Charging electric vehicles 5x faster in subfreezing temps
news.umich.edu
news.umich.edu
The real claim is 10 minute charging of lithium-ion batteries with a process which is a minor mod to existing battery production.
There's no product yet.
Batteries with good low temp behavior have many specialized uses. Things that have a small solar panel, a battery, and no grid connection could benefit from this. Even flashlights could use this.
As a side topic, what are the currently available options for this?
I've heard about sodium ion (safer but still not sub-zero charging friendly, also no easily available solar charging controller boards), lithium titanate (same), and plain old deep-cycle lead acid.
For small solar-powered projects, it would be nice if there was a power bank on market which supported solar charging, and could either be safely charged in freezing temperatures, or had built-in temperature sensor and reject charging when it's too cold.
Being under ground will prevent both over-heating and freezing assuming your circuit is per spec designed to run cool. This can also reduce tampering. If you are not concerned about serviceability of the circuit board then you can put it in a small enclosure and fill it with epoxy so that the entire thing is water proof. There are epoxies designed to conduct heat but not electricity.
This assumes of course that your setup is meant to be stationary.
[1] - https://www.amazon.com/s?field-keywords=lifepo4+heated
If you are mostly concerned with low-temperature charging you could even power all that from the charging side only.
https://midsummerwholesale.co.uk/buy/eleven-energy/4-5-kwh-s...
https://www.ttnews.com/articles/byd-5-minute-charging-rivals
BYD would not pump 400 kW into a battery at -10 C. This research helps in the situation where you have a cold battery, and need to start charging it before it can warm up.
Not saying it's impossible, but that won't be easy.
Megawatt chargers? We'll need the generation capacity to support 500,000 of them.
The problem isn't trivial. If you have, say, 10 charging spots on a lot, each requiring a megawatt, how are you going to deliver that? Are you going to build a whole substation for every charging parking lot?
Is that going to change?
In the Netherlands they are partnered with a local green electricity provider (Vattenfall) and Shel for their charger network. Shell owns the most petrol stations along the highways, so they will have their chargers there for sure.
I'm expecting the tariffs on Chinese EVs to be rolled back in EU after the US tariffs. They might want BYD to open local factories, like NIO is planning to do.
I doubt it. This would likely have a significant negative impact on domestic EU car companies, most of which are considered cornerstones of their local country's economy. Now, whether this should happen (to benefit consumers/the environment) is another argument.
They want to pair that with technology transfers, similar to how China forced other companies to do technology transfers when opening factories.
Europe remains to be seen, but also unlikely short term as we're also slapping lots of tariffs on chinese EVs to protect local industries
Neither Europe nor the US can compete with the level of disdain for the environment, labor laws and poverty that China brings to the table. Wages alone make anything made in China so cheap that, for mass-market goods, competing against China (or its upcoming competitors in the race to the bottom) is impossible.
The issue is entirely subsidies at this point.
Labour costs have been steadily rising for the past decades and significant poverty hasn't been an issue for a long time. Emission wise, China is strictly ahead of the USA when you look per capita (unsurprisingly, they are not an oil producer).
China is not in a race to the bottom. Their hdi has been steadily climbing. They are economically more or less in the same position that Japan was in the 80s before the Plaza accord but with less prosperity, on the verge of becoming a developed country.
Which is a moot point because European manufacturers also received insane subsidies form their governments in the past.
The issue is China has been innovating in EVs hardcore for 15+ years while European manufactures kept pushing diesels and cutting costs with their suppliers and were only making EVs to shut up the green hippies, but were never committed to them, and now they've been caught with their pants down unable to compete on price nor on technology.
They got fat, lazy and complacent thinking their brand names would carry them.
There is no external arbiter here to call it even and declare it moot. The WTO was supposed to somewhat be that but has been completely defanged by non cooperation. Every country is sovereign regarding both how it subsidies its companies and how it taxes imports.
The European Union can both support its manufacturers and be unhappy about China doing the same.
> They got fat, lazy and complacent thinking their brand names would carry them.
Sure, but strategic inadequecy of the local companies doesn't necessarily prevent countries from wanting to protect their manufacturing sector. It's a lot of jobs from Germany and the value chain is split between a lot of small subcontractors injecting a lot of money in their local economy.
Having said that, the future is not necessarily a completely black and white alternative between punitive tariffs fully blocking more efficient Chinese companies à la Trump and a fully free market.
There is plenty of space for agreements involving companies partnership, partial technological transfers, bringing part of the value chain closer to the final consumer. China has been really smart at this game with the mandatory JV with a local partner for getting access to their market. Maybe it's time we start using the same playbook.
Why haven't western governments and companies brought this up as an issue when they moved our jobs to China 30 years ago forcing us to buy our stuff but made in China while their profits skyrocketed? And bear in mind Chinese pollution, wages and living standards were way worse back then than today.
It feels incredibly hypocritical for western companies to cry about these things NOW, right when the Chinese companies have started eating their lunch on their home turf, while they rode the gravy train for 30 years. It's almost as if they wanted to have their cake and eat it too but now have to reap what they sow and they don't like it.
Our people loved it for the first few years because a lot of stuff became cheaper (or affordable at all), our governments loved it because now someone else would have to deal with toxic waste, and our companies and especially their owners made untold billions of profit that they were allowed to keep.
By the time China was strong enough to begin the "extinguish" phase of their 20 year economic plan, and the Western nations could no longer hide or deny the issues, it was far too late.
They do reap what they sow. The automotive industry is a victim of its own stupidity. They lobbied for features until the cars became so expensive that nobody buys them.
Dealerships still try to sell people on financing and that makes them so much money.
They also have lower per capita emissions than the US: https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di...
How cool would it be if instead of having to slowly charge the same battery in my EV over its lifetime, I could (say) subscribe to a network of well-kept batteries and easily get a fully-charged one whenever mine gets low? Too bad China is so out of reach for me; though even if it weren't, those battery-swap stations don't really exist here - though I'm sure that's just another artifact of widespread sinophobia.
That's only one example. See these article (or honestly any article) for more:
https://www.investors.com/news/chinese-electric-cars-america...
https://www.carwow.co.uk/electric-cars/chinese
Dismiss it as propaganda if you wish, but it's not like it's fake. The cars they show are real.
Maybe its short sighted of me, but I don't want some abused battery from another owner swapped into my EV. The amount of trust I'd have to place on a battery swap station to give me a battery that's just as reliable/healthy as my own managed battery is far too great. Would they just reject people who try to swap faulty battery's or just take it as an operational loss and recycle batteries that fall out of spec.
Of course a lot of this ties into future ownership/rental financial models, however the world works with everything going towards subscription in the future. If you're just subscription/leasing a car as a service the vast majority of people won't care of give a shit anyway.
As for now I own my EV and when the battery needs replacement ten years from now I expect to be able to buy another one, hopefully larger/more capable, and continue on my merry way.
Chinas secret ? Extremely protective tariffs + very selective smart RND incentives/ investments by government + biggest engineering pool in the world because of outsource to China due to free trade/ no tariffs in US/EU.
It’s a talent pool they built last ~20 years to do outsourcing/offshore policies
If the charge rate is reduced by battery temp and chemistry, shunt the surplus supply into changing the battery temp, no?
For most people, a car is at least the second-most expensive thing they'll ever own -- as well as the most expensive machine they'll ever own. It is also something that many are very unwilling to RTFM for, often to the point of irately defending this unwillingness and the resultant ignorance.
An improved battery that can charge quickly when cold (while maintaining safety and longevity) solves many problems, including some that may be self-inflicted.
3 decades ago everyone with a mobile phone knew that you should never charge the battery unless it's empty. They knew "it has memory" and if you charge it when it's half full it will "remember" that new charge as its capacity. A decade or so later with LiIon or LiPo everyone knew the opposite, never let it go to empty.
Nobody knew why, how, they just knew this is how you should do it.
This would work for EVs too because they're expensive to buy, expensive to replace batteries, and range or charging speed are super huge deals.
I feel that your example portrays the opposite of what you may have intended it to portray.
What actually happened was that people went out of their way to do a thing that not only did not improve the overall longevity of their rechargeable batteries, but may have actually made it worse.
Whatever you want to call it, the damage caused by certain usage patterns existed and was visible to the users. So they learned how to generally maintain the battery of that expensive device to keep it usable for longer. I have no reason to expect people are less capable to do the same for a car's battery, now that everyone is more tech educated and cars are smart enough to tell them what to do and when.
Voltage depression of individual cells seems to correlate more with deep discharges of a battery (perhaps combined with differences in cell quality within that battery) than anything else.
And deep discharges were what people were deliberately doing to fend off the evil spirits of "memory effect" probably made the problem worse.
Not sure what would work for EVs too? I'd suggest education from the ev manufacturer is better (eg by repeating to the driver the first 50 times how and why to prepare for changing), and by the technical means (doint it automatically if possible).
Creating yet another "rule" that will then persist as the downright counterproductive or maybe even harmful myth decades later is not a good solution IMO.
No it doesn't. All it assumes is that some users may want to take steps to solve it and that those users deserve the option. Literally nothing needs to happen to the existing behavior, the automatic preconditioning can still stay.
In my BMW EV we recently got an update and it's now possible to manually pre-heat the battery, not only from within the car, but also even remotely via app. You can even lookup now the battery temperature.
It would be nice if I could figure out some way to just force it on with a switch/aftermarket module talking to the canbus.
That's how EV's currently work. Even those without heat pumps. I can see my E-transit's coolant heater[1] pull up to around ~5-6KW at full tilt battery heating mode when I plug into DC fast charging and its not sufficiently warmed. Cuts off once the HVB hits around 98F.
[1]https://www.proxyparts.com/car-parts-stock/information/part-...
https://electrek.co/2017/08/24/tesla-model-3-exclusive-batte...
I believe the "microscale channels" are a better solution that reduces the amount of heat generated at the connection points of the battery, and also reduces the high temperature gradient at high voltage charging at low internal temps (high internal temperature delta), which I understand to be a primary cause of battery degradation.
This is one of those Great New Technology items that smells like a failure simply because it's not competing with the thing the designers think it is. It's not enough for this to beat a cold battery with a performance delta ("5x", per the article) that would justify its additional cost. It has to beat a battery with a garden variety heat pump attached, which is a much (much) lower cost barrier.
I'd be very interested in seeing what they can provide for us. Improved battery chemistry for use in the far north is of far, far more value than yet another 5 person car for 1 person driving in San Francisco.
I wonder if regen braking going to zero is behind some of the horror stories of sudden unexpected range loss in cold temps.
Exactly! That sounds like a drawback when you state it like that, but what it actually means is that this magic battery doodad needs to provide 90-95% of the performance of its existing, mature competitor (assuming no other drawbacks) just to be break-even in the market. You don't disrupt markets with numbers like that.
The problem is mostly that it does the battery draw when parked.
Solid electrolytes are coming some day soon, so that we can let it freeze without killing the cells.
Right now, the Tesla is hard to use in a winter sport season unless where you're driving has a charger or underground parking near a plug point.
I can drive up hill to a nice ski resort, spend 3+ days taking the bus with all your shoes on without touching the car.
With the batteries, they'll just run down when parked, so I cannot park it for a whole week outdoors like I can do with my Subaru.
And with the low battery + low temps, it will not charge back up going downhill so the expected range drops massively by the time you're downhill.
Once you navigate to a charger, the car starts running the heater and driving down range further.
Watching the car battery eating its own range while driving to "Donner pass road" on your way out of Tahoe or Reno feels rather appropriately horrific.
What kind of clunkers have you been using that lose charge on the 12 volt after just 3 days in the cold? I've occasionally left my ICE car out in the cold for a week without using it and it never once even crossed my mind to worry about whether it would start after that; I've never had that issue on any car built in the last 15 years.
That’s false since at latest 2013 in the US.
The past 12 years of BMW as a counterexample all have thermal management. Tesla too.
You may be remembering the original Nissan Leaf?
I believe the eGolf which was sold in the US shares the same drivetrain and battery.
Perhaps you are changing the topic from your original thermal management to heat pump systems specifically?
Ideally, you don't do that, but when traveling sometimes you have to stay at a place that doesn't have a charger, and it's really cold, and now rather than a 30 minute charge it's more like 90 minutes.
> This is one of those Great New Technology items that smells like a failure simply because it's not competing with the thing the designers think it is.
This technology makes no sense for fast DC charging because there's enough waste heat to keep up the battery temperature, and you can just use some of the power to heat up the battery.
But it can help for slow overnight charging. Keeping battery heated all night is wasteful, but you still want to be able to charge.
You can’t just overvolt out of that - you need an external source of heat until you’re out of the dangerous thermal area.
The charge currents for sub-zero are near zero amps, but are still > 0. It should destroy the cell, but apparently doesn’t?
Any insight?
At least not in a way that people complain about battery failures or degradation. On the other hand, the battery has to reach that temperature in the first place, which may take a couple days of constant exposure to that temperature.
I did some research, and the plating issue happens when charge currents exceed the ability for the battery to absorb them, which dramatically decreases below freezing.
That is why those battery charts show dramatically reduced charge currents (nearly zero) when around freezing.
That data sheet also doesn’t cover cell life in these conditions conditions.
They have very high normal C ratings (hundreds of amps) which is why it is measurable and not actually zero, but reducing it to a couple amps before failure isn’t much different.
If batteries aren’t failing in these conditions, it’s because of some other protective circuit, not because the battery itself is special. It isn’t.
The BMW i3 had inductive heating strips underneath the coolant channels in the battery pack[1]. I know our i3 had a heat pump, I presume both were in play.
We used our i3 down to -25C (-13F) many times, didn't have any issues.
Some do but don't enable it immediately, but do so with a software upgrade. (such as what happened with Kia EV6/Hyundai Ioniq 5)
Edit: downvote me all you want, I was responding specifically to “It has to beat a battery with a garden variety heat pump attached” of which EV heat pumps are not garden variety heat pumps, which do struggle at those temperatures. Didn’t think I had to be so pedantic.
The real benefit, in my view, to being able to charge at cold temps is to improve overall efficiency. If you have to waste some amount of power to heat the battery then that is power that could have been used to charge the car instead...
It's true that there are very cold environments (Fairbanks winters, say) where in-car thermal management won't be sufficient to keep charging rates high. But those are the same environments where you can't even start a gasoline car without an engine block heater, and I don't see many "no cars in Alaska" arguments on the internet. Everything has limits, but I don't see this battery trickery having much of a home.
Gasoline powered engines work just fine in these temperatures, although many cars come with auto ignition systems that start up the engine periodically throughout the night to keep it warm. Otherwise you might have to warm it yourself in the morning using a gasoline powered "torch" (or whatever it's called), which sometimes ends up with the car going up in flames.
So it's honestly pretty funny to read that EV work "down to -10°C". Although probably relatively few of us are desperate enough to be living in such conditions.
And in places like Fairbanks where -40 (F/C) is fairly common in the winter, even cars that merely have an engine block heater will have trouble. You need even more heating pads for the rest of the stuff under the hood of you want to keep a car reliable and healthy in that kind of climate.
Now when you move just a bit off the sea, the continental climate kicks in, and you have weeks of -15 -- -20C.
On discharging lithium chemistries at those temperatures or "easily overcame with resistive" let me say that: you just don't know what you are talking about.
9.5 minutes from 0 to 100%.