All-solid-state lithium-ion battery and manufacturing method thereof

Abstract

The invention discloses an all-solid-state lithium-ion battery and a manufacturing method thereof. The manufacturing method comprises the following steps of (1) dissolving a polymer electrolyte into a solvent to prepare a glue solution; (2) fully mixing a positive electrode host material, a conductive agent and the glue solution obtained in the step (1), coating a positive current collector, heating the positive current collector and then carrying out co-curing to obtain a positive electrode plate, fully mixing a negative electrode host material, the conductive agent and the glue solution obtained in the step (1), coating a negative current collector, heating the negative current collector and then carrying out co-curing to obtain a negative electrode roll; (3) carrying out mechanical ball milling on a sulfide electrolyte, dissolving the product into the solvent to prepare slurry, coating the surface of the negative electrode roll, heating the negative electrode roll and then curing the negative electrode roll to obtain a negative electrode plate; and (4) assembling the positive electrode plate and the negative electrode plate by adopting a lamination technology to obtain the all-solid-state lithium-ion battery. Compared with the prior art, the all-solid-state lithium-ion battery disclosed by the invention has relatively low DC resistance, relatively high ionic conductivity and good cycle performance.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and in particular relates to an all-solid lithium ion battery and a manufacturing method thereof. Background technique [0002] Lithium-ion batteries are regarded as one of the most competitive electrochemical energy storage technologies due to their light weight, high specific energy / specific power, low self-discharge, and long life. Current commercial lithium-ion batteries widely use liquid electrolytes, which are characterized by high electrical conductivity and excellent electrochemical performance. However, the liquid electrolyte has a low flash point, which may cause the electrolyte to heat up and spontaneously ignite under abnormal conditions such as high-current discharge, overcharging, and internal short circuit, and even cause safety problems such as explosion. An all-solid-state battery using a solid-state electrolyte greatly improves safety, simplifies battery safety devices, and...

AI Technical Summary

Problems solved by technology

However, there are also some disadvantages in the application of sulfide solid electrolytes. At the electrode / solid electrolyte interface, since the force between oxygen-lithium ions is much stronger than the force between sulfur-lithium ions, when the oxide positive electrode has both ionic conductivity and When an electronically conductive mixed conductor is used, a space charge layer will be generated at the electrode / electrolyte interface, thereby forming a base-type space charge layer, so that the interface between the electrode / solid electrolyte forms a high resistance to the movement of lithium ions, resulting in battery Has high DC internal resistance and poor cycle performance

Polymer solid electrolytes, such as thin films formed by the complexation of lithium salts and linear polyether, have the characteristics of high electrochemical and chemical stability and easy curing, but due to the solid polymer formed by polymers and lithium salts The electrolyte has a high crystalline phase at room temperature, which also leads to high DC internal resistance and poor cycle performance of the battery

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