Flexible and multi-form solid-state supercapacitors based on polyaniline/graphene oxide/CNT composite films and fibers

Solid-state supercapacitors (SSCs) are under intensive study during recent years; rational design of the electrode structure and device configuration is essential to bring high performance and enable flexibility. Here, we designed a mutually intercalated composite structure consisting of pseudo-polymer (polyaniline, PANI), graphene oxide (GO) and carbon nanotubes (CNTs), in various forms such as planar films or helical fibers. In the prepared PANI/GO/CNT composite films, PANI and GO were uniformly embedded among stacked CNT networks resulting in a synergistic effect from all components; as a result, the film with tunable PANI loading exhibited a specific capacitance of 729.3 F/g (510.5 mF/cm2) at 1 A/g in three-electrode configuration, and symmetric SSCs made by these films showed stable performance upon large-degree bending for 500 cycles. The composite film was further over-twisted into a helical fiber and constructed to fiber-shaped SSCs, which could work stably at elongations as much as 80%. Our polymer/carbon nanostructure composite electrodes that can work under different forms (films or fibers) have potential applications as flexible, stretchable and wearable energy storage devices and textiles.