Why not make the charging cables from aluminum wire?
Prominently labeled.
In several languages.
And hope potential thieves can read.
Aluminum is a lousy conductor.
Plus they will steal the aluminum also...the metal is at very high prices nowadays.
Your idea is the only thing that makes sense. Would need larger gauge wire to carry equivalent loads, but compared to copper, aluminum is cheap. having the charging station display the fact and those that can read will get the idea. The size & weight of the cabling should be a deterrent all in itself.
Use hemp wires.
Copper transfers electricity far more efficiently than aluminum.
The charging cables would be nearly double in diameter, making it awkward to handle.
Aluminum does have minimal scrap value, making it a target as well.