Battery cell and battery assembly comprising same

Abstract

The technical concept of the present invention provides a battery cell comprising: an electrode assembly; a cover sheet which comprises a main body part surrounding the electrode assembly and a bonded sealing part extending from one side of the main body part in a first direction; and a first multifunctional terminal block (MTB) which is at one end of the electrode assembly and comprises a first housing connected to the main body part of the cover sheet, wherein the width of the bonded sealing part at the center of the bonded sealing part is smaller than that at the edges thereof.

Description

Battery cells and battery assemblies containing the same

[0001] The present invention relates to a battery cell and a battery assembly including the same.

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2023-0133561, filed on October 6, 2023, and all contents of the document in that Republic of Korea Patent Application are 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] As secondary batteries become increasingly used in mobility, demand for their safety is increasing. Fires and other accidents involving secondary batteries used in mobility vehicles can endanger the lives of drivers, making research into technologies that enhance secondary battery safety essential.

[0005] The technical problem to be solved by the present invention is to provide a battery cell and a battery assembly including the same.

[0006] In order to solve the above-described problem, the technical idea of ​​the present invention provides a battery cell including: an electrode assembly; a cover sheet including a main body portion surrounding the electrode assembly and a sealing joint portion extending in a first direction from one side of the main body portion; and a first multifunctional terminal block (MTB) located at one end of the electrode assembly and including a first housing connected to the main body portion of the cover sheet; wherein a width of the sealing joint portion at a center of the sealing joint portion is smaller than a width of the sealing joint portion at an edge of the sealing joint portion.

[0007] In exemplary embodiments, the sealing joint is further characterized by including a fixing tape for fixing the edge portion to the main body portion.

[0008] In exemplary embodiments, the cover sheet further comprises an elastic band that adheres the edge portion and the main body portion to the first housing.

[0009] In exemplary embodiments, the main body portion of the cover sheet is characterized in that it is attached to the first housing.

[0010] In exemplary embodiments, the sealing joint is characterized in that the first portion and the second portion of the cover sheet are joined to each other.

[0011] In exemplary embodiments, the sealing joint comprises a first edge connected to the body portion and a second edge opposite the first edge, wherein a profile of the second edge of the sealing joint comprises a plurality of straight lines.

[0012] In exemplary embodiments, the sealing joint comprises a first edge connected to the body portion and a second edge opposite the first edge, wherein the profile of the second edge of the sealing joint comprises a curve.

[0013] In exemplary embodiments, at the edge portion of the sealing joint, the width of the sealing joint is characterized in that it decreases as it moves away from the end portion of the sealing joint along the first direction.

[0014] In exemplary embodiments, the sealing joint is characterized in that the width of the sealing joint is uniform at the center of the sealing joint.

[0015] In exemplary embodiments, the first MTB is characterized by further comprising an external terminal mounted to the first housing and connected to an electrode lead of the electrode assembly.

[0016] In exemplary embodiments, the first MTB further comprises a rupture disk mounted on the first housing, the venting disk being configured to rupture and release gas when the internal pressure of the battery cell increases.

[0017] In exemplary embodiments, the first MTB further comprises a check valve mounted on the first housing, the check valve being configured to open to discharge internal gas when the internal pressure of the battery cell is higher than a reference pressure, and to close again after the internal pressure is relieved.

[0018] In exemplary embodiments, the invention further comprises a second MTB spaced apart from the first MTB in the first direction with the electrode assembly interposed therebetween, the second MTB comprising a second housing connected to the main body portion of the cover sheet.

[0019] In order to solve the above-described problem, the technical idea of ​​the present invention provides a battery assembly including: a plurality of battery cells; and a cooling pad disposed between the plurality of battery cells; wherein each of the plurality of battery cells includes: an electrode assembly; a cover sheet including a main body portion surrounding the electrode assembly and a sealing joint portion connected to the main body portion and extending in a first direction; and a multifunctional terminal block (MTB) located at one end of the electrode assembly and including a housing connected to the main body portion of the cover sheet; wherein a width of the sealing joint portion at a center portion of the sealing joint portion is smaller than a width of the sealing joint portion at an edge portion of the sealing joint portion.

[0020] In exemplary embodiments, the body portion of the cover sheet includes an upper portion covering an upper surface of the electrode assembly and a side portion covering a side surface of the electrode assembly, the cooling pad is in contact with the side portion of the body portion of the cover sheet, and the sealing joint is connected to the upper portion of the body portion of the cover sheet.

[0021] According to exemplary embodiments of the present invention, since the sealing joint of a battery cell has a minimum width at its center, when the internal pressure of the battery cell increases, the seal is first broken at the center of the sealing joint, and high-temperature gas or flame generated inside the battery cell can be released upward through the center of the sealed joint where the seal is broken. Accordingly, heat transmission between adjacent battery cells can be prevented, and ultimately, the safety of a battery assembly including the battery cell can be improved.

[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] FIG. 1 is a perspective view showing a battery cell according to exemplary embodiments of the present invention.

[0024] Figure 2 is an exploded perspective view showing the battery cell of Figure 1.

[0025] Fig. 3 is a cross-sectional view showing a part of the battery cell of Fig. 1.

[0026] Figure 4 is a plan view showing a portion of a battery cell.

[0027] Figures 5a to 5c are perspective views showing a method for manufacturing a battery cell.

[0028] FIG. 6 is a plan view showing a portion of a battery cell according to exemplary embodiments of the present invention.

[0029] FIG. 7 is a plan view illustrating a portion of a battery cell according to exemplary embodiments of the present invention.

[0030] FIG. 8 is a perspective view showing a battery assembly according to exemplary embodiments of the invention.

[0031] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0032] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0033] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0034] Since the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes or proportions.

[0035]

[0036] Fig. 1 is a perspective view illustrating a battery cell (100) according to exemplary embodiments of the present invention. Fig. 2 is an exploded perspective view illustrating the battery cell (100) of Fig. 1. Fig. 3 is a cross-sectional view illustrating a portion of the battery cell (100) of Fig. 1.

[0037] Referring to FIGS. 1 to 3, a battery cell (100) may include an electrode assembly (110), multifunctional terminal blocks (MTB) (120), and a cover sheet (130).

[0038] The electrode assembly (110) may include a plurality of unit cells (111). Each of the plurality of unit cells (111) may have an electrode material applied to a metal foil that acts as a current collector. In exemplary embodiments, the electrode assembly (110) is a stacked electrode assembly, and the plurality of unit cells (111) may be stacked on each other in a second direction (e.g., an X-direction). The electrode assembly (110) composed of the plurality of unit cells (111) may have a generally rectangular parallelepiped shape. The electrode assembly (110) may have first and second sides that are opposite in the second direction (e.g., an X-direction), and upper and lower surfaces that are opposite in a third direction (e.g., a Z-direction).

[0039] Each unit cell (111) may have a thin plate-shaped body extending in a first direction (e.g., Y direction). Each unit cell (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. The positive electrode unit cells and the negative electrode unit cells may be separated from each other by a separator. In some embodiments, the plurality of unit cells (111) may be formed by alternately stacking a plurality of positive electrode unit cells and a plurality of negative electrode unit cells. The plurality of positive electrode unit cells and the plurality of negative electrode unit cells may be separated from each other by a separator.

[0040] The electrode assembly (110) may have electrode leads (116) at both ends in the first direction (e.g., Y 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).

[0041] In some embodiments, the 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 electrode assembly (110) may be coupled to one of the two electrode leads (116) on one side of the electrode assembly (110) and one of the two electrode leads (116) on the other side of the electrode assembly (110). And, the remaining half of the plurality of unit cells (111) included in the electrode assembly (110) may be coupled to the other of the two electrode leads (116) on one side of the electrode assembly (110) and the other of the two electrode leads (116) on the other side of the electrode assembly (110). However, the present invention is not limited thereto.

[0042] In some embodiments, the electrode assembly (110) may have one or more electrode leads (116) on one side. In some embodiments, the electrode assembly (110) may have one or more electrode leads (116) on the other side.

[0043] An MTB (120) may be arranged at each of both ends along a first direction (e.g., Y direction) of the electrode assembly (110). The MTBs (120) may be spaced apart in the first direction (e.g., Y direction) with the electrode assembly (110) interposed therebetween. For example, a first MTB may be provided at one end of the electrode assembly (110) in the first direction (e.g., Y direction), and a second MTB may be provided at the other end of the electrode assembly (110) in the first direction (e.g., Y direction). In this case, one of the first MTB and the second MTB may be electrically connected to the positive electrode side of the electrode assembly (110), and the other may be electrically connected to the negative electrode side of the electrode assembly (110). The first MTB and the second MTB may have substantially the same or similar configurations, except that they may have different electrical polarities.

[0044] The MTB (120) may include an MTB housing (122), an external terminal (124), a bus bar (125), a rupture disk (126), and a check valve (128) mounted within the MTB housing (122). In the present disclosure, two MTBs (120) may be referred to as a first MTB and a second MTB, and the MTB housing (122) of the first MTB may be referred to as a first MTB housing, and the MTB housing (122) of the second MTB may be referred to as a second MTB housing.

[0045] The MTB housing (122) may be made of a material having relatively high rigidity, such as metal, and may define the appearance of the MTB (120). In some embodiments, the MTB housing (122) 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.

[0046] The above MTB housing (122) may include a through hole for exposing the external terminal (124) to the outside. The through hole of the MTB housing (122) may be provided in the MTB housing (122) so that the external terminal (124) is exposed to the outside in the first direction (e.g., Y direction). The shape of the through hole may be configured to match the outer shape of the portion where the external terminal (124) is exposed to the outside.

[0047] The external terminal (124) is accommodated within the MTB housing (122) and can be inserted and mounted into a through hole of the MTB housing (122). The external terminal (124) 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.

[0048] In some embodiments, the exposed surface of the external terminal (124) facing outward from the MTB housing (122) may be a plane. In some embodiments, the exposed surface of the external terminal (124) may have a plane extending perpendicular to the first direction (e.g., Y direction).

[0049] In some embodiments, an electrically insulating spacer may be provided between the external terminal (124) and the MTB housing (122) so that the external terminal (124) is electrically insulated from the MTB housing (122).

[0050] The venting disc (126) may be mounted in a through hole provided in the MTB housing (122). The venting disc (126) may be configured to rupture when the internal pressure of the battery cell (100) excessively increases, thereby releasing gas that causes the excessively increased internal pressure. The venting disc (126) may not be restored to its original state if it ruptures due to a thermal event occurring inside the battery cell (100). The venting disc (126) may be inserted and mounted in the through hole of the MTB housing (122). The venting disc (126) may be any venting disc (126) known in the art and is not particularly limited. The venting disc (126) may be provided in at least one of the two MTBs (120) located at both ends of the battery cell (100).

[0051] The check valve (128) may be mounted in a through-hole provided in the MTB housing (122). The check valve (128) may be configured to open and close a gas discharge passage depending on the internal pressure of the battery cell (100). The check valve (128) may be configured to open the gas discharge passage to discharge internal gas when the internal pressure of the battery cell (100) becomes higher than a reference pressure, and to close the gas discharge passage again when the internal pressure is relieved by the discharge of the gas. The check valve (128) may close the gas discharge passage to block gas discharge when the internal pressure of the battery cell (100) becomes lower than the reference pressure. The check valve (128) may be inserted and mounted in the through-hole of the MTB housing (122). Since the check valve (128) 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. The above check valve (128) may be provided in at least one of the two MTBs (120) at both ends of the battery cell (100).

[0052] In some embodiments, the MTB (120) may include an electrolyte injection port (127) into which an electrolyte may be injected. The electrolyte injection port (127) may be provided in the MTB housing (122). In some embodiments, the electrolyte injection port (127) may be provided in only one of the two MTBs (120) at both ends of the battery cell (100). The electrolyte injected through the electrolyte injection port (127) may be an electrolyte used for a typical lithium secondary battery, and is not particularly limited.

[0053] The bus bar (125) can electrically connect the external terminal (124) to the electrode lead (116) of the electrode assembly (110). The bus bar (125) can be mounted within the MTB housing (122).

[0054] A bus bar (125) may be provided to make surface contact with an external terminal (124). The bus bar (125) may be made of a metal material having low electrical resistance. In some embodiments, the bus bar (125) 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.

[0055] In exemplary embodiments, the material of the bus bar (125) and the material of the external terminal (124) may be different from each other. In some embodiments, the bus bar (125) may include copper, and the external terminal (124) may include aluminum. In some exemplary embodiments, the material of the bus bar (125) and the material of the external terminal (124) may be the same.

[0056] The above bus bar (125) may be configured to make surface contact with the electrode lead (116) of the electrode assembly (110). In some embodiments, the bus bar (125) may be joined to the electrode lead (116) by welding.

[0057] In some embodiments, the bus bar (125) may include a center portion (125c) in a flat shape extending generally along a second direction (e.g., X direction) and a third direction (e.g., Z direction), and an edge portion (125e) bent and extended from the center portion (125c). The center portion (125c) may be in contact with an external terminal (124), and the edge portion (125e) may be in contact with an electrode lead (116) of an electrode assembly (110).

[0058] The bus bar (125) may include two edge portions (125e) facing each other in a second direction (e.g., X direction), and the two edge portions (125e) may have a flat plate shape extending generally along a first direction (e.g., Y direction) and a third direction (e.g., Z direction), respectively. One of the two edge portions (125e) may extend in the first direction (e.g., Y direction) from one end of the center portion (125c) along the second direction (e.g., X direction), and the other of the two edge portions (125e) may extend in the first direction (e.g., Y direction) from the other end of the center portion (125c) along the second direction (e.g., X direction). The center portion (125c) and the two edge portions (125e) may be configured together to form a U-shaped cross-sectional shape. When the two edge portions (125e) are referred to as the first edge portion and the second edge portion, the outer surface of the first edge portion may have a plane that makes surface contact with the first electrode lead of the electrode assembly (110), and the outer surface of the second edge portion may have a plane that makes surface contact with the second electrode lead of the electrode assembly (110).

[0059] In some embodiments, the electrode lead (116) may include a pre-bended portion that is bent at a portion that does not contact the bus bar (125). The pre-bended portion may prevent stress from being concentrated at a specific portion of the electrode lead (116) due to an external force applied to the electrode assembly (110), thereby improving safety.

[0060] The cover sheet (130) may provide a receiving space for receiving the electrode assembly (110). The cover sheet (130) may include a main body (131) surrounding the electrode assembly (110) and a sealing joint (133) extending or protruding from the main body (131).

[0061] The main body (131) of the cover sheet (130) can surround the electrode assembly (110) to form a receiving space in which the electrode assembly (110) is received. The main body (131) of the cover sheet (130) can be connected to the MTB housings (122) of the MTBs (120). For example, a first edge of the main body (131) of the cover sheet (130) can be attached to a first housing of a first MTB, and a second edge of the main body (131) of the cover sheet (130) can be attached to a second housing of a second MTB. The first edge of the main body (131) of the cover sheet (130) can be in continuous contact along the periphery of the first housing of the first MTB, and the second edge of the main body (131) of the cover sheet (130) can be in continuous contact along the periphery of the second housing of the second MTB. The main body (131) of the cover sheet (130) may include a first side facing the first side of the electrode assembly (110) and the first side surfaces of the two MTB housings (122), a second side facing the second side of the electrode assembly (110) and the second side surfaces of the two MTB housings (122), an upper side facing the upper surface of the electrode assembly (110) and the upper surfaces of the two MTB housings (122), and a lower side facing the lower surface of the electrode assembly (110) and the lower surfaces of the two MTB housings (122). The main body (131) of the cover sheet (130) may form a space for accommodating a battery cell (100) in which the electrode assembly (110) is accommodated together with the MTB housings (122) of the two MTBs (120).

[0062] The above sealing joint (133) can seal the accommodation space of the main body (131) in which the electrode assembly (110) is accommodated. The sealing joint (133) is connected to the upper portion of the main body (131) and can extend in a first direction (e.g., Y direction). The sealing joint (133) can be a joint in which a first part (138) and a second part (139) of a cover sheet (130) are joined. For example, in order to manufacture the cover sheet (130), after surrounding the electrode assembly (110) with a single cover sheet (130), the first part (138) and the second part (139) of the cover sheet (130) can be joined to form the sealing joint (133).

[0063] In exemplary embodiments, the cover sheet (130) may be a laminate sheet comprising one or more resin layers and one or more metal layers. The one or more resin layers and the one or more metal layers may be laminated to each other.

[0064] According to exemplary embodiments of the present invention, since the battery cell (100) accommodates all of the units having respective functions within the MTB (120), such as an external terminal (124), a venting disk (126), a check valve (128), an electrolyte injection port (127), a bus bar (125), etc., the battery cell (100) itself has functions equivalent to a general battery module. Therefore, the battery cell (100) according to the embodiments can have a high degree of freedom and compatibility, and is advantageous for implementing cell-to-pack.

[0065] Fig. 4 is a plan view showing a part of a battery cell (100).

[0066] Referring to FIG. 4 together with FIG. 1, the width of the sealing joint (133) may vary depending on the position of the sealing joint (133) along the first direction (e.g., Y direction). The width of the sealing joint (133) may refer to the length of the sealing joint (133) along the direction perpendicular to the first direction (e.g., Y direction). Alternatively, when the sealing joint (133) has a first edge (1331) connected to the main body (131) and a second edge (1333) opposite to the first edge (1331), the width of the sealing joint (133) may refer to the distance between the first edge (1331) and the second edge (1333) of the sealing joint (133). The first edge (1331) of the sealing joint (133) is a boundary between the sealing joint (133) and the main body (131), and can extend in a first direction (e.g., Y direction) from one end of the main body (131) to the other end.

[0067] In exemplary embodiments, when the sealing joint (133) has a minimum width (W1) at a first point, the first point of the sealing joint (133) may be within a center portion (133c) of the sealing joint (133). In exemplary embodiments, the sealing joint (133) may have a maximum width (W2) at an end along the first direction (e.g., the Y direction). In exemplary embodiments, the width of the sealing joint (133) may increase as it moves away from the first point.

[0068] In exemplary embodiments, the profile of the second edge (1333) of the sealing joint (133) may include a plurality of straight lines, for example, two straight lines.

[0069] In exemplary embodiments, the minimum width (W1) of the sealing joint (133) may be between 10% and 90%, between 15% and 85%, between 20% and 80%, between 25% and 75%, or between 30% and 70% of the maximum width (W2) of the sealing joint (133). In exemplary embodiments, the minimum width (W1) of the sealing joint (133) may be 3 mm or greater. In exemplary embodiments, the maximum width (W2) of the sealing joint (133) may be less than or equal to the width of the upper portion of the main body (131) in the second direction (e.g., the X direction) or the width of the MTB housing (122) in the second direction (e.g., the X direction).

[0070] In exemplary embodiments, the sealing joint (133) may include two edge portions (133e) and a center portion (133c) between the two edge portions (133e) in a first direction (e.g., Y direction). In the sealing joint (133), the length of each edge portion (133e) in the first direction (e.g., Y direction) may be between 10% and 40%, between 15% and 35%, or between 20% and 30% of the total length of the sealing joint (133) in the first direction (e.g., Y direction). In this case, the width of the center portion (133c) of the sealing joint (133) may be smaller than the width of the edge portions (133e) of the sealing joint (133).

[0071] In exemplary embodiments, within the edge portion (133e) of the sealing joint (133), the width of the sealing joint (133) may decrease as it moves away from the end portion along the first direction (e.g., Y direction) of the sealing joint (133).

[0072] In exemplary embodiments, the battery cell (100) may include fixing tapes (141) for fixing edge portions (133e) of the sealing joint (133) to the body portion (131). Each fixing tape (141) may fix a corresponding edge portion (133e) of the sealing joint (133) to the body portion (131). A portion of each fixing tape (141) may be attached to the edge portion (133e) of the sealing joint (133), and another portion of each fixing tape (141) may be attached to the body portion (131).

[0073] In exemplary embodiments, the battery cell (100) may include elastic bands (145) for tightly securing the cover sheet (130) to the MTB housings (122). Each elastic band (145) may secure a corresponding edge portion (133e) of the sealing joint (133) and the main body portion (131) to the corresponding MTB housing (122). Each elastic band (145) may have a ring shape extending to surround the MTB housing (122).

[0074] In the sealing joint (133) of the cover sheet (130), the sealing strength of the sealing joint (133) in each area may be proportional to the width of the sealing joint (133) in that area. In embodiments, the sealing joint (133) has a minimum width at its center (133c), so that when the internal pressure of the battery cell (100) rises, the seal is first broken at the center (133c) of the sealing joint (133), and high-temperature gas or flame generated inside the battery cell (100) may be released upward through the center (133c) of the sealing joint (133) where the seal is broken. According to the present invention, high-temperature gas or flame generated inside a battery cell (100) is intensively discharged through the center (133c) of the sealing joint (133) of the cover sheet (130), so that heat transmission between adjacent battery cells (100) can be prevented, and ultimately, the safety of a battery assembly including a battery cell (100) can be improved.

[0075]

[0076] Figures 5a to 5c are perspective views showing a method of manufacturing a battery cell (100).

[0077] Referring to FIG. 5A, a cover sheet (130) is formed that is attached to the MTB housings (122) of two MTBs (120). For example, a single sheet may be attached along the perimeter of the MTB housings (122) of the two MTBs (120), and a first portion and a second portion of the single sheet may be joined. Thereafter, a portion of the joint where the first portion and the second portion of the single sheet are joined may be removed, thereby forming a cover sheet (130) having a sealing joint (133) having a variable width.

[0078] Referring to Fig. 5b, the edge of the cover sheet (130) is tightly fixed to the periphery of the MTB housing (122) using an elastic band (145). By means of the elastic band (145), the sealing joint (133) can be tightly fixed to the outer surface of the main body (131).

[0079] Referring to Fig. 5c, the edge portion of the sealing joint (133) is fixed to the main body (131) using the fixing tape (141). By the fixing tape (141), the two edge portions of the sealing joint (133) can be fixed to the outer surface of the main body (131).

[0080]

[0081] FIGS. 6 and 7 are plan views each showing a portion of a battery cell according to exemplary embodiments of the present invention. Below, the battery cells illustrated in FIGS. 6 and 7 will be described, focusing on differences from the battery cell (100) described with reference to FIGS. 1 to 4.

[0082] Referring to FIG. 6, the profile of the second edge (1333) of the sealing joint (133) may at least partially include a curve. When the sealing joint (133) has a minimum width (W1) at a first point within its center (133c), the width of the sealing joint (133) may increase as it moves away from the first point.

[0083] Referring to Fig. 7, at the center (133c) of the sealing joint (133), the width of the sealing joint (133) may be constant. And, at the edge (133e) of the sealing joint (133), the width of the sealing joint (133) may increase as it moves away from the center (133c) of the sealing joint (133).

[0084]

[0085] FIG. 8 is a perspective view showing a battery assembly (10) according to exemplary embodiments of the invention.

[0086] Referring to FIG. 8, a battery assembly (10) may include a plurality of battery cells (100) and a plurality of cooling pads (200). The plurality of battery cells (100) may be arranged in a second direction (e.g., X direction), and a cooling pad (200) may be placed between two adjacent battery cells (100).

[0087] A cooling pad (200) may be placed between two battery cells (100) adjacent in a first direction (e.g., Y direction). The two battery cells (100) may be spaced apart in the first direction (e.g., Y direction) by the cooling pad (200). The cooling pad (200) may be attached to a side of a main body (131) of a cover sheet (130) of an adjacent battery cell (100) and / or to an MTB housing (122).

[0088] The cooling pad (200) may be configured to cool adjacent battery cells (100). In some embodiments, the cooling pad (200) may be configured to cool the battery cells (100) by absorbing heat of the adjacent battery cells (100). For example, the cooling pad (200) may include an endothermic material layer therein. For example, the endothermic material layer of the cooling pad (200) may include an absorbent member such as a super absorbent polymer (SAP). The cooling pad (200) is disposed between adjacent battery cells (100) in a first direction (e.g., Y direction) and may function as a thermal barrier to thermally isolate the battery cells (100). Since a cooling pad (200) is placed between a plurality of battery cells (100), even if one of the plurality of battery cells (100) ignites, heat transfer between the ignited battery cell (100) and another battery cell (100) can be blocked or suppressed by the cooling pad (200).

[0089] In addition, the cooling pad (200) is configured to have a predetermined rigidity by the internal support structure and / or the internal filler, so as to prevent or suppress deformation of the battery cell (100) due to swelling. Furthermore, the cooling pad (200) is configured to have a predetermined elasticity by the internal support structure and / or the internal filler, and can be configured to elastically deform in a first direction (e.g., Y direction) which is the arrangement direction of the battery cells (100). By elastically deforming in the first direction (e.g., Y direction), the cooling pad (200) can function as a buffer pad against deformation of the battery cell (100) (e.g., deformation of the battery cell (100) due to swelling).

[0090] According to exemplary embodiments of the present invention, a cooling pad (200) that functions as a thermal barrier and buffer is disposed between adjacent battery cells (100), thereby preventing heat transfer between the battery cells (100) and improving the structural safety of the battery cells (100). Accordingly, the safety and reliability of a battery assembly (10) including battery cells (100) can be improved.

[0091] According to exemplary embodiments of the present invention, both sides of each battery cell (100) may be in contact with a cooling pad (200), and the lower portion of each battery cell (100) may be in contact with an external heat sink. In this case, high-temperature gas or flame generated in each battery cell (100) may be discharged upward through the center portion (133c) of the sealing joint (133) having a relatively small sealing strength. According to the present invention, high-temperature gas or flame generated inside the battery cell (100) is intensively discharged through the center portion (133c) of the sealing joint (133) of the cover sheet (130), so that heat transmission between adjacent battery cells (100) can be prevented, and ultimately, the safety of the battery assembly (10) including the battery cell (100) can be improved.

[0092]

[0093] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

Claims

1. Electrode assembly; A cover sheet including a main body portion surrounding the electrode assembly and a sealing joint portion extending in a first direction from one side of the main body portion; and A first multifunctional terminal block (MTB) located at one end of the electrode assembly and including a first housing connected to the main body portion of the cover sheet; Including, A battery cell, wherein the width of the sealing joint at the center of the sealing joint is smaller than the width of the sealing joint at the edge of the sealing joint.

2. In paragraph 1, A battery cell characterized in that it further includes a fixing tape that fixes the edge portion of the sealing joint to the main body portion.

3. In paragraph 1, A battery cell further comprising an elastic band that adheres the edge portion of the sealing joint and the main body portion of the cover sheet to the first housing.

4. In paragraph 1, A battery cell characterized in that the main body portion of the cover sheet is attached to the first housing.

5. In paragraph 1, A battery cell characterized in that the above sealing joint is a joint in which the first part and the second part of the cover sheet are joined to each other.

6. In paragraph 1, The sealing joint includes a first edge connected to the main body and a second edge opposite to the first edge, A battery cell characterized in that the profile of the second edge of the sealing joint includes a plurality of straight lines.

7. In paragraph 1, The sealing joint includes a first edge connected to the main body and a second edge opposite to the first edge, A battery cell characterized in that the profile of the second edge of the sealing joint comprises a curve.

8. In paragraph 1, A battery cell characterized in that, at the edge portion of the sealing joint, the width of the sealing joint decreases as it moves away from the end portion of the sealing joint along the first direction.

9. In paragraph 1, A battery cell characterized in that the width of the sealing joint is uniform at the center of the sealing joint.

10. In paragraph 1, A battery cell characterized in that the first MTB further includes an external terminal mounted in the first housing and connected to an electrode lead of the electrode assembly.

11. In paragraph 1, A battery cell characterized in that the first MTB further includes a rupture disk mounted on the first housing, and the venting disk is configured to rupture and discharge gas when the internal pressure of the battery cell increases.

12. In paragraph 1, The above first MTB further comprises a check valve mounted on the first housing, A battery cell characterized in that the check valve is configured to open to discharge internal gas when the internal pressure of the battery cell is higher than a reference pressure, and to close again after the internal pressure is relieved.

13. In paragraph 1, A battery cell further comprising a second MTB spaced apart from the first MTB in the first direction with the electrode assembly interposed therebetween, characterized in that the second MTB includes a second housing connected to the main body portion of the cover sheet.

14. Multiple battery cells; and A cooling pad disposed between the plurality of battery cells; Each of the above plurality of battery cells, electrode assembly; A cover sheet including a main body portion surrounding the electrode assembly and a sealing joint portion connected to the main body portion and extending in a first direction; and A multifunctional terminal block (MTB) having a housing at one end of the electrode assembly and connected to the main body of the cover sheet; Including, A battery assembly, wherein the width of the sealing joint at the center of the sealing joint is smaller than the width of the sealing joint at the edge of the sealing joint.

15. In paragraph 14, The main body portion of the cover sheet includes an upper portion covering the upper surface of the electrode assembly and a side portion covering the side surface of the electrode assembly, The above cooling pad is in contact with the side of the main body of the above cover sheet, A battery assembly characterized in that the sealing joint is connected to the upper portion of the main body of the cover sheet.

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