A cathode electrode material and a lithium sulfur battery are disclosed. The cathode electrode material includes the cathode binder. The cathode binder includes a polymer obtained by polymerizing a dianhydride monomer with a diamine monomer. At least one of the dianhydride monomer and the diamine monomer includes a silicon-containing monomer. The lithium sulfur battery includes an anode electrode, an electrolyte, and the cathode electrode, the cathode electrode includes a sulfur containing cathode active material, a conducting agent, and the cathode binder.