Cross-citation with relevant application(s)
This application claims the benefit of priority based on Korean Patent Application No. 10-2017-0137663 dated October 23, 2017, and all contents disclosed in the literature of the Korean patent application are incorporated as part of this specification.
The present invention relates to a secondary battery, and more particularly, to a pouch type secondary battery.
【Background technology】
The secondary battery may be classified according to the structure of the electrode assembly having the anode/separator/cathode structure. Typically, the long sheet-like anodes and cathodes are wound in a state in which a separator is interposed, a wound-type electrode assembly, and a plurality of anodes and cathodes cut in units of a predetermined size are sequentially stacked in a state via a separator. Stacked or stacked electrode assembly, stacked/folded electrode assembly in a structure in which bi-cell l or pull l cel l, in which a certain unit of anodes and cathodes are stacked with a separator interposed therebetween, is stacked. ' Etc.

Recently, a pouch-type secondary battery having a structure in which a stacked or stacked/folded electrode assembly is embedded in a pouch-shaped case of an aluminum laminate sheet has attracted attention. The pouch type secondary battery has advantages of low manufacturing cost, small weight, and easy shape modification.

【Detailed description of the invention】

【Technical tasks】

In the pouch type secondary battery, the size of the lead connected to the electrode assembly embedded in the case and exposed to the outside of the case is bound to be limited by the size of the pouch type secondary battery. For example, the lead of a thin pouch-type secondary battery must be thinned. When the size of the lead is small, when the size of the current through the lead is increased, heat generation increases, which may cause problems in terms of stability.

Technical problem to be solved by the present invention is to reduce the resistance of the lead

The present invention provides a pouch type secondary battery that can reduce heat generated in the lead and prevent sealing failure due to the lead.

【Technical Solution】

• A secondary battery according to an embodiment of the present invention includes an electrode assembly, a case including a sealing portion surrounding the electrode assembly, and a lead electrically connected to the electrode assembly and extending in one direction. The lid is in contact with the electrode assembly and is located in the first region located inside the case, the second region exposed to the outside of the case, and between the first region and the second region, and the sealing portion of the case And a third region overlapping with the third region, wherein the third region has a wider width than the first region and the second region in the second direction, and the first region and the second region in the third direction. It has a thinner thickness, the second direction is perpendicular to the first direction, and the third direction is perpendicular to the first direction and the second direction.

The entire thickness of the third region may be thinner than the thickness of the first region and the second region.

The crab 3 region may include a portion protruding by a first width difference to one side in the second direction from the first region and the second region.

The crab 3 region may further include a portion protruding by a difference in width of the crab 2 on the opposite side of the second direction than the first region and the second region.

The difference in width of the crab 1 and the difference in width of the crab 2 may be the same.

The first width difference and the second width difference may be different from each other.

The third region may be formed to be thinner than the first region and the second region by a first thickness difference in one direction in the three directions.

The third region may be formed to be thinner than the first region and the second region by a thickness difference of two crabs on the opposite side of the three directions.

The difference in thickness of the crab and the difference in thickness of the second may be the same.

The first thickness difference and the second thickness difference may be different from each other.

【Effects of the Invention】

By reducing the resistance of the lead in the secondary battery, heat generated in the lead can be reduced, and sealing failure due to the lead can be prevented.

【Simple explanation of drawings】

1 is an exploded perspective view showing a secondary battery according to an embodiment of the present invention.

FIG. 2 is a plan view showing the lead of FIG. 1 in more detail.

3 is a side view showing the lead of FIG. 1 in more detail.

4 is a plan view showing another embodiment of the planar structure of the lid. 5 is a plan view showing another embodiment of the planar structure of the lid. 6 is a side view showing another embodiment of the structure on the side of the lid. 7 is a side view showing another embodiment of the structure on the side of the lid. [Mode for the Invention]

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily practice. The present invention can be implemented in many different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification.

Throughout the specification, when a part is "connected" to another part, it is not only "directly connected", but also "electrically connected 1 " with another element in between. Also includes. Also, when a part “includes” a certain component, this means that other components may be further included instead of excluding other components, unless otherwise stated.

Hereinafter, a secondary battery according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

1 is an exploded perspective view showing a secondary battery according to an embodiment of the present invention.

Referring to FIG. 1, the secondary battery 10 includes an electrode assembly 110, a plurality of electrode tabs 111 and 112 connected to the electrode assembly 110, a case 120 accommodating the electrode assembly 110, and a plurality of It includes a plurality of leads 130 are connected to the electrode tab (111, 112).

The electrode assembly 110 is a power generation element in which an anode and a cathode are sequentially stacked in a state where a separator is interposed, and may be formed in a stacked or stacked/folded structure. However, the structure of the electrode assembly (no) is not limited, and according to an embodiment, the electrode assembly (no) may be formed of a structure in which a long sheet-like anode and a cathode are wound in a state where a separator is interposed.

■ The plurality of electrode tabs 111 and 112 may include a first electrode tab (in) extending from the anode of the electrode assembly (no) and a second electrode tab (112) extending from the cathode of the electrode assembly (110). have.

The case 120 may include a case 1 121 and a case 2 126 that face each other with the electrode assembly 110 interposed therebetween. The crab case 121 may include a concave shape receiving portion S on which the electrode assembly 110 can be seated, and a gap U sealing region A around the receiving portion S. The second case 126 may be formed in a plate shape capable of covering the top surface of the electrode assembly 110, and may include a second sealing region B in contact with the first sealing region A. The first case 121 and the almost 12 case 126 may be made of an aluminum laminate structure of a resin layer/metal thin film layer/resin layer. In FIG. 1, although the first case 121 is illustrated as including the storage portion S, and almost 12 cases 126 are formed in a plate shape, the structure of the case 120 that can accommodate the electrode assembly 110 is It is not limited, and the case 120 may be modified in various structures.

The plurality of leads 130 are electrically connected to the first electrode tab 111 and the second electrode tab 112, and a part of the secondary battery 10 is exposed to the outside of the case 120 when the assembly of the secondary battery 10 is completed. One of the plurality of leads 130 may be welded and electrically connected to the first electrode map 111, and the other of the plurality of leads 130 may be welded and electrically connected to the second electrode map 112. That is, one of the plurality of leads 130 may be the lead of the positive electrode and the other may be the lead of the negative electrode.

After receiving the electrode assembly 110 in the storage portion (S) of the crab case 121, and electrically connect the leads 130 to each of the first electrode tab 111 and the second electrode wrap 112, The first sealing region (A) and the second sealing region (B) of the first sealing region (A) and the second sealing region (B) of the second sealing case (126) are in contact with the second sealing region (B) of the first case (121). In overlapping areas

The assembly of the secondary battery 10 can be completed by adhering the resin case to each other by applying heat and pressure to bond the first case 121 and the second case 126. The portion where the first sealing region A and the second sealing region B are joined in the case 120 becomes a sealing portion for sealing the electrode assembly 110 in the secondary battery 10. The sealing portion of the case 120 may surround the electrode assembly 110 to seal the electrode assembly 110 from the outside of the case 120.

In FIG. 1, the first electrode tab 111 and the second electrode tab 112 extend from the electrode assembly 110 in the crab 1 direction D1, and the crab 1 electrode tab 111 and the second electrode tab 112 ) It has been illustrated that the leads 130 connected to each extend in the first direction D1. However, this is not a limitation, and according to an embodiment, the first electrode tab 111 and the nearly 12 electrode tab 112 extend in different directions, so that a plurality of leads 130 extend in different directions. It might be. For example, one of the first electrode tab 111 and the second electrode tab 112 extends in the first direction D1, and the other extends in the second direction D2, and one of them extends. The lead 130 of the extend in the first direction (D1), the other lead 130 may be extended in the second direction (D2) of the shop. The crab 2 direction D2 may be perpendicular to the crab 1 direction D1.

In addition, the first electrode map 111 and the second electrode tab 112 may be provided in plural, and thus the number of the leads 130 may be determined.

Hereinafter, a lead 130 according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 and 3.

FIG. 2 is a plan view showing the lead of FIG. 1 in more detail. 3 is a side view showing the lead of FIG. 1 in more detail.

2 and 3, the lead 130 includes a conductive metal portion 131 and a film portion 135.

The conductive metal portion 131 may be formed of a single conductor, and the first region 131a, the second region 131b, and the third region 131c in the first direction D1 in which the lead 130 extends. Can be divided into. The first region 131a may directly contact the electrode tabs 111 and 112 and may be a portion located inside the case 120. The second region 131b may be a portion exposed to the outside of the case 120. The third area 131c is U

Located between the region 131a and the crab 2 region 131b, it may be a portion overlapping the sealing portion of the case 120.

As illustrated in FIG. 2, on a plane, the first region 131a and the second region 131b have a width 1 in the second direction D2, and the third region 131c is the second In the direction D2, the crab may have 2 widths W2. The plane shape means a plane parallel to the first direction D1 and the second direction D2. The second width W2 is greater than the crab 1 width W1. That is, the third region 131c may have a wider width than the first region 131a and the second region 131b in the second direction D2.

The third region 131c is a portion protruding by a width difference (Wdl) by one width difference (Wdl) to one side of the second direction (D2) than the first region (131a) and the second region (131b), and the opposite side of the second direction (D2). As a result, a region protruding by a width difference (Wd2) of 2 may be included. The first width difference Wdl and the second width difference Wd2 may be the same. That is, the crab 3 region 131c may include protruding portions of the same size protruding to both sides of the second direction D2. Depending on the embodiment, the first width difference Wdl and the second width difference Wd2 may be different from each other. Alternatively, one of the crab width difference (Wdl) and the crab width difference (Wd2) may be 0. That is, the third region 131c may include protruding portions of different sizes protruding to both sides of the second direction D2, or one protruding portion protruding to one side of the second direction D2. Can be.

As illustrated in FIG. 3, on the side, the crab 1, the region 131a and the second region 131b have the crab 1 thickness TH1 in the third direction D3, and the third region 131c is the first It may have a second thickness (ΊΉ2) in three directions (D3). The third direction (D3) is a direction perpendicular to the first direction (D1) and the second direction (D2), and the side view refers to a side or second formed by the first direction (D1) and the third direction (D3). It means a side surface formed by the direction D2 and the third direction D3. The second thickness (ΊΉ2) is smaller than the crab 1 thickness (ΊΉ1). That is, the third region 131c may have a thickness thinner than the first region 131a and the second region 131b in the third direction D3.

The third region 131c is formed to be thinner by the first thickness difference THdl in one direction in the third direction D3 than in the first region 131a and the second region 131b, and toward the opposite side in the third direction D3. It may be formed as thin as the second thickness difference THd2. The first thickness difference (THdl) and the second thickness difference (THd2) may be the same. That is, the third region 131c may be formed to be concave upward and downward in the thirteenth direction D3 to have a thickness thinner than the first region 131a and the almost twelve region 131b.

According to an embodiment, the first thickness difference THdl and the second thickness difference THd2 may be different from each other. Alternatively, any one of the first thickness difference THdl and the second thickness difference THd2 may be 0. That is, the crab 3 regions 131c may be concavely formed at different depths in the upper and lower sides of the third direction D3 or concave upward or downward in the third direction D3.

The film portion 135 may be attached to the upper and lower surfaces of the three regions 131c of the conductive metal portion 131 to increase the sealing degree of the case 120. When the first case 121 and the second case 126 are adhered, the film portion 135 overlaps the sealing portion of the case 120 to increase the sealing degree of the case 120.

As described above, the thickness of the entire third area 131c overlapping the sealing portion of the case 120 in the lead 130 is formed to be thinner than the thickness of the first area 131a or the second area 131b, By forming the width of the third region 131c wider than the width of the first region 131a or the second region 131b, a thinner lead 130 that can be used for the thin secondary battery 10 is provided. And, as the thickness of the lead 130 becomes thinner, the resistance of the lead 130 may not be increased and the resistance of the lead 130 may be reduced, and the sealing of the case 120 that may be caused by the lead 130 may occur. Defect can be prevented. Hereinafter, a lead having a shape different from that of the lead 130 of FIG. 2 will be described with reference to FIGS. 4 and 5. The difference will be mainly described in comparison with FIG. 2.

4 is a plan view showing another embodiment of the planar structure of the lid. Compared to FIG. 2, in the lead 130 of FIG. 4, the crab width difference (Wd2) (see FIG. 2) becomes 0, and the first width difference (Wdl) may be further increased. That is, the third region 131c in the conductive metal portion 131 of the lead 130 has a total width difference (Ml) on one side of the second direction D2 from the first region 131a and the second region 131b. ), and may not include the projected portion on the opposite side of the second direction D2.

Except for the differences, features described in the embodiment of FIG. 2 may be applied to all of the embodiment of FIG. 4, and thus overlapping descriptions between the embodiments are omitted. 5 is a plan view showing another embodiment of the planar structure of the lid.

Compared to FIG. 2, in the lead 130 of FIG. 5, the first width difference Wdl (see FIG. 2) becomes 0, and the crab 2 width difference Wd2 may be further increased. That is, in the conductive metal portion 131 of the lead 130, the third region 131c has a difference in width of the width of two from the first region 131a and the second region 131b to the opposite side of the second direction D2 (Wd2) ), and a protruding portion may not be included in one side of the second direction D2.

Except for these differences, features described in the embodiment of FIG. 2 can be applied to all of the embodiment of FIG. 5, and thus overlapping descriptions between the embodiments are omitted. Hereinafter, a lead having a shape different from that of the lead 130 of FIG. 3 will be described with reference to FIGS. 6 and 7. Compared with FIG. 3, the difference will be mainly described.

6 is a side view showing another embodiment of the structure on the side of the lid. Compared to FIG. 3, in the lead 130 of FIG. 6, the second thickness difference THd2 (see FIG. 3) becomes 0, and the first thickness difference THdl may be further increased. That is, the third region 131c in the conductive metal portion 131 of the lead 130 has a thickness difference (THdl) of one side in the third direction D3 from the first region 131a and the second region 131b. ), the first region 131a, the second region 131b, and the thirteenth region 131c may be formed flat in one plane on the opposite side of the third direction D3. That is, the crab 3 region 131c of the conductive metal portion 131 may be formed concave upward. The side structure of the lead 130 of FIG. 6 can be applied to the planar structure of the lead 130 of FIGS. 2, 4 and 5.

Except for these differences, features described in the embodiment of FIG. 3 can be applied to all of the embodiment of FIG. 6, and thus overlapping descriptions between the embodiments are omitted. 7 is a side view showing another embodiment of the structure on the side of the lid. Compared to FIG. 3, the first thickness difference THdl (see FIG. 3) is shown in the lead 130 of FIG. 7. It becomes 0, and the second thickness difference THd2 may become larger. That is, in the conductive metal portion 131 of the lead 130, the third region 131c has a second thickness difference (THd2) opposite to the first direction 131a and the second area 131b in the third direction D3. ), and the first region 131a, the second region 131b, and the third region 131c may be flat in one plane on one side of the third direction D3. That is, the third region 131c of the conductive metal portion 131 may be concave downward. Fig. 7

The side-side structure of the lead 130 can be applied to the planar structure of the lead 130 of FIGS. 2, 4 and 5.

Except for these differences, features described in the embodiment of FIG. 3 can be applied to all of the embodiment of FIG. 7, and thus overlapping descriptions between the embodiments are omitted. The drawings referenced so far and the detailed description of the described invention are merely illustrative of the present invention, which are used for the purpose of describing the present invention only and are used to limit the scope of the present invention as defined in the claims or the claims. It is not. Therefore, those skilled in the art , it will be understood the various modifications and equivalent embodiments are possible that changes therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

Claims】

【Claim 1】Electrode assembly;

A case including a sealing portion surrounding the electrode assembly; And

And a lead electrically connected to the electrode assembly and extending in a first direction,

The Sanglead

A U-region in contact with the electrode assembly and located inside the case;

A second area exposed to the outside of the case; And

Located between the crab 1 area and the crab 2 area, and includes a crab 3 area overlapping the sealing portion of the case,

The third region has a wider width than the first region and the second region in the second direction, and has a thinner thickness than the first region and the second region in the third direction,

' The second direction of the system is perpendicular to the first direction of the crab, and the third direction of the second battery is perpendicular to the second U-direction and the second direction.

【Claim 2】

According to claim 1,

The secondary battery is formed so that the thickness of the entire region 3 is thinner than the thickness of the first region and the second region.

【Claim 3】

According to claim 2,

The third region includes a secondary battery including a region protruding by a first width difference to one side in the second direction from the crab 1 region and the crab 2 region.

【Claim 4】

According to claim 3,

The third region further includes a portion protruding only a second width difference from the first region and the second region to the opposite side of the second direction.

【Claim 5】

According to claim 4,

The first width difference and the second width difference is the same secondary battery.

【Claim 6】

According to claim 4,

The secondary width difference between the first width difference and the second width is different.

【Claim 7】

According to claim 12,

The third region is a secondary battery formed thinner by a first thickness difference in one direction in the third direction than the first region and the second region.

【Claim 8】

According to claim 7,

The secondary region is formed to have a thickness that is thinner than the first region and the second region by a second thickness difference on the opposite side of the third direction.

【Claim 9】

According to almost 18,

The difference between the thickness of the above 1 and the thickness of the second is the same secondary battery.

【Claim 10】

The method of claim 8,

The difference in the first thickness and the difference in the second thickness are different secondary batteries.