There's a lot of R&D being done for other energy storage technologies and chemistries. If Lithium becomes more expensive, those technologies will inevitably become commercially viable, and some are already expected to in the next few years. In fact, for large-scale longer-duration energy storage systems, there's a promising company called Energy Vault that has an unusual but fairly simple and practical system of stacking and unstacking cement bricks. It's basically the same concept as a pumped hydro system but with bricks instead of water.
I get that, but I'm also a skeptic. As mentioned, I'm in data storage. NAND flash is
*not* a perfect storage media. Pretty much ever since I've been in storage [over a decade], I've been hearing about all the technologies that are "just around the corner" that will displace NAND... Memristors, spin torque memory, phase change memory, etc... All of these have properties that would not only make them better than NAND, but cheaper... Or so their proponents state. Yet none of them are out of the laboratory.
The problem is that commercial viability is a hard thing.
I'd state that at the current state of the tech, lithium batteries are marginally commercially viable for automotive applications. If you want enough in a car to have decent range and performance (Tesla), it's incredibly heavy and expensive. If you skimp on the batteries to reduce cost, you end up with a poor-performing econobox with limited range and still costs $30K (Leaf). Right now the future of electric cars relies on storage chemistry
reducing costs to become competitive with ICEV. Because right now, a large part of the value proposition for BEV relative to ICEV includes subsidies, tax credits, etc to artificially reduce the costs.
So if lithium batteries get MORE expensive, well then those other storage technologies may become commercially viable
relative to lithium BEVs, but will still remain a small niche market relative to ICEVs, which is the dominant incumbent for transport.
Which isn't to say that I don't think there's anything better than Lithium out there. But they all need to continue innovation and cost reduction if any of them are going to overtake ICEV. I think it's going to happen, especially as oil becomes harder [and more expensive] to extract, but I've seen too many people wave their hands and say "well the alternatives will become commercially viable because of R&D spending" when it's usually a LOT harder than it looks.