Secondary battery and secondary battery module

Abstract

The utility model relates to a secondary battery and a secondary battery module. The technical problem to be solved is to provide a current path simplified structure which is used for solving the problems of cost increase and performance reduction caused by various components forming a current path of the secondary battery. Therefore, the utility model provides a secondary battery and a vehicle comprising the secondary battery, and the secondary battery comprises a plurality of electrode plates which are arranged in an 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 utility model relates to a secondary battery, and more particularly to a secondary battery in which a sub-board is used to replace a component constituting a current path of the secondary battery and is sealed with a sealing member. Background Art

[0002] Unlike a primary battery that cannot be charged, a secondary battery is a battery that can be charged and discharged. Low-capacity secondary batteries are used in portable small electronic devices such as smart phones, feature phones, notebook computers, digital cameras, and video cameras, and high-capacity secondary batteries are widely used as power sources for driving motors and power storage batteries for hybrid vehicles, electric vehicles, etc.

[0003] Generally, a secondary battery includes an electrode assembly formed by a positive electrode and a negative electrode, a case for 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 the technology that forms the background of the present utility model is only for enhancing the understanding of the background of the present utility model, and thus may also include information that does not constitute the prior art. Summary of the Utility Model

[0005] A secondary battery includes various components such as a terminal board, a rivet, a current collector, a lower insulating member, etc. that form a current path between the terminal portion and the electrode assembly. With the manufacturing and assembly of various components, the cost increases, and the current path passes through various components, resulting in an increase in resistance. Accordingly, there is a problem of deterioration in the performance of the secondary battery. Therefore, a simplified current path structure for reducing the cost and improving the performance of the secondary battery is proposed.

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

[0007] A secondary battery according to an embodiment of the present utility model for solving the above technical problems includes an electrode assembly and a case for accommodating the electrode assembly. The secondary battery may include: a plurality of electrode plates included in the electrode assembly; a plurality of electrode connection tabs extending from the plurality of electrode plates; a sub-board combined with the plurality of electrode connection tabs; a cover plate formed with a through hole, with a peripheral portion of the through hole protruding, the sub-board passing through the through hole and being combined with the cover plate; and a sealing member formed on the cover plate to surround the protruding peripheral portion of the through hole through which the sub-board passes and sealing the combined portion of the cover plate and the sub-board.

[0008] The sub-board may be combined with the plurality of electrode connection tabs by laser welding.

[0009] In the cover plate, the peripheral portion of the through hole penetrated by the sub-plate may protrude in a curved surface.

[0010] The sealing member may include: an internal compression material disposed in a space between the through hole of the sub-plate and the cover plate; an external compression material surrounding the periphery of the joint portion of the sub-plate and the cover plate; a fastening member surrounding the external compression material; and an adjusting member disposed in a part of the fastening member to adjust the fastening degree of the fastening member.

[0011] The secondary battery may be prismatic.

[0012] According to another aspect of the present invention, there may be provided a secondary battery module in which a plurality of the above-described secondary batteries are arranged and connected in a lateral or longitudinal direction.

[0013] According to still another aspect of the present invention, there may be provided a vehicle including a secondary battery pack manufactured using the secondary battery having the above-described configuration.

[0014] According to an embodiment of the present invention, a sub-plate is used instead of a component constituting a current path of a secondary battery, whereby there is an effect of reducing the cost of the secondary battery as the number of components is reduced and improving the performance by reducing the resistance path length.

[0015] In particular, by removing components such as a terminal plate, a rivet, a current collector, a lower insulating member, etc. that constitute a current path between a terminal portion and an electrode assembly, and removing an assembly process such as welding or riveting, the production cost of the secondary battery can be reduced.

[0016] Moreover, the contact resistance between components decreases as the number of components decreases, and the component resistance decreases as the current path is shortened, thereby having an effect of improving the performance of the secondary battery.

[0017] In addition, in a vehicle applying the secondary battery of the present invention, it is possible to reduce the cost of the secondary battery that accounts for the largest proportion in the vehicle price and improve the performance, thereby being able to improve the performance such as driving performance and driving distance while reducing the vehicle price.

[0018] However, the effects that can be obtained by the present invention are not limited to the above effects, and those skilled in the art can clearly understand other technical effects not mentioned from the description of the present invention described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following drawings attached to this specification illustrate preferred embodiments of the present invention and are used to further understand the technical idea of the present invention in combination with the detailed description of the present invention described later. Therefore, the present invention should not be construed as being limited to the matters described in the drawings.

[0020] Figure 1a is a top perspective view of a conventional prismatic secondary battery.

[0021] Figure 1b is Figure 1a a sectional view taken along line I-I′.

[0022] Figure 2a is a side sectional view of a secondary battery according to an embodiment of the present utility model.

[0023] Figure 2b is a plan view of a secondary battery according to an embodiment of the present utility model.

[0024] Figure 2c is a top front view of a secondary battery according to an embodiment of the present utility model.

[0025] Figure 3a is a side sectional view of a sealing member of a secondary battery according to an embodiment of the present utility model.

[0026] Figure 3b is a view showing a first embodiment of a sealing member of a secondary battery according to an embodiment of the present utility model.

[0027] Figure 3c is a view showing a second embodiment of a sealing member of a secondary battery according to an embodiment of the present utility model.

[0028] Figure 3d is a view showing a third embodiment of a sealing member of a secondary battery according to an embodiment of the present utility model.

[0029] Figure 4a is a view showing a current path of a conventional prismatic secondary battery.

[0030] Figure 4b is a plan view showing a terminal portion of a conventional prismatic secondary battery.

[0031] Figure 4c is a front view showing a terminal portion of a conventional prismatic secondary battery.

[0032] Figure 5a is a view showing a current path of a secondary battery according to an embodiment of the present utility model.

[0033] Figure 5b is a plan view of a terminal portion of a secondary battery according to an embodiment of the present utility model.

[0034] Figure 5c is a front view of a terminal portion of a secondary battery according to an embodiment of the present utility model.

[0035] Figures 6a to 6f It is a diagram for explaining a method of manufacturing a secondary battery according to an embodiment of the present utility model.

[0036] Figure 7 It is an exemplary diagram of a secondary battery module arranging secondary batteries according to an embodiment of the present utility model.

[0037] Figure 8 It includes Figure 7 An exemplary diagram of a secondary battery pack including the illustrated secondary battery module.

[0038] Figure 9 It includes Figure 8 A conceptual diagram of a vehicle including the illustrated secondary battery pack. Detailed Description of the Preferred Embodiment

[0039] Hereinafter, preferred embodiments of the present utility model will be described in detail with reference to the accompanying drawings. Before the description, terms or words used in this specification and claims should not be construed as limited to general or dictionary meanings, but should be interpreted as meanings and concepts conforming to the technical idea of the present utility model based on the principle that the inventor may appropriately define the concept of terms in order to best explain his own utility model. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred partial embodiments of the present utility model and do not represent all the technical ideas of the present utility model. Therefore, it should be understood that there may be various equivalents and modification examples that can replace these at the time of this application.

[0040] Also, when used in this specification, "comprise, include" and / or "comprising, including" are used for the presence of specific mentioned shapes, numbers, steps, operations, components, elements and / or combinations thereof, and do not exclude the presence or addition of one or more other shapes, numbers, operations, components, elements and / or combinations thereof.

[0041] In addition, to assist in understanding the utility model, the drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. In addition, the same reference numerals may be given to the same components in different embodiments.

[0042] Referring to two comparison objects as "the same" means "substantially the same". Therefore, substantially the same may include cases having deviations considered to be at a relatively low level in the art. For example, it may include cases having a deviation within 5%. In addition, certain parameters being uniform in a predetermined area may mean being uniform from an average point of view.

[0043] Although the first, second, etc. are used to illustrate various components, these components are clearly not limited by these terms. These terms are only used to distinguish one component from other components. Obviously, the first component can also be the second component as long as there is no special contrary record.

[0044] Throughout the specification, unless there is a special contrary record, each component can be singular or plural.

[0045] Arranging any component “above (or below)” a component or “on (or under)” a component not only means that the any component is arranged in contact with the upper (or lower) surface of the said component, but also means that other components can be interposed between the said component and the any component arranged on (or under) the said component.

[0046] And when it is described that a certain component is “on”, “connected to” or “coupled to” another component, the components can be directly connected or coupled to each other, but it should be understood that another component can also be “interposed” between the components, or the components can also be “connected”, “coupled” or “joined” through another component.

[0047] As used in this specification, the term “and / or” includes any combination or all combinations of one or more of the associated listed items. In addition, “may” used when describing embodiments of the present invention is with respect to “one or more embodiments of the present invention”. “One or more” before a list of elements and expressions such as “one or more” modify the entire list of elements, not individual elements in the list.

[0048] Throughout the specification, when referring to “A and / or B”, unless there is a special contrary record, it means A, B or A and B; when referring to “C to D”, unless there is a special contrary record, it means C or more and D or less.

[0049] 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 consisting of A, B and C” or “at least one selected from A, B and C” are used to specify a list of A, B and C, the statements can refer to any all suitable combinations.

[0050] The term "use" may be regarded as synonymous with the term "utilize". As used in this specification, the terms "substantially", "about" and similar terms are used as approximate terms rather than terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by a person of ordinary skill in the art.

[0051] 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. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer or part discussed below may be referred to as the second element, component, region, layer or part.

[0052] To describe the relationship of one element or feature shown in the figure to another element or feature, for the convenience of description, spatial relative terms such as "beneath", "below", "lower", "above", "upper", etc. may be used in the specification. It should be understood that the spatial relative positions include not only the directions depicted in the figure but also different directions of the device in use or operation. For example, if the device in the figure is flipped, other elements are understood to be "beneath" or "below" other elements, and the illustrated elements are understood to be "above" or "upper" other elements. Thus, the term "below" can cover both the upward and downward directions.

[0053] 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.

[0054] The types of secondary batteries include coin type, cylindrical type, prismatic type and pouch type. Since the present invention can basically be applied to prismatic secondary batteries, before describing the embodiments of the present invention, a schematic description of the prismatic secondary battery is first given.

[0055] Figure 1a is a perspective view of the upper part of a conventional prismatic secondary battery, Figure 1b is Figure 1a the cross-sectional view taken along line I-I′ of

[0056] First, the appearance of the conventional prismatic secondary battery shown in Figure 1a is described.

[0057] The housing 51 forms the overall appearance of the prismatic secondary battery and can be formed of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. In addition, the housing 51 can provide a space for accommodating the electrode assembly.

[0058] The cap assembly 60 may include a cover plate 61 that covers the opening of the housing 51, and the housing 51 and the cover plate 61 may be formed of a conductive material. Here, the first terminal 62 and the second terminal 63 may be provided to be electrically connected to the internal positive electrode or negative electrode and protrude outward through the cover plate 61.

[0059] An electrolyte injection port 64 where a sealing plug can be provided may be formed in the cover plate 61, and an exhaust port 66 having a notch 65 may be provided. The exhaust port 66 is used for degassing the gas generated inside the battery.

[0060] Refer to Figure 1b for an explanation of the internal structure of the prismatic secondary battery and the coupling structure with the cap assembly 60.

[0061] Figure 1b The prismatic secondary battery shown may basically include an electrode assembly 40, a first current collector 41, a first terminal 62, a second current collector 42, a second terminal 63, and a cap assembly 60.

[0062] 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 that are formed in 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 housing 51. In addition, the electrode assembly 40 can be a stacked type instead of a wound type, but in the present utility model, the shape of the electrode assembly 40 is not limited. In addition, the electrode assembly 40 can be a Z-stack electrode assembly in which the first electrode plate and the second electrode plate are inserted on both sides of a separator bent into a Z-stack. In addition, the electrode assembly 40 can be a stack in which the long sides of one or more electrode assemblies are adjacent to each other and accommodated inside the housing, and in the present utility model, the number of electrode assemblies is not limited. The first electrode plate of the electrode assembly 40 can function as a negative electrode, and the second electrode plate can function as a positive electrode, and vice versa.

[0063] The first electrode plate can be formed by coating a first electrode current collector plate made of 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) that is an area where the first electrode active material is not coated. The first electrode tab 43 can serve as a channel 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 portion and can protrude further toward one side portion than the separator without separate cutting.

[0064] The second electrode plate can be formed by coating a substrate made of a metal foil such as aluminum or aluminum alloy with a second electrode active material such as a transition metal oxide, and can include a second electrode tab (or second uncoated portion) 44 that is an area where the second electrode active material is not coated. The second electrode tab 44 can serve as a channel 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 portion and can protrude further toward the other side portion than the separator without separate cutting.

[0065] In some embodiments, the first electrode tab 43 can be located on the right end side surface of the electrode assembly 40, and the second electrode tab 44 can be located on the left end side surface of the electrode assembly 40, or can also be located on one surface in the same direction. Here, the left and right sides are based on the secondary battery shown in FIG. 1 for ease of explanation, and their positions can change when the secondary battery is rotated left and right or up and down.

[0066] The separator functions to allow the movement of lithium ions while preventing short circuits between the first electrode plate and the second electrode plate. The separator can be made of, for example, a polyethylene film, a polypropylene film, a polyethylene - polypropylene film, etc.

[0067] 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 as described above. In some embodiments, the electrode assembly 40 can be accommodated in a housing 51 together with an electrolyte.

[0068] In the electrode assembly 40, the first electrode tab 43 and the second electrode tab 44 extending to both sides from the first electrode plate and the second electrode plate are respectively connected to the first current collecting portion 41 and the second current collecting portion 42 by welding.

[0069] The first current collecting portion 41 and the second current collecting portion 42 are respectively connected to Figure 2aIt is connected to the first terminal 62 and the second terminal 63 described in []. In some embodiments, the outer peripheral surface of the terminal pin 67 can be threaded and can be fastened to the first terminal 62 and the second terminal 63 by screw engagement. However, the present invention is not limited thereto, and the terminal pin 67 can also be combined with the first terminal 62 and the second terminal 63 by riveting or welding.

[0070] A secondary battery according to an embodiment of the present invention is proposed to have a structure different from that of the conventional prismatic secondary battery shown in Figure 1a and Figure 1b The structure of the secondary battery according to an embodiment of the present invention will be described below with reference to Figures 2a to 2c to describe the structure of the secondary battery according to an embodiment of the present invention.

[0071] Figure 2a FIG. is a side cross-sectional view of a secondary battery according to an embodiment of the present invention, Figure 2b FIG. is a plan view of a secondary battery according to an embodiment of the present invention, Figure 2c FIG. is a front top view of a secondary battery according to an embodiment of the present invention.

[0072] Referring to Figures 2a to 2c , a secondary battery 100 according to an embodiment of the present invention includes: an electrode assembly 110, a housing 120 for accommodating the electrode assembly 110, a plurality of electrode connection tabs 130, a daughter board 140; a cover plate 150 and a sealing member 160.

[0073] The electrode assembly 110 includes a plurality of electrode plates 111 and a separator 112, and can be formed by winding or stacking a stack of a plurality of electrode plates 111 and a separator 112 formed in a plate shape or a film shape. When the electrode assembly 110 is a wound stack, the winding axis can be parallel to the length direction of the housing. In addition, the electrode assembly 110 can be a stacked type instead of 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 housing 120 together with the electrolyte.

[0074] The plurality of electrode plates 111 can have a positive or negative polarity according to the polarity of the corresponding terminal. In addition, the plurality of electrode plates 111 can include a coated portion coated with an active material and an uncoated portion not coated with an active material. When the plurality of electrode plates 111 are negative electrodes, the plurality of electrode plates 111 can be formed by coating an active material such as graphite or carbon on a metal foil such as copper, copper alloy, nickel or nickel alloy. When the plurality of electrode plates 111 are positive electrodes, the plurality of electrode plates 111 can be formed by coating an active material such as a transition metal oxide on a metal foil such as aluminum or aluminum alloy.

[0075] The separator 112 functions to allow the movement of lithium ions while preventing short circuits between the multiple electrode plates 111. The separator 112 can be made of, for example, a polyethylene film, a polypropylene film, a polyethylene - polypropylene film, etc.

[0076] The case 120 forms the overall appearance of the prismatic secondary battery and can be made of a conductive metal such as aluminum, an aluminum alloy, or nickel - plated steel. In addition, the case 120 provides a space for accommodating the electrode assembly 110.

[0077] Multiple electrode tabs 130 extend from the multiple electrode plates 111. In one embodiment, the multiple electrode tabs 130 can extend from the uncoated portions of the multiple electrode plates 111.

[0078] The multiple electrode tabs 130 are coupled to the sub - plate 140. The sub - plate 140 functions to collect the current transmitted from the electrode assembly 110 through the multiple electrode tabs 130 and transmit it to the outside. In one embodiment, the sub - plate 140 can be made of the same material as the multiple electrode plates 111 and the multiple electrode tabs 130. And, in one embodiment, the sub - plate 140 can be coupled to the multiple electrode tabs 130 by laser welding.

[0079] The cover plate 150 is coupled to the sub - plate 140 by passing the sub - plate 140 through the cover plate 150. The cover plate 150 can be formed with a through - hole for passing the sub - plate 140, and the peripheral portion forming the through - hole can protrude. In one embodiment, the peripheral portion of the through - hole of the cover plate 150 through which the sub - plate 140 passes can protrude in a curved surface. Since the peripheral portion of the through - hole of the cover plate 150 protrudes in a curved surface, the sealing member 160 described later can effectively seal the joint portion between the cover plate 150 and the sub - plate 140. The cover plate 150 has a generally rectangular plate shape. The cover plate 150 covers the opening of the case 120. For example, the cover plate 150 can be coupled to the case 120 by methods such as laser welding. Similar to the case 120, the cover plate 150 can be made of a conductive material.

[0080] The sealing member 160 is formed to surround the protruding peripheral portion of the through - hole through which the sub - plate 140 passes on the cover plate 150 and seals the joint portion between the cover plate 150 and the sub - plate 140. The sealing member 160 is used to prevent liquids such as the electrolyte inside the secondary battery or gases generated due to internal chemical reactions from leaking to the outside of the secondary battery.

[0081] Hereinafter, with reference to Figures 3a to 3d , the structure, function, and embodiments of the sealing member 160 will be described.

[0082] Figure 3a is a side cross - sectional view of the sealing member of the secondary battery according to an embodiment of the present utility model, Figure 3bFIG. 0 is a view showing a first embodiment of a sealing member of a secondary battery according to an embodiment of the present invention. Figure 3c FIG. 1 is a view showing a second embodiment of a sealing member of a secondary battery according to an embodiment of the present invention. Figure 3d FIG. 2 is a view showing a third embodiment of a sealing member of a secondary battery according to an embodiment of the present invention.

[0083] Referring to Figure 3a , the sealing member 160 of the secondary battery 100 according to an embodiment of the present invention may include an internal compression material 161, an external compression material 162, and a fastening member 163.

[0084] The internal compression material 161 is disposed in a space between the through holes of the sub-board 140 and the cover board 150. The external compression material 162 surrounds the periphery of the joint portion of the sub-board 140 and the cover board 150, and the fastening member 163 surrounds the external compression material 162. The internal compression material 161 and the external compression material 162 are made of a polymer compression material such as rubber or silicone resin. The fastening member 163 surrounds the outside, thereby ensuring a sealing force.

[0085] Referring to 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 disposed on a part of the fastening member 163 to adjust the fastening degree of the fastening member 163. The adjusting member 164 can ensure the sealing force of the sealing member 160 by clamping the fastening member 163.

[0086] In addition, in addition to performing a sealing function, the sealing member 160 can also perform an exhaust port function of relieving the seal and discharging gas when a predetermined internal pressure increases. At this time, the adjusting member 164 controls the fastening degree of the fastening member 163 at a predetermined level, thereby being able to adjust the breaking pressure at which the seal is released.

[0087] As Figure 3b shown, the adjusting member 164 may be a clamp formed on one side. As Figure 3c shown, the adjusting members 164-1 and 164-2 may be clamps formed on both sides. In this case of the clamping method, the sealing force and the breaking force can be controlled by adjusting the torque of the tightening screw.

[0088] As Figure 3d shown, the adjusting member 164 may be a cable tie. In this case of the cable tie method, the fastening force, the sealing force, and the breaking pressure can be controlled by adjusting the tension.

[0089] Above, the structure of the secondary battery according to an embodiment of the present invention has been described. Hereinafter, referring to Figures 4a to 5cThe advantageous effects resulting from the structural differences between a secondary battery according to an embodiment of the present utility model and a conventional prismatic secondary battery will be described.

[0090] Figure 4a FIG. 4 is a diagram showing the current path of a conventional prismatic secondary battery. Figure 4b FIG. 5 is a plan view showing the terminal portion of a conventional prismatic secondary battery. Figure 4c FIG. 6 is a front view showing the terminal portion of a conventional prismatic secondary battery.

[0091] Referring to Figures 4a to 4c , the current path of a conventional prismatic secondary battery includes a terminal plate 210, a rivet 220, a current collector 230, a sub-tab 240, and a lower insulating member 250. In a conventional prismatic secondary battery, in the case of the negative terminal, the movement path of electrons is transmitted from the electrode assembly via the sub-tab 240, the current collector 230, the rivet 220, and the terminal plate 210 to the outside. Thus, since the current path of a conventional prismatic secondary battery passes through various components, contact resistance is generated between the components, and the current path becomes longer, increasing the component resistance, thereby affecting the performance of the secondary battery. In addition, as various components are used, the cost of the secondary battery also increases.

[0092] Figure 5a FIG. 7 is a diagram showing the current path of a secondary battery according to an embodiment of the present utility model. Figure 5b FIG. 8 is a plan view of the terminal portion of a secondary battery according to an embodiment of the present utility model. Figure 5c FIG. 9 is a front view of the terminal portion of a secondary battery according to an embodiment of the present utility model.

[0093] Referring to Figures 5a to 5c , the current path of a secondary battery according to an embodiment of the present utility model consists only of a plurality of electrode tabs 130 and a sub-board 140. In a secondary battery according to an embodiment of the present utility model, in the case of the negative terminal, the movement path of electrons is directly transmitted from the electrode assembly 110 to the outside through the plurality of electrode tabs 130 and the sub-board 140. Thus, in the current path of a secondary battery according to an embodiment of the present utility model, all components such as the terminal plate, rivet, current collector, and lower insulating member 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 decreases, 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 constituting the current path and removing assembly processes such as welding or riveting, the production cost of the secondary battery can be reduced.

[0094] Figures 6a to 6f FIG. 10 is a diagram for explaining a method of manufacturing a secondary battery according to an embodiment of the present utility model.

[0095] Refer to Figure 6a , and manufacture an electrode assembly 110 including a plurality of electrode plates 111. At this time, a plurality of electrode connection tabs 130 may be provided to extend from the plurality of electrode plates 111.

[0096] Refer to Figure 6b and Figure 6c , and bond a plurality of electrode connection tabs 130 extending from the plurality of electrode plates 111 to the daughter board 140. In Figure 6b embodiments, the plurality of electrode connection tabs 130 may be bent toward the daughter board 140 so that the plurality of electrode connection tabs 130 come into contact with the daughter board 140. Moreover, in Figure 6c embodiments, the plurality of electrode connection tabs 130 and the daughter board 140 may be bonded by laser welding.

[0097] Refer to Figure 6d , and pass the daughter board 140 through a through-hole of a cover plate 150 in which the through-hole is formed and the peripheral portion of the through-hole protrudes, and bond it to the cover plate 150. In Figure 6d embodiments, the daughter board 140 may be passed through a through-hole of the cover plate 150 in which the peripheral portion of the through-hole protrudes in a curved surface, and bonded to the cover plate 150.

[0098] Refer to Figure 6e , and a sealing member 160 for the joint portion of the cover plate 150 and the daughter board 140 is formed to surround the protruding peripheral portion of the through-hole through which the daughter board 140 passes. In Figure 6e embodiments, an internal compression material 161 is provided in the space between the through-hole of the daughter board 140 and the cover plate 150, and the peripheral portion of the joint portion of the daughter board 140 and the cover plate 150 is surrounded by an external compression material 162. Moreover, the external compression material 162 may be surrounded by a fastening member 163, and an adjusting member 164 for adjusting the fastening degree of the fastening member 163 may be provided on a part of the fastening member 163.

[0099] Refer to Figure 6f , and accommodate the electrode assembly 110 in the housing 120, and bond the cover plate 150 and the housing 120. In Figure 6f embodiments, the cover plate 150 and the housing 120 may be bonded by welding.

[0100] Hereinafter, materials that can be used for the secondary battery according to the present utility model will be described.

[0101] As the positive electrode active material, a compound capable of reversibly inserting and extracting lithium (lithiated insertion compound) may be used. Specifically, one or more of composite oxides of metals selected from cobalt, manganese, nickel, and combinations thereof with lithium may be used.

[0102] The composite oxide may be a lithium transition metal composite oxide. As specific examples, 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 can be cited.

[0103] As an example, a compound 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, 0 ≤ c ≤ 0.05); Li a Mn 2-b X b O 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 O 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 O 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); LiaMn1-bGbO2 (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 gPO4 (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).

[0104] 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.

[0105] 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 contain a binder and / or a conductive material.

[0106] 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.

[0107] As the current collector, Al may be used, but is not limited thereto.

[0108] The negative electrode active material includes a material capable of reversibly inserting / extracting lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and undoping lithium, or a transition metal oxide.

[0109] The material capable of reversibly inserting / extracting 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 may be cited, and as an example of the amorphous carbon, soft carbon, hard carbon, mesophase pitch carbide, calcined coke, etc. may be cited.

[0110] As the material capable of doping and undoping lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. 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.

[0111] 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.

[0112] 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 located on the surface of the core.

[0113] The 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 contain a binder and / or a conductive material.

[0114] For example, the negative electrode active material layer may include 90% to 99% by weight of the negative electrode active material, 0.5% to 5% by weight of the binder, and 0% to 5% by weight of the conductive material.

[0115] A non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof may be used as the binder. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may also be included.

[0116] 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 combinations thereof may be used.

[0117] The electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0118] The non-aqueous organic solvent serves as a medium that allows ions participating in the electrochemical reaction of the battery to move.

[0119] The non-aqueous organic solvent may be a carbonate, an ester, an ether, a ketone, an alcohol solvent, an aprotic solvent, or a combination thereof, and may be used alone or in combination of two or more.

[0120] In addition, when a carbonate solvent is used, a cyclic carbonate and a chain carbonate may be mixed and used.

[0121] 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 of them may be used.

[0122] The separator may include a porous substrate and a coating containing an organic substance, an inorganic substance, or a combination thereof located on one surface or both surfaces of the porous substrate.

[0123] The organic substance may include a polyvinylidene fluoride-based polymer or a (meth)acrylic acid-based polymer.

[0124] The inorganic substance may include 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, but is not limited thereto.

[0125] The organic substance and the inorganic substance may be present by being mixed in one coating, or may be present in a form in which a coating containing the organic substance and a coating containing the inorganic substance are stacked.

[0126] Figure 7 FIG. is an exemplary view of a secondary battery module in which secondary batteries are arranged according to an embodiment of the present invention. As the secondary batteries for driving an electric vehicle have increased in capacity, a secondary battery module can be manufactured by arranging and connecting a plurality of secondary battery cells horizontally and / or vertically.

[0127] 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 of the secondary batteries can be designed in terms of the arrangement direction and the number in such a way as to obtain desired voltage and current specifications.

[0128] Figure 8 includes Figure 7 An exemplary view of a secondary battery pack including the illustrated secondary battery module.

[0129] The secondary battery pack 80 can be manufactured by incorporating a plurality of secondary battery modules into a group housing designed in a form to be mounted on an actual product. The group housing may include fastening portions and electrical lead-out portions required for mounting to the product. In Figure 8 , for ease of illustration, illustrations of related components such as bus bars, cooling units, and external terminals for electrical connection of the secondary batteries are omitted.

[0130] The secondary battery pack can be mounted in a vehicle. As an example, the vehicle may be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle includes a four-wheel drive or two-wheel drive vehicle.

[0131] Figure 9 includes Figure 8 A conceptual view of a vehicle including the illustrated secondary battery pack. Figure 9 Illustrates a case where the secondary battery pack 80 according to an embodiment of the present invention is mounted under the body of a vehicle V. The vehicle V operates by receiving power from the secondary battery pack 80 according to an embodiment of the present invention.

[0132] As mentioned above, although the present utility model has been described by way of limited embodiments and drawings, the present utility model is not limited thereto. Obviously, various modifications and variations can be made by those with ordinary knowledge in the technical field to which the present utility model belongs within the equivalent scope of the technical idea of the present utility model and the protection scope recorded in the claims.

[0133] Description of Reference Numerals

[0134] 40: Electrode assembly; 41: First current collector part; 42: Second current collector part; 43: First electrode connection tab; 44: Second electrode connection tab (second uncoated part); 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 plates; 72a, 72b: Side plates; 80: Secondary battery pack; 100: Secondary battery; 110: Electrode assembly; 111: Electrode plate; 112: Separator; 120: Housing; 130: Electrode connection tab; 140: Daughter board; 150: Cover plate; 160: Sealing member; 161: Internal compression material; 162: External compression material; 163: Fastening member; 164: Adjusting member; 210: Terminal board; 220: Rivet; 230: Current collector; 240: Daughter connection tab; 250: Lower insulating member.

Claims

1. A secondary battery, comprising an electrode assembly and a housing for accommodating the electrode assembly, characterized in that, The secondary battery includes: a plurality of electrode plates included in the electrode assembly; a plurality of electrode tabs extending from the plurality of electrode plates; a sub-board coupled to the plurality of electrode tabs; a cover plate formed with a through-hole, a peripheral portion of the through-hole being convex, and the sub-board passing through the through-hole to be coupled to the cover plate; and a sealing member formed on the cover plate so as to surround the convex peripheral portion of the through-hole through which the sub-board passes, and sealing a coupling portion between the cover plate and the sub-board.

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

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

4. The secondary battery according to claim 1, wherein the sealing member includes: an internal compression material disposed in a space between the sub-board and the through-hole of the cover plate; an external compression material surrounding a periphery of a coupling portion between the sub-board and the cover plate; a fastening member surrounding the external compression material; and an adjusting member disposed in a part of the fastening member to adjust a fastening degree of the fastening member.

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

6. A secondary battery module, characterized in that, A plurality of secondary batteries according to claim 1 are arranged and connected in a lateral or longitudinal direction.

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