Abstract Biomass carbon material derived from dandelion was synthesized by pyrolysing with controlled pseudographtic domain dimension at different temperatures. These domains exhibit larger volume with expanded the average width (L a ), thickness (L c ) and the average number of graphite layers (n) when increasing the pyrolysing temperature. When tested as anodes in Na-ion battery, the electrochemical results show the biomass carbon displays a superior specific capacity of 361 mAh g −1 at 50 mA g −1 . Further research finds increasing L a , L c and n leads to greatly higher plateau capacity below 0.1 V without changing sloping capacity above 0.1 V, indicating the amount of sodium ions de-intercalation between graphite layers is highly sensitive to the dimension of pseudographtic domain. Besides, overlarge dimension of pseudographtic domains are found to hinder the diffusion of Na + between the graphite layers with obvious capacity loss. This work suggests controlling pseudographtic domain dimension could provide practical reference to pursue higher Na + storage performance.