Chemistry - Are there compounds more conductive than Silver (Ag)?

Solution 1:

Graphene supposedly has higher conductance.

The [...] resistivity of graphene sheets would be 10−6 Ω⋅cm. This is less than the resistivity of silver, the lowest otherwise known at room temperature.

but it is not a compound - it is a homonuclear molecule.

Solution 2:

The short answer is "no". There are materials, both actual and theoretical, which would have a higher conductivity, but not as a simple "material". They only make better conductors under very precise conditions. Since you specifically ruled out superconductive cooling I think we can also safely rule out materials that are a single atom thick as a prerequisite for great conductivity.

Graphene, for example, is known as a two dimensional or "2D" material. Its conductive properties only materialize when it is very, very thin. A single atom thick. You're not going to go out and buy a spool of graphene wire and expect it to be the best conductor ever.

Stanene is a relatively new discovery. So new, in fact, it hasn't even been produced or tested yet, though experiments are currently underway. It, also, is a 2D material made from a single layer of tin atoms. Tin is a "topological insulator", meaning that its interior structure isn't a great conductor, but its surface is a very good conductor. Electrons all flow on the outer surface. In electronics dealing with alternating current this is know as the "Skin Effect". So, theoretically, if it were a single atom thick it would be all surface and no interior, making it a better conductor than even graphene. Researchers are actually claiming 100% efficiency, a very bold claim.

So no, there are no "materials" which are better conductors, at least that I can find. There are, however, "atomic structures" which are better conductors. But since you're asking this question I assume you are not a microchip manufacturer, making these materials pretty much useless to you, personally. If you are a microchip manufacturer then, yeah, there's some exciting stuff out there. Otherwise, though, there is still nothing better than silver.