All-solid-state lithium–sulfur batteries were developed using elemental sulfur as a positive electrode, Li–Al alloy as a negative electrode, thio-LISICON as a solid electrolyte, and mesoporous carbon (CMK-3) as the framework for the positive electrode. The mesoporous framework provided high electrical conduction and improved electrode utilization. The sulfur provided a high reversible capacity and high current charge discharge characteristics. Sulfur introduced into the pore structure of the mesoporous carbon interacts with edges of the graphene sheet and both the sulfur and graphene layers participate in a highly reversible reaction.