▎ 摘　　要

NOVELTY - Preparation of sodium ion supercapacitor involves depositing boron-doped diamond film on a tantalum or titanium sheet by electron assisted hot wire chemical vapor deposition, changing the experimental parameters, directly preparing boron-doped graphene on the boron-doped diamond film, forming boron-doped graphene/boron-doped diamond composite film, assembling obtained composite film as electrode, into electrolyte containing sodium ions and carrying out electrochemical performance testing of sodium ion supercapacitor using electrochemical workstation. USE - Preparation of sodium ion supercapacitor. ADVANTAGE - The method efficiently provides sodium ion supercapacitor having high energy density and temperature resistance, quick charging speed, long cycle life, and strong acid-alkali environment.