Self‐Supported Fluorine‐Doped Boron Carbonitride Porous Aerogels for High‐Performance Supercapacitors

Carbon materials have long been extensively used in supercapacitors. However, the practical application of carbon‐based supercapacitors has been severely limited by their low charge storage capacity. Rational construction of carbon materials with heteroatom doping and high specific surface area can effectively improve the performance of supercapacitors. Therefore, a self‐supported fluorine‐doped boron carbonitride (F‐BCN) aerogel material for the application of supercapacitors is designed. The introduction of heteroatoms increases the defect density of the carbon skeleton, expands the interlayer spacing, and generates abundant electrochemical active sites, thereby promoting the diffusion of ions in the electrode. The specific capacitance of F‐BCN‐3 is 524.9 F g −1 at a specific current of 1 A g −1 , with which the assembled symmetric supercapacitor exhibits a maximum energy density of 11.75 W h kg −1 . The symmetric supercapacitor can maintain a specific capacitance of 83% after 5000 charge and discharge cycles, showing good electrochemical cycle stability. The design concept provides a promising guide for further applications of carbon materials in energy storage devices.