Electric cars are creating additional sources of funding for battery research, improvement of the electrical grid (there was a movement to get rid of central power generating and just use generators at each house), and electric generation smoothing.
The kinds of battery used in cars and the kinds of batteries suitable for grid-scale operation only have a small overlap. They have entirely different needs. Car batteries make lots of trade-offs to very lightweight for example which is totally irrelevant in a stationary facility.
I think the only reason Li-ION batteries were even considered for grid-scale is that better suited battery technologies simply haven’t been researched until very recently.
If our goal was energy storage for our grids, we would not be researching BEV battery tech.