A kind of preparation method of membrane electrode of lithium ion battery

Abstract

The invention relates to a preparation method of a lithium-ion battery membrane electrode, comprising: preparing a lithium-ion membrane matrix; taking lithium-ion negative electrode materials and lithium-ion positive-electrode materials and grinding them uniformly with a conductive agent respectively, drying them for later use; taking a polymer ester solution and adding After mixing N-methylpyrrolidone and negative electrode drying material, apply it to one side of the lithium-ion membrane substrate and dry it; take the polymer ester solution and add N-methylpyrrolidone and positive electrode drying material to stir, and then coat it on the lithium ion membrane substrate. The other side of the ionic membrane matrix is ​​dried and pressed into shape; the pressed product is pressed to obtain a lithium-ion battery membrane electrode; the obtained lithium-ion battery membrane electrode is placed in the battery case and dripped with electrolyte to make the membrane electrode fully Absorb and dry the unabsorbed electrolyte on the surface to obtain a membrane electrode full battery. The lithium ion battery membrane electrode prepared by the method has fast ion conduction, excellent electrode reaction reversibility, good cycle performance and safety performance, simple preparation process, low production cost, and is favorable for commercial production.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a method for preparing a membrane electrode of a lithium ion battery. Background technique [0002] The positive electrode material and the negative electrode material of the traditional lithium-ion battery are connected through a separator, and the electrode composite material of the positive and negative electrode layers is formed by coating aluminum foil and copper foil with a binder. Although this process has certain advantages, it also has some disadvantages: the binding force between the electrode active material and the metal foil is relatively poor. Volume expansion and contraction occur, and the resulting mechanical stress causes the electrode material to gradually change during the cycle, causing cracking and peeling of the electrode and metal foil, resulting in large polarization of the battery, serious capacity loss, and poor cycle performance , shorten...

AI Technical Summary

Problems solved by technology

Although this process has certain advantages, it also has some disadvantages: the binding force between the electrode active material and the metal foil is relatively poor. Volume expansion and contraction occur, and the resulting mechanical stress causes the electrode material to gradually change during the cycle, causing cracking and peeling of the electrode and metal foil, resulting in large polarization of the battery, serious capacity loss, and poor cycle performance , shortened service life

At present, the separator of lithium-ion batteries is a thin film with a microporous structure, which enables lithium ions to be transported through the micropores, but its mechanical properties are restricted by porosity.