KR20230053861A - Electrode assembly body for lithium secondary battery - Google Patents

Abstract

An electrode assembly for a lithium secondary battery according to an embodiment of the present invention includes: a positive electrode body; and a negative electrode body positioned on either the upper or lower side of the positive electrode body, wherein the positive electrode body is provided in a form in which the upper and lower surfaces and the thickness surface are surrounded by a first separator, a second separator and an insulating member, and one end or a part of each of the positive electrode body and the negative electrode body can be provided in a folded form in a zigzag shape while alternating up and down with each other.

Description

Electrode assembly for lithium secondary battery {ELECTRODE ASSEMBLY BODY FOR LITHIUM SECONDARY BATTERY}

The present invention relates to an electrode assembly for a lithium secondary battery and a manufacturing method thereof, and more particularly, to an electrode assembly for a lithium secondary battery capable of maximizing the capacity of a lithium secondary battery and simplifying a process, and a manufacturing method thereof.

Recently, with the development of the high-tech electronics industry, it is possible to reduce the size and weight of electronic equipment, and thus the use of portable electronic devices and various types of mobile devices is increasing. As the need for a battery having a high energy density as a power source for such portable electronic devices and mobile devices increases, research on lithium secondary batteries is being actively conducted.

In particular, rapid thinning and miniaturization of electronic devices and mobile devices is rapidly expanding the demand for thin lithium secondary batteries, while the structure and / or manufacturing method of existing cylindrical or prismatic lithium secondary batteries There is a limit that it is not excellent in terms of energy density per volume according to . Therefore, when a thin battery having a thickness of 5 mm or less is used for high-performance portable electronic devices such as mobile phones, camcorders, and notebook computers, and mobile devices, it is difficult to obtain sufficient driving time.

Specifically, the prismatic lithium secondary battery has poor battery efficiency in terms of volume due to the jelly roll-shaped electrode body structure, and due to technical limitations on reducing the wall thickness of a metal packaging material manufactured by low-temperature elongation, the battery thickness is decreases and the energy density decreases.

On the other hand, in the case of a pouch-type lithium secondary battery formed by sealing the stacked electrode assemblies with an aluminum laminate packaging material, the waste of space caused by the jelly roll can be reduced, but the internal space of the battery is consumed due to the uncoated portion of the electrode As a result, there is a problem in that the capacity of the battery is lost. That is, the uncoated portion of the electrode to which the active material is not applied protrudes from the electrode, and the uncoated portion is also accommodated in the pouch, but the space accommodating the uncoated portion becomes a wasted space.

Referring to FIG. 1, a lithium secondary battery 1 including an electrode assembly 10 according to the present invention includes a pouch-type battery case 101 and an electrode assembly 10 accommodated inside the battery case 101. can include

The battery case 101 is preferably a pouch made of a flexible material. In addition, the battery case 101 may accommodate the electrode assembly 10 and may be sealed or sealed so that portions of the positive and negative electrode tabs 210 and 310, that is, terminals are exposed. As shown in FIG. 1 , the battery case 101 may include an upper pouch 102 and a lower pouch 103 . A cup portion 105 is formed in the lower pouch 103 to provide an accommodation space 104 capable of accommodating the electrode assembly 10, and the upper pouch 102 has the electrode assembly 10 in the battery case 101. The receiving space 104 is covered from the top so as not to escape to the outside. In FIG. 1 , the cup portion 105 is illustrated as being formed only on the lower pouch 103 , but is not limited thereto and may be formed in various ways such as being formed on the upper pouch 102 . The upper pouch 102 and the lower pouch 103 may be manufactured by connecting one side to each other as shown in FIG. 1 , but are not limited thereto and may be manufactured in various ways such as being separated from each other and separately manufactured.

Referring to FIG. 1 , positive electrode tabs and negative electrode tabs 210 and 310 are connected to uncoated portions (not shown) of the electrode assembly 10, respectively, and insulating parts 220 and 320 are formed on portions of the positive and negative electrode tabs 210 and 310. The electrode assembly 10 is accommodated in the accommodating space 104 provided in the cup portion 105 of the lower pouch 103, and the upper pouch 102 covers the accommodating space 104 from the top. In addition, the electrolyte solution may be injected into the inside of the pouch 102 and the sealing portion formed on the edges of the lower pouch 103 may be sealed.

The electrolyte solution is for moving lithium ions generated by the electrochemical reaction of the electrode during charging and discharging of the lithium secondary battery 1, and uses a non-aqueous organic electrolyte solution or polymer electrolyte that is a mixture of lithium salt and high-purity organic solvents. May contain polymers. Through this method, the pouch type lithium secondary battery 1 can be manufactured.

By the way, in the case of the anode body in the form of surrounding the anode using a polymer insulating film and a separator used in the above-described stack type electrode assembly 10, it is easy to stack and align with the cathode body, but the anode body The capacity of the battery may be reduced due to the polymer insulating film surrounding the positive electrode along the thickness direction of the battery.

In addition, in a state in which a plurality of positive electrodes and a plurality of negative electrodes are stacked, the uncoated regions of the positive electrodes are gathered together, and the uncoated regions of the negative electrodes are gathered together, and then the electrode tabs are welded. This process complicates the process and lowers productivity.

The present applicant has proposed the present invention in order to solve the above problems.

Korean Registered Patent No. 10-1168651 (Registration Notice 2012.07.25.)

Provided is an electrode assembly for a lithium secondary battery capable of improving or improving the capacity of a lithium secondary battery and a manufacturing method thereof.

The present invention provides an electrode assembly for a lithium secondary battery and a method for manufacturing the same, which can reduce the waste of an insulating member surrounding the positive electrode and increase the area or size of the positive electrode by the same amount as the reduced area of the insulating member.

The present invention provides an electrode assembly for a lithium secondary battery and a method for manufacturing the same, which can simplify the production process and increase productivity since there is no need to weld electrode tabs to the uncoated portion of the positive electrode and the uncoated portion of the negative electrode in a state where a plurality of them are stacked. do.

An electrode assembly for a lithium secondary battery according to an embodiment of the present invention for achieving the above object includes a cathode body; And a cathode body positioned on one of the upper and lower sides of the anode body, wherein the anode body is provided in a form in which upper and lower surfaces and thickness surfaces are surrounded by a first separator, a second separator and an insulating member, One end or part of each of the anode body and the cathode body may be provided in a folded form in a zigzag shape in a state of alternating up and down with each other.

The anode body, the anode; A cathode active material coated or coated on at least one of the upper and lower surfaces of the cathode; The first separator on which the positive electrode coated or coated with the positive electrode active material is placed; The insulating member formed on the upper surface of the first separator to surround the cathode active material and the thickness surface of the cathode; and the second separator bonded to the upper surface of the insulating member to cover the positive electrode active material and the positive electrode, and an anode incision portion in which the positive electrode and the positive electrode active material do not exist is formed between the positive electrode active materials adjacent to each other. can

A portion corresponding to the anode cutout may be formed in the first separator and the second separator.

The positive electrode body may include a positive electrode uncoated portion in which the positive electrode active material does not exist, and a positive electrode tab may be connected to the positive electrode uncoated portion.

The insulating member may be formed to surround a thickness surface of the positive electrode and the positive electrode active material so that only the positive electrode tab is exposed.

The negative electrode body includes a negative electrode and a negative electrode active material coated or coated on at least one of upper and lower surfaces of the negative electrode, and negative electrode cutouts are formed in the negative electrode and the negative electrode active material at regular intervals along the longitudinal direction of the negative electrode. can

The negative electrode body may include an anode uncoated portion in which the anode active material is not present in the anode, and a negative electrode tab may be connected to the anode uncoated portion.

The anode body and the cathode body may be alternately folded in a zigzag shape in a state where the anode cutout part and the cathode cutout part are sandwiched with each other so that one end or part thereof alternately alternates up and down.

The anode body and the cathode body may be alternately folded in a zigzag shape by the anode cutout and the cathode cutout.

The anode body includes a bridge anode blank portion positioned at one end of the anode cutout portion, and the cathode body includes a bridge cathode blank portion positioned at one end of the cathode cutout portion, a state in which the anode cutout portion and the cathode cutout portion are inserted into each other The anode uncoated portion of the bridge and the cathode uncoated portion of the bridge facing each other may be folded in the same direction.

In the anode body, the first separator, the second separator, and the insulating member may be folded in a zigzag shape in the same manner as the anode.

Since the electrode assembly for a lithium secondary battery and the manufacturing method according to the present invention can minimize the size or width of the insulating member surrounding the thickness surface of the positive electrode, the capacity of the lithium secondary battery including the positive electrode body increases as the size of the positive electrode increases. can be improved or improved. Because, instead of punching out the insulating member surrounding the thickness surface of the anode, the insulating member can be printed on the separator, so it is possible to surround the thickness surface of the anode with the insulating member even if the amount or size of the insulating member is reduced.

Since the electrode assembly for a lithium secondary battery according to the present invention has a form in which the positive and negative electrodes are folded in a zigzag shape, the positive and negative electrodes constituting the electrode assembly have one current path connected to each other, so that a blank is required to weld the electrode tab. It is not necessary to gather them together and weld the electrode tabs to them, and the electrode tabs can be welded to either the upper or lower surfaces of the anode body and the cathode body. Due to this, the process of welding the electrode tab can be simplified and productivity can be increased.

The electrode assembly for a lithium secondary battery according to the present invention and its manufacturing method can maximize the opposing area of a positive electrode and a negative electrode while having a Z-folding structure because the positive electrode incision and the negative electrode incision are zigzag-folded in a state of being sandwiched with each other, and such an electrode The capacity of the lithium secondary battery including the assembly can be increased.

1 is a perspective view showing a lithium secondary battery including an electrode assembly according to the prior art.
2 to 4 are diagrams showing a cathode body used in an electrode assembly for a lithium secondary battery according to an embodiment of the present invention.
5 to 7 are views showing an anode body used in an electrode assembly for a lithium secondary battery according to an embodiment of the present invention.
8 is a cross-sectional view of a positive electrode body and a negative electrode body of an electrode assembly for a lithium secondary battery according to an embodiment of the present invention.
9 is a view for explaining a process of manufacturing an electrode assembly by Z-folding a positive electrode body and a negative electrode body of an electrode assembly for a lithium secondary battery according to an embodiment of the present invention.
10 is a view showing another form of a positive electrode body and a negative electrode body used in an electrode assembly for a lithium secondary battery according to an embodiment of the present invention.

Advantages and/or features of the present invention, and methods of achieving them, will become apparent with reference to the following detailed description of the embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various forms different from each other, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

In addition, preferred embodiments of the present invention to be carried out below are provided in each system functional configuration in order to efficiently explain the technical components constituting the present invention, or system functions commonly provided in the technical field to which the present invention belongs. The configuration is omitted as much as possible, and the functional configuration that should be additionally provided for the present invention will be mainly described. If one of ordinary skill in the art to which the present invention pertains, one will be able to easily understand the functions of conventionally used components among the omitted functional configurations not shown below, and also the omitted configurations as described above. The relationship between elements and components added for the present invention will also be clearly understood.

In addition, in the following description, "transmission", "communication", "transmission", "reception" and other similar terms of signals or information refer to direct transmission of signals or information from one component to another. as well as passing through other components. In particular, "transmitting" or "transmitting" a signal or information as a component indicates the final destination of the signal or information, and does not mean a direct destination. The same is true for "reception" of signals or information.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 to 4 are views showing a positive electrode body used in an electrode assembly for a lithium secondary battery according to an embodiment of the present invention, and FIGS. 5 to 7 are used in an electrode assembly for a lithium secondary battery according to an embodiment of the present invention. Figure 8 is a view showing a cross-section of a positive electrode body and a negative electrode body of an electrode assembly for a lithium secondary battery according to an embodiment of the present invention, Figure 9 is a lithium secondary battery according to an embodiment of the present invention A view for explaining a process of manufacturing an electrode assembly by Z-folding the positive and negative electrode bodies of the battery electrode assembly, FIG. It is a drawing showing another form.

The electrode assembly 110 for a lithium secondary battery and its manufacturing method according to an embodiment of the present invention described below are used for a lithium secondary battery, and a pouch type lithium secondary battery will be described as an example, but limited thereto. it is not going to be

Hereinafter, the electrode assembly 100 for a lithium secondary battery and the manufacturing method of the electrode assembly 100 according to an embodiment of the present invention will be described in detail with reference to the drawings. For reference, since the electrode assembly 100 for a lithium secondary battery according to an embodiment of the present invention describes a lithium secondary battery accommodated in the battery case 101 shown in FIG. 1, the electrode assembly 100 for a lithium secondary battery Excluding parts are the same as in the case of FIG. 1, so repetitive descriptions are omitted.

Unlike the electrode assembly 10 shown in FIG. 1, the electrode assembly for a lithium secondary battery (100, hereinafter referred to as "electrode assembly") according to an embodiment of the present invention described below includes several sheets of positive electrode and several sheets of negative electrode. Instead of having a structure in which bodies are alternately stacked, one anode body and one cathode body have a zigzag-folded structure (Z-folding).

2 to 9, the electrode assembly (100, see FIG. 9) according to an embodiment of the present invention includes an anode body 110; and a cathode body 140 positioned on one of the upper and lower sides of the anode body 110, wherein the anode body 110 includes a first separator 160, a second separator 160 and an insulating member. It is provided in a form in which the upper and lower surfaces and the thickness surface are surrounded by 170, and one end or part of each of the anode body 110 and the cathode body 140 is folded in a zigzag form in a state of alternating up and down with each other. can be provided with

Referring to FIG. 9 , the electrode assembly 100 according to an embodiment of the present invention has a structure in which an anode body 110 and a cathode body 140 are alternately folded, that is, in a zigzag shape. 110) and one sheet of cathode body 140 are placed vertically and folded in a zigzag form, there is a risk of short circuit because a part in direct contact with the same polarities occurs. In the electrode assembly 100 according to an embodiment of the present invention, the positive electrode body 110 and the negative electrode body 140 are folded before folding one sheet of the positive electrode body 110 and one sheet of the negative electrode body 140 in a zigzag shape. Since parts are arranged to be positioned alternately up and down, when folded in a zigzag form, direct contact between the same polarities (in particular, between cathodes) does not occur.

2 to 4, the structure and manufacturing method of the anode body 110 of the electrode assembly 100 according to an embodiment of the present invention will be described.

As shown in FIG. 2 , the positive electrode body 110 may include a positive electrode 111 and a positive electrode active material 113 coated or coated on at least one of an upper surface or a lower surface of the positive electrode 111 . Referring to FIG. 2(a) , a positive electrode active material 113 may be coated or coated in a long strip shape on the surface of a sheet-shaped positive electrode 111 . The cathode active material 113 may be formed as a pattern coating in a band shape on surfaces (upper and lower surfaces) of the cathode 111 .

Here, the positive electrode 111 is a cathode current collector.

It is preferable that the positive active material 113 is not formed on the entire surface of the positive electrode 111, but formed on the upper and lower surfaces of the positive electrode 111 in a band shape at regular intervals. The surface of the positive electrode 111 is exposed in the gap between the positive electrode active materials 113 . Here, the portion 112 located between the positive electrode active materials 113 of the positive electrode 111 becomes a bridge positive electrode uncoated portion 112 to be described later.

In addition, at least one of both ends of the positive electrode 111 may be formed with a positive electrode uncoated portion 111C in which the positive electrode active material 113 is not present. Here, the positive electrode uncoated portion 111C in which the positive electrode active material 113 is not formed is formed with a larger width than the bridge anode uncoated portion 112 . That is, the width of the positive electrode uncoated portion 111C is almost similar to that of the strip-shaped positive electrode active material 113, but the width of the bridge anode uncoated portion 112 should be smaller than that of the positive electrode active material 113. Because, since the anode non-coated portion 111C is a portion for connecting or welding the anode tab 210, a sufficient size must be secured, whereas the anode non-coated portion 112 of the bridge does not contribute to the reaction of the electrode and simply functions as a connection. Since it is a part that does, it does not need to be formed large. If the bridge anode non-coated portion 112 is formed with a large width, the size of the electrode assembly 100 increases, but the capacity of the battery does not increase that much. Here, the bridge anode uncoated portion 112 is a folded portion when the anode body 110 is folded in a zigzag shape.

Meanwhile, the positive electrode active material 113 is coated or coated on the upper and lower surfaces of the positive electrode 111, and in the case of the positive electrode non-coated portion 111C, the positive electrode active material 113 does not exist on the upper and lower surfaces of the positive electrode 111.

The positive electrode body 110 of the electrode assembly 100 according to an embodiment of the present invention, as shown in FIG. 111) may be manufactured by punching or cutting along the cutting line CL1 of FIG. 2(b).

Referring to FIG. 2(b) , the cutting line CL1 may be formed to include a cathode uncoated portion 111C and a cathode active material 113 positioned at either end of both ends of the cathode 111 in the width direction. The cutting line CL1 may be formed along the disposition direction of the strip-shaped positive electrode active material 113, that is, along the width direction of the positive electrode 111, while leaving only a portion of the bridge positive electrode uncoated portion 112. According to this method, several sheets (pieces) of anode body 110 can be manufactured for one sheet of cathode 111 . In the case of FIG. 2(b), seven (pcs) anode bodies 110 can be obtained.

Meanwhile, the positive electrode body 110 of the electrode assembly 100 according to an embodiment of the present invention may be formed by pattern coating the positive electrode active material 113 in a strip shape, and as shown in FIG. 3, the positive electrode active material ( 113) may be formed by split coating.

Referring to FIG. 3(a) , a plurality of cathode active materials 113 having the same shape (rectangular shape or quadrangular shape) may be divided and formed on the surface (top and bottom surfaces) of the cathode 111 . Here, the positive electrode 111 corresponding to the gap between the positive electrode active materials 113 corresponds to the bridge positive electrode uncoated portion 112 of FIG. 2 . In addition, a positive electrode uncoated portion 111C in which the positive electrode active material 113 is not present may be formed at one end of both ends of the positive electrode 111 in the longitudinal direction. For reference, FIG. 3(b) is an enlarged view of a portion of FIG. 3(a).

The positive electrode body 110 may be obtained by punching or cutting the positive electrode 111 and the positive electrode active material 113 of FIG. 3 (b) along the cutting line CL1 of FIG. 3 (c). By punching or cutting along the cutting line CL1 of FIG. 3(c), the same anode body 110 as that of punching or cutting along the cutting line CL1 of FIG. 2(b) can be obtained.

Referring to FIG. 3(c), the cutting line CL1 includes a positive electrode non-coated portion 111C and a positive electrode active material 113 located at either end (top in the case of the drawing) of both ends in the longitudinal direction of the positive electrode 111. can be formed to The cutting line CL1 may be formed along the arrangement direction of the rectangular positive electrode active material 113, that is, along the longitudinal direction of the positive electrode 111, but leaving only a portion of the bridge positive electrode uncoated portion 112.

Meanwhile, the separator 160 should be positioned between the positive electrode body 110 and the negative electrode body 140 to be described later. In the case of the electrode assembly 100 according to an embodiment of the present invention, the positive electrode 111 and the separator 160 ) uses the anode body 110 formed like one unit. That is, it is characterized by using the pocketing anode body 110 to which the anode pocketing technology, which is a unique technology of the present applicant, is applied. Hereinafter, the anode body 110 means a pocketing anode body, and hereinafter, a process of manufacturing the pocketing anode body 110 will be described with reference to FIG. 4 .

By punching or cutting along the cutting line CL1 of FIGS. 2 (b) and 3 (c), the anode body 110 shown in FIG. 4 (a) is obtained. Referring to FIG. 4(a), the cathode body 110 is a bridge anode non-coated portion connecting a cathode non-coated portion 111C formed on one side, a cathode 111 on which a cathode active material 113 is formed, and a cathode active material 113. (112). At this time, the bridge anode uncoated portion 112 is formed on the lower side of the portion where the cathode active material 113 is formed, and the upper portion of the bridge anode uncoated portion 112 has an anode incision where the cathode 111 and the cathode active material 113 do not exist. A portion 114 is formed.

The positive electrode cutout 114 corresponds to a gap that separates adjacent positive electrode active materials 113 , that is, positive electrodes 111 in which the positive electrode active materials 113 are formed. Here, the cutting line CL1 is formed to coincide with the entire edge so that the anode incision 114, the bridge anode uncoated portion 112, the cathode active material 113, and the anode uncoated portion 111C can be simultaneously punched or cut. do.

In the case of the positive electrode body 110 shown in FIG. 4 (a), the portion of the positive electrode 111 on which the positive electrode active material 113 is formed and the positive electrode uncoated portion 111C are connected, and the positive electrode 111 on which the positive electrode active material 113 is formed ) is seven. Here, each positive electrode 111 on which the positive electrode active material 113 is formed corresponds to one positive electrode body in the prior art. However, in the case of the prior art, in order to electrically connect seven positive electrode bodies, a process of collecting the positive electrode uncoated portions formed on each anode body and welding the positive electrode tab to the positive electrode uncoated portions gathered together is required. On the other hand, in the case of the positive electrode body 110 shown in FIG. 4 (a), seven positive electrodes 111 on which the positive electrode active material 113 is formed and the positive electrode uncoated portion 111C are attached to the bridge anode uncoated portion 112. Since it is connected by a process, there is no need for a process of gathering the existing anode non-coated parts in one place. Instead, as shown in FIG. 4(b), by simply welding the positive electrode tab 210 to the positive electrode uncoated portion 111C, the positive electrode 111 including the positive electrode active material 113 and the bridge anode uncoated portion 112 The whole may be electrically connected to the positive electrode tab 210 .

In FIG. 4(b), reference numeral 220 denotes an insulator, and reference numeral 230 denotes a welded portion.

Meanwhile, as described above, the anode body 110 according to an embodiment of the present invention is a pocketing anode body in which the cathode 111 and the cathode active material 113 are surrounded by an insulating member 170 and a separator 160. am. 4(c) shows a diagram illustrating the pocketing anode body 110.

For reference, FIGS. 2 to 4 are plan views for explaining the anode body 110 .

Referring to FIG. 4(c), an insulating member 170 is formed along the entire edge of the positive electrode 111 including the positive electrode uncoated portion 111C, the positive electrode active material 113, and the bridge anode uncoated portion 112. . The insulating member 170 may be provided in a form surrounding the thickness surfaces of the positive electrode 111 and the positive electrode active material 113 . In addition, the first and second separators 160 are positioned on the lower and upper surfaces of the positive electrode 111 including the positive electrode uncoated portion 111C, the positive electrode active material 113, and the bridge anode uncoated portion 112, respectively. As described above, in the anode body 110 of the electrode assembly 100 according to an embodiment of the present invention, the lower and upper surfaces of the cathode 111 on which the cathode active material 113 is formed are the first and second separators 160 and since the thickness surface of the positive electrode active material 113 and the positive electrode 111 is surrounded by the insulating member 170, the positive electrode 111 and the positive electrode active material 113 are outside the separator 160 and the insulating member 170 not exposed That is, the anode body 110 is provided in the form of a pocketing anode body in which the cathode 111 and the cathode active material 113 are surrounded by the separator 160 and the insulating member 170 .

Referring to FIG. 4(c), the insulating member 170 shown by a thick solid line has the same shape as the cutting line CL1, and the thickness of the positive electrode 111 and the positive electrode active material 113 at the edge of the positive electrode 111. will surround

The first and second separators 160 are located on the lower and upper surfaces of the positive electrode 111 on which the positive electrode active material 113 is formed. In FIG. 4(c), the second separator 160 located on the upper surface of the positive electrode 111 ) is shown. In FIG. 4(c), the second separator 160 is a hatched portion.

In addition, the positive electrode tab 210 is also covered by the first and second separators 160, and in FIG. In order to explain, the positive electrode tab 210 is shown in a state not covered by the second separator 160 . While the anode 111 is surrounded by the insulating member 170 , the cathode tab 210 is not surrounded by the insulating member 170 and protrudes or is exposed outside the insulating member 170 . Since an external device (not shown) should be electrically connected to the positive electrode tab 210 , the positive electrode tab 210 is not surrounded by the insulating member 170 .

Fig. 8(a) is a cross-sectional view taken along the line A-A of Fig. 4(c). Referring to FIG. 8(a) , the positional relationship of the positive electrode body 111, the positive electrode active material 113, the first and second separators 160, the insulating member 170, and the positive electrode tab 210 can be seen.

Also, referring to FIG. 4(c), the anode cutout 114 is formed between the insulating members 170. That is, the gap (gap) between the insulating members 170 corresponds to the anode cutout 114 .

As described above, the anode body 110 of the electrode assembly 100 according to an embodiment of the present invention includes a cathode 111; A cathode active material 113 coated or coated on at least one of the upper and lower surfaces of the cathode 111; The first separator 160 on which the positive electrode 111 coated or coated with the positive electrode active material 113 is placed; The insulating member 170 formed on the upper surface of the first separator 160 to surround the thickness surface of the positive electrode active material 113 and the positive electrode 111; And the second separator 160 bonded to the top surface of the insulating member 170 to cover the cathode active material 113 and the cathode 111; and between the cathode active materials 113 adjacent to each other An anode cutout 114 in which the cathode 111 and the cathode active material 113 do not exist may be formed.

The anode cutout 114 is a portion in which the cathode 111, the cathode active material 113, the separator 160, and the insulating member 170 do not all exist. The anode cutout 114 is a part that functions similarly to a fastening groove for coupling the cathode body 140 and the anode body 110 together.

The anode body 110 according to an embodiment of the present invention is a pocketing anode body, wherein the insulating member 170 is first formed on the upper surface of the first separator 160 placed on the lower surface of the anode 111, and then the insulating member ( 170) may be manufactured by putting the anode body 110 of FIG. 4(b) in a pocketing space (not shown) and covering the upper surface of the anode 111 with the second separator 160.

The first separator and the second separator 160 are thermally bonded or bonded to the insulating member 170 to form a pocketing space. Here, the pocketing space is a space formed by being surrounded by the first and second separators 160 located on the upper and lower sides and the insulating member 170 located between the first and second separators 160, and the anode 111 means the space in which it is located.

The pocketing space is formed by attaching an insulating member 170 having the same shape as the edge of the anode 111 shown in FIG. 4 (a) to the upper surface of the first separator 160, or ) may be formed by printing an insulating member 170 on the upper surface of FIG. 4 (a) in the same shape as the edge of the anode 111. In the case of the anode body 110 of the electrode assembly 100 according to an embodiment of the present invention, since the pocketing space is formed by punching or printing the insulating member 170, waste of the insulating member 170 can be reduced. . In particular, when the pocketing space is formed by printing the insulating member 170 on the upper surface of the first separator 160, the bonding process between the first separator 160 and the insulating member 170 can be omitted. The production process of the sieve 110 can be simplified.

In the anode body 110 according to an embodiment of the present invention, not only the insulating member 170 but also the first separator and the second separator 160 located on the lower and upper surfaces of the insulating member 170 have anode cutouts 114 A part corresponding to may be formed.

Hereinafter, the cathode body 140 of the electrode assembly 100 according to an embodiment of the present invention will be described with reference to FIGS. 5 to 7 .

Referring to FIG. 5 , the negative electrode body 140 may include an anode 141 and an anode active material 143 coated or coated on at least one of an upper surface or a lower surface of the anode 141 . Referring to FIG. 5(a) , the negative electrode active material 143 may be coated or coated in a long strip shape on the surface of the sheet-shaped negative electrode 141 . The anode active material 143 may be formed as a pattern coating on the surface (upper and lower surfaces) of the anode 141 in a band shape.

Here, the negative electrode 141 is an anode current collector.

It is preferable that the negative active material 143 is not formed on the entire surface of the negative electrode 141, but formed on the upper and lower surfaces of the negative electrode 141 in a band shape at regular intervals. The surface of the negative electrode 141 is exposed in the gap between the negative electrode active materials 143 . Here, the portion 142 of the negative electrode 141 positioned between the negative electrode active materials 143 becomes a bridge negative electrode uncoated portion 142 to be described later.

In addition, at least one of both ends of the negative electrode 141 may be formed with a negative electrode uncoated portion 141C in which the negative electrode active material 143 is not present. Here, the negative electrode uncoated portion 141C where the anode active material 143 is not formed has a wider width than the bridge anode uncoated portion 142 . That is, the width of the negative electrode uncoated portion 141C is almost similar to that of the strip-shaped negative electrode active material 143, but the width of the bridge negative electrode uncoated portion 142 should be smaller than that of the negative electrode active material 143. This is because the negative electrode uncoated portion 141C is a portion for connecting or welding the anode tab 310, so a sufficient size must be secured, whereas the bridge anode uncoated portion 142 does not contribute to the reaction of the electrode and simply functions as a connection. Since it is a part that does, it does not need to be formed large. If the bridge cathode uncoated portion 142 is formed with a large width, the size of the electrode assembly 100 increases, but the capacity of the battery does not increase that much. Here, the bridge cathode uncoated portion 142 is a folded portion when the cathode body 140 is folded in a zigzag shape.

Meanwhile, the negative electrode active material 143 is coated or coated on the upper and lower surfaces of the negative electrode 141, and in the case of the negative electrode uncoated portion 141C, the negative electrode active material 143 does not exist on the upper and lower surfaces of the negative electrode 141.

The negative electrode body 140 of the electrode assembly 100 according to an embodiment of the present invention, as shown in FIG. 141) may be manufactured by punching or cutting along the cutting line CL2 of FIG. 5(b).

Referring to FIG. 5(b) , the cutting line CL2 may be formed to include the negative electrode non-coated portion 141C and the negative active material 143 located at either end of both ends of the negative electrode 141 in the width direction. The cutting line CL2 may be formed along the disposition direction of the strip-shaped negative electrode active material 143, that is, along the width direction of the negative electrode 141, while leaving only a portion of the bridge negative electrode uncoated portion 142. According to this method, several sheets (pieces) of negative electrode body 140 can be manufactured from one sheet of negative electrode 141 . In the case of FIG. 5( b ), 7 sheets (pieces) of cathode bodies 140 can be obtained.

On the other hand, the negative electrode body 140 of the electrode assembly 100 according to an embodiment of the present invention may be formed by pattern coating the negative electrode active material 143 in a strip shape, and as shown in FIG. 6, the negative electrode active material ( 143) may be formed by split coating.

Referring to FIG. 6(a) , a plurality of negative electrode active materials 143 may be divided and formed in the same shape (rectangular shape or quadrangular shape) on the surface (top and bottom surfaces) of the negative electrode 141 . Here, the negative electrode 141 corresponding to the gap between the negative electrode active materials 143 corresponds to the negative electrode uncoated portion 142 of the bridge in FIG. 5 . In addition, a negative electrode uncoated portion 141C in which the negative electrode active material 143 is not present may be formed at either end of both ends of the negative electrode 141 in the longitudinal direction. For reference, FIG. 6(b) is an enlarged view of a portion of FIG. 6(a).

The negative electrode body 140 may be obtained by punching or cutting the negative electrode 141 and the negative electrode active material 143 of FIG. 6 (b) along the cutting line CL2 of FIG. 6 (c). By punching or cutting along the cutting line CL2 of FIG. 6 (c), the same cathode body 140 as that of punching or cutting along the cutting line CL2 of FIG. 5 (b) can be obtained.

Referring to FIG. 6(c) , the cutting line CL2 includes the negative electrode non-coated portion 141C and the negative electrode active material 143 located at one end of both ends in the longitudinal direction of the negative electrode 141 (top in the case of the drawing). can be formed to The cutting line CL2 may be formed along the arrangement direction of the rectangular negative electrode active material 143, that is, along the length direction of the negative electrode 141, but leaving only a portion of the bridge negative electrode uncoated portion 142.

By punching or cutting along the cutting line CL2 of FIGS. 5(b) and 6(c), the cathode body 140 shown in FIG. 7(a) is obtained. Referring to FIG. 7(a) , the negative electrode body 140 is a negative electrode uncoated portion 141C formed on one side, an anode 141 having an anode active material 143 formed thereon, and a bridge anode uncoated portion connecting the anode active material 143. (142). At this time, the bridge cathode uncoated portion 142 is formed on the lower side of the portion where the anode active material 143 is formed, and the upper portion of the bridge anode uncoated portion 142 is a cathode incision where the anode 141 and the anode active material 143 do not exist. A portion 144 is formed.

The negative electrode cutout 144 corresponds to a gap separating neighboring negative electrode active materials 143 , that is, negative electrodes 141 in which the negative electrode active materials 143 are formed. Here, the cutting line CL2 is formed to coincide with the entire edge so that the cathode cutout 144, the bridge cathode uncoated portion 142, the anode active material 143, and the anode uncoated portion 141C can be simultaneously punched or cut. do.

In the case of the negative electrode body 140 shown in FIG. 7 (a), the portion of the negative electrode 141 on which the negative electrode active material 143 is formed and the negative electrode uncoated portion 141C are connected. ) is seven. Here, each negative electrode 141 on which the negative electrode active material 143 is formed corresponds to one negative electrode body in the prior art. However, in the case of the prior art, in order to electrically connect the seven negative electrode bodies, a process of collecting the negative electrode uncoated parts formed on each negative electrode body and welding the negative electrode tabs to the negative electrode uncoated parts gathered in one place is required. On the other hand, in the case of the negative electrode body 140 shown in FIG. 7 (a), seven negative electrodes 141 on which the negative electrode active material 143 is formed and the negative electrode uncoated portion 141C are attached to the bridge anode uncoated portion 142. Since they are connected by a process, there is no need for a process of bringing the existing cathode uncoated parts together. Instead, as shown in FIG. 7(b), by simply welding the negative electrode tab 310 to the negative electrode uncoated portion 141C, the anode 141 including the anode active material 143 and the bridge anode uncoated portion 142 The whole may be electrically connected to the negative electrode tab 310 .

In FIG. 7( b ), reference numeral 320 denotes an insulating portion and “330” denotes a welding portion.

Fig. 8(b) is a cross-sectional view along the cutting line B-B of Fig. 7(b). Referring to FIG. 8( b ), the positions of the negative electrode body 141, the negative electrode active material 143, the negative electrode uncoated portion 141C, the bridge anode uncoated portion 142, the negative electrode cutout 144, and the negative electrode tab 310 relationship can be seen.

The electrode assembly 100 according to an embodiment of the present invention includes the anode body 110 shown in FIG. 4(c), that is, the pocketing anode body 110 and the cathode body 140 shown in FIG. 7(b) It may be formed by folding the anode body 110 and the cathode body 140 in a zigzag shape in a state in which are positioned up and down. At this time, when the positive electrode body 110 and the negative electrode body 140 are folded in a zigzag shape while the entirety of the positive electrode body 110 and the negative electrode body 140 are positioned vertically, a portion in which the negative electrode bodies 140 directly contact each other occurs, and a short circuit of the battery may occur at this portion.

In order to prevent this problem from occurring, the electrode assembly 100 according to an embodiment of the present invention includes the anode body 110, the anode cutout 114, and the cathode cutout 144 of the cathode body 140. In this case, the anode body 110 and the cathode body 140 are alternately folded in a zigzag form with the anode cutout 114 and the cathode cutout 144 sandwiched between one end or a portion alternately up and down, can be formed

Referring to FIG. 9(a) , the anode body 110 has the anode cutout 114 facing upward and the cathode body 140 has the cathode cutout 144 facing downward, and the anode cutout 114 ) and the negative electrode cutout 144 are inserted into each other. At this time, the positive electrode cutout 114 and the negative electrode cutout ( 144) to each other.

In the case of FIG. 9 (a), from left to right, the positive electrode uncoated portion 111C, the negative electrode active material 143, the positive electrode active material 113, the negative electrode active material 143, the positive electrode active material 113, the negative electrode active material 143, and the positive electrode The active material 113 and the negative electrode active material 143 are positioned above.

When FIG. 9(a) is a plan view, FIG. 9(b) may be referred to as a front view or a rear view of FIG. 9(a). Referring to FIG. 9( b ) , it can be seen that the anode cutout 114 and the cathode cutout 144 are interposed in a form in which the anode body 110 and the cathode body 140 are alternately up and down.

In the state of FIG. 9(a), as shown in FIG. 9(c), in the anode body 110 and the cathode body 140, the anode cutout 114 and the cathode cutout 144 are alternately zigzag. can be folded As shown in FIG. 9(c), when the anode body 110 and the cathode body 140 are alternately folded in a zigzag shape, the electrode assembly 100 according to an embodiment of the present invention is obtained.

As described above, the anode body 110 includes the bridge anode uncoated portion 112 positioned at one end of the anode cutout 114, and the cathode body 140 is positioned at one end of the cathode cutout 144. It includes the bridge cathode uncoated portion 142, and the anode cutout portion 114 and the cathode cutout portion 144 face each other in a state where they are sandwiched with each other, and the anode uncoated portion 112 and the bridge cathode uncoated portion 142 are the same. It is folded in the direction to form the electrode assembly 100 .

That is, the portions folded in the zigzag direction (shape) in the state of FIG. 9 (a) are the anode cutout 114, the anode uncoated portion 112 of the bridge, the cathode cutout portion 144, and the anode uncoated portion 142 of the bridge.

Here, in the case of the anode body 110, not only the anode 111 and the bridge anode non-coated portion 112, but also the first and second separators 160 and the insulating member 170 include the anode 111 to the bridge anode uncoated portion ( 112), it can be folded in a zigzag form.

Meanwhile, FIG. 10 shows another embodiment of the anode body 410 and the cathode body 4400 . 10(a) and (b) show the anode body 410, FIG. 10(c) show the cathode body 440, and FIG. 10(d) show the anode body 410 and the cathode body A state in which the anode cutout 414 and the cathode cutout 444 of 440 are inserted is shown.

10 (a) and (b), the positive electrode body 410 includes a positive electrode active material 413, an anode incision 414, a bridge anode uncoated portion 412, anode uncoated portion 411C, first and second anode uncoated portions 411C. A second separator 460 and an insulating member 470 may be included. In addition, the negative electrode body 440 may include the negative electrode active material 443, the negative electrode cutout 444, the bridge negative electrode uncoated portion 442, and the negative electrode uncoated portion 414C.

In the positive electrode body 410 and the negative electrode body 440 shown in FIG. 10 , the shapes of the positive electrode uncoated portion 411C and the negative electrode uncoated portion 441C are different from those of the case described above, and most of the other parts are the same. In the case shown in FIG. 10, in a state where the anode body 410 and the cathode body 440 are arranged in the vertical direction, the anode cutout 414 and the cathode cutout 444 are inserted into each other, and then folded in a zigzag direction (Z- folding) to obtain the electrode assembly 100.

On the other hand, according to another field of the invention, the method of manufacturing the electrode assembly 100 described above includes the steps of preparing the anode body 110 as shown in FIGS. 2 to 9; providing a cathode body 140 on either the upper side or the lower side of the anode body 110; and folding the anode body 110 and the cathode body 140 in a zigzag shape.

Here, in the step of providing the cathode body 140 on either the upper or lower side of the anode body 110, the anode body 110 and the cathode body 140 have one end or part of each other alternately up and down. The anode body 110 and the cathode body 140 may be positioned alternately.

2 to 4, the step of preparing the positive electrode body 110 may include coating or applying a positive electrode active material 113 on at least one of the upper and lower surfaces of the positive electrode 111; Punching or cutting the positive electrode 111 on which the positive electrode active material 113 is formed; positioning the punched or cut anode 111 on a first separator 160 having an insulating member 170 formed on either an upper surface or a lower surface thereof; positioning a second separator 160 to cover the insulating member 170 and the cathode active material 113; and combining or bonding the insulating member 170 and the second separator 160.

In the step of punching or cutting the positive electrode 111, an anode cutout 114 in which the positive electrode 111 and the positive electrode active material 113 do not exist may be formed between the positive electrode active materials 113 adjacent to each other. there is.

In the step of punching or cutting the positive electrode 111 on which the positive electrode active material 113 is formed, one end in the longitudinal direction of the punched or cut positive electrode 111 is a positive electrode non-coated portion in which the positive electrode active material 113 does not exist ( 111C) can be formed.

The step of punching or cutting the positive electrode 111 on which the positive electrode active material 113 is formed, and the positive electrode 111 that is punched or cut on the first separator 160 having the insulating member 170 formed on either the upper or lower surface. A step of connecting the positive electrode tab 210 to the positive electrode uncoated portion 111C may be further included between the step of positioning the .

Between the step of punching or cutting the positive electrode 111 on which the positive electrode active material 113 is formed and the step of placing the punched or cut positive electrode 111 on the first separator 160, the first separator 160 A step of bonding the insulating member 170 to any one of the upper or lower surface of the ) or printing the insulating member 170 may be further included.

The insulating member 170 is punched so that the punched or cut anode 111 can be inserted into the space (the pocketing space) surrounded by the insulating member 170, and then bonded to the first separator 160. or can be printed.

The step of preparing the negative electrode body 140 may include coating or applying a negative electrode active material 143 on at least one of the upper and lower surfaces of the negative electrode 141; and punching or cutting the negative electrode 141 on which the negative electrode active material 143 is formed.

In the step of punching or cutting the negative electrode 141, the negative electrode 141 and the negative electrode active material 143 may have negative electrode cutouts 144 formed at regular intervals along the length direction of the negative electrode 141. .

In the step of punching or cutting the negative electrode 141 on which the negative electrode active material 143 is formed, one end in the longitudinal direction of the negative electrode 141 that is punched or cut is a negative electrode non-coated portion in which the negative electrode active material 143 does not exist ( 141C) is formed, and the negative electrode tab 310 may be connected to the negative electrode uncoated portion 141C.

In the step of providing the cathode body 140 on either the upper side or the lower side of the anode body 110, one end or part of the anode body 110 and the cathode body 140 are alternately alternated up and down. The cutout 114 and the cathode cutout 144 may be fitted to each other.

In the step of folding the anode body 110 and the cathode body 140 in a zigzag shape, the anode cutout 114 and the cathode cutout 144 sandwiched between each other may be alternately folded in a zigzag shape.

As described above, the embodiments of the present invention have been described with specific details such as specific components and limited embodiments and drawings, but these are provided only to help a more general understanding of the present invention, and the present invention is limited to the above embodiments. It is not, and those skilled in the art can make various modifications and variations from these descriptions. Therefore, the spirit of the present invention should not be limited to the described embodiments and should not be determined, and all things equivalent or equivalent to the claims as well as the following claims belong to the scope of the present invention.

100: electrode assembly for lithium secondary battery
110: anode
111: anode 112: bridge anode uncoated portion
113: cathode active material 114; bipolar incision
140: cathode body 141: cathode
142: bridge negative electrode non-coated portion 1431: negative electrode active material
144: anode incision 160: separator
170: insulating member

Claims (11)

bipolar body; and
A cathode body positioned on one of the upper and lower sides of the anode body; includes,
The anode body is provided in a form in which upper and lower surfaces and thickness surfaces are surrounded by a first separator, a second separator, and an insulating member,
An electrode assembly for a lithium secondary battery, characterized in that one end or part of each of the positive electrode body and the negative electrode body is provided in a folded form in a zigzag form in a state of alternating up and down with each other.
According to claim 1,
The anode is
anode; A cathode active material coated or coated on at least one of the upper and lower surfaces of the cathode; The first separator on which the positive electrode coated or coated with the positive electrode active material is placed; The insulating member formed on the upper surface of the first separator to surround the cathode active material and the thickness surface of the cathode; And the second separator bonded to the upper surface of the insulating member to cover the positive electrode active material and the positive electrode; includes,
An electrode assembly for a lithium secondary battery, characterized in that a cathode cutout portion in which the cathode and the cathode active material do not exist is formed between the cathode active materials adjacent to each other.
According to claim 2,
An electrode assembly for a lithium secondary battery, characterized in that a portion corresponding to the anode incision is formed in the first separator and the second separator.
According to claim 3,
The electrode assembly for a lithium secondary battery, characterized in that the positive electrode body includes a positive electrode uncoated portion in which the positive electrode active material does not exist in the positive electrode, and a positive electrode tab is connected to the positive electrode uncoated portion.
According to claim 4,
The electrode assembly for a lithium secondary battery, characterized in that the insulating member is formed to surround a thickness surface of the positive electrode and the positive electrode active material so that only the positive electrode tab is exposed.
According to claim 5,
The negative electrode is
A negative electrode and a negative electrode active material coated or coated on at least one of the upper and lower surfaces of the negative electrode;
An electrode assembly for a lithium secondary battery, characterized in that the negative electrode and the negative electrode active material are formed with negative electrode incisions at regular intervals along the longitudinal direction of the negative electrode.
According to claim 6,
The negative electrode body includes an anode uncoated portion in which the anode active material does not exist in the anode, and a negative electrode tab is connected to the anode uncoated portion.
According to claim 7,
An electrode assembly for a lithium secondary battery, characterized in that the positive electrode body and the negative electrode body are alternately folded in a zigzag form in a state in which one or a portion of the positive electrode body and the negative electrode body are interposed with each other so that one end or part thereof alternates up and down.
According to claim 8,
The cathode body and the cathode body electrode assembly for a lithium secondary battery, characterized in that the anode cutout and the cathode cutout are alternately folded in a zigzag form.
According to claim 9,
The anode body includes a bridge anode uncoated portion located at one end of the anode cutout,
The cathode body includes a bridge cathode uncoated portion positioned at one end of the cathode incision,
The electrode assembly for a lithium secondary battery, characterized in that the bridge anode uncoated portion and the bridge anode uncoated portion facing each other in a state where the anode cutout and the cathode cutout are inserted into each other are folded in the same direction.
According to claim 10,
The cathode body is an electrode assembly for a lithium secondary battery, characterized in that the first separator, the second separator and the insulating member are folded in a zigzag shape in the same way as the cathode.

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