Pore engineering: Structure-capacitance correlations for biomass-derived porous carbon materials

•Pore size shows significant effect on the capacitive performance of biomass-derived porous carbon materials.•Pore characteristics are influenced by the probe molecules and the corresponding calculation models.•The microstructure of biomass derived porous carbon is influenced by the structure and components of precursor and synthesis method.•Challenges are existing and new strategies are required to boost the capacitance performance of biomass derived porous carbon.