Electrode structure of lithium sulfur battery and processing technology therefor

Abstract

The invention discloses an electrode structure of a lithium sulfur battery and a processing technology therefor. The electrode structure comprises a sulfur-containing active substance layer and a current collector; the upper surface of the active substance layer is coated with a first carbon coating layer; the lower surface of the active substance layer is coated with a second carbon coating layer; and the second carbon coating layer is positioned between the active substance layer and the current collector. The electrode structure has the main characteristics that the two sides of the sulfur-containing active substance layer are coated with the carbon coating layers; namely, the surface of the active substance layer, and the space between the active substance layer and the current collector are coated with the carbon coating layers, wherein a carbon material is taken as the main component, and the carbon material with a large specific surface area or low bulk density is preferable; the carbon material with the relatively large specific surface area can absorb polysulfide and restrain a shuttle effect; meanwhile, the carbon material with the low bulk density can form the relatively loosen carbon coating layer so as to store a large amount of electrolyte in the carbon coating layer, and the dissolution of sulfur and the polysulfide is facilitated, a positive electrode reaction is promoted, and the increase of electrolyte viscosity caused by resolution is restrained.

Description

technical field [0001] The invention belongs to the technical field of lithium-sulfur batteries, and in particular relates to an electrode structure of a lithium-sulfur battery. Background technique [0002] In the lithium-sulfur battery system, metal lithium is used as the negative electrode and elemental sulfur is used as the positive electrode. The theoretical specific energy can reach 2600Wh / kg, which is much larger than modern commercial lithium-ion batteries. In addition, elemental sulfur also has the characteristics of low price and environmental friendliness. Therefore, lithium-sulfur batteries have high potential for commercial application. However, lithium-sulfur batteries also have many problems. The most important of these is that the utilization rate of sulfur is low during the charging and discharging process, and the capacity decays rapidly during the cycle. [0003] At present, it is believed that the reasons for this problem include many aspects, one of w...

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Problems solved by technology

[0006] The technical problem to be solved by the present invention is: in order to solve the problems of low sulfur utilization rate and short cycle life of the lithium-sulfur battery positive electrode, the patent of the present invention proposes a three-layer electrode preparation with simple preparation, thin thickness, light weight, and cheap and easy-to-obtain raw materials. technology, so that it can not only have a good ability to improve the performance of lithium-sulfur batteries similar to independent self-supporting carbon interlayers, but also is simple and easy to use

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