▎ 摘　　要

NOVELTY - A graphene oxide (GO) coating comprises a GO layer comprising a GO dispersion chosen from type I GO corresponding to original GO prepared by a modified Hummers method and functionalized with a carboxyl group, type II GO corresponding to GO with enlarged structural defects etched by a nitric acid oxidation, and type III GO with reduced lateral size synthesized ultrasonically. USE - Graphene oxide coating used for separator membrane of lithium-sulfur battery (claimed) used for hybrid electric vehicles and electric vehicles. ADVANTAGE - The coating is economical, reduces greenhouse emissions, and has high ion selectivity. The battery has excellent mechanical strength and chemical/electrochemical stability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) lithium-sulfur battery (100), which consists of a lithium metal anode (102), a polysulfide cathode (104), and a composite membrane comprising a polymeric separator membrane (106) and at least one graphene oxide (GO) coating layer on the polymeric separator membrane formed by printing a GO dispersion on the polymeric separator membrane positioned between the lithium metal anode and the polysulfide cathode; and (2) manufacture of composite membrane (110), which involves providing a polymeric separator membrane, synthesizing a (GO) dispersion, and printing the GO dispersion onto at least one surface of the polymeric separator membrane to form a GO coating comprising a GO layer. DESCRIPTION OF DRAWING(S) - The drawing shows a cross section of the lithium-sulfur battery. Lithium-sulfur battery (100) Lithium metal anode (102) Polysulfide cathode (104) Polymeric separator membrane (106) Composite nanoporous ultrathin membrane (110)