Positive electrode material for lithium-sulfur battery, preparation method thereof, and lithium-sulfur battery

Abstract

Disclosed is a positive electrode material for a lithium-sulfur battery, including a sulfur-containing positive electrode material and a transition metal compound, the transition metal compound can generate a transition metal sulfide when the lithium-sulfur battery is discharged, and the transition metal sulfide is poorly soluble in in the electrolyte. In the positive electrode material of the present invention, in the lithium-sulfur battery system, the transition metal compound will form transition metal sulfide with polysulfide ions in the discharge product. The transition metal sulfide is insoluble in the electrolyte, so it can fix the polysulfide ions in the positive electrode, thereby blocking the shuttling of polysulfide at the root.

Description

technical field

[0001] The invention belongs to the field of chemical power sources, and in particular relates to a positive electrode material of a lithium-sulfur battery, a preparation method thereof and a lithium-sulfur battery containing the positive electrode material. Background technique

[0002] The theoretical capacity and specific energy of lithium-sulfur batteries reach 1675mAh / g and 2600Wh / kg, which are much higher than the energy density (<300wAh / kg) of iron-lithium or ternary batteries widely used in commerce, and elemental sulfur is abundant in the earth , has the characteristics of low price and environmental friendliness. Therefore, lithium-sulfur batteries are widely considered to be the development direction of next-generation high-energy-density batteries, and they are also a research hotspot for high-energy-density batteries.

[0003] However, elemental sulfur reacts with lithium ions during the electrochemical reaction to form lithium polysulfide (L...

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