Full solid-state lithium-sulfur battery and manufacturing method thereof

Abstract

The invention belongs to the technical field related to the preparation of the lithium ion battery, and discloses a full solid-state lithium-sulfur battery. The full solid-state lithium-sulfur batterycomprises a metal negative electrode, a sulfide solid electrolyte and a composite positive electrode; the material of the metal negative electrode is selected from one of Li metal, Li-In alloy, Li-Alalloy, Li-Si alloy or Li-Sn alloy; the sulfide solid electrolyte is selected from one or combination of Li10GeP2S12 type solid electrolyte, Li2S-P2S5 glass-state electrolyte, and argyrodite type solid electrolyte; the composite positive electrode is commonly composed of selentellurium-doped sulfide polyacrylonitrile, a positive solid electrolyte with components same as that of the sulfide solid electrolyte, and a carbon-based conductive additive in a specific proportion. The invention further discloses a corresponding manufacturing method. Through the full solid-state lithium-sulfur battery disclosed by the invention, the defect that the conventional full solid-state lithium-sulfur battery is low in rate performance and low in active substance utilization efficiency can be well overcome,and a three-phase interface of the active substance, the solid electrolyte and the conductive auxiliary is optimized at the same time.

Description

technical field [0001] The invention belongs to the technical field related to the preparation of lithium-ion batteries, and more specifically relates to an all-solid-state lithium-sulfur battery and a manufacturing method thereof. Background technique [0002] As the most advanced secondary battery at this stage, lithium-ion batteries are recognized as the first choice for the core supporting power supply of electric vehicles. The current lithium-ion batteries mainly use various intercalation compounds as electrode materials, and energy storage and release are realized through the intercalation and deintercalation of lithium ions between the positive and negative electrodes. Since intercalation materials are generally based on single-electron reactions, and the chemical formula of the material is large, the electrode capacity is obviously low, which limits the energy density of the battery. For example, a typical cathode material LiCoO 2 and LiFePO 4 The specific capacit...

AI Technical Summary

Problems solved by technology

However, due to the chemical properties of the material itself, sulfur and lithium form soluble polysulfides and dissolve in the electrolyte during the battery cycle; and traditional lithium-sulfur batteries using electrolytes have safety issues caused by lithium dendrites

[0004] A new search search found that although some solid electrolytes have been proposed in the prior art to solve the problem of polysulfide dissolution and inhibit the growth of lithium dendrites, further research has shown that due to the electronic insulation and low ion density of sulfur Transmission characteristics, as well as solid-solid contact problems in solid-state batteries, all-solid-state lithium-sulfur batteries often have poor rate performance in actual tests, and the capacity of the active material sulfur is difficult to play

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