Considering that most "EV batteries" are actually just smaller batteries glued together to bigger cells, modules and packs, I don't think this is as much of a win as people think it is.
It's like saying "We can green the planet with Duracells." Ignoring what's in the batteries or what it takes to manufacture them. Or how they degrade over time.
We may need to look at hybrid battery solutions with alternative energy storage systems, like graphene supercapacitors.
It's not as black and white. EV batteries are getting produced and will get produced quite a lot it seems. We'll be using them for transportation, but if we can also use them for short-term grid storage, that certainly improves the sustainability math. Using things better is a win, so let's do it.
We can't green the planet with Duracells, but it's certainly better than producing and not fully using the Duracells.
Supercapacitors aren't that useful for grid storage. The energy density is very low. They have a very high power density which allows them to produce or store enormous amounts of energy in a short time, but that's not really a problem that needs to be solved if you're already using some sort of lithium ion battery which already have a power density that's way beyond what you'd need in that application.
Cylindrical cells are fine as long as they can be made cheaply and the costs (economic and environmental) can be amortized over a long life.
We'll probably start seeing more LFP batteries in coming years, which are more ideal for grid storage. (They're cheap and have a long life.)
Battery recycling needs to improve, but we'll probably get there eventually. Right now the volume of batteries that need to be recycled is just not very big. The Nissan Leaf, for instance, was only just released in 2010. Most of the EVs that have ever been manufactured are only a few years old.
"may need to" -Power Utilities worldwide have been looking at flow battery models for decades. What they lacked was supply chain committed to the longterm specific model, and a pricepoint which matched their needs. Lithium batteries were being made in volumes with a supply chain for multiple uses: cars, home storage, this industrial-scale purpose. It provided a pricepoint and a supply chain and logistics to match for BMS and demand management at scale.
Flow batteries are good. They exist. They didn't get the capital required to drive them to ubiquity, in industrial scale deployment .. yet.
Also, putting to one side "duracell" typically means a non rechargable, we actually can green the planet WITH canister sized individual battery instances ganged up into bigger units, because that's precisely what we are doing. The mistake is thinking batteries can do it alone. Not what format they come in and how we aggregate them. There are gigawatts and gigawatt-hours of Tesla batteries in deployment which provide frequency stability, and other load demand management services, and extend the duration that solar and wind power can be supplied without "firming" from Gas or other peaker plants, and they supplant traditional condenser spinning loads, and actually DO supply power. They have helped significantly alter the trajectory of change here.
This is a bit like saying "great: we can't build skyscrapers out of something as small as gravel, this is stupid: we invented bricks for a reason" ignoring the structural role of gravel as aggregate in concrete.
Individual cell technology is not the limiting factor here.
It's like saying "We can green the planet with Duracells." Ignoring what's in the batteries or what it takes to manufacture them. Or how they degrade over time.
We may need to look at hybrid battery solutions with alternative energy storage systems, like graphene supercapacitors.
https://www.laserax.com/blog/ev-battery-cell-types