Battery cells, battery modules including battery cells, and battery packs including battery modules

Abstract

The present invention provides a battery cell, a battery module, and a battery pack including the same, capable of preventing breakage of electrode tabs protruding from electrodes, preventing short circuits between the electrode tabs and surrounding electrodes, and reducing resistance between the electrode tabs and electrode leads. The battery cell according to the present invention includes an electrode assembly including an electrode tab stacking part in which electrodes and electrode tabs protruding from the electrodes are aligned and stacked in a vertical direction, and an electrode lead including a lead coupling part enveloping at least a portion of the electrode tab stacking part, the lead coupling part continuously surrounding and contacting a top surface of the electrode tab stacking part, a first side surface connected to the top surface, and one of a second side surface opposite to the first side surface and a bottom surface opposite to the top surface, and exposing the other of the second side surface and the bottom surface opposite to the top surface.

Description

[Technical field]

[0001] The present invention relates to a battery cell, a battery module including the battery cell, and a battery pack including the battery module, and more particularly to a battery cell, a battery module, and a battery pack having an improved shape of an electrode lead. This application claims priority to Korean Patent Application No. 10-2022-0110396 filed on August 31, 2022, and Korean Patent Application No. 10-2022-0152044 filed on November 14, 2022, and the entire contents disclosed in the specification and drawings of said applications are incorporated herein by reference. [Background technology]

[0002] Secondary batteries, which have high applicability to various products and electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are driven by electric drive sources. These secondary batteries have not only the temporary advantage of dramatically reducing the use of fossil fuels, but also the advantage of not producing any by-products associated with energy use, and are therefore attracting attention as a new energy source that is environmentally friendly and improves energy efficiency.

[0003] Currently widely used types of secondary batteries include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, and nickel zinc batteries. For example, the lithium ion battery may be formed by coating a positive electrode active material (e.g., lithium composite transition metal oxide) on a positive electrode collector and coating a negative electrode active material (e.g., carbon material) on a negative electrode collector (e.g., copper, stainless steel, aluminum, nickel, carbon, copper, etc.). Recently, lithium sulfur batteries that can replace lithium ion batteries have been attracting attention as next-generation secondary batteries. The lithium sulfur battery uses a sulfur-based compound as a positive electrode active material and an alkali metal such as lithium metal as a negative electrode, and can have a higher energy density than existing lithium secondary batteries.

[0004] Meanwhile, a battery cell includes an electrode (e.g., a negative electrode), and an electrode tab (e.g., a negative electrode tab) protruding from the electrode is joined to an electrode lead to guide (lead) the electrode to the outside of the battery cell. Typically, the electrode lead is manufactured in a plate shape and joined to the electrode tab at the top surface of the electrode lead. When the electrode and the electrode tab are made of lithium metal having a relatively low rigidity, the reliability of the electrode tab may be questionable in the process of joining the electrode tab and the electrode lead by pressing them together using an ultrasonic method. For example, the electrode tab may break in the area where the ultrasonic wave is applied. In addition, there is a concern that the electrode tab may be pushed out and cause a short circuit with a surrounding electrode (e.g., another adjacent electrode tab). Therefore, when joining the electrode tab while maintaining the existing structure of the electrode lead, there is a high risk of defects occurring during the manufacture of a secondary battery such as a lithium-sulfur battery. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a battery cell, a battery module and a battery pack including the same, which can prevent breakage of electrode tabs protruding from electrodes, prevent short circuits between the electrode tabs and surrounding electrodes, and reduce resistance between the electrode tabs and electrode leads. [Means for solving the problem]

[0006] In order to solve the above problems, a battery cell according to one aspect of the present invention includes an electrode assembly including an electrode tab stacking portion in which electrodes and electrode tabs protruding from the electrodes are aligned and stacked in a vertical direction, and an electrode lead including a lead coupling portion that wraps around at least a portion of the electrode tab stacking portion, wherein the lead coupling portion continuously surrounds and contacts a top surface of the electrode tab stacking portion, a first side surface connected to the top surface, and either a second side surface opposite the first side surface or a bottom surface opposite the top surface, and may expose the other of the second side surface and the bottom surface opposite the top surface.

[0007] In an embodiment, the electrode tab stacking portion may have a rear surface opposite to a protruding direction of the electrode tabs, and the lead coupling portion may expose the rear surface of the electrode tab stacking portion.

[0008] In an embodiment, a width of the lead coupling portion in a direction perpendicular to a protruding direction of the electrode tabs may be greater than a width of the electrode tab stacking portion in a direction perpendicular to the protruding direction of the electrode tabs.

[0009] In an embodiment, a height of the lead coupling portion in the vertical direction may be greater than a height of the electrode tab stacking portion in the vertical direction.

[0010] In one embodiment, the electrode lead may further include an extension portion extending from the lead connection portion to guide (lead) the electrode to the outside of the battery cell, and a width of the lead connection portion in a direction perpendicular to the protruding direction of the electrode tab may be greater than a width of the extension portion in a direction perpendicular to the protruding direction of the electrode tab.

[0011] In an embodiment, the lead coupling portion may be bent at a right angle from a corner portion where surfaces of the electrode tab laminated portion are connected to each other, and may enclose at least a portion of the electrode tab laminated portion.

[0012] In an embodiment, the lead coupling portion may be curved from a corner portion where surfaces of the electrode tab laminated portion are connected to each other to enclose at least a portion of the electrode tab laminated portion.

[0013] In an embodiment, the lead coupling portion may be shaped to protrude from a side surface of the extension portion.

[0014] In one embodiment, the lead coupling portion may have a stiffness greater than the stiffness of the electrode tab.

[0015] In one embodiment, each of the electrode tabs may be made of lithium metal.

[0016] In one embodiment, the lead bond may be made of a metal other than lithium metal.

[0017] In one embodiment, the electrode is a negative electrode, the electrode tab is a negative electrode tab and is made of lithium metal, the electrode tab laminate portion is a negative electrode tab laminate portion, the electrode assembly further includes a positive electrode tab laminate portion in which a separator is interposed between each of the negative electrodes and a positive electrode tab protruding from the positive electrode are aligned and laminated in a vertical direction, the positive electrode tab is made of a metal other than lithium metal, the negative electrode tab laminate portion and the positive electrode tab laminate portion are formed to be aligned with each other on one side of the electrode assembly, and the second side surface or the bottom surface of the negative electrode tab laminate portion exposed by the lead coupling portion may not face the positive electrode tab laminate portion.

[0018] In one embodiment, a contact portion between the lead coupling portion and the negative electrode tab lamination portion may be compressed, so that the negative electrode tab lamination portion may expand while being restrained by the lead coupling portion.

[0019] According to another aspect of the present invention, a battery cell includes an electrode assembly including an electrode tab stacking portion in which electrodes and electrode tabs protruding from the electrodes are aligned and stacked in a vertical direction, and an electrode lead including a lead coupling portion enveloping at least a portion of the electrode tab stacking portion, wherein the lead coupling portion may expose at least one of a top surface of the electrode tab stacking portion, a first side surface connected to the top surface, a second side surface opposite the first side surface, a bottom surface opposite the top surface, and a back surface connected to the bottom surface and opposite the protruding direction of the electrode tabs.

[0020] The lead coupling portion may be in contact with the top surface, the back surface, and the bottom surface, and may expose the first side surface and the second side surface.

[0021] The lead coupling portion may be in contact with the top surface, the first side surface, the second side surface, and the bottom surface, and may expose the rear surface.

[0022] The electrode tab stacking portion may further define an intermediate surface located between the top surface and the bottom surface and parallel to the top surface and the bottom surface, and the lead coupling portion may contact the top surface, the intermediate surface, and the bottom surface and expose the first side surface, the second side surface, and the rear surface.

[0023] In order to solve the above problems, a battery module and a battery pack according to the present invention may include a battery cell according to an embodiment of the present invention as described above. Effect of the Invention

[0024] The battery cell according to the present invention may include an electrode tab laminated portion in which electrode tabs are aligned and laminated, and an electrode lead connected to the electrode tab laminated portion. The electrode lead may include a lead coupling portion that encases at least a portion of the electrode tab laminated portion, and for example, the electrode lead may contact a top surface, a first side surface, and a second side surface of the electrode tab laminated portion. Since the electrode lead, which has a relatively high rigidity, is formed to encase the electrode tab laminated portion, which has a relatively low rigidity, the electrode lead may prevent the electrode tab laminated portion from breaking during the process of joining the electrode lead and the electrode tab laminated portion.

[0025] In addition, the electrode lead may expose the bottom surface and the back surface of the electrode tab laminated portion, and the bottom surface and the back surface of the electrode tab laminated portion may not face the peripheral electrode. In the process of joining the electrode lead and the electrode tab laminated portion, the contact portion between the lead coupling portion and the electrode tab laminated portion is crimped, and the electrode tab laminated portion may expand while being restrained by the lead coupling portion. In other words, the electrode tab laminated portion may be pushed toward the exposed bottom surface and back surface, but may not be pushed toward the top surface, the first side surface, and the second side surface covered by the lead coupling portion. As a result, a short circuit between the electrode tab laminated portion and the peripheral electrode may not occur.

[0026] In addition to the above, in a battery cell according to another aspect of the present invention, the lead coupling portion may expose at least one of a top surface, a first side surface, a second side surface, a bottom surface, and a back surface of the electrode tab stacking portion, and according to another aspect of the present invention, a bonding area is increased compared to a conventional case in which an electrode lead is bonded to an electrode tab at the top surface of the electrode tab.

[0027] In this way, since the electrode lead envelops at least a part of the electrode tab laminated portion, not only can the safety of the joint between the electrode tab and the electrode lead be ensured, but also the joint area between the electrode tab and the electrode lead can be increased, the joint strength can be improved, and the contact resistance can be reduced. Since the shape in which the electrode lead envelops at least a part of the electrode tab laminated portion can be maintained even during use, there is an effect that the improved joint strength can be maintained, making it easier to move a current.

[0028] The following drawings attached to this specification are intended to illustrate preferred embodiments of the present invention and serve to facilitate a further understanding of the technical ideas of the present invention as well as the contents of the invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief description of the drawings]

[0029] [Figure 1] 1 is a plan view illustrating a battery cell according to an embodiment of the present invention; [Diagram 2] 2 is a perspective view for explaining an example of a first electrode lead included in the battery cell of FIG. 1. [Diagram 3] 2 is a cross-sectional view taken along line AA' in FIG. 1. [Figure 4] 2 is a cross-sectional view taken along line BB' in FIG. 1. [Diagram 5] 2 is a cross-sectional view taken along line CC' in FIG. 1. [Figure 6] 2 is a perspective view illustrating an example of a method for manufacturing the battery cell of FIG. 1. FIG. [Figure 7] 2 is a perspective view illustrating an example of a method for manufacturing the battery cell of FIG. 1. FIG. [Figure 8] 2 is a perspective view illustrating an example of a method for manufacturing the battery cell of FIG. 1. FIG. [Figure 9] 1. FIG. 4 is a perspective view illustrating another example of a method for manufacturing the battery cell of FIG. [Figure 10]1. FIG. 4 is a perspective view illustrating another example of a method for manufacturing the battery cell of FIG. [Figure 11] 1. FIG. 4 is a perspective view illustrating another example of a first electrode lead included in the battery cell of FIG. [Figure 12] FIG. 4 is a plan view illustrating a battery cell according to another embodiment of the present invention. [Figure 13] 13 is a perspective view illustrating an example of a first electrode lead included in the battery cell of FIG. 12. FIG. [Figure 14] FIG. 11 is a perspective view illustrating a first electrode lead included in a battery cell according to yet another embodiment of the present invention. [Figure 15] FIG. 11 is a perspective view illustrating a first electrode lead included in a battery cell according to yet another embodiment of the present invention. [Figure 16] FIG. 11 is a perspective view illustrating a first electrode lead included in a battery cell according to yet another embodiment of the present invention. [Figure 17] 1 is a diagram illustrating a battery module including a battery cell according to an embodiment of the present invention; [Figure 18] 18 is a diagram for explaining a battery pack including the battery module of FIG. 17. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The present invention will become more clear by describing in detail preferred embodiments of the present invention with reference to the attached drawings. The embodiments described herein are merely illustrative to aid in understanding the invention, and it should be understood that the present invention can be implemented in various forms different from the embodiments described herein. In addition, in order to aid in understanding the invention, the attached drawings are not drawn to scale, and the dimensions of some components may be exaggerated.

[0031] Fig. 1 is a plan view illustrating a battery cell according to an embodiment of the present invention. Fig. 2 is a perspective view illustrating an example of a first electrode lead included in the battery cell of Fig. 1. Fig. 3 is a cross-sectional view taken along line A-A' in Fig. 1. Fig. 4 is a cross-sectional view taken along line B-B' in Fig. 1. Fig. 5 is a cross-sectional view taken along line C-C' in Fig. 1.

[0032] Referring first to FIG. 1 , a battery cell 10 according to one embodiment of the present invention may include an electrode assembly 100, a first electrode lead 210, and a second electrode lead 220.

[0033] The electrode assembly 100 may include a negative electrode 110, a positive electrode 120, a separator, a negative electrode tab laminate 112, and a positive electrode tab laminate 122.

[0034] In one embodiment, the negative electrode 110 and the positive electrode 120 may be arranged alternately as shown in FIG. 3 and FIG. 4. For example, the positive electrode 120 may be arranged between the negative electrodes 110. A separator may be sandwiched between the positive electrode 120 and the negative electrode 110. Thus, the electrode assembly 100 may be a stacked electrode assembly or a stack / folded electrode assembly. For example, the stacked electrode assembly may have a structure in which positive electrodes and negative electrodes cut into units of a predetermined size are stacked in sequence with a separator sandwiched therebetween, and the stack / folded electrode assembly may have a structure in which a bi-cell or a full-cell in which positive electrodes and negative electrodes of a predetermined unit are stacked with a separator sandwiched therebetween is wound up.

[0035] 3, in one embodiment, the negative electrode tabs 111 may protrude from the negative electrode 110 in a first direction D1 (e.g., a protruding direction). The negative electrode tabs 111 may be stacked in a third direction D3 (e.g., a vertical direction). The negative electrode tab stacking portion 112 may refer to a configuration in which the negative electrode tabs 111 are aligned and stacked.

[0036] In one embodiment, the positive electrode tabs may protrude in a first direction D1 from the positive electrode 120. The positive electrode tabs may also be stacked in a third direction D3. The positive electrode tab stacking portion 122 may refer to a configuration in which the positive electrode tabs are aligned and stacked.

[0037] 1, the negative electrode tab laminate portion 112 and the positive electrode tab laminate portion 122 may be formed to be aligned with each other on one side of the electrode assembly 100. Also, the negative electrode tab laminate portion 112 and the positive electrode tab laminate portion 122 may be formed to be spaced apart from each other. This allows the first electrode lead 210 and the second electrode lead 220 to be disposed to be spaced apart from each other.

[0038] In one embodiment, the negative electrode 110 and the negative electrode tab 111 may be made of an alkali metal, such as lithium metal. For example, the electrode assembly 100 may be an electrode assembly for implementing a lithium-sulfur battery, and the positive electrode 120 may be coated with a positive electrode active material that includes a sulfur compound.

[0039] The first electrode lead 210 may be electrically connected to the electrode assembly 100 via the negative electrode tab laminate 112. For example, the first electrode lead 210 may be joined to the negative electrode tab laminate 112. The first electrode lead 210 may be joined to the negative electrode tab laminate 112 using a known joining method. For example, the first electrode lead 210 may be joined to the negative electrode tab laminate 112 using a pressure joining method, an ultrasonic joining method, a resistance joining method, a laser joining method, or the like. Thereby, the first electrode lead 210 may be in contact with the negative electrode tab laminate 112 and may lead (lead) the negative electrode 110 to the outside of the battery cell 10. In this way, the first electrode lead 210 may be a negative electrode lead.

[0040] The second electrode lead 220 can be electrically connected to the electrode assembly 100 via the positive tab stack 122. For example, the second electrode lead 220 can be joined to the positive tab stack 122. In this manner, the second electrode lead 220 can be a positive lead.

[0041] In one embodiment, the stiffness of the first electrode lead 210 may be even greater than the stiffness of the negative electrode tab 111. For example, the negative electrode tab 111 may be made of lithium metal, and the first electrode lead 210 may be made of a metal other than lithium metal (e.g., silver, copper, gold, aluminum, tungsten, zinc, nickel, pure iron, steel, platinum, tin, lead, nichrome, brass, bronze, etc.). When the first electrode lead 210 is made of a metal other than lithium metal, the brittle nature of lithium metal can be compensated for to compensate for the properties of the negative electrode tab 111, which may be made of lithium metal.

[0042] The battery cell 10 according to one embodiment of the present invention particularly includes an improved first electrode lead 210. The first electrode lead 210 will be described in further detail with reference to FIGS.

[0043] 2 to 5, the first electrode lead 210 may include a first lead coupling portion 211 and a first extension portion 212. The first lead coupling portion 211 may be formed to surround at least a portion of the negative electrode tab laminate portion 112 and may be in contact with the negative electrode tab laminate portion 112. The first lead coupling portion 211 may have a shape protruding from a side surface of the first extension portion 212. The first extension portion 212 may extend from the first lead coupling portion 211 to lead the negative electrode 110 to the outside of the battery cell 10.

[0044] In one embodiment, the first lead coupling portion 211 may include a top surface contact portion UC, a first side surface contact portion SC1, and a second side surface contact portion SC2.

[0045] The top surface contact portion UC may contact the top surface USF of the negative electrode tab stack portion 112. The first side surface contact portion SC1 may contact the first side surface SSF1 of the negative electrode tab stack portion 112. The second side surface contact portion SC2 may contact the second side surface SSF2 of the negative electrode tab stack portion 112.

[0046] For example, the first side surface SSF1 may be connected to the top surface USF, and the second side surface SSF2 may be connected to the top surface USF and be opposite to the first side surface SSF1, so that the first lead coupling portion 211 can contact the negative electrode tab stack portion 112 while continuously surrounding the top surface USF, the first side surface SSF1, and the second side surface SSF2.

[0047] In one embodiment, the first lead coupling portion 211 may be bent at a right angle from a corner portion where the surfaces of the negative electrode tab lamination portion 112 are connected to each other, and may enclose at least a portion of the negative electrode tab lamination portion 112. For example, the first lead coupling portion 211 may be bent at a right angle from a corner portion where the top surface USF and the first side surface SSF1 of the negative electrode tab lamination portion 112 are connected (for example, a portion where the top surface contact portion UC and the first side surface contact portion SC1 are connected). Also, the first lead coupling portion 211 may be bent at a right angle from a corner portion where the top surface USF and the second side surface SSF2 of the negative electrode tab lamination portion 112 are connected (for example, a portion where the top surface contact portion UC and the second side surface contact portion SC2 are connected).

[0048] In one embodiment, the first lead coupling portion 211 may have a first width W1 in a direction (e.g., second direction D2) perpendicular to the protruding direction of the negative electrode tab 111, and the negative electrode tab laminated portion 112 may have a second width W2 in the direction (e.g., second direction D2) perpendicular to the protruding direction of the negative electrode tab 111. In this case, the first width W1 may be greater than the second width W2, so that the first lead coupling portion 211 can fully encase the negative electrode tab laminated portion 112 (W1>W2).

[0049] Furthermore, the width of the first extension portion 212 may be the same as the width of the first lead coupling portion 211 , or may be greater than the width of the negative electrode tab laminate portion 112 .

[0050] In one embodiment, the first lead coupling portion 211 may have a first height H1 in the vertical direction (e.g., the third direction D3), and the negative electrode tab stacking portion 112 may have a second height H2 in the vertical direction (e.g., the third direction D3). In this case, the first height H1 may be greater than the second height H2, so that the first lead coupling portion 211 can fully encase the negative electrode tab stacking portion 112.

[0051] In addition, the first lead coupling portion 211 may expose a bottom surface LSF and a back surface BSF of the negative electrode tab laminated portion 112. For example, the bottom surface LSF may be opposite to the top surface USF and connected to the first and second side surfaces SSF1 and SSF2. The back surface BSF may be opposite to the protruding direction (e.g., the first direction D1) of the negative electrode tab 111.

[0052] The first extension portion 212 may extend from the first lead coupling portion 211. The first extension portion 212 may lead the negative electrode 110 to the outside of the battery cell 10. In one embodiment, as shown in FIG. 2, the first extension portion 212 may extend from an upper portion of the first lead coupling portion 211. For example, the first extension portion 212 may be formed integrally with the first lead coupling portion 211. However, the present invention is not limited thereto, and the first extension portion 212 may extend from an intermediate portion or a lower portion of the first lead coupling portion 211.

[0053] The battery cell 10 may include a negative electrode tab laminate 112 in which the negative electrode tabs 111 are aligned and laminated, and a first electrode lead 210 connected to the negative electrode tab laminate 112. The first electrode lead 210 may encase at least a portion of the negative electrode tab laminate 112, and for this purpose, the first electrode lead 210 may include a top surface contact portion UC, a first side surface contact portion SC1, and a second side surface contact portion SC2. The first electrode lead 210, which has a relatively high rigidity, is formed to encase the negative electrode tab laminate 112, which has a relatively low rigidity, so that in the process of joining the first electrode lead 210 and the negative electrode tab laminate 112, the first electrode lead 210 can prevent the negative electrode tab laminate 112 from breaking.

[0054] In addition, the first electrode lead 210 may expose the bottom surface LSF and the back surface BSF of the negative electrode tab laminate 112, and the bottom surface LSF and the back surface BSF of the negative electrode tab laminate 112 may not face the positive electrode tab laminate 122. In the process of joining the first electrode lead 210 and the negative electrode tab laminate 112, the contact portion between the first lead coupling portion 211 and the negative electrode tab laminate 112 is crimped, and the negative electrode tab laminate 112 may spread in a state of being restrained by the first lead coupling portion 211. In other words, the negative electrode tab laminate 112 may be pushed in the direction of the exposed bottom surface LSF and back surface BSF, but may not be pushed by the top surface USF, the first side surface SSF1, and the second side surface SSF2 covered by the first lead coupling portion 211. This allows for no shorting between the negative electrode tab stack 112 and the surrounding electrodes (eg, positive electrode tab stack 122).

[0055] 6 to 8 are perspective views illustrating an example of a method for manufacturing the battery cell of FIG.

[0056] 6, the spare first electrode lead P210 may include a spare first lead coupling portion P211 and a first extension portion 212. The spare first lead coupling portion P211 may be a spare member for forming the above-mentioned first lead coupling portion 211, and may be flat so as to be parallel to a plane formed in the first direction D1 and the second direction D2. The first extension portion 212 may extend from the spare first lead coupling portion P211 in the plane. In this case, the width PW1 of the spare first lead coupling portion P211 may be even larger than the width PW2 of the first extension portion 212.

[0057] 7, the spare first electrode lead P210 and the negative electrode tab laminate 112 approach each other, and a portion of the spare first lead coupling portion P211 may contact the negative electrode tab laminate 112. For example, the portion of the spare first lead coupling portion P211 may contact the uppermost negative electrode tab among the negative electrode tabs 111 aligned in the negative electrode tab laminate 112.

[0058] 8, the spare first lead coupling part P211 may be bent to correspond to the shape of the negative electrode tab lamination part 112. For example, the spare first lead coupling part P211 may be bent and joined to the negative electrode tab lamination part 112 using any one of the joining methods described above. This allows the first lead coupling part 211 to be formed to enclose at least a portion of the negative electrode tab lamination part 112.

[0059] According to the manufacturing method described above with reference to FIGS. 6 to 8, the flat preliminary first lead coupling part P211 is brought into contact with the negative electrode tab lamination part 112, and then bent to correspond to the shape of the negative electrode tab lamination part 112 to form the first lead coupling part 211. As a result, the contact area between the first lead coupling part 211 and the negative electrode tab lamination part 112 can be increased, and the electrical resistance between the first lead coupling part 211 and the negative electrode tab lamination part 112 can be reduced. In addition, the negative electrode tab 111 is pressed by the bottom surface LSF and / or back surface BSF of the negative electrode tab lamination part 112 that does not face the peripheral electrode, so that a short circuit between the negative electrode tab lamination part 112 and the peripheral electrode (e.g., the positive electrode tab lamination part 122) can be prevented.

[0060] 9 and 10 are perspective views illustrating another example of a method for manufacturing the battery cell of FIG.

[0061] 9, the first electrode lead 210 may include a first lead coupling portion 211 and a first extension portion 212. The first lead coupling portion 211 and the first extension portion 212 may be the first lead coupling portion 211 and the first extension portion 212 described above based on FIG. 2. In other words, the first electrode lead 210 may be pre-formed to wrap around at least a portion of the negative electrode tab laminate portion 112 in accordance with the shape of the negative electrode tab laminate portion 112. In this case, the width PW1 of the first lead coupling portion 211 may be substantially the same as the width PW2 of the first extension portion 212.

[0062] Referring to FIG. 10, the first electrode lead 210 and the negative electrode tab stacking portion 112 are pressed close to each other, so that the top surface contact portion UC, the first side surface contact portion SC1, and the second side surface contact portion SC2 of the first lead coupling portion 211 can come into contact with the negative electrode tab stacking portion 112.

[0063] 9 and 10, the first electrode lead 210 can be pre-formed in accordance with the shape of the negative electrode tab laminated part 112. As a result, the productivity of the bonding process of the first electrode lead 210 and the negative electrode tab laminated part 112 can be improved, and the phenomenon in which the negative electrode tab 111 is pressed can be relatively reduced.

[0064] FIG. 11 is a perspective view illustrating another example of a first electrode lead included in the battery cell of FIG.

[0065] 11, the first electrode lead 210' may include a first lead coupling portion 211' and a first extension portion 212. The first lead coupling portion 211' may include a top surface contact portion UC', a first side surface contact portion SC1', and a second side surface contact portion SC2'. However, the first electrode lead 210' may have substantially the same shape as the first electrode lead 210 described above with reference to FIG. 2, except for the shape of the corner portions described below.

[0066] In one embodiment, the first lead coupling portion 211' may be curved from a corner portion where the surfaces of the negative electrode tab lamination portion 112 are connected to each other, and may wrap at least a portion of the negative electrode tab lamination portion 112. For example, the first lead coupling portion 211' may be curved from a corner portion where the top surface USF and the first side surface SSF1 of the negative electrode tab lamination portion 112 are connected (for example, a portion where the top surface contact portion UC' and the first side surface contact portion SC1' are connected). Also, the first lead coupling portion 211' may be curved from a corner portion where the top surface USF and the second side surface SSF2 of the negative electrode tab lamination portion 112 are connected (for example, a portion where the top surface contact portion UC' and the second side surface contact portion SC2' are connected). If the negative electrode tab laminated portion 112 is bent into a curved shape from the corner portion where the surfaces are connected, it is possible to prevent stress concentration at the bent portion compared to when it is bent at a right angle, and the risk of disconnection or breakage due to accumulated physical impact or fatigue during continuous use or handling is reduced.

[0067] However, the shape of the first lead coupling portion 211' is not limited to the above, and may be bent at an acute angle and / or an obtuse angle.

[0068] FIG. 12 is a plan view illustrating a battery cell according to another embodiment of the present invention, and FIG. 13 is a perspective view illustrating an example of a first electrode lead included in the battery cell of FIG. 12.

[0069] 12, a battery cell 10′ according to another embodiment of the present invention may include an electrode assembly 100, a first electrode lead 1210, and a second electrode lead 220. However, the battery cell 10′ may be substantially the same as the battery cell 10 described based on FIG. 1, except for the first electrode lead 1210.

[0070] 13, the first electrode lead 1210 may include a first lead coupling portion 1211 and a first extension portion 1212. The first lead coupling portion 1211 may be formed to wrap around at least a portion of the negative electrode tab laminate portion 112 and may be in contact with the negative electrode tab laminate portion 112. The first lead coupling portion 1211 may be shaped to protrude from a side surface of the first extension portion 1212. The first extension portion 1212 may extend from the first lead coupling portion 1211 to lead the negative electrode 110 to the outside of the battery cell 10′.

[0071] In one embodiment, the first lead coupling portion 1211 may include a top contact portion UC, a first side contact portion SC1, and a bottom contact portion LC.

[0072] The top surface contact portion UC may contact the top surface USF of the negative electrode tab stack portion 112. The first side surface contact portion SC1 may contact the first side surface SSF1 of the negative electrode tab stack portion 112. The bottom surface contact portion LC may contact the bottom surface LSF of the negative electrode tab stack portion 112.

[0073] For example, the first side surface SSF1 may be connected to the top surface USF, and the bottom surface LSF may be connected to the first side surface SSF1 and opposite to the top surface USF, so that the first lead coupling portion 1211 can contact the negative electrode tab stack portion 112 while continuously surrounding the top surface USF, the first side surface SSF1, and the bottom surface LSF.

[0074] In addition, the first lead coupling portion 1211 may expose the second side surface SSF2 and the back surface BSF of the negative electrode tab laminate portion 112. In this case, the second side surface SSF2 and the back surface BSF of the negative electrode tab laminate portion 112 exposed by the first lead coupling portion 1211 may not face the positive electrode tab laminate portion 122.

[0075] The battery cell 10' may include a negative electrode tab laminate 112 in which the negative electrode tabs 111 are aligned and laminated, and a first electrode lead 1210 connected to the negative electrode tab laminate 112. The first electrode lead 1210 may encase at least a portion of the negative electrode tab laminate 112, and for this purpose, the first electrode lead 1210 may include a top contact portion UC, a first side contact portion SC1, and a bottom contact portion LC. The first electrode lead 1210, which has a relatively high rigidity, is formed to encase the negative electrode tab laminate 112, which has a relatively low rigidity, so that in the process of joining the first electrode lead 1210 and the negative electrode tab laminate 112, the first electrode lead 1210 can prevent the negative electrode tab laminate 112 from breaking.

[0076] In addition, the first electrode lead 1210 may expose the second side surface SSF2 and the back surface BSF of the negative electrode tab laminate 112, and the second side surface SSF2 and the back surface BSF of the negative electrode tab laminate 112 may not face the positive electrode tab laminate 122. In the process of joining the first electrode lead 1210 and the negative electrode tab laminate 112, the contact portion between the first lead coupling portion 1210 and the negative electrode tab laminate 112 is crimped, and the negative electrode tab laminate 112 may expand while being restrained by the first lead coupling portion 1210. In other words, the negative electrode tab laminate 112 may be pushed toward the exposed second side surface SSF2 and back surface BSF, but may not be pushed by the top surface USF, the first side surface SSF1, and the bottom surface LSF covered by the first lead coupling portion 1210. This can prevent short circuits from occurring between the negative electrode tab laminate 112 and the surrounding electrodes (eg, the positive electrode tab laminate 122).

[0077] FIG. 14 is a perspective view illustrating a first electrode lead included in a battery cell according to yet another embodiment of the present invention.

[0078] 14, the first electrode lead 310 may include a first lead coupling portion 311 and a first extension portion 312. The first lead coupling portion 311 may be formed to wrap around at least a portion of the negative electrode tab laminate portion 112 and may be in contact with the negative electrode tab laminate portion 112. The first lead coupling portion 311 may be shaped to protrude from a side surface of the first extension portion 312. The first extension portion 312 may extend from the first lead coupling portion 311 to lead the negative electrode 110 to the outside of the battery cell.

[0079] In one embodiment, the first lead coupling portion 311 may include a top contact portion UC, a back contact portion BC, a first bottom contact portion LC1, and a second bottom contact portion LC2.

[0080] The top surface contact portion UC may contact the top surface USF of the negative electrode tab stack 112. The back surface contact portion BC may contact the back surface BSF of the negative electrode tab stack 112. The first bottom surface contact portion LC1 may contact the bottom surface LSF of the negative electrode tab stack 112. The second bottom surface contact portion LC2 may be in overall contact with the first bottom surface contact portion LC1 and connect the first bottom surface contact portion LC1 and the first extension portion 312. In other words, the first lead coupling portion 311 may be bent 180° from the bottom surface LSF. This improves the rigidity of the first lead coupling portion 311.

[0081] In addition, the first lead coupling portion 311 may expose the first side surface SSF1 and the second side surface SSF2 of the negative electrode tab laminate portion 112.

[0082] In this way, the first lead coupling part 311 contacts the top surface USF, back surface BSF, and bottom surface LSF of the negative electrode tab stacking part 112, so that the contact area is further increased compared to the conventional art, the resistance can be reduced, and improved bonding strength can be maintained. Since the first lead coupling part 311 contacts the top surface USF, back surface BSF, and bottom surface LSF of the negative electrode tab stacking part 112, it surrounds at least three surfaces of the negative electrode tab stacking part 112, so that it is possible to prevent the negative electrode tab stacking part 112 from breaking during welding, and therefore the safety of the negative electrode tab can be ensured.

[0083] FIG. 15 is a perspective view illustrating a first electrode lead included in a battery cell according to yet another embodiment of the present invention.

[0084] 15, the first electrode lead 410 may include a first lead coupling portion 411 and a first extension portion 412. The first lead coupling portion 411 may be formed to wrap around at least a portion of the negative electrode tab laminate portion 112 and may be in contact with the negative electrode tab laminate portion 112. The first lead coupling portion 411 may have a shape that protrudes from a side surface of the first extension portion 412. The first extension portion 412 may extend from the first lead coupling portion 411 to lead the negative electrode 110 to the outside of the battery cell.

[0085] In one embodiment, the first lead coupling portion 411 may include a top contact portion UC, a first side contact portion SC1, a second side contact portion SC2, and a bottom contact portion LC.

[0086] The top surface contact portion UC may contact the top surface USF of the negative electrode tab stack portion 112. The first side surface contact portion SC1 may contact the first side surface SSF1 of the negative electrode tab stack portion 112. The second side surface contact portion SC2 may contact the second side surface SSF2 of the negative electrode tab stack portion 112. The bottom surface contact portion LC may contact the bottom surface LSF of the negative electrode tab stack portion 112.

[0087] In addition, the first lead coupling portion 311 may expose the back surface BSF of the negative electrode tab laminate portion 112. In this case, the back surface BSF of the negative electrode tab laminate portion 112 exposed by the first lead coupling portion 311 may not face the positive electrode tab laminate portion 122, thereby preventing a short circuit between the negative electrode tab laminate portion 112 and a peripheral electrode (e.g., the positive electrode tab laminate portion 122).

[0088] That is, the first lead coupling part 311 contacts the top surface USF, the first side surface SSF1, the second side surface SSF2, and the bottom surface LSF of the negative electrode tab stacking part 112, and may be called a doughnut shape, and the contact area is further increased compared to the conventional case, so that the resistance can be reduced and improved bonding strength can be maintained. The negative electrode tab stacking part 112 can be positioned inside the doughnut-shaped first lead coupling part 311 and welded while being pressed against it. The space formed by the top contact portion UC, the first side contact portion SC1, the second side contact portion SC2, and the bottom contact portion LC of the first lead coupling portion 311 is even larger than the volume of the negative electrode tab stacking portion 112, so when the negative electrode tab stacking portion 112 is positioned inside the first lead coupling portion 311, there is ample space, making assembly easy, and when welding is performed while pressing, the space formed by the top contact portion UC, the first side contact portion SC1, the second side contact portion SC2, and the bottom contact portion LC of the first lead coupling portion 311 can be reduced, thereby strengthening the contact and coupling between the first lead coupling portion 311 and the negative electrode tab stacking portion 112.

[0089] The first lead coupling part 311 exposes the back surface BSF of the negative electrode tab lamination part 112 and surrounds four sides of the negative electrode tab lamination part 112, preventing breakage of the negative electrode tab lamination part 112 during welding, thereby ensuring the safety of the negative electrode tab. In addition, even if the negative electrode tab lamination part 112 is pressed during welding, the first lead coupling part 311 prevents contact with the surrounding electrodes, preventing a short circuit with the surrounding electrodes.

[0090] FIG. 16 is a perspective view illustrating a first electrode lead included in a battery cell according to yet another embodiment of the present invention.

[0091] 16, the first electrode lead 510 may include a first lead coupling portion 511 and a first extension portion 512. The first lead coupling portion 511 may be formed to wrap around at least a portion of the negative electrode tab laminate portion 112 and may be in contact with the negative electrode tab laminate portion 112. The first lead coupling portion 511 may be shaped to protrude from a side surface of the first extension portion 512. The first extension portion 512 may extend from the first lead coupling portion 511 to lead the negative electrode 110 to the outside of the battery cell.

[0092] In one embodiment, the first lead coupling portion 511 may include a top surface contact portion UC, a bottom surface contact portion LC, and a middle surface contact portion CC.

[0093] The top surface contact portion UC may contact the top surface USF of the negative electrode tab laminate 112. The bottom surface contact portion LC may contact the bottom surface LSF of the negative electrode tab laminate 112. The negative electrode tab laminate 112 may further include an intermediate surface CSF located between the top surface USF and the bottom surface LSF and parallel to the top surface USF and the bottom surface LSF, and the intermediate surface contact portion CC may contact the intermediate surface CSF. In other words, the intermediate surface contact portion CC may fit into the boundary of any one of the stacked negative electrode tabs 111. This makes it possible to electrically connect the negative electrode tab laminate 112 and the first lead coupling portion 311 more smoothly.

[0094] In addition, the first lead coupling portion 511 may expose the first side surface SSF1, the second side surface SSF2, and the back surface BSF of the negative electrode tab laminate portion 112.

[0095] The middle surface contact portion CC is fitted between the stacked negative electrode tabs 111, and the top surface contact portion UC and the bottom surface contact portion LC may be joined and welded after wrapping the outermost periphery of the negative electrode tab stacking portion 112. The contact area is further increased compared to the conventional art, so that the resistance can be reduced and improved joint strength can be maintained. Since the breakage of the negative electrode tab stacking portion 112 can be prevented during welding, the safety of the negative electrode tabs can be ensured. In addition, when the number of stacked negative electrode tabs 111 is large, the middle surface contact portion CC included in the first lead coupling portion 511 of this embodiment can further prevent detachment.

[0096] FIG. 17 is a diagram illustrating a battery module including a battery cell according to an embodiment of the present invention, and FIG. 18 is a diagram illustrating a battery pack including the battery module of FIG.

[0097] Referring to FIG. 17, a battery module BM may include at least one battery cell described with reference to FIGS. 1 to 16 and a module case MC accommodating the battery cell.

[0098] Small mobile devices use one or two to four battery cells per device, whereas medium to large devices such as automobiles require high output and large capacity. Therefore, medium to large battery modules including a cell stack in which a plurality of battery cells are electrically connected are used. A battery module BM manufactured by electrically connecting the battery cells 10 can be used as such a medium to large battery module. The battery cells 10 are connected to each other to ensure the required power for the application requiring the power of such a battery module BM.

[0099] Referring to FIG. 18, a battery pack BP may include at least one battery module BM described based on FIG. 17 and a pack case PC that packages the battery module BM.

[0100] The battery pack BP according to the present invention may further include various devices for controlling the charging and discharging of the battery module BM, such as a battery management system (BMS), a current sensor, a fuse, and the like. The BMS estimates the state of the cells in the battery pack BP and manages the battery pack BP using the estimated state information. For example, it estimates and manages state information of the battery pack BP, such as the state of charge (SOC), state of health (SOH), maximum input / output power allowance, output voltage, and the like. Then, using such state information, it is possible to control charging or discharging of the battery pack BP and further estimate the time to replace the battery pack BP.

[0101] The battery modules BM have a roughly rectangular parallelepiped shape and can be arranged in an orderly fashion within the pack case PC, and each battery module BM is connected to each other so as to ensure the required power to suit an application requiring the power of such a battery pack BP.

[0102] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the scope of the technical concept of the present invention and the scope of the claims. [Explanation of symbols]

[0103] 10, 10': Battery cell 100: Electrode assembly 110: Negative electrode 120: Positive electrode 111: Negative electrode tab 112: Negative electrode tab laminated section 210, 1210: first electrode lead 220: Second electrode lead 211, 1211: first lead connection part 212, 1212: first extension

Claims

1. an electrode assembly including an electrode tab stacking portion in which electrodes and electrode tabs protruding from the electrodes are aligned and stacked in a vertical direction; an electrode lead including a lead coupling portion that encases at least a portion of the electrode tab laminate; Including, a battery cell, wherein the lead coupling portion continuously surrounds and contacts a top surface of the electrode tab stacking portion, a first side surface connected to the top surface, and either a second side surface opposite the first side surface or a bottom surface opposite the top surface, and exposes the remaining other of the second side surface and the bottom surface opposite the top surface.

2. The electrode tab stacking portion has a back surface opposite to a protruding direction of the electrode tabs, The battery cell of claim 1 , wherein the lead bond portion exposes the back surface of the electrode tab stack.

3. The battery cell according to claim 1 , wherein a width of the lead coupling portion in a direction perpendicular to a protruding direction of the electrode tab is larger than a width of the electrode tab stacking portion in a direction perpendicular to the protruding direction of the electrode tab.

4. The battery cell according to claim 1 , wherein a height of the lead coupling portion in the vertical direction is greater than a height of the electrode tab stacking portion in the vertical direction.

5. The electrode lead further includes an extension portion extending from the lead coupling portion to lead the electrode to an outside of the battery cell, The battery cell according to claim 1 , wherein a width of the lead coupling portion in a direction perpendicular to a protruding direction of the electrode tab is larger than a width of the extension portion in the direction perpendicular to the protruding direction of the electrode tab.

6. The battery cell according to claim 5 , wherein the lead coupling portion is bent at a right angle from a corner portion where surfaces of the electrode tab laminated portion are connected to each other, and surrounds at least a portion of the electrode tab laminated portion.

7. The battery cell according to claim 5 , wherein the lead coupling portion is curved from a corner portion where surfaces of the electrode tab laminated portion are connected to each other, and surrounds at least a portion of the electrode tab laminated portion.

8. The battery cell according to claim 5 , wherein the lead coupling portion protrudes from a side surface of the extension portion.

9. The battery cell of claim 1 , wherein a stiffness of the lead bond portion is greater than a stiffness of the electrode tab.

10. 10. The battery cell of claim 9, wherein each of the electrode tabs is made of lithium metal.

11. The battery cell of claim 9 , wherein the lead joints are made of a metal other than lithium metal.

12. the electrode is a negative electrode, the electrode tab is a negative electrode tab and is made of lithium metal, and the electrode tab laminate is a negative electrode tab laminate; The electrode assembly further includes a positive electrode tab stacking part in which a positive electrode having a separator interposed between each of the negative electrodes and a positive electrode tab protruding from the positive electrode are aligned and stacked in a vertical direction, the positive electrode tab being made of a metal other than lithium metal, 2. The battery cell of claim 1, wherein the negative electrode tab laminate portion and the positive electrode tab laminate portion are formed side by side on one side of the electrode assembly, and the second side surface or the bottom surface of the negative electrode tab laminate portion exposed by the lead coupling portion does not face the positive electrode tab laminate portion.

13. The battery cell according to claim 12 , wherein a contact portion between the lead coupling portion and the negative electrode tab laminate portion is crimped, and the negative electrode tab laminate portion is expanded while being restrained by the lead coupling portion.

14. an electrode assembly including an electrode tab stacking portion in which electrodes and electrode tabs protruding from the electrodes are aligned and stacked in a vertical direction; an electrode lead including a lead coupling portion that encases at least a portion of the electrode tab laminate; Including, a first side surface connected to the top surface of the electrode tab stacking portion, a second side surface opposite to the first side surface, a bottom surface opposite to the top surface, and a back surface connected to the bottom surface and opposite to the protruding direction of the electrode tab.

15. The battery cell of claim 14 , wherein the lead coupling portion contacts the top surface, the back surface, and the bottom surface and exposes the first side surface and the second side surface.

16. The battery cell of claim 14 , wherein the lead coupling portion contacts the top surface, the first side surface, the second side surface, and the bottom surface and exposes the back surface.

17. The electrode tab stacking portion further defines an intermediate surface located between the top surface and the bottom surface and parallel to the top surface and the bottom surface, 15 . The battery cell of claim 14 , wherein the lead coupling portion contacts the top surface, the middle surface, and the bottom surface and exposes the first side surface, the second side surface, and the back surface.

18. At least one battery cell according to any one of claims 1 to 17; a module case that houses the at least one battery cell; a battery module.

19. At least one battery module according to claim 18; a pack case in which the at least one battery module is packaged; Including the battery pack.

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