this post was submitted on 15 Sep 2023
214 points (85.0% liked)

Technology

59207 readers
3474 users here now

This is a most excellent place for technology news and articles.


Our Rules


  1. Follow the lemmy.world rules.
  2. Only tech related content.
  3. Be excellent to each another!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, to ask if your bot can be added please contact us.
  9. Check for duplicates before posting, duplicates may be removed

Approved Bots


founded 1 year ago
MODERATORS
 

Fully Charged in Just 6 Minutes – Groundbreaking Technique Could Revolutionize EV Charging::Typically, it takes around 10 hours to charge an electric vehicle. Even with fast-charging techniques, you're still looking at a minimum of 30 minutes – and that's if there's an open spot at a charging station. If electric vehicles could charge as swiftly as we refill traditional gas vehicles, it wo

top 50 comments
sorted by: hot top controversial new old
[–] [email protected] 55 points 1 year ago (43 children)

What a bullshit article. While better anode materials are always nice, these claims about charging speed are just dumb. That's only so much power you can push into a battery and today's 350 KW chargers are probably already the practical limit. And if you can't take a 20 minute break every 400 km or so, you should go home and rethink your life.

[–] [email protected] 7 points 1 year ago

I was thinking that this is one of those thousands of battery technologies we will never hear about again.

[–] [email protected] 3 points 1 year ago* (last edited 1 year ago)

yea, charging speed probably capped by anode chemistry. would splitting the pack by multiple BMS's help circumvent this? if the charging time is the limit, people who prefer to drive 800km at a time could use an extra battery pack. that way a 20 min could be justified for them lol also we all know that it wont be 400km per charge. it would be only 330km at best.

load more comments (41 replies)
[–] [email protected] 43 points 1 year ago* (last edited 1 year ago) (7 children)

Alright, so let's assume a 100kWh battery like some tesla models. Now, someone made such a battery that can be charged in 6 minutes... how much power does it need?

100 kW•h / 6minutes = 100kW•h / 0.1h = 1000kW = 1MW

So, we need 1 MEGAWATT car chargers ... that's some power required there.

[–] [email protected] 26 points 1 year ago (4 children)

Possibly even more significant, those are some large cables and even larger contacts required. There's no way a 1MW disconnect is just a little plug you stick into your car.

In fact as an electrician I can't think of anything even near megawatt class that would be connected with a portable cord, or at a voltage that would be safe for consumers to handle.

Maybe someone in the mining industry or similar can chime in, but I currently run a pumping station that includes 3000HP motors (2.2MW). These are 4kV 3 phase units where each phase cable is as thick as your arm. All connections are bolted and taped to avoid corona discharge. Just dragging the cable to the car would be more than the average driver could handle.

I don't see a way to get these power levels into a car short of a standardized and semi-automated docking system. Or maybe go back to the idea of standard swappable batteries where the battery then is charged rapidly for the next customer.

[–] [email protected] 16 points 1 year ago* (last edited 1 year ago)

The power lines in the cable are disconnected inside the charger by a contactor until communication with the car is confirmed established with a handshake, and then it connects power to the cable. If the communication with the car drops at any point, the contactor disconnects the power to the cable. It requires both effort and knowledge to bypass this design, it basically can't happen accidentally.

Also, the cables you mention are that large, because they're passively cooled, DC car chargers have watercooled cables so they can be much thinner without overheating. And at 4kV you're looking at significantly different insulation thickness as well, compared to the 400-800V that electric cars use.

[–] [email protected] 8 points 1 year ago* (last edited 1 year ago)

Electric busses already have automated docking systems, the only problem I see is cost

https://assets.foleon.com/eu-central-1/de-uploads-7e3kk3/39195/17_syb21_content1.79205c469709.jpg

[–] [email protected] 2 points 1 year ago (3 children)

That's 4,350 amps @230vac. The service fuse for my entire home is 80 or 100amp (single phase domestic dwelling Australia). The main breaker is 63amp.

[–] [email protected] 3 points 1 year ago (2 children)

DC fast charging typically runs at 400 volts, with some cars doing 800. They also do it with highly specialized equipment and service lines you'd never see in a residential setting.

When charging at home, you have all night. A 50A circuit will go 0-100 on most cars in that time, and if you look at what most people actually drive you can generally get by on much less.

load more comments (2 replies)
[–] [email protected] 3 points 1 year ago

Fast charging uses up to 1000 V DC, and the current limits of conductors are typically set by the temperature it reaches when conduction losses heat them up. This can be (and is) offset by liquid cooling, allowing current installations to deliver up to 650 A (Tesla supercharger v3).

With improvements, it's not far off 1 MW.

[–] [email protected] 2 points 1 year ago

yea, fast charging is usually achieved using DC.

load more comments (1 replies)
[–] [email protected] 13 points 1 year ago (3 children)

thats assuming 100% efficiency. which is impossible

[–] [email protected] 4 points 1 year ago

I'm happy with 69 efficiency. 🙃

[–] [email protected] 3 points 1 year ago

True, so I guess 1MW won't even be enough

load more comments (1 replies)
[–] [email protected] 2 points 1 year ago (13 children)

most EV cars are more like 60kwh though.

load more comments (13 replies)
load more comments (4 replies)
[–] [email protected] 32 points 1 year ago (5 children)

I'm sick of reading phones and cars charging in a matter of minutes for the past decade.

[–] [email protected] 12 points 1 year ago (4 children)

Don't worry about it too much. These sorts of articles focus on battery tech, but the ultimate limiting factor is the ability of the plug to supply power.

A Tesla Model 3 has a 75kwh battery. Let's say it's at 20% charge. That's 60kwh to get it full (assuming 100% charge efficiency). It would take 600kw to charge that in 6 minutes.

The SAE J1772 plug is only rated to go up to 400kw on DC level 2, and you'd be hard pressed to find a charger that does it. I couldn't find info on Tesla's plug, but since it's about the same size, it's likely around the same. Tesla's superchargers are themselves only going up to 250kw.

It would take yet another plug standard, and chargers that can actually handle such a load. Oh, and upgrading the electrical network to handle such a beast in widespread use.

Most of which is pointless, anyway. EVs are best handled by giving them a little charge wherever they're parked. For road trips, unless you're the type to pee in a bottle and eat sandwiches you prepared ahead of time, about 300mi range with existing charge rates is sufficient.

load more comments (4 replies)
[–] [email protected] 9 points 1 year ago (2 children)

I recently got a phone that charges at 65W, from empty to full in 30 minutes. It's at least getting better all the time, I'd say

load more comments (2 replies)
[–] [email protected] 9 points 1 year ago* (last edited 1 year ago)

It's a matter of power delivery at the moment. A modern rapid charger you can add about 10 miles a minute so 10 minutes is normally fine.. barely enough time to have a cup of tea.

Getting power to a battery faster starts to become impractical simply because of the thickness of cable you'd need to do it, and the internal heat the battery would generate if you threw power at it that fast.

Think of it like a swimming pool. You can fill it with a small hose, might take an hour or two.. bigger hose, maybe down to 30 minutes.. you want it to be done in seconds? Sure.. let me just turn up with this dump truck full of water...

Most of the things you read are about as useful as potato batteries. 'We've come up with this new compound that can take charge really fast'. Sure. Now make millions of them, the size of a car, for a price people will pay. Oh you can't... there's the rub.

Turns out there are a near infinite ways of combining materials that make a battery, and only a handful that scale to industrial production.

load more comments (2 replies)
[–] [email protected] 24 points 1 year ago

Oh look. Another "could revolutionize" article.

[–] [email protected] 24 points 1 year ago
[–] [email protected] 14 points 1 year ago (1 children)

And like all battery advancements we will maybe get this in the next ten years.

[–] [email protected] 14 points 1 year ago* (last edited 1 year ago)

If at all. A lot of published science turns out not to be usable in real products, if not completely wrong. For starters, someone else should replicate the findings independently, to confirm them, then the manufacturing process needs to be scaled and the cost reduced, then ... someone will need to figure out how many MW this thing needs to charge in 6 minutes ...

[–] [email protected] 8 points 1 year ago (1 children)

No revolution is coming. Deal with it. But it's also okay to have up to hour charges. Take a break, get some coffee and everything is fine. If you can sit 3h in traffic to work every day or sleep in front of the store on black friday so you can get 20% off on things you don't need, you can sit every once in a while on long journeys. You need a break from driving anyway.

load more comments (1 replies)
[–] [email protected] 8 points 1 year ago (3 children)

All of these speedy innovations are great and everything, but they are impractical for most people. They will be useful for emergency situations and for long trips, but for the large majority of people driving electric vehicles their slow chargers in their houses will work just fine.

I love hearing about new ideas, but it's annoying hearing them phrased like it'll change the entire charging game. It doesn't matter if they invent things that charge cars in 30 minutes. Most people will still be slow charging their car while they sleep.

[–] [email protected] 13 points 1 year ago* (last edited 1 year ago)

The barrier to adoption is so often outlier scenarios though.

A vehicle is a huge purchase. For many it's the largest purchase they will make. For everyone else it's the second largest, behind their home. They want to make sure it does everything they do normally, and everything they might do once in a while.

As a small example, my family travels to a specific lake about once per year, for around a week. We switched cell phone providers to one that worked better at that lake. It costs a bit more, but even though on an average week it doesn't matter at all if our phones work at that lake because on average we aren't there, it was important to have our carrier work there. The outlier scenario actually made the decision for us with all other factors equal.

It doesn't matter if the average buyer isn't likely to take longer trips frequently. What does matter is that those outlier scenarios can be conceivably accomplished without significant hassle. And before you say that's not reasonable, consider that it doesn't matter that it isn't reasonable.

People base their purchase decisions on unreasonable factors all the time. How else do we explain how many trucks are on the road?

It does not matter that current charging methods cover 99% of scenarios for 99% of people. The glare of that 1% will shine a light brighter than the positives from the standpoint of widespread adoption. And from that perspective, news of a solution to slower charging is a very good thing.

[–] [email protected] 7 points 1 year ago (1 children)

Also slow chargers in houses will not work for many people. The majority of ICE drivers that won't even consider an EV as an option yet live in apartment buildings which currently don't have electric charging and likely won't install them anytime soon, or live in areas without access to a driveway/garage (i.e. basement suites)

load more comments (1 replies)
load more comments (1 replies)
[–] [email protected] 7 points 1 year ago (1 children)

No it won't. It's bullshit.

I've seen these articles literally for the past 3 decades now. It's all clickbait, it's bullshit and will. Not. Happen.

load more comments (1 replies)
[–] [email protected] 6 points 1 year ago

Eh, 15 minutes of charge every 3 hours of driving is fine for me. Long distance is not a problem with the Tesla network. And it's opening up for everyone else too soon. Hopefully it will cause competition for the other networks and force them to improve.

[–] [email protected] 5 points 1 year ago

https://onlinelibrary.wiley.com/doi/10.1002/adfm.202300143

Abstract

Mixed transition metal oxides are promising anodes to meet high-performance energy storage materials; however, their widespread uses are restrained owing to limited theoretical capacity, restricted synthesis methods and templates, low conductivity, and extreme volume expansion. Here, Mn3-xFexO4 nanosheets with interconnected conductive networks are synthesized via a novel self-hybridization approach of a facile, galvanic replacement-derived, tetraethyl orthosilicate-assisted hydrothermal process. An exceptionally high reversible capacity of 1492.9 mAh g−1 at 0.1 A g−1 is achieved by producing Li-rich phase through combined synergistic effects of amorphous phases with interface modification design for fully utilizing highly spin-polarized surface capacitance. Furthermore, it is demonstrated that large surface area can effectively facilitate Li-ion kinetics, and the formation of interconnected conductive networks improves the electrical conductivity and structural stability by alleviating volume expansion. This leads to a high rate capability of 412.3 mAh g−1 even at an extremely high current density of 10 A g−1 and stable cyclic stability with a capacity up to 921.9 mAh g−1 at 2 A g−1 after 500 cycles. This study can help to overcome theoretically limited electrochemical properties of conventional metal oxide materials, providing a new insight into the rational design with surface alteration to boost Li-ion storage capacity.

[–] [email protected] 3 points 1 year ago (4 children)

Imo the way things stand things are already good enough as they are.

we don't need to double battery capacity/distance or even charging speeds, it's a massive waste of resources that won't benefit the vast majority of people.

from quick google

Every day, there are some 70 Million (M) worldwide driving trips. The average trip duration globally is 15 minutes long. The average trip distance globally is 15 Kilometers / 9.3 miles. The average speed globally is 30 km/h (or) 18.6 mph

so even if you have a 200km worst case scenario range on your EV, unless you are one of those people that are on the road a lot, it literally covers like 99% of your car usage.

Hyundai EVs charge with 350Kw, to 80% in like 15m which is perfectly fine for a longer roadtrip imo. I used to travel 200kms every two weeks and in most cases I took a rest half way through the 2 hour trip anyway to stretch.

if you are one of those guys that will come on and say you drive 500+kms every day and BEV is just unacceptable for you, well guess what, just get a fucking Hydrogen EV, pretty sure those can get up to 1000km ranges already which is more than my Diesel Hyundai.

[–] [email protected] 10 points 1 year ago (1 children)

Faster charging means a lower chance of all the chargers are in use at the service stations en-route. Currently if you're in need of a charge you'll have to wait for the others cars to get charged and then you still have the 20+ minute wait for your own car. That's going to put a lot of folks off owning an EV. Coupled with the fact the EV uptake is growing a lot faster than the charging infrastructure to support it. Faster charging has a lot of benefits.

[–] [email protected] 3 points 1 year ago* (last edited 1 year ago) (2 children)

except, the vast majority of your trips are from your home to some place and back, you charge at home and the range is more than enough to cover 90+% of your trips.

rather than focusing on super chargers (which we also need along high ways) we need to focus on smaller lvl 2 chargers at places where they make sense, apartment complexes, offices, to enable BEV use for people who don't own a home with their own garage.

you also completely ignore load balancing of the infrastructure, for one 350KW charger you can create 7 50KW chargers, that means 7 cars being charged while parked at places you spend lots of time at instead of 1 charger charging 1 car.

so like I said, fast chargers make sense next to main roads and highways during long trips and they don't make much sense at all in cities.

load more comments (2 replies)
[–] [email protected] 9 points 1 year ago (1 children)

Average trip duration is not a great metric because they measure a trip as going from point A to point B. That's great, but then I do six trips a day in errands.

Total miles per day is the metric to use. On average, in America, it's 37 miles.

That is to say, EV cars would work for many people. But to reach the majority we need these advancements.

[–] [email protected] 3 points 1 year ago (2 children)

why? you literally say 37 miles, that means it's already good enough for the majority.

load more comments (2 replies)
[–] [email protected] 5 points 1 year ago (1 children)

I still don't understand why people need ultra distance in EVs. If I drove as much as often as the "I need a million mile range" crew I'd take a good, long look at my life and what was wrong with it.

[–] [email protected] 3 points 1 year ago (3 children)

I mean, it could be part of the job they do, whatever, but people vastly overestimate what they actually need from a vehicle.

load more comments (3 replies)
[–] [email protected] 4 points 1 year ago (13 children)

Averages are useless. It does not matter if my car is fine most of the time, I'm not going to have a second car for when it is difficult or impossible.

Hydrogen is the other tech which makes quick refuelling possible, but there are not yet enough hydrogen refuelling stations to make them feasible for most drivers. And we don't yet know if leaks can be controlled enough to make hydrogen a net positive for consumer applications.

load more comments (13 replies)
[–] [email protected] 3 points 1 year ago* (last edited 1 year ago)

I asked gpt4 to explain this abstract in terms a high schooler would understand.

Sure, this text is talking about making better batteries. Right now, a type of material called “mixed transition metal oxides” has potential to be a really good component in batteries. But there are problems like they don’t hold as much energy as we’d like, they’re hard to make, and they don’t conduct electricity well.

So, the researchers made a new version of these materials, tweaking them with manganese and iron. They used a new, easier method to make super-thin sheets of this stuff. This new material can hold a lot of energy, way more than the old versions.

The thin sheets also let electric charges move more easily, which is good for battery performance. Plus, they made sure that the material doesn’t expand too much, which helps keep the battery stable over time.

So basically, they made a high-performance battery material that can be charged quickly, holds a lot of energy, and lasts a long time. It’s like creating a new recipe for a better, longer-lasting smartphone battery.

load more comments
view more: next ›