Effects of different conductive ions on pore-structure evolution of medium- and high-rank coal bodies induced by electric pulses

•The change law of different conductive ions adsorbed by coal was studied to improve the conductivity of coal.•The variation law of breakdown strength of coal samples was studied, so as to improve the safety and efficiency of pulsatted coal.•The change characteristics of fracture structure in medium - and high - rank coal body was studied to promote gas permeability and desorption.