Sulfur/carbon composite material for lithium-sulfur secondary battery and preparation method thereof

The invention discloses a sulfur/carbon composite material for a lithium-sulfur secondary battery and a preparation method thereof. The composite material is formed by compositing a micro-pore carbon substrate with a lithium ion conduction property and elemental sulfur filled in the micro-pore structure. The carbon substrate is used as an electronic conductor in the composite material, and is further used as a lithium ion conductor, so that sulfur electrode reaction is directly carried out on a sulfur/carbon solid-solid interface in a conversion reaction manner without directly contacting with electrolyte. Therefore, the problem of circulation caused by that a polysulfide intermediate product is dissolved in the electrolyte can be solved. Compared with the other sulfur/carbon composite electrode, the composite material has the advantages of high electrochemical capacity, good circulation stability, high charging and discharging efficiency and the like; and meanwhile, the preparation method is simple and low in cost, and has a good application prospect.