Compressible, Fatigue Resistant, and Pressure-Sensitive Carbon Aerogels Developed with a Facile Method for Sensors and Electrodes

Abstract

Carbon aerogels possess low density, high conductivity, and excellent electrochemical properties, which have potential applications in sensor and energy storage. However, the fabrication methods of carbon aerogels are very complicated, and the applications are usually restricted by their low compressibility, fragile structure, and poor electrical property. Herein, we report a very facile approach for the preparation of compressible, fatigue resistant, conductive, and pressure-sensitive carbon aerogels by pyrolysis of cellulose nanofibers aerogel using melamine foams as the skeleton. The wet aerogels are dried directly in ambient pressure without any volume shrinkage, which is remarkably contrasted to the complex and time-consuming drying process of traditional aerogels. The resulting carbon aerogels exhibit excellent performance, including a low density of 11.23 mg cm–3, high electrical conductivity of 0.378 S cm–1, high sensitivity of 1.841 kPa–1, and outstanding mechanical properties. The assembled carbon aerogel sensors can monitor human activities and pulse vibration, demonstrating the great potential application in wearable devices. Moreover, the high nitrogen content and hydrophilic property enable the carbon aerogels to be used as compressible electrodes with a specific and areal capacitance of 92.2 F g–1 and 461 mF cm–2, respectively, showing the promising prospect in flexible supercapacitors.