Mesoporous carbon spheres with tunable porosity prepared by a template-free method for advanced lithium–sulfur batteries

Mesoporous carbon spheres (MCS) are prepared by a spray-drying process using chitosan as carbon precursor with ethanol as porosity tuning agent. MCSs with different porosity are deduced by manipulating the volume ratio of ethanol in the solvent for chitosan. The resulted MCSs show controllable surface areas, pore volumes and bimodal pore size distribution. They are employed as substrates for the preparation of sulfur/carbon composite cathode with superior electrochemical performance.