China's top EV battery maker announced a breakthrough, but top boffin isn't convinced
- Reference: 1692849750
- News link: https://www.theregister.co.uk/2023/08/24/catl_battery_claim_questionde/
- Source link:
CATL [2]claims its battery, called Shenxing, is the world's first superfast charging lithium iron phosphate (LFP) battery and that at full charge it enables a range of 700km (435 miles).
By way of comparison, the average EV range in the US last March was calculated by [3]Bloomberg at around 470km (291 miles).
Much critical information is missing in the CATL claims
And according to the US Department of Transportation, typical home, workplace and public level 2 chargers can take a battery from full to empty in anywhere from four to ten hours. Direct current fast chargers in places like highway corridors can reach 80 percent charge in ranges between 20 minutes and one hour.
Batteries with the specs claimed by CATL matter because buyers worry that electric cars may be less convenient that gas-guzzlers.
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Studies, like one released last week by consumer intelligence agency J.D. Power, also [5]cite a lack of charging infrastructure and price as factors influencing purchasing decisions.
[6]
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CATL knows this and in its announcement of Shenxing stated "Currently fast charging anxiety has become the top factor that stops consumers from shifting to EVs."
To better understand the significance of CATL's claim, it helps to revisit how these batteries work.
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In thier simplest form, they involve moving lithium ions from a cathode to an anode through an electrolyte, creating a potential difference between the two electrodes. When the stored energy is used, the ions return to the cathode. And repeat.
It's also important to remember that batteries are temperamental: as they approach full charge, progress towards full storage potential slows.
Shenxing is claimed to reach 80 percent State of Charge (SoC), at the ten-minute mark, at which point it stores enough energy to propel an unspecified car for 400km at unknown speed. That performance may not always be possible, because at lower temperatures charging can take longer.
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CATL did not say how long it takes to charge the remainder of the battery.
Shenxing is an LFP battery, which has a wider tolerance for overcharge than old school EV lithium batteries. They can also run at higher temperatures – which is good if you want to charge fast, because that process generates more heat.
CATL claimed Shenxing employs "innovation in material and electrochemistry and system structure," which just about sums up the discipline of battery engineering.
[10]Chinese battery maker for the stars of the EV world suddenly wants to be seen powering human rights
[11]Boffins interrogate sodium ion battery stability mystery
[12]Nikola recalls electric truck fleet over battery fires
[13]Chinese company claims it's built batteries so dense they can power electric airplanes
Specifically, the battery-maker said it sped up the extraction of lithium ions by leveraging "super electronic network cathode technology and fully nano-crystallized LFP cathode material."
It also claims to have modified the properties of the graphite surface in the battery to increase the number of channels the ions can flow in and decrease the distance they need to flow – creating what it called an "expressway for current conduction."
The electrolyte formula, the fluid the ions move through, also got a reduced viscosity that improved its conductivity apparently. The film formed on the surface of the anode during the first charge and discharge of the battery was also claimed to be improved, to be less at odds with ion movement.
An improved coating on the electrolyte and separator is said to help control the temperature inside the cells, thus mitigating typical problems brought on by fast refueling and allowing it to operate outside what would normally be safety limits.
The battery market is super-competitive, so CATL is not being evasive by offering only broad info about its tech.
But one notable omission is a spec for energy density – the measure of stored power compared to weight – other than the word "high."
Energy density matters because nobody wants heavy batteries, which is why many were excited when, in April 2022, CATL [14]announced a 500Wh/kg airplane battery. That density suggested electric aircraft could fly.
Most EV batteries boast energy density of around 260 to 270Wh/kg.
CATL's predecessor to Shenxing, dubbed Qiling, came in two variants. A model using Nickel Manganese Cobalt (NMC) tech claimed energy density of 255wh/kg and the LFP model boasted 160wh/kg. CATL asserted 1,000 km range was a possibiity.
Yet the company has offered only the broad explanations above for how Shenxing uses LFP tech to achieve swift charging and long range, qualities that suggest better density.
Dr Rachid Yazami, [15]inventor of graphite anode , a key enabler for Li-ion batteries, is therefore suspicious.
By enail, he told The Register "If the CATL claims are true, this would be an unprecedented enhancement in the battery energy density for the last 30 years."
The professor and scientist said he is skeptical of claims that CATL has achieved density to match its claims of range and charging speed, and of CATL’s 500Wh/kg airplane battery.
"Much critical information is missing in the CATL claims, such as the cycle life of their batteries which converts to total life miles driven by the EV, the extreme temperatures performances, safety and costs," added Yazami.
Another consideration is that while the battery corp is a leader in NMC batteries, CATL has much less experience to rely on for innovation when it comes to the [16]currently trending LFP batteries.
Another unknown is whether CATL accomplished Shenxing's claimed peformance in prototype batteries, or units it could mass-produce. The Chinese company has promised it will have the batteries in mass production by the end of 2023 and inserted in EVs by Q1 2024.
"Thanks to its strengths in extreme manufacturing, CATL has achieved the ability to rapidly transfer technology from lab to market, enabling rapid mass production of the Shenxing battery," boasted the firm in its press release.
The Reg hopes whoever takes the first Shenxing-powered cars for a spin isn't in a rush to test the company's claims. ®
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[1] https://www.theregister.com/2021/06/14/rachid_yazami_the_future_of_ev_batteries/
[2] https://www.prnewswire.com/news-releases/catl-launches-superfast-charging-battery-shenxing-opens-up-era-of-ev-superfast-charging-301902663.html
[3] https://www.bloomberg.com/news/articles/2023-03-09/average-range-for-us-electric-cars-reached-a-record-291-miles
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2ZOcqQ9U0D4IbQ-6EyPfyOgAAA4Q&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[5] https://www.jdpower.com/business/press-releases/2023-us-electric-vehicle-experience-evx-public-charging-study
[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZOcqQ9U0D4IbQ-6EyPfyOgAAA4Q&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ZOcqQ9U0D4IbQ-6EyPfyOgAAA4Q&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZOcqQ9U0D4IbQ-6EyPfyOgAAA4Q&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[9] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ZOcqQ9U0D4IbQ-6EyPfyOgAAA4Q&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[10] https://www.theregister.com/2023/07/12/catl_un_global_compact/
[11] https://www.theregister.com/2023/05/15/boffins_bust_sodium_ion_battery/
[12] https://www.theregister.com/2023/08/15/nikola_recalls_its_electric_truck/
[13] https://www.theregister.com/2023/04/20/catl_dense_batteries_for_planes/
[14] https://www.theregister.com/2023/04/20/catl_dense_batteries_for_planes/
[15] https://www.theregister.com/2021/06/14/rachid_yazami_the_future_of_ev_batteries/
[16] https://www.reuters.com/business/autos-transportation/ev-batteries-lithium-iron-phosphate-narrows-gap-with-nickel-cobalt-2023-06-22/
[17] https://whitepapers.theregister.com/
Re: Another week, another astonishing claim from some other Chinese institute
OTOH, why deny a Chinese institute something that has worked so well for Musk? FSD, anyone? Bulletproof glass?
Wait, batteries are rated in km?
It's great we don't have to worry about the mass of the car, driving conditions, driving style or charger power any more.
Lithium Titanate batteries charge like stink. The downside is they aren't as energy dense as LFP. Fine for a bus, not as good for a passenger car. Other types of Li batteries are less prone to self-immolation and further types are great for lots of cycles. It's going to be a combination of traits that makes for the best battery for a particular application.
When people are looking at speakers they'll be impressed by lots of power handling as the sole criteria, which is silly. I could glue a voice coil made from a coat hanger to a Lead cone and have a woofer capable of absorbing all sorts of power until the Lead melted. Other than the melty cone, the sound output would be pretty feeble and the frequency response would be very limited, but 3kW of power handling shouldn't be an issue. Oh, did you want lots of sound for that power? Hmmm, maybe some other factors such as efficiency are important too. If size isn't a big constraint, I can offer some plans for a subwoofer that will rattle the neighborhood with a very modest power input. In the days when a 50W amplifier was a monster topped with glass tubes and the ability to heat a cinema, efficiency was super important.
The moral of the story is to not get too fixated on one metric while ignoring others that can be just as important.
Re: Wait, batteries are rated in km?
At least with public transport systems the battery type can be picked to suit the planned usage, for private cars the battery type will be a trade off tending towards the cheapest that gives the initial 'Range X after Y mins'*.
The average bus also has the advantage of being big enough that simple battery pack swap outs can easily be accommodated in the design, potentially making vehicle charging a moot point for a fleet operator. A return to the past when the bus sales bod would offer a range of engine options from different manufacturers.
*at the end of any warranty period if you're lucky!
I thought the US liked battery cars...!
Quote...
And according to the US Department of Transportation, typical home, workplace and public level 2 chargers can take a battery from FULL TO EMPTY in anywhere from four to ten hours.
Re: I thought the US liked battery cars...!
"And according to the US Department of Transportation, typical home, workplace and public level 2 chargers can take a battery from FULL TO EMPTY in anywhere from four to ten hours."
When talking about anything coming from a government agency, there's no end to how things can get screwed up.
I don't think that my brain could ever construct a sentence with the word "charger" and "Full to Empty".
It's even more silly when most EV owners don't drive their cars until the battery is flat any more than people will challenge the fuel gauge gods and wait until the needle is well and truly on the E before buying petrol. People charging at home/work/shopping will plug in if they are leaving their car parked and there's an open spot. A really slow set of L2 chargers at a train station is a good thing if people are commuting by train and will be parked up for 9+ hours at a time. If those are cheap, they'll likely fill up first. If you have off-street parking at home, slow is fine too and means it can be easier to provision.
Re: I thought the US liked battery cars...!
If you plug it into two at a time, can you double that rate?
at lower temperatures charging can take longer.
If you're shoving that much energy into a battery in 10 minutes, I don't think low temperatures are going to be the problem
Lifting the charging cable might be more of a problem for some people.
Chunky!
With the voltages required to haul that amount of power I don't think you need a cable.
Just stay out of the way of the lightening bolts..
J.D. Power, also cite a lack of charging infrastructure and price as factors influencing purchasing decisions.
I own an electric car. Whilst the amount of chargers and their prices are issues, they're not the number 1 problem for an electric car driver. It's the availability/reliability of chargers that's my biggest worry on longer journeys.
If I can guarantee getting to a charger and it working and being able to use it in a timely manner (i.e. not having to wait an hour or more before I can plug in) planning longer trips is much less stressful. At the moment, I work on the assumption that my prefered charge point won't be working and plan backup locations.
Some of the newer motorway service stations have large rows of chargers, but some motorway service stations have just two chargers.
I see in quite a lot of supermarkets and even hospital parking that charging spaces are taken by EV's, but they have not plugged in to charge.
Its as if they feel, these spaces are for EV's regardless of if I need to charge, so I will take it and leave the poor sucker who is coming here and needs to charge no where to go
I've heard that Tesla have a rule that if you don't move your car within something like 10 minutes of your charge completing, you start getting fined.
every few days it seems some company or other announces amazing battery improvements.
But in the real world, actual real improvements are small and pretty much insignificant/tiny overall, due to chemistry and physics unless some completely unknown material with very weird properties is found, we are stuck with approximately what we have now, there will be tweaking at the edges (main due to balancing the charge rate/temperature/cycles/exploding in flames factor) but nothing profound or earth changing.
(and for tesla fan twats, musky made a new battery with 50% more charge with the brilliant method of making the battery 50% larger, pure fucking genius con)
"...in the real world, actual real improvements are small and pretty much insignificant/tiny overall, due to chemistry and physics..."
The theoretical chemistry predicts battery capacities of well over 1kWh/kg, and current thinking is that producing real-life batteries of almost 1kWh/kg could be achievable. There's a lot of research money in this area, and capacities have been rising pretty quickly over the last 10-15 years - real-life (ie in commercially sold cars) density has increased from about 100 to 250 Wh/kg, which is approx 10% per year improvement. That is absolutely not small, insignificant or tiny.
I get that the article is more about charge times than energy density, but these have also been improving hand-in-hand with energy density.
In practical terms, I also get why the new emphasis is on charge time rather than energy density. For an EV anything above 250Wh/kg is a bonus, since 125 kW is a huge battery size and EVs are already perform fairly well with half-ton batteries. OTOH, being able to top up your 'tank' in 10 minutes would bring EVs almost totally on par with ICEs for convenience (as long as the charging infrastructure is there of course)
Charging is only part of the equation
Even if we DID have enough charges and an ability to charge that quick, the problem is that the power grids are nowhere near ready for delivering that amount of power - they already have a job keeping up with companies switching to electric power. I know that there's a stop in the Netherlands, for instance, of adding new industrial clients to the network as it's basically at capacity and fixing that isn't done overnight.
It will happen as the demand exists, but not quite at the speed that current proponents predict.
Re: Charging is only part of the equation
I saw a program the other day where a new charging station actually had its own batteries to smooth out the load on the grid.
Narrowing down the claims...
Taking a reasonably efficient EV doing 0.15 kWh/km, we're talking 60kWh of charge in 10 min for a battery that has a full capacity of 105kWh, for 700km total range. 60kWh in 10 minutes requires charging power of 360kW (technically a bit higher due to charging inefficiency). If (as is likely) there is some marketing 'taking-the-piss' and using the 400km claim for a super-efficient unloaded EV under optimal (and unrealistic) conditions, and in real-life conditions it would only really add 300km, then that's 45kWh of charge in 10 min for a battery of just less than 80kWh and total range 525km (which, incidentally, is far closer to the capacities in real-life batteries). That would require charging at 270kW average.
Chargers already exist that can deliver 350kW, although that doesn't mean the battery can handle charging at that power. Having said that, the Hyundai Ioniq 5 (which was introduced in 2021) with 800V charging is already achieving real-life charging power of about 160kW average and 220 kW peak. (Source: https://electrek.co/2021/10/22/electric-vehicle-ev-charging-standards-and-how-they-differ/ + linked article re Hyundai Ioniq). The company claim they will have the battery in cars by 2024 (3 years from introduction of Ioniq)
Bottom line, it's fairly likely that rather than absolute bullshit, it's a reasonably strong (but predictable given 3-year lag) increase in charging power, which is certainly to be applauded, but which has also (equally predictably) been over-hyped by their marketing.
Charger power rating
Quick calculation - EVs seem to get around 6..7km to the kWh, so 400km would require at least 60kWh of charge. To get that in 10 minutes would mean a charge rate of 360kW. Even the fastest chargers don't currently get anywhere near that. And I believe the highest charging voltage currently in use is 800V, at which 360kW translates to 450A, which would need a rather hefty cable and connectors. None of this is insurmountable, but it's going to need a lot of infrastructure improvements to make this new battery technology viable.
Another week, another astonishing claim from some other Chinese institute
At this rythm, by the end of the year they'll be declaring the flying car.