Self‐Supporting GaN Nanowires/Graphite Paper: Novel High‐Performance Flexible Supercapacitor Electrodes

Flexible supercapacitors have attracted great interest as energy storage devices because of their promise in applications such as wearable and smart electronic devices. Herein, a novel flexible supercapacitor electrode based on gallium nitride nanowire (GaN NW)/graphite paper (GP) nanocomposites is reported. The outstanding electrical conductivities of the GaN NW (6.36 × 102 S m−1) and GP (7.5 × 104 S m−1) deliver a synergistically enhanced electrochemical performance that cannot be achieved by either of the components alone. The composite electrode exhibits excellent specific capacitance (237 mF cm−2 at 0.1 mA cm−2) and outstanding cycling performance (98% capacitance retention after 10 000 cycles). The flexible symmetric supercapacitor also manifests high energy and power densities (0.30 mW h cm−3 and 1000 mW cm−3). These findings demonstrate that the GaN/GP composite electrode has significant potential as a candidate for the flexible energy storage devices.