B/N-doped graphdiyne as superior supercapacitor electrode with record high quantum capacitance

•B/N-doped graphdiyne exhibits record high quantum capacitance for supercapacitors.•Low formation energies of B/N doping in graphdiyne suggest facile synthesis.•B/N-doping transforms graphdiyne into a metal, beneficial for high conductivity.•Graphdiyne shows promise for energy storage applications with tunable properties.