Lithium can be substituted to a fair extent. Nickel for EV...

Lithium can be substituted to a fair extent. Nickel for EV batteries provides more energy density but supposedly at a higher price. Yet, when lithium prices spiked last year that cost advantage actually inverted for a while. I don't know/follow the metals markets enough to know where things stand there.

Copper has less substitutes, especially for motor windings. Silver and aluminium can be substituted in some applications but silver is far more expensive and aluminium is a poor substitute because it is less conductive, subject to corrosion, etc. The only use case for aluminium economically substituting for copper that I am aware of is high voltage transmission lines.