Battery cell including protective member

Abstract

The present invention relates to a battery cell, comprising: an electrode assembly, the electrode assembly being configured to have a structure in which two or more unit stacks are connected in series or in parallel to each other; a battery case, the battery case being configured to accommodate the electrode assembly therein; and an insulating protective member, the protective member being configured to protect the electrode tab portion of the unit stack, wherein the battery case has a structure in which the overall length of the battery case is three times or more of the overall width of the battery case, and the positive electrode lead and the negative electrode lead extending outward from the battery case protrude in opposite directions. A longer battery cell is realized using a plurality of unit stacks, and the connection portion where the plurality of unit stacks are connected is strengthened, thereby improving the safety of the battery cell.

Description

Technical Field

[0001] This application claims the benefit of priority to Korean Patent Application No. 2020-0069119, filed on Jun. 8, 2020, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to a battery cell including a protective member, and more particularly, to a battery cell having an electrode assembly, which is composed of two or more unit stacks, is accommodated in a battery case and includes an insulating protective member configured to protect an electrode tab portion of the unit stack. Background Art

[0003] Since there is no need to replace the battery cell, a lithium secondary battery capable of charge and discharge is suitably used as a built-in battery cell, and has been applied to various devices with rapidly improved stability and rapidly increased capacity.

[0004] For example, lithium secondary batteries have been widely used as energy sources for wireless mobile devices or wearable devices worn on the body, which are small multifunctional products, and have also been used as energy sources for electric vehicles and hybrid electric vehicles proposed as alternatives to existing gasoline and diesel vehicles that cause air pollution.

[0005] In the case where the lithium secondary battery is used in a thin device such as a mobile phone, or includes a high-output, high-capacity battery cell configured to be set at the bottom of an electric vehicle, the lithium secondary battery can be manufactured to have a structure in which the lithium secondary battery has a smaller thickness and a larger planar area, or a structure in which the overall length of the lithium secondary battery is greater than the overall width of the lithium secondary battery.

[0006] In order to manufacture a battery cell having a larger plane area as described above, or a battery cell configured such that the overall length of the battery cell is greater than the overall width of the battery cell, a method of forming the electrode to have a larger size may be considered. However, this method requires replacement of existing equipment, thus requiring a large amount of additional cost and a long time.

[0007] Patent document 1 discloses a secondary battery, comprising: two or more electrode assemblies arranged side by side with a space provided between them; two or more electrode tabs accommodated in the two or more electrode assemblies; and a battery case having at least one accommodating portion configured to accommodate the two or more electrode assemblies therein, wherein a spacer provided in the space between the electrode assemblies has two or more placement portions configured to accommodate the electrode tabs.

[0008] In Patent Document 1, two or more electrode assemblies are accommodated in a battery case, thereby manufacturing a battery cell having a large plane area, and a spacer is provided in a space between the electrode assemblies in order to support and fix electrode tabs.

[0009] However, in Patent Document 1, the spacer merely supports and fixes the electrode tab. Therefore, in the case where the spacer is dislocated from its original position in the battery case, the electrode tab may be damaged due to the dislocation of the spacer.

[0010] Patent document 2 discloses a secondary battery configured to have a structure in which two or more stacked folding type unit batteries are installed in a battery housing, one or more electrode terminals protrude from opposite ends of each unit battery, and the unit batteries are installed in a receiving portion while forming a stacked arrangement structure or a planar arrangement structure with the electrode terminals connected to each other.

[0011] In Patent Document 2, a separate reinforcing member is not added to a connection portion that connects a plurality of unit batteries housed in a battery case to each other, so that insulation between the unit batteries may be broken due to an external impact.

[0012] Therefore, there is a need for a battery cell having a larger planar area or having a structure in which an overall length of the battery cell is greater than an overall width of the battery cell, in which the safety of the battery cell is improved while preventing an internal short circuit of the battery cell.

[0013] (Prior art literature)

[0014] (Patent Document 1) Korean Patent Application Publication No. 2016-0132145 (November 17, 2016)

[0015] (Patent Document 2) Korean Patent Application Publication No. 2007-0116295 (December 10, 2007) Summary of the invention

[0016] Technical issues

[0017] The present invention has been made in view of the above problems, and an object of the present invention is to provide a battery cell, which is configured to have such a structure, that is, two or more unit stacks are accommodated in a battery casing, and the battery casing is configured so that the overall length of the battery casing is several times or more than the overall width of the battery casing, thereby the battery cell has a long-cell structure, wherein the battery cell includes a protective member, and the protective member is configured to ensure insulation between the unit stacks and prevent damage to the electrode tab portion due to external impact.

[0018] Technical Solution

[0019] In order to achieve the above-mentioned purpose, the battery cell according to the present invention includes: an electrode assembly, which is configured to have a structure in which two or more unit stacks are connected in series or in parallel with each other; a battery case, which is configured to accommodate the electrode assembly therein; and an insulating protective member, which is configured to protect the electrode tab portion of the unit stack, wherein the battery case has a structure in which the overall length of the battery case is more than three times the overall width of the battery case, and the positive lead and the negative lead extending outward from the battery case protrude in opposite directions.

[0020] In the battery cell according to the present invention, each of the unit stacks may be a stacked electrode assembly, a stacked folded electrode assembly, a laminated stacked electrode assembly, or a combination thereof, and each of the unit stacks may have a positive electrode tab bundle consisting of a plurality of positive electrode tabs combined with each other and a negative electrode tab bundle consisting of a plurality of negative electrode tabs combined with each other.

[0021] In the battery cell according to the present invention, the protection member may include a first protection member added to a connection portion in which the unit stacks are connected to each other in the electrode assembly.

[0022] In addition, the protection member may further include a second protection member added to a tab-lead bonding portion in the electrode assembly where each of the positive electrode lead and the negative electrode lead extending outward from the battery case and an electrode tab bundle are bonded to each other.

[0023] In addition, the first protection member may be configured to have a structure that wraps the electrode tab portion and an end portion of the unit stack adjacent to the electrode tab portion together.

[0024] The second protection member may be configured to have a structure that wraps the tab-lead bonding portion of the electrode assembly and an end portion of a unit stack adjacent to the tab-lead bonding portion.

[0025] In the battery cell according to the present invention, the first protection member may be formed to wrap the electrode tab portion, and the second protection member may be formed to wrap the tab-lead bonding portion.

[0026] In the battery cell according to the present invention, the protective member may include a third protective member, which is configured to have a connecting portion connecting the unit stacks to each other, a tab-lead connecting portion where each of the positive lead and the negative lead extending outward from the battery case is connected to an electrode tab bundle, and a structure wrapping the outer surface of each of the unit stacks.

[0027] In the battery cell according to the present invention, the unit stacks may be connected in series to each other, and each of the unit stacks may be configured to have a structure in which positive electrode tab bundles protrude in a first direction and negative electrode tab bundles protrude in a second direction opposite to the first direction.

[0028] In the battery cell according to the present invention, the unit stacks may be connected in parallel to each other, and the unit stacks may include: a first unit stack located at each of the opposite ends of the electrode assembly, and a second unit stack other than the first unit stack, the first unit stack may be configured to have a structure in which two electrode tab bundles formed at the first electrode protrude in a first direction of the unit stack and in a second direction opposite to the first direction, respectively, and one electrode tab bundle formed at the second electrode protrudes in the first direction or the second direction, and the second unit stack may be configured to have a structure in which two positive electrode tab bundles and two negative electrode tab bundles protrude in the first direction and the second direction, respectively.

[0029] In the battery cell according to the present invention, the width of the electrode tab bundle of the first cell stack protruding outward from the battery case may be greater than the width of other electrode tab bundles of the first cell stack and the width of each electrode tab bundle of the second cell stack.

[0030] Furthermore, the present invention provides a battery pack including the battery cell as a single battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is an exploded perspective view of the battery unit according to the first embodiment.

[0032] Figure 2 is added with Figure 1 Plan view and side view of the electrode assembly of the protection member.

[0033] Figure 3 is a plan view of an electrode assembly to which a protection member according to a second embodiment is added.

[0034] Figure 4 is a plan view of an electrode assembly to which a protection member according to a third embodiment is added.

[0035] Figure 5 are a plan view and a side view of an electrode assembly to which a protection member according to a fourth embodiment is added.

[0036] Figure 6 are perspective views of protective members of various shapes. DETAILED DESCRIPTION

[0037] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the preferred embodiments of the present invention. However, in describing the working principle of the preferred embodiments of the present invention in detail, when the detailed description of the known functions and structures incorporated herein may obscure the subject matter of the present invention, the detailed description will be omitted.

[0038] In addition, the same reference numerals will be used throughout the drawings to represent components that perform similar functions or operations. Where a component is referred to as being connected to another component throughout the application, the component may not only be directly connected to the other component, but the component may also be indirectly connected to the other component via another component. In addition, including a certain element does not mean excluding other elements, but means that other elements may be further included unless otherwise specified.

[0039] Furthermore, unless otherwise specifically limited, the description that specifies elements by limitation or addition is applicable to all inventions and does not limit the specific invention.

[0040] Furthermore, in the description of the present invention and the claims of this application, unless otherwise mentioned, the singular form is intended to include the plural form.

[0041] In addition, in the description of the present invention and the claims of the present application, unless otherwise mentioned, "or" includes "and". Therefore, "including A or B" refers to three cases, namely, the case including A, the case including B, and the case including A and B.

[0042] Furthermore, all numerical ranges include the lowest value, the highest value and all intermediate values ​​therebetween unless the context clearly dictates otherwise.

[0043] Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0044] Figure 1 is an exploded perspective view of a battery unit according to a first embodiment, Figure 2 is added with Figure 1 Plan view and side view of the electrode assembly of the protection member.

[0045] Reference Figure 1 and Figure 2 , the battery cell 100 is configured to have a structure in which five cell stacks 110 electrically connected to each other are accommodated in a pouch-shaped battery case 130 made of a laminate sheet.

[0046] The battery case 130 has a structure in which the overall length L of the battery case is more than three times the overall width W of the battery case. In particular, the overall length of the battery case may be more than 5 times the overall width of the battery case. As described above, the present invention can provide a battery cell having a relatively long length in one direction.

[0047] The battery case according to the present invention is not limited to Figure 1 and Figure 2 Also included in the scope of the present invention is a structure in which a plurality of unit stacks are accommodated in a prismatic battery case in a state of being connected to each other.

[0048] In addition, the present invention includes an electrode assembly configured to have a structure in which five unit stacks are housed in a battery case 130 in a state of being connected in series or in parallel to each other, rather than an electrode assembly consisting of electrodes having sizes corresponding to the overall length L and overall width W of the battery case 130.

[0049] Therefore, the electrode assembly according to the present invention can be manufactured using two or more unit stacks, each of which is composed of electrodes, each of which is configured such that the length in the x-axis direction is about 1.5 times the length in the y-axis direction. Alternatively, the electrode assembly can be manufactured using three or more unit stacks, each of which is composed of electrodes, each of which is configured such that the length in the y-axis direction is the same as the length in the x-axis direction.

[0050] Each unit stack 110 may be a stacked type electrode assembly, a stacked folded type electrode assembly, a laminated stacked type electrode assembly, or a combination thereof. A plurality of unit stacks may be composed of the same kind of electrode assemblies or different kinds of electrode assemblies. Figure 2 The unit stack body 110 shown in FIG. 1 has a structure in which a positive electrode 113 and a negative electrode 114 are stacked. For convenience of description, a separator is omitted.

[0051] Figure 2 The unit stack shown in may be a stacked type electrode assembly, a stacked folding type electrode assembly, or a laminated stacked type electrode assembly.

[0052] Although in Figure 1 , an electrode assembly configured such that five unit stacks are connected to each other in series is shown, but the number of unit stacks may be variously set.

[0053] Each unit stack 110 is configured such that a positive electrode tab bundle 111 composed of a plurality of positive electrode tabs bonded to each other and a negative electrode tab bundle 112 composed of a plurality of negative electrode tabs bonded to each other are formed to protrude in different directions, and a positive electrode lead 117 and a negative electrode lead 118 extending outward from a battery case 130 protrude in opposite directions.

[0054] When the unit stacks 110 are connected in series, as shown in FIG. Figure 1 and Figure 2 In the illustrated electrode assembly, the positive electrode and the negative electrode constituting the unit stack 110 may be composed of electrodes having the same size and shape, and a positive electrode formed with a single positive electrode tab and a negative electrode formed with a single negative electrode tab may be used.

[0055] Therefore, in order to manufacture a battery cell having a longer length, a positive electrode and a negative electrode manufactured in a single process may be used, and thus neither an additional process nor a dual process is required to manufacture a battery cell having a longer length.

[0056] Each unit stack 110 is manufactured using a positive electrode formed with a single positive electrode tab and a negative electrode formed with a single negative electrode tab, and each individual unit stack forms a single positive electrode tab bundle 111 and a single negative electrode tab bundle 112 .

[0057] In each individual unit stack, a single positive electrode tab bundle 111 protrudes in a first direction, and a single negative electrode tab bundle 112 protrudes in a second direction opposite to the first direction.

[0058] The battery cell according to the present invention includes an insulating protection member configured to protect the electrode tab portion of the cell stack 110. Figure 1 and Figure 2 In the electrode assembly of FIG. 1 , the first protective member 120 is added to a connection portion where the unit stacks 110 are connected to each other.

[0059] Figure 1 It is shown that the first protection member 120 that passes through the positive electrode lead 117 and the leftmost one of the cell stacks 110 is mounted to a connection portion 125 where the cell stacks 110 are connected to each other.

[0060] The positive electrode tab bundle 111 of any one of the unit stacks 110 is electrically connected to the negative electrode tab bundle 112 of an adjacent one of the unit stacks, and the negative electrode tab bundle 112 of any one of the unit stacks 110 is electrically connected to the positive electrode tab bundle 111 of an adjacent one of the unit stacks. The first protective member 120 is configured to have a structure that wraps together an electrode tab portion that combines the positive electrode tab bundle and the negative electrode tab bundle with each other, and ends of the two opposing unit stacks 110 adjacent to the electrode tab portion.

[0061] Considering that the first protective member 120 passes through the unit stack and is disposed at the connection portion, the first protective member 120 may be formed to have a size equal to or larger than the outer circumference of the unit stack, and the first protective member 120 mounted to the connection portion may be configured to be fixed to the outer surface of the end of the unit stack. Therefore, the first protective member according to the present invention can be stably fixed without being separated from the position where the first protective member is initially disposed.

[0062] In addition, in the case where a space is formed between the first protective member and the electrode tab portion and the first protective member is made of a material capable of maintaining a quadrilateral ring shape, as Figure 1 As shown in , external force applied to the electrode tab portion can be absorbed, and thus damage to the electrode tab portion can be prevented.

[0063] Furthermore, since the first protective member wraps the end portion of the unit stack, the separator can be prevented from being loosened or folded in the process of injecting the electrolyte into the battery case.

[0064] Figure 3 is a plan view of an electrode assembly to which a protection member according to a second embodiment is added.

[0065] Reference Figure 3 , the electrode assembly is configured to have a structure in which five unit stacks are connected to each other in parallel.

[0066] and Figure 3 Unlike that shown in , the number of unit stacks constituting the electrode assembly is not limited to five, and the electrode assembly may be composed of less than five unit stacks or more than five unit stacks.

[0067] Because in Figure 3 The electrode assembly shown in FIG. 1 is a block diagram of an electrode assembly in which the unit stacks are connected in parallel to each other. Figure 1 and Figure 2 Compared to the unit stack shown in , the number of electrode tabs is changed.

[0068] Specifically, the unit stack is composed of a first unit stack 210a located at opposite ends of the electrode assembly and a second unit stack 210b located in the electrode assembly except for the opposite ends of the electrode assembly. That is, the second unit stack 210b is a unit stack other than the first unit stack 210a.

[0069] Since the leftmost first unit stack of the two first unit stacks 210 a includes a positive electrode formed with two positive electrode tabs and a negative electrode formed with one negative electrode tab, two positive electrode tab bundles 211 a and 211 and one negative electrode tab bundle 212 are formed.

[0070] The two positive electrode tab bundles 211 a and 211 protrude in first and second directions which are opposite directions, and the negative electrode tab bundle 212 protrudes in a direction toward the second unit stack 210 b .

[0071] Considering the rate performance and resistance of the battery cell, the width of the positive tab bundle 211 a may be formed to be greater than the width of the positive tab bundle 211 .

[0072] Since the first unit stack 210a located at the right end of the electrode assembly includes a positive electrode formed with one positive electrode tab and a negative electrode formed with two negative electrode tabs, one positive electrode tab bundle 211 and two negative electrode tab bundles 212 and 212a are formed.

[0073] The two negative electrode tab bundles 212 and 212 a protrude in first and second directions which are opposite directions, and the positive electrode tab bundle 211 protrudes in a direction toward the second unit stack 210 b .

[0074] Considering the rate performance and resistance of the battery cell, the width of the negative electrode tab bundle 212 a may be formed to be greater than the width of the negative electrode tab bundle 212 .

[0075] In addition, the width of the positive electrode tab bundle 211 and the width of the positive electrode tab bundle 211 a may be formed to be equal to each other, and the width of the negative electrode tab bundle 212 and the width of the negative electrode tab bundle 212 a may be formed to be equal to each other.

[0076] In the case where the widths of the positive electrode tab bundles 211a and 211 are equal to each other and the widths of the negative electrode tab bundles 212 and 212a are equal to each other as described above, the second unit stack 210b formed with two positive electrode tab bundles and two negative electrode tab bundles can be manufactured using the positive electrode and the negative electrode manufactured by a single process. In addition, each of the first unit stacks 210a disposed at opposite ends of the electrode assembly can be manufactured by removing any one of one negative electrode tab bundle and one positive electrode tab bundle from the second unit stack 210b.

[0077] Since the second unit stack 210b is connected in parallel with the unit stacks adjacent thereto, the second unit stack includes a positive electrode formed with two positive electrode tabs and a negative electrode formed with two negative electrode tabs. Therefore, two positive electrode tab bundles 211 and two negative electrode tab bundles 212 are formed in the second unit stack 210b. The two positive electrode tab bundles 211 protrude in the first direction and the second direction in opposite directions, and the two negative electrode tab bundles 212 protrude in the first direction and the second direction in opposite directions.

[0078] The first protective member 220 and the second protective member 230 are added to Figure 3The first protective member 220 may be added to each of the connection portions where the first unit stack 210a and the second unit stack 210b are connected to each other, and the second unit stack 210b and the second unit stack 210b are connected to each other, and the second protective member 230 may be added to the tab-lead bonding portion where each of the positive electrode lead 217 and the negative electrode lead 218 extending outward from the battery case and the electrode tab bundle are bonded to each other.

[0079] That is, at each of a portion where the positive lead 217 is coupled to the positive tab bundle 211 a and a portion where the negative lead 218 is coupled to the negative tab bundle 212 a, a second protective member 230 may be added to an outer surface of each of the positive lead 217 and the negative lead 218 housed in the battery case.

[0080] The second protective member 230 may be formed into a quadrilateral ring shape that maintains a shape like the first protective member 220, and may be formed to be larger than the outer periphery of each of the first unit stack 210a and the second unit stack 210b, or may be formed to have a size that allows the second protective member to be fixed to the outer surface of each of the unit stacks 210a and 210b in close contact.

[0081] When describing the function of the second protective member, the description of the first protective member may be equally applied to the second protective member.

[0082] Figure 4 is a plan view of an electrode assembly to which a protection member according to a third embodiment is added.

[0083] Reference Figure 4 , the electrode assembly is with Figure 3 The electrode assembly has the same structure as the electrode assembly, in which five unit stacks 310 are connected in parallel to each other.

[0084] Therefore, refer to Figure 3 The description of the electrode assembly given is equally applicable to Figure 4 electrode assembly.

[0085] The third protective member 340 configured to insulate the electrode tab portion of the unit stack 310 is added to the Figure 4 The third protective member 340 is configured to have a connection portion 325 connecting the unit stacks 310 to each other, a tab-lead bonding portion where each of the positive and negative electrode leads extending outward from the battery case and the electrode tab bundle are bonded to each other, and a structure that wraps the outer surface of each unit stack 310.

[0086] That is, the third protective member 340 may be configured to have a structure that wraps the entire outer surface of the electrode assembly except for the positive electrode lead 317 and the negative electrode lead 318 extending outward from the battery case.

[0087] When the third protective member 340 having the above structure is used, the third protective member wraps the entire outer surface of the electrode assembly composed of a plurality of unit stacks, thereby obtaining a uniform thickness of the electrode assembly, thereby preventing the outer surface of the battery case from being bent or curved.

[0088] Furthermore, since the third protective member is added, the rigidity of the electrode assembly can be ensured, thereby preventing damage to the electrode assembly in addition to damage to the electrode tab portion due to a force applied to the outer surface of the electrode assembly.

[0089] Figure 5 are a plan view and a side view of an electrode assembly to which a protection member according to a fourth embodiment is added.

[0090] Reference Figure 5 , the electrode assembly has Figure 1 and Figure 2 Therefore, referring to Figure 1 and Figure 2 The description given of the electrode assembly is equally applicable to the electrode assembly according to this embodiment.

[0091] The first protective member 420 and the second protective member 430 are added to Figure 5 electrode assembly.

[0092] The first protective member 420 is added to a connection portion where the unit stacks 410 are connected to each other, and the second protective member 430 is added to a tab-lead bonding portion where each of the positive and negative leads 417 and 418 extending outward from the battery case and the electrode tab bundle are bonded to each other.

[0093] The first protection member 420 is formed to wrap the electrode tab portion, and the second protection member 430 is formed to wrap the tab-lead bonding portion.

[0094] Specifically, the outer circumference of each of the first and second protective members 420 and 430 is smaller than the outer circumference of each unit stack 410. The width and height of each of the first and second protective members 420 and 430 are formed smaller than those of the unit stack 410.

[0095] Therefore, due to the first protective member 420 and the second protective member 430, the rigidity of the electrode tab portion and the tab-lead bonding portion can be ensured, and since the portions to which the first protective member 420 and the second protective member 430 are added do not protrude from the outer surface of the battery case, the thickness of the battery cell will not increase even when the protective members are added.

[0096] In a specific example, each of the first protective member 420 and the second protective member 430 may be implemented by a heat shrink tube. The heat shrink tube may be added to the outer surface of each of the electrode tab portion and the tab-lead bonding portion in a close contact manner due to instantaneous shrinkage. In order to prevent a short circuit from occurring due to contact between adjacent electrode tab bundles during shrinkage, as described above, it is preferred to apply these protective members to an electrode assembly in which a plurality of unit stacks are connected in series to each other, rather than an electrode assembly in which a plurality of unit stacks are connected in parallel to each other.

[0097] Figure 6 are perspective views of protective members of various shapes.

[0098] Reference Figure 6 , the (A) type protection member may have a size larger than the outer circumference of the unit stack so as to be installed while passing through the unit stack.

[0099] The (B) type protection member is composed of a pair of separable structures. The (B) type protection member can not only Figure 5 The embodiment shown in FIG. 1 is formed to have a smaller circumference than that of the unit stack, and can also be applied to an electrode assembly to which a type (A) protective member is added according to the circumference of the protective member. That is, a pair of protective members can be combined with each other in a state where the pair of protective members are provided at the connection portion.

[0100] (C) The protective member may be a heat shrink tube and may be applied to Figures 1 to 5 All types of protective components shown in .

[0101] The (D) type protective member may be composed of two films, which can be attached to each other by being heated and pressed in a state where they are set at the upper and lower parts of each of the electrode contact part and the contact-lead bonding part, or each of the two films may be provided with an adhesive layer, wherein the two films can be attached to each other after the two films are set so that the adhesive layers face each other.

[0102] The present invention provides a battery pack including a battery cell as a single battery, the battery cell including an electrode assembly to which a protection member is added.

[0103] The battery cell is configured to have a structure in which the overall length of the battery cell is greater than the overall width of the battery cell and a protection member capable of preventing a short circuit is added to the battery cell, thereby improving the safety of the battery cell. The battery cell can be applied to a device that requires high capacity and high output, such as an electric vehicle or a hybrid electric vehicle, and has a space with a low height and a long length so that a battery pack can be disposed therein.

[0104] Those skilled in the art to which the present invention pertains will appreciate that various applications and modifications are possible within the scope of the present invention based on the above description.

[0105] (Explanation of reference numbers)

[0106] 100: Battery Cell

[0107] 110, 310, 410: unit stack

[0108] 111, 211, 211a: positive electrode connector bundle

[0109] 112, 212, 212a: Negative electrode connection bundle

[0110] 113: Positive electrode

[0111] 114: Negative electrode

[0112] 117, 217, 317, 417: Positive lead

[0113] 118, 218, 318, 418: Negative lead

[0114] 120, 220, 420: first protection member

[0115] 125, 325: Connecting part

[0116] 130: Battery housing

[0117] 210a: First unit stack

[0118] 210b: Second unit stack

[0119] 230, 430: Second protection member

[0120] 340: Third protection member

[0121] W: Overall width

[0122] L: Overall length.

[0123] Industrial Applicability

[0124] As is apparent from the above description, the battery cell according to the present invention uses an electrode assembly configured to have a structure in which a plurality of unit stacks each composed of smaller electrodes are connected to each other, rather than using an electrode assembly composed of electrodes having a size corresponding to the size of the receiving portion of the battery case of the battery cell, and still realizes a case where the battery cell is configured to have a structure in which the overall length of the battery cell is several times greater than the overall width of the battery cell. Therefore, it is not necessary to separately manufacture an electrode configured to have a structure in which the overall length of the electrode is greater than the overall width of the electrode.

[0125] That is, existing battery cell manufacturing equipment can be used without modification, so additional cost and time for building a production facility are not required.

[0126] Furthermore, the protection member configured to protect the electrode tab portion of the unit stack has a structure that wraps the electrode tab portion where the electrode tab bundle is located and the end of the unit stack adjacent to the electrode tab portion, thereby fixing the position of the protection member.

[0127] Furthermore, since the protection member is used, the electrode tab portion can be protected from external force.

[0128] In addition, in a battery pack including a larger battery cell according to the present invention, assuming that the sizes of the battery pack casings are equal to each other, the number of battery cells accommodated therein can be reduced. Therefore, the number of connecting members for electrically connecting the battery cells to each other can be reduced, thereby increasing the energy density of the battery pack.

Claims

1. A battery cell, comprising: an electrode assembly configured to have a structure in which two or more unit stacks are connected to each other in series or in parallel; a battery housing configured to accommodate the electrode assembly therein; as well as an insulating protective member configured to protect an electrode tab portion of the unit stack, wherein the battery housing has a structure in which the overall length of the battery housing is more than three times the overall width of the battery housing, and The positive electrode lead and the negative electrode lead extending outward from the battery case protrude in opposite directions, wherein the protective member comprises a first protective member, the first protective member being added to a connection portion of the electrode assembly where the unit stacks are connected to each other, the first protective member being formed to have a size equal to or larger than an outer circumference of the unit stack and being made of a material capable of maintaining a quadrilateral ring shape, the first protective member being arranged to be fixed to an outer surface of an end portion of the unit stack and being configured to have a structure that wraps together the electrode tab portion and an end portion of an opposite unit stack adjacent to the electrode tab portion, wherein a space is formed between the first protective member and the electrode tab portion so that the electrode tab portion does not contact the first protective member, wherein the protection member further includes a second protection member added to a tab-lead bonding portion in the electrode assembly where each of the positive electrode lead and the negative electrode lead extending outward from the battery case and an electrode tab bundle are bonded to each other.

2. The battery cell according to claim 1, wherein each of the unit stacks is a stacked electrode assembly, a stacked folded electrode assembly, a laminated stacked electrode assembly, or a combination thereof, and Each of the unit stacks has a positive electrode tab bundle consisting of a plurality of positive electrode tabs bonded to each other and a negative electrode tab bundle consisting of a plurality of negative electrode tabs bonded to each other. 3 . The battery cell according to claim 1 , wherein the first protection member is configured to have a structure that wraps the electrode tab portion and an end portion of the unit stack adjacent to the electrode tab portion together. 4 . The battery cell according to claim 1 , wherein the second protection member is configured to have a structure that wraps the tab-lead bonding portion of the electrode assembly and an end portion of a unit stack adjacent to the tab-lead bonding portion.

5. The battery cell according to claim 2, wherein the unit stacks are connected in series with each other, and Each of the unit stacks is configured to have a structure in which a positive electrode tab bundle protrudes in a first direction and a negative electrode tab bundle protrudes in a second direction opposite to the first direction.

6. The battery cell according to claim 2, wherein the unit stacks are connected in parallel to each other, The unit stack comprises: a first unit stack located at each of opposite ends of the electrode assembly, and a second unit stack other than the first unit stack, The first unit stack is configured to have a structure in which two electrode tab bundles formed at the first electrode protrude in a first direction of the unit stack and in a second direction opposite to the first direction, respectively, and one electrode tab bundle formed at the second electrode protrudes in the first direction or the second direction, and The second unit stack is configured to have a structure in which two positive electrode tab bundles and two negative electrode tab bundles protrude in the first direction and the second direction, respectively. 7 . The battery cell according to claim 6 , wherein a width of an electrode tab bundle of the first unit stack protruding outward from the battery case is greater than a width of other electrode tab bundles of the first unit stack and a width of each electrode tab bundle of the second unit stack.

8. A battery pack comprising the battery unit according to any one of claims 1 to 7 as a single battery.

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