Scalable Preparation of Ultrathin Graphene-Reinforced Copper Composite Foils with High Mechanical Properties and Excellent Heat Dissipation.

As an important basic material of electronic equipment, copper (Cu) foils should have a small thickness, good mechanical properties, and excellent thermal conductivity. However, preparing an ultrathin Cu foil with good properties remains challenging. Herein, we report an electroless deposition (ELD) strategy for the facile and scalable preparation of an ultrathin freestanding nickel-coated graphene (NCG)/Cu composite foil in a short time of 25 min. The NCG can significantly improve the mechanical and physical properties of composite foils. Experimental results reveal that the NCG/Cu composite foil manifests the best performance when the NCG concentration in an ELD bath was 30 mg/L. The composite foil evidenced a thickness of 1.1 μm, a high tensile strength of 338.7 MPa, and a high thermal conductivity of 431.2 W/mK. Compared with the pure Cu foil, both bending times and elastic modulus are increased by 298.1 and 737.3%, respectively. Remarkably, the composite foil has excellent heat dissipation performance, showing enormous potential as a heat sink material. This work proposes a new method for manufacturing the ultrathin graphene-reinforced Cu composite foil with high performance for numerous applications.