Better batteries, yeah. That’s down the line. We will also generate heat during the actual use of any devices. But, less.
It also could become the most efficient commercial batteries, but I expect the cost will be prohibitive. Sending electricity always has a loss, but it doesn’t through a superconductor, so these will have a lot of uses at power generation sites, both reducing heat and losslessly storing it (until it enters the traditional grid).
It won’t directly transfer to faster tech or anything like that, but it helping quantum computing could do so indirectly.
Definitely it’s more of a facilitating research kinda thing. You can’t play with superconductors in a lab in a cost efficient way, but this could let you.
Also maglevs and MRI’s directly use superconductors currently, so that’s a direct use, lower cost MRI’s and incredibly fast trains.