Vapor deposition techniques were utilized to synthesize very thick (similar to 1 mm) Li-ion battery anodes consisting of vertically aligned carbon nanotubes coated with silicon and carbon. The produced anode demonstrated ultrahigh thermal (>400 W.m(-1).K(-1)) and high electrical (>20 S.m(-1)) conductivities, high cycle stability, and high average capacity (>3000 mAh.g(Si)(-1)). The processes utilized allow for the conformal deposition of other materials, thus making it a promising architecture for the development of Li-ion anodes and cathodes with greatly enhanced electrical and thermal conductivities.