CN118176623A

CN118176623A - Battery cell, battery module including the same, and battery pack including the battery module

Info

Publication number: CN118176623A
Application number: CN202380014184.4A
Authority: CN
Inventors: 朴奇秀; 李载佶; 申东析
Original assignee: LG Energy Solution Ltd
Current assignee: LG Energy Solution Ltd
Priority date: 2022-08-31
Filing date: 2023-07-07
Publication date: 2024-06-11

Abstract

Provided are a battery cell capable of preventing damage to an electrode tab protruding from an electrode, preventing a short circuit between the electrode tab and a surrounding electrode, and reducing resistance between the electrode tab and an electrode lead, and a battery module and a battery pack each including the battery cell. The battery cell according to the present disclosure includes: an electrode assembly including an electrode and an electrode tab stacking unit in which electrode tabs protruding from the electrode are aligned and the aligned electrode tabs are vertically stacked; and an electrode lead including a lead coupling unit surrounding at least a portion of the electrode tab stacking unit, wherein the lead coupling unit contacts while continuously surrounding one of a top surface of the electrode tab stacking unit, a first side surface connected to the top surface, 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

Battery cell, battery module including the same, and battery pack including the battery module

Technical Field

The present disclosure 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 electrode lead shape. The present application claims priority from korean patent application No. 10-2022-0110396, filed on 8.31 of 2022, and korean patent application No. 10-2022-0152044, filed on 11.14 of 2022, the disclosures of which are incorporated herein by reference.

Background

Secondary batteries have high applicability according to product groups and electrical characteristics (e.g., high energy density), and thus are generally applied not only to portable devices, but also to Electric Vehicles (EVs) or Hybrid Electric Vehicles (HEVs) driven by electric power sources. These secondary batteries are attracting attention as a new energy source for improving the eco-friendliness and energy efficiency because it not only has the main advantage of significantly reducing the use of fossil fuel, but also does not generate byproducts due to the use of energy.

Secondary batteries that are widely used at present include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and the like. For example, a lithium ion battery may be formed by applying a positive electrode active material (e.g., lithium composite transition metal oxide) to a positive electrode current collector and a negative electrode active material (e.g., carbon material) to a negative electrode current collector (e.g., copper, stainless steel, aluminum, nickel, carbon, etc.). In recent years, lithium sulfur batteries that may replace lithium ion batteries have been attracting attention as next-generation secondary batteries. By using a sulfur-based compound as a positive electrode active material and an alkali metal such as lithium metal as a negative electrode, a lithium sulfur battery can have a higher energy density than a conventional lithium secondary battery.

Meanwhile, the battery cell includes an electrode (e.g., a negative electrode), and in order to guide the electrode to the outside of the battery cell, an electrode tab (e.g., a negative electrode tab) protruding from the electrode is used by being coupled to an electrode lead. Typically, the electrode leads are manufactured in a plate shape and are bonded to the electrode tabs on the upper surfaces of the electrode tabs. If the electrode and the electrode tab are made of lithium metal having relatively low rigidity, reliability of the electrode tab may be problematic in the process of ultrasonically bonding the electrode tab and the electrode lead under compression. For example, the electrode tab may be damaged in a region where ultrasonic waves are applied. In addition, the electrode tabs may be pushed out to cause shorting to surrounding electrodes (e.g., other adjacent electrode tabs). Accordingly, when the existing structure of the electrode lead is maintained and the electrode lead is coupled to the electrode tab, there is a high risk of occurrence of defects during manufacturing of the secondary battery such as a lithium sulfur battery.

Disclosure of Invention

Technical problem

The present disclosure is designed to solve the problems of the prior art, and therefore, it is an object of the present disclosure to provide a battery cell capable of preventing damage of an electrode tab protruding from an electrode, preventing a short circuit between the electrode tab and a surrounding electrode, and reducing resistance between the electrode tab and an electrode lead, and a battery module and a battery pack including the same.

Technical proposal

According to an aspect of the present disclosure, a battery cell for solving the above-described problems may include: an electrode assembly including an electrode and an electrode tab stacking portion in which electrode tabs protruding from the electrode are aligned and stacked in a vertical direction; and an electrode lead including a lead coupling portion surrounding at least a portion of the electrode tab stacking portion, wherein the lead coupling portion may continuously surround and contact any one of an upper surface of the electrode tab stacking portion, a first side surface connected to the upper surface, a second side surface opposite to the first side surface, and a lower surface opposite to the upper surface, and the other one of the second side surface and the lower surface opposite to the upper surface may be exposed.

In one embodiment, the electrode tab stacking portion may have a back surface defined opposite to a protruding direction of the electrode tab, wherein the lead coupling portion may expose the back surface of the electrode tab stacking portion.

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

In one embodiment, wherein 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.

In one embodiment, the electrode lead may further include an extension portion extending from the lead coupling portion to guide the electrode to the outside of the battery cell, wherein a width of the lead coupling 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.

In one embodiment, the lead coupling portion may be bent at a right angle at a corner portion where one surface of the electrode tab stacking portion is connected to the other surface thereof to surround at least a portion of the electrode tab stacking portion.

In one embodiment, the lead coupling portion may be bent into a curved shape at a corner portion where one surface of the electrode tab stacking portion is connected to the other surface thereof to surround at least a portion of the electrode tab stacking portion.

In one embodiment, the wire coupling portion may have a shape protruding from a side surface of the extension portion.

In one embodiment, the lead coupling portion may have a rigidity greater than that of the electrode tab.

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

In one embodiment, the lead coupling portion may be made of a metal different from lithium metal.

In one embodiment, the electrode may be a negative electrode, the electrode tabs may be negative electrode tabs and be made of lithium metal, and the electrode tab stacking portion may be a negative electrode tab stacking portion, wherein the electrode assembly may further include a positive electrode in which a separator is interposed between each of the negative electrodes and the positive electrode tab stacking portion, positive electrode tabs protruding from the positive electrode are aligned and stacked in the vertical direction, and the positive electrode tabs may be made of metal other than lithium metal, wherein the negative electrode tab stacking portion and the positive electrode tab stacking portion may be formed parallel to each other on one side of the electrode assembly, and the second side surface or the lower surface of the negative electrode tab stacking portion exposed through the lead coupling portion may not face the positive electrode tab stacking portion.

In one embodiment, the contact portions of the lead coupling portion and the negative electrode tab stacking portion may be compressed such that the negative electrode tab stacking portion may be expanded while being restrained by the lead coupling portion.

According to another aspect of the present disclosure, a battery cell may include: an electrode assembly including an electrode and an electrode tab stacking portion in which electrode tabs protruding from the electrode are aligned and stacked in a vertical direction; and an electrode lead including a lead coupling portion surrounding at least a portion of the electrode tab stacking portion, wherein the lead coupling portion may expose at least one of an upper surface of the electrode tab stacking portion, a first side surface connected to the upper surface, a second side surface opposite to the first side surface, a lower surface opposite to the upper surface, and a back surface connected to the lower surface and opposite to a protruding direction of the electrode tab.

The wire coupling portion may contact the upper surface, the back surface, and the lower surface, and may expose the first side surface and the second side surface.

The wire coupling portion may contact the upper surface, the first side surface, the second side surface, and the lower surface, and may expose a back surface. The electrode tab stacking portion may have a central surface further defined to be located between and parallel to the upper and lower surfaces, wherein the lead coupling portion may contact the upper, central, and lower surfaces and may expose the first side surface, the second side surface, and the back surface.

The battery module and the battery pack of the present disclosure for solving the above-described problems may include the battery cells according to the embodiments of the present disclosure as described above.

Advantageous effects

The battery cell according to the present disclosure may include: an electrode tab stacking portion in which the electrode tabs are aligned and stacked; and an electrode lead connected to the electrode tab stacking portion. The electrode lead includes a lead coupling portion surrounding at least a portion of the electrode tab stacking portion, and for example, the electrode lead may contact an upper surface, a first side surface, and a second side surface of the electrode tab stacking portion. Since the electrode lead having a relatively large rigidity is formed to surround the electrode tab stacking part having a relatively small rigidity, the electrode lead can prevent damage of the electrode tab stacking part during the bonding of the electrode lead and the electrode tab stacking part.

In addition, the electrode leads may expose the lower and rear surfaces of the electrode tab stack portion, and the lower and rear surfaces of the electrode tab stack portion may not face the surrounding electrode. In the process of bonding the electrode lead and the electrode tab stacking portion, the contact portions of the lead coupling portion and the electrode tab stacking portion may be compressed so that the electrode tab stacking portion may be unfolded while being restrained by the lead coupling portion. In other words, the electrode tab stacking portion may be pushed toward the exposed lower and back surfaces, but not toward the upper, first and second side surfaces covered by the wire coupling portion. Therefore, a short circuit may not occur between the electrode tab stacking portion and the surrounding electrode.

Further, in the battery cell according to another aspect of the present disclosure, the lead coupling portion may expose at least one of an upper surface, a first side surface, a second side surface, a lower surface, and a back surface of the electrode tab stacking portion. In accordance with another aspect of the present disclosure, a bonding area is increased as compared to a case in which a conventional electrode lead is bonded to an electrode tab on an upper surface of the electrode tab.

In this way, since the electrode leads surround at least a portion of the electrode tab stacking portion, the safety of the bonding between the electrode tabs and the electrode leads can be ensured, and the bonding area of the electrode tabs and the electrode leads can be increased, thereby improving bonding strength and reducing contact resistance. Since the form in which the electrode leads surround at least a portion of the electrode tab stack portion can be maintained during use, there is an effect of promoting current movement by maintaining improved bonding strength.

Drawings

The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure, and thus the present disclosure is not to be construed as limited to the accompanying drawings.

Fig. 1 is a plan view for describing a battery cell according to an embodiment of the present disclosure.

Fig. 2 is a perspective view for describing 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' of fig. 1.

Fig. 4 is a cross-sectional view taken along line B-B' of fig. 1.

Fig. 5 is a cross-sectional view taken along line C-C' in fig. 1.

Fig. 6 to 8 are perspective views for describing an example of a manufacturing method of the battery cell of fig. 1.

Fig. 9 and 10 are perspective views for describing another example of a manufacturing method of the battery cell of fig. 1.

Fig. 11 is a perspective view for describing another example of the first electrode lead included in the battery cell of fig. 1.

Fig. 12 is a plan view for describing a battery cell according to another embodiment of the present disclosure.

Fig. 13 is a perspective view for describing an example of a first electrode lead included in the battery cell of fig. 12.

Fig. 14 is a perspective view for describing a first electrode lead included in a battery cell according to still another embodiment of the present disclosure.

Fig. 15 is a perspective view for describing a first electrode lead included in a battery cell according to still another embodiment of the present disclosure.

Fig. 16 is a perspective view for describing a first electrode lead included in a battery cell according to still another embodiment of the present disclosure.

Fig. 17 is a view for describing a battery module including battery cells according to an embodiment of the present disclosure.

Fig. 18 is a view for describing a battery pack including the battery module of fig. 17.

Detailed Description

The present disclosure will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings. The embodiments described herein are shown by way of example to aid in understanding the present disclosure, and it is to be understood that the present disclosure may be variously modified and implemented other than the embodiments described herein. Furthermore, the figures are not shown to actual scale, but rather the dimensions of some of the components may be exaggerated to aid in the understanding of the present disclosure.

Fig. 1 is a plan view for describing a battery cell according to an embodiment of the present disclosure. Fig. 2 is a perspective view for describing 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' of fig. 1. Fig. 4 is a cross-sectional view taken along line B-B' of fig. 1. Fig. 5 is a cross-sectional view taken along line C-C' in fig. 1.

First, referring to fig. 1, a battery cell 10 according to an embodiment of the present disclosure may include an electrode assembly 100, a first electrode lead 210, and a second electrode lead 220.

The electrode assembly 100 may include a negative electrode 110, a positive electrode 120, a separator, a negative electrode tab stack portion 112, and a positive electrode tab stack portion 122.

In one embodiment, the negative electrodes 110 and the positive electrodes 120 may be placed alternately with each other, as shown in fig. 3 and 4. For example, the positive electrode 120 may be disposed between the negative electrodes 110. In addition, a separator may be interposed between the positive electrode 120 and the negative electrode 110. Accordingly, the electrode assembly 100 may be a stacked electrode assembly or a stacked/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 sequentially stacked with a separator interposed therebetween, and the stacked/folded electrode assembly may have a structure in which a bi-or full-unit is wound, in which the positive electrodes and the negative electrodes of the predetermined units are stacked with the separator interposed therebetween.

In one embodiment, referring to fig. 3, a negative electrode tab 111 may protrude from the negative electrode 110 in a first direction D1 (e.g., a protruding direction). Further, 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.

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

In one embodiment, as shown in fig. 1, the negative electrode tab stacking portion 112 and the positive electrode tab stacking portion 122 may be formed in parallel with each other on one side of the electrode assembly 100. Further, the negative electrode tab stacking portion 112 and the positive electrode tab stacking portion 122 may be formed to be spaced apart from each other. Accordingly, the first electrode lead 210 and the second electrode lead 220 may be disposed to be spaced apart from each other.

In one embodiment, the negative electrode 110 and the negative electrode tab 111 may be made of an alkali metal (e.g., lithium metal). For example, the electrode assembly 100 may be an electrode assembly for realizing a lithium sulfur battery, and a positive electrode active material including a sulfur compound may be applied to the positive electrode 120.

The first electrode lead 210 may be electrically connected to the electrode assembly 100 through the negative electrode tab stack portion 112. For example, the first electrode lead 210 may be bonded to the negative electrode tab stack portion 112. The first electrode lead 210 may be bonded to the negative electrode tab stack portion 112 by a known bonding method. For example, the first electrode lead 210 may be bonded to the negative electrode tab stack portion 112 by a pressure bonding method, an ultrasonic bonding method, a resistance bonding method, a laser bonding method, or the like. Accordingly, the first electrode lead 210 may contact the negative electrode tab stack portion 112 and guide 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.

The second electrode lead 220 may be electrically connected to the electrode assembly 100 through the positive electrode tab stacking portion 122. For example, the second electrode lead 220 may be coupled to the positive electrode tab stacking portion 122. In this way, the second electrode lead 220 may be a positive electrode lead.

In one embodiment, the first electrode lead 210 may have a rigidity 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 soft nature of the lithium metal may be supplemented to compensate for the characteristics of the negative electrode tab 111, which may be made of lithium metal.

The battery cell 10 according to the embodiment of the present disclosure includes a particularly modified first electrode lead 210. The first electrode lead 210 will be described in more detail with reference to fig. 2 to 5.

Referring to fig. 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 stacking portion 112 so as to be in contact with the negative electrode tab stacking portion 112. The first lead coupling portion 211 may protrude 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 guide the negative electrode 110 to the outside of the battery cell 10.

In one embodiment, the first lead coupling portion 211 may include an upper contact portion UC, a first side contact portion SC1, and a second side contact portion SC2.

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

For example, the first side surface SSF1 may be connected to the upper surface USF, and the second side surface SSF2 may be connected to the upper surface USF and opposite to the first side surface SSF 1. Accordingly, the first lead coupling portion 211 may contact the negative electrode tab stacking portion 112 while continuously surrounding the upper surface USF, the first side surface SSF1, and the second side surface SSF2.

In one embodiment, the first lead coupling portion 211 may be bent at a right angle at a corner portion where one surface of the negative electrode tab stack portion 112 is connected to the other surface thereof to surround at least a portion of the negative electrode tab stack portion 112. For example, the first lead coupling portion 211 may be bent at a right angle at a corner portion where the upper surface USF and the first side surface SSF1 of the negative electrode tab stack portion 112 are connected (e.g., a portion where the upper contact portion UC and the first side contact portion SC1 are connected). In addition, the first lead coupling portion 211 may be bent at a right angle at a corner portion where the upper surface USF and the second side surface SSF2 of the negative electrode tab stack portion 112 are connected (for example, a portion where the upper contact portion UC and the second side contact portion SC2 are connected).

In one embodiment, the first lead coupling portion 211 may have a first width W1 in a direction (e.g., the second direction D2) perpendicular to the protruding direction of the negative electrode tab 111, and the negative electrode tab stacking portion 112 may have a second width W2 in a direction (e.g., the 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, and thus, the first lead coupling portion 211 may sufficiently surround the negative electrode tab stacking portion 112 (W1 > W2).

Further, the width of the first extension portion 212 may be the same as the width of the first lead coupling portion 211, and may be greater than the width of the negative electrode tab stacking portion 112.

In one embodiment, the first lead coupling portion 211 may have a first height H1 in a 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, and thus, the first lead coupling portion 211 may sufficiently surround the negative electrode tab stacking portion 112.

Further, the first lead coupling portion 211 may expose the lower surface LSF and the back surface BSF of the negative electrode tab stacking portion 112. For example, the lower surface LSF is opposite to the upper surface USF, and may be connected to the first side surface SSF1 and the second side surface SSF2. The back surface BSF may be opposite to the protruding direction (e.g., the first direction D1) of the negative electrode tab 111.

The first extension portion 212 may extend from the first lead coupling portion 211. The first extension 212 may guide 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 the top of the first wire coupling portion 211. For example, the first extension portion 212 may be integrally formed with the first lead coupling portion 211. However, the present disclosure is not limited thereto, and the first extension portion 212 may extend from the middle or bottom of the first wire coupling portion 211.

The battery cell 10 may include: a negative electrode tab stacking portion 112 in which the negative electrode tabs 111 are aligned and stacked in the negative electrode tab stacking portion 112; and a first electrode lead 210 connected to the negative electrode tab stack portion 112. The first electrode lead 210 may surround at least a portion of the negative electrode tab stack portion 112, and for this purpose, the first electrode lead 21 may include an upper contact portion UC, a first side contact portion SC1, and a second side contact portion SC2. Since the first electrode lead 210 having a relatively large rigidity is formed to surround the negative electrode tab stack portion 112 having a relatively small rigidity, the first electrode lead 210 can prevent damage to the negative electrode tab stack portion 112 during bonding of the first electrode lead 210 and the negative electrode tab stack portion 112.

In addition, the first electrode lead 210 may expose the lower surface LSF and the back surface BSF of the negative electrode tab stack portion 112, and the lower surface LSF and the back surface BSF of the negative electrode tab stack portion 112 may not face the positive electrode tab stack portion 122. In the process of bonding the first electrode lead 210 and the negative electrode tab stack portion 112, the contact portions of the first lead coupling portion 211 and the negative electrode tab stack portion 112 are compressed so that the negative electrode tab stack portion 112 may be unfolded while being restrained by the first lead coupling portion 211. In other words, the negative electrode tab stack portion 112 may be pushed toward the exposed lower surface LSF and the back surface BSF, but not toward the upper surface USF, the first side surface SSF1, and the second side surface SSF2 covered by the first wire bonding portion 211. Therefore, a short circuit is unlikely to occur between the negative electrode tab stack portion 112 and the surrounding electrode (e.g., the positive electrode tab stack portion 122).

Referring to fig. 6, the preliminary first electrode lead P210 may include a preliminary first lead coupling portion P211 and a first extension portion 212. The preliminary first lead coupling portion P211 may be a spare member for forming the above-described first lead coupling portion 211, and may be flat 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 preliminary first lead coupling portion P211 in the plane. In this case, the width PW1 of the preliminary first wire coupling portion P211 may be greater than the width PW2 of the first extension portion 212.

Referring to fig. 7, the preliminary first electrode lead P210 and the negative electrode tab stacking portion 112 may be close to each other, and a portion of the preliminary first lead coupling portion P211 may contact the negative electrode tab stacking portion 112. For example, the portion of the preliminary first lead coupling portion P211 may contact the negative electrode tab located at the uppermost one of the negative electrode tabs 111 aligned on the negative electrode tab stacking portion 112.

Referring to fig. 8, the preliminary first lead coupling portion P211 may be bent to correspond to the shape of the negative electrode tab stacking portion 112. For example, the preliminary first lead coupling portion P211 may be bent and bonded to the negative electrode tab stack portion 112 by any one of the bonding methods described above. Accordingly, the first lead coupling portion 211 may be formed to surround at least a portion of the negative electrode tab stacking portion 112.

According to the manufacturing method described above with reference to fig. 6 to 8, the flat preliminary first lead coupling portion P211 may be brought into contact with the negative electrode tab stack portion 112 and then bent to correspond to the shape of the negative electrode tab stack portion 112, thereby forming the first lead coupling portion 211. Accordingly, the contact area between the first lead coupling portion 211 and the negative electrode tab stacking portion 112 may be increased, so that the resistance between the first lead coupling portion 211 and the negative electrode tab stacking portion 112 may be reduced. Further, the negative electrode tab 111 may be pushed to the lower surface LSF and/or the back surface BSF of the negative electrode tab stack portion 112 that does not face the surrounding electrode, so that a short circuit does not occur between the negative electrode tab stack portion 112 and the surrounding electrode (e.g., the positive electrode tab stack portion 122).

Referring to fig. 9, the first electrode lead 210 may include a first lead coupling portion 211 and a first extension portion 212. The first wire coupling portion 211 and the first extension portion 212 may be the first wire coupling portion 211 and the first extension portion 212 described above with reference to fig. 2. In other words, the first electrode lead 210 may be formed in advance to surround at least a portion of the negative electrode tab stack portion 112 to correspond to the shape of the negative electrode tab stack 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.

Referring to fig. 10, the first electrode lead 210 and the negative electrode tab stacking portion 112 are brought close to each other and pressed so that the upper contact portion UC, the first side contact portion SC1, and the second side contact portion SC2 of the first lead coupling portion 211 may be in contact with the negative electrode tab stacking portion 112.

According to the manufacturing method described above with reference to fig. 9 and 10, the first electrode lead 210 may be preformed corresponding to the shape of the negative electrode tab stack portion 112. Accordingly, the productivity of the bonding process of the first electrode lead 210 and the negative electrode tab stacking portion 112 can be improved, and the pushing phenomenon of the negative electrode tab 111 can be relatively reduced.

Referring to fig. 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 an upper contact portion UC', a first side contact portion SC1', and a second side contact portion SC2'. 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 a corner portion to be described later.

In one embodiment, the first lead coupling portion 211' may be bent into a curved surface at a corner portion where one surface of the negative electrode tab stack portion 112 is connected to the other surface thereof to cover at least a portion of the negative electrode tab stack portion 112. For example, the first lead coupling portion 211' may be bent into a curved surface at a corner portion where the upper surface USF and the first side surface SSF1 of the negative electrode tab stack portion 112 are connected (e.g., a portion where the upper contact portion UC ' and the first side contact portion SC1' are connected). Further, the first lead coupling portion 211' may be bent into a curved surface at a corner portion where the upper surface USF and the second side surface SSF2 of the negative electrode tab stack portion 112 are connected (e.g., a portion where the upper contact portion UC ' and the second side contact portion SC2' are connected). If bent into a curved surface at a corner portion where one surface of the negative electrode tab stack portion 112 is connected to the other surface thereof, stress concentration at the bent portion can be prevented as compared with the case of bending at right angles, and the risk of breakage or damage due to physical impact or fatigue accumulation during continuous use or handling can be reduced.

The shape of the first lead coupling portion 211 '(such as a shape in which the first lead coupling portion 211' is bent at an acute angle and/or at an obtuse angle) is not limited to the above-described case.

Fig. 12 is a plan view for describing a battery cell according to another embodiment of the present disclosure, and fig. 13 is a perspective view for describing an example of a first electrode lead included in the battery cell of fig. 12.

Referring to fig. 12, a battery cell 10' according to another embodiment of the present disclosure may include an electrode assembly 100, a first electrode lead 1210, and a second electrode lead 220. The battery cell 10' may be substantially the same as the battery cell 10 described with reference to fig. 1, except for the first electrode lead 1210.

Referring to fig. 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 surround at least a portion of the negative electrode tab stacking portion 112 so as to be in contact with the negative electrode tab stacking portion 112. The first lead coupling portion 1211 may have a shape protruding 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 guide the negative electrode 110 to the outside of the battery cell 10'.

In one embodiment, the first lead coupling portion 1211 may include an upper contact portion UC, a first side contact portion SC1, and a lower contact portion LC.

The upper contact portion UC may contact the upper surface USF of the negative electrode tab stack portion 112. The first side contact portion SC1 may contact the first side surface SSF1 of the negative electrode tab stack portion 112. The lower contact portion LC may contact the lower surface LSF of the negative electrode tab stack portion 112.

For example, the first side surface SSF1 may be connected to the upper surface USF, and the lower surface LSF may be connected to the first side surface SSF1 and opposite to the upper surface USF. Accordingly, the first lead coupling portion 1211 may contact the negative electrode tab stack portion 112 while continuously surrounding the upper surface USF, the first side surface SSF1, and the lower surface LSF.

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 stack portion 112. In this example, the second side surface SSF2 and the back surface BSF of the negative electrode tab stack portion 112 exposed by the first lead coupling portion 1211 may not face the positive electrode tab stack portion 122.

The battery cell 10' may include: a negative electrode tab stacking portion 112 in which the negative electrode tabs 111 are aligned and stacked; and a first electrode lead 1210 connected to the negative electrode tab stack portion 112. The first electrode lead 1210 may surround at least a portion of the negative electrode tab stack portion 112, and for this purpose, the first electrode lead 1210 may include an upper contact portion UC, a first side contact portion SC1, and a lower contact portion LC. Since the first electrode lead 1210 having a relatively large rigidity is formed to surround the negative electrode tab stack portion 112 having a relatively small rigidity, the first electrode lead 1210 may prevent damage to the negative electrode tab stack portion 112 during bonding of the first electrode lead 1210 and the negative electrode tab stack portion 112.

In addition, the first electrode lead 1210 may expose the second side surface SSF2 and the back surface BSF of the negative electrode tab stack portion 112, and the second side surface SSF2 and the back surface BSF of the negative electrode tab stack portion 112 may not face the positive electrode tab stack portion 122. In the process of bonding the first electrode lead 1210 and the negative electrode tab stacking portion 112, the contact portions of the first lead coupling portion 1211 and the negative electrode tab stacking portion 112 are compressed so that the negative electrode tab stacking portion 112 may be unfolded while being restrained by the first lead coupling portion 1211. In other words, the negative electrode tab stack portion 112 may be pushed toward the exposed second surface SSF2 and the back surface BSF, but not toward the upper surface USF, the first side surface SSF1, and the lower surface LSF covered by the first lead coupling portion 1211. Therefore, a short circuit is unlikely to occur between the negative electrode tab stack portion 112 and the surrounding electrode (e.g., the positive electrode tab stack portion 122).

Referring to fig. 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 surround at least a portion of the negative electrode tab stacking portion 112 so as to be in contact with the negative electrode tab stacking portion 112. The first lead coupling portion 311 may have a shape protruding 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 guide the negative electrode 110 to the outside of the battery cell.

In one embodiment, the first wire coupling portion 311 may include an upper contact portion UC, a back contact portion BC, a first lower contact portion LC1, and a second lower contact portion LC2.

The upper contact portion UC may contact the upper 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 lower contact portion LC1 may contact the lower surface LSF of the negative electrode tab stack portion 112. The second lower contact portion LC2 may integrally contact the first lower contact portion LC1 and may connect the first lower contact portion LC1 and the first extension portion 312. In other words, the first lead coupling portion 311 may be bent at 180 ° at the lower surface LSF. Therefore, the rigidity of the first wire coupling portion 311 can be improved.

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 stack portion 112.

In this way, the first lead coupling portion 311 is in contact with the upper surface USF, the back surface BSF, and the lower surface LSF of the negative electrode tab stack portion 112, and thus the contact area can be increased compared to a conventional bonding area, thereby reducing the resistance and maintaining the enhanced bonding strength. Since the first lead coupling portion 311 contacts the upper surface USF, the back surface BSF, and the lower surface LSF of the negative electrode tab stacking portion 112, it is possible to prevent damage of the negative electrode tab stacking portion 112 by surrounding at least three surfaces of the negative electrode tab stacking portion 112 during welding, thereby ensuring the safety of the negative electrode tab.

Referring to fig. 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 surround at least a portion of the negative electrode tab stack portion 112 so as to be in contact with the negative electrode tab stack portion 112. The first lead coupling portion 411 may have a shape protruding 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 guide the negative electrode 110 to the outside of the battery cell.

In one embodiment, the first lead coupling portion 411 may include an upper contact portion UC, a first side contact portion SC1, a second side contact portion SC2, and a lower contact portion LC.

The upper contact portion UC may contact the upper surface USF of the negative electrode tab stack portion 112. The first side contact portion SC1 may contact the first side surface SSF1 of the negative electrode tab stack portion 112. The second side contact portion SC2 may contact the second side surface SSF2 of the negative electrode tab stack portion 112. The lower contact portion LC may contact the lower surface LSF of the negative electrode tab stack portion 112.

In addition, the first lead coupling portion 411 may expose the back surface BSF of the negative electrode tab stacking portion 112. In this case, the back surface BSF of the negative electrode tab stack portion 112 exposed by the first lead coupling portion 411 may not face the positive electrode tab stack portion 122, and thus, a short circuit may not occur between the negative electrode tab stack portion 112 and the surrounding electrode (e.g., the positive electrode tab stack portion 122).

That is, the first lead coupling portion 411 contacts the upper surface USF, the first side surface SSF1, the second side surface SSF2, and the lower surface LSF of the negative electrode tab stack portion 112, which may be referred to as a doughnut shape, and may increase a contact area compared to a conventional bonding area, thereby reducing resistance and maintaining enhanced bonding strength. The negative electrode tab stacking portion 112 may be placed within the first lead coupling portion 411 in the shape of an annular ring to be welded under compression. The space formed by the upper contact portion UC, the first side contact portion SC1, the second side contact portion SC2, and the lower contact portion LC of the first lead coupling portion 411 is larger than the volume of the negative electrode tab stack portion 112, whereby there is enough space to easily assemble when the negative electrode tab stack portion 112 is placed inside the first lead coupling portion 411. By reducing the space formed by the upper contact portion UC, the first side contact portion SC1, the second side contact portion SC2, and the lower contact portion LC of the first lead coupling portion 411 when welding is performed under pressing, contact and coupling between the first lead coupling portion 411 and the negative electrode tab stack portion 112 can be reinforced.

Since the first lead coupling portion 411 exposes the back surface BSF of the negative electrode tab stacking portion 112 and surrounds the four surfaces of the negative electrode tab stacking portion 112, damage of the negative electrode tab stacking portion 112 during welding can be prevented, thereby ensuring safety of the negative electrode tab. In addition, even if the negative electrode tab stack portion 112 is pressed during welding, the first lead coupling portion prevents contact with the surrounding electrode, thereby preventing a short circuit from occurring with the surrounding electrode.

Referring to fig. 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 surround at least a portion of the negative electrode tab stacking portion 112 so as to be in contact with the negative electrode tab stacking portion 112. The first lead coupling portion 511 may have a shape protruding 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 guide the negative electrode 110 to the outside of the battery cell.

In one embodiment, the first wire coupling portion 511 may include an upper contact portion UC, a lower contact portion LC, and a central contact portion CC.

The upper contact portion UC may contact the upper surface USF of the negative electrode tab stack portion 112. The lower contact portion LC may contact the lower surface LSF of the negative electrode tab stack portion 112. In the negative electrode tab stacking portion 112, a central surface CSF that is located between and parallel to the upper surface USF and the lower surface LSF may also be defined, and the central contact portion CC may contact the central surface CSF. In other words, the central contact portion CC may be inserted into any one boundary of the stacked negative electrode tabs 111. Accordingly, the negative electrode tab stack portion 112 and the first lead coupling portion 511 can be electrically connected more smoothly.

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 stack portion 112.

The central contact portion CC may be interposed between the stacked negative electrode tabs 111, and the upper and lower contact portions UC and LC may be wrapped around the outermost portions of the negative electrode tab stack portion 112, and then may be subjected to bonding welding. The contact area can be increased compared to the conventional bonding area, thereby reducing the resistance and maintaining the enhanced bonding strength. Since damage to the negative electrode tab stacking portion 112 during welding can be prevented, safety of the negative electrode tab can be ensured. In addition, when the number of stacked negative electrode tabs 111 is large, the center contact portion CC included in the first lead coupling portion 511 of the present embodiment may further prevent the deintercalation.

Fig. 17 is a view for describing a battery module including battery cells according to an embodiment of the present disclosure, and fig. 18 is a view for describing a battery pack including the battery module of fig. 17.

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

Although small-sized mobile devices use one or two to four battery cells per device, medium/large-sized devices such as vehicles require high output and large capacity. Accordingly, a middle/large-sized battery module including a cell stack electrically connecting a plurality of battery cells is used. A battery module BM manufactured by electrically connecting the battery cells 10 may be used as such a middle/large-sized battery module. Each of the battery cells 10 is connected to each other to secure necessary power according to the purpose of requiring the power of the battery module BM.

Referring to fig. 18, the battery pack BP may include at least one battery module BM described with reference to fig. 17 and a battery pack case PC encapsulating the battery module BM.

The battery pack BP according to the present disclosure may further include various devices for controlling the charge/discharge of the battery module BM, such as a Battery Management System (BMs), a current sensor, a fuse, and the like. The BMS estimates the states of the cells in the battery pack BP and manages the battery pack BP using the estimated state information. For example, the BMS estimates and manages state information of the battery pack BP, such as a state of charge (SOC), a state of health (SOH), a maximum input/output power margin, and a battery pack BP output voltage. Further, using such state information, the charge or discharge of the battery pack BP can be controlled, and furthermore, even the replacement time of the battery pack BP can be estimated.

The battery modules BM may have a substantially rectangular parallelepiped shape, are arranged in the battery pack case PC in an orderly manner, and each battery module BM is connected to each other to secure necessary power according to the purpose of requiring the power of the battery pack BP.

While the present disclosure has been described above with respect to a limited number of embodiments and figures, the present disclosure is not so limited, and it will be apparent to those skilled in the art that various modifications and changes can be made thereto within the technical aspects of the present disclosure and the equivalent scope of the appended claims.

[ Description of reference numerals ]

10. 10': Cell 100: electrode assembly

110 Negative electrode 120 positive electrode

111 Negative electrode tab 112 negative electrode tab stacking portion

210. 1210 First electrode lead 220 second electrode lead

211. 1211 First lead coupling portions 212, 1212 first extension portion

Claims

1. A battery cell comprising:

An electrode assembly including an electrode and an electrode tab stacking portion in which electrode tabs protruding from the electrode are aligned and stacked in a vertical direction; and

An electrode lead including a lead coupling portion surrounding at least a portion of the electrode tab stack portion,

Wherein the lead coupling portion continuously surrounds and contacts any one of an upper surface of the electrode tab stacking portion, a first side surface connected to the upper surface, a second side surface opposite to the first side surface, and a lower surface opposite to the upper surface, and the other of the second side surface and the lower surface opposite to the upper surface is exposed.

2. The battery cell according to claim 1,

Wherein the electrode tab stacking portion has a back surface defined opposite to a protruding direction of the electrode tab,

Wherein the lead coupling portion exposes the back surface of the electrode tab stacking portion.

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 greater 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 battery cell according to claim 1,

Wherein the electrode lead further includes an extension portion extending from the lead coupling portion to guide the electrode to the outside of the battery cell,

Wherein a width of the lead coupling portion in a direction perpendicular to a protruding direction of the electrode tab is greater than a width of the extension portion in a 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 at a corner portion where one surface of the electrode tab stacking portion is connected to the other surface thereof to surround at least a portion of the electrode tab stacking portion.

7. The battery cell according to claim 5,

Wherein the lead coupling portion is bent into a curved shape at a corner portion where one surface of the electrode tab stacking portion is connected to the other surface thereof to surround at least a portion of the electrode tab stacking portion.

8. The battery cell according to claim 5,

Wherein the lead coupling portion has a shape protruding from a side surface of the extension portion.

9. The battery cell according to claim 1,

Wherein the lead coupling portion has a rigidity greater than that of the electrode tab.

10. The battery cell according to claim 9,

Wherein each of the electrode tabs is made of lithium metal.

11. The battery cell according to claim 9,

Wherein the lead coupling portion is made of a metal different from lithium metal.

12. The battery cell according to claim 1,

Wherein the electrode is a negative electrode, the electrode tab is a negative electrode tab and made of lithium metal, and the electrode tab stack portion is a negative electrode tab stack portion,

Wherein the electrode assembly further includes a positive electrode, a separator is interposed between each of the negative electrodes and a positive electrode tab stacking portion in which positive electrode tabs protruding from the positive electrode are aligned and stacked in the vertical direction, and the positive electrode tabs are made of a metal other than lithium metal,

Wherein the negative electrode tab stacking portion and the positive electrode tab stacking portion are formed parallel to each other on one side of the electrode assembly, and the second side surface or the lower surface of the negative electrode tab stacking portion exposed through the lead coupling portion does not face the positive electrode tab stacking portion.

13. The battery cell according to claim 12,

Wherein the contact portions of the lead coupling portion and the negative electrode tab stacking portion are compressed such that the negative electrode tab stacking portion expands while being restrained by the lead coupling portion.

14. A battery cell comprising:

Wherein the lead coupling portion exposes at least one of an upper surface of the electrode tab stacking portion, a first side surface connected to the upper surface, a second side surface opposite to the first side surface, a lower surface opposite to the upper surface, and a back surface connected to the lower surface and opposite to a protruding direction of the electrode tab.

15. The battery cell according to claim 14,

Wherein the wire coupling portion contacts the upper surface, the back surface, and the lower surface and exposes the first side surface and the second side surface.

16. The battery cell according to claim 14,

Wherein the wire coupling portion contacts the upper surface, the first side surface, the second side surface, and the lower surface, and exposes the back surface.

17. The battery cell according to claim 14,

Wherein the electrode tab stacking portion has a central surface, the central surface being further defined as being located between and parallel to the upper and lower surfaces,

Wherein the wire coupling portion contacts the upper surface, the central surface, and the lower surface and exposes the first side surface, the second side surface, and the back surface.

18. A battery module, comprising: at least one battery cell according to any one of claims 1 to 17; and a module case accommodating the at least one battery cell.

19. A battery pack, comprising: at least one battery module according to claim 18; and a battery pack case enclosing the at least one battery module.