Can flow batteries finally beat lithium?
spectrum.ieee.org
spectrum.ieee.org
When you do sub-2h trips on a Tesla, you don't need to fuel at all. The car charges at home, you spend no time whatsoever on the act of fueling. On longer trips spanning 3+ hours, when you plug a Tesla, you might be charging for 15-20min but the attention budget you dedicate to the act is on the order of 20s. You stop, plug the car, walk away and go eat a taco or buy some groceries or empty your bladder, or watch a video in the car. You'll physically arrive maybe 10-15min later than a gas/flow car (assuming no resting), but you'll have mentally dedicated much less time to the act of replenishing the spent energy.
To me, this is more than worth it. Over a year of driving and commuting and road tripping, I spent a tiny fraction of what I would have on the act of starring at or thinking about an energy replenishment device.
The idea of frequently babysitting the refilling of a liquid in my car is obnoxious.
5 mins is like 50 gallons of gas, which is a very, very large gas tank. That's like larger than a Ford F-350 gas tank.
My car's gas tank fills in like one minute, if I run it fairly close to empty (which is rare)
Assuming we’re just talking about driving around for errands and not things you use a truck for, this would still be impressive.
Family and I used it for moving across state, and with no load (or very light load, no trailer) and a full tank it could make a 700 mile journey in one go with fuel to spare. That included going up a couple mountain passes.
Fully loaded (20ft enclosed trailer and truck bed), it still made about 500 miles of the way before we needed to refuel.
Worth noting, we found the mileage wasn't actually affected in any significant way by any cargo we hauled. It was pulling that trailer, regardless empty or loaded, that reduced mileage (aerodynamic drag!).
Street driving is less efficient than freeway driving, obviously, but with a ~40 gallon fuel tank it should still make stopping at the pump a very infrequent event.
In any case, it's a redundant point because it's unlikely a battery fluid system would be designed in the same way as old fashioned gas pumps. More likely, it would clamp on and you can sit in the car or take a small walk while it does it's work. Gas pumps are designed to be handheld because they are fast. If it took 5 minutes to pump gas, we would probably have redesigned these by now too.
Pull up, insert card, insert filling handle, start, lock on, step to the side to avoid fumes, when it clicks off you put up handle, put gas cap on, drive away.
Electric cars have a lot of pluses, but refilling the tank as quickly as gasoline or diesel isn't one of them. I can drive at highway speeds for over thirteen hours on two refills of the tank, each of which takes less time than walking in and using the restroom.
Are you saying that the charging stations between the two aren’t being used, and at more than 20 minutes at a time?
But I guess the long time that electric charging takes is usefull. You can spend it on mental gymnastics that being forced to stop more often and for longer is somehow better.
Where in the world is that still a thing?
Oregon just this year finally changed its state-wide mandate that all pumps at a station be Full Service to half Full Service and half Self Serve. Yes, it's mandatory for stations to have Full Service pumps in Oregon.
Further reading:
https://www.oregon.gov/osfm/pages/self-serve-fueling.aspx
https://www.oregonlive.com/commuting/2023/08/self-serve-gaso...
https://oregoncapitalchronicle.com/2023/03/20/house-passes-b...
Outside of that, there's a full-service station down the street from me, but it's about 30 cents per gallon more to get full service (though it is full service and they will check your oil, tire pressure, coolant, windshield washer fluid, etc., and refill the washer fluid and air up tires). It's the only one I know of at all outside of those two states (though of course there must be others still out there).
> Oregon has removed that.
So maybe some people need forced breaks, but I don't, I can decide myself where I want to do my break and it is not at a gas station, with gas station food, has station atmosphere and gas station prices.
If you want to fill up all the way, there is a little switch which locks the pistol so you don't have to hold it and it will shut off automatically. It's that easy.
Also worth remembering that time is spent inhaling carcinogenic fumes.
I try hard to stand away from the pump, and will jam my gas cap in the handle if it doesn't have the ability to lock it on.
That's not even farfetched if your car runs on methane.
Yup. Roadtrips are rare in my life, and worth the wait. Gassing sessions out of my weekly experience? Life change. I do miss the squeegies though.
98% of EV charging happens this way. Trying to emulate traditional fuel stations is actually chasing a 2% use case... Like trying to out-perform cloud storage with a better jazz drive it's just an anachronistically bad interpretation of the fundamental problem.
this suggests that some crucial aspects of the situation have escaped your notice, so perhaps your dismissal is too hasty
As the article points out, conventional batteries are a logistical nightmare on a battlefield.
So trying to emulate traditional fueling procedures isn't just pure anachronism, it is about not having to wait for ages on a charging station in the middle of nowhere to get another go at maximum range.
Eventually, the local authority or landlord may install charging on every parking slot, but until then lots of people don't want to deal with the anxiety of not knowing if they can charge today.
It will be a bit lower due to higher use of public transport and lower average income. But it represents a large fraction of car ownership (about 30% of total cars; not sure about new)
98% of EV charging probably happens that way now because only 1.2% of cars in the US are EVs. Most people who cannot charge at home avoid EVs. Do you think it will remain a 2% use case when EVs are the majority of cars?
If you find yourself stranded on the side of the road, you simply drain some depleted fluid into a red gas can, hike down the road to the nearest station and exchange it for a gallon of energized fluid.
All the benefits of conventional EVs without the downsides.
Where this could be a major use case is large scale grid batteries. That would allow for an effective baseline power store for solar and wind power.
I don’t know about the other practical considerations of putting this into a car, but certainly the article suggests the density problem to be solved
> With the basic science problem resolved, Katsoudas adds, Influit is now developing a battery with an energy density rated at 550 to 850 watt-hours per kilogram or higher, as compared to 200 to 350 Wh/kg for a standard EV lithium-ion battery. The company expects larger versions would also beat old-style flow batteries at backing up the grid because the nanoelectrofuel can be reused at least as many times as a flow battery—10,000 or more cycles—and it will probably be cheaper.
If a 5kW unit would be prohibitively expensive or large for my example scenario, then different materials and configuration for the ion exchange unit would be needed.
Note: I am not worried about the size of the pumps and tanks. These could be stored underground, in the case of a suburban house. For apartments, this would be harder to retrofit. Above paragraphs in this comment are all about the ion exchange unit, which would determine the maximum charge/discharge rate.
But granted 5kW is not a big problem.
I've suggested before that some site such as Electrek have a monthly column, "1, 5 and 10 years ago in battery announcements", so we can look back at the hype. There are so many of these "sort of maybe works in the lab, trillion dollar industry next year" announcements. Usually with videos full of stock photos and talking heads.
You can imagine that there is appeal to being able to store energy year-round, not having to deal with price regulation and energy companies.
My point is, a situation can arise where people want nothing to do with the grid unless there is no other way. Back in the day, running a steam turbine with coal in your backyard was not practical. So was dedicating an entire room for a mainframe computer. When things get miniaturized, running them in your home becomes possible.
If these flow cells, which have been around for a very long time, would somehow be practical in a scaled down form, I can see it work in a one-per-building configuration, assuming those buildings have solar panels.
However it may be preferred to either run the flow cells on a centralized grid as you suggest, or to provide it a more local level, e.g. one installation per residential block. Because people in apartments also need power.
Sure there are cases where EVs are an ill-fit. For example, if you are an apartment dweller and do not have a way to charge the car at home. But many other concerns are way overblown.
The energy is in liquid form... you just drain the used liquid, fill it up with "charged" liquid, and you're back on the road.
The "dead" liquid is "recharged", but that happens in tanks at the fueling station. The car doesn't have to sit there and wait.
On paper, it would be more like filling up and emptying 4 gasoline-powered cars. That's about 8x the process in the ideal case.
Other considerations would be the necessity for 8x as much storage in gas stations, 8x as many refilling trucks to supply and empty those stations, and above all, the development of a nationwide network of such infrastructure as pervasive as the existing fuel network.
This is even more dead on arrival than hydrogen.
That they don't remotely approach maximum practical flow rate that can be produced by a pump, even a small one?
That there are quick connectors that can vastly exceed the flow rate of the current hand-held nozzle shoved into a hole?
Standard Model 3 has 272 miles of range. That 4.5 hours of driving, which is way more than most people are doing in a day. I drive 30k miles (~3x the average) a year but average about 80 miles a day.
Unless you are driving across the country frequently this isn't really going to make any sense. Then on top of that you are going to have to support totally different battery tech, then also the density of these batteries isn't great.
This is just never gonna happen.
In the US driving isn't really a time waster compared to public trans because pub trans is usually slow, doesn't take you to your destination so you gotta walk, doesn't come frequently and you put yourself in more physical danger. Hard to read when there is a guy tweaking next to you.
The costs of doing this plan mean that it will absolutely never happen. The grid is there, super chargers are easy to use, no fluid storage or machines to manage fluids. No fluid leaks, no extra infra.
Plus battery tech and ability to recharge is always changing.
You can sometimes combine it with a shopping spree or something but if you don't happen to need to do that (which for me is most of the time) you're stuck waiting.
I mean when I still had a car I used to hate going out just for a tank run (like before a night trip to the airport) and the station was within half a mile. I couldn't do that every few days plus have to wait around for that thing to charge. My car was to make my life easier, not harder (and even then it failed at that because I hate driving so much). Glad I live in a city now with amazing public transport.
Isn’t this true of the discharged electrolyte in conventional batteries?
The better solution is presumably to charge the used fluid directly at the fueling station using a grid connection, though that does have some issues. What happens if the used fluid out of some random car is contaminated with something?
Ideal for solar plants, etc.
What advantages does flow provide over non-flow chemistries in stationary contexts? Do you mean remote and stationary, thereby benefiting from refuelling?
Unlike in conventional batteries, you can design a battery with any combination of stored energy and of maximum power.
The stored energy is determined by the volume of fluid stored in a tank, while the maximum power is determined by the surface of the electrodes.
For large amounts of stored energy, a flow battery becomes much cheaper than a conventional battery, where you must increase simultaneously the energy and the power, by making bigger electrodes (or by increasing the number of electrodes, i.e. the number of batteries).
Moreover, because the active substance stays fluid instead of changing phases, it is not degraded after each charge-recharge cycle, so the lifetime of a flow battery may be much greater. There may still be problems with precipitates or changes in chemical composition in old working fluids, but such problems should be easier to solve than making long-lived solid electrodes.
If the medium would be cheap and could be pumped into arbitrarily large tanks that don’t need constant energy input to hold the charge then this could be an enabler for seasonal storage.
I don’t know whether either of them are true for flow battery (yet).
They are certainly not true for H2. H2 also has atrocious round trip efficiency, not sure about flow either.
This is actually plausible, because there are fewer parts. Each li-ion battery consists of a huge number of cells which must each be manufactured with precision, whereas precision parts comprise only a small piece of a flow battery - most of it is just the four tanks
This does seem a relatively promising tech. Cheaper and less flammable. One thing that don't mention is whether it's can charge conventionally as quickly as li-ion. If so then it could be a drop in replacement even without deploying electrolyte replacement stations.
> Influit expects that its current generation of nanoelectrofuel, together with the entire ecosystem needed to produce, distribute, and recycle the fuel that the company is building around it, should cost $130/kWh when used in an EV. In comparison, lithium-ion batteries cost around $138/kWh.
No details given of how they arrived at this figure. If it sounds too good to be true then it probably is.