Electrode material, method for manufacturing electrode material, and secondary battery

Abstract

An electrode material is provided. The electrode material includes a porous carbon material, wherein the porous carbon material has a half-width of diffraction intensity peak of a (100) face or a (101) face of 4 degrees or less with reference to a diffraction angle 2 theta on a basis of an X-ray diffraction method. An absolute value of a differential value of mass can be obtained when a mixture of the porous carbon material and S8 sulfur mixed at a mass ratio of 1:2 is subjected to thermal analysis, where temperature is employed as a parameter, has a value of more than 0 at 450° C. and a value of 1.9 or more at 400° C. A battery and method of manufacture are also provided.

Description

technical field [0001] The present disclosure generally relates to electrode materials, methods of manufacturing electrode materials, and secondary batteries. Background technique [0002] A lithium-sulfur secondary battery has been developed in which sulfur alone is used as a positive electrode active material and lithium (Li) is used as a negative electrode active material. The theoretical capacity densities of lithium and sulfur are about 3862 mAh / g and about 1672 mAh / g, respectively, and it is considered that a secondary battery having a very high energy density can be obtained. However, in fact: [0003] (1) The utilization rate of sulfur as a positive electrode active material is very low, and [0004] (2) The charge-discharge cycle characteristics are poor. These are the reasons why lithium-sulfur secondary batteries that may be mentioned have not been commercialized at the present stage. A very large theoretical capacity density characteristic of lithium-sulfur se...

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Problems solved by technology

[0003] (1) The utilization rate of sulfur as a positive electrode active material is very low, and

[0004] (2) The charge-discharge cycle characteristics are poor. These are the reasons why the lithium-sulfur secondary batteries that may be mentioned have not been commercialized at this stage

In addition, there is also a problem that at the time of charging, the cut-off voltage is not reached and an overcharged state is caused due to redox shuttle reaction in which many eluted in the electrolytic solution Sulfides are reduced at the negative electrode to generate polysulfides with shorter sulfur chains and the resulting polysulfides are moved to the positive electrode where they are oxidized again

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