All-carbon-based semimetal for sodium-ion batteries anode material: A first principle study

•The results show that the diffusion energy barrier of Na in Bco-C16 is small, indicating an excellent mobility rate.•The volume changes little and the conductivity becomes better in the charging process.•It is sspeculated that Bco-C16 could be a promising anode material for NIBs by the first-principle calculations.