▎ 摘　　要

Highly uniform, ultrathin, layer-by-layer heteroatom (N, B) co-doped graphene films are fabricated for high-performance on-chip planar micro-supercapacitors with an ultrahigh volumetric capacitance of similar to 488 F cm(-3) and excellent rate capability due to the synergistic effect of nitrogen and boron co-doping.