Cap assembly, secondary battery, and method for manufacturing secondary battery

Abstract

Disclosed are a cap assembly, a secondary battery, and a method for manufacturing the secondary battery. A cap assembly includes: a terminal portion to be electrically connected to an electrode plate of an electrode assembly; a laser-transmitting glass part disposed above a region where a current collecting member electrically connecting the electrode plate of the electrode assembly and the terminal part is joined to the electrode assembly; and a cover plate which has a terminal opening coupled to the terminal part and a glass opening coupled to the glass part, and which is coupled to a case that accommodates the electrode assembly.

Description

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2024-0124338, filed on September 11, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] Embodiments of this disclosure relate to a cover assembly, a secondary battery, and a method for manufacturing a secondary battery. Background Technology

[0003] Unlike primary batteries, which are not designed to be (re)charged, secondary batteries are designed to be discharged and recharged. Low-capacity secondary batteries are used in portable small electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources to drive motors in vehicles such as hybrid or electric vehicles and for energy storage.

[0004] Typically, a secondary battery includes an electrode assembly (comprising a positive electrode and a negative electrode (or composed of a positive electrode and a negative electrode)), a housing that houses the electrode assembly, terminals that connect to the electrode assembly, and various components that connect the terminals and the electrode assembly. These components are joined in a manner that is prone to poor connection due to movement or unevenness between components, differences in component positions, or gaps between welded surfaces.

[0005] The information disclosed in this background section is intended to enhance the understanding of the background art of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0006] Embodiments of this disclosure relate to a cover assembly including a glass capable of transmitting laser light, a secondary battery including the cover assembly, and a method for manufacturing the secondary battery.

[0007] However, the aspects and features of this disclosure are not limited to those discussed above, and those skilled in the art will clearly understand other aspects and features not mentioned herein through the following description of this disclosure.

[0008] According to an embodiment of the present disclosure, a cover assembly includes: a terminal portion electrically connected to an electrode plate of an electrode assembly; a laser-transmitting glass portion disposed above the area where a current collector of the electrode plate electrically connected to the electrode assembly and the terminal portion is coupled to the electrode assembly; and a cover plate having a terminal opening coupled to the terminal portion and a glass opening coupled to the glass portion, and coupled to a housing accommodating the electrode assembly.

[0009] In one embodiment, the terminal portion may have a welding groove to be engaged with a protrusion or recess formed in the current collector.

[0010] In an embodiment, the cover plate may include: an upper cover plate having an upper glass opening at the portion where it is joined with the glass portion; and a lower cover plate having a mounting groove and a lower glass opening at the portion where it is joined with the glass portion, wherein the glass portion is disposed.

[0011] In an embodiment, the cover assembly may further include gaskets disposed at the points where the upper cover plate and the glass portion contact each other, and at the points where the lower cover plate and the glass portion contact each other.

[0012] In one embodiment, the upper cover plate and the lower cover plate of the cover plate can be joined together by welding at the area where the upper cover plate and the lower cover plate contact each other.

[0013] In one embodiment, the cover assembly may further include an upper insulating portion between the terminal portion and the cover plate.

[0014] In one embodiment, the cover assembly may further include an insulating plate between the cover plate and the current collector.

[0015] According to one embodiment of this disclosure, a secondary battery includes: an electrode assembly; a housing for accommodating the electrode assembly; a cover assembly coupled to the housing; and a current collector electrically connected to an electrode plate of the electrode assembly and a terminal portion of the cover assembly. The cover assembly includes: a terminal portion electrically connected to the electrode plate of the electrode assembly; a laser-transmitting glass portion disposed above the area where the current collector and the electrode assembly are coupled; and a cover plate having a terminal opening coupled to the terminal portion and a glass opening coupled to the glass portion.

[0016] In one embodiment, the electrode assembly and the current collector can be welded using a laser passing through the glass section.

[0017] In an embodiment, the current collector may have protrusions and recesses for engaging with the terminal portion.

[0018] In one embodiment, the terminal portion may have a welding groove for engaging with the protrusions and recesses of the current collector.

[0019] In an embodiment, the cover plate may include: an upper cover plate having an upper glass opening at the portion where it is joined with the glass portion; and a lower cover plate having a mounting groove and a lower glass opening at the portion where the glass portion is joined with the glass portion.

[0020] In an embodiment, the cover assembly may further include gaskets disposed at the points where the upper cover plate and the glass portion contact each other, and at the points where the lower cover plate and the glass portion contact each other.

[0021] In one embodiment, the upper cover plate and the lower cover plate of the cover plate can be joined together by welding at the point where the upper cover plate and the lower cover plate contact each other.

[0022] In one embodiment, the cover assembly may further include an upper insulating portion between the terminal portion and the cover plate.

[0023] In one embodiment, the cover assembly may further include an insulating plate between the cover plate and the current collector.

[0024] According to one embodiment of this disclosure, a method for manufacturing a secondary battery includes: manufacturing a cover assembly, the cover assembly being coupled to a housing housing an electrode assembly; coupling the cover assembly and the current collector by coupling a current collector and a terminal portion of the cover assembly; electrically connecting an electrode plate of the electrode assembly and the terminal portion of the cover assembly by coupling the current collector and the electrode assembly; housing the electrode assembly in the housing; and coupling the cover assembly and the housing. Manufacturing the cover assembly includes: manufacturing a cover plate having a terminal opening coupled to the terminal portion and a glass opening coupled to a laser-transmitting glass portion, and coupling it to the housing; coupling the terminal portion of the electrode plate electrically connected to the electrode assembly to the terminal opening; and coupling the glass portion disposed above the area where the current collector and the electrode assembly are coupled to the glass opening.

[0025] In an embodiment, the terminal portion of the electrode plate electrically connecting the electrode assembly and the cover assembly may include combining the electrode assembly and the current collector by laser welding through the glass portion.

[0026] In an embodiment, combining the cover assembly and the current collection member may include welding the protrusions and recesses in the current collection member and the terminal portion through a welding groove in the terminal portion.

[0027] In an embodiment, joining the glass portion to the glass opening may include: placing the glass portion in a mounting groove in the lower cover plate of the cover plate; placing the upper cover plate above the lower cover plate; and joining the upper cover plate and the lower cover plate by welding the areas where the upper cover plate and the lower cover plate contact each other.

[0028] According to embodiments of this disclosure, product reliability and mass production efficiency can be improved by reducing or minimizing the risk of poor adhesion between the current collector and the cover assembly, since the current collector and the electrode assembly are joined by irradiating the glass portion of the cover assembly with a laser after the cover assembly and the current collector, which includes a laser-transmitting glass portion, have been joined.

[0029] However, the aspects and features of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the following description of this disclosure other aspects and features not specifically mentioned herein. Attached Figure Description

[0030] The accompanying drawings illustrate embodiments of this disclosure and, together with the foregoing description, provide a further understanding of the technical spirit of this disclosure. Therefore, this disclosure should not be construed as limited to the contents described in the drawings, wherein:

[0031] Figure 1A This is a top perspective view of a prismatic secondary battery based on existing technology.

[0032] Figure 1B It is along Figure 1A The cross-sectional view taken from line I-I' in the diagram.

[0033] Figure 2A This is a perspective view of a secondary battery with side terminals based on existing technology.

[0034] Figure 2B yes Figure 2A The diagram shows a cross-sectional view of the terminal portion of the secondary battery with side terminals.

[0035] Figure 2C yes Figure 2A An exploded perspective view of the terminal portion of the secondary battery shown.

[0036] Figure 2D yes Figure 2A The diagram shows an exploded cross-sectional view of the terminal portion of the secondary battery with side terminals.

[0037] Figure 3A This is a schematic diagram illustrating a cover assembly according to an embodiment of the present disclosure.

[0038] Figure 3B This is a cross-sectional view of the glass incorporated into the cover assembly according to an embodiment of the present disclosure.

[0039] Figure 4A This is a perspective view illustrating the combined cover assembly and flow collector according to an embodiment of the present disclosure.

[0040] Figure 4B This is a side view illustrating the combined cover assembly and flow collector according to an embodiment of the present disclosure.

[0041] Figure 5A This is a perspective view illustrating the electrode assembly and current collector after the cover assembly and current collector have been combined, according to an embodiment of the present disclosure.

[0042] Figure 5B This is a side view illustrating the electrode assembly and current collector after the cover assembly and current collector have been combined, according to an embodiment of the present disclosure.

[0043] Figure 6 This is a perspective view illustrating the assembly of the cover assembly and the housing after the cover assembly, current collector and electrode assembly have been assembled, according to an embodiment of the present disclosure.

[0044] Description of some figure labels

[0045] 110: Cover assembly; 111: Terminal section

[0046] 112: Glass 113: Cover plate

[0047] 113-1: Upper cover plate; 113-2: Lower cover plate

[0048] 114-1, 114-2: Gaskets; 120: Current collection components

[0049] 121: Manifold

[0050] 122: Current collector

[0051] 130: Electrode assembly; 131: Upper insulation part

[0052] 132: Insulation board; 140: Housing Detailed Implementation

[0053] Embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Before the description, it should be noted that the terms or words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings, but should be understood to have meanings and concepts consistent with the spirit of this disclosure, based on the principle that the inventor is able to appropriately define the concept of each term so as to best describe his / her invention. The embodiments described in this specification and the configurations illustrated in the drawings are examples of this disclosure and do not cover all the technical ideas of this disclosure. Therefore, it should be understood that various changes and modifications can be made when this application is filed.

[0054] It will be further understood that, when used herein, the term “comprising” specifies the presence of the said feature, integer, step, operation, element, component, and / or group thereof, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0055] To facilitate understanding of this disclosure, the drawings may not be drawn to scale, and the dimensions of some parts may be enlarged. It should be noted that in different embodiments, the same reference numerals indicate the same parts.

[0056] Referring to two compared elements, features, etc., as “identical” means that they are “substantially identical.” Therefore, the phrase “substantially identical” can include deviations considered low in the art, such as approximately 5% or less. The uniformity of any parameter in a given region may mean that it is uniform from an average perspective.

[0057] Although terms such as "first" and / or "second" are used to describe various components, these components are of course not limited by these terms. These terms are used only to distinguish one component from another. Therefore, unless specifically stated otherwise, a first component may be referred to as a second component without departing from the teachings of the exemplary embodiments.

[0058] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0059] Arranging any component "above (or below)" or "on (or under)" a component may mean that any component is configured to contact the upper (or lower) surface of the component, and other components may be located between the component and any components positioned on (or below) the component.

[0060] It will be understood that when a component is referred to as “connected,” “joined,” or “engaged” to another component, it can be directly “connected,” “joined,” or “engaged” to the other component, or indirectly “connected,” “joined,” or “engaged” to the other component in the presence of other components in between.

[0061] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. The use of “may” in describing embodiments of this disclosure refers to “one or more embodiments of this disclosure.” Expressions such as “at least one of…” and “one or more of…” before / after the list of elements modify the entire list of elements, but not individual elements in the list.

[0062] Unless otherwise stated, throughout the specification, when “A and / or B” is stated, it means A, B, or A and B. Furthermore, unless explicitly stated otherwise, when “C to D” is stated, it means C and above and D and below.

[0063] When phrases such as “at least one of A, B and C”, “at least one of A, B or C”, “at least one selected from the group of A, B and C” or “at least one selected from A, B and C” are used to specify a list of elements A, B and C, the phrase can refer to any and all suitable combinations.

[0064] The term “use” may be considered synonymous with the term “utilization”. As used herein, the terms “substantially,” “about,” and similar terms are used as approximations rather than terms of degree and are intended to take into account the inherent variations in measurements or calculations that would be apparent to a person of ordinary skill in the art.

[0065] It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or segment from another element, component, region, layer, or segment. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment.

[0066] To facilitate explanation when describing the relationship between one element or feature and another element or feature as shown in the figures, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” are used herein. It will be understood that, in addition to the orientation depicted in the figures, spatial relative positions are also intended to cover different orientations of the device in use or operation. For example, if the device in the figures is flipped, any element described as “below” or “under” another element would be oriented as “above” or “above” another element. Therefore, the term “below” can include both upward and downward directions.

[0067] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure.

[0068] This disclosure will be described in detail with reference to the accompanying drawings.

[0069] Examples of secondary batteries include coin-shaped, cylindrical, prismatic, and pouch-shaped types. This disclosure is generally applicable to prismatic secondary batteries. Therefore, prismatic secondary batteries will be briefly described first before describing embodiments of this disclosure. However, aspects and features of this disclosure can be applied to other types of secondary batteries.

[0070] Figure 1A It is a top perspective view of a prismatic secondary battery based on existing technology, and Figure 1B It is along Figure 1A The cross-sectional view taken from line I-I' in the diagram.

[0071] First, the description Figure 1A The appearance of the prismatic secondary battery shown.

[0072] The housing 51 defines the overall appearance of the prismatic secondary battery and may be made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. The housing 51 may provide (or may be formed) space for housing the electrode assembly therein.

[0073] The cover assembly 60 may include a cover plate 61 that covers an opening in the housing 51, and the cover assembly 60 and the cover plate 61 may be made of a conductive material. The first terminal 62 and the second terminal 63 may be electrically connected to a positive electrode and a negative electrode (or a negative electrode and a positive electrode) inside the housing 51, respectively, and may be mounted to protrude outward through the cover plate 61.

[0074] The cover plate 61 may have an electrolyte inlet 64 formed with a sealing plug inserted therein and an exhaust 66 with a notch 65. The exhaust 66 is configured to degas the secondary battery, for example, to release excess gas generated inside the secondary battery.

[0075] refer to Figure 1B The internal structure of the prismatic secondary battery and its connection structure with the cover assembly 60 will be described.

[0076] like Figure 1B As shown, a prismatic secondary battery typically includes an electrode assembly 40, a first current collector 41, a first terminal 62, a second current collector 42, and a second terminal 63.

[0077] Electrode assembly 40 can be formed by winding or stacking a first electrode plate, a diaphragm, and a second electrode plate, both in the form of plates or films. When electrode assembly 40 is a wound laminate, it can have a winding axis parallel to the longitudinal direction of housing 51. Electrode assembly 40 can be stacked rather than wound, but the shape of electrode assembly 40 is not limited in this disclosure. Furthermore, electrode assembly 40 can be a Z-stacked electrode assembly in which the first and second electrode plates are inserted into both sides (e.g., opposite sides) of the diaphragm and then bent (or folded) into a Z-stacked form. In addition, electrode assembly 40 can include one or multiple electrode assemblies (or can be constituted therefrom) such that their long sides are adjacent to each other and are housed in housing 51, and the number of electrode assemblies is not limited in this disclosure. Electrode assembly 40 can have a first electrode plate serving as a negative electrode and a second electrode plate serving as a positive electrode, or vice versa.

[0078] The first electrode plate can be formed by coating a first electrode active material, such as graphite or carbon, onto a first electrode current collector plate formed of a metal foil, such as copper, a copper alloy, nickel, or a nickel alloy. The first electrode plate may include a first electrode tab (e.g., a first uncoated portion) 43, which is a region where the first electrode active material is not coated. The first electrode tab 43 can serve as a current flow channel between the first electrode plate and the first current collector portion 41. In some embodiments, when manufacturing the first electrode plate, the first electrode tab 43 can be formed by pre-cutting the first electrode plate to protrude to one side, or it can protrude to one side further than the diaphragm without separate cutting.

[0079] The second electrode plate can be formed by coating a second electrode active material, such as a transition metal oxide, onto a substrate made of a metal foil such as aluminum or an aluminum alloy. The second electrode plate may include a second electrode tab (e.g., a second uncoated portion) 44, which is a region where the second electrode active material is not coated. The second electrode tab 44 can serve as a current flow channel between the second electrode plate and the second current collector 42. In some embodiments, during the manufacture of the second electrode plate, the second electrode tab 44 can be formed by pre-cutting the second electrode plate to protrude to the other side, or it can protrude to the other side further than the diaphragm without separate cutting.

[0080] In some embodiments, the first electrode contact 43 may be located on the right end side of the electrode assembly 40, and the second electrode contact 44 may be located on the left end side of the electrode assembly 40. Optionally, the first electrode contact 43 and the second electrode contact 44 may be located on one end side (e.g., the same end side) in the same direction of the electrode assembly 40. Here, for ease of explanation, based on... Figure 1B The left and right sides are represented by a centrally oriented secondary battery, and its position can change when the secondary battery is rotated left and right or up and down.

[0081] The separator prevents short circuits between the first and second electrode plates while allowing lithium ions to migrate between them. The separator can be made of, for example, polyethylene membrane, polypropylene membrane, or polyethylene-polypropylene membrane.

[0082] The first electrode tab 43 of the first electrode plate and the second electrode tab 44 of the second electrode plate extend from both ends (e.g., opposite ends) of the electrode assembly 40 as described above. In some embodiments, the electrode assembly 40 may be housed together with the electrolyte in a housing 51.

[0083] In the electrode assembly 40, the first current collector 41 and the second current collector 42 can be welded and connected to the first electrode terminal 43 extending from the first electrode plate and the second electrode terminal 44 extending from the second electrode plate, respectively.

[0084] For reference Figure 1A The first current collector 41 and the second current collector 42 are respectively connected to the first terminal 62 and the second terminal 63 via terminal pins 67. In some embodiments, the terminal pins 67 may each have a threaded outer peripheral surface and can be fastened to the first terminal 62 and the second terminal 63 by threaded connection. However, this disclosure is not limited thereto. For example, the terminal pins 67 may also be connected to the first terminal 62 and the second terminal 63 by riveting or welding.

[0085] Figure 1A and Figure 1B The secondary battery shown can have a top terminal structure because the first terminal 62 and the second terminal 63 are located at the top of the housing 51. Figure 1A and Figure 1B Unlike the secondary battery shown, the first and second terminals can be located on opposite sides of the casing (e.g., opposite sides). This structure can be called a side-terminal structure. See below for reference. Figures 2A to 2D Describe a secondary battery with this side terminal structure.

[0086] Figure 2A This is a perspective view of a secondary battery with side terminals according to existing technology, and Figure 2B yes Figure 2A The diagram shows a cross-sectional view of the terminal portion of the secondary battery with side terminals. Figure 2C yes Figure 2A An exploded perspective view of the terminal portion of the secondary battery shown, and Figure 2D yes Figure 2A The diagram shows an exploded cross-sectional view of the terminal portion of the secondary battery with side terminals.

[0087] refer to Figure 2A The secondary battery with side terminals can be a secondary battery having a first terminal 62' and a second terminal 63' disposed on both sides (e.g., opposite sides or opposite ends) of the housing 51'. The first terminal 62' and the second terminal 63' can be disposed on both sides of the housing 51'. The arrangement of the electrode assembly and electrode terminals within the housing 51' can be similar to... Figure 1A and Figure 1B The arrangement of the secondary batteries is shown.

[0088] refer to Figure 2B and Figure 2C The terminal portion of the side-terminal secondary battery can be formed to have a direct connection structure because the first terminal portion 62' does not use, for example, Figure 1BIn the case of the terminal pin shown, it is directly connected to the current collector 41' in which the protrusions and recesses are formed. The current collector 41' may include a current collector plate 41'-1 electrically connected to the electrode assembly 40' and a current collector 41'-2 having protrusions and recesses. In this embodiment, a welding groove may be formed in the first terminal portion 62'. The first terminal portion 62' and the current collector 41' can be joined by welding at the welding groove and the protrusions and recesses by irradiating a laser into the welding groove in the first terminal portion 62' and the protrusions and recesses of the current collector 41'-2. In addition, an insulating member 68' may be provided between the cover plate 61' and the first terminal portion 62'.

[0089] like Figure 2D As shown, in the direct bonding structure according to the prior art, the welding method can be as follows: The current collector 41' can be first bonded to the electrode assembly 40'. The electrode assembly 40' can be housed in the housing 51'. Furthermore, when the cover assembly 60' has been disposed in the opening in the housing 51', the first terminal portion 62' and the current collector 41' can be bonded by irradiating a laser onto the welding groove of the first terminal portion 62' and the portion of the current collector 41'-2 that contacts each other, welding at the welding groove and the portion of the ... portion of the groove and the portion of the portion of the portion of the groove and the portion of the portion of the portion of the groove and the portion of the portion of the portion of the groove and the portion of the portion of the portion of the groove and the portion of the portion of the portion of the groove and the portion of the portion of the portion of the groove and the portion of the portion of the portion of the groove and the portion of the portion of the portion of the groove and the portion of the portion of the portion of the groove and the portion of the

[0090] As described above, in the direct bonding structure according to the prior art, the bonding of the first terminal portion 62' and the current collector 41' is performed under conditions where it is difficult to maintain an adhesive (or contact) state between the first terminal portion 62' and the current collector 41'. Therefore, poor connection may occur due to differences in component positions caused by the flatness (or unevenness) of the current collector 41'-2 or by movement of the unevenness of the current collector 41'-2. Therefore, the direct bonding structure according to the prior art may suffer from poor adhesion due to gaps between the welding surfaces.

[0091] Therefore, embodiments of the present disclosure that overcome these problems in the direct-connection structures according to the prior art are described below with reference to the accompanying drawings. As an example, embodiments of the present disclosure are described in conjunction with a secondary battery having a side-terminal structure (some of which will be described below with reference to the accompanying drawings), but the present disclosure is not limited thereto. Embodiments of the present disclosure can also be used with secondary batteries having a top-terminal structure.

[0092] Figure 3A This is a schematic diagram illustrating a cover assembly according to an embodiment of the present disclosure, and Figure 3B This is a cross-sectional view of the portion of the glass assembly that is joined to the cover assembly according to an embodiment of the present disclosure.

[0093] refer to Figure 3AAccording to embodiments of the present disclosure, the cover assembly 110 may include a terminal portion 111, a glass (e.g., a glass portion) 112, and a cover plate 113.

[0094] Terminal 111 can be electrically connected to the electrode plate of the electrode assembly. Terminal 111 can have a positive or negative polarity, and can have a polarity similar to... Figure 2A and Figure 2B The structure shown is the same, but terminal portion 111 has no polarity. In various embodiments, terminal portion 111 may be a terminal plate. Terminal portion 111 can electrically connect an external component (e.g., an external device or circuit) and a secondary battery using a conductive material. Terminal portion 111 may have a generally plate shape and may be disposed parallel to the top of the electrode assembly. In various embodiments, a welding groove to be combined with a protrusion formed in the current collector may be formed in terminal portion 111.

[0095] Glass 112 may be provided on the portion where the current collector of the current collector and the electrode assembly are joined, in connection with the electrode plate and terminal portion 111 of the electrically connected electrode assembly. Glass 112 may be made of a material capable of transmitting laser light (e.g., the glass may be light-transmitting). Laser light can pass through glass 112 and irradiate the portion where the current collector and the electrode assembly are joined because glass 112 is capable of transmitting laser light.

[0096] Terminal holes (e.g., terminal openings) that engage with terminal portions 111 and glass holes (e.g., glass openings) that engage with glass 112 can be formed in cover plate 113. Cover plate 113 can be coupled to a housing that houses the electrode assembly. Cover plate 113 can have an approximately rectangular plate shape and can be made of the same material as the housing. In one embodiment, cover plate 113 can have dimensions corresponding to the inside (e.g., interior) of the opening in the housing. Furthermore, in some embodiments, cover plate 113 can be coupled to the housing, such as by laser welding. Terminal holes and grooves or immersion holes for engaging with terminal portions 111 can be formed in cover plate 113.

[0097] exist Figure 3A and Figure 3BIn the illustrated embodiment, the cover plate 113 may include: an upper cover plate 113-1, wherein an upper glass hole (e.g., an upper glass opening) has been formed at the portion where it is already (or will be) joined with the glass 112; and a lower cover plate 113-2, wherein a mounting groove in which the glass 112 (or will be) disposed and a lower glass hole (e.g., a lower glass opening) have been formed at the portion where it is joined with the glass 112. In this embodiment, the cover plate 113 may include gaskets 114-1, 114-2 provided at the contact points between the upper cover plate 113-1 and the glass 112, and at the contact points between the lower cover plate 113-2 and the glass 112. When vibration or impact is applied to the portion where the cover plate 113 is joined with the glass 112, the gaskets 114-1, 114-2 can prevent damage to the glass 112. Further, as Figure 3B As shown, the upper cover plate 113-1 and the lower cover plate 113-2 of the cover plate 113 can be joined together by welding the portion A at the contact point between the upper cover plate 113-1 and the lower cover plate 113-2. In this embodiment, the welding method can be a laser welding method.

[0098] The following is for reference Figures 4A to 6 The structure of the secondary battery, including the cover assembly 110, and the method for manufacturing the secondary battery are described sequentially.

[0099] Figure 4A This is a perspective view illustrating the combination of the cover assembly and the flow collector according to an embodiment of the present disclosure. Figure 4B This is a side view illustrating the combination of the cover assembly and the current collector according to an embodiment of the present disclosure.

[0100] refer to Figure 4A and Figure 4B To manufacture a secondary battery including a cover assembly 110, the cover assembly 110 according to an embodiment of the present disclosure can first be manufactured. According to an embodiment of the present disclosure, the cover assembly 110 can be manufactured using the following process: After manufacturing a cover plate 113 in which terminal holes to be coupled with terminal portions 111 and glass holes to be coupled with glass 112 are formed, the terminal portions 111 of the electrode plates electrically connected to the electrode assembly can be coupled with the terminal holes. The laser-transmitting glass 112 (which is provided as being disposed on the portion where the current collector and the electrode assembly are coupled) can be coupled with the glass holes.

[0101] In various embodiments, the process of joining the glass 112 with the glass hole can be as follows. After the glass 112 is placed in the mounting groove formed in the lower cover plate 113-2 of the cover plate 113 and the upper cover plate 113-1 of the cover plate 113 is disposed above the lower cover plate 113-2, the upper cover plate 113-1 and the lower cover plate 113-2 can be joined by welding the portions of the upper cover plate 113-1 and the lower cover plate 113-2 that are in contact with each other.

[0102] When manufacturing the cover assembly 110 according to an embodiment of the present disclosure, the cover assembly 110 and the current collector 120 according to an embodiment of the present disclosure can be combined. A protrusion or recess to be coupled to the terminal portion 111 can be formed in the current collector 120. In various embodiments, the current collector 120 may include a current collector plate 121 electrically connected to an electrode assembly and a current collector 122 in which the protrusion or recess has been formed. Furthermore, a welding groove to be coupled to the protrusion or recess formed in the current collector 120 can be formed in the terminal portion 111. In such embodiments, such as Figure 4B As shown, the terminal portion 111 and the current collector 120 can be joined by welding the welding groove of the terminal portion 111 and the uneven portion of the current collector 122 at the point where the laser irradiates the welding groove of the terminal portion 111 and the uneven portion of the current collector 122 contact each other. As described above, according to the embodiments of this disclosure, the cover assembly 110 can improve product reliability and mass production rate by reducing or minimizing the risk of poor adhesion between the current collector 120 and the cover assembly 110, because the welding is performed in an adhesive state in which the welding groove of the terminal portion 111 and the uneven portion of the current collector 122 have been determined (or confirmed to have) contacted each other.

[0103] In various embodiments, the cover assembly 110 may include an upper insulating portion 131 disposed between the terminal portion 111 and the cover plate 113. The upper insulating portion 131 may have a rectangular plate shape corresponding to the shape of the terminal portion 111. The upper insulating portion 131 may be formed to be larger than the terminal portion 111 and may have a groove in which the terminal portion 111 is disposed.

[0104] Furthermore, in various embodiments, the cover assembly 110 may include an insulating plate 132 disposed between the cover plate 113 and the current collector 120. The insulating plate 132 may have an approximately rectangular plate shape. The insulating plate 132 may be tightly attached to the bottom of the cover plate 113 and may insulate the cover plate 113 from the electrode assembly. The plate surface or sides of the insulating plate 132 may have different shapes depending on the shape of the component to be insulated. Through holes (e.g., openings) corresponding to the positions of terminal holes and glass holes in the cover plate 113 may be formed in the insulating plate 132. A portion of the current collector 121 may be disposed below the insulating plate 132.

[0105] Figure 5A This is a perspective view illustrating the electrode assembly and current collector assembly after the cover assembly and current collector assembly have been combined, according to an embodiment of the present disclosure. Figure 5B This is a side view illustrating the electrode assembly and current collector after the cover assembly and current collector have been combined, according to an embodiment of the present disclosure.

[0106] refer to Figure 5A and Figure 5B The cover assembly 110 and the flow collector 120 are as described above. Figure 4A and Figure 4B After the aforementioned bonding, electrode assembly 130 can be bonded to current collector 120 after cover assembly 110 and current collector 120 have been bonded. In various embodiments, electrode assembly 130 and current collector 120 can be welded and bonded using a laser passing through glass 112. Figure 5A and Figure 5B As shown, with the cover assembly 110 and the current collector 120 already joined, when the joined cover assembly 110 and current collector 120 are disposed on the electrode assembly 130, the current collector plate 121, i.e., a portion of the current collector 120, can be exposed through the glass 112 (e.g., can be seen through the glass 112). The current collector plate 121 and the electrode assembly 130 can be welded and joined by irradiating the portion C exposed through the glass 112 with a laser.

[0107] As described above, in the direct bonding structure according to the prior art, after the electrode assembly and the current collector are bonded, the current collector and the terminal portion are bonded in a state where it is difficult to maintain adhesion between the current collector and the terminal portion. Therefore, there is a risk of poor connection due to differences in the flatness of the current collector or the position between the components, or poor adhesion due to gaps between the welded surfaces. However, in the direct bonding structure using the cover assembly 110 according to the embodiment of this disclosure, after bonding the current collector 120 and the terminal portion 111 while maintaining adhesion between the current collector 120 and the terminal portion 111, the electrode assembly 130 and the current collector 120 are bonded by laser welding through the glass 112. Therefore, because the risk of poor adhesion between the current collector 120 and the cover assembly 110 is reduced or minimized, product reliability and mass production rate can be improved.

[0108] Figure 6 This is a perspective view illustrating the assembly of the cover assembly and the housing after the cover assembly, current collector and electrode assembly have been combined, according to an embodiment of the present disclosure.

[0109] refer to Figure 6 According to embodiments of this disclosure, after the cover assembly 110, current collector 120, and electrode assembly 130 are joined as described above, the cover assembly 110, current collector 120, and electrode assembly 130 can be housed in the housing 140 in the joined state. Subsequently, when the cover assembly 110 and housing 140 are joined, a secondary battery according to embodiments of this disclosure can be manufactured. The cover assembly 110 and housing 140 can be joined using laser welding.

[0110] In the following, materials that can be used in a secondary battery according to an embodiment of the present disclosure are described.

[0111] Compounds capable of reversibly inserting and deintercalating lithium (e.g., lithiation intercalation compounds) can be used as positive electrode active materials. For example, one or more composite oxides of lithium with metals selected from cobalt, manganese, nickel, and combinations thereof can be used as positive electrode active materials.

[0112] The composite oxide can be a lithium transition metal composite oxide. Detailed examples of composite oxides may include lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free nickel manganese oxides, or combinations thereof.

[0113] For example, a compound represented by one 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); Li a Mn 1-b G bO2(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); and Li a FePO4 (0.90≤a≤1.8).

[0114] In the chemical formula, A can be Ni, Co, Mn, or a combination thereof; X can be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; D can be O, F, S, P, or a combination thereof; G can be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L 1 It can be Mn, Al, or a combination thereof.

[0115] The positive electrode for a lithium secondary battery may include a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0116] The content of the positive electrode active material can be in the range of about 90 wt.% to about 99 wt.% relative to 100 wt.% of the positive electrode active material layer. The contents of the binder and conductive material can each be in the range of about 0.5 wt.% to about 5 wt.% relative to 100 wt.% of the positive electrode active material layer.

[0117] Al foil can be used as a positive electrode current collector, but this disclosure is not limited thereto.

[0118] The negative electrode active material may include materials capable of reversibly inserting and de-intercalating lithium ions, lithium metal, lithium metal alloys, materials capable of doping and de-doping lithium, or transition metal oxides.

[0119] Materials capable of reversibly inserting and deintercalating lithium ions can include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, or combinations thereof. Examples of crystalline carbon can include graphite, such as natural or synthetic graphite. Examples of amorphous carbon can include soft or hard carbon, mesophase pitch carbides, and calcined coke.

[0120] Si-based or Sn-based negative electrode active materials can be used as materials capable of being doped and dedoped with lithium. Si-based negative electrode active materials can be silicon, silicon-carbon composites, SiO₂, etc. x(0 < x ≤ 2), Si-based alloys, or combinations thereof.

[0121] The silicon-carbon composite can be a composite of silicon and amorphous carbon. According to an exemplary embodiment, the silicon-carbon composite can include silicon particles and can have a form in which amorphous carbon is coated on the surface of the silicon particles.

[0122] The silicon-carbon composite can further include crystalline carbon. For example, the silicon-carbon composite can include a core containing crystalline carbon and silicon particles and an amorphous carbon coating provided on the surface of the core.

[0123] The negative electrode for a lithium secondary battery can include a negative electrode current collector and a negative electrode active material layer provided on the negative electrode current collector. The negative electrode active material layer can include a negative electrode active material and can further include a binder and / or a conductive material.

[0124] For example, the negative electrode active material layer can include a negative electrode active material in the range of about 90 wt.% to about 99 wt.%, a binder in the range of about 0.5 wt.% to about 5 wt.%, and a conductive material in the range of about 0 wt.% to about 5 wt.%.

[0125] A non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof can be used as the binder. If an aqueous binder is used as the binder for the negative electrode, the binder for the negative electrode can further include a cellulose-based compound capable of imparting viscosity.

[0126] One selected from a nickel foil, a stainless steel foil, a titanium foil, nickel foam, copper foam, a polymer matrix coated with a conductive metal, and combinations thereof can be used as the negative electrode current collector.

[0127] The electrolyte for a lithium secondary battery can include a non-aqueous organic solvent and a lithium salt.

[0128] The non-aqueous organic solvent serves as a medium through which ions participating in the electrochemical reaction of the battery can move.

[0129] The non-aqueous organic solvent can be a carbonate solvent, an ester solvent, an ether solvent, a ketone solvent, an alcohol solvent, an aprotic solvent, or a combination thereof. The carbonate solvent, the ester solvent, the ether solvent, the ketone solvent, the alcohol solvent, or the aprotic solvent can be used alone, or two or more of them can be mixed and used as the non-aqueous organic solvent.

[0130] In addition, if a carbonate solvent is used, a cyclic carbonate and a chain carbonate can be mixed and used.

[0131] Depending on the type of lithium-ion secondary battery, a separator can be present between the positive and negative electrodes. Polyethylene, polypropylene, and polyvinylidene fluoride, or multilayers having two or more layers of these materials, can be used as separators.

[0132] The membrane may include a porous substrate and a coating comprising organic, inorganic or a combination thereof disposed on one or both sides of the porous substrate.

[0133] Organic substances may include polyvinylidene fluoride-based heavy antibodies or (meth)acrylic acid polymers.

[0134] Inorganic materials 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 this disclosure is not limited thereto.

[0135] Organic and inorganic substances can be in the form of organic and inorganic substances mixed in a coating or in the form of coatings containing organic substances and coatings containing inorganic substances stacked together.

[0136] While this disclosure has been described above in conjunction with some embodiments, it is not limited to the embodiments described herein. Those skilled in the art to which this disclosure pertains can modify and alter this disclosure within the spirit and equivalent scope of the claims.

Claims

1. A cover assembly, comprising: The terminal section is configured to be electrically connected to the electrode plate of the electrode assembly; The glass portion through which the laser is transmitted is located above the area where the current collector of the electrode assembly, which is electrically connected to the electrode plate and the terminal portion, is combined with the electrode assembly; as well as A cover plate having a terminal opening that engages with the terminal portion and a glass opening that engages with the glass portion, and the cover plate being coupled to a housing that accommodates the electrode assembly.

2. The cover assembly according to claim 1, wherein a welding groove to be engaged with a protrusion or recess formed in the current collector is formed in the terminal portion.

3. The cover assembly according to claim 1, wherein the cover plate comprises: The upper cover plate has an upper glass opening formed in the upper cover plate at the portion where it joins with the glass portion; as well as The lower cover plate has a mounting groove therein in which the glass portion is disposed and a lower glass opening formed in the lower cover plate at the portion that is joined to the glass portion.

4. The cover assembly according to claim 3, further comprising gaskets respectively disposed at the contact points between the upper cover plate and the glass portion and at the contact points between the lower cover plate and the glass portion.

5. The cover assembly of claim 3, wherein the upper cover plate and the lower cover plate of the cover plate are joined together by welding the areas where the upper cover plate and the lower cover plate contact each other.

6. The cover assembly according to claim 1, further comprising an upper insulating portion between the terminal portion and the cover plate.

7. The cover assembly according to claim 1, further comprising an insulating plate between the cover plate and the current collecting member.

8. A secondary battery, comprising: Electrode assembly; Housing that houses the electrode assembly; The cover assembly is combined with the housing; as well as A current collector is electrically connected to the electrode plate of the electrode assembly and the terminal portion of the cover assembly. The cover assembly includes: The terminal portion is electrically connected to the electrode plate of the electrode assembly; The laser-transmitting glass portion is located above the region where the current collector and the electrode assembly are joined; and A cover plate having a terminal opening that engages with the terminal portion and a glass opening that engages with the glass portion, the cover plate being coupled to the housing.

9. The secondary battery of claim 8, wherein the electrode assembly and the current collector are welded by using a laser passing through the glass portion.

10. The secondary battery according to claim 8, wherein the current collector has a protrusion or recess for engaging with the terminal portion.

11. The secondary battery according to claim 10, wherein the terminal portion has a welding groove for engaging with the protrusion or recess in the current collector.

12. The secondary battery according to claim 8, wherein the cover plate comprises: The top cover has an upper glass opening at the portion where it engages with the glass section; as well as The lower cover plate has a mounting groove and a lower glass opening in the portion where the glass portion is joined.

13. The secondary battery of claim 12, wherein the cover assembly further comprises gaskets respectively disposed at the contact points between the upper cover plate and the glass portion and at the contact points between the lower cover plate and the glass portion.

14. The secondary battery of claim 12, wherein the upper cover and the lower cover of the cover plate are joined together by welding the areas where the upper cover and the lower cover plate contact each other.

15. The secondary battery of claim 8, wherein the cover assembly further includes an upper insulating portion between the terminal portion and the cover plate.

16. The secondary battery of claim 8, wherein the cover assembly further includes an insulating plate between the cover plate and the current collector.

17. A method for manufacturing a secondary battery, the method comprising: Manufacture a cover assembly, which is combined with a housing that houses the electrode assembly; The cover assembly and the current collection member are combined by combining the current collection member and the terminal portion of the cover assembly; The electrode plate of the electrode assembly and the terminal portion of the cover assembly are electrically connected by combining the current collector and the electrode assembly; The electrode assembly is housed within the housing; as well as Combining the cover assembly and the housing, The manufacture of the cover assembly includes: Manufacture a cover plate having a terminal opening that engages with the terminal portion and a glass opening that engages with a laser-transmitting glass portion; The terminal portion of the electrode plate electrically connected to the electrode assembly is coupled to the terminal opening; and The glass portion above the area where the current collector and the electrode assembly are combined is combined with the glass opening.

18. The method of claim 17, wherein the terminal portion of the electrode plate electrically connecting the electrode assembly and the cover assembly comprises combining the electrode assembly and the current collector by laser welding the electrode assembly and the current collector through the glass portion.

19. The method of claim 17, wherein combining the cover assembly and the current collector comprises welding the protrusion and recess of the current collector and the terminal portion through a welding groove in the terminal portion.

20. The method of claim 19, wherein combining the glass portion with the glass opening comprises: The glass portion is placed in the mounting groove in the lower cover plate of the cover plate; The upper cover plate is positioned above the lower cover plate; as well as The upper cover plate and the lower cover plate are joined together by welding the areas where they contact each other.

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