AbstractBecause of their exotic electronic properties and abundant active sites, two-dimensional (2D) materials have potential in various fields. Pursuing a general synthesis methodology of 2D materials and advancing it from the laboratory to industry is of great importance. This type of method should be low cost, rapid and highly efficient. Here, we report the high-yield synthesis of 2D metal oxides and hydroxides via a molten salts method. We obtained a high-yield of 2D ion-intercalated metal oxides and hydroxides, such as cation-intercalated manganese oxides (Na_0.55Mn₂O₄·1.5H₂O and K_0.27MnO₂·0.54H₂O), cation-intercalated tungsten oxides (Li₂WO₄ and Na₂W₄O₁₃), and anion-intercalated metal hydroxides (Zn₅(OH)₈(NO₃)₂·2H₂O and Cu₂(OH)₃NO₃), with a large lateral size and nanometre thickness in a short time. Using 2D Na₂W₄O₁₃ as an electrode, a high performance electrochemical supercapacitor is achieved. We anticipate that our method will enable new path to the high-yield synthesis of 2D materials for applications in energy-related fields and beyond.