Storage batteries are now LiFePO4. Lithium, Iron and Phosphate are all incredibly common worldwide. The latter 2 are already being mined in massive quantities for other uses, batteries would not use a noticeable portion of that output.
Battery minerals are not an issue, as you say. I'm still worried about the electrolytes and stuff - not in scarcity, but eventual pollution. They don't typically advertise them and I have a hunch they are nasty stuff.