Reduced graphene oxide/polyaniline wrapped carbonized sponge with elasticity for energy storage and pressure sensor

Compressible materials have received great attention due to potential applications for energy storage and sensors in special cases. In the present work, reduced graphene oxide (RGO) was coated on carbon foam, and polyaniline (PANI) nanorods were grown on it to synthesize a compressible ternary composite. In this scenario, carbon foam was carbonized and used as a three-dimensional conductive and compressible framework; RGO nanosheets were the growth carrier of PANI which provided high pseudocapacitance. Due to the conservation of elasticity after carbonization, the device can be fully restored after compression strain and the electrochemical performance remained stable. As electrodes of a supercapacitor, a specific capacitance of 533 F g−1 was achieved in a two-electrode configuration. After 2000 charge–discharge cycles at 10 A g−1, 86.7% of the initial capacitance was retained. Meanwhile, this material as a piezoresistive pressure sensor has high sensitivity to 13.6 kPa and can be used to detect continuous stress variation. The presented composite material with excellent piezoresistive sensitivity and electrochemical performance shows broad prospects in the field of wearable devices.