Battery cells, battery modules containing battery cells, and battery packs containing 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 in which the shape of an electrode lead is improved. This application claims priority based on 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 all of the contents disclosed in the specifications and drawings of the applications are incorporated into this application.

Background Art

[0002] Secondary batteries, which are highly applicable depending on product groups and have electrical characteristics such as high energy density, are commonly applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source. Such secondary batteries not only have the temporary advantage of significantly reducing the use of fossil fuels but also have the advantage of not producing any by-products associated with the use of energy, and thus are attracting attention as a new energy source for environmental friendliness and energy efficiency improvement.

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

[0004] On the other hand, a battery cell includes electrodes (e.g., a negative electrode), and in order to lead the electrodes to the outside of the battery cell, electrode tabs (e.g., negative electrode tabs) protruding from the electrodes are joined to the electrode leads. Typically, electrode leads are manufactured in a plate shape and joined to the electrode tabs at the top surface of the electrode tabs. When the electrodes and electrode tabs are made of lithium metal, which has relatively low rigidity, the reliability of the electrode tabs may be a concern during the process of joining them using an ultrasonic method while pressing the electrode tabs and electrode leads together. For example, there is a risk that the electrode tabs may break in the area where the ultrasound is applied. There is also a concern that the electrode tabs may be pushed out, causing a short circuit with surrounding electrodes (e.g., other adjacent electrode tabs). Therefore, when joining the electrode tabs while maintaining the existing structure of the electrode leads, there is a high risk of defects occurring during the manufacture of secondary batteries such as lithium-sulfur batteries. [Overview of the project] [Problems that the invention aims to solve]

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

[0006] 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 the vertical direction, and an electrode lead including a lead coupling portion that encloses at least a part of the electrode tab stacking portion, wherein the lead coupling portion is in contact with the top surface of the electrode tab stacking portion, a first side surface connected to the top surface, and one of the second side surface opposite to the first side surface and the bottom surface opposite to the top surface, while continuously surrounding it, and the other of the second side surface and the bottom surface opposite to the top surface can be exposed.

[0007] In one embodiment, the electrode tab stacking portion is limited to a back surface opposite to the protruding direction of the electrode tabs, and the lead coupling portion can expose the back surface of the electrode tab stacking portion.

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

[0009] In one embodiment, the vertical height of the lead coupling portion may be even greater than the vertical height of the electrode tab stacking portion.

[0010] In one embodiment, the electrode lead further includes an extension that extends from the lead coupling portion and guides (leads) the electrode to the outside of the battery cell, wherein the width of the lead coupling portion in the direction perpendicular to the protruding direction of the electrode tab is even greater than the width of the extension portion in the direction perpendicular to the protruding direction of the electrode tab.

[0011] In one embodiment, the lead coupling portion can be bent at a right angle from a corner portion where the surfaces of the electrode tab stack are connected, thereby enclosing at least a part of the electrode tab stack.

[0012] In one embodiment, the lead coupling portion can be bent in a curved shape from a corner portion where the surfaces of the electrode tab stack are connected, thereby enclosing at least a part of the electrode tab stack.

[0013] In one embodiment, the lead coupling portion may have a shape that protrudes from the side surface of the extended portion.

[0014] In one embodiment, the rigidity of the lead coupling portion may be even greater than the rigidity 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 coupling portion 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 stack is a negative electrode tab stack, the electrode assembly further includes a positive electrode tab stack formed by stacking positive electrodes and positive electrode tabs protruding from the positive electrodes in an aligned vertical direction with a separator interposed between each of the negative electrodes, the positive electrode tab is made of a metal other than lithium metal, the negative electrode tab stack and the positive electrode tab stack are formed to be aligned with each other on one side of the electrode assembly, and the second side surface or bottom surface of the negative electrode tab stack exposed by the lead coupling portion does not necessarily have to face the positive electrode tab stack.

[0018] In one embodiment, the contact portion between the lead coupling portion and the negative electrode tab stack portion is compressed, allowing the negative electrode tab stack portion to expand while being constrained by the lead coupling portion.

[0019] A battery cell according to another aspect of the present invention includes an electrode assembly including an electrode tab stack portion in which electrodes and electrode tabs protruding from the electrodes are aligned and stacked vertically, and an electrode lead including a lead coupling portion that encloses at least a part of the electrode tab stack portion, wherein the lead coupling portion can expose at least one of the top surface of the electrode tab stack portion, a first side surface connected to the top surface, 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 direction in which the electrode tabs protrude.

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

[0022] The electrode tab stacking portion may have an intermediate surface located between the top surface and the bottom surface, parallel to the top surface and the bottom surface, and the lead coupling portion may be in contact with the top surface, the intermediate surface and the bottom surface, and expose the first side surface, the second side surface and the back surface.

[0023] To solve the above problems, the battery module and battery pack of the present invention may include a battery cell according to one embodiment of the present invention as described above. [Effects of the Invention]

[0024] The battery cell according to the present invention may include an electrode tab stacked portion in which electrode tabs are aligned and stacked, and an electrode lead connected to the electrode tab stacked portion. The electrode lead includes a lead coupling portion that wraps at least a part of the electrode tab stacked portion. For example, the electrode lead may contact the top surface, the first side surface, and the second side surface of the electrode tab stacked portion. By forming the relatively rigid electrode lead so as to wrap the relatively less rigid electrode tab stacked portion, in the process of joining the electrode lead and the electrode tab stacked portion, the electrode lead can prevent the electrode tab stacked portion from breaking.

[0025] Also, the electrode lead may expose the bottom surface and the back surface of the electrode tab stacked portion, and the bottom surface and the back surface of the electrode tab stacked portion may not face the peripheral electrodes. In the process of joining the electrode lead and the electrode tab stacked portion, the contact portion between the lead coupling portion and the electrode tab stacked portion is crimped, and the electrode tab stacked portion can expand in a state restrained by the lead coupling portion. In other words, although the electrode tab stacked portion may be pushed in the direction of the exposed bottom surface and back surface, it can be prevented from being pushed against the top surface, the first side surface, and the second side surface covered by the lead coupling portion. Thereby, a short circuit between the electrode tab stacked portion and the peripheral electrodes can be prevented from occurring.

[0026] In addition to the above, in the battery cell according to another aspect of the present invention, the lead coupling portion may expose at least any one of the top surface, the first side surface, the second side surface, the bottom surface, and the back surface of the electrode tab stacked portion. Compared with the case where a conventional electrode lead is joined to an electrode tab on the top surface of the electrode tab, according to another aspect of the present invention, the joining area increases.

[0027] Thus, since the electrode lead wraps around at least a part of the electrode tab laminated portion, not only can the joining safety between the electrode tab and the electrode lead be ensured, but also the joining area between the electrode tab and the electrode lead can be increased, the joining strength can be improved, and moreover, the contact resistance can be reduced. Since the shape in which the electrode lead wraps around at least a part of the electrode tab laminated portion can be maintained even during use, there is an effect that the current can be easily moved by maintaining the improved joining strength.

[0028] The following drawings attached to this specification illustrate desirable embodiments of the present invention and are for the purpose of further understanding the technical idea of the present invention together with the content of the invention. Therefore, the present invention is not construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0029] [Figure 1] It is a plan view for explaining a battery cell according to an embodiment of the present invention. [Figure 2] It is a perspective view for explaining an example of a first electrode lead included in the battery cell of FIG. 1. [Figure 3] It is a cross-sectional view taken along the line A-A' of FIG. 1. [Figure 4] It is a cross-sectional view taken along the line B-B' of FIG. 1. [Figure 5] It is a cross-sectional view taken along the line C-C' of FIG. 1. [Figure 6] It is a perspective view for explaining an example of a method for manufacturing the battery cell of FIG. 1. [Figure 7] It is a perspective view for explaining an example of a method for manufacturing the battery cell of FIG. 1. [Figure 8] It is a perspective view for explaining an example of a method for manufacturing the battery cell of FIG. 1. [Figure 9] It is a perspective view for explaining another example of a method for manufacturing the battery cell of FIG. 1. [Figure 10]Figure 1 is a perspective view illustrating another example of a method for manufacturing battery cells. [Figure 11] This is a perspective view illustrating another example of the first electrode lead included in the battery cell shown in Figure 1. [Figure 12] This is a plan view illustrating a battery cell according to another embodiment of the present invention. [Figure 13] Figure 12 is a perspective view illustrating an example of a first electrode lead included in a battery cell. [Figure 14] This 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] This 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] This 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] This is a diagram illustrating a battery module including a battery cell according to one embodiment of the present invention. [Figure 18] This diagram illustrates the battery pack, including the battery module shown in Figure 17. [Modes for carrying out the invention]

[0030] The present invention will become even clearer by describing preferred embodiments of the invention in detail with reference to the accompanying 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 ways different from the embodiments described herein. In addition, for the purpose of aiding in understanding the invention, the accompanying drawings are not shown to actual scale, and the dimensions of some components may be exaggerated.

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

[0032] First, referring to Figure 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 stacked portion 112, and a positive electrode tab stacked portion 122.

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

[0035] In one embodiment, referring to Figure 3, the negative electrode tab 111 may protrude from the negative electrode 110 in a first direction D1 (e.g., the protruding direction). The negative electrode tabs 111 may also be stacked in a third direction D3 (e.g., the vertical direction). The negative electrode tab stacked 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 tab may protrude from the positive electrode 120 in a first direction D1. Alternatively, the positive electrode tab may 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] In one embodiment, as shown in Figure 1, the negative electrode tab stack 112 and the positive electrode tab stack 122 may be formed so as to be aligned with each other on one side of the electrode assembly 100. Alternatively, the negative electrode tab stack 112 and the positive electrode tab stack 122 may be formed so as to be spaced apart from each other. This makes it possible for the first electrode lead 210 and the second electrode lead 220 to be arranged so as 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 realizing a lithium-sulfur battery, and the positive electrode 120 may be coated with a positive electrode active material containing a sulfur compound.

[0039] The first electrode lead 210 can be electrically connected to the electrode assembly 100 via the negative electrode tab stack 112. For example, the first electrode lead 210 can be joined to the negative electrode tab stack 112. The first electrode lead 210 can be joined to the negative electrode tab stack 112 using known joining methods. For example, the first electrode lead 210 can be joined to the negative electrode tab stack 112 using a pressure bonding method, an ultrasonic bonding method, a resistance bonding method, a laser bonding method, etc. As a result, the first electrode lead 210 can come into contact with the negative electrode tab stack 112 and lead the negative electrode 110 to the outside of the battery cell 10. Thus, the first electrode lead 210 can be a negative electrode lead.

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

[0041] In one embodiment, the rigidity of the first electrode lead 210 may be even greater than that 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, thereby compensating for the properties of the negative electrode tab 111, which may be made of lithium metal.

[0042] A battery cell 10 according to one embodiment of the present invention includes a particularly improved first electrode lead 210. The first electrode lead 210 will be described in more detail with reference to Figures 2 to 5.

[0043] Referring to Figures 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 is formed to enclose at least a portion of the negative electrode tab stack portion 112 and may contact the negative electrode tab stack portion 112. The first lead coupling portion 211 may be shaped to protrude from the side of the first extension portion 212. The first extension portion 212 may extend from the first lead coupling portion 211 and 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 contact portion UC, a first side contact portion SC1, and a second side contact portion SC2.

[0045] The top contact portion UC may contact the top surface USF of the negative electrode tab stacking portion 112. The first side contact portion SC1 may contact the first side surface SSF1 of the negative electrode tab stacking portion 112. The second side contact portion SC2 may contact the second side surface SSF2 of the negative electrode tab stacking 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 opposite to the first side surface SSF1. This allows the first lead coupling portion 211 to 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 two surfaces of the negative electrode tab stack 112 are connected, thereby enclosing at least a portion of the negative electrode tab stack 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 of the negative electrode tab stack 112 is connected to the first side surface SSF1 (for example, the portion where the top surface contact portion UC is connected to the first side surface contact portion SC1). Alternatively, the first lead coupling portion 211 may be bent at a right angle from a corner portion where the top surface USF of the negative electrode tab stack 112 is connected to the second side surface SSF2 (for example, the portion where the top surface contact portion UC is connected to the second side surface contact portion SC2).

[0048] In one embodiment, the first lead coupling portion 211 may have a first width W1 in a direction perpendicular to the protruding direction of the negative electrode tab 111 (for example, a second direction D2), and the negative electrode tab stacking portion 112 may have a second width W2 in the same direction perpendicular to the protruding direction of the negative electrode tab 111 (for example, a second direction D2). In this case, the first width W1 may be even larger than the second width W2, so that the first lead coupling portion 211 can sufficiently enclose the negative electrode tab stacking 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 it may be larger than the width of the negative electrode tab stacked portion 112.

[0050] In one embodiment, the first lead coupling portion 211 may have a first height H1 in the vertical direction (for example, a third direction D3), and the negative electrode tab stacking portion 112 may have a second height H2 in the vertical direction (for example, a third direction D3). In this case, the first height H1 may be even greater than the second height H2, thereby allowing the first lead coupling portion 211 to sufficiently enclose the negative electrode tab stacking portion 112.

[0051] Furthermore, the first lead coupling portion 211 may expose the bottom LSF and rear BSF of the negative electrode tab stack portion 112. For example, the bottom LSF may be opposite to the top USF and connected to the first and second side SSF1 and SSF2. The rear BSF may be opposite to the protruding direction of the negative electrode tab 111 (for example, the first direction D1).

[0052] The first extension 212 may extend from the first lead coupling 211. The first extension 212 may lead the negative electrode 110 to the outside of the battery cell 10. In one embodiment, as shown in Figure 2, the first extension 212 may extend from the top of the first lead coupling 211. For example, the first extension 212 may be formed integrally with the first lead coupling 211. However, the present invention is not limited thereto, and the first extension 212 may also extend from the middle or bottom of the first lead coupling 211.

[0053] The battery cell 10 may include a negative electrode tab stack 112 formed by aligning and stacking negative electrode tabs 111, and a first electrode lead 210 connected to the negative electrode tab stack 112. The first electrode lead 210 may enclose at least a portion of the negative electrode tab stack 112, and for this purpose, the first electrode lead 210 may include a top contact portion UC, a first side contact portion SC1, and a second side contact portion SC2. By forming the relatively rigid first electrode lead 210 to enclose the relatively less rigid negative electrode tab stack 112, the first electrode lead 210 can prevent the negative electrode tab stack 112 from breaking during the joining process between the first electrode lead 210 and the negative electrode tab stack 112.

[0054] Furthermore, the first electrode lead 210 may expose the bottom LSF and back BSF of the negative electrode tab stack 112, and the bottom LSF and back BSF of the negative electrode tab stack 112 do not necessarily face the positive electrode tab stack 122. During the process of joining the first electrode lead 210 and the negative electrode tab stack 112, the contact portion between the first lead coupling portion 211 and the negative electrode tab stack 112 is compressed, and the negative electrode tab stack 112 can expand while being constrained by the first lead coupling portion 211. In other words, although the negative electrode tab stack 112 may be pushed in the direction of the exposed bottom LSF and back BSF, it can not be pushed by the top USF, the first side SSF1, and the second side SSF2 which are covered by the first lead coupling portion 211. This prevents short circuits from occurring between the negative electrode tab stacking portion 112 and the surrounding electrodes (for example, the positive electrode tab stacking portion 122).

[0055] Figures 6 to 8 are perspective views illustrating an example of a method for manufacturing the battery cell shown in Figure 1.

[0056] Referring to Figure 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 first lead coupling portion 211 described above, and may be flat so as to be parallel to the planes 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 greater than the width PW2 of the first extension portion 212.

[0057] Referring to Figure 7, the spare first electrode lead P210 and the negative electrode tab stack 112 are close to each other, and a portion of the spare first lead coupling portion P211 may come into contact with the negative electrode tab stack 112. For example, the portion of the spare first lead coupling portion P211 may come into contact with the uppermost negative electrode tab among the negative electrode tabs 111 aligned in the negative electrode tab stack 112.

[0058] Referring to Figure 8, the spare first lead connector P211 can be bent to correspond to the shape of the negative electrode tab stack 112. For example, the spare first lead connector P211 can be bent and joined to the negative electrode tab stack 112 using one of the joining methods described above. This makes it possible for the first lead connector 211 to be formed to enclose at least a portion of the negative electrode tab stack 112.

[0059] According to the manufacturing method described above based on Figures 6 to 8, a flat, preliminary first lead connector P211 can be brought into contact with the negative electrode tab stack 112, and then bent to match the shape of the negative electrode tab stack 112 to form the first lead connector 211. This increases the contact area between the first lead connector 211 and the negative electrode tab stack 112, thereby reducing the electrical resistance between the first lead connector 211 and the negative electrode tab stack 112. Furthermore, the negative electrode tab 111 is pressed against the bottom LSF and / or back BSF of the negative electrode tab stack 112 that do not face the surrounding electrodes, preventing a short circuit between the negative electrode tab stack 112 and the surrounding electrodes (e.g., the positive electrode tab stack 122).

[0060] Figures 9 and 10 are perspective views illustrating other examples of the method for manufacturing the battery cell shown in Figure 1.

[0061] Referring to Figure 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 Figure 2. In other words, the first electrode lead 210 may be pre-formed to enclose at least a portion of the negative electrode tab stacked portion 112, corresponding to the shape of the negative electrode tab stacked 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 Figure 10, as the first electrode lead 210 and the negative electrode tab stacked portion 112 move closer to each other and are pressed against one another, the top contact portion UC, the first side contact portion SC1, and the second side contact portion SC2 of the first lead coupling portion 211 can come into contact with the negative electrode tab stacked portion 112.

[0063] According to the manufacturing method described above based on Figures 9 and 10, the first electrode lead 210 can be pre-formed to correspond to the shape of the negative electrode tab laminated portion 112. This improves the productivity of the joining process between the first electrode lead 210 and the negative electrode tab laminated portion 112, and relatively reduces the phenomenon of the negative electrode tab 111 being pressed.

[0064] Figure 11 is a perspective view illustrating another example of the first electrode lead included in the battery cell of Figure 1.

[0065] Referring to Figure 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 contact portion UC', a first side contact portion SC1', and a second side contact portion SC2'. However, the first electrode lead 210' may have substantially the same shape as the first electrode lead 210 described above based on Figure 2, except for the shape of the corner portion which will be described later.

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

[0067] However, the shape of the first lead coupling portion 211' is not limited to what has been described above, such as the first lead coupling portion 211' being bent at an acute angle and / or an obtuse angle.

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

[0069] Referring to Figure 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 identical to the battery cell 10 described with reference to Figure 1, except for the first electrode lead 1210.

[0070] Referring to Figure 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 is formed to enclose at least a portion of the negative electrode tab stack portion 112 and may contact the negative electrode tab stack portion 112. The first lead coupling portion 1211 may be shaped to protrude from the side of the first extension portion 1212. The first extension portion 1212 may extend from the first lead coupling portion 1211 and 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 contact portion UC may contact the top surface USF of the negative electrode tab stacking portion 112. The first side contact portion SC1 may contact the first side surface SSF1 of the negative electrode tab stacking portion 112. The bottom contact portion LC may contact the bottom surface LSF of the negative electrode tab stacking 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. This allows the first lead coupling portion 1211 to 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] Furthermore, the first lead coupling portion 1211 may expose the second side SSF2 and back BSF of the negative electrode tab stacking portion 112. In this case, the second side SSF2 and back BSF of the negative electrode tab stacking portion 112 exposed by the first lead coupling portion 1211 do not necessarily face the positive electrode tab stacking portion 122.

[0075] The battery cell 10' may include a negative electrode tab stack 112 formed by aligning and stacking negative electrode tabs 111, and a first electrode lead 1210 connected to the negative electrode tab stack 112. The first electrode lead 1210 may enclose at least a portion of the negative electrode tab stack 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. By forming the relatively rigid first electrode lead 1210 to enclose the relatively less rigid negative electrode tab stack 112, the first electrode lead 1210 can prevent the negative electrode tab stack 112 from breaking during the joining process between the first electrode lead 1210 and the negative electrode tab stack 112.

[0076] Furthermore, the first electrode lead 1210 may expose the second side surface SSF2 and back surface BSF of the negative electrode tab laminate 112, and the second side surface SSF2 and back surface BSF of the negative electrode tab laminate 112 do not necessarily face the positive electrode tab laminate 122. During 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 compressed, and the negative electrode tab laminate 112 can expand while being constrained by the first lead coupling portion 1210. In other words, although the negative electrode tab laminate 112 may be pushed in the direction of the exposed second side surface SSF2 and back surface BSF, it can 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 prevents short circuits from occurring between the negative electrode tab stacking portion 112 and the surrounding electrodes (for example, the positive electrode tab stacking portion 122).

[0077] Figure 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] Referring to Figure 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 is formed to enclose at least a portion of the negative electrode tab stack portion 112 and may contact the negative electrode tab stack portion 112. The first lead coupling portion 311 may be shaped to protrude from the side of the first extension portion 312. The first extension portion 312 may extend from the first lead coupling portion 311 and 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 contact portion UC may contact the top surface USF of the negative electrode tab stack portion 112. The back contact portion BC may contact the back surface BSF of the negative electrode tab stack portion 112. The first bottom contact portion LC1 may contact the bottom surface LSF of the negative electrode tab stack portion 112. The second bottom contact portion LC2 may contact the first bottom contact portion LC1 overall and connect the first bottom 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] Furthermore, the first lead coupling portion 311 can expose the first side surface SSF1 and the second side surface SSF2 of the negative electrode tab stacked portion 112.

[0082] As described above, the first lead coupling portion 311 is in contact with the top surface USF, back surface BSF, and bottom surface LSF of the negative electrode tab laminated portion 112, so the contact area is further increased compared to the conventional method, reducing resistance and maintaining improved bonding strength. Since the first lead coupling portion 311 is in contact with the top surface USF, back surface BSF, and bottom surface LSF of the negative electrode tab laminated portion 112, it surrounds at least three sides of the negative electrode tab laminated portion 112, preventing fracture of the negative electrode tab laminated portion 112 during welding, thereby ensuring the safety of the negative electrode tab.

[0083] Figure 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] Referring to Figure 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 is formed to enclose at least a portion of the negative electrode tab stack portion 112 and may contact the negative electrode tab stack portion 112. The first lead coupling portion 411 may be shaped to protrude from the side of the first extension portion 412. The first extension portion 412 may extend from the first lead coupling portion 411 and 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 contact portion UC may contact the top surface USF of the negative electrode tab stacking portion 112. The first side contact portion SC1 may contact the first side surface SSF1 of the negative electrode tab stacking portion 112. The second side contact portion SC2 may contact the second side surface SSF2 of the negative electrode tab stacking portion 112. The bottom contact portion LC may contact the bottom surface LSF of the negative electrode tab stacking portion 112.

[0087] Furthermore, the first lead coupling portion 311 can expose the back surface shield (BSF) of the negative electrode tab stack portion 112. In this case, the back surface BSF of the negative electrode tab stack portion 112 exposed by the first lead coupling portion 311 does not have to face the positive electrode tab stack portion 122, thereby preventing a short circuit between the negative electrode tab stack portion 112 and the surrounding electrodes (for example, the positive electrode tab stack portion 122).

[0088] In other words, the first lead coupling portion 311 is in contact with the top surface USF, the first side surface SSF1, the second side surface SSF2, and the bottom surface LSF of the negative electrode tab stacked portion 112, which can be called a so-called donut shape. The contact area is further increased compared to conventional methods, reducing resistance and maintaining improved bonding strength. The negative electrode tab stacked portion 112 can be positioned inside the donut-shaped first lead coupling portion 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 stack portion 112. Therefore, when positioning the negative electrode tab stack portion 112 inside the first lead coupling portion 311, there is sufficient space for easy assembly. Furthermore, when welding 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 connection between the first lead coupling portion 311 and the negative electrode tab stack portion 112.

[0089] The first lead coupling portion 311 exposes the back BSF of the negative electrode tab stack 112 and surrounds all four sides of the negative electrode tab stack 112, thereby preventing the negative electrode tab stack 112 from breaking during welding and ensuring the safety of the negative electrode tab. Furthermore, even if the negative electrode tab stack 112 is pressed during welding, the first lead coupling portion 311 prevents contact with the surrounding electrodes, thus preventing short circuits with the surrounding electrodes.

[0090] Figure 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] Referring to Figure 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 is formed to enclose at least a portion of the negative electrode tab stack portion 112 and may contact the negative electrode tab stack portion 112. The first lead coupling portion 511 may be shaped to protrude from the side of the first extension portion 512. The first extension portion 512 may extend from the first lead coupling portion 511 and 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 contact portion UC, a bottom contact portion LC, and an intermediate contact portion CC.

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

[0094] Furthermore, the first lead coupling portion 511 can expose the first side surface SSF1, the second side surface SSF2, and the back surface BSF of the negative electrode tab stacked portion 112.

[0095] The intermediate surface contact portion CC is fitted between the stacked negative electrode tabs 111, and the top surface contact portion UC and bottom surface contact portion LC enclose the outermost edge of the negative electrode tab stack 112 before joining and welding can be performed. The contact area can be further increased compared to conventional methods, reducing resistance and maintaining improved joint strength. Breakage of the negative electrode tab stack 112 can be prevented during welding, thus ensuring the safety of the negative electrode tabs. In addition, when there are many stacks of negative electrode tabs 111, the intermediate surface contact portion CC included in the first lead coupling portion 511 of this embodiment can further prevent detachment.

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

[0097] Referring to Figure 17, the battery module BM may include at least one battery cell and a module case MC housing the battery cell, as described based on Figures 1 to 16.

[0098] Small mobile devices use one or two to four battery cells per device, while medium- and large-sized devices such as automobiles require high output and high capacity. Therefore, medium- and large-sized battery modules are used, which consist of a cell stack in which multiple battery cells are electrically connected. A battery module BM manufactured by electrically connecting battery cells 10 can be used as such a medium- and large-sized battery module. Each battery cell 10 is connected to one another in such a way that it can secure the required power to suit the application that requires the power of such a battery module BM.

[0099] Referring to Figure 18, the battery pack BP may include at least one battery module BM and a pack case PC for packaging the battery module BM, as described based on Figure 17.

[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), current sensors, and fuses. The BMS estimates the state of the cells within 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 capacity, and output voltage. Using this state information, it controls the charging or discharging of the battery pack BP and can even estimate when the battery pack BP needs to be replaced.

[0101] The battery modules BM have a roughly rectangular shape and can be neatly arranged inside the PC case. Each battery module BM is connected to the others to ensure that it has the necessary power to suit the application that requires power from such a battery pack BP.

[0102] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and that various modifications and variations can be made by persons with ordinary skill in the art to which the present invention pertains, within the equivalent scope of the technical concept and claims of the present invention. [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 212, 1212: First extension

Claims

1. An electrode assembly including an electrode and an electrode tab stacking section in which electrode tabs protruding from the electrode are aligned and stacked in the vertical direction, An electrode lead including a lead coupling portion that contacts at least a part of the electrode tab stacked portion, Includes, The lead coupling portion is in contact with the top surface of the electrode tab stacking portion, the first side surface connected to the top surface, and one of the second side surface opposite to the first side surface and the bottom surface opposite to the top surface, while continuously surrounding them, and the other of the second side surface and the bottom surface opposite to the top surface is exposed. Each of the electrode tabs is made of lithium metal, forming a battery cell.

2. The electrode tab stacking portion has a back surface that is in the direction of protrusion of the electrode tabs, The battery cell according to claim 1, wherein the lead coupling portion exposes the back surface of the electrode tab stacking portion.

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

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

5. The electrode lead further includes an extended portion that extends from the lead coupling portion and guides the electrode to the outside of the battery cell, The battery cell according to claim 1, wherein the width of the lead coupling portion in the direction perpendicular to the protruding direction of the electrode tab is greater than the width of the extended portion in the direction perpendicular to the protruding direction of the electrode tab.

6. The battery cell according to claim 5, wherein the lead connecting portion is bent at a right angle from the corner portion where the surfaces of the electrode tab stack are connected and encloses at least a part of the electrode tab stack.

7. The battery cell according to claim 5, wherein the lead connecting portion is bent in a curved shape from the corner portion where the surfaces of the electrode tab stack are connected and encloses at least a part of the electrode tab stack.

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

9. The battery cell according to claim 1, wherein the lead coupling portion is made of a metal other than lithium metal.

10. The electrode is a negative electrode, the electrode tab is a negative electrode tab, and is made of lithium metal, and the electrode tab stack is a negative electrode tab stack. The electrode assembly further includes a positive electrode tab stacking section in which positive electrodes with a separator interposed between each of the negative electrodes and positive electrode tabs protruding from the positive electrodes are aligned and stacked vertically, and the positive electrode tabs are made of a metal other than lithium metal. The battery cell according to claim 1, wherein the negative electrode tab stack and the positive electrode tab stack are formed so as 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 stack exposed by the lead coupling portion does not face the positive electrode tab stack.

11. The battery cell according to claim 10, wherein the contact portion between the lead coupling portion and the negative electrode tab stack portion is crimped together.

12. An electrode assembly including an electrode and an electrode tab stacking section in which electrode tabs protruding from the electrode are aligned and stacked in the vertical direction, An electrode lead including a lead coupling portion that contacts at least a part of the electrode tab stacked portion, Includes, The lead coupling portion exposes at least one of the following: the top surface of the electrode tab stacking portion, a first side surface connected to the top surface, 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 facing the direction of protrusion of the electrode tab, in a battery cell. The lead coupling portion is in contact with the top surface, the back surface, and the bottom surface, and exposes the first side surface and the second side surface. Each of the electrode tabs is made of lithium metal, forming a battery cell.

13. An electrode assembly including an electrode and an electrode tab stacking section in which electrode tabs protruding from the electrode are aligned and stacked in the vertical direction, An electrode lead including a lead coupling portion that contacts at least a part of the electrode tab stacked portion, Includes, The lead coupling portion exposes at least one of the following: the top surface of the electrode tab stacking portion, a first side surface connected to the top surface, 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 facing the direction of protrusion of the electrode tab, in a battery cell. The lead coupling portion is in contact with the top surface, the first side surface, the second side surface, and the bottom surface, and the back surface is exposed. Each of the electrode tabs is made of lithium metal, forming a battery cell.

14. An electrode assembly including an electrode and an electrode tab stacking section in which electrode tabs protruding from the electrode are aligned and stacked in the vertical direction, An electrode lead including a lead coupling portion that contacts at least a part of the electrode tab stacked portion, Includes, The lead coupling portion exposes at least one of the following: the top surface of the electrode tab stacking portion, a first side surface connected to the top surface, 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 facing the direction of protrusion of the electrode tab, in a battery cell. The electrode tab stacking portion further has an intermediate surface located between the top surface and the bottom surface, which is parallel to the top surface and the bottom surface. The lead connection portion is in contact with the top surface, the middle surface, and the bottom surface, and the first side surface, the second side surface, and the back surface are exposed in the battery cell.

15. A battery cell according to any one of claims 1 to 14, A module case housing at least one of the aforementioned battery cells, A battery module, including the battery module.

16. At least one battery module according to claim 15, A pack case containing at least one of the aforementioned battery modules, A battery pack, including the battery pack.

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