A. The new carbon-carbon material belongs to simple substance, so A is wrong;

B. The new carbon-carbon material is a simple substance and does not belong to non-electrolyte, so B is wrong;

C. High-temperature-resistant and long-life antioxidant ceramics cannot conduct electricity, so C is wrong;

D. New carbon-carbon materials and ceramics have high hardness and good wear resistance, so D is correct.

So choose D.