Binder, method for preparing the binder, and electrode and lithium battery comprising the binder

Abstract

The present invention relates to binders, methods for preparing the binders, and electrodes and lithium batteries comprising the binders. The adhesive comprises a third polymer comprising a cross-linked product of a first polymer and a second polymer, wherein the first polymer comprises a first functional group and is selected from polyamic acid and poly At least one of imides, wherein the second polymer includes a second functional group and is water soluble, and wherein the first polymer and the second polymer are formed by the first functional group and the The reaction of the second functional group forms an ester bond to crosslink.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit and priority of Korean Patent Application No. 10-2016-0093461 filed on Jul. 22, 2016 at the Korean Intellectual Property Office, and all rights arising therefrom, the contents of which are incorporated herein by reference in their entirety . technical field [0003] The present disclosure relates to binders, methods of making the binders, and electrodes and lithium batteries including the binders. Background technique [0004] In lithium batteries with electrodes comprising carbonaceous active materials, water-soluble binders such as styrene-butadiene rubber / carboxymethylcellulose (SBR-CMC) binders provide suitable mechanical properties and adhesive properties to the battery. knot strength. [0005] In a lithium battery having an electrode including a metallic active material such as silicon that has a large volume change during charge / discharge, a water-soluble binder may not prov...

AI Technical Summary

Problems solved by technology

[0005] In lithium batteries having electrodes that include metallic active materials such as silicon that have large volume changes during charge / discharge, water soluble binders may not provide suitable mechanical properties or bond strength to the battery

[0006] Polyimide (PI) adhesives have desirable mechanical properties, chemical resistance, and heat resistance, but are insoluble in water and have low initial charge / discharge efficiency

[0007] Polyvinyl alcohol (PVA) binders are water-soluble and have desirable initial charge / discharge efficiency and lifetime characteristics, but poor workability with regard to slurry stability and electrode plate uniformity

In addition, when a PVA binder is used, cracks may be generated in the active material layer and the active material layer may be separated from the current collector, and thus the stability of the electrode decreases.

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