Secondary battery

Abstract

Provided is a secondary battery comprising: a stacked electrode assembly that includes a plurality of unit cells stacked in a first direction and electrode leads at both ends in a second direction perpendicular to the first direction; multifunctional terminal blocks (MTBs) provided at both ends of the stacked electrode assembly; and a laminated sheet surrounding the side surfaces of the stacked electrode assembly. The MTBs include: first assemblies including inner housings and electrode terminals that are accommodated in the inner housings and electrically connected to the electrode leads of the stacked electrode assembly; and second assemblies including outer housings, which at least partially surround the first assemblies, and venting (rupture) disks, which are coupled to the outer housings and rupture and release gas when the internal pressure increases.

Description

secondary batteries

[0001] The present invention relates to a secondary battery, and more particularly, to a secondary battery that is advantageous in implementing a large-capacity cell, is advantageous in configuring a battery pack due to its high degree of freedom and compatibility, and has improved safety.

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0092180, filed July 17, 2023, the entire disclosure of which is incorporated herein by reference.

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, including handsets, laptops, and cordless vacuum cleaners. Recently, improved energy density and economies of scale have dramatically reduced the per-unit manufacturing cost of secondary batteries. Furthermore, as the range of battery electric vehicles (BEVs) has increased to match that of fuel-powered vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0004] Meanwhile, demand for large-capacity battery packs for electric vehicles and other applications is increasing. Large-capacity battery packs installed in automobiles are expected to increase capacity and enhance safety.

[0005] The technical problem to be achieved by the present invention is to provide a secondary battery that is advantageous not only in implementing a large-capacity cell, but also in configuring a battery pack due to a high degree of freedom and compatibility, and has improved safety.

[0006] The present invention provides a secondary battery comprising: a stacked electrode assembly in which a plurality of unit cells are stacked in a first direction and have electrode leads at both ends in a second direction perpendicular to the first direction; a multifunctional terminal block (MTB) provided at both ends of the stacked electrode assembly; and a laminate sheet wrapping a side surface of the stacked electrode assembly; wherein the MTB comprises: a first assembly including an inner housing, and an electrode terminal portion housed in the inner housing and electrically connected to the electrode leads of the stacked electrode assembly; and an outer housing wrapping at least a portion of the first assembly, and a second assembly including a venting disk coupled to the outer housing and rupturing when internal pressure increases to discharge gas.

[0007] In some embodiments, the inner housing may include a second through hole communicating with the venting disk.

[0008] In some embodiments, a shield may be provided within the second through hole.

[0009] In some embodiments, the MTB may further include a bus bar electrically connecting the electrode leads of the stacked electrode assembly to the electrode terminal portion.

[0010] In some embodiments, the inner housing includes a middle body, wherein the middle body can support a connection between the electrode lead and the bus bar.

[0011] In some embodiments, the inner housing includes a bottom portion, the bottom portion being positioned below the bus bar and capable of preventing lower heat transfer.

[0012] In some embodiments, the inner housing may include an insulating material, and the outer housing may include a metallic material. /

[0013] In some embodiments, the outer housing has a terminal hole, and the electrode terminal portion can be exposed to the outside through the terminal hole provided in the outer housing.

[0014] In some embodiments, the MTB further includes a check valve, and the check valve may be configured to open to discharge internal gas when the internal pressure of the secondary battery is higher than a certain pressure, and to close again after the internal pressure is relieved.

[0015] In some embodiments, the MTB may further include an electrolyte inlet configured to inject an electrolyte.

[0016] Another aspect of the present invention provides a secondary battery, comprising: a stacked electrode assembly in which a plurality of unit cells are stacked in a first direction and have electrode leads at both ends in a second direction perpendicular to the first direction; a multifunctional terminal block (MTB) provided at both ends of the stacked electrode assembly; and a laminate sheet wrapping a side surface of the stacked electrode assembly; wherein the MTB includes: a first assembly including an inner housing, and an electrode terminal portion housed in the inner housing and electrically connected to the electrode leads of the stacked electrode assembly; and an outer housing wrapping at least a portion of the first assembly, and a second assembly including a check valve coupled to the outer housing; wherein the check valve is configured to open to discharge internal gas when an internal pressure of the secondary battery is higher than a predetermined pressure, and to close again after the internal pressure is relieved.

[0017] In some embodiments, the second assembly may further include a sealing member coupled to the outer housing and sealing the periphery of the electrode terminal portion.

[0018] In some embodiments, the second assembly may further include a rupture disk coupled to the outer housing and configured to rupture to release gas when internal pressure increases.

[0019] In some embodiments, the inner housing may include a second through hole communicating with the venting disk.

[0020] In some embodiments, a shield may be provided within the second through hole.

[0021] The secondary battery according to embodiments of the present invention is not only advantageous in implementing a large-capacity cell, but is also advantageous in configuring a battery pack due to its high degree of freedom and compatibility, and can have improved safety.

[0022] The effects that can be obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0023] Figure 1 is a perspective view showing the main parts of a secondary battery according to one embodiment of the present invention.

[0024] Figure 2 is a schematic perspective view showing the appearance of the laminate sheet removed from the secondary battery of Figure 1.

[0025] Fig. 3 is a perspective view showing the coupling relationship between the first assembly and the second assembly constituting the first MTB in the secondary battery of Fig. 1.

[0026] FIG. 4 is a schematic diagram showing the first MTB in the secondary battery of FIG. 1 as viewed from the first direction.

[0027] Figure 5 is a schematic diagram showing a cross-section of the first MTB cut along a plane perpendicular to the third direction and passing through the electrode terminal portion.

[0028] Figure 6 is a perspective view showing the main part of a secondary battery according to another embodiment of the present invention.

[0029] Fig. 7 is a partial perspective view showing the separation-combination structure of the first assembly and the second assembly of the first MTB of the secondary battery of Fig. 6.

[0030] Fig. 8 is a drawing showing the first assembly of the secondary battery of Fig. 6.

[0031] Fig. 9 is a drawing showing the separation structure of the first assembly of the secondary battery of Fig. 6.

[0032] Fig. 10 is a drawing showing the first assembly of the secondary battery of Fig. 6 as viewed from the second direction.

[0033] Fig. 11 is a perspective view showing a second assembly of the secondary battery of Fig. 6.

[0034] Fig. 11 is a perspective view showing the separation structure of the second assembly of the secondary battery of Fig. 6.

[0035] Figures 13 and 14 are perspective views showing the form in which the first assembly and the second assembly are coupled to each other.

[0036] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments of the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. It is preferable to interpret that the embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art. Like numbers refer to like elements throughout. Furthermore, various elements and areas in the drawings are schematically drawn. Therefore, the present invention is not limited by the relative sizes or intervals depicted in the accompanying drawings.

[0037] While terms like "first" and "second" may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, a first component could be referred to as a "second component," and vice versa, without departing from the scope of the present invention.

[0038] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the inventive concept. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the expressions “comprises” or “has” indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, operations, components, parts, or combinations thereof.

[0039] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, it is to be understood that commonly used terms, such as those defined in dictionaries, should be interpreted to have a meaning consistent with their meaning within the relevant technical context, and should not be interpreted in an overly formal sense unless explicitly defined herein.

[0040] In some embodiments, where implementations are otherwise feasible, specific process sequences may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously, or in a reverse order from the described order.

[0041] In the accompanying drawings, variations in the shapes depicted may be expected, for example, depending on manufacturing techniques and / or tolerances. Therefore, embodiments of the present invention should not be construed as being limited to the specific shapes of the regions depicted herein, but should include, for example, changes in shapes resulting from the manufacturing process. All terms "and / or" used herein include each and every combination of one or more of the mentioned components. In addition, the term "substrate" used herein may mean the substrate itself, or a laminated structure including the substrate and a predetermined layer or film formed on the surface thereof. In addition, the "surface of the substrate" in this specification may mean the exposed surface of the substrate itself, or the outer surface of a predetermined layer or film formed on the substrate.

[0042]

[0043] (Example 1)

[0044] Fig. 1 is a perspective view showing the main part of a secondary battery (100) according to one embodiment of the present invention. Fig. 2 is a schematic perspective view showing the secondary battery (100) of Fig. 1a with the laminate sheet (170) removed.

[0045] In the drawings below, the secondary battery (100) is illustrated as being defined in a vertical coordinate system defined by a first direction along the X-axis, a second direction along the Y-axis, and a third direction along the Z-axis, which are perpendicular to each other, but the first direction, the second direction, and the third direction are not particularly limited as long as they are relatively perpendicular to each other.

[0046] Referring to FIGS. 1 and 2, the secondary battery (100) includes a stacked electrode assembly (110), a multifunctional terminal block (MTB) (120a, 120b), and a laminate sheet (170).

[0047] The stacked electrode assembly (110) may include a plurality of unit cells (111) stacked in a first direction (e.g., X-axis direction). Each of the unit cells (111) may have an electrode material applied on a metal foil that acts as a current collector.

[0048] Each of the unit cells (111) may have a thin plate-shaped body extending in a second direction (e.g., the Y-axis direction). Each of the unit cells (111) may be a positive electrode unit cell or a negative electrode unit cell. In some embodiments, the plurality of unit cells (111) may be formed by alternately stacking positive electrode unit cells and negative electrode unit cells one by one. The positive electrode unit cell and the negative electrode unit cell may be separated from each other by a separator.

[0049] In some other embodiments, the plurality of unit batteries (111) may be formed by alternately stacking a plurality of positive unit batteries and a plurality of negative unit batteries. The plurality of positive unit batteries and the plurality of negative unit batteries may be separated from each other by a separator.

[0050] The stacked electrode assembly (110) may have electrode leads (116) at both ends in the second direction (e.g., Y-axis direction). The electrode leads (116) may be electrically connected to electrode tabs of the plurality of unit cells (111). One or more electrode tabs may be connected to one electrode lead (116). In some embodiments, two or more electrode tabs may be connected to one electrode lead (116).

[0051] In some embodiments, the stacked electrode assembly (110) may have two electrode leads (116) on one side and two electrode leads (116) on the other side. In this case, half of the plurality of unit cells (111) included in the stacked electrode assembly (110) may be coupled to the first electrode lead on one side and coupled to the second electrode lead on the other side. In addition, the remaining half of the plurality of unit cells (111) included in the stacked electrode assembly (110) may be coupled to the third electrode lead on one side and coupled to the fourth electrode lead on the other side. However, the present invention is not limited thereto.

[0052] In some embodiments, the stacked electrode assembly (110) may have one or more electrode leads on one side. In some embodiments, the stacked electrode assembly (110) may have one or more electrode leads on the other side.

[0053] A first MTB (120a) may be provided at one end of the stacked electrode assembly (110) in the second direction (e.g., Y-axis direction), and a second MTB (120b) may be provided at the other end. One of the first MTB (120a) and the second MTB (120b) may be electrically connected to the positive electrode side of the stacked electrode assembly (110), and the other may be electrically connected to the negative electrode side of the stacked electrode assembly (110). The second MTB (120b) may have substantially the same configuration as the first MTB (120a), except that the polarity is different.

[0054] The laminate sheet (170) may be configured to wrap a side surface of the stacked electrode assembly (110). In some embodiments, the laminate sheet (170) may be attached to a side surface of the MTB (120a, 120b) so as to at least partially cover the side surface of the MTB (120a, 120b). In some embodiments, the laminate sheet (170) may cover all of the side surfaces of the MTB (120a, 120b) that are parallel to the second direction (e.g., the Y-axis direction). In some other embodiments, the laminate sheet (170) may cover only a portion of the side surfaces of the MTB (120a, 120b) that are parallel to the second direction (e.g., the Y-axis direction).

[0055] Hereinafter, the first MTB (120a) will be described. In the following description, the first MTB (120a) will be described, but a person skilled in the art will be able to understand the configuration of the second MTB (120b) from this.

[0056] FIG. 3 is a perspective view showing the coupling relationship between the first assembly (130) and the second assembly (140) constituting the first MTB (120a) in the secondary battery of FIG. 1.

[0057] The above first MTB (120a) may include a first assembly (130) and a second assembly (140).

[0058] The first assembly (130) may include an inner housing (131), an electrode terminal portion (132) accommodated within the inner housing (131), and a bus bar (133) electrically connecting the electrode terminal portion (132) and the electrode lead (116).

[0059] The inner housing (131) may be made of a non-conductive injection material. The inner housing (131) may define the positions of the electrode terminal portion (132) and the bus bar (133), and protect the electrode terminal portion (132) and the bus bar (133) from impact and movement due to external force.

[0060] The inner housing (131) may include a head portion (131s), a first through hole (131h1), a middle body (131t), a second through hole (131h2), and a bottom portion (131u).

[0061] The head portion (131s) constitutes the upper portion of the inner housing (131). The head portion (131s) may have a predetermined three-dimensional shape.

[0062] The first through-hole (131h1) is formed in the head portion (131s) and is a portion into which the electrode terminal portion (132) can be inserted. The first through-hole (131h1) may be provided in the head portion (131s) of the inner housing (131) so that the electrode terminal portion (132) is exposed toward the second direction (e.g., Y-axis direction). Therefore, the first through-hole (131h1) may be provided on a plane perpendicular to the second direction (e.g., Y-axis direction) of the head portion (131s). In addition, the first through-hole (131h1) may have an opening that is open in the longitudinal direction of the electrode assembly (110). The shape of the first through-hole (131h1) may be configured to match the outer shape of the portion where the electrode terminal portion (132) is exposed to the outside.

[0063] In some embodiments, the head portion (131s) may include a thread protrusion (131g) formed around the first through hole (131h1). The thread protrusion (131g) is formed around the first through hole (131h1) and may protrude in the second direction (e.g., Y-axis direction). Accordingly, when the electrode terminal portion (132) is inserted into the first through hole (131h1), the thread protrusion (131g) may surround the periphery of the electrode terminal portion (132) and prevent moisture from penetrating between the electrode terminal portion (132) and the first through hole (131h1). In addition, the outer housing (141) described below and the electrode terminal portion (132) may be electrically insulated.

[0064] The middle body (131t) constitutes the middle part of the inner housing (131) and is an erected part with a predetermined height.

[0065] FIG. 4 is a schematic diagram showing the first MTB in the secondary battery of FIG. 1 as viewed in a first direction (e.g., in the X-axis direction).

[0066] In some embodiments, the side surface of the middle body (131t) may be configured as a support surface. By providing the middle body (131t) with a support surface, the pressing force applied to the bus bar (133) and the electrode lead (116) when the bus bar (133) and the electrode lead (116) are joined to each other (e.g., by laser welding) can be supported.

[0067] In some embodiments, a second through hole (131h2) may be formed in the middle body (131t). The second through hole (131h2) may be provided on a plane perpendicular to the second direction (e.g., the Y-axis direction) of the middle body (131t). In addition, the second through hole (131h2) may have an opening that is open in the longitudinal direction of the electrode assembly (110). The second through hole (131h2) may be formed as a space through which heat, gas, etc. may be discharged.

[0068] In some embodiments, a shield (131k) may be provided within the second through-hole (131h2). The shield (131k) may be a predetermined extension beam extending across or vertically within the second through-hole (131h2). The shield (131k) may partially block the discharge of high-temperature particles during thermal runaway. Accordingly, the possibility of flame generation may be reduced.

[0069] The above second through hole (131h2) can communicate with the venting hole (141h2) of the outer housing (141) of the second assembly (140) described later and the venting disk (142) coupled to the venting hole (141h2).

[0070] The bottom portion (131u) constitutes the lower portion of the inner housing (131). The bottom portion (131u) can support the bus bar (133) and the electrode lead connected to the bus bar (133) from below. The bottom portion (131u) can block heat transfer so that heat transferred through the bus bar (133) and the electrode lead is not transferred downward.

[0071] The electrode terminal portion (132) is accommodated within the inner housing (131) and can be exposed through the first through hole (131h1). The electrode terminal portion (132) can be made of a metal or metal alloy having low electrical resistance, and can be, for example, an alloy containing copper (Cu), aluminum (Al), nickel (Ni), iron (Fe), platinum (Pt), manganese (Mn), or one or more thereof.

[0072] In some embodiments, the exposed surface of the electrode terminal portion (132) exposed to the outside from the inner housing (131) may be a plane. In some embodiments, the exposed surface may have a plane extending perpendicular to the second direction (e.g., the Y-axis direction).

[0073] Figure 5 is a schematic diagram showing a cross-section of the first MTB (120a) cut along a plane perpendicular to the third direction (e.g., Z-axis direction) passing through the electrode terminal portion (132).

[0074] Referring to FIG. 5, the bus bar (133) may be provided to make surface contact with the electrode terminal portion (132). The bus bar (133) may be made of a metal material having low electrical resistance. In some embodiments, the bus bar (133) may be made of copper (Cu), nickel (Ni), aluminum (Al), iron (Fe), cobalt (Co), platinum (Pt), molybdenum (Mo), tin (Sn), palladium (Pd), or an alloy including one or more of these. The bus bar (133) may secure a cross-sectional area capable of satisfying the allowable current value of the bus bar (133).

[0075] The bus bar (133) may be configured to make surface contact with the electrode lead (116) of the stacked electrode assembly (110). In some embodiments, the bus bar (133) may be joined to the electrode lead (116) by laser welding. In some embodiments, the bus bar (133) may be joined to the electrode lead (116) by a fastener, for example, by a rivet.

[0076] In some embodiments, the bus bar (133) may include a center portion (133c) having a planar shape extending horizontally in the first direction (e.g., X-axis direction) and an edge portion (133e) extending by bending from the center portion (133c). The center portion (133c) may be configured to form a generally U-shaped cross-sectional shape together with the edge portion (133e) and may extend in the third direction (e.g., Z-axis direction). In some embodiments, the edge portion (133e) may have a plane extending perpendicular to the first direction (e.g., X-axis direction).

[0077] The above bus bar (133) can make surface contact with the electrode terminal portion (132) at the center portion (133c). The above bus bar (133) can make surface contact with the electrode lead (116) at the edge portion (133e).

[0078] As described above, in some embodiments, the inner housing (131) may have a middle body (131t) having a support surface on a side surface. In this way, by having the middle body (131t), when the bus bar (133) and the electrode lead (116) are joined to each other (e.g., by laser welding), the middle body (131t) can support the pressing force (arrow V in FIG. 5) applied to the bus bar (133) and the electrode lead (116).

[0079] In some embodiments, the electrode lead (116) may include a pre-bended portion (116c) that is bent at a portion that does not contact the bus bar (133). The pre-bended portion (116c) may prevent stress from being concentrated at a specific portion of the electrode lead (116) due to an external force applied to the stacked electrode assembly (110), thereby improving safety.

[0080] Referring again to FIG. 3, the second assembly (140) is described as follows.

[0081] The second assembly (140) may include an outer housing (141) and a venting disc (142) coupled to the outer housing (141).

[0082] The outer housing (141) may be made of a material having relatively high rigidity, such as metal, and defines the exterior of the first MTB (120a). In some embodiments, the outer housing (141) may be made of aluminum (Al), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), manganese (Mn), or an alloy containing one or more of these.

[0083] In some embodiments, the outer housing (141) may include a terminal hole (141h1).

[0084] The terminal hole (141h1) is a portion where the electrode terminal portion (132) included in the first assembly (130) can be exposed when the first assembly (130) and the second assembly (140) are combined. The terminal hole (141h1) may be provided on the upper portion of the outer housing (141) so that the electrode terminal portion (132) is exposed toward the second direction (e.g., the Y-axis direction). Accordingly, the terminal hole (141h1) may be provided on a plane perpendicular to the second direction (e.g., the Y-axis direction) of the outer housing (141). The shape of the terminal hole (141h1) may be configured to conform to the outer shape of the portion where the electrode terminal portion (132) is exposed to the outside, but to be spaced apart from the electrode terminal portion (132).

[0085] In some embodiments, as described above, the inner housing (131) has a sealing portion (131g), and the sealing portion (131g) can space between the electrode terminal portion (132) and the inner periphery of the terminal hole (141h1). Accordingly, the electrode terminal portion (132) and the outer housing (141) can be electrically insulated from each other.

[0086] In some embodiments, the outer housing (141) may include a venting hole (141h2).

[0087] The venting hole (141h2) may be provided on a plane perpendicular to the second direction (e.g., Y-axis direction) of the outer housing (141). The shape of the venting hole (141h2) may be configured to match the shape of the venting disk (142) described below.

[0088] The venting hole (141h2) can communicate with the second through hole (131h2).

[0089] In some embodiments, the outer housing (141) may be coupled to the inner housing (131) in a form that surrounds at least a portion of the inner housing (131). That is, the outer housing (141) may have a coupling structure that surrounds at least a portion of the inner housing (131) in the first direction (e.g., the X-axis direction) and the second direction (e.g., the Y-axis direction). By coupling the outer housing (141) to the inner housing (131), the rigidity of the first MTB (120a) is supplemented, and the outer housing (141) has a module form that is equipped with multiple functions such as a gas venting structure, an electrolyte inlet, and a valve, so that it is advantageous for configuring a battery pack due to a high degree of freedom and compatibility, and improved safety can be implemented.

[0090] In some embodiments, the outer housing (141) and the inner housing (131) are joined to each other through a PP layer, an adhesive material, a welding structure, or the like. Therefore, moisture and foreign substances can be prevented from penetrating into the interior of the first MTB (120a).

[0091] In some embodiments, the first MTB (120a) may include a venting disk (142) configured to rupture when the internal pressure of the secondary battery (100) excessively increases, thereby releasing gas that causes the excessively increased internal pressure. The venting disk (142) is not restored to its original state when it ruptures due to a thermal event occurring within the secondary battery (100). The venting disk (142) may be any venting disk (142) known in the art and is not particularly limited.

[0092] The above venting hole (141h2) and the venting disk (142) may have a predetermined area. Since the venting hole (141h2) and the venting disk (142) have a predetermined area, an appropriate venting area can be secured when the venting disk (142) ruptures and thermal runaway occurs due to a thermal event occurring inside the secondary battery (100).

[0093] In some embodiments, the first MTB (120a) may further include a check valve (not shown). The check valve (not shown) may be configured to open to discharge internal gas when the internal pressure of the secondary battery (100) rises above a predetermined pressure, and to close again when the internal pressure is relieved by the discharge of the gas. Since the check valve (not shown) does not have a portion that is ruptured by the discharge of the gas, it can be restored to its original state after the discharge of the internal gas.

[0094] In some embodiments, the first MTB (120a) may further include an electrolyte injection port (not shown) for injecting electrolyte. In some embodiments, the electrolyte injection port (not shown) may be provided in only one of the first MTB (120a) and the second MTB (120b).

[0095] The electrolyte injected through the electrolyte injection port (not shown) may be an electrolyte used for a typical lithium secondary battery, and is not particularly limited.

[0096] Since the secondary battery (100) of the present invention accommodates all units having respective functions within the MTB (120a, 120b), such as an electrode terminal portion (132), a bus bar (133), a venting disk (142), a check valve (not shown), and an electrolyte injection port (not shown), the battery cell itself has a function equivalent to a conventional battery module. Therefore, the secondary battery (100) of the present invention can have a high degree of freedom and compatibility, and is advantageous for implementing cell-to-pack.

[0097]

[0098] (Example 2)

[0099] Fig. 6 is a perspective view showing a main part of a secondary battery (100a) according to another embodiment of the present invention. Fig. 7 is a partial perspective view showing a separation-combination structure of a part of the secondary battery (100a) of Fig. 6.

[0100] The secondary battery (100a) includes a first MTB (120a-1), and the first MTB (120a-1) is different from the first embodiment described with reference to FIGS. 1 to 5 in that the inner housing (151) of the first assembly (150) includes a front body (151a) and a rear body (151b), and a third through hole (151h3) is further formed in the front body (151a) in addition to the first through hole (151h1) and the second through hole (151h2), and the second assembly (160) further includes a seal member (163) and a check valve (164), and a valve hole (161h3) is further formed in the outer housing (161) in addition to the terminal hole (161h1) and the venting hole (161h2). Therefore, the following description will focus on these differences, and additional description will be omitted for overlapping parts.

[0101] FIG. 8 is a drawing showing a first assembly (150) of a secondary battery (100a) of the second embodiment, FIG. 9 is a drawing showing a separation structure of the first assembly (150) of the secondary battery (100a) of the second embodiment, and FIG. 10 is a drawing showing the first assembly (150) of the secondary battery (100a) of the second embodiment as seen from a second direction (for example, forward in the Y-axis direction).

[0102] The first assembly (150) of the second embodiment may include an inner housing (151), an electrode terminal portion (152) accommodated within the inner housing (151), and a bus bar (153) electrically connecting the electrode terminal portion (152) and the electrode lead (116).

[0103] The inner housing (151) may include a front body (151a) and a rear body (151b).

[0104] The front body (151a) constitutes the front (e.g., front in the Y-axis direction) body of the inner housing (151).

[0105] The first to third through holes (151h1, 151h2, 151h3) penetrate the front body (151a) in the second direction (e.g., Y-axis direction).

[0106] The first through-hole (151h1) described above corresponds to the first through-hole (131h1) described in the first embodiment as a portion into which the electrode terminal portion (152) can be inserted. The first through-hole (151h1) may be provided in the front body (151a) so that the electrode terminal portion (152) is exposed toward the second direction (e.g., Y-axis direction). Accordingly, the first through-hole (151h1) may be provided on a plane perpendicular to the second direction (e.g., Y-axis direction) of the front body (151a).

[0107] The second through hole (151h2) may be provided on a plane perpendicular to the second direction (e.g., Y-axis direction) of the front body (151a). In addition, the second through hole (151h2) may have an opening that is open in the longitudinal direction of the electrode assembly (110).

[0108] In some embodiments, a shield (151k) may be provided within the second through-hole (151h2). The shield (151k) may be a predetermined extension beam extending across or vertically within the second through-hole (151h2). The shield (151k) may partially block the discharge of high-temperature particles during thermal runaway. Therefore, the possibility of flame generation may be reduced.

[0109] The third through hole (151h3) may be provided on a plane perpendicular to the second direction (e.g., Y-axis direction) of the front body (151a). In addition, the second through hole (151h2) may have an opening that is open in the longitudinal direction of the electrode assembly (110). The shape of the third through hole (151h3) may be configured to match the shape of at least a portion of the check valve (164) described later.

[0110] The rear body (151b) constitutes the rear (e.g., rear in the Y-axis direction) body of the inner housing (151).

[0111] The above rear body (151b) may include a rear middle body (151t) and a rear bottom portion (151u).

[0112] The rear middle body (151t) is an erected portion having a predetermined height. The side of the rear middle body (151t) can support the pressure applied to the bus bar (153) and the electrode lead (116) when the bus bar (153) and the electrode lead (116) are joined to each other (e.g., by laser welding).

[0113] The rear bottom portion (151u) constitutes the lower portion of the rear body (151b). The rear bottom portion (151u) can support the bus bar (153) and the electrode leads connected to the bus bar (153) from below. The rear bottom portion (151u) can block heat transfer so that heat transferred through the bus bar (153) and the electrode leads is not transferred downward.

[0114] The above bus bar (153) can be configured to make surface contact with the electrode lead (116) of the stacked electrode assembly (110).

[0115] In some embodiments, the bus bar (153) may include a center portion (153c) having a planar shape extending horizontally in the first direction (e.g., X-axis direction) and an edge portion (153e) extending by bending from the center portion (153c). The bus bar (153) may make surface contact with the electrode terminal portion (152) at the center portion (153c). The bus bar (153) may make surface contact with the electrode lead (116) at the edge portion (153e).

[0116] In some embodiments, the bus bar (153) may include a first bus hole (153t). The first bus hole (153t) may be a hole penetrating the center portion (153c) in the second direction (e.g., the Y-axis direction). The first bus hole (153t) may be a portion connected to the electrode terminal portion (152).

[0117] In some embodiments, the bus bar (153) may include a second bus hole (153h). The second bus hole (153h) may be a hole that penetrates the center portion (153c) in the second direction (e.g., the Y-axis direction). The second bus hole (153h) may be positioned on the same line as the second through hole (151h2) in the second direction (e.g., the Y-axis direction). The second bus hole (153h), together with the second through hole (151h2), may function as a heat and gas exhaust passage.

[0118] Fig. 11 is a drawing showing a second assembly (160) of the second embodiment, and Fig. 12 is a drawing showing a separation structure of the second assembly (160).

[0119] The second assembly (160) of the second embodiment may include, in addition to the outer housing (161), a venting disc (162) coupled to the outer housing (161), a seal member (163), and a check valve (164).

[0120] Meanwhile, in some embodiments, the venting disk (162) may include a venting cover (162a) and venting insulation (162b) coupled to the venting cover (162a). However, the venting disk (162) may have any configuration.

[0121] The outer housing (161) may have a configuration in which a valve hole (161h3) is further formed in the first embodiment described above.

[0122] The valve hole (161h3) is a portion where the check valve (164) connected to the third hole of the first assembly (150) can be exposed when the first assembly (150) and the second assembly (160) are combined. The valve hole (161h3) may be provided at the lower portion of the outer housing (161) so that the check valve (164) is exposed toward the second direction (e.g., Y-axis direction). The valve hole (161h3) may conform to the outer shape of the portion where the check valve (164) is exposed to the outside.

[0123] In some embodiments, the second assembly (160) may include a seal member (163). The seal member (163) may be inserted into a terminal hole (161h1) of the outer housing (161). The seal member (163) is configured in a ring shape having a seal hole (163h), and an electrode terminal portion (152) may be positioned within the seal hole (163h) of the seal member (163). The seal member (163) may be configured of an insulating material and may electrically insulate the electrode terminal portion (152) from the outer housing (161).

[0124] The sealing member (163) can seal the area between the periphery of the electrode terminal portion (152) and the terminal hole (161h1) of the outer housing (161). Therefore, moisture can be prevented from penetrating into the gap between the terminal hole (161h1) and the electrode terminal portion (152).

[0125] In some embodiments, the second assembly (160) may include a check valve (164). The check valve (164) may have any configuration, and may include, for example, a membrane. The check valve (164) may be configured to open to discharge internal gas when the internal pressure of the secondary battery (100) becomes higher than a predetermined pressure, and to close again when the internal pressure is relieved by the discharge of the gas. Since the check valve (164) does not have a part that is ruptured by the discharge of the gas, it can be restored to its original state after the discharge of the internal gas.

[0126] Figures 13 and 14 are drawings showing a form in which the first assembly (150) and the second assembly (160) are coupled to each other.

[0127] In some embodiments, the outer housing (161) may be coupled to the inner housing (151) in a manner that surrounds at least a portion of the inner housing (151). Accordingly, the rigidity of the first MTB (120a) is supplemented, and moisture can be prevented from penetrating into the interior of the first MTB (120a).

[0128]

[0129] While the embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims. Therefore, modifications to future embodiments of the present invention will not depart from the scope of the invention.

[0130]

[0131] [Explanation of symbols]

[0132] 100, 100a: secondary battery

[0133] 110: Stacked electrode assembly

[0134] 111: Unit battery

[0135] 116: Electrode lead

[0136] 120a, 120b, 120c: MTB

[0137] 120a-1: 1st MTB

[0138] 130: First Assembly

[0139] 131: Inner housing

[0140] 131k: Head

[0141] 131h1: First penetration hole

[0142] 131h2: Second penetration

[0143] 131k: Shield

[0144] 131g: Real stone

[0145] 131t: Middle body

[0146] 131s: Bottom

[0147] 132: Electrode terminal section

[0148] 133: Busbar

[0149] 133c: Center section

[0150] 133e: Edge

[0151] 140: Second Assembly

[0152] 141: Outer housing

[0153] 141h1: Terminal Hall

[0154] 141h2: Venting Hall

[0155] 142: Venting disc

[0156] 150: First Assembly

[0157] 151: Inner housing

[0158] 151a: Front body

[0159] 151b: Rear body

[0160] 151h1: First penetration hole

[0161] 151h2: Second penetration hole

[0162] 151k: Shield

[0163] 151h3: Third penetration

[0164] 151t: Rear middle body

[0165] 151s: Rear bottom

[0166] 152: Electrode terminal section

[0167] 153: Busbar

[0168] 153c: Center section

[0169] 153e: Edge

[0170] 153t: Bus Hall 1

[0171] 153h: Bus Hall 2

[0172] 160: Second Assembly

[0173] 161: Outer housing

[0174] 161h1: Terminal Hall

[0175] 161h2: Venting Hall

[0176] 161h3: Valve hole

[0177] 162: Venting disc

[0178] 162a: Venting cover

[0179] 162b: Venting Insulation

[0180] 163: Real absence

[0181] 163h: Real Hall

[0182] 164: Check valve

[0183] 170: Laminate sheet

Claims

1. A stacked electrode assembly in which a plurality of unit cells are stacked in a first direction and have electrode leads at both ends in a second direction perpendicular to the first direction; A multifunctional terminal block (MTB) provided at both ends of the stacked electrode assembly; and A laminate sheet covering the side of the stacked electrode assembly; Includes, The above MTB is, A first assembly including an inner housing, and an electrode terminal portion housed in the inner housing and electrically connected to the electrode lead of the stacked electrode assembly; and A secondary battery comprising: an outer housing surrounding at least a portion of the first assembly; and a second assembly including a venting disk coupled to the outer housing and configured to rupture when internal pressure increases to discharge gas.

2. In paragraph 1, The above inner housing, A secondary battery characterized by including a second through hole communicating with the venting disk.

3. In paragraph 2, Within the above second through hole, A secondary battery characterized by being provided with a shield.

4. In paragraph 1, A secondary battery characterized in that the above MTB further includes a bus bar electrically connecting the electrode lead of the stacked electrode assembly and the electrode terminal portion.

5. In paragraph 4, The above inner housing, Includes middle body, The above middle body, A secondary battery characterized by supporting a connection between the electrode lead and the bus bar.

6. In paragraph 4, The above inner housing, Including the bottom part, A secondary battery characterized in that the bottom portion is located below the bus bar and prevents lower heat transfer.

7. In paragraph 1, The above inner housing includes an insulating material, The above outer housing is a secondary battery including a metal material.

8. In paragraph 1, The above outer housing has a terminal hole, A secondary battery characterized in that the electrode terminal portion is exposed to the outside through the terminal hole provided in the outer housing.

9. In paragraph 1, The above MTB further includes a check valve, A secondary battery characterized in that the check valve is configured to open to discharge internal gas when the internal pressure of the secondary battery is higher than a certain pressure, and to close again after the internal pressure is relieved.

10. In paragraph 1, A secondary battery characterized in that the above MTB further includes an electrolyte injection port configured to inject an electrolyte.

11. A stacked electrode assembly in which a plurality of unit cells are stacked in a first direction and have electrode leads at both ends in a second direction perpendicular to the first direction; A multifunctional terminal block (MTB) provided at both ends of the stacked electrode assembly; and A laminate sheet covering the side of the stacked electrode assembly; Includes, The above MTB is, A first assembly including an inner housing, and an electrode terminal portion housed in the inner housing and electrically connected to the electrode lead of the stacked electrode assembly; and A second assembly comprising an outer housing surrounding at least a portion of the first assembly, and a check valve coupled to the outer housing; A secondary battery characterized in that the check valve is configured to open to discharge internal gas when the internal pressure of the secondary battery is higher than a certain pressure, and to close again after the internal pressure is relieved.

12. In paragraph 11, The above second assembly, A secondary battery characterized in that it further includes a sealing member that is coupled to the outer housing and seals the periphery of the electrode terminal portion.

13. In paragraph 11, The above second assembly, A secondary battery further comprising a venting disk coupled to the outer housing and configured to rupture and discharge gas when internal pressure increases.

14. In paragraph 12, The above inner housing, A secondary battery characterized by including a second through hole communicating with the venting disk.

15. In paragraph 14, Within the above second through hole, A secondary battery characterized by being provided with a shield.

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