Battery cells and battery assemblies including battery cells

Abstract

The technical idea of ​​the present invention provides a battery cell including an electrode assembly, a cover sheet including a main body surrounding the electrode assembly and a sealing joint extending in a first direction from one side of the main body, and a first multi-function terminal block located at one end of the electrode assembly and including a first housing connected to the main body of the cover sheet, 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.

Description

Technical Field

[0001] (Technical Field) The present invention relates to a battery cell and a battery assembly including the battery cell.

[0002] (Reference to Related Applications) This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0133561 filed on October 6, 2023, and all the contents disclosed in the literature of the Korean patent application are included as part of this specification.

Background Art

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as an energy source for various wireless devices such as mobile phones, notebook computers, and wireless vacuum cleaners. In recent years, due to the improvement of energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has decreased epochally, and as the driving range of battery electric vehicles (BEVs) increases to a level equivalent to that of fuel vehicles, the main application of secondary batteries has shifted from mobile devices to mobility.

[0004] As secondary batteries are used in mobility, the requirements for the safety of secondary batteries are increasing. When an accident such as a fire occurs in a secondary battery used for mobility, it can endanger the life of the driver, so research on technologies to improve the safety of secondary batteries is essential.

Summary of the Invention

Problems to be Solved by the Invention

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

Means for Solving the Problems

[0006] To solve the above-mentioned problems, the technical concept of the present invention provides a battery cell comprising: an electrode assembly; a cover sheet including a main body surrounding the electrode assembly and a sealing joint extending in a first direction from one side of the main body; and a first multifunctional terminal block (MTB) located at one end of the electrode assembly and connected to the main body of the cover sheet, 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.

[0007] In an exemplary embodiment, the present invention further includes a fixing tape for securing the edge of the sealing joint to the main body.

[0008] In an exemplary embodiment, the present invention further includes an elastic band that securely fastens the edges and main body of the cover sheet to the first housing.

[0009] In an exemplary embodiment, the main body of the cover sheet is attached to the first housing.

[0010] In an exemplary embodiment, the sealing joint is characterized by being a joint formed by joining a first portion and a second portion of a cover sheet together.

[0011] In an exemplary embodiment, the sealing joint includes a first edge connected to the main body and a second edge opposite to the first edge, and the profile of the second edge of the sealing joint is characterized by including a plurality of straight lines.

[0012] In an exemplary embodiment, the sealing joint includes a first edge connected to the main body and a second edge opposite to the first edge, and the profile of the second edge of the sealing joint is characterized by including a curve.

[0013] In an exemplary embodiment, the width of the sealing joint decreases as it moves away from the end of the sealing joint along the first direction.

[0014] In an exemplary embodiment, the width of the sealing joint is uniform in the central part of the sealing joint.

[0015] In an exemplary embodiment, the first MTB is further characterized by including external terminals mounted on the first housing and connected to the electrode leads of the electrode assembly.

[0016] In an exemplary embodiment, the first MTB further includes a rupture disk mounted in the first housing, the rupture disk being configured to rupture and release gas when the internal pressure of the battery cell increases.

[0017] In an exemplary embodiment, the first MTB further includes a check valve mounted in the first housing, the check valve being configured to open to release internal gas when the internal pressure of the battery cell is higher than a reference pressure, and to close again after the internal pressure has been relieved.

[0018] In exemplary embodiments, the system further includes a second MTB spaced apart from the first MTB in a first direction, with the electrode assembly in between, the second MTB being characterized by including a second housing connected to the main body of the cover sheet.

[0019] To solve the above-mentioned problems, the technical concept of the present invention provides a battery assembly comprising a plurality of battery cells and a cooling pad disposed between the plurality of battery cells, wherein each of the plurality of battery cells comprises an electrode assembly, a cover sheet including a main body surrounding the electrode assembly and a sealing joint connected to the main body and extending in a first direction, and a multifunctional terminal block (MTB) located at one end of the electrode assembly and connected to the main body of the cover sheet, 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.

[0020] In an exemplary embodiment, the main body of the cover sheet includes an upper portion that covers the upper surface of the electrode assembly and a side portion that covers the side surface of the electrode assembly, the cooling pad contacts the side portion of the main body of the cover sheet, and the hermetic joint is connected to the upper portion of the main body of the cover sheet.

Advantages of the Invention

[0021] According to an exemplary embodiment of the present invention, since the hermetic joint of the battery cell has a minimum width at its central portion, when the internal pressure of the battery cell increases, the seal is first broken at the central portion of the hermetic joint, and the high-temperature gas or flame generated inside the battery cell can be discharged upward through the central portion of the hermetic joint where the seal has been broken. Thereby, heat transfer between adjacent battery cells can be prevented, and ultimately, the safety of the battery assembly including the battery cells can be improved.

[0022] The effects obtainable 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 having ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following description. That is, unintended effects associated with implementing the exemplary embodiments of the present disclosure can also be derived by those having ordinary knowledge in the technical field from the exemplary embodiments of the present disclosure.

Brief Description of the Drawings

[0023] [Figure 1] It is a perspective view showing a battery cell according to an exemplary embodiment of the present invention. [Figure 2] It is an exploded perspective view showing the battery cell of FIG. 1. [Figure 3] It is a cross-sectional view showing a part of the battery cell of FIG. 1. [Figure 4] It is a plan view showing a part of the battery cell. [Figure 5a] It is a perspective view showing a method of manufacturing a battery cell. [Figure 5b] It is a perspective view showing a method of manufacturing a battery cell. [Figure 5c] It is a perspective view showing a method of manufacturing a battery cell. [Figure 6] It is a plan view showing a part of a battery cell according to an exemplary embodiment of the present invention. [Figure 7] It is a plan view showing a part of a battery cell according to an exemplary embodiment of the present invention. [Figure 8] It is a perspective view showing a battery assembly according to an exemplary embodiment of the present invention.

Mode for Carrying Out the Invention

[0024] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in this specification and the claims are not to be construed as being limited to their ordinary or dictionary meanings, but rather should be construed as meanings and concepts consistent with the technical idea of the present invention based on the principle that the inventor can appropriately define the concept of the terms in order to best explain his own invention.

[0025] Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention. Thus, there can be various equivalents and modifications that can replace these at the time of this application.

[0026] Also, in the description of the present invention, when 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 thereof will be omitted.

[0027] The embodiments of the present invention are provided to more fully explain the present invention to an ordinary technician. Therefore, the shapes and sizes of the components in the drawings can be exaggerated, omitted, or shown schematically for a clearer explanation. Thus, the sizes and ratios of each component do not fully reflect the actual sizes and ratios.

[0028] Figure 1 is a perspective view showing a battery cell 100 according to an exemplary embodiment of the present invention. Figure 2 is an exploded perspective view showing the battery cell 100 of Figure 1. Figure 3 is a cross-sectional view showing a part of the battery cell 100 of Figure 1.

[0029] Referring to Figures 1 to 3, the battery cell 100 may include an electrode assembly 110, a multifunctional terminal block (MTB) 120, and a cover sheet 130.

[0030] The electrode assembly 110 may include a plurality of unit cells 111. Each of the unit cells 111 may have an electrode material coated on 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 can be stacked on top of each other in a second direction (e.g., the X direction). The electrode assembly 110, composed of a plurality of unit cells 111, may generally have a rectangular parallelepiped shape. The electrode assembly 110 may have first and second sides opposite in the second direction (e.g., the X direction) and top and bottom surfaces opposite in a third direction (e.g., the Z direction).

[0031] Each unit battery 111 may have a thin, plate-shaped body extending in a first direction (for example, the Y direction). Each unit battery 111 may be a positive electrode unit battery or a negative electrode unit battery. In some embodiments, the plurality of unit batteries 111 may be arranged in alternating stacks of positive electrode unit batteries and negative electrode unit batteries. The positive electrode unit batteries and the negative electrode unit batteries can be separated from each other by a separator membrane. In some embodiments, the plurality of unit batteries 111 may be arranged in alternating stacks of positive electrode unit batteries and negative electrode unit batteries. The plurality of positive electrode unit batteries and the plurality of negative electrode unit batteries can be separated from each other by a separator membrane.

[0032] The electrode assembly 110 may have electrode leads 116 at both ends in the first direction (for example, the Y direction). The electrode leads 116 can be electrically connected to the electrode tabs of the plurality of unit batteries 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.

[0033] 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 batteries 111 included in the electrode assembly 110 can be coupled to one of the two electrode leads 116 on one side of the electrode assembly 110 and to one of the two electrode leads 116 on the other side of the electrode assembly 110. The remaining half of the plurality of unit batteries 111 included in the electrode assembly 110 can be coupled to the other of the two electrode leads 116 on one side of the electrode assembly 110 and to 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.

[0034] 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.

[0035] MTBs 120 can be positioned at each of the two ends of the electrode assembly 110 along a first direction (e.g., the Y direction). The MTBs 120 can be spaced apart in the first direction (e.g., the Y direction) with the electrode assembly 110 in between. For example, a first MTB can be provided at one end of the electrode assembly 110 in the first direction (e.g., the Y direction), and a second MTB can be provided at the other end of the electrode assembly 110 in the first direction (e.g., the Y direction). In this case, one of the first and second MTBs can be electrically connected to the positive electrode side of the electrode assembly 110, and the other can be electrically connected to the negative electrode side of the electrode assembly 110. The first and second MTBs may have substantially the same or similar configurations, differing only in their electrical polarity.

[0036] The MTB120 may include an MTB housing 122, external terminals 124 mounted within the MTB housing 122, a busbar 125, a rupture disk 126, and a check valve 128. In this disclosure, two MTBs 120 may be referred to as the first MTB and the second MTB, the MTB housing 122 of the first MTB may be referred to as the first MTB housing, and the MTB housing 122 of the second MTB may be referred to as the second MTB housing.

[0037] The MTB housing 122 can be made of a material having relatively high rigidity, such as metal, and can define the appearance of the MTB 120. In some embodiments, the MTB housing 122 can be made of aluminum (Al), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), manganese (Mn), or an alloy containing one or more of these.

[0038] The MTB housing 122 may include a through-hole for exposing an external terminal 124 to the outside. The through-hole in the MTB housing 122 may be provided such that the external terminal 124 is exposed to the outside in the first direction (e.g., the Y direction). The form of the through-hole may be configured to match the outer edge shape of the portion in which the external terminal 124 is exposed to the outside.

[0039] The external terminal 124 is housed within the MTB housing 122 and can be inserted into and mounted in a through-hole of the MTB housing 122. The external terminal 124 can be made of a metal or metal alloy with low electrical resistance, such as copper (Cu), aluminum (Al), nickel (Ni), iron (Fe), platinum (Pt), manganese (Mn), or an alloy containing one or more of these.

[0040] In some embodiments, the exposed surface of the external terminal 124 that is exposed to the outside from the MTB housing 122 may be a plane. In some embodiments, the exposed surface of the external terminal 124 may have a plane that extends perpendicularly to the first direction (e.g., the Y direction).

[0041] In some embodiments, an electrically insulating spacer can be provided between the external terminal 124 and the MTB housing 122 so that the external terminal 124 is electrically isolated from the MTB housing 122.

[0042] The venting disc 126 can be fitted into a through-hole provided in the MTB housing 122. The venting disc 126 can be configured to vent gases causing an excessive rise in internal pressure in the battery cell 100 by rupturing if the internal pressure rises excessively. Once the venting disc 126 ruptures due to a thermal event occurring inside the battery cell 100, it will not be restored to its original state. The venting disc 126 can be inserted into and fitted into a through-hole in the MTB housing 122. The venting disc 126 can be any venting disc 126 known in the art and is not particularly limited. The venting disc 126 can be provided in at least one of the two MTBs 120 located at both ends of the battery cell 100.

[0043] The check valve 128 can be fitted into a through-hole provided in the MTB housing 122. The check valve 128 can be configured to open and close a gas vent passage in response to the internal pressure of the battery cell 100. The check valve 128 can be configured to open the gas vent passage to release internal gas when the internal pressure of the battery cell 100 exceeds a reference pressure, and to close the gas vent passage again when the internal pressure is relieved by the release of the gas. The check valve 128 can also be configured to close the gas vent passage so as to shut off gas release when the internal pressure of the battery cell 100 falls below the reference pressure. The check valve 128 can be inserted into and fitted into a through-hole in the MTB housing 122. The check valve 128 can be restored to its original state after the internal gas has been released because there is no part that will burst due to the release of the gas. The check valve 128 can be provided in at least one of the two MTBs 120 located at both ends of the battery cell 100.

[0044] In some embodiments, the MTB 120 may include an electrolyte inlet 127 into which an electrolyte can be injected. The electrolyte inlet 127 may be provided in the MTB housing 122. In some embodiments, the electrolyte inlet 127 may be provided in only one of the two MTBs 120 located at both ends of the battery cell 100. The electrolyte injected through the electrolyte inlet 127 may be any electrolyte used for a typical lithium secondary battery, and is not particularly limited.

[0045] The busbar 125 can electrically connect its external terminal 124 to the electrode lead 116 of the electrode assembly 110. The busbar 125 can be mounted inside the MTB housing 122.

[0046] The busbar 125 may be provided to make surface contact with the external terminal 124. The busbar 125 may be made of a metallic material with low electrical resistance. In some embodiments, the busbar 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 containing one or more of these.

[0047] In exemplary embodiments, the material of the busbar 125 and the material of the external terminal 124 may be different from each other. In some embodiments, the busbar 125 may contain copper and the external terminal 124 may contain aluminum. In some exemplary embodiments, the material of the busbar 125 and the material of the external terminal 124 may be the same from each other.

[0048] The busbar 125 can be configured to make surface contact with the electrode lead 116 of the electrode assembly 110. In some embodiments, the busbar 125 can be joined to the electrode lead 116 by welding.

[0049] In some embodiments, the busbar 125 may include a flat central portion 125c that extends generally along a second direction (e.g., the X direction) and a third direction (e.g., the Z direction), and an edge portion 125e that is bent and extended from the central portion 125c. The central 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.

[0050] The busbar 125 may include two edge portions 125e facing each other in a second direction (e.g., the X direction), and the two edge portions 125e may each have a flat shape extending generally along a first direction (e.g., the Y direction) and a third direction (e.g., the Z direction). One of the two edge portions 125e may extend from one end of the center portion 125c along the second direction (e.g., the X direction) in the first direction (e.g., the Y direction), and the other of the two edge portions 125e may extend from the other end of the center portion 125c along the second direction (e.g., the X direction) in the first direction (e.g., the Y direction). The center portion 125c and the two edge portions 125e may both be configured to have a U-shaped cross-section. 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 contact lead of the electrode assembly 110.

[0051] In some embodiments, the electrode lead 116 may include a pre-bended portion that is bent in a way that does not contact the busbar 125. The pre-bended portion can prevent stress from concentrating on a specific part of the electrode lead 116 due to external forces applied to the electrode assembly 110, thereby improving safety.

[0052] The cover sheet 130 can provide a housing space for accommodating the electrode assembly 110. The cover sheet 130 may include a main body portion 131 surrounding the electrode assembly 110 and a sealing joint portion 133 extending from or protruding from the main body portion 131.

[0053] The main body portion 131 of the cover sheet 130 can surround the electrode assembly 110 and form a housing space in which the electrode assembly 110 is housed. The main body portion 131 of the cover sheet 130 can be connected to the MTB housing 122 of the MTB 120. For example, the first edge of the main body portion 131 of the cover sheet 130 can be attached to the first housing of the first MTB, and the second edge of the main body portion 131 of the cover sheet 130 can be attached to the second housing of the second MTB. The first edge of the main body portion 131 of the cover sheet 130 can be continuously contacted along the perimeter of the first housing of the first MTB, and the second edge of the main body portion 131 of the cover sheet 130 can be continuously contacted along the perimeter 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 of the two MTB housings 122, a second side facing the second side of the electrode assembly 110 and the second side of the two MTB housings 122, an upper part facing the top surface of the electrode assembly 110 and the top surfaces of the two MTB housings 122, and a lower part facing the bottom surface of the electrode assembly 110 and the bottom surfaces of the two MTB housings 122. The main body 131 of the cover sheet 130 can form a housing space for the battery cell 100 in which the electrode assembly 110 is housed together with the MTB housings 122 of the two MTBs 120.

[0054] The sealing joint 133 can seal the housing space of the main body 131 in which the electrode assembly 110 is housed. The sealing joint 133 can be connected to the upper part of the main body 131 and can extend in a first direction (for example, the Y direction). The sealing joint 133 may be a joint formed by joining a first portion 138 and a second portion 139 of a cover sheet 130. For example, to manufacture the cover sheet 130, the electrode assembly 110 can be surrounded by a single cover sheet 130, and then the first portion 138 and the second portion 139 of the cover sheet 130 can be joined to form the sealing joint 133.

[0055] 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 one or more metal layers can be laminated together.

[0056] According to an exemplary embodiment of the present invention, the battery cell 100 houses all the units having their respective functions within the MTB 120, such as the external terminals 124, the venting disk 126, the check valve 128, the electrolyte inlet 127, the busbar 125, etc., so that the battery cell 100 itself has the functionality of a general battery module. Therefore, the battery cell 100 according to the embodiment can have a high degree of flexibility and interchangeability, and is advantageous for realizing cell-to-pack.

[0057] Figure 4 is a plan view showing a portion of the battery cell 100.

[0058] Referring to Figure 4 in conjunction with Figure 1, the width of the sealing joint 133 can vary depending on its position along a first direction (e.g., the Y direction). The width of the sealing joint 133 can mean the length of the sealing joint 133 along a direction perpendicular to the first direction (e.g., the 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 can mean 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 the boundary between the sealing joint 133 and the main body 131 and can extend in the first direction (e.g., the Y direction) from one end of the main body 131 to the other.

[0059] In an exemplary embodiment, the first point of the sealing joint 133 may be within the center 133c of the sealing joint 133, when the sealing joint 133 has a minimum width W1 at a first point. In an exemplary embodiment, the sealing joint 133 may have a maximum width W2 at an end along a first direction (e.g., the Y direction). In an exemplary embodiment, the width of the sealing joint 133 may increase as it moves away from the first point.

[0060] 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.

[0061] In exemplary embodiments, the minimum width W1 of the sealing joint 133 may be 10% to 90%, 15% to 85%, 20% to 80%, 25% to 75%, or 30% to 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 more. In exemplary embodiments, the maximum width W2 of the sealing joint 133 may be less than or equal to the width along the second direction (e.g., the X direction) of the upper part of the main body 131 or the width along the second direction (e.g., the X direction) of the MTB housing 122.

[0062] In exemplary embodiments, the sealing joint 133 may include two edges 133e and a central part 133c located between the two edges 133e in a first direction (e.g., the Y direction). In the sealing joint 133, the length of each individual edge 133e in the first direction (e.g., the Y direction) may be 10% to 40%, 15% to 35%, or 20% to 30% of the total length of the sealing joint 133 in the first direction (e.g., the Y direction). In this case, the width of the central part 133c of the sealing joint 133 may be smaller than the width of the edges 133e of the sealing joint 133.

[0063] In exemplary embodiments, within the edge 133e of the sealing joint 133, the width of the sealing joint 133 may decrease as it moves away from the end of the sealing joint 133 along a first direction (e.g., the Y direction).

[0064] In an exemplary embodiment, the battery cell 100 may include fixing tapes 141 for securing the edges 133e of the sealing joint 133 to the main body 131. Each fixing tape 141 can secure the corresponding edges 133e of the sealing joint 133 to the main body 131. A portion of each fixing tape 141 may adhere to the edges 133e of the sealing joint 133, while another portion of each fixing tape 141 may adhere to the main body 131.

[0065] In an exemplary embodiment, the battery cell 100 may include elastic bands 145 for securing the cover sheet 130 tightly to the MTB housing 122. Each elastic band 145 can secure the corresponding edge 133e and body 131 of the sealing joint 133 to the corresponding MTB housing 122. Each elastic band 145 may have a ring shape that extends to surround the MTB housing 122.

[0066] In the sealing joint 133 of the cover sheet 130, the sealing strength of different regions of the sealing joint 133 can be proportional to the width of the sealing joint 133 in that region. In the embodiment, since the sealing joint 133 has its minimum width at its center 133c, 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 the hot gas or flame generated inside the battery cell 100 can be released upward through the center 133c of the sealing joint 133 where the seal was broken. According to the present invention, since the hot gas or flame generated inside the battery cell 100 is concentrated and discharged through the center 133c of the sealing joint 133 of the cover sheet 130, heat propagation between adjacent battery cells 100 can be prevented, and ultimately the safety of the battery assembly including the battery cells 100 can be improved.

[0067] Figures 5a to 5c are perspective views showing the manufacturing method of the battery cell 100.

[0068] Referring to Figure 5a, a cover sheet 130 is formed attached to the MTB housings 122 of two MTBs 120. For example, a single sheet can be attached around the MTB housings 122 of two MTBs 120, and a first portion and a second portion of the single sheet can be joined together. Then, a portion of the joint formed by the joining of the first and second portions of the single sheet can be removed to form a cover sheet 130 having a sealing joint 133 with a variable width.

[0069] Referring to Figure 5b, the elastic band 145 is used to tightly secure the edge of the cover sheet 130 around the MTB housing 122. The elastic band 145 allows the sealing joint 133 to be tightly secured to the outer surface of the main body 131.

[0070] Referring to Figure 5c, the edges of the sealing joint 133 are fixed to the main body 131 using the fixing tape 141. The two edges of the sealing joint 133 can be fixed to the outer surface of the main body 131 by the fixing tape 141.

[0071] Figures 6 and 7 are plan views showing parts of a battery cell according to an exemplary embodiment of the present invention. Below, the battery cell shown in Figures 6 and 7 will be described, focusing on the differences from the battery cell 100 described with reference to Figures 1 to 4.

[0072] Referring to Figure 6, the profile of the second edge 1333 of the sealing joint 133 can include a curve at least partially. The width of the sealing joint 133 can increase as it moves away from the first point, while the sealing joint 133 has a minimum width W1 at a first point within its center 133c.

[0073] Referring to Figure 7, the width of the sealing joint 133 may be constant at its central point 133c. At the edges 133e of the sealing joint 133, the width of the sealing joint 133 can increase as it moves away from the central point 133c.

[0074] Figure 8 is a perspective view showing a battery assembly 10 according to an exemplary embodiment of the present invention.

[0075] Referring to Figure 8, the 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 (for example, the X direction), and cooling pads 200 may be placed between two adjacent battery cells 100.

[0076] The cooling pad 200 can be positioned between two battery cells 100 adjacent to each other in a first direction (e.g., the Y direction). The two battery cells 100 can be separated in the first direction (e.g., the Y direction) by the cooling pad 200. The cooling pad 200 can be attached to the sides of the main body 131 of the cover sheet 130 of the adjacent battery cell 100 and / or to the MTB housing 122.

[0077] The cooling pad 200 can be configured to cool adjacent battery cells 100. In some embodiments, the cooling pad 200 can be configured to cool adjacent battery cells 100 by absorbing heat from them. For example, the cooling pad 200 may include an endothermic material layer inside. For example, the endothermic material layer of the cooling pad 200 may include an absorbent material such as a super absorbent polymer (SAP). The cooling pad 200 can be placed between adjacent battery cells 100 in a first direction (e.g., the Y direction) and function as a thermal barrier to thermally separate the battery cells 100. Since the cooling pad 200 is placed between multiple battery cells 100, if any one of the multiple battery cells 100 ignites, the thermal transfer between the ignited battery cell 100 and the other battery cells 100 can be blocked or suppressed by the cooling pad 200.

[0078] Furthermore, the cooling pad 200 is configured to have a predetermined rigidity through its internal support structure and / or internal filler, thereby preventing or suppressing deformation of the battery cells 100 due to swelling. In addition, the cooling pad 200 can be configured to have a predetermined elasticity through its internal support structure and / or internal filler, and can be configured to elastically deform in a first direction (e.g., the Y direction), which is the arrangement direction of the battery cells 100. By elastically deforming in the first direction (e.g., the Y direction), the cooling pad 200 can function as a buffer pad against deformation of the battery cells 100 (e.g., deformation of the battery cells 100 due to swelling).

[0079] According to an exemplary embodiment of the present invention, cooling pads 200 that function as a thermal barrier and buffer are placed between adjacent battery cells 100, thereby preventing thermal transfer between the battery cells 100 and improving the structural safety of the battery cells 100. This improves the safety and reliability of the battery assembly 10 including the battery cells 100.

[0080] According to an exemplary embodiment, both sides of each individual battery cell 100 can be in contact with a cooling pad 200, and the bottom of each individual battery cell 100 can be in contact with an external heat sink. In this case, the hot gas or flame generated in each individual battery cell 100 can be released upward through the center 133c of the sealing joint 133, which has relatively low sealing strength. According to the present invention, the hot gas or flame generated inside the battery cell 100 is concentrated and released through the center 133c of the sealing joint 133 of the cover sheet 130, thereby preventing heat propagation between adjacent battery cells 100 and ultimately improving the safety of the battery assembly 10 including the battery cells 100.

[0081] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, there may be a variety of equivalents and modifications that can be substituted for them at the time of filing.

Claims

1. Electrode assembly and A cover sheet including a main body portion surrounding the electrode assembly and a sealing joint portion extending from the upper part of the main body portion and connected to the main body portion, A first multi-functional terminal block (first MTB) is located at one end of the electrode assembly and includes a first housing connected to the main body portion of the cover sheet, It is a battery cell, 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, so that the seal is first broken at the center of the sealing joint when the internal pressure of the battery cell rises. Battery cell.

2. The battery cell according to claim 1, further comprising a fixing tape for fixing the edge portion of the sealing joint to the main body portion.

3. The battery cell according to claim 1, further comprising an elastic band that tightly adheres the edge of the sealing joint and the main body of the cover sheet to the first housing.

4. The battery cell according to claim 1, wherein the main body portion of the cover sheet is attached to the first housing.

5. The battery cell according to claim 1, wherein the sealing joint is a joint formed by joining the first and second portions of the cover sheet together.

6. The sealing joint includes a first edge connected to the main body and a second edge opposite to the first edge. The profile of the second edge of the sealing joint includes a plurality of straight lines, The battery cell according to claim 1.

7. The sealing joint includes a first edge connected to the main body and a second edge opposite to the first edge. The profile of the second edge of the sealing joint includes a curve. The battery cell according to claim 1.

8. The battery cell according to claim 1, wherein, at the edge of the sealing joint, the width of the sealing joint decreases as it moves away from the end along the first direction of the sealing joint.

9. The battery cell according to claim 1, wherein the width of the sealing joint is uniform in the central part of the sealing joint.

10. The battery cell according to claim 1, wherein the first MTB is mounted in the first housing and further includes external terminals connected to the electrode leads of the electrode assembly.

11. The battery cell according to claim 1, wherein the first MTB further includes a venting disc mounted on the first housing, the venting disc being configured to burst and release gas when the internal pressure of the battery cell increases.

12. The first MTB further includes a check valve mounted in the first housing, The check valve is configured to open to release internal gas when the internal pressure of the battery cell is higher than a reference pressure, and to close again after the internal pressure has eased. The battery cell according to claim 1.

13. The battery cell according to claim 1, further comprising a second multi-functional terminal block (second MTB) spaced apart from the first MTB in a first direction with the electrode assembly in between, wherein the second MTB includes a second housing connected to the main body portion of the cover sheet.

14. Multiple battery cells, Includes a cooling pad positioned between the plurality of battery cells, A battery assembly, Each of the aforementioned plurality of battery cells is Electrode assembly and A cover sheet including a main body portion surrounding the electrode assembly and a sealing joint portion extending from the upper part of the main body portion and connected to the main body portion, The electrode assembly includes a multi-functional terminal block (MTB) which is located at one end of the electrode assembly and includes a housing connected to the main body portion of the cover sheet, 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, so that the seal is first broken at the center of the sealing joint when the internal pressure of the battery cell increases. Battery assembly.

15. The main body portion of the cover sheet includes an upper portion that covers the upper surface of the electrode assembly and a side portion that covers the side surface of the electrode assembly. The cooling pad contacts the side portion of the main body of the cover sheet, The sealing joint is connected to the upper part of the main body of the cover sheet. The battery assembly according to claim 14.

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