Secondary battery
Patent Information
- Application Number
- DE202024107115
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Priority Date
- 2024-01-15
- Filing Date
- 2024-12-09
- Publication Date
- 2025-03-27
- Estimated Expiration
- 2034-12-31
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The technology and implementations disclosed in this patent document generally relate to a secondary battery. BACKGROUND
[0002] A secondary battery is a type of energy storage device that can be repeatedly charged and discharged. Secondary batteries are widely used across various applications that rely on electricity as a power source. For example, secondary batteries serve as energy storage devices in devices ranging from small electronic devices, such as mobile phones, laptops, and tablets, to large devices, such as vehicles and aircraft. Recently, secondary batteries have been actively researched as power sources for vehicles. SUMMARY
[0003] The disclosed technology may be implemented in some embodiments to provide a secondary battery designed to improve its stability.
[0004] A secondary battery implemented based on some embodiments of the disclosed technology can be widely applied in the field of green technology, such as electric vehicles, battery charging stations and other battery-based solar power generation systems, wind power generation systems, and others. Additionally, the secondary battery of the disclosed technology can be used in environmentally friendly electric vehicles, hybrid vehicles, and others to prevent climate change by reducing air pollution and greenhouse gas emissions.
[0005] In one aspect of the disclosed technology, a secondary battery may include: a casing structured to receive an electrode assembly therein; a cover plate configured to seal an opening of the casing and including a first vent hole, the cover plate having a first polarity; an insulating member disposed at a lower portion of the cover plate and including a second vent hole positioned to coincide with a position of the first vent hole, the second vent hole having a larger diameter than the first vent hole; a current collector member disposed at a lower portion of the insulating member and electrically connected to the electrode assembly, the current collector member having a second polarity different from the first polarity;a guide member disposed in a lower portion of the second drain hole and electrically connected to the current collector member; and a short-circuit member containing a conductive material and disposed in the guide member, the short-circuit member configured to move upward to contact the cover plate in response to pressure generated within the housing.
[0006] The secondary battery may further include an elastic member disposed in the guide member and configured to apply pressure from above to the short-circuit member.
[0007] The guide element may include a first body having an open upper and lower portion, and a first lower portion shaped to extend from a lower end of the first body in both an inward and outward direction. The first lower portion may be electrically connected to the current collector element.
[0008] The short-circuit element may include a second body having an open upper portion, a second lower portion shaped to extend from a lower end of the second body in an outward direction, and a frangible portion formed in the second body and including a notch.
[0009] The short-circuiting element may further include a protrusion portion coupled to an outer periphery of the second body. The insulating element may include a receiving recess that receives the protrusion portion when the short-circuiting element moves upward.
[0010] At least one of the second body or the protrusion portion of the short-circuit member may have at least one cutout portion.
[0011] An inclined surface may be formed at an upper end of the protruding portion.
[0012] The protrusion portion may include a body portion coupled to an outer periphery of the second body, and an elastic protrusion portion extending from an upper end of the body portion in a downward direction to be inclined.
[0013] In another aspect of the disclosed technology, a secondary battery includes: a casing structured to receive an electrode assembly therein; a cover plate configured to seal an opening of the casing and include a first vent hole, the cover plate having a first polarity; an insulating member disposed at a lower portion of the cover plate and including a second vent hole positioned to coincide with a position of the first vent hole, the second vent hole having a larger diameter than the first vent hole; a current collector member disposed at a lower portion of the insulating member and electrically connected to the electrode assembly, the current collector member having a second polarity different from the first polarity; a guide member disposed in a lower portion of the second vent hole;a shorting element containing a conductive material and disposed within the guide element, the shorting element configured to move upward to contact the cover plate in response to pressure generated within the housing; and a shorting tab containing a conductive material and coupled to a lower portion of the shorting element, the shorting tab configured to contact the current collector element when the shorting element contacts the cover plate.
[0014] A secondary battery based on some embodiments of the disclosed technology may include a short-circuit element that performs a short-circuit function when an abnormality occurs, and a frangible portion formed in the short-circuit element to release internal gas. This allows components to perform their functions without the need for additional components, thereby simplifying the configuration.
[0015] However, technical effects achieved by embodiments of the disclosed technology are not necessarily limited to those described in this patent document. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Certain aspects, features and advantages of the disclosed technology are illustrated by the following detailed description with reference to the accompanying drawings. Fig. 1 is a schematic perspective external view of a secondary battery based on an embodiment. Fig. 2 is a cross-sectional view along the line I - I' of Fig. 1. Fig. 3 is a schematic exploded perspective view of elements in the Fig. 2 illustrated section “II”. Fig. 4 is a cross-sectional view of a guide member, a short-circuit member, and an elastic member coupled together in a secondary battery based on an embodiment. Fig. 5 to Fig. 7 are cross-sectional views of sequential operations of a short-circuit element in a secondary battery based on an embodiment. Fig. 8 is a diagram illustrating another embodiment of a short-circuit element in a secondary battery based on an embodiment. Fig. 9 is a diagram illustrating another embodiment of a short-circuit element in a secondary battery based on an embodiment. Fig. 10A and Fig. 10B are cross-sectional views of an operation of the short-circuit element of Fig. 9. Fig. 11 is a diagram illustrating another embodiment of a short-circuit element in a secondary battery based on an embodiment. Fig. 12A, Fig. 12B and Fig. 12C are cross-sectional views of an operation of the short-circuit element of Fig. 11. Fig. 13 to Fig. 15 are cross-sectional views of sequential operations of a short-circuit element in a secondary battery based on another embodiment. DETAILED DESCRIPTION
[0017] Various embodiments disclosed in this patent document will be described with reference to the accompanying drawings.
[0018] Secondary batteries can be classified into types, such as lead-acid batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and lithium-ion batteries, depending on the electrode material used. The secondary battery type is typically selected depending on factors such as rated capacity and usage environment. Compared to other types of secondary batteries, lithium-ion batteries offer relatively high voltages and capacities. For these reasons, lithium-ion batteries are widely used in applications requiring high-density energy storage, such as vehicle battery packs.
[0019] Secondary batteries, such as lithium-ion batteries, may contain a positive electrode, a negative electrode, a separator, and an electrolyte. The positive and negative electrodes are separated by a separator made of an insulating material. Secondary batteries can be charged or discharged by ions moving between the electrodes through the electrolyte.
[0020] If excessive heat is generated or the electrolyte decomposes due to overcharging, foreign matter intrusion, or damage to the insulating structure caused by external influences, the internal pressure of the secondary batteries may increase, potentially leading to ignition or explosion. To improve safety, various technical measures have been applied to the cover plate that seals the battery case.
[0021] In some embodiments, the term "secondary battery" may be used to indicate rechargeable batteries, such as lead-acid batteries, nickel-cadmium batteries, nickel-hydride batteries, and lithium-ion batteries. In some embodiments discussed in this patent document, the term "secondary battery" is used to indicate a lithium-ion battery. In general, lithium-ion batteries offer advantages such as being lightweight, having a high energy density, and having a low self-discharge rate. However, it should be noted that the features discussed in this patent document with respect to lithium-ion batteries are also applicable to other types of batteries.
[0022] In some embodiments, a secondary battery may include a single physical unit or a cluster unit that includes multiple physical units combined together. For example, depending on the classification criteria commonly used in the current automotive industry, a secondary battery may include a battery cell, a battery module, a battery pack, or others. In some embodiments, the secondary battery is a battery cell, a single unit. In some embodiments, a battery cell may be a basic component unit of a battery pack, including a positive electrode, a negative electrode, a separator, an electrolyte, and others. However, some embodiments disclosed in this patent document are also applicable to other types of cluster units, such as a battery module, a battery pack, and others.
[0023] In some embodiments, the secondary battery may include various types of packaged secondary batteries. For example, the secondary battery may be packaged in a cylindrical shape, a prismatic shape, a pouch shape, or others, depending on the classification criteria commonly used in the field. In some embodiments, the secondary battery may be packaged in a prismatic shape. A prismatic-shaped package, referred to as a prismatic-shaped battery, may generally have advantages in terms of durability, safety, and convenience of assembly. However, some embodiments disclosed in this patent document are also applicable to other types of packages, such as a cylindrical-shaped package or a pouch-shaped package.
[0024] In some embodiments, the secondary battery can be used in various applications that require electrical power. For example, the secondary battery can be used in vehicles that use electrical power as a primary power source or an auxiliary power source. In some embodiments, the secondary battery can be used in fields such as aviation, e.g., passenger aircraft, unmanned aerial vehicles, drones, as well as in electronic devices such as mobile phones, laptops, tablets, and power tools such as electric drills, electric grinders, and electric hammers. However, it should be understood that some embodiments discussed in this patent document are also applicable to a wide range of devices powered by electrical power beyond those mentioned above.
[0025] Fig. 1 is a schematic perspective external view of a secondary battery 100 based on an embodiment of the disclosed technology, and FIG. is a cross-sectional view taken along line I - I' in Fig. 1.
[0026] For simplicity, in some embodiments, a single battery cell having a prismatic shape is used as an example.
[0027] With reference to Fig. 1 and Fig. 2, the secondary battery 100 based on some embodiments may include a housing 110.
[0028] Housing 110 may provide an interior space in which an electrode assembly 120 or the like may be received. In one example, housing 110 has an approximately rectangular parallelepiped shape.
[0029] The housing 110 may include an opening 111 connected to the interior space. In one example, the opening 111 is located at an upper end of the housing 110. However, a position of the opening 111 may vary and is not necessarily limited to this example. The opening 111 may serve as a path for inserting the electrode assembly 120. Additionally, the opening 111 may serve as a connection space for an electrical connection between the electrode assembly 120 and an electrode terminal. The opening 111 may be closed or sealed by a cover plate 130.
[0030] The material of the housing 110 can be appropriately selected taking into account thermal and electrical conductivity, rigidity in accordance with the swelling of the electrode assembly 120, processability, and manufacturing costs. For example, the housing 110 can be formed from a metal material including aluminum, an aluminum alloy, or others.
[0031] The secondary battery 100 based on an embodiment may include the electrode assembly 120.
[0032] The electrode assembly 120 may be arranged in the interior of the housing 110. The electrode assembly 120 may include a first electrode body 121, a separator 122, and a second electrode body 123. In this case, the first electrode body 121 may function as a positive electrode, and the second electrode body 123 may function as a negative electrode. The reverse case may be possible. For simplicity, the following mainly describes a case in which the first electrode body 121 functions as a positive electrode.
[0033] The first electrode body 121 may include a positive electrode current collector and a positive electrode active material. In some embodiments, the positive electrode current collector may include aluminum, an aluminum alloy, or the like, and the positive electrode active material may include lithium cobalt oxide, lithium manganate, lithium nickel oxide, lithium iron phosphate, or the like. The positive electrode active material may be coated on a surface of the positive electrode current collector. A portion of the positive electrode current collector not coated with the positive electrode active material may function as a first tab 121a. In some embodiments, the first tab 121a may be provided as a plurality of first tabs 121a, and some or all of the plurality of first tabs 121a may be connected to a first current collector element 124.
[0034] The second electrode body 123 may include a negative electrode current collector and a negative electrode active material. In some embodiments, the negative electrode current collector may include copper, a copper alloy, nickel, a nickel alloy, or the like, and the negative electrode active material may include carbon, silicon, or the like. The negative electrode active material may be coated on a surface of the negative electrode current collector. A portion of the negative electrode current collector not coated with the negative electrode active material may function as a second tab 123a. In some embodiments, a plurality of second tabs 123a may be provided, and some or all of the plurality of second tabs 123a may be connected to a second current collector element 125.
[0035] The separator 122 may be disposed between the first electrode body 121 and the second electrode body 123. The separator 122 may limit physical contact between the first electrode body 121 and the second electrode body 123 and may serve to provide a path for ion movement. In some embodiments, the separator 122 may be formed from a polymer material including polyethylene, polypropylene, or the like. The separator 122 may include a dry separator and a wet separator. In some embodiments, the separator 122 may include a coating layer including a ceramic coating layer or the like.
[0036] The electrode assembly 120 may be formed by arranging the components in a wound or stacked manner. For example, the electrode assembly 120 may be formed to have a structure in which the first electrode body 121, the second electrode body 123, and the separator 122 are wound around an axis in a longitudinal direction or a transverse direction. Alternatively, the electrode assembly 120 may be formed to have a structure in which the wound structure is pressed in a direction approximately perpendicular to a winding axis. The wound structure may be referred to in the art as a "jelly roll" or the like.
[0037] For another example, the electrode assembly 120 may be formed to have a structure in which the first electrode body 121, the second electrode body 123, and the separator 122 are stacked. In some cases, the separator 122 in the stacked structure may be formed to have a structure in which a plurality of unit separators 122 are continuously folded and stacked sequentially based on the stacking of the first electrode body 121 and the second electrode body 123 in a longitudinal direction. The stacked structure may be referred to in the art as "stacking and folding" or "z-folding." The electrode assembly 120 may have various arrangements other than those mentioned above.
[0038] In some embodiments, the electrode assembly 120 may be formed by combining a plurality of units together. For example, the electrode assembly 120 may include one unit wound in a jelly roll fashion, and two or more units may be combined together to form the electrode assembly 120. In some embodiments, the electrode assembly 120 may include two jelly roll units combined together. In another example, the electrode assembly 120 may include one unit wound in a "stack and fold" fashion, and two or more units may be combined together to form the electrode assembly 120.
[0039] The electrode assembly 120 may be housed in the interior of the housing 110 along with an electrolyte. In some embodiments, the electrolyte may be formed from an organic solvent containing a lithium salt. For example, the lithium salt may include liquid or gel-like lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), or the like, and the organic solvent may include a cyclic carbonate such as ethylene carbonate (EC), propylene carbonate (PC), or the like, a linear carbonate such as diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), or the like.
[0040] In other embodiments, the electrolyte may be omitted or replaced. For example, if a solid electrolyte based on an inorganic material is used, a liquid or gel-like electrolyte may be omitted.
[0041] The secondary battery 100 based on some embodiments may include a cover plate 130.
[0042] The cover plate 130 may be shaped to close the opening 111. In one example, the cover plate 130 has a rectangular plate shape that matches that of the opening 111. The cover plate 130 may be coupled to the housing 110 to seal the interior of the housing 110 in which the electrode assembly 120 is disposed. In some embodiments, the cover plate 130 may be welded to the housing 110 by ultrasonic welding, laser welding, or the like. An electrode terminal 151 (see Fig. 3) may be disposed on the cover plate 130, and the electrode terminal 151 may be electrically connected to the first tab 121a or the second tab 123a of the electrode assembly 120.
[0043] The cover plate 130 may include an electrolyte injection port 133. The electrolyte injection port 133 may be used to inject the electrolyte into the interior of the housing 110. In some embodiments, the electrolyte injection port 133 may be arranged in a central region of the cover plate 130, but a position of the electrolyte injection port 133 may be changed in various ways and is not necessarily limited to the example. The electrolyte injection port 133 may be properly sealed after undergoing electrolyte injection, a forming process, or the like. In some embodiments, the electrolyte injection port 133 may be sealed by press-fitting a spherical sealing member formed of a polymer resin. Additional features of the cover plate 130 will be described with reference to other drawings.
[0044] The secondary battery 100 based on some embodiments may include a first terminal portion 150A and a second terminal portion 150B. Both the first terminal portion 150A and the second terminal portion 150B may be disposed on the cover plate 130. The first terminal portion 150A may be electrically connected to the first tab 121a of the electrode assembly 120, and the second terminal portion 150B may be electrically connected to the second tab 123a of the electrode assembly 120. Additional features of the first and second terminal portions 150A and 150B will be described with reference to other drawings.
[0045] Hereinafter, a short-circuit function and an internal gas emission function for ensuring stability of the secondary battery 100 will be described with reference to Fig. 3 to Fig. 15. A guide member 160, a short-circuit member 170, an elastic member 180, and the like, which will be described below, may be installed in a form in which they are electrically connected to the first terminal portion 150A or the second terminal portion 150B. The former may have a form in which they are electrically connected to the first current collecting member 124. The latter may have a form in which they are electrically connected to the second current collecting member 125. Except for the components described above, descriptions of other components may be the same or similar. Accordingly, for the sake of simplicity, a case in which the components described above are installed in a form in which they are electrically connected to the second terminal portion 150B will be mainly described.
[0046] Fig. 3 is a schematic exploded perspective view of elements in Fig. 2 illustrated section “II”. Fig. 3 mainly represents the Fig. 2. For simplicity, the second terminal portion 150B will be referred to as a terminal portion 150, and the second current collector element 125 will be referred to as a current collector element 125.
[0047] With reference to Fig. 3, the secondary battery 100 based on some embodiments may include a case 110, a cover plate 130, an insulating member 140, a terminal portion 150, a guide member 160, and a short-circuit member 170.
[0048] The housing 110 has been described above, and thus a repeated description thereof is omitted.
[0049] The cover plate 130 may be coupled to the housing 110 to seal the opening 111 of the housing 110, as described above. A first connection hole 131 may be formed in the cover plate 130. In addition, a first vent hole 132 may be further formed in the cover plate 130. The first vent hole 132 may serve as a path through which gas generated in the housing 110 is expelled to the outside, so that the gas inside the housing 110 can be released outside the housing 110.
[0050] The insulating member 140 may be disposed at a lower portion of the cover plate 130 and may insulate the cover plate 130 and the electrode terminal 151 from each other, thereby preventing unnecessary electrical short circuits from occurring. A material included in the insulating member 140 may be a material having insulating properties and is not limited. A second terminal hole 141 may be formed in the insulating member 140. A position of the second terminal hole 141 may be formed to coincide with that of the first terminal hole 131 formed in the cover plate 130.That is, in a state where the insulating member 140 is disposed at a lower portion of the cover plate 130, the first terminal hole 131 and the second terminal hole 141 may be formed to coincide with each other by being aligned with each other, so that the aligned first terminal hole 131 and second terminal hole 141 together form a through hole for receiving the electrode terminal 151. A second drain hole 142 may be additionally formed in the insulating member 140. In this case, a position of the second drain hole 142 may be formed to coincide with or align with that of the first drain hole 132 formed in the cover plate 130.That is, in the state where the insulating member 140 is disposed at the lower portion of the cover plate 130, the first vent hole 132 and the second vent hole 142 may be formed to coincide with each other by being aligned with each other, so that the aligned first vent hole 132 and second vent hole 142 together form a vent hole to allow the gas generated inside the housing 110 to be released outside the housing 110. In addition, the second vent hole 142 may be formed to have a diameter larger than that of the first vent hole 132. Accordingly, in the state where the insulating member 140 is disposed at the lower portion of the cover plate 130, in a view of the second vent hole 142 from below, a region adjacent to the first vent hole 132 and the first vent hole 132 of the cover plate 130 may be exposed at an edge of the second vent hole 142.In addition, an interior space S1 of the insulating member 140 communicating with the second vent hole 142 may include a first space S11 having a diameter equal to or similar to that of the second vent hole 142 and a second space S12 having a diameter larger than that of the second vent hole 142. The two spaces S11 and S12 may communicate with each other to form a single space S1. However, a wall portion 143 (see FIG. Fig. 5) be formed so that it is adjacent to the second drain hole 142 due to a diameter difference between the two spaces S11 and S12. In this case, the wall portion 143 may have a side surface 143a toward the first space S11 and a bottom surface 143b toward the second space S12 (see Fig. 5 to Fig. 7).
[0051] The terminal portion 150 may include an electrode terminal 151, a seal 152, and a current collector element 125.
[0052] The electrode terminal 151 may pass through the cover plate 130 and be coupled to the cover plate 130 to protrude and extend to an upper and lower portion of the cover plate 130 in a predetermined length. In particular, with respect to Fig. 3, the electrode terminal 151 sequentially passes through the first terminal hole 131 formed in the cover plate 130 and the second terminal hole 141 formed in the insulating member 140, and couples them. The electrode terminal 151 is illustrated as having a rod shape with a thread formed on an outer periphery thereof, but the disclosed technology is not limited to this. The electrode terminal 151 may be coupled to the current collector member 125 below the cover plate 130 to electrically couple to the electrode assembly 120. A coupling method is not limited, and, for example, a method such as riveting or caulking may be applied thereto. The electrode terminal 151 may be selected from copper, a copper alloy, an aluminum alloy, and the equivalent thereof depending on a polarity thereof, but the disclosed technology is not limited to this.For example, in a case where the current collecting element 125 functions as a negative electrode, the electrode terminal 151 connected thereto may be selected from copper, a copper alloy, and an equivalent thereof, but the disclosed technology is not limited thereto.
[0053] The electrode terminal 151 may include a flange portion 151b shaped to extend from one side of a body thereof in a horizontal direction. An upper body portion 151a, which corresponds to an upper portion of the body with respect to the flange portion 151b, may be exposed to an upper region of the cover plate 130 when the electrode terminal 151 is coupled to the cover plate 130. A lower body portion 151c, which corresponds to a lower portion of the body with respect to the flange portion 151b, may be coupled to the cover plate 130, the insulating member 140, the current collecting member 125, and the like without being exposed to the outside.
[0054] The seals 152 may be arranged between the first terminal hole 131 and the second terminal hole 141, which correspond to each other. The seal 152 may seal a space between the electrode terminal 151 and the cover plate 130, and a space between the electrode terminal 151 and the insulating member 140. The seal 152 may prevent external moisture from entering the secondary battery 100 or may prevent an electrolyte stored in the secondary battery 100 from flowing out.
[0055] In one embodiment, the gasket 152 may include a first gasket 152a and a second gasket 152b. The first gasket 152a may include a first body 152aa inserted from above the first terminal hole 131 and a first extension portion 152ab shaped to extend from an upper end of the first body 152aa in the horizontal direction to seal a space between the electrode terminal 151 and the cover plate 130. In this case, although not shown in the drawings, a recess portion that receives the flange portion 151b of the electrode terminal 151 may be formed in the first extension portion 152ab. The recess portion may prevent rotation of the flange portion 151b to stably fix the electrode terminal 151.The second gasket 152b may include a second body 152ba inserted from below the first terminal hole 131 and a second extension portion 152bb shaped to extend from a lower end of the second body 152ba in the horizontal direction to seal a space between the electrode terminal 151 and the cover plate 130. A recess portion 141a accommodating the second extension portion 152bb of the second gasket 152b may be formed in the second terminal hole 141 of the insulating member 140. The recess portion 141a may accommodate the second extension portion 152bb of the second gasket 152b to prevent rotation of the second extension portion 152bb, thereby stably fixing the second gasket 152b to the insulating member 140.
[0056] The current collector element 125 may be electrically connected to the electrode assembly 120 and installed in the housing 110 as described above. In this case, if the cover plate 130 has a first electrical polarity, the current collector element 125 may have a second electrical polarity different from the first polarity (e.g., opposite to the first electrical polarity) to ensure a desired direction of the electrical current. For example, the cover plate 130 may have a positive electrical polarity and the current collector element 125 may have a negative electrical polarity, or vice versa. Although not shown in the drawings, the current collector element 125 may be electrically connected to a fuse portion (not shown). For example, the fuse portion may be disposed on the current collector element 125.If the current collector element 125 overheats above a preset temperature, the fuse section may melt to block current flow. The fuse section may be implemented in a variety of ways, including fuse designs commonly used in the present technical field.
[0057] The guide member 160 may be installed in a lower portion of the second vent hole 142. Specifically, the guide member 160 may be installed in the second space S12 of the insulating member 140. The guide member 160 may be formed of a conductive material, and the type of material is not limited.
[0058] The short-circuit element 170 can be movably disposed in the guide element 160 so that the short-circuit element 170 can move in position relative to the guide element 160. The short-circuit element 170 can be in contact with the guide element 160 and electrically connected thereto. Like the guide element 160, the short-circuit element 170 can be formed from a conductive material, and the material type is not limited. The guide element 160 and the short-circuit element 170 can be formed from the same type of conductive material or from different types of conductive material.
[0059] The secondary battery 100 based on some embodiments may further include an elastic member 180. The elastic member 180 may be installed in the guide member 160 above the short-circuiting member 170 to push the short-circuiting member 170 from above. For example, the elastic member 180 may include a spring. In this case, physical properties, such as a spring force of the spring, may have a predefined or preset range.
[0060] The guide element 160, the short-circuit element 170 and the elastic element 180 will be described in more detail with reference to other drawings. In connection therewith, Fig. 4 is a cross-sectional view of a guide member 160, a short-circuit member 170, and an elastic member 180 coupled together in a secondary battery based on an embodiment of the disclosed technology, in which the short-circuit member 170, together with the elastic member 180 located within the guide member 160 and on the short-circuit member 170, is placed in contact with, and movably within the guide member 160. For simplicity, other components may be omitted from the drawings.
[0061] With reference to Fig. 4, the guide member 160 may include a first body 161 having a hollow structure having open upper and lower portions, and a first lower portion 162 shaped to extend from a lower end of the first body 161 in an inward and outward direction. In this case, a portion of the first lower portion 162 shaped to extend from the lower end of the first body 161 in an outward direction may be electrically connected to the current collector member 125. A portion of the first lower portion 162 shaped to extend from the lower end of the first body 161 in an inward direction may support the short-circuit member 170. The interior of the first body 161 may serve as a movement path of gas generated in the housing 110, or the like.
[0062] The short-circuiting element 170 may include a second body 171 having a hollow structure with an open upper portion, a second lower portion 172 shaped to extend from a lower end of the second body 171 in an outward direction, and a breakable portion 173 formed in the second body 171. The short-circuiting element 170 may be inserted into the first body 161 of the guide member 160 to be movable within the first body 161 of the guide member 160, and may be supported by a portion of the first lower portion 162 formed on the inside of the lower end of the first body 161.A height of the short-circuiting member 170 may be set within a range in which an upper end of the short-circuiting member 170 does not contact a lower surface of the cover plate 130 when the short-circuiting member 170 is inserted into the guide member 160. In an example where the short-circuiting member 170 is inserted into the guide member 160, the height of the short-circuiting member 170 may be determined such that an upper end of the short-circuiting member 170 and an upper end of the guide member 160 approximately correspond to each other, but the disclosed technology is not limited thereto. The breakable portion 173 may be formed in the second body 171 parallel to the second lower portion 172. In the accompanying drawings, the breakable portion 173 is shown formed at an inner lower end of the second body 171, but the disclosed technology is not limited thereto.The breakable portion 173 may include a notch. The notch may be formed to cause the breakable portion 173 to break according to the internal pressure of the housing 110. The shape of the notch is not limited, and a notch shape commonly used in the present technical field may be adopted.
[0063] The elastic member 180 may be installed in a space provided between the inside of the first body 161 of the guide member 160 and the outside of the second body 171 of the short-circuit member 170. In this case, an upper portion of the elastic member 180 may be formed by the lower surface 143b of the wall portion 143 (see Fig. 5) of the insulating member 140, and a lower portion of the elastic member 180 may be supported by the second lower portion 172 of the short-circuit member 170.
[0064] Hereinafter, based on some embodiments, an operation of the short-circuit element 170 in the secondary battery 100 will be mainly described.
[0065] Fig. 5 to Fig. 7 are cross-sectional views of sequential operations of the short-circuit element 170 in the secondary battery 100 based on an embodiment of the disclosed technology.
[0066] With reference to Fig. 5, as described above, the guide member 160, the short-circuit member 170, and the elastic member 180 may be installed in a lower portion of the second vent hole 142 of the insulating member 140. In this case, the first lower portion 162 of the guide member 160 may be held in a state of being electrically connected to the current collector member 125. For example, the first lower portion 162 may be in a state of being in contact with or connected to the current collector member 125. The short-circuit member 170 may be held in a state of being pressed by the elastic member 180, and an upper end of the short-circuit member 170 may be held in a state of being spaced apart from a lower surface of the cover plate 130. The short-circuit member 170 may be electrically connected to the guide member 160.
[0067] With reference to Fig. 6, when the internal pressure of the housing 110 increases excessively, gas or the like generated in the housing 110 may flow into an open portion of a lower portion of the guide member 160. In this case, when a pressure such as gas or the like exceeds the force of the elastic member 180 pressing the short-circuit member 170, the short-circuit member 170 may start to move upward or rise due to the net pressure. Accordingly, this upward movement of the short-circuit member 170 causes the elastic member 180 to be compressed in proportion to the rise of the short-circuit member 170. Subsequently, as the pressure generated in the housing 110 increases, the movable short-circuit member 170 may continue to rise until an upper end of the short-circuit member 170 comes into contact with a lower surface of the cover plate 130 exposed to the second vent hole 142.Under this condition, all of the current collector element 125, the guide element 160, and the short-circuit element 170 may be electrically connected to each other. If the current collector element 125 and the cover plate 130 may be configured to have different electrical polarities, a short-circuit condition may be induced when the upper end of the short-circuit element 170 comes into contact with the lower surface of the cover plate 130. Furthermore, when the short circuit is induced, a large amount of current may temporarily flow through the short-circuit portion, thereby generating excessive heat. If the temperature of a fusible portion formed on the current collector element 125 or electrically connected to the current collector element 125 exceeds a melting temperature due to the generated heat, the fusible portion may melt to stop or block the flow of current.
[0068] With reference to Fig. 7 can, if the pressure generated in the housing 110 in the Fig. 6, the breakable portion 173 formed in the second body 171 of the short-circuit member 170 can be broken, and thus the internal gas can be discharged to the outside through the second discharge hole 142 and the first discharge hole 132.
[0069] In the above-described operation of the short-circuiting element 170, variables such as a length of the second body 171 of the short-circuiting element 170, physical properties such as a spring force of the elastic member 180, a melting temperature of the fusible portion formed on the current collector element 125, and a notch design for causing breakage of the breakable portion 173 can be adjusted so that a blow-up condition in the short-circuiting element 170, a short-circuiting condition, and a breakage condition of the breakable portion 173 can be set in advance.
[0070] Other embodiments of the short-circuit element 170 are described below.
[0071] Fig. 8 is a diagram illustrating another embodiment of the short-circuit element 170 in the secondary battery 100 based on an embodiment. Fig. 9 is a diagram illustrating another embodiment of the short-circuit element 170.
[0072] First, the short-circuit element 170 can be described with reference to Fig. 8 further includes a protrusion portion 174 coupled to an outer periphery of the second body 171. For example, the protrusion portion 174 may have an overall annular shape. A recess (not shown) may be formed in the outer periphery of the second body 171 to receive a portion of the protrusion portion 174. The protrusion portion 174 may be formed integrally with the second body 171. When the short-circuiting element 170 rises and the upper end of the short-circuiting element 170 comes into contact with the lower surface of the cover plate 130, the protrusion portion 174 may be received in a receiving recess 142a (see Fig. 10A and Fig. 10B) provided in the insulating member 140, thereby preventing the short-circuiting member 170 from sinking. An upper end of the protruding portion 174 may have an inclined surface 174a. In this case, when the short-circuiting member 170 rises, the protruding portion 174 cannot get caught in the wall portion 143 of the insulating member 140 (see Fig. 10A and Fig. 10B).
[0073] With reference to Fig. 9, at least one of the second body 171 or the protrusion portion 174 of the short-circuit element 170 may have at least one cutout portion 171a in a height direction. That is, the cutout portion 171a may be formed in the height direction in the second body 171, in the protrusion portion 174, or in both the second body 171 and the protrusion portion 174. In connection with this, Fig. 9 illustrates a case where the cutout portion 171a is formed both in the second body 171 and on the projection portion 174. In addition, Fig. 9 illustrates a case where one cutout portion 171a is formed, but two or more cutout portions 171a may be formed. The cutout portion 171a may allow the second body 171 or the protrusion portion 174 to be slightly reduced in size by external pressure, thereby allowing the protrusion portion 174 to be more easily received in the receiving groove 142a provided in the insulating member 140 when the short-circuiting member 170 rises.
[0074] Fig. 10A and Fig. 10B are cross-sectional views of operations of the short-circuit element 170 of Fig. 9. With reference to Fig. 10A, the insulating member 140 may include a receiving groove 142a formed in the side surface 143a of the wall portion 143. The receiving groove 142a may receive the protrusion portion 174 of the short-circuiting member 170 therein.
[0075] With reference to Fig. 10B, as described above, the short-circuiting element 170 can rise when the internal pressure of the housing 110 increases. In this case, the inclined surface 174a formed at the upper end of the protruding portion 174 can guide the protruding portion 174 from being caught in the wall portion 143 of the insulating member 140 when the short-circuiting element 170 rises. In addition, when the upper end of the short-circuiting element 170 rises until the upper end of the short-circuiting element 170 comes into contact with a lower surface of the cover plate 130, the protruding portion 174 can be received in the receiving groove 142a provided in the insulating member 140. Accordingly, the short-circuiting element 170 can be fixed in a raised state and cannot descend even when the internal pressure of the housing 110 decreases.When the short-circuit element 170 is fixed to the insulating member 140 in the raised state, the short-circuit element 170 can be prevented from repeatedly rising and falling based on an increase or decrease in the internal pressure of the housing 110, thereby performing a short-circuit function more stably.
[0076] Fig. 11 is a diagram illustrating another embodiment of the short-circuit element 170.
[0077] With reference to Fig. 11, the short-circuit element 170 may further include a protrusion portion 174 coupled to an outer periphery of the second body 171. In this case, the protrusion portion 174 may include a body portion 174b and an elastic protrusion portion 174c. The body portion 174b may be coupled to the outer periphery of the second body 171 and may have an overall annular shape. A recess (not shown) may be formed in the outer periphery of the second body 171 to receive at least a portion of the body portion 174b. The elastic protrusion portion 174c may be shaped to extend from an upper end of the body portion 174b in a downward direction to be slightly inclined. A plurality of elastic protrusion portions 174c may be formed as in Fig. 11, may be formed at equal intervals along the body portion 174b, or the number of elastic protrusion portions 174c may be formed to be larger or smaller than that shown in Fig. 11. The elastic protrusion portion 174c can be elastically deformed by an external force in a direction closer to the body portion 174b and can be elastically restored when the external force disappears. The elastic protrusion portion 174c can allow the protrusion portion 174 to be received in the receiving groove 142a provided in the insulating member 140 more easily than in other embodiments when the short-circuiting element 170 pops up.
[0078] Fig. 12A, Fig. 12B and Fig. 12C are cross-sectional views of operations of the short-circuit element 170 of Fig. 11. With reference to Fig. 12A, the insulating member 140 may have a receiving groove 142a formed in the side surface 143a of the wall portion 143. The receiving groove 142a may receive the protrusion portion 174 of the short-circuiting member 170 therein. The elastic protrusion portion 174c of the protrusion portion 174 may retain an initial shape thereof. Referring to Fig. 12B, the short-circuiting element 170 may rise when the internal pressure of the housing 110 increases. In this case, the elastic protrusion portion 174c of the protrusion portion 174 may be formed to extend from an upper end of the body portion 174b in a downward direction to be inclined. Thus, when the short-circuiting element 170 rises, the protrusion portion 174 may be guided so as not to be caught in the wall portion 143 of the insulating member 140. In addition, the elastic protrusion portion 174c may be pressed by the wall portion 143 to be elastically deformed in a direction closer to the body portion 174b. Referring to Fig. 12C, when an upper end of the short-circuiting member 170 rises until the upper end of the short-circuiting member 170 comes into contact with a lower surface of the cover plate 130, the elastic protrusion portion 174c of the protrusion portion 174 may be positioned in the receiving groove 142a of the insulating member 140. In addition, when an external force applied to the elastic protrusion portion 174c is released, the elastically deformed shape of the elastic protrusion portion 174c may be restored to catch in the receiving groove 142a. Accordingly, as in other embodiments, the short-circuiting member 170 may be fixed in a raised state and may not descend even if the internal pressure of the casing 110 decreases.
[0079] The following describes a secondary battery based on another embodiment of the disclosed technology. The following examples may differ from the examples discussed above with respect to a guide member 260 and a short-circuit member 270, and other components in the subsequent examples may be the same or similar to those in the examples discussed above. Thus, the following mainly describes the guide member 260 and the short-circuit member 270. In addition, components in the subsequent examples may be the same or similar to those in the examples discussed above and may be denoted by the same reference numerals, and only the guide member 260 and the short-circuit member 270 are denoted by new reference numerals.
[0080] Fig. 13 to Fig. 15 are cross-sectional views of sequential operations of a short-circuit element 270 in a secondary battery based on another embodiment.
[0081] With reference to Fig. 13, a secondary battery 200 based on some embodiments may include a guide member 260, a shorting member 270, and a shorting tab 265. Additionally, the secondary battery 200 may further include an elastic member 280.
[0082] The guide member 260 may be installed in a lower portion of a second drain hole 142. Specifically, the guide member 260 may be installed in a second space S12 of an insulating member 140. In this case, unlike the examples discussed above, the guide member 260 may not be formed of a conductive material. The guide member 260 may include a first body 261 having a hollow structure having open upper and lower portions, and a first lower portion 262 shaped to extend from a lower end of the first body 261 in an inward direction. That is, unlike the examples discussed above, in some embodiments, the first lower portion 262 of the guide member 260 may be shaped to extend from the lower end of the first body 261 only in the inward direction.Additionally, the first lower portion 262 may not be connected to a current collector element 125. As in the examples discussed above, the first lower portion 262 may be shaped to extend from the lower end of the first body 261 in an inward and outward direction. A portion of the first lower portion 262 shaped to extend from the lower end of the first body 261 in the inward direction may support the short-circuit element 270. The interior of the first body 261 may serve as a movement path for gas generated in the housing 110, or the like.
[0083] The short-circuit element 270 may include a second body 271 having a hollow structure with an open upper portion, a second lower portion 272 shaped to extend from a lower end of the second body 271 in an outward direction, and a breakable portion 273 formed in the second body 271. A shape of the short-circuit element 270 may be the same as or similar to that in the examples discussed above.
[0084] As in the examples discussed above, the elastic member 280 may be installed in a space provided between the inside of the first body 261 of the guide member 260 and the outside of the second body 271 of the short-circuit member 270. In this case, an upper portion of the elastic member 280 may be supported by a lower surface of a wall portion 143 of the insulating member 140, and a lower portion of the elastic member 280 may be supported by the second lower portion 272 of the short-circuit member 270.
[0085] The shorting tab 265 may be formed of a conductive material, and a material type is not limited. The shorting tab 265 may have one end coupled to a lower portion of the shorting element 270, and the other end may be positioned in a lower portion of the current collector element 125. As shown in Fig. 13 to Fig. 15, in one example, the shorting tab 265 may include a vertical member 265a coupled to the lower portion of the shorting member 270, the vertical member 265a extending a predetermined length in a downward direction, and a horizontal member 265b extending from a lower portion of the vertical member 265a a predetermined length toward the current collector member 125. In this case, the vertical member 265a and the horizontal member 265b may be integrally formed.
[0086] As in Fig. 13 to Fig. 15, the vertical member 265a may be disposed at an open lower portion of the guide member 260 to be coupled to the lower portion of the short-circuit member 270. Alternatively, unlike in the drawings, an opening (not shown) through which the vertical member 265a passes may be formed in the first lower portion 262 of the guide member 260, and the vertical member 265a may pass through the opening to be coupled to the lower portion of the short-circuit member 270. The vertical member 265a may have a plate shape or a rod shape, but the disclosed technology is not limited thereto.
[0087] The horizontal member 265b may extend from the lower portion of the vertical member 265a in a horizontal direction toward the current collector member 125. The horizontal member 265a may also have a plate shape or a rod shape, but the disclosed technology is not limited thereto.
[0088] As in Fig. As shown in FIG. 13, the short-circuiting member 270 may maintain a state in which the short-circuiting member 270 is pressed by the elastic member 280, and an upper end of the short-circuiting member 270 may be maintained in a state of being spaced apart from a lower surface of the cover plate 130. In this case, a distance (denoted by "h1") between the upper end of the short-circuiting member 270 and the lower surface of the cover plate 130 may be approximately equal to a distance (denoted by "h2") between a lower surface of the current collector member 125 and the horizontal member 265b of the short-circuiting tab 265.
[0089] With reference to Fig. 14, when an internal pressure of a housing increases excessively, the short-circuiting element 270 may begin to rise as in the examples discussed above, and the elastic member 180 may be compressed in proportion to the rise of the short-circuiting element 270. Subsequently, as the pressure generated in the housing 110 increases, the short-circuiting element 270 may rise until an upper end of the short-circuiting element 270 comes into contact with a lower surface of the cover plate 130 exposed to the second vent hole 142. Furthermore, when the upper end of the short-circuiting element 270 comes into contact with the lower surface of the cover plate 130, the horizontal member 265b of the short-circuiting tab 265 may come into contact with the current collector element 125.In this case, all of the current collector element 125, the shorting tab 265, and the shorting element 270 may be electrically connected to each other, and the current collector element 125 and the cover plate 130 may have different polarities. Thus, the upper end of the shorting element 270 may come into contact with the lower surface of the cover plate 130, and a short circuit may be caused when the shorting tab 265 comes into contact with the current collector element 125. Furthermore, when the short circuit is caused, a large amount of current may temporarily flow, thereby generating excessive heat. In this case, if the temperature of the fusible portion formed on the current collector element 125 or electrically connected to the current collector element 125 exceeds a melting temperature due to the generated heat, the fusible portion may melt to block current flow.
[0090] With reference to Fig. 15 can, if the pressure generated in the housing in the Fig. 14, the breakable portion 273 formed in the second body 271 of the short-circuit member 270 can be broken, and thus the internal gas can be discharged to the outside through the second discharge hole 142 and the first discharge hole 132.
[0091] As mentioned with reference to Fig. 8 to Fig. 12C, the short-circuit element 270 based on some embodiments may further include a protrusion portion (not shown) coupled to an outer periphery of the second body 271. Various embodiments of the protrusion portion have been described above, and thus a repeated description thereof will be omitted. As described with reference to Fig. 8 to Fig.12C, the insulating member 140 based on some embodiments may have a receiving groove for receiving the protrusion portion, and a repeated description thereof will be omitted.
[0092] As described above, the secondary battery 100 based on embodiments of the disclosed technology may include the short-circuiting elements 170 and 270 that perform a short-circuiting function when an abnormality occurs, and frangible portions 173 and 273 formed in the short-circuiting element, wherein the frangible portions 173 and 273 perform an internal gas emission function, so that components that perform corresponding functions do not need to be additionally installed, thereby simplifying a configuration.
[0093] Only specific examples of implementations of particular embodiments are described. Variations, improvements, and enhancements to the disclosed embodiments and other embodiments may be made based on the disclosure of this patent document.
[0094] A secondary battery includes a casing that houses an electrode assembly; a cover plate that seals an opening of the casing and includes a first drain hole and has a first polarity; an insulating member disposed at a lower portion of the cover plate and includes a second drain hole with a larger diameter than the first drain hole and positioned to coincide with the first drain hole; a current collector member disposed at a lower portion of the insulating member and electrically connected to the electrode assembly and having a second polarity different from the first polarity; a guide member disposed in a lower portion of the second drain hole and electrically connected to the current collector member;and a short-circuiting element containing a conductive material and disposed in the guide member to move in response to pressure generated within the housing to come into contact with the cover plate;
Claims
[1] Secondary battery (100, 200), comprising: a housing (110) structured to receive an electrode assembly (120); a cover plate (130) configured to seal an opening (111) of the housing (110) and including a first vent hole (132) to allow a gas to pass therethrough, the cover plate (130) having a first electrical polarity for the secondary battery; an insulating member (140) disposed at a lower portion of the cover plate (130) and including a second vent hole (142) positioned to coincide with a position of the first vent hole (132) to allow the gas to pass through the first and second vent holes (142), the second vent hole (142) having a larger diameter than the first vent hole (132); a current collector element (124, 125) disposed on a lower portion of the insulating member (140) and electrically connected to the electrode assembly (120), the current collector element (124, 125) having a second electrical polarity of the secondary battery (100, 200) different from the first electrical polarity; a guide member (160, 260) disposed in a lower portion of the second drain hole (142) and electrically connected to the current collector member (124, 125); and a short-circuit element (170, 270) containing a conductive material and movably disposed in the guide element (160, 260), wherein the short-circuit element (170, 270) is configured to move upward in response to pressure generated within the housing (110) to come into contact with the cover plate (130). [2] Secondary battery (100, 200) according to claim 1, further comprising: an elastic element (180, 280) arranged in the guide element (160, 260) and configured to press against the short-circuit element (170, 270) from above to counteract the pressure generated within the housing (110). [3] A secondary battery (100, 200) according to claim 1 or claim 2, wherein the guide member (160, 260) includes: a first body (152a, 161, 261) including an open upper and lower portion; and a first lower portion (162, 262) shaped to extend from a lower end of the first body (152a, 161, 261) in both an inward and an outward direction, wherein the first lower portion (162, 262) is electrically connected to the current collector element (124, 125). [4] Secondary battery (100, 200) according to one of the preceding claims, wherein the short-circuit element (170, 270) contains: a second body (152b, 171, 271) including an open upper portion; a second lower portion (172, 272) shaped to extend from a lower end of the second body (171, 271) in an outward direction; and a breakable portion (173, 273) formed in the second body (171, 271) and including a notch. [5] The secondary battery (100, 200) according to claim 4, wherein the short-circuit member (170, 270) further includes a protrusion portion (174, 174c) coupled to an outer periphery of the second body (152b, 171, 271), and the insulating member (140) includes a receiving groove (142a) structured to receive the protrusion portion (174, 174c) when the short-circuit member (170, 270) moves upward. [6] The secondary battery (100, 200) according to claim 5, wherein at least one of the second body (152b, 171, 271) or the protrusion portion (174, 174c) of the short-circuit member (170, 270) includes at least one cutout portion. [7] The secondary battery (100, 200) according to claim 5 or claim 6, wherein the protruding portion (174, 174c) includes an inclined surface (174a) formed at an upper end of the protruding portion (174, 174c). [8] A secondary battery (100, 200) according to any one of claims 5 to 7, wherein the projection portion (174, 174c) includes: a body portion (174b) coupled to an outer periphery of the second body (152b, 171, 271); and an elastic projection portion (174c) extending from an upper end of the body portion (174b) in a downward direction at an angle. [9] Secondary battery (100, 200), comprising: a housing (110) structured to receive an electrode assembly (120); a cover plate (130) configured to seal an opening (111) of the housing (110) and including a first vent hole (132), the cover plate (130) having a first polarity; an insulating member (140) disposed at a lower portion of the cover plate (130) and including a second drain hole (142) positioned to coincide with a position of the first drain hole (132), the second drain hole (142) having a larger diameter than the first drain hole (132); a current collector element (124, 125) disposed at a lower portion of the insulating member (140) and electrically connected to the electrode assembly (120), the current collector element (124, 125) having a second polarity different from the first polarity; a guide member (160, 260) disposed in a lower portion of the second drain hole (142); a short-circuit element (170, 270) containing a conductive material and movably disposed in the guide element (160, 260), the short-circuit element (170, 270) being configured to move upward in response to a pressure generated within the housing (110) to come into contact with the cover plate (130); and a shorting tab (265) containing a conductive material and coupled to a lower portion of the shorting element (170, 270), the shorting tab (265) being configured to come into contact with the current collector element (124, 125) when the shorting element (170, 270) comes into contact with the cover plate (130). [10] Secondary battery (100, 200) according to claim 9, further comprising: an elastic element (180, 280) arranged in the guide element (160, 260) and configured to press against the short-circuit element (170, 270) from above. [11] A secondary battery (100, 200) according to claim 9 or claim 10, wherein the guide member (160, 260) includes: a first body (152a, 161, 261) including an open upper and lower portion; and a first lower portion (162, 262) shaped to extend from a lower end of the first body (152a, 161, 261) in an inward direction. [12] Secondary battery (100, 200) according to one of claims 9 to 11, wherein the short-circuit element (170, 270) includes: a second body (152b, 171, 271) including an open upper portion; a second lower portion (172, 272) shaped to extend from a lower end of the second body (152b, 171, 271) in an outward direction; and a breakable portion (173, 273) formed in the second body (152b, 171, 271) and including a notch. [13] The secondary battery (100, 200) according to claim 12, wherein the short-circuit member (170, 270) further includes a protrusion portion (174, 174c) coupled to an outer periphery of the second body (152b, 171, 271), and the insulating member (140) includes a receiving groove (142a) structured to receive the protrusion portion (174, 174c) when the short-circuit member (170, 270) moves upward. [14] The secondary battery (100, 200) according to claim 13, wherein at least one of the second body (171, 271) or the protrusion portion (174, 174c) of the short-circuit member (170, 270) includes at least one cutout portion. [15] The secondary battery (100, 200) according to claim 13 or claim 14, wherein the protruding portion (174, 174c) includes an inclined surface (174a) formed at an upper end of the protruding portion (174, 174c). [16] A secondary battery (100, 200) according to any one of claims 13 to 15, wherein the projection portion (174, 174c) includes: a body portion (174b) coupled to an outer periphery of the second body (171, 172); and an elastic projection portion (174, 174c) extending from an upper end of the body portion (174b) in a downward direction at an angle.