
-> CCS DC charging at 100kW
-> Around 7 sec. 0-62mph
-> Sedan
-> Priced around 50.000€ in Portugal (Current IS goes from 43~55.000€)

I know this is basically a Model 3 SR+, but I'm not really into Tesla's as much as I would like to, and I honestly believe I would be happier driving my old Avensis than a Tesla. Even my fiancé agrees with me... We sometimes joke around with her buying a Mercedes BEV (pending how the next year or two goes for us, she might trade her 2015 A-Class for a EQA) before Lexus/Toyota offers one.

From safety, reliability and durability I think we're safe with the UX300e, even range shouldn't be very off... But yes, I'm not seeing me buying it because I don't like SUV's and I've some difficulties understanding this big price premiums so many people pay for them... I think I've said this here before, but here in Portugal it's crazy how a UX250h is more expensive than the much better looking, bigger and more powerful IS300h.

Do you have similar criteria?
 

internalaudit

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I have similar criteria.

Except, it gets much colder here in Toronto, Ontario, Canada than it does in Portugal so I will need realistically around 300 km range (during the warmer winter days, on super cold winter days, wife can take another car) to cover subsequent degradation of capacity. She plans to retire in 2030 and we may no longer need a minimum of 250 km at that time but then again, BEVs maybe be hitting the 600 km by then.

I don't care much about fast charging because I'm not getting rid of all our ICEV/HEVs, likely just one of them (whichever is least reliable) but I guess 100 kW is good enough for emergency top ups. Heck, I probably would be able to live with 50 kW but it depends on my wife's usage. She drives out more until this virus struck.

7 seconds is good enough for me but it seems that is a given :) :

I prefer a sedan but my wife prefers a SUV. With torque vectoring, I'm good with a SUV the size of a Macan/Q4 e-tron (happy wife happy life). I don't like anything too big since that just means bigger battery, heavier weight and less range or higher price overall. We are below average in terms of height and dimensions -- the four of us can fit in the CT200h.

$80k CAD (now worth a lot less in USD) is likely my max before taxes but of course, the lower the price the better. I really think I want electric motor torque vectoring but of course battery quality and overall build quality are still more important than TV but I have read that it also makes it safer to drive on wet roads or when tires are traveling on surfaces with varying coefficient of friction.
 

Will1991

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It's quite unusual for us to get bellow 0 Celsius, even at my parents city usually less than -3 is achieve only couple of days.
If we got so much snow as shown in your pictures from your CT... Our country would stop, even our "snow heaven" called Serra da Estrela, usually authorities start closing down roads if it gets too much snow ahahah

I want to drive it across Europe so a faster charger rate does make a big difference, even more than a bigger battery as we usually take a break after 300~350km for a cup of coffee on longer drives.

Torque vectoring on icy roads should improve safety, but is such a novelty product, the cheapest ones should be the next Q4 e-tron SportBack and a Lexus RCF, this later being a whole different beast.
 

internalaudit

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^ True. Much more to see in Europe. It's mostly a cookie cutter approach in most of North America, except for select tourist attractions (US is good with that) or natural wonders.

I think Honda has proven that electric motor torque vectoring is not hard to implement. It has it on its 2016 NSX/MDX/RLX sports hybrid and for most people who know what TV is (I haven't driven one but I know what the fuss is all about) who've test driven these vehicles, they've been quite content with the MDX and RLX cornering capabilities although their chassis and suspension are not geared towards canyon carving like on the NSX.

Electric motor TV software may even be easier to implement because it's just varying the electric motor torque depending on how all four wheels are moving.
 
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internalaudit

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I think Acura botched the TLX with the 9-speed ZF transmission and even it's own-speed DCT.

It seems the SH-AWD adds a lot of cost and they took that out of the previous gen RLX, which was probably a bad move.

Then the RLX is just too big a sedan for most buyers. Buyers don't mind driving humongous SUVs but don't seem to want big sedans lol.

Had they put the SH-AWD on the ILX, it would have differentiated it from the Civic, and would likely be a winner but most likely at the expense of TLX sales.

I still haven't given up on Honda. Issues with current ones are mostly engine-related (1.5T oil dilution with fuel) and like what people (myself included) are saying here on another discussion thread, the combination of just three or four electric motor sizes will provide a lot of flexibility when building the entire BEV line up. Honda was and still is a motor company but they've got to realize what a jewel their SH-AWD is and that they can still build great cars that are praised by many subject matter experts.

I just realized that double wishbone suspension does trump most Macpherson strut set ups (contact patch with the ground for cornering abilities) but then there are other components besides these that make the entire cornering experience.
 

internalaudit

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Interesting. I think 600 km between charging is mighty plenty. Toyota also going lithium sulfur route, correct?

 
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