A sulfur-carbon composite including a porous carbon material; and sulfur present in at least a part of pores of the porous carbon material and on an outer surface of the porous carbon material, wherein an inner surface and the outer surface of the porous carbon material are doped with a carbonate compound. Also, a positive electrode and a secondary battery including the same. Further, a method of preparing a sulfur-carbon composite and a method of preparing a positive electrode.

A method for producing an electrode for a storage device for storing electrical energy is provided. A main body of the electrode is coated with at least one active material for storing electrical energy. A mixture, which includes the active material and fibers, is provided. The main body is coated with the mixture, which is free of a solvent that receives the fibers and escapes at least predominantly from the mixture after coating of the main body. By coating the main body with the mixture, a coating which includes the active material and the fibers is formed on the main body from the mixture.

This secondary battery comprises a positive electrode, a negative electrode, and an electrolyte. The electrolyte contains a solvent containing water, and a lithium salt. The negative electrode has a negative electrode active material that contains a carbon material. In the carbon material, the peak intensity ratio (D/G value) of a D band and a G band in the Raman spectrum obtained using Raman spectroscopy is 0.9 to 1.5. A coating is formed on the surface of the carbon material. In the coating, in the XPS spectrum measured using X-ray photoelectron spectroscopy, when the peak intensity of a 1s electron orbit of an F atom for which the binding energy appears near 685 eV is P1, and the peak intensity of the 1s electron orbit of an O atom for which the binding energy appears near 532 eV is P2, the ratio of the peak intensity P1 to the peak intensity P2 (P1/P2 value) is 0.6 to 3.0.

This secondary battery comprises a positive electrode, a negative electrode, and an electrolyte solution. The electrolyte solution includes a solvent containing water as a main component, and a lithium salt. The negative electrode has a negative electrode active material that includes a carbon material. The Raman spectrum of the carbon material, which is obtained by Raman spectroscopy, indicates that the peak intensity ratio between the D-band and the G-band (D/G) is 0.3 or greater. This secondary battery can suppress the reductive decomposition of the water-based electrolyte solution.

A porous reduced graphene oxide containing pores of 2 to 500 nm, a preparation method thereof, a sulfur-carbon composite and a lithium secondary battery comprising the same.

A porous reduced graphene oxide containing pores of 2 to 500 nm, a preparation method thereof, a sulfur-carbon composite and a lithium secondary battery comprising the same.

An electrolyte solution for a lithium secondary battery, including a first solvent comprising a heterocyclic compound haying at least one double bond, and any one of an oxygen atom and a sulfur atom; a second solvent including at least one of an ether-containing compound, an ester-containing compound, an amide-containing compound, and a carbonate-containing compound; a lithium salt; lanthanum nitrate; and an additive including lithium nitrate.

An electrolyte solution for a lithium secondary battery, including a first solvent comprising a heterocyclic compound haying at least one double bond, and any one of an oxygen atom and a sulfur atom; a second solvent including at least one of an ether-containing compound, an ester-containing compound, an amide-containing compound, and a carbonate-containing compound; a lithium salt; lanthanum nitrate; and an additive including lithium nitrate.

An electrolyte solution for a lithium secondary battery including a first solvent containing a heterocyclic compound having at least one double bond and any one of an oxygen atom and a sulfur atom; a second solvent containing at least one of an ether-containing compound that does not contain fluorine, an ester-containing compound, an amide-containing compound, and a carbonate-containing compound; a third solvent containing a hydrofluoro ether-containing compound; a lithium salt; lanthanum nitrate; and lithium nitrate.

An electrolyte solution for a lithium secondary battery including a first solvent containing a heterocyclic compound having at least one double bond and any one of an oxygen atom and a sulfur atom; a second solvent containing at least one of an ether-containing compound that does not contain fluorine, an ester-containing compound, an amide-containing compound, and a carbonate-containing compound; a third solvent containing a hydrofluoro ether-containing compound; a lithium salt; lanthanum nitrate; and lithium nitrate.