KR-20260062692-A - POROUS POLYMER SUPPORT AND NEGATIVE ELECTRODE COMPRISING THE SAME

KR20260062692AKR 20260062692 AKR20260062692 AKR 20260062692AKR-20260062692-A

Abstract

The present invention aims to provide a porous polymer support in which the growth of lithium dendrites is suppressed during the deposition of lithium, and a negative electrode for a secondary battery comprising the same.

Inventors

이정호
장의진
이문찬
김재윤
최광욱

Assignees

주식회사 엘지화학

Dates

Publication Date: 20260507
Application Date: 20241029

Claims (15)

It comprises a porous polymer support including a plurality of polymer fibers, and A negative electrode for a secondary battery, wherein a plurality of lithium nuclei are located on the fiber strands.
In paragraph 1, The above lithium nucleus is a negative electrode for a secondary battery having a major axis length of 10 nm to 10 μm.
In paragraph 1, A negative electrode for a secondary battery, wherein the coverage of the lithium nucleus with respect to the surface area of the porous polymer support is 5 to 25%.
In paragraph 1, A negative electrode for a secondary battery, wherein the coverage of the lithium nucleus is 5 to 25% in the thickness region from 1/4 depth to 3/4 depth of the total thickness in the thickness direction of the porous polymer support.
In paragraph 1, The above porous polymer support further comprises a conductive metal layer coating at least a portion of the surface of the fiber strands, for a negative electrode for a secondary battery.
In paragraph 5, The above conductive metal is one selected from the group consisting of copper, nickel, lithium, tin, aluminum, chromium, manganese, cobalt, molybdenum, sodium, titanium, gold, silver, chromium, niobium, zinc, and stainless steel, or is an alloy of two or more types, a negative electrode for a secondary battery.
In paragraph 5, The above conductive metal layer is one layer or two or more layers, a negative electrode for a secondary battery.
In paragraph 1, The above polymer fibers are polyethylene terephthalate, polyimide, polyamide, polysulfone, poly(vinylidene fluoride), polyacrylonitrile, polyethylene, polypropylene, polyetherimide, polyvinyl alcohol, polyethylene oxide, polyacrylic acid, polydimethylsiloxane, polyvinylpyrrolidone, agarose, alginate, polyvinylidene hexafluoropropylene, polyurethane, polypyrrole, poly 3,4-ethylenedioxythiophene (poly A negative electrode for a secondary battery comprising at least one selected from the group consisting of 3,4-ethylenedioxythiophene), polyaniline, and derivatives thereof.
In paragraph 1, A negative electrode for a secondary battery, wherein the thickness of the porous polymer support is 0.1 to 100 μm.
A step of preparing a porous polymer support comprising a plurality of polymer fibers; and A method for manufacturing a porous polymer support, comprising the step of forming a lithium nucleus having a major axis length of 10 nm to 10 μm on the fiber.
In Paragraph 10, A method for manufacturing a porous polymer support, wherein the lithium nucleus is formed with a coverage of 5 to 25% of the surface area of the porous polymer support.
In Paragraph 10, A method for manufacturing a porous polymer support, wherein the porous polymer support further comprises a conductive metal layer coating at least a portion of the surface of the fiber strands.
A secondary battery comprising a negative electrode of any one of claims 1 to 9; a positive electrode; and an electrolyte disposed between the negative electrode and the positive electrode.
It comprises a porous polymer support including a plurality of polymer fibers, and It includes a lithium active material layer located on the fiber strand, A negative electrode for a secondary battery, wherein the coverage of the lithium active material layer in the thickness region from 1/4 depth to 3/4 depth of the total thickness in the thickness direction of the porous polymer support is 70% or more.
In Paragraph 14, It further comprises a conductive metal layer covering at least a portion of the surface of the fiber, and A negative electrode for a secondary battery, wherein the lithium active material layer is located on the conductive metal layer.

Description

Porous polymer support and negative electrode comprising the same The present invention relates to a porous polymer support and a current collector or negative electrode for a lithium secondary battery comprising the same. With the rapid advancement of the electronics, telecommunications, and computer industries, the application fields of energy storage technology are expanding to include camcorders, mobile phones, laptops, PCs, and even electric vehicles. Accordingly, the development of high-performance secondary batteries that are lightweight, long-lasting, and highly reliable is underway. Among the secondary batteries currently in use, lithium secondary batteries developed in the early 1990s are gaining attention for their advantages of higher operating voltage and significantly higher energy density compared to conventional batteries such as Ni-MH, Ni-Cd, and lead-acid batteries that use aqueous electrolytes. Lithium metal, carbon-based materials, and silicon are used as negative electrode active materials for lithium secondary batteries; among these, lithium metal has the advantages of having the highest energy density compared to other negative electrode active materials, being lightweight, and possessing a high electrochemical potential. However, when lithium metal sheets are used as the negative electrode in lithium secondary batteries, there are safety issues such as internal short circuits or fire hazards due to the formation of lithium dendrites. Therefore, various methods are being studied to improve the stability of lithium metal electrodes. FIG. 1 is a schematic diagram illustrating the structure of a porous polymer support according to one embodiment of the present invention. Figure 2 is an SEM image of the porous polymer support of Example 1 and Comparative Example 1 observed in Experimental Example 1. Figure 3 is an SEM image showing the cross-section of the porous polymer support of Example 1 and Comparative Example 1 in Experimental Example 1. Figure 4 is an SEM image of the porous polymer support of Example 2 and Comparative Example 1 observed in Experimental Example 2. Figure 5 is a graph showing the change in the ratio of the desorption capacity to the electrodeposition capacity according to the number of cycles during the charge-discharge process, as a result of evaluating the lifespan characteristics of a coin-type asymmetric cell using Examples 1 to 4 and Comparative Examples 1 and 2 as electrodes in Experimental Example 3. Figure 6 is an SEM image showing lithium metal deposited on a porous polymer support after the completion of the charge-discharge experiment of a coin-type asymmetric cell using Example 1 and Comparative Example 1 as electrodes in Experimental Example 3. Unless otherwise defined in this specification, all technical and scientific terms are used merely to describe exemplary embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “comprising,” or “having” are intended to specify the presence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. The technical terms used in this specification are intended merely to refer to specific embodiments and are not intended to limit the invention. Furthermore, the singular forms used herein include plural forms unless the phrases clearly indicate otherwise. porous polymer support According to one embodiment of the present invention, the invention relates to a porous polymer support comprising a plurality of polymer fibers, wherein a plurality of lithium nuclei are located on the fiber strands. The porous polymer support described above has a structure comprising a plurality of fibers. More specifically, the porous polymer support is a three-dimensional network structure in which a plurality of fibers are interconnected, and a number of irregular spaces existing between the dispersed fibers form pores. The specific form of the porous polymer support is not particularly limited, but may include, for example, a nonwoven fabric, a web form, or a laminated form thereof. The average diameter of the fibers included in the porous polymer support may be 50 nm to 100 μm, 50 nm to 70 μm, 50 nm to 50 μm, or 50 nm to 30 μm, but is not limited thereto. In terms of chemical stability, it is preferable that the fibers in