Secondary battery

Abstract

A secondary battery includes an electrode assembly including a first electrode tab on one side and a second electrode tab on the other side, a case having at least one open side and accommodating the electrode assembly, a first cover plate coupled to one open side of the case, a first electrode terminal electrically connected to the first electrode tab and exposed outside the first cover plate, a first sub plate electrically connecting the first electrode tab and the first electrode terminal, and a first insulator between the first cover plate and the electrode assembly, wherein the first sub plate includes a first plate portion coupled to the first electrode tab, a first tab portion having one end coupled to the first plate portion and the other end coupled to the first electrode terminal, and a first coating layer on at least a portion of a surface of the first tab portion.

Description

Technical Field

[0001] This disclosure relates to a secondary battery. Background Technology

[0002] Unlike primary batteries, which are not designed for (re)charging, secondary (or rechargeable) batteries are designed to discharge and be recharged. Low-capacity secondary batteries are used in portable small electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for driving motors in hybrid and electric vehicles, as well as for storing electricity (e.g., household and / or utility-scale power storage). A secondary battery typically includes an electrode assembly containing positive and negative electrodes, a housing of the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] The information disclosed in this background section is intended to enhance the understanding of the background of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0004] An embodiment includes a secondary battery comprising: an electrode assembly including a first electrode tab on one side and a second electrode tab on the other side; a housing having at least one open side, the housing accommodating the electrode assembly; a first cover plate coupled to one open side of the housing; a first electrode terminal electrically connected to the first electrode tab, the first electrode terminal being exposed outside the first cover plate; a first sub-plate electrically connected to the first electrode tab and the first electrode terminal; and a first insulator between the first cover plate and the electrode assembly, wherein the first sub-plate comprises: a first plate portion coupled to the first electrode tab; a first tab portion having one end coupled to the first plate portion and the other end coupled to the first electrode terminal; and a first coating layer on at least a portion of the surface of the first tab portion.

[0005] The first plate portion may include: a first welding portion welded to the first electrode tab; and a first protruding portion connected to the first welding portion, the first protruding portion protruding from the first welding portion toward the first cover plate.

[0006] The first weld portion may be provided as a plurality of first weld portions spaced apart from each other, with the first protrusion portion located therebetween.

[0007] The first connector portion can be soldered to the first protrusion at one end, and the first connector portion can be soldered to the first electrode terminal at the other end.

[0008] The first connector portion may include a first connection portion between one end of the first connector portion that is soldered to the first protrusion and the other end of the first connector portion that is soldered to the first electrode terminal.

[0009] When the first connector portion is in the unfolded state, the length of the first connector portion welded to one end of the first protrusion can be 10% to 30% of the total length of the first connector portion.

[0010] When the first connector portion is in the unfolded state, the length of the first connector portion welded to the other end of the first electrode terminal can be 10% to 30% of the total length of the first connector portion.

[0011] When the first connector portion is in the unfolded state, the length of the first connecting portion can be 40% to 80% of the total length of the first connector portion.

[0012] The first coating layer may surround at least a portion of the first connection portion of the first terminal block portion.

[0013] The first terminal piece may be bent at least once at the first connection portion on which the first coating layer is located.

[0014] The first coating layer can be an adhesive film.

[0015] The width of the adhesive film can correspond to the perimeter of the first connecting portion, which is twice the sum of the width and thickness of the first connecting portion.

[0016] The adhesive film may include an adhesive layer on the surface of the adhesive film facing the first terminal piece portion.

[0017] The first coating layer may contain at least one of a heat-resistant material and a chemical-resistant material.

[0018] The first coating layer may contain at least one of liquid crystal polymer, polyvinylidene fluoride, polyether ether ketone, and polyphenylene sulfide.

[0019] The first insulator may include: a first opening through which the first terminal portion of the first sub-board passes; and a plurality of first body portions spaced apart from each other, with the first opening located therebetween.

[0020] The first electrode terminal may include: a first current collector having a through hole on the surface of the first cover plate facing the electrode assembly; a first terminal plate having a through hole on the surface of the first cover plate opposite to the surface facing the electrode assembly; and a first rivet engaging the through hole of the first current collector and the through hole of the first terminal plate, the first rivet penetrating the first cover plate.

[0021] The secondary battery may further include: a second cover plate connected to another open side of the housing; a second electrode terminal electrically connected to a second electrode tab, the second electrode terminal being exposed outside the second cover plate; a second sub-plate electrically connected to the second electrode tab and the second electrode terminal; and a second insulator between the second cover plate and the electrode assembly.

[0022] The second sub-board may include: a second plate portion connected to the second electrode terminal; a second terminal portion having one end connected to the second plate portion and the other end connected to the second electrode terminal; and a second coating layer on at least a portion of the surface of the second terminal portion.

[0023] The second terminal block portion may include a second connection portion between one end of the second terminal block portion that is soldered to the second plate portion and the other end of the second terminal block portion that is soldered to the second electrode terminal, and the second coating layer surrounds at least a portion of the second connection portion.

[0024] These and other aspects and features of this disclosure will be apparent from or described in the following description of embodiments of this disclosure.

[0025] However, the aspects and features of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the detailed description below that other aspects and features not mentioned will be apparent. Attached Figure Description

[0026] The accompanying drawings illustrate embodiments of the present disclosure and, together with the detailed description thereof, further describe aspects and features of the disclosure. Therefore, this disclosure should not be construed as limited to the drawings.

[0027] Features will become apparent to those skilled in the art from the detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0028] Figure 1 A perspective view illustrating an example of a secondary battery according to an embodiment of the present disclosure;

[0029] Figure 2 An exploded perspective view illustrating an example of a secondary battery according to an embodiment of the present disclosure;

[0030] Figure 3 This is an example along Figure 1 A cross-sectional view of the secondary battery section intercepted by line A-A' in the diagram;

[0031] Figure 4 This is an example Figure 3 A magnified view of part B;

[0032] Figure 5 This is a side cross-sectional view illustrating an example of a secondary battery according to an embodiment of the present disclosure;

[0033] Figure 6 A perspective view illustrating an example of an electrode assembly according to an embodiment of the present disclosure;

[0034] Figure 7 An illustrative perspective view showing the state in which the first electrode terminal and the first sub-board are connected according to an embodiment of the present disclosure;

[0035] Figure 8 An exploded perspective view of a first sub-board according to an embodiment of the present disclosure is shown;

[0036] Figure 9 An illustrative perspective view showing an example of the connection between a first electrode terminal and a first sub-board according to an embodiment of the present disclosure;

[0037] Figure 10 An example perspective view showing a state in which a first insulator is connected according to an embodiment of the present disclosure;

[0038] Figure 11 An illustrative perspective view showing an example of the connection of a first insulator according to an embodiment of the present disclosure;

[0039] Figure 12 An illustrative perspective view showing an example of the connection between a first cover plate and a first electrode terminal according to an embodiment of the present disclosure; and

[0040] Figure 13 A perspective view illustrating an example of a first connector portion in an unfolded state according to an embodiment of the present disclosure. Detailed Implementation

[0041] Exemplary embodiments will now be described more fully below with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be comprehensive and complete, and will fully convey exemplary implementation methods to those skilled in the art.

[0042] In the drawings, the dimensions of layers and regions may be enlarged for clarity of illustration. It will also be understood that when a layer or element is referred to as "on" another layer or substrate, it may be directly on that other layer or substrate, or there may be intervening layers. Furthermore, it will be understood that when a layer is referred to as "below" another layer, it may be directly below, and there may be one or more intervening layers. Additionally, it will be understood that when a layer is referred to as "between two layers," it may be the only layer between those two layers, or there may be one or more intervening layers. Similar reference numerals always refer to similar elements.

[0043] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as limited to their general or dictionary meaning, but should be interpreted based on the principle that the inventor is capable of being his / her own lexicographer to appropriately define the concepts of the terms in a manner best suited to interpret his / her own invention, and are therefore interpreted as having meanings and concepts consistent with the technical spirit of the present disclosure.

[0044] The embodiments described in this specification and the configurations shown in the accompanying drawings are merely some embodiments of this disclosure and do not represent all the technical ideas, aspects, and features of this disclosure. Accordingly, it should be understood that various equivalents and modifications may exist to replace or modify the embodiments described herein at the time of filing this application.

[0045] It will be understood that when an element or layer is referred to as being "on" another element or layer, "connected to," or "linked to" another element or layer, it can be directly on, directly connected to, or directly linked to the other element or layer, or one or more intermediary elements or layers may be present. When an element or layer is referred to as being "directly on" another element or layer, "directly connected to," or "directly linked to" another element or layer, no intermediary element or layer is present. For example, when a first element is described as being "linked" or "connected" to a second element, the first element can be directly linked to or connected to the second element, or the first element can be indirectly linked to or connected to the second element via one or more intermediary elements.

[0046] In the figures, the dimensions of various elements, layers, etc., may be enlarged for clarity of illustration. The same reference numerals denote the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the related listed items. Furthermore, when describing embodiments of this disclosure, the use of "may" refers to "one or more embodiments of this disclosure." Expressions such as "at least one of..." and "any one of..." modify the entire list of elements when preceding / following it, and do not modify individual elements in that list. When phrases such as "at least one of A, B, and C," "at least one of A, B, or C," "at least one selected from the group of A, B, and C," or "at least one selected from A, B, and C" are used to refer to a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the term "use" may be considered synonymous with the term "utilize." As used herein, the terms “substantially,” “about,” and similar terms are used as approximate terms and not as terms of degree, and are intended to describe the inherent variations in measured or calculated values ​​that would be recognized by one of ordinary skill in the art.

[0047] It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or segment from another element, component, region, layer, or segment. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment.

[0048] For ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” are used herein to describe the relationship between one element or feature and another, as illustrated in the figure. It will be understood that spatial relative terms are intended to cover different orientations of the device in use or operation other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as “below” or “under” other elements or features would then be oriented as “above” or “above” other elements or features. Therefore, the term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptive terms used herein should be interpreted accordingly.

[0049] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure. As used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprising” and / or “including” as used in this specification specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0050] Furthermore, any numerical range disclosed and / or described herein is intended to include all subranges with the same numerical precision contained within the described range. For example, the range “1.0 to 10.0” is intended to include all subranges between 1.0 and 10.0 (and inclusive), i.e., having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit described herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit described herein is intended to include all higher numerical limits contained therein. Accordingly, the applicant reserves the right to amend this specification, including the claims, to explicitly describe any subranges contained within the range explicitly described herein.

[0051] Referring to two compared elements, features, etc., as “identical” can mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include cases where the deviation is considered low in the art (e.g., 5% or less). Additionally, when a parameter is said to be consistent in a given region, it can mean that it is consistent in terms of average value.

[0052] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0053] Placing any element "above (or below)" or "on (below)" another element can mean that the arbitrary element can be positioned to contact the upper (or lower) surface of the element, or that the other element can be positioned between the element and the arbitrary element positioned on (or below) the element.

[0054] Additionally, it will be understood that when a component is referred to as a “connection,” “link,” or “attachment” to another component, these components can be directly connected, linked, or joined to each other, or another component can be located between these components.

[0055] Throughout this specification, unless otherwise stated, when “A and / or B” is used, it means A, B, or A and B. That is, “and / or” includes any or all of the listed items. Unless otherwise stated, when “C~D” is used, it means C and below D.

[0056] Figure 1 This is a perspective view illustrating an example of a secondary battery according to an embodiment of the present disclosure, and Figure 2 This is an exploded perspective view illustrating an example of a secondary battery according to an embodiment of the present disclosure.

[0057] refer to Figure 1 and Figure 2 The secondary battery 100 may include an electrode assembly 300, a housing 110, a first cover plate 120, a first electrode terminal 130, a first sub-plate 140, and a first insulator 150. The secondary battery 100 may further include a second cover plate 220, a second electrode terminal 230, a second sub-plate 240, and a second insulator 250. The first cover plate 120, the first electrode terminal 130, the first sub-plate 140, and the first insulator 150 may be symmetrically arranged relative to the electrode assembly 300 with respect to the second cover plate 220, the second electrode terminal 230, the second sub-plate 240, and the second insulator 250. In the following description, for ease of description, the explanation will focus on the first cover plate 120, the first electrode terminal 130, the first sub-plate 140, and the first insulator 150.

[0058] The electrode assembly 300 may include a first electrode tab formed on one side thereon (e.g., a first electrode tab formed on one side of the electrode assembly 300) and a second electrode tab formed on the other side thereon (e.g., the other side of the electrode assembly 300). That is, the electrode assembly 300 may include a first electrode tab connected to a first electrode plate on one side and a second electrode tab connected to a second electrode plate on the other side. (Refer to the following...) Figure 6 Describe its details.

[0059] The electrode assembly 300 can be housed together with the electrolyte in the housing 110. For example, the electrolyte may include a lithium salt (such as lithium hexafluorophosphate (LiPF6) or lithium tetrafluoroborate (LiBF4)) dissolved in an organic solvent (such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), or dimethyl carbonate (DMC)). The electrolyte can be in a liquid or gel state. As another example, an inorganic solid electrolyte can replace the function of the electrolyte.

[0060] The housing 110 can form the overall appearance of the secondary battery 100 and can be made of a conductive metal such as aluminum, aluminum alloy, stainless steel, iron, or nickel-plated steel. In addition, the housing 110 can provide space to accommodate the electrode assembly 300.

[0061] According to one embodiment, the housing 110 may be a prismatic housing, and the secondary battery 100 may be a prismatic secondary battery. However, the secondary battery 100 may be any type of secondary battery, such as a prismatic, cylindrical, or pouch-shaped secondary battery.

[0062] The housing 110 may have at least one open side. For example, the housing 110 may be a hollow cuboid with an opening formed on at least one side. Through this opening, the electrode assembly 300 connected to the first sub-plate 140 and the second sub-plate 240 may be accommodated in the housing 110. Specifically, the housing 110 may include: a rectangular upper surface and a lower surface extending in the length (or longitudinal) direction (Z-axis direction) of the housing 110; and a long side surface connecting the upper and lower long edges of the upper and lower surfaces, the long side surface extending in the Z-axis direction of the housing 110. The upper surface, lower surface and long side surface of the housing 110 may be integrally formed.

[0063] The housing 110 may include a safety vent 112 formed on at least one surface. For example... Figure 1 and Figure 2 As shown, a safety vent 112 may be formed on the upper surface of the housing 110. The safety vent 112 may include a notch that is thinner than other areas of the safety vent 112, thereby opening under a predetermined pressure.

[0064] The first cover plate 120 may have a rectangular plate shape and may be connected to an open side of the housing 110. The housing 110 and the first cover plate 120 may be formed of a conductive material. The first cover plate 120 may include electrode terminal holes and an electrolyte injection opening 122 penetrating the outer and inner surfaces of the first cover plate 120. A first electrode terminal 130 may be connected to the first cover plate 120 through the electrode terminal holes. After the first cover plate 120 is connected to the opening of the housing 110, the electrolyte injection opening 122 may be formed to inject electrolyte into the interior of the housing 110. After electrolyte injection, the electrolyte injection opening 122 may be sealed with a sealing member.

[0065] The first electrode terminal 130 can be electrically connected to the first electrode tab and can be exposed outside the first cover plate 120. The first electrode terminal 130 can be formed of metal and can be electrically connected to the first sub-plate 140 by contacting and soldering it to the first sub-plate 140. According to one embodiment, the first electrode terminal 130 may include: a first current collector having a through hole and disposed on the surface of the first cover plate 120 facing the electrode assembly 300; a first terminal plate having a through hole and disposed on the surface of the first cover plate 120 opposite to the surface facing the electrode assembly 300; and a first rivet engaging the through hole of the first current collector and the through hole of the first terminal plate and penetrating the first cover plate 120. The first electrode terminal 130 can be formed of the same metal as the first sub-plate 140. The first electrode terminal 130 can be formed of any of copper, copper alloy, aluminum, and aluminum alloy, but variations are possible. Reference is made below. Figure 3 and Figure 4 Describe further details.

[0066] The first daughter plate 140 may be formed of metal and may electrically connect the first electrode tab and the first electrode terminal 130. According to one embodiment, the first daughter plate 140 may include: a first plate portion connected to the first electrode tab; a first tab portion having one end connected to the first plate portion and another end connected to the first electrode terminal 130 (e.g., opposite ends); and a first coating layer 146 disposed on at least a portion of the surface of the first tab portion. The first coating layer 146 may be arranged to surround at least a portion of the first connecting portion of the first tab portion. Reference is made below. Figures 7 to 13 To describe more details. The first sub-board 140 can be formed from any of copper, copper alloy, aluminum, and aluminum alloy, but this can vary.

[0067] A first insulator 150 may be located between the first cover plate 120 and the electrode assembly 300. The first insulator 150 may comprise an insulating material. Therefore, it can prevent one side of the electrode assembly 300 from making electrical contact with the first cover plate 120. According to one embodiment, the first insulator 150 may include: a first opening through which a first terminal piece portion of the first daughter plate 140 passes; and a plurality of first body portions correspondingly spaced apart from each other, with the first opening located between them. Reference is made below. Figure 10 Describe further details.

[0068] The second cover plate 220 may have a rectangular plate shape and may be connected to another open side of the housing 110. The second cover plate 220 may include an electrode terminal hole passing through the outer and inner surfaces of the second cover plate 220. The second electrode terminal 230 may be connected to the second cover plate 220 through the electrode terminal hole.

[0069] The second electrode terminal 230 can be electrically connected to the second electrode tab and can be exposed outside the second cover plate 220. The second electrode terminal 230 can be formed of metal and can be electrically connected to the second sub-plate 240 by contacting and soldering it to the second sub-plate 240. According to one embodiment, the second electrode terminal 230 may include: a second current collector 236 having a through hole disposed on the surface of the second cover plate 220 facing the electrode assembly 300; a second terminal plate 232 having a through hole and disposed on the surface of the second cover plate 220 opposite to the surface facing the electrode assembly 300; and a second rivet 234 engaging the through hole of the second current collector 236 and the through hole of the second terminal plate 232 and passing through the second cover plate 220. The second electrode terminal 230 can be formed of the same metal as the second sub-plate 240.

[0070] The second electrode terminal 230 may have the same shape and structure as the first electrode terminal 130, except that the second electrode terminal 230 may be connected to the electrode assembly 300 via the second daughter plate 240 in a manner symmetrical with respect to the electrode assembly 300 as the first electrode terminal 130 is with respect to the electrode assembly 300. The second electrode terminal 230 may be formed of any of copper, copper alloy, aluminum, and aluminum alloy, but this can vary.

[0071] The second sub-board 240 may be formed of metal and may electrically connect the second electrode tab and the second electrode terminal 230. According to one embodiment, the second sub-board 240 may include: a second plate portion connected to the second electrode tab; a second tab portion having one end connected to the second plate portion and the other end connected to the second electrode terminal 230; and a second coating layer 246 disposed on at least a portion of the surface of the second tab portion. Here, the second tab portion may include a second connection portion located between the end of the second tab portion soldered to the second plate portion and the other end of the second tab portion soldered to the second electrode terminal 230. The second coating layer 246 may be arranged to surround at least a portion of the second connection portion. The second sub-board 240 may be connected to the electrode assembly 300 and the second electrode terminal 230 in a shape symmetrical with respect to the electrode assembly 300, as the first sub-board 140 is. The second sub-board 240 may be formed of any of copper, copper alloy, aluminum, and aluminum alloy, but this can vary.

[0072] A second insulator 250 may be located between the second cover plate 220 and the electrode assembly 300. The second insulator 250 may comprise an insulating material. Therefore, it can prevent one side of the electrode assembly 300 from making electrical contact with the second cover plate 220. According to one embodiment, the second insulator 250 may include a second opening through which a second terminal piece portion of the second sub-plate 240 passes; and a plurality of second body portions correspondingly formed to be spaced apart from each other, with the second opening located therebetween.

[0073] The secondary battery 100 can be, for example, a lithium-ion battery cell or a sodium-ion battery cell. However, the secondary battery 100 can encompass all batteries that can repeatedly provide power through charging and discharging. In one embodiment, if the secondary battery 100 is a lithium-ion secondary battery, it can exhibit excellent lifespan characteristics and high rate capability, thus making it suitable for use in electric vehicles (EVs). It can also be used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs). Lithium-ion secondary batteries can be used in applications requiring the storage of large amounts of electricity. For example, it can be used in electric bicycles or power tools.

[0074] Figure 3 It is along Figure 1 A cross-sectional view of the secondary battery section intercepted by line A-A', and Figure 4 This is an example Figure 3 A magnified view of part B. For ease of description, the explanation will focus primarily on the first cover plate 120, the first electrode terminal 130, the first daughter plate 140, and the first insulator 150, but the second cover plate 220, the second electrode terminal 230, the second daughter plate 240, and the second insulator 250 can be described similarly.

[0075] refer to Figure 3 and Figure 4 The secondary battery 100 may include a first cover plate 120, a first electrode terminal 130, and a first insulator 150. According to one embodiment, the first electrode terminal 130 may include: a first current collector 136 having a through hole and disposed on the surface of the first cover plate 120 facing the electrode assembly 300; a first terminal plate 132 having a through hole and disposed on the surface of the first cover plate 120 opposite to the surface facing the electrode assembly 300; and a first rivet 134 engaging the through hole of the first current collector 136 and the through hole of the first terminal plate 132 and penetrating the first cover plate 120.

[0076] An inner insulating member may be located between the inner surface of the first cover plate 120 and the first rivet 134. The inner insulating member may be in close contact with the inner surface of the first cover plate 120. The inner insulating member may contain insulating material and may insulate the first cover plate 120 from the first rivet 134. Furthermore, an outer insulating member may be located between the outer surface of the first cover plate 120 and the first terminal plate 132. The outer insulating member may be in close contact with the first cover plate 120, and may also be in close contact with the first rivet 134 and the first terminal plate 132. The outer insulating member may contain insulating material and may insulate the first cover plate 120 from the first terminal plate 132. In other words, the first cover plate 120 can be electrically isolated from the first electrode terminal 130 by the inner and outer insulating members.

[0077] A first insulator 150 may be located between the first cover plate 120 and the electrode assembly 300. The first insulator 150 may contain an insulating material and prevent one side of the electrode assembly 300 from making electrical contact with the first cover plate 120. The first insulator 150 may include a through-hole 152. Therefore, if electrolyte is injected through the electrolyte injection opening 122 of the first cover plate 120, the electrolyte can easily move into the interior of the electrode assembly 300 through the through-hole 152.

[0078] Figure 5 This is a side cross-sectional view illustrating an example of a secondary battery according to an embodiment of the present disclosure. (See reference...) Figure 3 and Figure 4 Redundant descriptions of the explained components have been omitted.

[0079] refer to Figure 5 The first sub-board 140 may include: a first board portion 142 connected to a first electrode terminal piece; a first terminal piece portion 144 having one end 144a connected to the first board portion 142 and another end 144c (e.g., other ends) connected to the first electrode terminal 130; and a first coating layer 146 disposed on at least a portion of the surface of the first terminal piece portion 144.

[0080] According to one embodiment, the first connector portion 144 may include a first connection portion 144b located between one end 144a of the first connector portion 144 that is soldered to the first plate portion 142 and the other end 144c of the first connector portion 144 that is soldered to the first electrode terminal 130.

[0081] According to one embodiment, a first coating layer 146 may be formed to surround at least a portion of the first connecting portion 144b of the first connector portion 144. For example, the first coating layer 146 may be formed to surround the entire first connecting portion 144b of the first connector portion 144 (i.e., the first coating layer 146 may be on both sides of the first connector portion 144). Accordingly, the first coating layer 146 may reinforce the first connecting portion 144b of the first connector portion 144 and prevent damage to the first connector portion 144 that may occur due to external impact. Specifically, the first coating layer 146 may prevent the first connector portion 144 from detaching due to external forces acting in a direction perpendicular to the protrusion direction (Z-axis direction) of the first connector portion 144 (X-axis direction and / or Y-axis direction).

[0082] According to one embodiment, the first connector portion 144 may be bent at least once at the first connecting portion 144b where the first coating layer 146 is disposed. For example... Figure 5As shown, the first connecting portion 144b to which the first coating layer 146 is applied can be bent twice in a zigzag pattern. The bent portions of the first connecting portion 144b to which the first coating layer 146 is applied can be formed near one end 144a of the first connector portion 144 and near the other end 144c of the first connector portion 144.

[0083] Figure 6 An example of an electrode assembly according to an embodiment of the present disclosure is shown.

[0084] refer to Figure 6 The electrode assembly 300 may include a first electrode plate 310, a second electrode plate 320, and a diaphragm 330 between the first electrode plate 310 and the second electrode plate 320. The first electrode plate 310, the second electrode plate 320, and the diaphragm 330 may be formed in the shape of a thin plate or a film. The electrode assembly 300 may have the following structure: multiple first electrode plates 310 and multiple second electrode plates 320 are stacked alternately, with the diaphragm 330 interposed therebetween. Alternatively, the electrode assembly 300 may be a Z-stacked electrode assembly 300, wherein the first electrode plate 310 and the second electrode plate 320 are respectively inserted into both sides of the diaphragm 330, and then the structure is bent into a Z shape.

[0085] although Figure 6 The first electrode plate 310 and the second electrode plate 320 are shown as having the same dimensions, but these two electrode plates may have different dimensions. If the first electrode plate 310 and the second electrode plate 320 have different dimensions, overhangs may occur. For example, the area of ​​the negative electrode plate may be larger than the area of ​​the positive electrode plate.

[0086] Figure 6 This is a schematic illustration of a laminated structure of a stacked electrode assembly 300, and the number, size, or structure of the electrode plates may vary. The outermost layer of the electrode assembly 300 may be terminated by a first electrode plate 310 or a second electrode plate 320. The first electrode plate 310 may be formed as a positive electrode plate, and the second electrode plate 320 may be formed as a negative electrode plate, or vice versa.

[0087] According to one embodiment, when the first electrode plate 310 is formed as a positive electrode plate, a positive electrode active material layer mainly composed of lithium oxide can be coated on both sides of the thin aluminum foil that serves as the positive electrode current collector. Furthermore, uncoated portions of the positive electrode can be formed at both ends of the uncoated positive electrode active material layer of the positive electrode current collector.

[0088] The positive electrode plate for a rechargeable lithium battery may include a current collector and a layer of positive electrode active material on the current collector. The positive electrode active material layer may contain positive electrode active material and may further contain a binder and / or a conductive material (e.g., an electrically conductive material).

[0089] For example, the positive electrode plate may further include an additive capable of acting as a sacrificial positive electrode.

[0090] Based on a positive electrode active material layer of 100 wt%, the content of the positive electrode active material can be approximately 90 wt% to approximately 99.5 wt%. Based on a positive electrode active material layer of 100 wt%, the contents of the binder and conductive material can be approximately 0.5 wt% to approximately 5 wt%, respectively.

[0091] The binder is used to ensure good adhesion between positive electrode active material particles and to ensure good adhesion of the positive electrode active material to the current collector. As a non-limiting example, examples of binders may include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin, nylon, etc.

[0092] Conductive materials can be used to impart conductivity to electrodes. Any material that does not cause undesirable chemical changes and conducts electrons in rechargeable lithium batteries can be used. Examples of conductive materials can include: carbon-based materials such as natural graphite, synthetic graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, or carbon nanotubes; metallic materials containing copper, nickel, aluminum, or silver in the form of metal powder or metal fibers; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0093] Al foil can be used as a current collector, but is not limited to this.

[0094] The positive electrode active material may include compounds capable of intercalating and deintercalating lithium (lithiation intercalation compounds). Specifically, at least one lithium composite oxide containing a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0095] The composite oxide can be a lithium transition metal composite oxide. Specific examples of composite oxides may include lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free nickel manganese oxides, or combinations thereof.

[0096] As an example, the following compounds, represented by any of the following chemical formulas, can be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8,0≤b≤0.5, and 0≤c≤0.05); Lia Mn 2-b X b O 4-c D c (0.90≤a≤1.8,0≤b≤0.5, and 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8,0≤b≤0.9,0≤c≤0.5,0≤d≤0.5, and 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8 and 0.001≤b≤0.1);Li a CoG b O2(0.90≤a≤1.8 and 0.001≤b≤0.1);Li a Mn 1-b G b O2(0.90≤a≤1.8 and 0.001≤b≤0.1);Li a Mn2G b O4 (0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-g G g PO4 (0.90≤a≤1.8 and 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); and Li a FePO4 (0.90≤a≤1.8).

[0097] In the above chemical formulas: A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L1 It is Mn, Al, or a combination thereof.

[0098] The positive electrode active material can be, for example, a high-nickel positive electrode active material. Based on a lithium transition metal composite oxide containing 100 mol% of metals other than lithium, this high-nickel positive electrode active material has a nickel content of greater than or equal to about 80 mol%, greater than or equal to about 85 mol%, greater than or equal to about 90 mol%, greater than or equal to about 91 mol%, or greater than or equal to about 94 mol% and less than or equal to about 99 mol%. High-nickel positive electrode active materials can achieve high capacity and can be used in high-capacity, high-energy-density rechargeable lithium batteries.

[0099] According to one embodiment, when the second electrode plate 320 is formed as a negative electrode plate, the second electrode plate 320 may include a thin copper foil serving as a negative electrode current collector and a negative electrode active material layer containing carbon as the main component coated on both sides of the negative electrode current collector. Furthermore, the uncoated portion of the negative electrode may be formed at both ends of the uncoated negative electrode active material layer of the negative electrode current collector.

[0100] The negative electrode plate for a rechargeable lithium battery may include a current collector and a layer of negative electrode active material on the current collector. The negative electrode active material layer may contain negative electrode active material and may further contain a binder and / or a conductive material (e.g., an electrically conductive material).

[0101] For example, the negative electrode active material layer may contain about 90 wt% to about 99 wt% of negative electrode active material, about 0.5 wt% to about 5 wt% of binder, and about 0 wt% to about 5 wt% of conductive material.

[0102] The negative electrode current collector may include copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, or a combination thereof.

[0103] The negative electrode active material may include materials that can reversibly insert / deintercalate lithium ions, lithium metal, lithium metal alloys, materials that can be doped / dedoped with lithium, or transition metal oxides.

[0104] Materials that can reversibly insert / deintercalate lithium ions can include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, or combinations thereof. Crystalline carbon can be graphite, such as amorphous, tabular, flake, spherical, or fibrous natural or artificial graphite. Amorphous carbon can be soft carbon, hard carbon, mesophase pitch carbides, or calcined coke.

[0105] The lithium metal alloy may include an alloy of lithium and a metal selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn.

[0106] The material capable of doping / dedoping lithium may be a Si-based negative electrode active material or a Sn-based negative electrode active material. The Si-based negative electrode active material may include silicon, a silicon-carbon composite, SiO x (0 < x ≤ 2), or a Si-Q alloy (Q is selected from alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements (excluding Si), Group 15 elements, Group 16 elements, transition metals, rare earth elements, or a combination thereof). The Sn-based negative electrode active material may include Sn, SiO x (0 < x ≤ 2, such as SnO2), a Sn-based alloy, or a combination thereof.

[0107] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles. For example, the silicon-carbon composite may include secondary particles (cores) in which primary silicon particles are aggregated and an amorphous carbon coating layer (shells) on the surface of the secondary particles. Amorphous carbon may also be between the primary silicon particles; for example, the primary silicon particles may be coated with amorphous carbon. The secondary particles may be dispersed in the amorphous carbon matrix.

[0108] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles and an amorphous carbon coating layer on the surface of the core.

[0109] The Si-based negative electrode active material or the Sn-based negative electrode active material may be used in combination with a carbon-based negative electrode active material.

[0110] The separator 330 may include polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more layers thereof, and hybrid multilayer films such as a two-layer separator of polyethylene / polypropylene, a three-layer separator of polyethylene / polypropylene / polyethylene, a three-layer separator of polypropylene / polyethylene / polypropylene, etc.

[0111] The separator 330 may include a porous substrate and a coating layer containing an organic material, an inorganic material, or a combination thereof on one or two surfaces of the porous substrate.

[0112] The porous substrate can be a polymer film formed from any selection of polymers such as polyolefins (e.g., polyethylene and polypropylene), polyesters (e.g., polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber, or polytetrafluoroethylene (e.g., Teflon), or a copolymer or mixture thereof.

[0113] Organic materials may include polymers such as polyvinylidene fluoride or (meth)acrylic acid polymers.

[0114] Inorganic materials may include, but are not limited to, inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof.

[0115] Organic and inorganic materials can be mixed in a coating layer, or coating layers containing organic materials and coating layers containing inorganic materials can be stacked.

[0116] According to one embodiment, the electrode assembly 300 may include: a first electrode plate 310 having at least one first electrode tab 312 formed thereon; a second electrode plate 320 having at least one second electrode tab 322 formed thereon; and a diaphragm 330 located between the first electrode plate 310 and the second electrode plate 320.

[0117] According to one embodiment, at least one first electrode contact 312 can be formed as a pair of first electrode contact 312_1, 312_2 on one side of the first electrode plate 310, and at least one second electrode contact 322 can be formed as a pair of second electrode contact 322_1, 322_2 on one side of the second electrode plate 320. The first electrode contact 312 and the second electrode contact 322 can be formed by soldering the contact to the uncoated portions of the first electrode plate 310 and the second electrode plate 320, or by stamping the uncoated portions of the first electrode plate 310 and the second electrode plate 320.

[0118] According to one embodiment, in a stacked state, a pair of first electrode contacts 312_1 and 312_2 can be formed on one side of the electrode assembly 300, and a pair of second electrode contacts 322_1 and 322_2 can be formed on the other side of the electrode assembly 300. When the first electrode plate 310 is formed as a positive electrode plate, the pair of first electrode contacts 312_1 and 312_2 can be formed as positive electrode contacts, and when the second electrode plate 320 is formed as a negative electrode plate, the pair of second electrode contacts 322_1 and 322_2 can be formed as negative electrode contacts. If the polarities of the first electrode plate 310 and the second electrode plate 320 are interchanged, then of course it is also possible to form the pair of first electrode contacts 312_1 and 312_2 as negative electrode contacts and the pair of second electrode contacts 322_1 and 322_2 as positive electrode contacts.

[0119] Figure 7 An illustrative perspective view showing the connection state of the first electrode terminal and the first daughter board according to an embodiment of the present disclosure.

[0120] For ease of explanation, the description is based on the first electrode connector 312. Although not shown, the second electrode connector 322 can be described similarly to the first electrode connector 312.

[0121] refer to Figure 7 On one side of the electrode assembly 300, a pair of first electrode tabs 312_1 and 312_2 can protrude and be aligned. A first sub-plate 140 can be welded to the first electrode tabs 312, thereby electrically connecting the first electrode tabs 312 and the first sub-plate 140. In this case, to weld the first electrode tabs 312, the pair of first electrode tabs 312_1 and 312_2 can be bent in different directions. Then, the first sub-plate 140 can be tightly attached to the bent surfaces of the pair of first electrode tabs 312_1 and 312_2 and laser welded or ultrasonically welded.

[0122] For example, in a pair of first electrode terminals 312_1 and 312_2, reference Figure 7 The upper first electrode contact 312_1 can be bent to the left, and the lower first electrode contact 312_2 can be bent to the right. That is, the pair of first electrode contacts 312_1 and 312_2 on one side of the electrode assembly 300 can be bent in opposite directions.

[0123] After a pair of first electrode contacts 312_1 and 312_2 are bent and pressed in opposite directions, the first sub-board 140 can be located on the upper side of the pair of first electrode contacts 312_1 and 312_2, and the first plate portion 142 of the first sub-board 140 can be laser welded so that the first electrode contacts 312 and the first sub-board 140 are electrically connected.

[0124] Figure 8 This is an exploded perspective view illustrating an example of a first sub-board according to an embodiment of the present disclosure, and Figure 9 This is a perspective view showing an example of a first electrode terminal block and a first daughterboard being connected according to an embodiment of the present disclosure.

[0125] refer to Figure 8 and Figure 9 The first daughterboard 140 may include a first board portion 142 and a first connector portion 144, the first connector portion 144 having one end 144a connected to the first board portion 142 and one end connected to the first electrode terminal 130 (see [link]). Figure 5 The other end 144c of the first daughter plate 140 may include a first coating layer 146 formed by disposing the film 800 on at least a portion of the surface of the first terminal block portion 144. According to one embodiment, the first daughter plate 140 may contain a conductive material. For example, it may contain copper (Cu) or aluminum (Al), but the material of the first daughter plate 140 may vary.

[0126] According to one embodiment, the first plate portion 142 may include: a first welding portion 142a, and a first electrode terminal piece 312 (see [reference]). Figure 6 The electrode assembly 300 is welded to the first weld portion 142a; and a first protrusion 142b is connected to the first weld portion 142a and protrudes from the first weld portion 142a toward the first cover plate 120. That is, the first protrusion 142b may have a shape that protrudes in the Z-axis direction, which is opposite to the direction in which the electrode assembly 300 is located.

[0127] According to one embodiment, the first plate portion 142 may be electrically connected to the electrode assembly 300. Specifically, the first electrode terminal 312 of the electrode assembly 300 may be electrically connected to the front and / or rear surfaces of the first plate portion 142.

[0128] According to one embodiment, the width of the first plate portion 142 may be less than or equal to the thickness of the electrode assembly 300. Specifically, referring to the X-axis direction, the length of the first plate portion 142 may be less than or equal to the length of the electrode assembly 300.

[0129] According to one embodiment, the length of the first plate portion 142 may be less than or equal to the height of the electrode assembly 300. Specifically, referring to the Y-axis direction, the length of the first plate portion 142 may be less than or equal to the length of the electrode assembly 300.

[0130] According to one embodiment, the first welded portion 142a of the first plate portion 142 can be connected to the first electrode terminal piece 312 of the electrode assembly 300 by laser welding or ultrasonic welding. Correspondingly, the first sub-plate 140 can be connected to the first electrode terminal piece 312 of the electrode assembly 300 and can represent a positive electrode or a negative electrode.

[0131] According to one embodiment, the first protrusion 142b of the first plate portion 142 may be located between the two first welded portions 142a and may be located at the center of the first plate portion 142. That is, the two first welded portions 142a may be formed to be spaced apart from each other, with the first protrusion 142b located between them. Other components, such as insulating members, may be disposed below the first protrusion 142b.

[0132] According to one embodiment, the first connector portion 144 may have one end 144a that is welded to and connected to the first protrusion 142b, and the other end 144c of the first connector portion 144 may be welded to and connected to the first electrode terminal 130.

[0133] According to one embodiment, the width w1 of the first connector portion 144 may be less than or equal to the length of the first protrusion 142b. Specifically, referring to the Y-axis direction, the length of the first connector portion 144 may be less than or equal to the length of the first protrusion 142b.

[0134] According to one embodiment, the first connector portion 144 may include a first connecting portion 144b located between one end 144a of the first connector portion 144 that is soldered to the first protrusion 142b and the other end 144c of the first connector portion 144 that is soldered to the first electrode terminal 130. That is, the first connecting portion 144b may be an unsoldered area of ​​the first connector portion 144.

[0135] According to one embodiment, a first coating layer 146 may be formed to surround at least a portion of the first connecting portion 144b of the first tab portion 144. The first coating layer 146 may be formed by bonding a film (or adhesive film) 800. For example, the film 800 may be thermally bonded and adhered to the first connecting portion 144b.

[0136] According to one embodiment, the membrane 800 may include an adhesive layer 810 disposed on its surface facing the first connector portion 144. Accordingly, without additional processing, the membrane 800 can be readily configured to surround at least a portion of the first connector portion 144b, thereby forming a first coating layer 146.

[0137] According to one embodiment, the width w2 of the membrane 800 may correspond to (e.g., equal to) the perimeter (2w1 + 2t) of the first connecting portion 144b, which is twice the sum of the width w1 of the first connecting portion 144b and the thickness t of the first connecting portion 144b. Therefore, the membrane 800 may be configured to surround the first connecting portion 144b, thereby forming the first coating layer 146. Here, "corresponds" may mean that the width w2 of the membrane 800 is equal to or substantially equal to (within a certain permissible error range) the perimeter (2w1 + 2t) of the first connecting portion 144b.

[0138] According to one embodiment, the first coating layer 146 may comprise at least one of a heat-resistant material and a chemical-resistant material. The heat-resistant material may have excellent stability for long-term use in the high-temperature internal environment of the secondary battery. The chemical-resistant material may have low reactivity with the electrolyte contained in the secondary battery, thereby preventing premature deformation or decomposition.

[0139] In view of the above-mentioned heat resistance and chemical resistance, the first coating layer 146 may contain at least one of liquid crystal polymer (LCP), polyvinylidene fluoride (PVDF), polyether ether ketone (PEEK) and polyphenylene sulfide (PPS).

[0140] The first sub-board 140 can have various sizes and shapes.

[0141] Figure 10 An illustrative perspective view showing a state in which a first insulator is connected according to an embodiment of the present disclosure, and Figure 11 An example perspective view illustrating a first insulator being connected according to an embodiment of the present disclosure is shown.

[0142] refer to Figure 10 and Figure 11 The first insulator 150 may include: a first opening 154 through which a first terminal piece portion 144 of the first daughter plate 140 passes; and a plurality of first body portions 156, correspondingly formed to be spaced apart from each other, with the first opening 154 interposed therebetween. Here, the first body portions 156 may include through holes 152. The first insulator 150 may further include a first support portion 157, a first side portion 158, and a first fixing portion 159.

[0143] According to one embodiment, the first opening 154 may be located between the first protrusion 142b of the first plate portion 142 of the first sub-plate 140 and the first electrode terminal 130 (see [link]). Figure 4 )between.

[0144] According to one embodiment, a first main body portion 156 may be coupled to an electrode assembly 300 to cover a first plate portion 142 of a first sub-plate 140. The first main body portion 156 may be located on either side of a first opening 154 along the Y-axis direction. The first main body portion 156 may be located between a first welding portion 142a of the first plate portion 142 of the first sub-plate 140 and a first cover plate 120 (see [link]). Figure 4 )between.

[0145] According to one embodiment, the first main body portion 156 may cover the first welding portion 142a of the first plate portion 142 of the first sub-board 140, and the first terminal portion 144 of the first sub-board 140 and the first protrusion 142b of the first plate portion 142 may be exposed through the first opening 154. Furthermore, the first plate portion 142 of the first sub-board 140 may pass through the first insulator 150 via the first opening 154 and may be connected to the first electrode terminal 130.

[0146] According to one embodiment, a through-hole 152 may be formed in the first main body portion 156 on both sides, corresponding to the position of the electrolyte injection opening 122 of the first cover plate 120. For example... Figure 10 As shown, through-holes 152 can be formed in the two main body portions 156 on both sides. Accordingly, when electrolyte is injected through the first cover plate 120, the first insulator 150 can allow the electrolyte to move through the through-holes 152 into the interior of the electrode assembly 300.

[0147] According to one embodiment, the first support portion 157 may be formed in a rectangular ring shape along the outer periphery of both sides of the first main body portion 156. The first support portion 157 may be formed in the Z-axis direction (towards the first cover plate 120, see...) Figure 4 The first support portion 157 has a certain height from the first main body portion 156. This "certain height" can correspond to the distance between the first sub-plate 140 and the first cover plate 120 connected to the electrode assembly 300. Therefore, the first support portion 157 can prevent the electrode assembly 300 from moving along the Z-axis inside the housing 110.

[0148] According to one embodiment, the first side portion 158 may be configured to connect and secure the two sides of the first support portion 157. The first side portion 158 may be located on both sides of the first opening 154 along the X-axis direction.

[0149] According to one embodiment, the first fixing portion 159 may be formed to protrude from the first side portion 158 toward the first sub-plate 140. The first fixing portion 159 may have a hook shape, and at least a pair of first fixing portions 159 may be formed symmetrically. Therefore, the first fixing portion 159 may be connected to the first protrusion 142b of the first plate portion 142 of the first sub-plate 140. Accordingly, the first insulator 150 may be fixed to the first sub-plate 140.

[0150] Figure 12 A perspective view illustrating an example of the connection between a first cover plate and a first electrode terminal according to an embodiment of the present disclosure.

[0151] refer to Figure 12 After connecting the first insulator 150, the first terminal piece 144 can be connected to the first current collector 136. The first terminal piece 144 can be connected to the first current collector 136 by welding. Accordingly, the first terminal piece 144 can be connected to the first cover plate 120 to which the first current collector 136 is connected. Then, the first terminal piece 144 having the first coating layer 146 disposed thereon can be bent at least once and the open side of the housing 110 can be sealed by the first cover plate 120.

[0152] Figure 13 A perspective view illustrating an example of a first connector portion in an unfolded state according to an embodiment of the present disclosure.

[0153] refer to Figure 13 The first terminal portion 144 may include one end 144a, a first connecting portion 144b, another end 144c, and a first coating layer 146. The first coating layer 146 may be configured to surround at least a portion of the first connecting portion 144b.

[0154] According to one embodiment, when the first connector portion 144 is in the unfolded state, in the Z-axis direction, the length L1 of one end 144a of the first connector portion 144 can be 10% to 30% of the total length L4 of the first connector portion 144. Specifically, in the Z-axis direction, the length L1 of one end 144a of the first connector portion 144 can be 10% to 30% of the total length L4 of the first connector portion 144.

[0155] According to one embodiment, when the first connector portion 144 is in the unfolded state, in the Z-axis direction, the length L2 of the first connector portion 144 welded to the other end 144c of the first electrode terminal 130 can be 10% to 30% of the total length L4 of the first connector portion 144.

[0156] According to one embodiment, when the first connector portion 144 is in the unfolded state, the length L3 of the first connecting portion 144b in the Z-axis direction can be 40% to 80% of the total length L4 of the first connector portion 144.

[0157] The electrodes and electrode terminals of the electrode assembly can be electrically connected via a daughterboard. The daughterboard can electrically connect the electrodes and electrode terminals by contacting the electrode tabs. In some forms of the daughterboard, a tab portion formed of a thin metal plate may be included. The tab portion may deform due to external impact and / or vibration. In this case, the tab portion may break and cause a short circuit.

[0158] According to some embodiments of this disclosure, a secondary battery with improved safety can be provided.

[0159] According to some embodiments of this disclosure, by providing a first coating layer on the first terminal piece portion of the first sub-board, the first terminal piece portion can be reinforced and damage to the first terminal piece portion that may occur due to external impact can be prevented.

[0160] Although the present disclosure has been described above with respect to embodiments thereof, the present disclosure is not limited thereto. Various modifications and variations can be made by those skilled in the art without departing from the spirit of the present disclosure and the equivalent scope of the appended claims.

[0161] Example embodiments have been disclosed herein. Although specific terminology has been used, it is used and interpreted in a general and descriptive sense only and is not intended to be limiting. In some instances, as will be apparent to those skilled in the art at the time of filing this application, unless specifically instructed otherwise, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments. Accordingly, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the claims.

Claims

1. A secondary battery, comprising: An electrode assembly, including a first electrode terminal on one side and a second electrode terminal on the other side; A housing having at least one open side, the housing accommodating the electrode assembly; A first cover plate is attached to an open side of the housing; The first electrode terminal is electrically connected to the first electrode connector, and the first electrode terminal is exposed outside the first cover plate; The first daughterboard is electrically connected to the first electrode connector and the first electrode terminal; as well as A first insulator is located between the first cover plate and the electrode assembly. The first sub-board includes: The first plate portion is connected to the first electrode terminal piece; The first connector portion has one end connected to the first plate portion and the other end connected to the first electrode terminal; and The first coating layer is applied to at least a portion of the surface of the first terminal piece.

2. The secondary battery according to claim 1, wherein the first plate portion comprises: The first welding part is welded to the first electrode terminal piece; as well as A first protruding portion is connected to the first welded portion, and the first protruding portion protrudes in a direction from the first welded portion toward the first cover plate.

3. The secondary battery according to claim 2, wherein the first welded portion is provided as a plurality of first welded portions, the plurality of first welded portions being spaced apart from each other, and the first protrusion being located therebetween.

4. The secondary battery according to claim 2, wherein: The first terminal piece is welded to the first protrusion at one end, and The first terminal piece is soldered to the first electrode terminal at the other end.

5. The secondary battery of claim 4, wherein the first terminal portion includes a first connection portion between one end of the first terminal portion welded to the first protrusion and the other end of the first terminal portion welded to the first electrode terminal.

6. The secondary battery according to claim 5, wherein when the first terminal piece is in the unfolded state, the length of the first terminal piece welded to one end of the first protrusion is 10% to 30% of the total length of the first terminal piece.

7. The secondary battery according to claim 5, wherein when the first connecting piece portion is in the unfolded state, the length of the first connecting piece portion welded to the other end of the first electrode terminal is 10% to 30% of the total length of the first connecting piece portion.

8. The secondary battery according to claim 5, wherein when the first terminal piece is in the unfolded state, the length of the first connecting portion is 40% to 80% of the total length of the first terminal piece.

9. The secondary battery of claim 5, wherein the first coating layer surrounds at least a portion of the first connection portion of the first terminal block portion.

10. The secondary battery of claim 5, wherein the first terminal portion bends at least once at the first connection portion on which the first coating layer is located.

11. The secondary battery according to claim 5, wherein the first coating layer is an adhesive film.

12. The secondary battery according to claim 11, wherein the width of the adhesive film corresponds to the perimeter of the first connecting portion, the perimeter being twice the sum of the width of the first connecting portion and the thickness of the first connecting portion.

13. The secondary battery of claim 11, wherein the adhesive film comprises an adhesive layer on the surface of the adhesive film facing the first terminal piece portion.

14. The secondary battery according to claim 1, wherein the first coating layer comprises at least one of a heat-resistant material and a chemical-resistant material.

15. The secondary battery according to claim 1 or 14, wherein the first coating layer comprises at least one selected from liquid crystal polymer, polyvinylidene fluoride, polyetheretherketone, and polyphenylene sulfide.

16. The secondary battery according to claim 1, wherein the first insulator comprises: The first opening is through which the first terminal piece of the first sub-board passes; as well as Multiple first main body parts are spaced apart from each other, and the first opening is located between them.

17. The secondary battery according to claim 1, wherein the first electrode terminal comprises: A first current collector has a through hole on the surface of the first cover plate facing the electrode assembly; A first terminal plate, having a through hole on a surface of the first cover plate opposite to the surface facing the electrode assembly; and A first rivet engages the through hole of the first current collector and the through hole of the first terminal plate, and the first rivet penetrates the first cover plate.

18. The secondary battery according to claim 1, further comprising: The second cover plate is connected to the other open side of the housing; The second electrode terminal is electrically connected to the second electrode connector, and the second electrode terminal is exposed outside the second cover plate; The second daughterboard is electrically connected to the second electrode terminal and the second electrode connector; as well as A second insulator is located between the second cover plate and the electrode assembly.

19. The secondary battery according to claim 18, wherein the second sub-plate comprises: The second plate is connected to the second electrode terminal piece; The second connector portion has one end connected to the second plate portion and the other end connected to the second electrode terminal; as well as The second coating layer is applied to at least a portion of the surface of the second terminal piece.

20. The secondary battery according to claim 19, wherein: The second connector portion includes a second connection portion between one end of the second connector portion that is soldered to the second plate portion and the other end of the second connector portion that is soldered to the second electrode terminal, and The second coating layer surrounds at least a portion of the second connection portion.

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