The Model 3 actually uses aluminum cabling in some places (I think the main cable between the battery and the motor/controller assembly). In certain application

The Model 3 actually uses aluminum cabling in some places (I think the main cable between the battery and the motor/controller assembly). In certain applications where weight is at a greater premium than volume, it can actually be superior to copper as its resistivity divided by density is lower than copper. (BTW, lithium is even slightly better on that metric than aluminum, although it oxidizes extremely rapidly so has to be carefully protected, making it impractical). Extremely long-term, sufficiently high quality graphene or carbon nanotubes can theoretically have higher mass-specific resistivity than copper or even aluminum. But in practice, CNTs and graphene have much worse electrical conductivity due to defects and the need to conduct between tubes/crystal regions/bundles.