Like how we can simply fill up our cars with gas, why can’t we replace the discharged liquid anode/cathode with a precharged one at a gas station instead of spending 30+ minutes recharging a Lithium Ion battery?
Like how we can simply fill up our cars with gas, why can’t we replace the discharged liquid anode/cathode with a precharged one at a gas station instead of spending 30+ minutes recharging a Lithium Ion battery?
Comments
… you mean like a hydrogen fuel cell vehicle? Like the Toyota Mirai?
https://en.m.wikipedia.org/wiki/Fuel_cell_vehicle
Theres a startup doing this. For example https://www.jato.com/resources/news-and-insights/how-china-is-driving-battery-swapping-as-a-service-in-the-ev-market?hs_amp=true
Having a supply of spare batteries at every service station is a shitload of batteries. Unless you mean replacing the internal parts of a battery. Do you want fire? That’s how you get fire.
Flow batteries only have about 10% of the energy density of lithium ion batteries, so they’re just not really viable in their current state for automotive use
We have infrastructure to deliver electricity everywhere that everyone commonly drives cars. We do not have infrastructure capable of handling whatever chemicals flow batteries use.
Range is not a problem keeping the vast majority of people from using an electric vehicle. Most people have no need to be able to charge a car as fast as you can fuel a gasoline powered vehicle.
There is one company in China I think that does. You drive in like a car wash and it strips the battery out from underneath and slaps in a new one and you drive off.
Saw actual footage on YouTube IIRC.
A battery pack for a modern EV weights half a ton and replacing it requires basically dismantling and reassembling the whole car.
The most important part of energy storage for a vehicle is weight. If your battery is heavy, it doesn’t matter how fast it charges or whatever, because having to carry around the weight of the battery is too inefficient.
You need to maximise energy density for minimum weight.
[deleted]
That technology DOES exist. I don’t recall what the problem with it was, though.
Edit
https://cleantechnica.com/2023/12/31/new-flow-battery-electric-car-usa-ira/
Added complexity and much more expensive. You need to pay for the electricity as well as the distribution/transportation of the electrolyte. No way to charge your car at home or garages. And so on.
You are basically trading one improvement for 5 disadvantages over normal EV.
Tesla tried something similar in 2015, battery swapping, but it didn’t end up being viable and they canceled the whole thing. The way the industry seems to be heading today is better DC fast charging, with models like the Ioniq 6 charging 100 miles worth of range in 9 minutes
Generally flow batteries have a low energy density, which means you would get less range per ‘refuel’ than a lithium battery of the same size. So you can “refuel” your battery quickly, but you have to refuel it a lot more often. The systems I’m familiar with that don’t have this issue often have power density issues instead (i.e. you’re limited in how ‘quickly’ you can extract the energy out of the battery), but I don’t know how bad that is for vehicles.
The other problem is logistics. We already have an extensive grid setup to produce and distribute electricity. This makes a system to ‘refuel’ lithium batteries pretty easy to setup. Flow batteries would require an entirely new logistics system.
A combination of significantly lower energy density (and thus lower range) and lack of infrastructure. I want to say it’s like 1/10 that of lithium ion. You also can’t just put the electrolyte solution in existing fuel gas stations. They’re just not designed to handle the electorlyte solution.
There’s also likely a cost factor. Existing EV infrastructure is cheaper to build and electricity is cheaper than electrolytes.
They may be an option in the future, but the tech isn’t ready for widespread adoption yet when compared to other tech.
We already have the technology to recharge in between 5 to 10 minutes, and keep in mind that this is only needed on road trips. Literally 99.5% of driving in the United States is under 200 mi a day. So for all of those cases you leave in the morning with a full charge having spent zero time on it.
We use lithium batteries because the smartphone industry did most of the R&D needed to bring them to market,
Until suddenly, people realised hey we can power cars with this tech
There are many competing battery technology that have much higher theoretical energy density, but no one have eyet to spend the required capital to bring em to a usable state
TL:DR we use lithium because it’s what we have
There actually is a great technology that is very similar to a flow battery that works extremely well for cars. It isn’t considered a flow battery, but a fuel cell is effectively identical to a battery where the anode is hydrogen and the cathode is oxygen floating free in the atmosphere. Fuel cells can run on hydrogen, but they can also use hydrocarbons like butane, methanol, or even gasoline.
Fuel cells are less efficient than batteries, and it takes a lot of energy to turn electricity into hydrogen or methanol. Hydrogen requires either extreme pressure or extremely cold temprature to cram a reasonable amount of it into a tank. But the main disadvantage of fuel cells is that they are really hard to make without large amounts of platinum or platinum group metals. Those metals act as very efficient catalysts. There are other catalysts, but platinum group metals are extremely durable and reliable, other catalysts break down over time.
Despite those disadvantages, there are prototype aircraft that use fuel cells. Hydrogen is a very light anode, even with the sturdy fuel tank it requires, and the fact that the cathode is everywhere is a huge bonus.
As a side note to comeback to electric recharging:
There has been a couple of research to increase the recharge rate like hell.
We may see something at one point… Or not (the market is probably more interested in reducing price first, maybe even weight if possible)
At least one of the Chinese automakers has a battery swap model where you pull in and it swaps out your depleted lithium batter for a fully charged one.
There have been projects to design quick-replace batteries but there are insurmountable issues.
They weigh roughly one tonne.
It requires a completely standardised design for all batteries across all models, including where the connectors are in the car
It then slows down or inhibits design iteration and development
It doubles the amount of batteries required to be in circulation. This is extraordinarily expensive.
Most importantly, it relies on the garage you stop at having a load of batteries ready to go, this requiring logistics and planning for demand. This applies regardless of technology.
Water is really heavy, flow batteries have lots of water, vehicles need to be light
Flow batteries are better suited for grid level storage where you can have a building sized battery. You need three or four tanks for a flow battery two for the charged electrolytes, and one or two for the used electrolyte (depending on the fluid being used). The volumetric density of a flow battery is quite poor, but it can scale quite easily.
Flow batteries can come into their own when you have a building sized batteries dotted around, which can be easily done being they pose much less fire risk than lithium based batteries.
Picture a gas station, with gas pumps.
But instead of pumping gas, it pumps flesh-melting acid.
That is one of the major reasons why.
Look into a company called Gogoro. They have a network of battery chargers where you can hot-swap the battery to your electric moped without waiting to recharge, sort of like how you can swap propane tanks at grocery stores. Closest thing I can think of to what you’re talking about.
This is basically what TankTwo is, making smart small batteries that can be transported like liquids…
TankTwo
setting aside the energy density problem. many of the electrolytes you might want to use burn violently in the presence of air or water. even if you could pump it like gasoline, you really don’t want the general public handling something like that.