Patent Application
20220200106
The present invention relates to an electrode assembly having a depression portion formed in an electrode tab, a guide member configured to stack the same, and a stacked type battery manufacturing method using the same. More particularly, the present invention relates to an electrode assembly including a plurality of electrode sheets having outwardly protruding electrode tabs and a separator interposed between the plurality of electrode sheets, wherein a depressed portion is inwardly formed in at least one of three surfaces of each rectangular electrode tab protruding outwards from the electrode assembly, a guide member configured to stack the same, and a stacked type battery manufacturing method using the same.
With the technological development of mobile devices and an increase in the demand therefor, the demand for secondary batteries as energy sources has sharply increased. Among such secondary batteries is a lithium secondary battery having a high energy density and a high discharge voltage, into which much research has been carried out and which has also been commercialized and widely used.
An electrode assembly, which is mounted in a battery case, is a power generating element that has a structure in which a positive electrode, a separator, and a negative electrode are stacked and that can be charged and discharged. The electrode assembly is classified as a jelly-roll type electrode assembly, which is configured to have a structure in which a long sheet type positive electrode and a long sheet type negative electrode, to which active materials are applied, are wound in the state in which a separator is disposed between the positive electrode and the negative electrode, a stacked type electrode assembly, which is configured to have a structure in which a plurality of positive electrodes having a predetermined size and a plurality of negative electrodes having a predetermined size are sequentially stacked in the state in which separators are disposed respectively between the positive electrodes and the negative electrodes, or a stacked/folded type electrode assembly, which is configured to have a structure in which unit cells, such as full cells or bi-cells, are wound using a separation film. Thereamong, the stacked type electrode assembly has an advantage in that it is possible to easily obtain various forms of electrodes.
Also, in the case in which a further alignment process is added to prevent movement of the electrode assemblies 100 in order to solve the above problem, a manufacturing process is complicated, and it is difficult to prevent shaking of the electrode assemblies after alignment, whereby the alignment effect does not seem to be great. In connection therewith, Patent Document 1 simplifies a manufacturing process by fitting an electrode tab having a hole formed therein between a flat plate and a guide member located vertically above the plate so as to be spaced apart from the plate, the guide member having two bars formed thereon and overcomes a phenomenon in which electrode tabs are pushed at the time of stacking. When the guide member having the two bars is separated from an electrode assembly, however, the stacked electrode tabs may move. In addition, a predetermined portion of the electrode tab having the simple hole is fixed, but not the entirety of the electrode tab is fixed so as not to move in all directions, i.e. an upward direction, a downward direction, a leftward direction, and a rightward direction. Furthermore, a predetermined gap is generated from the bars due to the characteristics of a circular shape, and complete fixing is not achieved due to such a gap.
Patent Document 2 discloses a positioning opening used for positioning at the time of assembly, wherein the positioning opening is configured to be easily removed after stacking using a guide pin, whereby a phenomenon in which electrode tabs are pushed at the time of stacking is overcome. In this case, however, fixing of an electrode assembly, which may move in all directions, i.e. an upward direction, a downward direction, a leftward direction, and a rightward direction, is not considered.
In the case of the stacked type electrode assembly, as described above, stacking is complicated and troublesome, and it is necessary to maintain the fixed state thereof even after stacking. Therefore, there is a need for an electrode assembly configured to be fixed such that the electrode assembly does not move in all directions while an electrode assembly stacking process is simplified, a guide member therefor, and a stacking method thereof.
(Patent Document 1) Korean Patent Application Publication No. 2019-0041852 (2019.04.23)
(Patent Document 2) Japanese Patent Application Publication No. 2002-270242 (2002.09.20)
The present invention has been made in view of the above problems, and it is an object of the present invention to provide an electrode assembly including a plurality of electrode sheets having outwardly protruding electrode tabs and a separator interposed between the plurality of electrode sheets, wherein a depressed portion is inwardly formed in at least one of three surfaces of each rectangular electrode tab protruding outwards from the electrode assembly, a guide member configured to stack the same, and a stacked type battery manufacturing method using the same.
In order to accomplish the above object, the present invention provides an electrode assembly including a plurality of electrode sheets having outwardly protruding electrode tabs and a separator interposed between the plurality of electrode sheets, wherein each of the electrode tabs has a hexahedral shape, and a depressed portion is inwardly formed in at least one of three surfaces of each electrode tab excluding a surface completely contacting the electrode assembly, among side surfaces of the electrode tab perpendicular to a stacking plane of the electrode tabs.
The depressed portion may be formed in an edge abutting each of the three surfaces of the electrode tab, may be formed through the electrode tab without abutting each of the three surfaces of the electrode tab, or may be simultaneously formed in the inner surface and the edge of the electrode tab.
In addition, the depressed portion may be formed in at least one of the three surfaces of the electrode tab in a triangular shape, a concavo-convex shape, a serrated shape, a semicircular shape, or a half-elliptical shape. Alternatively, the shape of the depression portion may consist of a curved line and/or a straight line alone.
In addition, the depressed portions may be formed in respective surfaces of the electrode tab perpendicular to the electrode assembly, and the depressed portions may be symmetric to each other.
The depressed portion may be configured so as to have a shape capable of forming one or more catching portions in the electrode tab.
In addition, the present invention provides an electrode assembly stacking guide member configured to correspond to a plurality of electrode assemblies having formed therein the depressed portions, wherein the electrode assembly stacking guide member is configured to enable the electrode assemblies to be stacked while being aligned.
The electrode assembly stacking guide member may include a flat plate and moving members configured to be movable in an upward-downward direction and/or in a leftward-rightward direction depending on the shape of the electrode tabs.
In addition, the present invention provides a stacked type battery manufacturing method including (1) preparing a plurality of electrode sheets, each of the electrode sheets including electrode tabs having depressed portions, (2) stacking the electrode sheets and a separator to manufacture an electrode assembly, (3) fitting the guide member on the electrode tabs of the electrode assembly to align the electrode assembly, and (4) fixing the electrode assembly and removing the guide member.
In addition, in step (3), the guide member may fix the electrode assembly so as not to move in dx, dy, and dθ directions based on the electrode tabs.
In addition, in step (4), the guide member may be separated leftwards and rightwards.
In addition, in step (4), the moving members of the guide member may be separated and moved from the flat plate at the lower end thereof so as to be removed from the electrode assembly after fixing of the electrode assembly.
In the present invention, one or more constructions that do not conflict with each other may be selected and combined from among the above constructions.
Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings such that the preferred embodiments of the present invention can be easily implemented by a person having ordinary skill in the art to which the present invention pertains. In describing the principle of operation of the preferred embodiments of the present invention in detail, however, a detailed description of known functions and configurations incorporated herein will be omitted when the same may obscure the subject matter of the present invention.
In addition, the same reference numbers will be used throughout the drawings to refer to parts that perform similar functions or operations. In the case in which one part is said to be connected to another part in the specification, not only may the one part be directly connected to the other part, but also, the one part may be indirectly connected to the other part via a further part. In addition, that a certain element is included does not mean that other elements are excluded, but means that such elements may be further included unless mentioned otherwise.
Hereinafter, the present invention will be described with reference to the following embodiments. These embodiments are provided only for easier understanding of the present invention and should not be construed as limiting the scope of the present invention.
Embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The present invention provides an electrode assembly including a plurality of electrode sheets having outwardly protruding electrode tabs and a separator interposed between the plurality of electrode sheets, wherein each of the electrode tabs has a hexahedral shape, and a depressed portion is inwardly formed in at least one of three surfaces of each electrode tab.
Any one of three surfaces of the rectangular electrode tab means any one of three surfaces of the rectangular electrode tab excluding the surface completely contacting the electrode assembly, among side surfaces of the electrode tab perpendicular to a stacking plane of the electrode tabs.
That is, when viewed from the three surfaces, one or more electrode tabs are shown as being stacked.
The depressed portion may be formed in an edge abutting each of the three surfaces of the electrode tab, may be formed through the electrode tab without abutting each of the three surfaces of the electrode tab, or may be simultaneously formed in the inner surface and the edge of the electrode tab.
In addition, the depressed portion may be formed in at least one of the three surfaces of the electrode tab in a triangular shape, a concavo-convex shape, a serrated shape, a semicircular shape, or a half-elliptical shape. Alternatively, the shape of the depression portion may consist of a curved line and/or a straight line alone.
The three surfaces of the electrode tab are the surfaces of the electrode tabs that do not contact a body of the electrode assembly. At this time, the depressed portion may be formed in only one of the three surfaces of the electrode tab, may be formed in each of the three surfaces of the electrode tab, or may be formed in each of the two surfaces opposite each other, among the three surfaces of the electrode tab.
Specifically,
Referring to
The electrode assembly 100 may be easily fixed through the electrode tabs 200 having the depressed portions 210 described above, whereby concern about short circuit due to shaking of the electrode assembly is reduced even in the case in which a positive electrode and a negative electrode are formed so as to have the same size.
Instead of a conventional structure in which the size of the positive electrode is designed so as to be less than the size of the negative electrode as the result of concern about short circuit of the electrode assembly 100, the structure according to the present invention is adopted for the electrode tab, whereby it is possible to manufacture a battery based on a design in which the positive electrode and the negative electrode have the same size. As a result, the capacity of a stacked type battery having the electrode tab according to the present invention is increased, compared to a conventional stacked type battery.
In electrode tabs according to the present invention, as shown in
In electrode tabs according to the present invention, as shown in
In the electrode assembly 100 according to the fourth embodiment of the present invention, as shown in
As in the fifth embodiment of
As shown in
In addition to the guide members 300 disposed at opposite sides of the electrode tabs to fix the electrode assembly, a separate guide member 310 may be inserted into the depressed portion 260 to fix the electrode assembly. The guide member 310, which is formed so as to correspond to the shape of the depressed portion 260 formed in the interior of each of the electrode tabs, may be configured to move upwards and downwards. At the time of stacking of electrode assemblies 100, the guide member 310 may be inserted into the depressed portions 260, and may then be removed after stacking.
As in the seventh embodiment of
In addition, the guide members 300 or 310 of the present invention may be disposed at opposite sides of the electrode tabs protruding from the electrode assembly 100 and between the electrode tabs, or may be inserted into the depressed portions 270 located in the electrode tabs.
The present invention may provide an electrode assembly stacking guide member configured to correspond to a plurality of electrode assemblies having formed therein the depressed portions according to the above description and configured to enable the electrode assemblies to be stacked while being aligned. The electrode assembly stacking guide member may include a flat plate and moving members configured to be movable in an upward-downward direction and/or in a leftward-rightward direction depending on the shape of the electrode tabs.
The guide member 300 according to the present invention may have moving members 320 having a shape corresponding electrode assemblies to be stacked before the electrode assemblies are stacked, as shown in
Alternatively, the moving members 320 may be inserted into a predetermined space provided in the plate of the guide member 300 such that the electrode assemblies can be easily separated from the guide member. The moving members 320 may be inserted so as to move downwards by the same height of the plate of the guide member 300 or to move downwards lower than the plate such that the electrode assemblies 100 are easily separated. Insertion of the moving members 320 may be performed by dynamic operation based on external force, or may be performed by electrical operation based on system. In the case in which the shape of each of the electrode tabs is a shape capable of removing the guide member 300 in one direction, as in the first embodiment, it is possible to remove only the electrode assemblies 100 in the state in which the moving members 320 are fixed.
The present invention provides a stacked type battery manufacturing method including preparing a plurality of electrode sheets, each of the electrode sheets including electrode tabs having the depressed portions described above, stacking the electrode sheets and a separator to manufacture an electrode assembly, and fitting a guide member having a shape corresponding to the electrode tabs on the electrode tabs of the electrode assembly to align the electrode assembly. At this time, the electrode assembly manufacturing process and the electrode assembly alignment process may be integrated to provide a method of manufacturing the electrode assembly by fitting the electrode tabs in the guide member and stacking the separator at the time of manufacture of the electrode assembly. In addition, the guide member may fix the electrode tabs of the electrode assembly so as not to move in the dx, dy, and dθ directions, whereby the electrode assemblies may be stacked such that arrangements of positive electrodes and negative electrodes of the electrode assemblies in the stacking direction coincide with each other. Subsequently, the electrode assemblies are aligned, and then the guide member is removed. The manner in which the guide member is removed may be changed depending on the shape of each of the electrode tabs.
Although the specific details of the present invention have been described in detail, those skilled in the art will appreciate that the detailed description thereof discloses only preferred embodiments of the present invention and thus does not limit the scope of the present invention. Accordingly, those skilled in the art will appreciate that various changes and modifications are possible, without departing from the category and the technical idea of the present invention, and it will be obvious that such changes and modifications fall within the scope of the appended claims.
As is apparent from the above description, the present invention, which relates to an electrode assembly having a depression portion formed in an electrode tab, a guide member configured to stack the same, and a stacked type battery manufacturing method using the same, has advantages in that it is possible to reduce a phenomenon in which stacked electrodes are pushed, whereby it is possible to more accurately and conveniently locate the electrodes or unit cells in position thus to simplify the stacked type battery manufacturing method.
In addition, it is not necessary to design the size of a positive electrode so as to be less than the size of a negative electrode in order to prevent short circuit of the electrode assembly, whereby it is possible to increase the capacity of a battery.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2019-0119975 | Sep 2019 | KR | national |
This application is a national phase entry under 35 U.S.C. § 371 of PCT/KR2020/012702 filed on Sep. 21, 2020 and claims the benefit of priority to Korean Patent Application No. 2019-0119975 filed on Sep. 27, 2019, the disclosures of which are each hereby incorporated by reference herein its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2020/012702 | 9/21/2020 | WO | 00 |
