You don’t need lithium. That’s just the story told to have an argument why renewables are allegedly bad for the environment.

Lithium is fine for handhelds or cars (everywhere where you need the maximum energy density). Grid level storage however doesn’t care if the building you house the batteries weight 15% more. On the contrary there are a lot of other battery materials better suited because lithium batteries also come with a lot of drawback (heat and quicker degradation being the main ones here).