Secondary battery and secondary battery module comprising same

Abstract

Disclosed are a secondary battery and a secondary battery module including the same. The secondary battery includes: an electrode assembly including a first electrode, a second electrode, and a separator; a case configured to accommodate the electrode assembly, the case having an opening; a cap plate coupled to the one opening of the case, the cap plate including an injection port through which an electrolyte is injected into the case; and a gas discharge portion coupled to the injection port of the cover plate, the gas discharge portion configured to discharge gas generated inside the housing.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a secondary battery and a secondary battery module including the same. BACKGROUND

[0002] Unlike a primary battery designed not to be (re)charged, a secondary (or rechargeable) battery is a battery designed to be discharged and recharged. Low-capacity secondary batteries are used for portable small electronic devices such as smartphones, feature phones, notebook computers, digital cameras, and camcorders, and high-capacity secondary batteries are widely used as a power source to drive an electric motor in a hybrid vehicle and an electric vehicle and for storing electric power (e.g., home and / or utility-scale power storage). A secondary battery generally includes an electrode assembly including a positive electrode and a negative electrode, a case accommodating the electrode assembly, and an electrode terminal connected to the electrode assembly.

[0003] The above-described information disclosed in this BACKGROUND section is to enhance the understanding of the background of the disclosure, and as such, it can include information that does not constitute the related (prior) art. SUMMARY

[0004] Embodiments include a secondary battery including: an electrode assembly including a first electrode, a second electrode, and a separator; a case configured to accommodate the electrode assembly, the case having an opening; a cover coupled to the opening of the case, the cover including an injection port through which an electrolyte is injected into the case; and a gas discharge portion coupled to the injection port of the cover, the gas discharge portion configured to discharge a gas generated inside the case.

[0005] The gas discharge portion can include: a gas flow path tube coupled to the injection port, through which the gas flows; a pressure control member configured to move according to a pressure of the gas; and a housing accommodating the gas flow path tube.

[0006] The gas flow path tube can include: a flow path inlet through which the gas flows from inside the case into the gas flow path tube; a flow path outlet in contact with the injection port, through which the gas is discharged; and an anti-backflow film at the flow path inlet to prevent backflow of the electrolyte.

[0007] The gas flow path tube can be U-shaped.

[0008] The gas flow path tube can be M-shaped.

[0009] The pressure control member can seal the flow path outlet if the pressure of the gas is less than a critical pressure.

[0010] If the gas pressure is greater than or equal to the critical pressure, the pressure control component can move due to the gas pressure. The pressure control component is spaced apart from the flow path outlet, and the gas can be discharged to the injection port through the flow path outlet.

[0011] The pressure control component may include a metal ball within the injection port, which may have a diameter larger than the diameter of the flow path outlet.

[0012] The mass of the metal sphere can be determined based on the critical pressure.

[0013] The pressure control component may include: an elastic member located above the injection port, the elastic member being configured to contract or relax under the pressure of the gas; and a sealing member being configured to move according to the pressure of the gas and to seal the flow path outlet according to the elastic force of the elastic member.

[0014] The elastic modulus of an elastic component can be determined based on the critical pressure.

[0015] If the gas pressure is less than the critical pressure, the sealing member can seal the outlet of the flow path.

[0016] If the gas pressure is greater than or equal to the critical pressure, then: the sealing member can move according to the gas pressure to separate itself from the flow path outlet, thereby causing the elastic member to contract, and the gas can be discharged to the injection port through the flow path outlet.

[0017] The sealing component may include at least one of bolts and cork.

[0018] The gas flow path pipe may include at least one of ceramic, zirconium oxide, epoxy resin, polycarbonate, polysulfone, polyimide, polyoxymethylene and polytetrapropylene.

[0019] The embodiment includes a secondary battery module comprising: a plurality of secondary batteries; and a module frame configured to support the plurality of secondary batteries, wherein each of the plurality of secondary batteries includes: an electrode assembly including a first electrode, a second electrode, and a separator; a housing housing the electrode assembly having an opening; a cover plate connected to the opening of the housing, the cover plate including an injection port through which electrolyte is injected into the housing; and a gas venting section connected to the injection port of the cover plate, the gas venting section being configured to vent gas generated inside the housing.

[0020] The gas discharge unit may include: a gas flow path pipe connected to the injection port through which gas flows; a pressure control member configured to move according to the gas pressure; and a housing that houses the gas flow path pipe.

[0021] The gas flow path tube may include: a flow path inlet through which gas flows into the gas flow path tube; a flow path outlet in contact with the injection port through which gas is discharged; and an anti-backflow membrane at the flow path inlet to prevent electrolyte backflow.

[0022] The pressure control component may include: an elastic member having one end in contact with the module frame and another end above the injection port, the elastic member being configured to contract or relax according to the pressure of the gas; and a sealing member being configured to move according to the pressure of the gas, the sealing member sealing the flow path outlet according to the elastic force of the elastic member.

[0023] If the gas pressure is greater than or equal to the critical pressure, then: the sealing member can move according to the gas pressure to separate itself from the flow path outlet, thereby causing the elastic member to contract, and the gas is discharged to the injection port through the flow path outlet.

[0024] However, the technical problems to be solved by this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the following description of this disclosure other problems not mentioned herein, as well as aspects and features of this disclosure in solving these problems.

[0025] However, the aspects and features of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the detailed description below that other aspects and features not mentioned will be apparent. Attached Figure Description

[0026] The accompanying drawings illustrate embodiments of the present disclosure, and together with the detailed description thereof, further describe aspects and features of the present disclosure. Therefore, this disclosure should not be construed as limited to the drawings.

[0027] Features will become apparent to those skilled in the art from the detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0028] Figure 1 The illustration shows a perspective view of a secondary battery according to one or more embodiments of the present disclosure;

[0029] Figure 2 The figure shows a cross-sectional view of a secondary battery according to one or more embodiments of the present disclosure;

[0030] Figure 3A and Figure 3B The illustration shows an enlarged view of a gas emission section according to one or more embodiments of the present disclosure;

[0031] Figure 4 and Figure 5 The illustration shows an enlarged view of a gas emission section according to one or more other embodiments of the present disclosure;

[0032] Figure 6 The figure shows a perspective view of a secondary battery module according to one or more embodiments of the present disclosure;

[0033] Figure 7 The figure shows a cross-sectional view of a secondary battery module according to one or more embodiments of the present disclosure;

[0034] Figure 8A and Figure 8B The illustration shows an enlarged view of a gas emission section according to one or more embodiments of the present disclosure; and

[0035] Figure 9A and Figure 9B The illustration shows an enlarged view of a gas emission section according to one or more embodiments of the present disclosure. Detailed Implementation

[0036] Example implementations will now be described more fully below with reference to the accompanying drawings; however, example implementations may be implemented in different forms and should not be construed as limited to the one or more implementations set forth herein. Rather, these implementations are provided so that this disclosure will be thorough and complete and will fully convey exemplary implementations to those skilled in the art.

[0037] In the accompanying drawings, the dimensions of layers and regions may be exaggerated for clarity. It should also be understood that when a layer or element is referred to as "on" another layer or substrate, it may be directly on the other layer or substrate, or an intervening layer may be present. Furthermore, it should be understood that when a layer is referred to as "below" another layer, it may be directly below, and one or more intervening layers may be present. Additionally, it will be understood that when a layer is referred to as "between two layers," it may be the only layer between the two layers, or one or more intervening layers may be present. The same reference numerals refer to the same elements throughout.

[0038] In the following, embodiments of this disclosure will be described in detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as having a general or dictionary meaning, but should be interpreted in a meaning and concept consistent with the technical spirit of this disclosure, based on the principle that the inventor is capable of properly defining the concepts of the terms to best describe his / her embodiments as his / her own lexicographer.

[0039] The embodiments described in this specification and the constructions shown in the accompanying drawings are only some of the embodiments of this disclosure and do not represent all the technical spirit, aspects, and features of this disclosure. Accordingly, it should be understood that various equivalents and modifications are possible at the time of filing this application, which can replace or modify the embodiments described herein.

[0040] It will be understood that when an element or layer is referred to as being "on" another element or layer, "connected to," or "attached to" another element or layer, the element or layer may be directly on, connected to, or attached to the other element or layer, or one or more intermediary elements or layers may be present. When an element or layer is referred to as being "directly on" another element or layer, "directly connected to," or "directly attached to" another element or layer, no intermediary element or layer is present. For example, when a first element is described as being "attached" or "connected" to a second element, the first element may be directly attached to or connected to the second element, or the first element may be indirectly attached to or connected to the second element via one or more intermediary elements.

[0041] In the accompanying drawings, the dimensions of various elements, layers, etc., may be exaggerated for clarity of illustration. The same reference numerals denote the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the items listed. Furthermore, when describing embodiments of this disclosure, the use of "may" means "one or more embodiments of this disclosure." The expressions "at least one of" and "any one of" modify the entire list of elements without modifying individual elements in the list when placed after the list of elements. When phrases such as "at least one of A, B, and C," "at least one of A, B, or C," "at least one selected from the group of A, B, and C," or "at least one selected from A, B, and C" are used to specify a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, C, A and B, A and C, B and C, or A and B and C, A, B, and C. As used herein, the term "use" and its variations may be considered synonymous with the term "utilize" and its variations, respectively. As used herein, the terms “substantially,” “approximately,” and similar terms are used as approximate terms rather than terms of degree and are intended to describe the inherent biases of measurements or calculations that would be recognized by one of ordinary skill in the art.

[0042] It will be understood that although the terms "first," "second," "third," etc., can be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0043] In this document, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” are used to describe the relationship between one element or feature as shown in the figures and another (or several) other elements or features. It will be understood that, in addition to the orientation shown in the figures, spatial relative terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features will be oriented “above” or “directly above” other elements or features. Therefore, the term “below” can include both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptive terms used herein should be interpreted accordingly.

[0044] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “an” are intended to include the plural forms as well. It will be further understood that, when used in this specification, the term “comprising” designates the presence of stated features, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0045] Furthermore, any numerical range disclosed and / or enumerated herein is intended to include all subranges with the same numerical precision within the enumerated range. For example, the range “1.0 to 10.0” is intended to include, for example, 2.4 to 7.6, all subranges between the stated minimum value of 1.0 and the stated maximum value of 10.0 (inclusive), i.e., all subranges with a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0. Any maximum numerical limit described herein is intended to include all smaller numerical limits, and any minimum numerical limit described in this specification is intended to include all larger numerical limits. Therefore, the applicant reserves the right to amend this specification (including the claims) to explicitly detail any subranges included within the scope expressly described herein.

[0046] Referring to two compared elements, features, etc., as "identical" can mean that they are "substantially identical." Therefore, the phrase "substantially identical" can include cases with deviations considered low in the art (e.g., deviations below 5%). Additionally, when a parameter is stated to be consistent within a given region, this can mean that it is consistent in terms of average value.

[0047] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0048] Placing any element "above (or below)" or "above (below)" another element can mean that the arbitrary element can contact the upper (or lower) surface of the element, and that another element can also be located between the element and the arbitrary element disposed on (or below) the element.

[0049] Additionally, it will be understood that when a component is referred to as “connected,” “linked,” or “attached” to another component, these components can be directly “connected,” “linked,” or “attached” to each other, or another component can be “between” these components.

[0050] Throughout this specification, unless otherwise stated, when “A and / or B” is mentioned, it means A, B, or A and B. That is, “and / or” includes any or all combinations of the enumerated items. Unless otherwise stated, when “C to D” is mentioned, it means C and below D.

[0051] The terminology used herein is for the purpose of describing particular embodiments and is not intended to limit this disclosure.

[0052] During use, a large amount of gas may be generated inside the secondary battery due to various reasons such as chemical reactions occurring within it. In particular, gas generation within the secondary battery may increase when high-nickel anode materials are used in lithium-ion batteries with high capacity and high energy. Although degassing processes are included in the manufacturing process of the secondary battery to remove gases generated during manufacturing, they cannot remove the large amounts of gas generated during use. Consequently, expansion occurs when the internal pressure of the secondary battery increases due to the gases generated during its use. This expansion can lead to rupture of the secondary battery, thereby reducing its safety and lifespan. This disclosure presents a secondary battery 1 including a gas emission section 100 that mitigates this phenomenon.

[0053] Figure 1 The illustration shows a perspective view of a secondary battery 1 according to one or more embodiments of the present disclosure, and Figure 2 The figure shows a cross-sectional view of a secondary battery 1 according to one or more embodiments of the present disclosure.

[0054] See Figure 1 The secondary battery 1 may include: an electrode assembly; a housing 20 in which the electrode assembly is housed; a cover assembly 10 connected to an opening in the housing 20; a terminal 30; and an exhaust portion 40.

[0055] As an example, the secondary battery 1 according to one or more embodiments will be described as a lithium-ion secondary battery having a prismatic shape. However, this disclosure is applicable to various types of batteries, such as lithium polymer batteries, cylindrical batteries, etc.

[0056] The housing 20 forms the overall appearance of the secondary battery 1 and can be made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. The housing 20 provides space to house the electrode assembly and has an open side.

[0057] The housing 20 can accommodate the electrode assembly. See also Figure 2 The electrode assembly can be formed by alternately stacking a first electrode 300, a diaphragm 304, and a second electrode 302, which are formed into a plate shape or a thin film shape. Multiple first electrodes 300, second electrodes 302, and diaphragms 304 can be present. The electrode assembly can be stacked. As another example, the electrode assembly can be a Z-stacked electrode assembly, wherein the first electrode 300 and the second electrode 302 are inserted into opposite sides of a diaphragm folded into a Z-stack. The first electrode 300 of the electrode assembly can act as a positive electrode, and the second electrode 302 can act as a negative electrode. The reverse is also possible.

[0058] The first electrode 300 can be formed by applying a first electrode active material (such as a transition metal oxide) to a first electrode substrate formed of a metal foil (such as aluminum or an aluminum alloy), and may include a region of first electrode tab (or a first uncoated portion) where the first electrode active material is not applied. The first electrode tab can serve as a current flow path between the first electrode 300 and the first current collector plate.

[0059] The second electrode 302 can be formed by applying a second electrode active material (e.g., graphite or carbon) to a second electrode substrate formed of a metal foil (such as a metal foil such as copper, copper alloy, nickel, or nickel alloy), and may include a second electrode tab (or a second uncoated portion) in a region where no second electrode active material is applied. The second electrode tab can serve as a current flow path between the second electrode 302 and the second current collector.

[0060] The separator can prevent short circuits between the first electrode 300 and the second electrode 302 while allowing lithium ions to move. The separator can be made of, for example, a polyethylene membrane, a polypropylene membrane, a polyethylene-polypropylene membrane, or other materials, but is not limited thereto.

[0061] Multiple first electrode contacts and multiple second electrode contacts can be spaced apart from each other and can be positioned on the upper side of the electrode assembly. This is for ease of description based on the illustration, and the positions of the first and second electrode contacts can change when the electrode assembly is rotated left-right or up-down.

[0062] The cover assembly 10 can seal the opening of the housing 20. The cover assembly 10 may include a cover plate 11 (see...). Figure 2The housing includes terminals 30, an injection port 12, and an exhaust portion 40. A cover plate 11 can be attached to the housing 20 (e.g., to an opening in the housing 20). For example, the cover plate 11 can be welded to the housing 20. The cover plate 11 can seal the opening in the housing 20.

[0063] The cover plate 11 may include an injection port 12.

[0064] An injection port 12 may be formed on the cover plate 11. Electrolyte can be injected into the housing 20 through the injection port 12. After the electrolyte injection is completed, the injection port 12 can be sealed using a sealing member such as a plug.

[0065] Terminal 30 may be formed on cover plate 11. Terminal 30 may include a first terminal and a second terminal. The first terminal may be electrically connected to a first electrode 300. The second terminal may be electrically connected to a second electrode 302.

[0066] A venting portion 40 may be formed on the cover plate 11. The venting portion 40 can be formed by connecting a venting member to a vent hole formed on the cover plate 11. The venting portion 40 can prevent battery explosion or chain reactions caused by heat from other batteries disposed adjacent to the battery. For example, the venting portion 40 can be configured to open when the internal pressure of the battery exceeds a predetermined threshold pressure. This threshold pressure can be set differently depending on the battery's application, materials, and uses. As another example, the venting portion 40 can be configured to open when the internal temperature exceeds a predetermined threshold temperature.

[0067] The secondary battery 1 can be a lithium battery cell or a sodium battery cell, etc. However, the secondary battery 1 includes all batteries capable of repeatedly providing power through charging and discharging.

[0068] To facilitate based on Figure 1 The secondary battery shown in the figure is described in detail. The positions of the cover plate 11, injection port 12, terminal 30 and venting part 40 can vary depending on the type of secondary battery 1 when rotated left and right or up and down.

[0069] See Figure 2 The secondary battery 1 may include a cover assembly 10, a housing 20, terminals 30, an exhaust portion 40, an electrode assembly 50, a current collector 60, and a gas discharge portion 100.

[0070] The cover assembly 10 of the secondary battery 1 may include a cover plate 11 covering an opening in the housing 20. The housing 20 and the cover plate 11 may be made of a conductive material. Terminals 30 electrically connected to the positive or negative electrode may be mounted to protrude outwards through the cover plate 11. Terminals 30 protruding outside the cover plate 11 may be secured to the cover plate 11. For example, the terminals 30 may have a rivet structure to be riveted to the cover plate 11, or they may be welded to the cover plate 11. Each terminal 30 may be electrically connected to a current collector 60, including a positive electrode current collector or a negative electrode current collector. For example, the terminal 30 may be welded and connected to both the positive and negative electrode current collectors 60. However, the terminal 30 may be integrally formed with the positive or negative electrode current collector 60.

[0071] The cover 11 may include a venting portion 40 with a notch. The venting portion 40 may be configured to open when the internal pressure of the battery exceeds a predetermined threshold pressure.

[0072] The cover plate 11 may include an injection port 12 for injecting electrolyte. For example, the injection port 12 may be formed in the cover plate 11, and a pressure control member 110 may be connected to the injection port 12. The injection port 12 may be a through hole formed in the cover plate 11. The injection port 12 may be configured to inject electrolyte into the housing 20 after the cover plate 11 is connected to an opening in the housing 20 to seal the housing 20.

[0073] The cover assembly 10 may include a gas discharge section 100 for discharging gases generated inside the secondary battery 1. For example, the gas discharge section 100 may be connected to the injection port 12 of the cover plate 11, and the gas discharge section 100 may discharge gases generated inside the housing 20.

[0074] The gas discharge unit 100 may include a pressure control member 110, a gas flow path pipe 120, and a housing 130. The pressure control member 110 may be disposed inside the injection port 12 and may move depending on the gas pressure. For example, if the amount of gas generated inside the secondary battery 1 increases and the internal pressure of the secondary battery 1 increases, the pressure control member 110 may move upward in the Z-axis direction inside the injection port 12. The gas flow path pipe 120 may be connected to the injection port 12, and gas may flow through the gas flow path pipe 120. When the amount of gas increases, high-pressure gas may flow into the gas flow path pipe 120, and the gas may flow towards the injection port 12 by flowing through the gas flow path pipe 120. Accordingly, the pressure control member 110 disposed in the injection port 12 may rise according to the gas pressure.

[0075] The housing 130 can be positioned below the injection port 12 of the cover plate 11 and can accommodate the gas flow path pipe 120. The material of the housing 130 can be carbon black, but the material can be varied.

[0076] Because the secondary battery 1 includes a gas discharge section 100, the gas generated inside the secondary battery 1 can be easily discharged. By discharging the gas, the expansion of the secondary battery 1 can be reduced, which can improve the stability and lifespan of the secondary battery 1. By using the injection port 12 as part of the gas discharge flow path, the gas discharge structure can be implemented more simply.

[0077] See Figure 3A and Figure 3B The components and operation of the gas emission unit 100 are described in detail.

[0078] Figure 3A and Figure 3B The illustration shows an enlarged view of a gas emission unit 100 according to one or more embodiments of the present disclosure.

[0079] See Figure 3A and Figure 3B The gas flow path pipe 120 may include a flow path inlet 121, a flow path outlet 122, and an anti-backflow membrane 123. As shown, the gas flow path pipe 120 may be formed in a U-shape. For example, because the electrolyte inside the secondary battery has a higher density than gas, most of the electrolyte may be located in the lower part of the secondary battery. However, depending on the location of the secondary battery 1, some of the electrolyte may flow back through the gas flow path pipe 120. To prevent this problem, the gas flow path pipe 120 may be formed in a U-shape. Even when the secondary battery 1 is placed in opposite directions, the U-shaped gas flow path pipe 120 can minimize electrolyte backflow. As described above, while preventing electrolyte leakage from the secondary battery 1 through the U-shaped gas flow path pipe 120, only the gas inside the secondary battery 1 can be discharged. However, the form of the gas flow path pipe 120 may include all flow paths through which gas can pass through the housing 130 and be discharged to the injection port 12.

[0080] The gas flow path conduit 120 may be made of an insulating material. For example, the gas flow path conduit 120 may include at least one of ceramics (e.g., Al2O3), zirconium oxide, epoxy resin, polycarbonate (PC), polysulfone (PSU), polyimide (PI), polyoxymethylene (POM), and polytetrafluoroethylene (PTFE), or may be made of a composition or compound comprising at least one of ceramics (e.g., Al2O3), zirconium oxide, epoxy resin, polycarbonate (PC), polysulfone (PSU), polyimide (PI), polyoxymethylene (POM), and polytetrafluoroethylene (PTFE), but this disclosure is not limited thereto.

[0081] The flow path inlet 121 can be one surface (e.g., one end) of the gas flow path pipe 120 leading into the interior of the housing 20. That is, the flow path inlet 121 is the inlet region of the gas flow path pipe 120 into which gas can flow. The flow path outlet 122 can be another open surface (e.g., the other end) of the gas flow path pipe 120 that is in contact (e.g., fluid communication) with the injection port 12. That is, the flow path outlet 122 is the outlet region of the gas flow path pipe 120 through which gas can be discharged. Here, the discharged gas can be discharged to the outside of the secondary battery 1 through the injection port 12.

[0082] A backflow prevention membrane 123 may be disposed at the flow path inlet 121 to prevent electrolyte backflow. The backflow prevention membrane 123 may comprise a porous membrane. Here, the porous membrane may be made of a composition or compound comprising at least one of polycarbonate (PC), polysulfone (PSU), polyimide (PI), polyoxymethylene (POM), and polytetrafluoroethylene (PTFE), but other materials are possible.

[0083] A pressure control component 110 may be disposed in the injection port 12. For example, the pressure control component 110 may include a metal ball having a diameter larger than the diameter of the flow path outlet 122. Accordingly, if no gas is generated in the secondary battery 1, the metal ball serving as the pressure control component 110 may seal the flow path outlet 122.

[0084] Furthermore, the mass of the metal ball, which serves as the pressure control component 110, can be determined based on the critical pressure. The critical pressure is a pressure level set during the manufacturing and / or testing of the secondary battery 1, and can be a predetermined pressure level that reduces the stability and lifespan of the secondary battery 1. For example, the mass of the metal ball is determined based on a predetermined critical pressure, and the mass of the metal ball can increase as the critical pressure increases. If the gas generated inside the secondary battery 1 increases, the overall pressure inside the secondary battery 1 will increase due to the gas pressure. For example, the pressure inside the manufactured secondary battery 1 can typically be between 0.01 and 0.07 MPa. In this case, atmospheric pressure is approximately 0.1 MPa greater than the internal pressure of the secondary battery 1. Subsequently, as the secondary battery 1 is used, the pressure of the gas generated inside the secondary battery 1 may exceed atmospheric pressure. In this case, the pressure of the gas generated inside the secondary battery 1 may reach the critical pressure. At this point, as the metal ball moves to a position spaced apart from the flow path outlet 122, the gas can be discharged to the outside of the secondary battery 1 through the injection port 12.

[0085] As an example, such as Figure 3AAs shown, when the pressure of the gas generated inside the secondary battery 1 is less than the critical pressure, the metal ball, which is the pressure control member 110, can seal the flow path outlet 122.

[0086] As an example, such as Figure 3B As shown, when the pressure of the gas generated inside the secondary battery 1 is greater than or equal to the critical pressure, the metal ball serving as the pressure control member 110 can move according to the gas pressure. That is, the pressure control member 110 can be spaced apart from the flow path outlet 122. Accordingly, the gas can be discharged to the injection port 12 through the flow path outlet 122. The gas generated inside the secondary battery 1 can be discharged to the outside of the secondary battery 1 through the injection port 12. For example, when the gas pressure is higher than or equal to the critical pressure, the metal ball serving as the pressure control member 110 can separate from the flow path outlet 122 by rising in the Z-axis direction within the injection port 12. Accordingly, the gas can be discharged to the outside of the secondary battery 1 through the injection port 12.

[0087] Subsequently, as the gas generated inside the secondary battery 1 is discharged to the outside, the gas pressure can again fall below the critical pressure. In this case, the metal ball, which serves as the pressure control member 110, can descend in the Z-axis direction and reseal the flow path outlet 122.

[0088] As described above, the critical pressure can be preset by the pressure control component 110, and when the critical pressure is reached, the gas inside the secondary battery 1 can be easily discharged.

[0089] Figure 4 and Figure 5 The illustration shows an enlarged view of a gas emission section 100 according to one or more other embodiments of the present disclosure. For ease of description, the focus will be on... Figure 3A and Figure 3B To describe the differences in the gas emission section described in the text Figure 4 and Figure 5 The gas emission section 100.

[0090] See Figure 4 and Figure 5The gas flow path pipe 120 can be formed in an M-shape (or W-shape) (e.g., zigzag). Even when the secondary battery 1 is placed in opposite directions, the M-shaped gas flow path pipe 120 can minimize electrolyte backflow. The M-shaped gas flow path pipe 120 can reduce the gas flow velocity. Furthermore, since the pressure change of the gas flowing through the injection port 12 is reduced, the stability of the gas discharge section 100 can be improved. On the other hand, compared with a straight or U-shaped gas flow path pipe 120, the M-shaped gas flow path pipe 120 has a complex flow path. Accordingly, the M-shaped gas flow path pipe 120 can prevent substances other than gas from flowing in and precipitating into the flow path. With the electrolyte leakage of the secondary battery 1 prevented by the M-shaped gas flow path pipe 120, only the gas inside the secondary battery 1 can be discharged.

[0091] In one or more embodiments, such as Figure 4 As shown, the flow path inlet 121 can be located on the lower side of the housing 130. The gas flow path pipe 120 can be formed in a zigzag shape, extending in the X-axis direction and rising in the Z-axis direction. Accordingly, the flow path outlet 122 of the gas flow path pipe 120 can contact the injection port 12.

[0092] In one or more embodiments, such as Figure 5 As shown, the flow path inlet 121 may be located on the lower side of the housing 130. The gas flow path pipe 120 may have a zigzag shape, with the flow path extending in the Z-axis direction and the flow path outlet 122 contacting the injection port 12. However, this disclosure is merely an example, and the gas discharge section 100 may include various types of gas flow path pipes 120.

[0093] Figure 6 The illustration shows a perspective view of a secondary battery module 1000 according to one or more embodiments of the present disclosure, and Figure 7 The figure shows a cross-sectional view of a secondary battery module 1000 according to one or more embodiments of the present disclosure. Figure 6 The secondary battery 1 can be with Figure 1 to Figure 5 The secondary battery 1 is the same as or similar to it. Therefore, for better understanding and ease of description, the main description will be related to... Figure 1 to Figure 5 The differences described in the text.

[0094] See Figure 6 and Figure 7 The secondary battery module 1000 may include a plurality of secondary batteries 1 and a module frame 200 supporting the secondary batteries 1. For example, the secondary batteries 1 may be accommodated in the module frame 200 in a stacked manner (e.g., along the Y-axis direction).

[0095] In one or more embodiments, each of the plurality of secondary batteries 1 may include an electrode assembly; a housing 20 in which the electrode assembly is housed; a cover 11 connected to an opening in the housing 20; and a gas vent 100. The secondary battery 1 may further include a terminal 30 and an exhaust portion 40. In one or more embodiments, each of the plurality of secondary batteries 1 may include a cover assembly, and the cover assembly 10 may include a cover 11 and a gas vent 100. An injection port 12 may be formed on the cover 11.

[0096] In one or more embodiments, the gas discharge section 100 may include a pressure control member 110, a gas flow path pipe 120, and a housing 130. The pressure control member 110 may include an elastic member 111 and a sealing member 112. The elastic member 111 (e.g., one end of the elastic member 111) may be disposed above the injection port 12, and the elastic member 111 may contract or relax according to the gas pressure. Here, the elastic member 111 may include a spring, but any elastic material may be used. For example, one surface of the elastic member 111 (e.g., the other end) may contact the module frame 200. Meanwhile, the other surface of the elastic member 111 may contact the sealing member 112.

[0097] A sealing member 112 may be disposed in the injection port 12 and may move according to the gas pressure. The sealing member 112 may be spaced apart from the flow path outlet 122 to allow the elastic member 111 to contract. For example, one surface of the sealing member 112 may contact the elastic member 111. Simultaneously, another surface of the sealing member 112 may seal the flow path outlet 122. The sealing member 112 may seal the flow path outlet 122 based on the elasticity of the elastic member 111. In some embodiments, the sealing member 112 may indirectly seal the flow path outlet 122 by sealing the injection port 12. The sealing member 112 may include a bolt and / or a cork.

[0098] See Figure 8A and Figure 8B The components and operation of the pressure control element 110 are described in detail.

[0099] Figure 8A and Figure 8B The illustration shows an enlarged view of a gas emission unit 100 according to one or more embodiments of the present disclosure.

[0100] See Figure 8A and Figure 8B The gas flow path pipe 120 can be formed into a U-shape, but as... Figure 4 and Figure 5As shown, it can be formed in an M-shape (or W-shape or zigzag shape). However, this disclosure is only an example, and the gas flow path pipe 120 can take other forms.

[0101] In one or more embodiments, the pressure control member 110 may include an elastic member 111 and a sealing member 112 including bolts. The elastic modulus of the elastic member 111 may be determined based on a critical pressure. For example, the elastic modulus of the elastic member 111 may be determined according to a preset critical pressure, and the elastic modulus may increase as the critical pressure increases. Furthermore, the mass of the sealing member 112 may also be determined based on the critical pressure. The mass of the bolt serving as the sealing member 112 may be determined taking into account the elastic modulus.

[0102] The diameter of the sealing member 112 can be larger than the diameter of the flow path outlet 122. Accordingly, in the absence of gas generation in the secondary battery 1, the sealing member 112 can seal the flow path outlet 122.

[0103] In one or more embodiments, when the pressure of the gas generated inside the secondary battery 1 is less than the critical pressure, such as Figure 8A As shown, the bolt, which serves as a sealing member 112, can seal the flow path outlet 122.

[0104] As an example, such as Figure 8B As shown, when the pressure of the gas generated inside the secondary battery 1 is greater than or equal to the critical pressure, the bolt serving as the sealing member 112 can be moved by the gas pressure. As the bolt serving as the sealing member 112 rises in the Z-axis direction, the bolt can be spaced apart from the flow path outlet 122. Simultaneously, the elastic member 111 fixed to a surface of the module frame 200 can contract due to elastic force. Accordingly, the gas can be discharged to the injection port 12 through the flow path outlet 122. The gas generated inside the secondary battery 1 can be discharged to the outside of the secondary battery 1 through the injection port 12.

[0105] As the gas generated inside the secondary battery 1 is discharged to the outside, the pressure inside the secondary battery 1 can again fall below the critical pressure. In this case, the bolt, which serves as the sealing member 112, can be lowered in the Z-axis direction when the elastic member 111 relaxes. For example, the bolt, which serves as the sealing member 112, can reseal the flow path outlet 122.

[0106] Figure 9A and Figure 9B The illustration shows an enlarged view of a gas emission unit 100 according to one or more embodiments of the present disclosure.

[0107] See Figure 9AThe pressure control member 110 may include an elastic element 111 and a sealing member 112 including a cork. Here, the elastic modulus of the elastic element 111 may be determined based on a critical pressure. For example, the elastic modulus of the elastic element 111 may be determined according to a preset critical pressure, and the elastic modulus may increase as the critical pressure increases. Furthermore, the mass of the sealing member 112 may also be determined based on the critical pressure. The mass of the cork serving as the sealing member 112 may be determined considering the determined elastic modulus.

[0108] In one or more embodiments, such as Figure 9A As shown, when the pressure of the gas generated inside the secondary battery 1 is less than the critical pressure, the cork, which serves as the sealing member 112, can seal the flow path outlet 122.

[0109] At the same time, such as Figure 8B As shown, when the pressure of the gas generated inside the secondary battery 1 is greater than or equal to the critical pressure, the cork, which serves as the sealing member 112, can be moved by the gas pressure. As the cork, which serves as the sealing member 112, rises in the Z-axis direction, the cork can be spaced apart from the flow path outlet 122. The elastic member 111, fixed to a surface of the module frame 200, can contract due to elasticity. Accordingly, the gas can be discharged to the injection port 12 through the flow path outlet 122. The gas generated inside the secondary battery 1 can be discharged to the outside of the secondary battery 1 through the injection port 12.

[0110] As the gas generated inside the secondary battery 1 is discharged to the outside, the gas pressure can again fall below the critical pressure. The cork, which serves as the sealing member 112, can be lowered in the Z-axis direction when the elastic member 111 relaxes. The cork, which serves as the sealing member 112, can then reseal the flow path outlet 122.

[0111] During use, due to various reasons such as chemical reactions occurring within the secondary battery, a large amount of gas may be generated inside. The internal pressure of the secondary battery increases due to the generated gas, leading to expansion. This expansion may cause the secondary battery to rupture and reduce its stability and lifespan.

[0112] As described above, in this disclosure, because the secondary battery 1 includes a gas discharge section 100, the gas generated inside the secondary battery can be easily discharged. By discharging the gas, the expansion phenomenon of the secondary battery can be reduced, which can improve the stability and lifespan of the secondary battery.

[0113] Furthermore, the critical pressure can be set by the pressure control member 110, and when the critical pressure is reached, the gas inside the secondary battery 1 can be easily discharged.

[0114] Although this disclosure has been described above with respect to its embodiments, it is not limited thereto. Those skilled in the art will be able to make various modifications and variations thereto within the spirit of this disclosure and within the equivalents of the appended claims.

[0115] Thus far, exemplary embodiments have been disclosed. Although specific terminology has been used, it is used in a general and descriptive sense only, and is not intended to be limiting. In some cases, as would be apparent to those skilled in the art at the time of filing this application, unless specifically stated otherwise, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments. Accordingly, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A secondary battery comprising: an electrode assembly including a first electrode, a second electrode, and a separator; a case configured to accommodate the electrode assembly and having an opening; a cover coupled to the opening of the case, the cover including an injection port through which an electrolyte is injected into the case; and a gas discharge portion coupled to the injection port of the cover, the gas discharge portion being configured to discharge a gas generated inside the case. The gas discharge portion includes:

2. The secondary battery according to claim 1, wherein a gas flow path tube coupled to the injection port through which the gas flows; a pressure control member configured to move according to a pressure of the gas; and a housing accommodating the gas flow path tube. The gas flow path tube includes:

3. The secondary battery according to claim 2, wherein a flow path inlet through which the gas flows from inside the case into the gas flow path tube; a flow path outlet in contact with the injection port through which the gas is discharged; and an anti-backflow film at the flow path inlet to prevent backflow of the electrolyte. The gas flow path tube is U-shaped.

4. The secondary battery according to claim 3, wherein The gas flow path tube is M-shaped.

5. The secondary battery according to claim 3, wherein If the pressure of the gas is less than a critical pressure, the pressure control member seals the flow path outlet.

6. The secondary battery according to any one of claims 3 to 5, wherein If the pressure of the gas is greater than or equal to the critical pressure:

7. The secondary battery according to claim 6, wherein the pressure control member moves according to the pressure of the gas, the pressure control member is spaced apart from the flow path outlet, and the gas is discharged through the flow path outlet to the injection port. The pressure control member includes a metal ball having a diameter greater than a diameter of the flow path outlet within the injection port.

8. The secondary battery according to claim 7, wherein A mass of the metal ball is determined based on the critical pressure.

9. The secondary battery according to claim 8, wherein The pressure control member includes:

10. The secondary battery according to claim 7, wherein an elastic member on an upper side of the injection port, the elastic member being configured to contract or relax according to the pressure of the gas; and a sealing member configured to move according to the pressure of the gas and to seal the flow path outlet according to an elastic force of the elastic member. An elastic modulus of the elastic member is determined based on the critical pressure.

11. The secondary battery according to claim 10, wherein If the pressure of the gas is less than the critical pressure, the sealing member seals the flow path outlet.

12. The secondary battery according to claim 11, wherein If the pressure of the gas is greater than or equal to the critical pressure:

13. The secondary battery according to claim 12, wherein the sealing member moves according to the pressure of the gas to be spaced apart from the flow path outlet, thereby causing the elastic member to contract, and the gas is discharged through the flow path outlet to the injection port. The sealing member includes at least one of a bolt and a cork.

14. The secondary battery according to claim 13, wherein The gas flow path tube includes at least one of ceramic, zirconia, epoxy, polycarbonate, polysulfone, polyimide, polyoxymethylene, and polytetrafluoroethylene.

15. The secondary battery according to claim 3, wherein 16.A secondary battery module comprising: a plurality of secondary batteries; and a module frame configured to support the plurality of secondary batteries, wherein each of the plurality of secondary batteries includes: ​ ​ An electrode assembly including a first electrode, a second electrode, and a separator; A case accommodating the electrode assembly, the case having an opening; A cover coupled to the opening of the case, the cover including an injection port through which an electrolyte is injected into the case; and A gas discharge portion coupled to the injection port of the cover, the gas discharge portion being configured to discharge a gas generated inside the case.

17. The secondary battery module according to claim 16, wherein The gas discharge portion includes: A gas flow path tube coupled to the injection port through which the gas flows; A pressure control member configured to move according to a pressure of the gas; and An outer case accommodating the gas flow path tube.

18. The secondary battery module according to claim 17, wherein The gas flow path tube includes: A flow path inlet through which the gas flows from inside the case into the gas flow path tube; A flow path outlet in contact with the injection port through which the gas is discharged; and An anti-backflow film at the flow path inlet to prevent backflow of the electrolyte.

19. The secondary battery module according to claim 18, wherein The pressure control member includes: An elastic member having one end in contact with the module frame and the other end on an upper side of the injection port, the elastic member being configured to contract or relax by the pressure of the gas; and A sealing member configured to move according to the pressure of the gas, the sealing member sealing the flow path outlet by an elastic force of the elastic member. 20.The secondary battery module of claim 19, wherein: if the pressure of the gas is greater than or equal to a critical pressure, the sealing member moves according to the pressure of the gas to be spaced apart from the flow path outlet, thereby causing the elastic member to contract, and the gas is discharged through the flow path outlet to the injection port.

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