A 3D interconnected Cu network supported by carbon felt skeleton for highly thermally conductive epoxy composites

Effective heat removal through polymer composites has become a crucial issue in thermal management. Constructing a 3D interconnected filler network in polymer matrix is generally considered to be one of the most effective strategies for enhancing thermal conductivity of polymer-based composites. Herein, a unique 3D interconnected Cu network was successfully fabricated to enhance the thermal transfer properties of epoxy composites. We used Carbon felt (CFelt) as 3D skeleton to electroplate Cu on the CFelt surface for constructing the 3D Cu film network, which can serve as continuous heat conductive highways. The highly thermally conductive epoxy composites were then prepared by impregnating epoxy resin into the 3D Cu-plated CFelt (Cu-CFelt) network. Taking advantage of the 3D interconnected Cu heat transfer channel, an ultrahigh thermal conductivity of 30.69 W m −1  K −1 was achieved, which exhibited nearly 140 times higher than that of pure epoxy (0.22 W m −1  K −1 ) and 110 times higher than that of CFelt/epoxy composite (0.28 W m −1  K −1 ). And our composite exhibited outstanding thermal behaviors during heating and cooling processes. Additionally, the obtained composite maintained good mechanical properties and presented superior electrical conductivity of 7.49 × 10 4  S cm −1 . Our work reveals that the novel 3D Cu-CFelt/epoxy composites have strong application prospects in thermal management materials.