Developing Elastic, Robust, and Highly Porous Metal Foams Using Carbon Nanotube Scaffolds

It is important to develop flexible and conductive materials for various wearable applications, whereas metal foams are seldom used because of their thick cell walls, rigidity, and lack of elasticity. Based on an elastic three-dimensional scaffold (foam) of carbon nanotubes (CNTs), we demonstrate a strategy to develop lightweight metal foams with super high porosity, elasticity, and robustness. It is realized by depositing Pt particles onto the interior surfaces of CNT foam, followed by coating of polydimethylsiloxane for stabilization. The conductivity was improved from several S m–1 of the raw CNT foam up to more than 100 S m–1, and the low resistance was maintained perfectly upon compressing up to 70%. The improved elastic stability ensured excellent antifatigue performance beyond 1000 cyclic compressive tests. As compared to conventional metal foam, the CNT/Pt composite foam exhibited a much higher surface area of 42.5 m2 g–1 at a low mass density of just 0.04 g cm–3.