Graphite foam is promising material.

James Klett a materials researcher Oak Ridge National Laboratory (ORNL), Oak Ridge, Tenn discovered a carbon-based foam material that is three to nine times more thermally conductive than typical lightweight carbon foams and administrations heat equivalent to aluminum on the contrary at one-fifth the weight. The make open porosity of the foam allows fluids, of the like kind as air or water, to pass end it. This property, combined with the high surface area, leads to true high heat transfer ...