Designing free-standing 3D lamellar/pillared RGO/CNTs aerogels with ultra-high conductivity and compressive strength for elastic energy devices

Abstract

Mechanically compressible energy devices represent one of the most promising candidates for powering flexible and portable electronics, but often suffer from their limited stability of performance under high compressive strains. We here demonstrate a type of reduced graphene oxide/carbon nanotubes (RGO/CNTs) composite aerogel with high conductivity and compressive strength for elastic energy conversion and storage devices with high performance. The catalyst for growth of CNTs is loaded in the RGO aerogel by a simple solution method, and then, highly aligned CNT arrays are directly grown among RGO layers through chemical vapor deposition. The pillared CNT arrays between lamellar RGO layers provide the RGO/CNTs aerogel with extremely high conductivity (214.7 S m⁻¹) and compressive strength (73.6 kPa), which are superior to most previously reported results. With using the RGO/CNTs derived composite aerogels as electrodes, the achieved supercapacitors not only exhibit high specific capacitance (215.5 mF cm⁻³), but also show outstanding compression stability without performance degradation even after 15 000 repeated compression cycles. Furthermore, the piezoelectric nanogenerator based on the RGO/CNTs-derived aerogel can deliver a stable piezoelectric voltage of 0.6 V and excellent stability. This lamellar/pillared RGO/CNTs aerogel can be used as an efficient platform to load other functional materials for other elastic electronics with high performance.