Core-shell cathode and a lithium-sulfur battery using the same

A lithium-sulfur battery, which is characterized by comprising:

• a lithium anode, a separator, a core-shell cathode, and an electrolyte;
• wherein the core-shell cathode comprises:
• a shell, comprising an electrically conductive, porous carbon material;
• and
• a core, which is an inner cavity enclosed within the shell, wherein the core contains an active material and an electrolyte, and the active material comprises liquid polysulfide having the general formula Li2Sx, wherein 4≤x≤8;
• the shell comprises a first layer, an O-ring and a second layer sequentially stacked from bottom to top to form the inner cavity to contain the active material and the electrolyte;
• and
• the lithium-sulfur battery has an electrolyte-to-sulfur ratio of between 3 μL/mg and 7 μL/mg;
• the electrically conductive, porous carbon material has a total pore volume of between 0.3 cm3/g and 0.55 cm3/g, and an average pore diameter of between 10 nm and 40 nm.