I don't think lithium is 4x the price of aluminum. In January 2025, the North America price of lithium carbonate was $9.37/kg. But lithium carbonate is just 1

I don't think lithium is 4x the price of aluminum. In January 2025, the North America price of lithium carbonate was $9.37/kg. But lithium carbonate is just 18.7% lithium, so the price is $50/kg of contained lithium. In comparison, the current market price of aluminum metal is $2.62/kg. And aluminum compounds (where the large energy expenditure needed to reduce Al(+3) to the metal is not needed) should be cheaper. Aluminum is much more common than lithium. It's the third most abundant element in the Earth's continental crust after oxygen and silicon.