US-12620573-B2 - Electrode including electrode active material having through-holes, lithium battery containing the same, and method of preparing the same

US12620573B2US 12620573 B2US12620573 B2US 12620573B2US-12620573-B2

Abstract

An electrode, a lithium battery including the same, and a method of preparing the electrode are provided. The electrode includes an electrode active material layer including an electrode active material and a binder; and an electrode current collector at a portion of the electrode active material layer and at one side of the electrode active material layer, or at a portion of the electrode active material layer between opposing sides of the electrode active material layer, wherein the electrode active material layer includes a plurality of through-holes.

Inventors

Donggeun Lee
Ilkyong KWON
Hyun Nam
Jinhyon Lee

Assignees

SAMSUNG SDI CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20220728
Priority Date: 20210728

Claims (19)

1 . An electrode, comprising: an electrode active material layer comprising an electrode active material and a binder; and an electrode current collector at a portion of the electrode active material layer on one side of the electrode active material layer or at a portion of the electrode active material layer between opposing sides of the electrode active material layer, wherein the electrode active material layer has a plurality of through-holes; wherein the electrode has: a first domain comprising the portion of the electrode active material layer and the electrode current collector; and a second domain comprising a remaining portion of the electrode active material layer and being free of the electrode current collector, and wherein the plurality of through-holes is in the second domain and the first domain is free of any through-hole of the plurality of through-holes.
2 . The electrode of claim 1 , wherein the electrode active material layer comprises: a first surface and a second surface opposing the first surface, a first side surface and a second side surface opposing the first side surface, wherein the first side surface is connected to length-direction terminal ends of the first surface and the second surface, and a third side surface and a fourth side surface opposing the third side surface, wherein the third side surface is connected to width-direction terminal ends of the first surface and the second surface, wherein the first domain is defined by the first surface, the second surface, the third side surface, and the fourth side surface, and comprises the electrode current collector between the first surface and the second surface, and the second domain is defined by the first surface, the second surface, the third side surface, and the fourth side surface, and is free of the electrode current collector between the first surface and the second surface.
3 . The electrode of claim 2 , wherein the electrode active material comprises a first surface area defined by a length-direction first distance and a width-direction first distance of the electrode active material layer, and the electrode current collector has a second surface area defined by a length-direction second distance and a width-direction second distance of the electrode current collector, wherein the second surface area of the electrode current collector is 50% or less of the first surface area of the electrode active material layer.
4 . The electrode of claim 2 , wherein a length-direction second distance of the electrode current collector is 50% or less of a length-direction first distance of the electrode active material layer, or a width-direction second distance of the electrode current collector is 50% or less of a width-direction first distance of the electrode active material layer.
5 . The electrode of claim 1 , wherein the electrode is a stretchable electrode, wherein the stretchable electrode is stretchable in at least one direction of a length direction or a width direction of the stretchable electrode.
6 . The electrode of claim 1 , wherein one side of the electrode comprises a first surface in which the plurality of through-holes is arranged, wherein a surface area of the first surface is 99% or less than a total surface area of the electrode.
7 . The electrode of claim 1 , wherein a ratio (d 1 /T 1 ) of an average diameter (d 1 ) of the plurality of through-holes to a thickness (T 1 ) of the electrode active material layer is 0.001 to 0.1.
8 . The electrode of claim 1 , wherein through-holes of the plurality of through-holes are regularly and periodically spaced apart in a uniform interval in the electrode active material layer, and comprise a lattice structure.
9 . The electrode of claim 1 , wherein an opening of each of the plurality of through-holes has at least one of a circular shape, an oval shape, a triangle shape, a rectangular shape, a pentagonal shape, a hexagonal shape, an alphabet shape, or a donut shape, each of the plurality of through-holes comprises an angle of 60 degrees to 120 degrees with the one side or the opposing sides of the electrode active material layer, and the electrode comprises a structure in which the electrode active material layer is alternatively arranged with the through-holes in a cross-sectional view.
10 . The electrode of claim 1 , wherein the electrode active material layer further comprises an interlayer between the electrode active material layer and the electrode current collector, wherein a thickness of the interlayer is 30% or less of a thickness of the electrode current collector.
11 . The electrode of claim 10 , wherein the interlayer comprises a second binder, wherein the second binder is at least one of a conductive binder or a non-conductive binder, and the binder is also a fluorine-based binder.
12 . The electrode of claim 10 , wherein the interlayer further comprises a carbon-based conductive material.
13 . The electrode of claim 1 , wherein the binder is a dry binder, wherein the dry binder comprises a fibrillized binder, and the dry binder comprises a fluorine-based binder.
14 . The electrode of claim 1 , wherein the electrode active material layer further comprises a conductive material, wherein the conductive material is a dry conductive material, wherein the dry conductive material comprises a carbon-based conductive material.
15 . The electrode of claim 1 , wherein the electrode active material layer is a self-standing film, and the electrode active material layer is free of residual processing solvent.
16 . The electrode of claim 1 , wherein a change rate of a vertical relative force (FVR) as a function of depth, of the electrode active material layer, from a first point to a second point, is 300% or less, when measured by a surface and interfacial cutting analysis system (SAICAS), wherein with respect to a total thickness of the electrode active material layer, the first point is spaced apart by 5% from a surface of the electrode active material layer in a direction of the electrode current collector and the second point is spaced apart by 5% from a surface of the electrode current collector.
17 . The electrode of claim 1 , wherein a horizontal force ratio of a second horizontal force (F H2 ) at a second point to a first horizontal force (F H1 ) at a first point in the electrode active material layer is 50% or more, when measured by a surface and interfacial cutting analysis system (SAICAS), wherein, with respect to a total thickness of the electrode active material layer, the first point is spaced apart by 10% from a surface of the electrode active material layer in a direction of the electrode current collector and the second point is spaced apart by 10% from a surface of the electrode current collector.
18 . A lithium battery, comprising: a cathode; an anode; and an electrolyte between the cathode and the anode, wherein at least one of the cathode or the anode is the electrode according to claim 1 .
19 . A method of preparing an electrode, the method comprising: preparing a mixture by dry mixing a dry electrode active material, a dry conductive material, and a dry binder; providing an electrode current collector; preparing the electrode comprising an electrode active material layer and a binder on one side or opposite sides of the electrode current collector, by placing and rolling the mixture on the one side or the opposite sides of the electrode current collector; and introducing a plurality of through-holes into the electrode active material layer, wherein the introduction of the plurality of through-holes is carried out at the same time as the rolling, or subsequent to the rolling; wherein the electrode current collector is at a portion of the electrode active material layer on one side of the electrode active material layer or at a portion of the electrode active material layer between opposing sides of the electrode active material layer; wherein the electrode has: a first domain comprising the portion of the electrode active material layer and the electrode current collector; and a second domain comprising a remaining portion of the electrode active material layer and being free of the electrode current collector, and wherein the plurality of through-holes is in the second domain and the first domain is free of any through-hole of the plurality of through-holes.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0099439, filed on Jul. 28, 2021, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. BACKGROUND 1. Field One or more embodiments of the present disclosure are related to an electrode, a lithium battery employing the same, and a method of preparing the same. 2. Description of the Related Art As various devices are increasingly miniaturized and have higher performance, it has become important for lithium batteries to have higher energy density as well as miniaturization and weight reduction. That is, lithium batteries having high capacity have become increasingly important. In addition, as various wearable devices appear in the market, lithium batteries with increased flexibility have become increasingly important. To realize lithium batteries suitable for such uses, electrodes having flexibility as well as high loading capacity are being studied. In an electrode with high loading capacity, the distribution of constituent components inside the electrode may become non-uniform and density near the electrode surface may increase. Accordingly, performance of a lithium battery employing such an electrode may decrease. In this context, there is a need for an electrode capable of preventing or reducing a decrease in performance in lithium batteries and having flexibility. SUMMARY Aspect of one or more embodiments of the present disclosure are directed towards a novel electrode capable of preventing or reducing performance degradation in a battery by having substantially uniform distribution of constituent components inside the electrode. In addition, aspects of one or more embodiments are directed towards a novel electrode capable of preventing or reducing performance degradation in a battery and increasing flexibility of the battery by including an electrode current collector positioned in a part of the electrode, and including through-holes in an electrode active material layer. Further aspects of one or more embodiments are directed towards a lithium battery including the electrode. Further aspects of one or more embodiments are directed towards a preparation method of the electrode. Additional aspects will be set forth in part in the description that follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure. According to one or more embodiments of the present disclosure, an electrode includes: an electrode active material layer containing an electrode active material and a binder; and an electrode current collector at a portion of the electrode active material layer on (or at) one side of the electrode active material layer, or at a portion of the electrode active material layer between opposing sides of the electrode active material layer, wherein the electrode active material layer includes a plurality of through-holes. According to one or more embodiments of the present disclosure, a lithium battery includes: a cathode; an anode; and an electrolyte between the cathode and the anode, wherein at least one of the cathode or the anode is the electrode described above. According to one or more embodiments of the present disclosure, an electrode preparation method includes: preparing a mixture by dry mixing an electrode active material, a dry conductive material, and a dry binder; providing an electrode current collector; preparing an electrode including an electrode active material layer on one side or opposite sides (sides facing opposite each other) of the electrode current collector, by placing and rolling the mixture on the one side or opposite sides of the electrode current collector; and introducing a plurality of through-holes into the electrode active material layer, wherein the introduction of the plurality of through-holes is carried out concurrently with (e.g., at the same time as) the rolling, or subsequent to the rolling. BRIEF DESCRIPTION OF THE DRAWINGS The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: FIGS. 1A-1B are cross-sectional views of an electrode according to one or more embodiments of the present disclosure. FIGS. 2A-2B are cross-sectional views of an electrode according to one or more embodiments of the present disclosure. FIGS. 3A-3C are cross-sectional views of an electrode according to the related art. FIG. 4 is a schematic perspective view of an electrode according to one or more embodiments of the present disclosure. FIG. 5 is a schematic perspective view of an electrode according to one or more embodiments of the present disclosure. FIGS. 6A-6F are plan views of an electrode according to one or more embodiments of the present disclosure. FIG. 7 is