it sounded like they were trying to say battery grid storage is going to be the main problem:

After the introduction of smartphones, wind turbines, and high-capacity batteries, copper’s role has grown from important to indispensable.

Building a grid that stores energy in large-scale battery packs sends the tally soaring to 3 billion metric tons.

Except the article they linked is about lithium-CO2 batteries and does not mention copper at all.

And even if we really do need to reduce grid storage to save copper, we can do that with more baseline nuclear power, no need to keep involving fossil fuels.