Secondary battery, secondary battery manufacturing method, and secondary battery module

Abstract

The invention relates to a secondary battery, a secondary battery manufacturing method and a secondary battery module. The technical problem to be solved is to propose a current path simplification structure for solving the problems of cost increase and performance reduction caused by various components constituting a current path of the secondary battery. To this end, the present invention provides a secondary battery, a method of manufacturing the same, and a vehicle including the same, the secondary battery comprising: a plurality of electrode plates included in the electrode assembly; a plurality of electrode tabs extending from the plurality of electrode plates; a daughter board coupled to the plurality of electrode tabs; a cover plate in which a through-hole is formed, a peripheral portion forming the through-hole protrudes, and the daughter plate penetrates through the through-hole and is coupled to the cover plate; and a sealing member which is formed on the cover plate so as to surround a protruding peripheral portion of the through-hole through which the daughter plate passes, and which seals a joint portion between the cover plate and the daughter plate.

Description

Technical Field

[0001] The present invention relates to a secondary battery, and more particularly to a secondary battery in which a component constituting a current path of the secondary battery is replaced with a sub-plate and sealed with a sealing member. Background Art

[0002] Unlike non-rechargeable primary batteries, secondary batteries are batteries that can be charged and discharged. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, notebook computers, digital cameras, and video cameras, while large-capacity secondary batteries are widely used as motor drive power sources and power storage batteries for hybrid vehicles, electric vehicles, and the like.

[0003] Generally, a secondary battery includes an electrode assembly composed of a positive electrode and a negative electrode, a case accommodating the electrode assembly, a terminal portion connected to the electrode assembly, various components connecting the terminal portion and the electrode assembly, and the like.

[0004] The above information disclosed in this art forming the background of the invention is only for enhancement of understanding of the background of the invention and therefore may include information that does not constitute the prior art. Summary of the Invention

[0005] Secondary batteries include various components, such as terminal plates, rivets, current collectors, and lower insulating members, that form a current path between the terminal portion and the electrode assembly. The manufacturing and assembly of these components increases costs, and the current path through these components increases resistance, which can reduce secondary battery performance. Therefore, a simplified current path structure is proposed to reduce secondary battery cost and improve performance.

[0006] However, the technical problems to be solved by the present invention are not limited to the above-mentioned technical problems, and those skilled in the art can clearly understand other technical problems not mentioned from the description of the invention described below.

[0007] A secondary battery according to an embodiment of the present invention for solving the above-mentioned technical problems includes an electrode assembly and a shell for accommodating the electrode assembly, and the secondary battery may include: a plurality of electrode plates included in the electrode assembly; a plurality of electrode tabs extending from the plurality of electrode plates; a sub-plate combined with the plurality of electrode tabs; a cover plate formed with a through hole, the peripheral portion of the through hole being protruded, the sub-plate passing through the through hole and combined with the cover plate; and a sealing component formed on the cover plate in a manner of surrounding the protruding peripheral portion of the through hole passed by the sub-plate, and sealing the joint between the cover plate and the sub-plate.

[0008] Furthermore, a secondary battery manufacturing method according to another aspect of the present invention for solving the above-mentioned technical problems may include the following steps: manufacturing an electrode assembly including a plurality of electrode plates; coupling a plurality of electrode tabs extending from the plurality of electrode plates to a sub-plate; coupling the sub-plate to the cover plate by allowing the sub-plate to pass through the through-hole formed in the cover plate with the protruding peripheral portion of the through-hole; forming a sealing component for sealing the joint between the cover plate and the sub-plate in a manner that surrounds the protruding peripheral portion of the through-hole passed by the sub-plate; and accommodating the electrode assembly in a shell and coupling the cover plate to the shell.

[0009] According to still another aspect of the present invention, there is provided a vehicle including a secondary battery pack manufactured using the secondary battery having the above configuration.

[0010] According to the embodiment of the present invention, components constituting the current path of the secondary battery are replaced with a sub-board, thereby having the effects of reducing the cost of the secondary battery as components are reduced and improving performance by reducing the resistance path length.

[0011] In particular, by removing components such as the terminal plate, rivets, current collector, and lower insulating member that constitute the current path between the terminal portion and the electrode assembly, and removing assembly processes such as welding or riveting, the production cost of the secondary battery can be reduced.

[0012] Furthermore, the contact resistance between components decreases as the number of components decreases, and the component resistance decreases as the current path shortens, thereby having an effect of improving the performance of the secondary battery.

[0013] Furthermore, in a vehicle using the secondary battery of the present invention, the cost of the secondary battery, which accounts for the largest proportion of the vehicle price, can be reduced while improving performance, thereby improving performance such as driving performance and mileage while reducing the vehicle price.

[0014] However, the effects that can be obtained by the present invention are not limited to the above-mentioned effects, and those skilled in the art can clearly understand other technical effects that are not mentioned from the description of the invention described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The following drawings attached to this specification illustrate preferred embodiments of the present invention and are used to further understand the technical concept of the present invention in conjunction with the detailed description of the invention described later. Therefore, the present invention should not be interpreted as being limited to the matters described in the drawings.

[0016] Figure 1a This is a perspective view of the upper portion of a conventional prismatic secondary battery.

[0017] Figure 1b yes Figure 1a II′ cross-sectional view.

[0018] Figure 2a FIG. 1 is a side cross-sectional view of a secondary battery according to an embodiment of the present invention.

[0019] Figure 2b FIG. 1 is a plan view of a secondary battery according to an embodiment of the present invention.

[0020] Figure 2c FIG. 1 is a top front view of a secondary battery according to an embodiment of the present invention.

[0021] Figure 3a FIG. 1 is a side cross-sectional view of a sealing member of a secondary battery according to an embodiment of the present invention.

[0022] Figure 3b FIG. 1 is a diagram showing a first embodiment of a sealing member for a secondary battery according to an embodiment of the present invention.

[0023] Figure 3c FIG. 1 is a diagram showing a second embodiment of the sealing member of the secondary battery according to the embodiment of the present invention.

[0024] Figure 3d FIG. 1 is a diagram showing a third embodiment of the sealing member of the secondary battery according to the embodiment of the present invention.

[0025] Figure 4a A diagram showing a current path in a conventional prismatic secondary battery.

[0026] Figure 4b It is a plan view showing a terminal portion of a conventional prismatic secondary battery.

[0027] Figure 4c This is a front view showing a terminal portion of a conventional prismatic secondary battery.

[0028] Figure 5a FIG. 1 is a diagram illustrating a current path of a secondary battery according to an embodiment of the present invention.

[0029] Figure 5b FIG. 1 is a plan view of a terminal portion of a secondary battery according to an embodiment of the present invention.

[0030] Figure 5c FIG. 1 is a front view of a terminal portion of a secondary battery according to an embodiment of the present invention.

[0031] Figures 6a to 6f 1 is a diagram for explaining a method for manufacturing a secondary battery according to an embodiment of the present invention.

[0032] Figure 7 FIG. 1 is an exemplary diagram illustrating a secondary battery module in which secondary batteries are arranged according to an embodiment of the present invention.

[0033] Figure 8 is included Figure 7 An exemplary diagram of a secondary battery pack of the illustrated secondary battery module.

[0034] Figure 9 is included Figure 8 A conceptual diagram of a vehicle illustrating an example of a secondary battery pack. DETAILED DESCRIPTION

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before describing, the terms or words used in this specification and claims should not be interpreted as limited to their general or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical ideas of the present invention based on the principle that the inventor may appropriately define the concepts of terms in order to explain his invention in the best way. Therefore, the embodiments described in this specification and the structures shown in the accompanying drawings are only the most preferred partial embodiments of the present invention and do not represent the entire technical ideas of the present invention. Therefore, it should be understood that at the time of this application, there may be a variety of equivalents and modifications that can replace these.

[0036] Furthermore, when used in this specification, “comprise” and / or “comprising” and / or “including” are used to indicate the existence of specific shapes, numbers, steps, operations, parts, elements and / or combinations thereof, and do not exclude the existence or addition of one or more other shapes, numbers, operations, parts, elements and / or combinations thereof.

[0037] In addition, in order to help understand the invention, the accompanying drawings are not drawn to scale, but the sizes of some components may be exaggerated. In addition, in different embodiments, the same components may be given the same reference numerals.

[0038] When two comparison objects are referred to as "the same," it means "substantially the same." Therefore, "substantially the same" may include cases where there is a deviation that is considered to be relatively low in the art, for example, within 5%. Furthermore, "uniformity" of certain parameters in a predetermined region may mean uniformity from an average perspective.

[0039] Although the terms "first," "second," etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from other components. Unless otherwise specified, the first component can also be the second component.

[0040] Throughout the specification, unless otherwise specified, each component may be in the singular or the plural.

[0041] Arranging an arbitrary component "on the top (or bottom)" of a component or "above (or below)" a component not only means that the arbitrary component is arranged in contact with the top (or bottom) of the component, but also means that other components may be interposed between the component and the arbitrary component arranged above (or below) the component.

[0042] Furthermore, when it is described that a certain component is “on,” “connected to,” or “coupled to” another component, the components may be directly connected or coupled to each other, but it should be understood that another component may be “interposed” between the components, or the components may be “connected,” “coupled,” or “coupled” through another component.

[0043] As used in this specification, the term "and / or" includes any and all combinations of more than one of the associated listed items. In addition, the term "may" used in describing embodiments of the present invention refers to "one or more embodiments of the present invention." The phrase "one or more" and expressions such as "one or more" preceding an item in a list modify the entire item in the list, not the individual items in the list.

[0044] Throughout the specification, when "A and / or B" is mentioned, it means A, B, or A and B unless otherwise stated. When "C to D" is mentioned, it means C or more and D or less unless otherwise stated.

[0045] When statements 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 specify items of A, B, and C, the statements may refer to any and all suitable combinations.

[0046] The term "use" may be considered synonymous with the term "utilize." As used in this specification, the terms "substantially," "about," and similar terms are used as terms of approximation rather than degree, and are intended to take into account the inherent variations in measured or calculated values ​​that one of ordinary skill in the art would recognize.

[0047] Although the terms first, second, third, etc. may be used in this specification to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. The terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or part discussed below may be referred to as a second element, component, region, layer, or part.

[0048] To illustrate the relationship between one element or feature as shown in the figures and another element or feature, spatially relative terms such as "beneath," "below," "lower," "above," and "upper" may be used in the specification for ease of description. It should be understood that spatial relative positions include not only the orientation depicted in the figures, but also different orientations of the device during use or operation. For example, if the device in the figure is turned over, other elements are understood to be "below" or "below" the other elements, and the illustrated elements are understood to be "above" or "upper" the other elements. Therefore, the term "below" can encompass both directions of above and below.

[0049] The terms used in this specification are used to describe the embodiments of the present invention and are not intended to limit the present invention.

[0050] Types of secondary batteries include coin type, cylindrical type, prismatic type, and pouch type. Since the present invention is basically applicable to prismatic secondary batteries, a prismatic secondary battery will be schematically described first before describing embodiments of the present invention.

[0051] Figure 1a This is a perspective view of the upper part of a conventional prismatic secondary battery. Figure 1b yes Figure 1a II′ cross-sectional view.

[0052] First, yes Figure 1a The appearance of the conventional prismatic secondary battery shown will be described.

[0053] The case 51 forms the overall appearance of the prismatic secondary battery and may be formed using a conductive metal such as aluminum, an aluminum alloy, or nickel-plated steel. In addition, the case 51 may provide a space for accommodating the electrode assembly.

[0054] The cover assembly 60 may include a cover plate 61 covering the opening of the housing 51. The housing 51 and the cover plate 61 may be made of a conductive material. Here, the first terminal 62 and the second terminal 63 may be configured to be electrically connected to the positive or negative electrode inside and extend through the cover plate 61 to protrude outward.

[0055] The cover plate 61 may be formed with an electrolyte injection port 64 to which a sealing plug may be provided, and may be provided with a vent 66 having a notch 65. The vent 66 is used to degas the gas generated inside the battery.

[0056] Reference Figure 1b , the internal structure of the prismatic secondary battery and the coupling structure with the cap assembly 60 are described.

[0057] Figure 1b The illustrated prismatic secondary battery may basically include an electrode assembly 40 , a first current collecting portion 41 , a first terminal 62 , a second current collecting portion 42 , a second terminal 63 , and a cap assembly 60 .

[0058] The electrode assembly 40 can be formed by winding or stacking a stack of a first electrode plate, a separator, and a second electrode plate formed into a plate shape or a film shape. When the electrode assembly 40 is a wound stack, the winding axis can be parallel to the length direction of the shell 51. In addition, the electrode assembly 40 can be a stacked type instead of a wound type, but in the present invention, the shape of the electrode assembly 40 is not limited. In addition, the electrode assembly 40 can be a Z-stacked electrode assembly in which the first electrode plate and the second electrode plate are inserted into both sides of the separator bent into a Z stack. In addition, the electrode assembly 40 can be one or more electrode assemblies whose long sides are stacked adjacent to each other and housed inside the shell, and in the present invention, the number of electrode assemblies is not limited. The first electrode plate of the electrode assembly 40 can play the role of a negative electrode, and the second electrode plate can play the role of a positive electrode, and vice versa.

[0059] The first electrode plate can be formed by coating a first electrode current collecting plate formed from a metal foil such as copper, copper alloy, nickel, or nickel alloy with a first electrode active material such as graphite or carbon, and can include a first electrode tab (or first uncoated portion) as an area not coated with the first electrode active material. The first electrode tab 43 can serve as a path for current flow between the first electrode plate and the first current collecting portion 41. In some examples, when manufacturing the first electrode plate, the first electrode tab 43 can be pre-cut to protrude toward one side, and can protrude further toward one side than the separator without being separately cut.

[0060] The second electrode plate can be formed by coating a second electrode active material, such as a transition metal oxide, on a substrate formed of a metal foil such as aluminum or an aluminum alloy. The second electrode plate can include a second electrode tab (or second uncoated portion) 44, which is a region not coated with the second electrode active material. The second electrode tab 44 can serve as a path for current flow between the second electrode plate and the second current collecting portion 42. In some examples, when manufacturing the second electrode plate, the second electrode tab 44 can be pre-cut to protrude toward the other side and can protrude further than the separator without being separately cut.

[0061] In some embodiments, the first electrode tab 43 may be located on the right side of the electrode assembly 40, and the second electrode tab 44 may be located on the left side of the electrode assembly 40, or may be located on a side in the same direction. Here, the left and right sides are based on the secondary battery shown in FIG1 for ease of description. When the secondary battery is rotated left or right or up or down, their positions may change.

[0062] The separator allows lithium ions to move while preventing a short circuit between the first electrode plate and the second electrode plate. The separator can be formed using, for example, a polyethylene film, a polypropylene film, or a polyethylene-polypropylene film.

[0063] The first electrode tab 43 of the first electrode plate and the second electrode tab 44 of the second electrode plate extend from both side ends of the electrode assembly 40. In some embodiments, the electrode assembly 40 may be housed in a housing 51 together with the electrolyte.

[0064] In the electrode assembly 40 , first and second electrode tabs 43 and 44 extending from the first and second electrode plates to both sides are connected to the first and second current collecting portions 41 and 42 , respectively, by welding.

[0065] The first current collecting portion 41 and the second current collecting portion 42 are connected to the first current collecting portion 41 and the second current collecting portion 42 through the terminal pins 67 Figure 2a The first terminal 62 and the second terminal 63 described in the foregoing are connected. In some embodiments, the outer peripheral surface of the terminal pin 67 may be threaded and fastened to the first terminal 62 and the second terminal 63 by threaded engagement. However, the present invention is not limited thereto, and the terminal pin 67 may also be coupled to the first terminal 62 and the second terminal 63 by riveting or welding.

[0066] According to one embodiment of the present invention, a secondary battery having Figure 1a and Figure 1b The structure of the conventional prismatic secondary battery shown is different from that of the secondary battery. Figures 2a to 2cThe structure of a secondary battery according to one embodiment of the present invention will be described.

[0067] Figure 2a is a side sectional view of a secondary battery according to one embodiment of the present invention, Figure 2b is a plan view of a secondary battery according to an embodiment of the present invention, Figure 2c FIG. 1 is a top front view of a secondary battery according to an embodiment of the present invention.

[0068] Reference Figures 2a to 2c A secondary battery 100 according to an embodiment of the present invention includes an electrode assembly 110 , a case 120 accommodating the electrode assembly 110 , a plurality of electrode tabs 130 , a sub-plate 140 , a cap plate 150 , and a sealing member 160 .

[0069] The electrode assembly 110 includes a plurality of electrode plates 111 and a separator 112, and can be formed by winding or stacking a plurality of electrode plates 111 and separators 112 formed in a plate shape or a film shape. In the case where the electrode assembly 110 is a wound stack, the winding axis can be parallel to the length direction of the shell. In addition, the electrode assembly 110 can be a stacked type rather than a wound type, but in the present invention, the shape of the electrode assembly 110 is not limited. In some embodiments, the electrode assembly 110 can be accommodated in the shell 120 together with the electrolyte.

[0070] The plurality of electrode plates 111 may have positive or negative polarity depending on the polarity of the corresponding terminals. In addition, the plurality of electrode plates 111 may include a coated portion coated with an active material and an uncoated portion not coated with the active material. In the case where the plurality of electrode plates 111 are negative electrodes, the plurality of electrode plates 111 may be formed by coating a metal foil such as copper, a copper alloy, nickel, or a nickel alloy with an active material such as graphite or carbon. In the case where the plurality of electrode plates 111 are positive electrodes, the plurality of electrode plates 111 may be formed by coating a metal foil such as aluminum or an aluminum alloy with an active material such as a transition metal oxide.

[0071] The separator 112 allows lithium ions to move while preventing short circuits between the plurality of electrode plates 111. The separator 112 can be formed of, for example, a polyethylene film, a polypropylene film, or a polyethylene-polypropylene film.

[0072] The case 120 forms the overall appearance of the prismatic secondary battery and may be formed using a conductive metal such as aluminum, an aluminum alloy, or nickel-plated steel. In addition, the case 120 may provide a space for accommodating the electrode assembly 110 .

[0073] The plurality of electrode tabs 130 extend from the plurality of electrode plates 111. In one embodiment, the plurality of electrode tabs 130 may extend from uncoated portions of the plurality of electrode plates 111.

[0074] The plurality of electrode tabs 130 are coupled to a sub-plate 140. The sub-plate 140 collects current transmitted from the electrode assembly 110 through the plurality of electrode tabs 130 and transmits it to the outside. In one embodiment, the sub-plate 140 can be made of the same material as the plurality of electrode plates 111 and the plurality of electrode tabs 130. Furthermore, in one embodiment, the sub-plate 140 can be coupled to the plurality of electrode tabs 130 by laser welding.

[0075] The cover plate 150 is combined with the sub-plate 140 by allowing the sub-plate 140 to pass through the cover plate 150. The cover plate 150 may be formed with a through hole for allowing the sub-plate 140 to pass through, and the peripheral portion of the through hole may be protruding. In one embodiment, the peripheral portion of the through hole of the cover plate 150 through which the sub-plate 140 passes may be protruding in a curved surface. Since the peripheral portion of the through hole of the cover plate 150 is protruding in a curved surface, the sealing component 160 described later can effectively seal the joint between the cover plate 150 and the sub-plate 140. The cover plate 150 has a roughly rectangular plate shape. The cover plate 150 covers the opening of the shell 120. For example, the cover plate 150 may be coupled to the shell 120 by methods such as laser welding. Similar to the shell 120, the cover plate 150 may be formed using a conductive material.

[0076] Sealing member 160 is formed to surround the protruding peripheral portion of the through-hole of cap plate 150 through which sub-plate 140 passes, and seals the joint between cap plate 150 and sub-plate 140. Sealing member 160 is used to prevent liquid such as electrolyte within the secondary battery or gas generated by internal chemical reactions from leaking out of the secondary battery.

[0077] Below, refer to Figures 3a to 3d , the structure, function and embodiment of the sealing component 160 are described.

[0078] Figure 3a is a side sectional view of a sealing member of a secondary battery according to one embodiment of the present invention, Figure 3b 1 is a diagram showing a first embodiment of a sealing member for a secondary battery according to an embodiment of the present invention, Figure 3c 1 is a diagram showing a second embodiment of the sealing member of the secondary battery according to one embodiment of the present invention, Figure 3d FIG. 1 is a diagram showing a third embodiment of the sealing member of the secondary battery according to the embodiment of the present invention.

[0079] Reference Figure 3a The sealing member 160 of the secondary battery 100 according to an embodiment of the present invention may include an inner compression material 161 , an outer compression material 162 , and a fastening member 163 .

[0080] Internal compression material 161 is placed in the space between the through-holes of sub-plate 140 and cover plate 150. External compression material 162 surrounds the joint between sub-plate 140 and cover plate 150, and fastening member 163 surrounds external compression material 162. Internal and external compression materials 161, 162 are made of a polymeric compression material such as rubber or silicone, and fastening member 163 surrounds the exterior, ensuring a secure seal.

[0081] Reference Figures 3b to 3d The sealing member 160 of the secondary battery 100 according to an embodiment of the present invention may further include an adjusting member 164 provided at a portion of the fastening member 163 to adjust the degree of fastening of the fastening member 163. The adjusting member 164 may secure the sealing force of the sealing member 160 by clamping the fastening member 163.

[0082] In addition, the sealing member 160 can also simultaneously perform a vent function to release the seal and exhaust gas when the predetermined internal pressure increases in addition to performing a sealing function. At this time, the adjustment member 164 controls the degree of tightening of the fastening member 163 to a predetermined level, thereby being able to adjust the breaking pressure at which the seal is released.

[0083] like Figure 3b As shown, the adjustment member 164 may be a clamp formed on one side, such as Figure 3c As shown, the adjusting components 164-1 and 164-2 can be clamps formed on both sides. In the case of this clamping method, the sealing force and the breaking force can be controlled by adjusting the torque of the tightening screw.

[0084] like Figure 3d As shown, the adjusting member 164 can be a cable tie. In the case of this cable tie mode, the tightening force, sealing force and breaking pressure can be controlled by adjusting the pulling force.

[0085] The structure of the secondary battery according to one embodiment of the present invention has been described above. Figures 4a to 5c Advantageous effects resulting from structural differences between a secondary battery according to an embodiment of the present invention and a conventional prismatic secondary battery will be described.

[0086] Figure 4a is a diagram showing a current path of a conventional prismatic secondary battery. Figure 4b is a plan view showing a terminal portion of a conventional prismatic secondary battery. Figure 4c This is a front view showing a terminal portion of a conventional prismatic secondary battery.

[0087] Reference Figures 4a to 4c, the current path of the previous prismatic secondary battery includes the terminal plate 210, the rivet 220, the current collector 230, the sub-tab 240 and the lower insulating component 250. In the previous prismatic secondary battery, in the case of the negative terminal, the electron movement path is from the electrode assembly through the sub-tab 240, the current collector 230 and the rivet 220 and is transmitted to the outside through the terminal plate 210. In this way, since the current path of the previous prismatic secondary battery passes through various components, contact resistance is generated between the components, and the current path becomes longer and the component resistance increases, thereby affecting the performance of the secondary battery. In addition, as various components are used, the cost of the secondary battery also increases.

[0088] Figure 5a is a diagram showing a current path of a secondary battery according to an embodiment of the present invention, Figure 5b is a plan view of a terminal portion of a secondary battery according to an embodiment of the present invention, Figure 5c FIG. 1 is a front view of a terminal portion of a secondary battery according to an embodiment of the present invention.

[0089] Reference Figures 5a to 5c , the current path of the secondary battery according to an embodiment of the present invention is composed only of a plurality of electrode tabs 130 and a sub-plate 140. In the secondary battery according to an embodiment of the present invention, in the case of the negative terminal, the movement path of the electrons is directly transmitted from the electrode assembly 110 to the outside through the plurality of electrode tabs 130 and the sub-plate 140. In this way, in the current path of the secondary battery according to an embodiment of the present invention, all components such as the terminal plate, rivets, current collector, lower insulating component, etc. that constitute the current path between the terminal portion and the electrode assembly are removed, so that the contact resistance between the components decreases as the number of components is reduced, and the component resistance decreases as the current path becomes shorter, thereby improving the performance of the secondary battery. In addition, by removing the components that constitute the current path and removing assembly processes such as welding or riveting, the production cost of the secondary battery can be reduced.

[0090] Figures 6a to 6f 1 is a diagram for explaining a method for manufacturing a secondary battery according to an embodiment of the present invention.

[0091] Reference Figure 6a , an electrode assembly 110 including a plurality of electrode plates 111 is manufactured. At this time, a plurality of electrode tabs 130 may be provided extending from the plurality of electrode plates 111 .

[0092] Reference Figure 6b and Figure 6c The plurality of electrode tabs 130 extending from the plurality of electrode plates 111 are coupled to the sub-plate 140. Figure 6bIn the embodiment of the present invention, the plurality of electrode tabs 130 may be bent toward the sub-plate 140 so that the plurality of electrode tabs 130 are in contact with the sub-plate 140. Figure 6c In the embodiment, the plurality of electrode tabs 130 and the sub-plate 140 may be combined by laser welding.

[0093] Reference Figure 6d The through hole formed in the cover plate 150 and the protruding peripheral portion of the through hole allows the sub-plate 140 to pass through and be coupled to the cover plate 150. Figure 6d In the embodiment, the sub-board 140 may be coupled to the cover plate 150 by penetrating the through hole of the cover plate 150 with a curved protruding surface at the periphery of the through hole.

[0094] Reference Figure 6e The sealing member 160 for the joint between the cover plate 150 and the sub-plate 140 is formed in such a manner as to surround the protruding peripheral portion of the through hole through which the sub-plate 140 passes. Figure 6e In the embodiment, an internal compressive material 161 is provided in the space between the through-holes of the sub-plate 140 and the cover plate 150, and an external compressive material 162 is used to surround the periphery of the junction between the sub-plate 140 and the cover plate 150. Furthermore, a fastening member 163 may be used to surround the external compressive material 162, and an adjustment member 164 for adjusting the degree of tightening of the fastening member 163 may be provided on a portion of the fastening member 163.

[0095] Reference Figure 6f , the electrode assembly 110 is housed in the housing 120, and the cap plate 150 and the housing 120 are combined. Figure 6f In the embodiment, the cover plate 150 and the housing 120 may be welded together.

[0096] Hereinafter, materials that can be used in the secondary battery according to the present invention will be described.

[0097] As the positive electrode active material, a compound capable of reversibly intercalating and deintercalating lithium (lithiated intercalation compound) can be used. Specifically, one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0098] The composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, cobalt-free nickel manganese-based oxides, or combinations thereof.

[0099] As an example, a compound represented by any one of the following chemical formulas can be used. a A 1-b X b O 2-c D c(0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05);Li a Mn 2-b X b About 4-c D c (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05);Li a Ni 1-b-c Co b X c About 2-α D α (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.5,0<α<2);Li a Ni 1-b- c Mn b X c About 2-α D α (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.5,0<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≤0.5,0≤e≤0.1);Li a NiG b O2(0.90≤a≤1.8,0.001≤b≤0.1);Li a CoG b O2(0.90≤a≤1.8,0.001≤b≤0.1);Li a Mn 1-b G b O2(0.90≤a≤1.8,0.001≤b≤0.1);Li a Mn2G b O4(0.90≤a≤1.8,0.001≤b≤0.1);Li a Mn 1-g G g PO4 (0.90≤a≤1.8, 0≤g≤0.5);Li (3-f) Fe2(PO4)3(0≤f≤2);Li a FePO4 (0.90≤a≤1.8).

[0100] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, 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 L 1 is Mn, Al, or a combination thereof.

[0101] The positive electrode for a lithium secondary battery may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer includes a positive electrode active material and may further include a binder and / or a conductive material.

[0102] Based on 100% by weight of the positive electrode active material layer, the content of the positive electrode active material may be 90% to 99.5% by weight, and based on 100% by weight of the positive electrode active material layer, the contents of the binder and the conductive material may be 0.5% to 5% by weight, respectively.

[0103] As the current collector, Al can be used, but it is not limited thereto.

[0104] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0105] The material capable of reversibly intercalating / deintercalating the lithium ions may be a carbon-based negative electrode active material, which may include, for example, crystalline carbon, amorphous carbon, or a combination thereof. As an example of the crystalline carbon, graphite such as natural graphite or artificial graphite can be cited, and as an example of the amorphous carbon, soft carbon, hard carbon, mesophase pitch carbide, calcined coke, etc. can be cited.

[0106] A Si-based negative electrode active material or a Sn-based negative electrode active material can be used as the material capable of doping and dedoping lithium. The Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiO x (0 < x < 2), a Si-based alloy, or a combination thereof.

[0107] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one implementation example, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[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 on the surface of the core.

[0109] A negative electrode for a lithium secondary battery may include a current collector and a negative electrode active material layer located on the current collector. The negative electrode active material layer may include a negative electrode active material and may further include a binder and / or a conductive material.

[0110] For example, the negative active material layer may include 90 wt % to 99 wt % of the negative active material, 0.5 wt % to 5 wt % of the binder, and 0 wt % to 5 wt % of the conductive material.

[0111] The binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. When an aqueous binder is used as the negative electrode binder, a cellulose compound that can impart viscosity may also be included.

[0112] As the negative electrode current collector, a material selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof may be used.

[0113] The electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0114] The non-aqueous organic solvent functions as a medium that allows ions involved in the electrochemical reaction of the battery to move.

[0115] The non-aqueous organic solvent may be a carbonate, ester, ether, ketone, alcohol solvent, an aprotic solvent, or a combination thereof, and may be used alone or in combination of two or more.

[0116] When a carbonate-based solvent is used, a cyclic carbonate and a chain carbonate may be used in combination.

[0117] Depending on the type of lithium secondary battery, a separator may be present between the positive electrode and the negative electrode. As such a separator, polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more layers thereof may be used.

[0118] The separator may include a porous substrate and a coating layer comprising an organic substance, an inorganic substance, or a combination thereof, located on one surface or both surfaces of the porous substrate.

[0119] The organic matter may include a polyvinylidene fluoride-based polymer or a (meth)acrylic acid-based polymer.

[0120] The inorganic material may include inorganic particles selected from the group consisting of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof, but is not limited thereto.

[0121] The organic and inorganic substances may be mixed in one coating layer, or may be present in the form of a stack of a coating layer containing an organic substance and a coating layer containing an inorganic substance.

[0122] Figure 7 1 is a diagram illustrating an example of a secondary battery module in which secondary batteries are arranged according to an embodiment of the present invention. As the capacity of secondary batteries for driving electric vehicles increases, a secondary battery module can be manufactured by arranging and connecting a plurality of secondary battery cells horizontally and / or vertically.

[0123] A plurality of secondary batteries are arranged in a space formed by a pair of opposing end plates 71a, 71b and a pair of opposing side plates 72a, 72b. The arrangement direction and number of the secondary batteries can be designed in such a way as to obtain desired voltage and current specifications.

[0124] Figure 8 is included Figure 7 An exemplary diagram of a secondary battery pack of the illustrated secondary battery module.

[0125] The secondary battery pack 80 can be manufactured by embedding a plurality of secondary battery modules into a pack housing designed to be mounted on an actual product. The pack housing may include a fastening portion and an electrical lead-out portion required for mounting on a product. Figure 8 In the drawings, for convenience of illustration, illustration of related elements such as bus bars, cooling units, and external terminals for electrical connection of the secondary battery is omitted.

[0126] The secondary battery pack can be installed in a vehicle. As an example, the vehicle can be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle includes a four-wheel drive vehicle or a two-wheel drive vehicle.

[0127] Figure 9 is included Figure 8 A conceptual diagram of a vehicle illustrating an example of a secondary battery pack. Figure 9 A case is illustrated in which the secondary battery pack 80 according to an embodiment of the present invention is mounted on a lower portion of a vehicle body of a vehicle V. The vehicle V operates by receiving electric power from the secondary battery pack 80 according to an embodiment of the present invention.

[0128] Although the present invention has been described above with reference to the limited embodiments and drawings, the present invention is not limited thereto and it is obvious that various modifications and variations can be made by persons having ordinary knowledge in the technical field to which the present invention belongs within the scope equivalent to the technical idea of ​​the present invention and the scope of protection recorded in the claims.

[0129] Description of Reference Signs 40: electrode assembly; 41: first current collecting portion; 42: second current collecting portion; 43: first electrode terminal; 44: second electrode terminal (second uncoated portion); 51: housing; 60: cover assembly; 61: cover plate; 62: first terminal; 63: second terminal; 64: electrolyte injection port; 65: notch; 66: exhaust port; 67: terminal pin; 71a, 71b: end plate; 72a, 72b: side plate; 80: secondary battery pack; 1 00: Secondary battery; 110: Electrode assembly; 111: Electrode plate; 112: Diaphragm; 120: Housing; 130: Electrode tab; 140: Sub-plate; 150: Cover plate; 160: Sealing component; 161: Internal compression material; 162: External compression material; 163: Fastening component; 164: Adjustment component; 210: Terminal plate; 220: Rivet; 230: Current collector; 240: Sub-tab; 250: Lower insulating component.

Claims

1. A secondary battery comprising an electrode assembly and a housing for accommodating the electrode assembly, the secondary battery comprising: a plurality of electrode plates included in the electrode assembly; a plurality of electrode tabs extending from the plurality of electrode plates; a daughter board, coupled to the plurality of electrode tabs; a cover plate having a through hole formed therein, wherein a peripheral portion of the through hole is protruding, and the sub-plate passes through the through hole and is combined with the cover plate; and The sealing member is formed on the cover plate so as to surround the protruding peripheral portion of the through hole through which the sub-plate passes, and seals the joint between the cover plate and the sub-plate.

2. The secondary battery according to claim 1, wherein The sub-plate is combined with the plurality of electrode tabs by laser welding.

3. The secondary battery according to claim 1, wherein In the cover plate, The peripheral portion of the through hole through which the sub-plate passes is convex in a curved surface.

4. The secondary battery according to claim 1, wherein The sealing component includes: an internal compression material provided in a space between the sub-plate and the through-hole of the cover plate; External compression material, surrounding the periphery of the joint between the sub-plate and the cover plate; a fastening member surrounding the outer compressive material; and The adjusting component is provided on a portion of the fastening component to adjust the fastening degree of the fastening component.

5. The secondary battery according to claim 1, wherein The secondary battery is prismatic.

6. A method for manufacturing a secondary battery, characterized in that: The steps include: manufacturing an electrode assembly comprising a plurality of electrode plates; coupling a plurality of electrode tabs extending from the plurality of electrode plates to a sub-plate; The through hole of the cover plate is formed with a through hole and the peripheral portion of the through hole protrudes so that the sub-plate passes through and the sub-plate is coupled to the cover plate; a sealing member for the joint between the cover plate and the sub-plate in a manner of surrounding a protruding peripheral portion of the through hole through which the sub-plate passes; as well as The electrode assembly is housed in a case and the cap plate is combined with the case.

7. The secondary battery manufacturing method according to claim 6, characterized in that: The step of coupling the plurality of electrode tabs to the sub-plate comprises the following steps: bending the plurality of electrode tabs toward the sub-board so that the plurality of electrode tabs are in contact with the sub-board; and The plurality of electrode tabs and the sub-plate are combined by laser welding.

8. The method for manufacturing a secondary battery according to claim 6, wherein: The step of passing the sub-plate through the through hole and coupling the sub-plate to the cover plate comprises the following steps: The through-hole of the cover plate protrudes with a curved surface at a periphery of the through-hole, allowing the sub-plate to pass through, thereby coupling the sub-plate to the cover plate.

9. The method for manufacturing a secondary battery according to claim 6, wherein: The step of forming the sealing member so as to surround the protruding peripheral portion of the through hole through which the sub-board passes includes the following steps: providing an internal compression material in a space between the sub-plate and the through hole of the cover plate; Using external compression material to surround the periphery of the joint between the sub-plate and the cover plate; surrounding the outer compressive material with a fastening member; as well as An adjusting member for adjusting the degree of tightening of the tightening member is provided on a portion of the tightening member. 10 . A secondary battery module comprising a plurality of secondary batteries according to claim 1 arranged and connected in a horizontal or vertical direction.

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