Facile Processing of Free-Standing Polyaniline/SWCNT Film as an Integrated Electrode for Flexible Supercapacitor Application

Flexible supercapacitors (SCs) with compact configuration are ideal energy storage devices for portable electronics, owing to their original advantages (e.g., fast charging/discharging). To effectively reduce the volume of SCs, an integrated electrode of free-standing polyaniline (PANI)/single-wall carbon nanotube (SWCNT) film with high performance has been developed via a facile solution deposition method, which can be employed as current collector and active material in the meantime. Thanks to the strong π-π interactions between PANI and CNTs, an efficient conductive network with ordered PANI molecular chains is formed in this hybrid film electrode, which is beneficial for the ion diffusion process and fast redox reaction resulting in a high capacitance of 446 F g^-1 and outstanding cycling stability, achieving 98% retention over 13 000 cycles. Predictably, solid-state SCs constructed by this free-standing PANI/SWCNT film electrode exhibited remarkable mechanical stability and flexibility in a compact configuration, let alone its excellent capacitive performance (218 F g^-1). Moreover, the highest energy density of flexible solid-state SC reached 19.45 Wh kg^-1 at a power density of 320.5 W kg^-1, further indicating a good potential as an energy storage device. This work would inspire other simple process techniques for high-performance flexible SCs, catering to the demand of portable electronic devices.