Secondary batteries

Abstract

An embodiment of the present invention may include a battery can with an open top and an internal housing space, a top cap covering the open top of the battery can, an electrode assembly located in the housing space, which is wound with a separator positioned between a positive electrode plate and a negative electrode plate and stacked in order, an electrode lead electrically connecting the electrode assembly to at least one of the battery can or the top cap, and a first fire extinguishing section containing a fire extinguishing component and located between the electrode assembly and the battery can.

Description

Technical Field

[0005] ,

[0004] , , ,

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0095641 filed on July 21, 2023 and Korean Patent Application No. 10-2024-0089909 filed on July 8, 2024, and all the contents disclosed in the documents of the Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a secondary battery having a fire extinguishing function.

Background Art

[0003] In order to solve environmental pollution caused by the use of petroleum resources and the shortage problem of energy sources due to the depletion of petroleum resources, research and development on power generation based on environmentally friendly energy sources have been carried out. In particular, research on secondary batteries, which are highly utilized because they can be repeatedly charged and discharged, has been actively conducted, and research has been done on various aspects such as materials, structures, processes, and stability of secondary batteries. ​​​​​​To manufacture such a secondary battery, first, an electrode active material slurry is applied to the positive electrode current collector and the negative electrode current collector to produce the positive and negative electrodes. These are then stacked on both sides of a separator to form an electrode assembly of a predetermined shape. Finally, the electrode assembly is placed in a battery case, the electrolyte is injected, and then it is sealed.

[0006] Rechargeable batteries are classified into pouch type and can type, depending on the material of the case that houses the electrode assembly. Pouch type batteries house the electrode assembly in a pouch made of a flexible polymer material. Can type batteries house the electrode assembly in a case made of metal or plastic.

[0007] Can-type, or cylindrical, secondary batteries are manufactured by housing a wound jelly-roll shaped electrode assembly inside a battery can, followed by an activation process with an electrolyte. Furthermore, if the internal temperature or pressure rises due to internal defects or external factors, cylindrical secondary batteries can prevent secondary damage caused by the rise in temperature and pressure by interrupting the current with a current interruption device such as a PTC (Positive Temperature Coefficient) or CID (Current Interrupt Device).

[0008] However, if high-temperature flames and gases are generated in a secondary battery, cylindrical secondary batteries do not have separate fire extinguishing components, which can lead to the spread of high-temperature flames and gases to surrounding components, causing damage to spread. Therefore, there is a need for cylindrical secondary batteries equipped with fire extinguishing functions that can suppress high-temperature flames and gases. [Overview of the project] [Problems that the invention aims to solve]

[0009] One problem that this invention aims to solve is to provide a secondary battery equipped with a fire extinguishing function that effectively suppresses high-temperature flames and gases generated inside. [Means for solving the problem]

[0010] An embodiment of the present invention includes a battery can with an open top and an internal housing space, a top cap covering the open top of the battery can, an electrode assembly located in the housing space, which is wound with a separator positioned between a positive electrode plate and a negative electrode plate and stacked in order, an electrode lead electrically connecting the electrode assembly to at least one of the battery can or the top cap, and a first fire extinguishing section containing a fire extinguishing component and located between the electrode assembly and the battery can.

[0011] The first fire extinguishing unit may include a band form that encloses the outer surface of the electrode assembly.

[0012] The first fire extinguishing unit may include an upper cover portion that encloses the upper side of the electrode assembly and a lower cover portion that encloses the lower side of the electrode assembly.

[0013] The electrode leads include a positive electrode lead electrically connected to the positive electrode plate and a negative electrode lead electrically connected to the negative electrode plate. The positive electrode lead is connected to the upper surface of the electrode assembly and electrically connects the electrode assembly and the top cap. The negative electrode lead electrically connects the lower surface of the electrode assembly and the battery can. When the width of the upper cover portion is L1 and the distance between the upper cover portion and the lower cover portion is L3, L1 / L3 can be 0.5 to 3.

[0014] When the width of the lower cover portion is L2, L1 and L2 can be the same.

[0015] The electrode leads include a positive electrode lead electrically connected to the positive electrode plate and a negative electrode lead electrically connected to the negative electrode plate, wherein the positive electrode lead electrically connects the upper surface of the electrode assembly and the top cap, and the negative electrode lead electrically connects the upper surface of the electrode assembly and the battery can, and when the width of the upper cover portion is L1 and the width of the lower cover portion is L2, L1 / L2 can be 3 to 10.

[0016] The electrode leads include a positive electrode lead electrically connected to the positive electrode plate and a negative electrode lead electrically connected to the negative electrode plate. The positive electrode lead is connected to the upper surface of the electrode assembly and electrically connects the electrode assembly to the top cap. The negative electrode lead electrically connects the lower surface and side of the electrode assembly to the battery can. When the width of the upper cover portion is L1 and the width of the lower cover portion is L2, L1 / L2 can be 3 to 6.

[0017] The first fire extinguishing unit may include a band body that encloses the outer surface of the electrode assembly, and a fire extinguishing agent containing the fire extinguishing component, which is housed inside the band body.

[0018] The band body may include at least one material from among PP (Poly Propylene) or PE (Polyethylene).

[0019] The thickness of the first fire extinguishing section can be 0.5 mm to 2 mm.

[0020] An embodiment of the present invention includes a battery can with an open top and an internal storage space, a top cap covering the open top of the battery can, an electrode assembly located in the storage space, which is wound up with a separator positioned between a positive electrode plate and a negative electrode plate and stacked in order, and having an electrode lead electrically connecting the electrode assembly to at least one of the battery can or the top cap, and a second fire extinguishing section containing a fire extinguishing component and located between the upper side of the electrode assembly and the top cap.

[0021] A first current interruption part that is located above the electrode assembly body, is connected to the electrode lead, and breaks when the pressure inside the battery can increases to interrupt the current flowing inside; and a second current interruption part that is located between the first current interruption part and the top cap and interrupts the current flowing inside when the temperature increases can be further included. The second fire extinguishing part can include a lower fire extinguishing member located in the space between the first current interruption part and the second current interruption part, and an upper fire extinguishing member located between the top cap and the second current interruption part.

[0022] The lower fire extinguishing member can adhere to the upper surface of the first current interruption part facing the second current interruption part.

[0023] The lower fire extinguishing member can adhere to a portion of the first current interruption part that has relatively low rigidity.

[0024] The lower fire extinguishing member can include a fire extinguishing body that adheres to the first current interruption part, and a liquid fire extinguishing agent that is accommodated inside the fire extinguishing body in a liquid state and contains a fire extinguishing component.

[0025] The lower fire extinguishing member can adhere to the upper surface of the first current interruption part by a taping method.

[0026] The upper fire extinguishing member can include a solid form and a material that vaporizes when the temperature increases.

[0027] The separator is composed of a plurality of layers, and the fire extinguishing part can further include a third fire extinguishing part laminated between the plurality of layers of the separator.

Advantages of the Invention

[0028] According to a preferred embodiment of the present invention, by effectively suppressing the high-temperature flames and gases generated inside, it is possible to prevent in advance the problems that the internal components are damaged or the flames and gases propagate.

[0029] In addition, the present invention may include effects that can be easily predicted by those skilled in the art from the configuration of preferred embodiments. [Brief explanation of the drawing]

[0030] The following drawings accompanying this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described later, serve to further illustrate the technical concept of the present invention. The present invention should not be construed as being limited solely to the matters described in such drawings.

[0031] [Figure 1] This is a cross-sectional view of a secondary battery according to Embodiment 1 of the present invention. [Figure 2] This is a perspective view of an electrode assembly according to Embodiment 1 of the present invention. [Figure 3] This is a perspective view showing the first fire extinguishing unit according to Embodiment 1 of the present invention enclosing the electrode assembly. [Figure 4] This is a cross-sectional view of a secondary battery according to Embodiment 2 of the present invention. [Figure 5] This is a cross-sectional view showing the increase in the internal pressure of a secondary battery according to Embodiment 2 of the present invention. [Figure 6] This is a cross-sectional view showing how the first current interruption section of the secondary battery according to Embodiment 2 of the present invention has broken due to an increase in internal pressure. [Figure 7] This is a cross-sectional view showing how the second current interruption unit has detached from the battery case due to an increase in the internal pressure of the secondary battery according to Embodiment 2 of the present invention. [Figure 8] This is a perspective view showing the first fire extinguishing unit according to Embodiment 3 of the present invention enclosing the electrode assembly. [Figure 9] This is a perspective view showing yet another configuration in which the first fire extinguishing unit according to Embodiment 3 of the present invention encloses the electrode assembly. [Figure 10] This is a cross-sectional view of the third fire extinguishing section and separator according to Embodiment 4 of the present invention. [Modes for carrying out the invention]

[0032] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention can be realized in a variety of different forms and is not limited to or restricted by the following embodiments.

[0033] In order to clearly explain the present invention, detailed descriptions of relevant prior art that are irrelevant to the description or that could obscure the gist of the invention have been omitted. In this specification, when assigning reference numerals to components in the drawings, the same or similar reference numerals are used throughout the specification for components that are the same or similar.

[0034] Furthermore, the terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather should be interpreted in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors may define the concepts of terms as appropriate to best describe their invention.

[0035] Embodiment 1 Figure 1 is a cross-sectional view of a secondary battery 1 according to Embodiment 1 of the present invention. Figure 2 is a perspective view of an electrode assembly according to Embodiment 1 of the present invention. Figure 3 is a perspective view of the first fire extinguishing section enclosing the electrode assembly according to Embodiment 1 of the present invention.

[0036] Referring to Figure 1, a secondary battery 1 according to one embodiment of the present invention can store electrical energy or output the stored electrical energy as designed and required. For example, the secondary battery 1 can house an electrode assembly 12 in the form of a jelly-roll, which will be described later.

[0037] Furthermore, if the internal temperature or pressure of the secondary battery 1 increases abnormally due to internal defects or external factors, it can prevent damage or ignition due to high temperature and high pressure by interrupting the current flowing inside.

[0038] Furthermore, the secondary battery 1 includes a configuration that performs a fire extinguishing function to suppress flames and gases when high-temperature flames and gases are generated inside, thereby preventing problems such as flames and gases transferring to other parts of the body.

[0039] Specifically, the secondary battery 1 may include a battery case 10, a top cap 11, an electrode assembly 12, electrode leads 13, and a first fire extinguishing section 140.

[0040] The battery casing 10 can be can-shaped and can form the outer surface of the secondary battery 1. Specifically, the battery casing 10 can be cylindrical. However, the shape of the battery casing 10 is not limited to a cylindrical shape and can be manufactured in various other shapes.

[0041] Furthermore, the battery can 10 can form an internal storage space, and the upper side of the battery can 10 can be open. Conversely, the lower side of the battery can 10 can be formed as a sealed structure.

[0042] The battery can 10 can be made of a lightweight conductive metal material such as aluminum, nickel, stainless steel, or an alloy thereof.

[0043] The top cap 11 can cover the open upper side of the battery can 10. That is, the top cap 11 can be formed on the upper side of the battery can 10 so that the internal space of the battery can 10 is sealed.

[0044] Figure 2 is a perspective view of the electrode assembly 12 according to Embodiment 1 of the present invention.

[0045] Referring to Figure 2, the electrode assembly 12 is located in the housing space of the battery can 10 and can store or output electrical energy through a chemical reaction. For example, the electrode assembly 12 can take the form of a jelly-roll. In other words, the electrode assembly 12 can take the form of being wound up with a separator 122 positioned between the positive electrode plate 120 and the negative electrode plate 121, and then stacked in sequence.

[0046] The positive electrode plate 120 and the negative electrode plate 121 can be manufactured by coating a metal current collector containing aluminum or copper with an active material slurry. Electrical energy can be stored or output from the electrode assembly 12 as lithium ions move between the positive electrode plate 120 and the negative electrode plate 121.

[0047] The electrode lead 13 can electrically connect the electrode assembly 12 to at least one of the battery can 10 or the top cap 11. In other words, the electrode lead 13 may include a negative electrode lead 131 that electrically connects the lower surface of the electrode assembly 12 to the inner lower surface of the battery can 10, and a positive electrode lead 130 that electrically connects the upper surface of the electrode assembly 12 to the inner lower surface of the top cap 11.

[0048] However, the structure of the electrode lead 13 is not limited to this, and the electrode lead 13 can be formed in various forms depending on the design, such as the positive electrode lead 130 and the negative electrode lead 131 both being formed on the upper surface of the electrode assembly 12, or the negative electrode lead 131 being formed on the side surface of the electrode assembly 12.

[0049] The electrode lead 13 can be connected to a portion of the electrode assembly 12 that is not coated with the active material slurry. For example, blank portions can be formed at the start and end ends of the positive electrode plate 120 and the negative electrode plate 121, based on the winding direction of the electrode plates, where the active material slurry is not applied. The electrode lead 13 can be welded to the blank portion.

[0050] The first fire extinguishing unit 140 contains fire extinguishing components and can perform fire extinguishing functions. For example, if high-temperature flames and gases are generated in the electrode assembly 12 due to internal bonding or external factors, the first fire extinguishing unit 140 can release specific fire extinguishing substances to suppress the flames and gases.

[0051] The first fire extinguishing unit 140 may contain a fire extinguishing material consisting of at least one component from among NH4H2PO4, NAHCO3, KHCO3, CO2, CF2ClBr, CF3Br, H2SO4, K2CO3, or Al2(SO4)3.

[0052] Figure 3 is a perspective view showing the first fire extinguishing unit 140, according to one embodiment of the present invention, enclosing the electrode assembly 12.

[0053] Referring to Figure 3, the first fire extinguishing section 140 can be formed to enclose the outer surface of the electrode assembly 12. For example, the first fire extinguishing section 140 can be located between the electrode assembly 12 and the battery can 10 and can enclose the side surface of the electrode assembly 12.

[0054] The first fire extinguishing section 140 may include a band form that encloses the outer surface of the electrode assembly 12. That is, the first fire extinguishing section 140 can be formed in a manner that encloses the side surface of the electrode assembly 12 and tightens the side surface of the electrode assembly 12.

[0055] The first fire extinguishing unit 140 may include a band body and a fire extinguishing agent.

[0056] The band body can wrap around the outer surface of the electrode assembly 12. For example, the electrode assembly 12 may be cylindrical, such as a jelly-roll shape, and the band body can wrap around the sides of the electrode assembly 12 along its periphery.

[0057] Furthermore, the band itself forms an internal storage space, allowing for the storage of the fire extinguishing agent described later.

[0058] The band body may be flexible and may include insulating materials. For example, the band body may include at least one material from PP (Polypropylene) or PE (Polyethylene). That is, the band body may not react electrically with the electrolyte contained inside the battery can 10.

[0059] The fire extinguishing agent is contained within the band body and may contain fire extinguishing components. For example, the fire extinguishing agent may be in powder form. Specifically, the fire extinguishing agent may consist of at least one component from among NH4H2PO4, NAHCO3, or KHCO3.

[0060] However, the components of the fire extinguishing agent are not limited to these, and can consist of various other components depending on the design and requirements.

[0061] The thickness of the first fire extinguishing section 140 can be between 0.5 mm and 2 mm. If the thickness of the first fire extinguishing section 140 is less than 0.5 mm, the first fire extinguishing section 140 may become considerably thinner and more susceptible to damage, or it may detach from the electrode assembly 12. Also, if the thickness of the first fire extinguishing section 140 is less than 0.5 mm, the first fire extinguishing section 140 may not be able to perform its fire extinguishing function adequately.

[0062] On the other hand, if the thickness of the first fire extinguishing section 140 exceeds 2 mm, a further space is formed between the electrode assembly 12 and the battery can 10, which can lead to a decrease in the energy density of the secondary battery 1 and a deterioration in the performance of the secondary battery 1. Also, if the thickness of the first fire extinguishing section 140 exceeds 2 mm, a further space is formed between the electrode assembly 12 and the battery can 10, and the electrode assembly 12 may be unstablely fixed inside the battery can 10.

[0063] As a result, if high-temperature flames and gases are generated from the electrode assembly 12, the first fire extinguishing unit 140 installed on the outer surface of the electrode assembly 12 will also ignite, and the fire extinguishing agent contained inside the first fire extinguishing unit 140 will leak out. The leaked fire extinguishing agent can perform its fire extinguishing function by suppressing the flames and gases.

[0064] Embodiment 2 Figure 4 is a cross-sectional view of a secondary battery according to Embodiment 2 of the present invention. Figure 5 is a cross-sectional view showing the increase in internal pressure of the secondary battery according to Embodiment 2 of the present invention. Figure 6 is a cross-sectional view showing the first current interruption section rupturing due to the increase in internal pressure of the secondary battery according to Embodiment 2 of the present invention. Figure 7 is a cross-sectional view showing the second current interruption section detaching from the battery case due to the increase in internal pressure of the secondary battery according to Embodiment 2 of the present invention.

[0065] The secondary battery according to Embodiment 2 of the present invention will be described below. The secondary battery according to Embodiment 2 of the present invention may include a second fire extinguishing section formed in a different manner than the first fire extinguishing section described in the secondary battery according to Embodiment 1. Details that overlap with the secondary battery according to Embodiment 1 described above will be omitted below.

[0066] Referring to Figure 4, the secondary battery according to Embodiment 2 of the present invention can include a fire extinguishing unit that can suppress high-temperature flames generated inside. Thus, the secondary battery according to Embodiment 2 of the present invention can include a second fire extinguishing unit 141.

[0067] The second fire extinguishing unit 141 contains fire extinguishing components and can perform fire extinguishing functions. For example, if high-temperature flames and gases are generated in the electrode assembly 12 due to internal bonding or external factors, the second fire extinguishing unit 141 can release specific fire extinguishing substances to suppress the flames and gases.

[0068] The second fire extinguishing unit 141 may contain a fire extinguishing material consisting of at least one component from among NH4H2PO4, NAHCO3, KHCO3, CO2, CF2ClBr, CF3Br, H2SO4, K2CO3, or Al2(SO4)3.

[0069] The second fire extinguishing section 141 may be located between the upper side of the electrode assembly 12 and the top cap 11. Specifically, the secondary battery 1 further includes a first current interruption section 15 and a second current interruption section 16 that interrupt the internal current in response to an increase in internal temperature or pressure, and the second fire extinguishing section 141 may be located in the region demarcated by the first current interruption section 15 and the second current interruption section 16.

[0070] More specifically, the first current interruption unit 15 can rupture when the pressure inside the battery can 10 increases, thereby interrupting the current flowing inside. For example, the first current interruption unit 15 can include a CID (Current Interrupt Device) filter.

[0071] Furthermore, the first current interruption section 15 is located above the electrode assembly 12 and can be connected to the electrode lead 13. That is, the first current interruption section 15 can contact the electrode lead 13 while being separated from the upper surface of the electrode assembly 12 by a predetermined distance. The first current interruption section 15 may include a structure that separates from the electrode lead 13 and breaks when the pressure inside the battery can 10 increases.

[0072] The second current interruption unit 16 can interrupt the current flowing inside the battery can 10 when the internal temperature of the battery can 10 increases. For example, the second current interruption unit 16 can include a PTC (Positive Temperature Coefficient). That is, when the internal temperature of the battery can 10 rises, the internal resistance of the second current interruption unit 16 increases, and the internal current of the second current interruption unit 16 can be interrupted.

[0073] The second current interruption section 16 can be located between the first current interruption section 15 and the top cap 11. For example, the second current interruption section 16 can be connected to the top cap 11 so as to form a space between the second current interruption section 16 and the top cap 11. Alternatively, a portion of the second current interruption section 16 can be separated from the first current interruption section 15 so as to form a space between the second current interruption section 16 and the first current interruption section 15.

[0074] The second fire extinguishing section 141 may include a lower fire extinguishing member 1410 located in the space between the first current interruption section 15 and the second current interruption section 16, and an upper fire extinguishing member 1411 located between the top cap 11 and the second current interruption section 16.

[0075] The lower fire extinguishing member 1410 can be attached to the upper surface of the first current interruption section 15 facing the second current interruption section 16. For example, the lower fire extinguishing member 1410 can be attached to the upper surface of the first current interruption section 15 by taping.

[0076] Specifically, the lower fire extinguishing member 1410 may include a fire extinguishing body that adheres to the first current interruption unit 15 and a liquid fire extinguishing agent contained inside the fire extinguishing body in a liquid state, which contains fire extinguishing components. For example, the liquid fire extinguishing agent may contain at least one component from among NAHCO3, H2SO4, K2CO3, or Al2(SO4)3.

[0077] The upper fire extinguishing member 1411 can be attached to the upper surface of the second current interruption section 16 facing the top cap 11. Alternatively, the upper fire extinguishing member 1411 can be attached to the lower surface of the top cap 11 facing the second current interruption section 16.

[0078] Thus, when the upper fire extinguishing member 1411 is integrally formed with the top cap 11 or the second current interruption unit 16, and the top cap 11 and the second current interruption unit 16 detach from the battery can 10 due to the high temperature and high pressure inside, the upper fire extinguishing member 1411 can detach from the battery can 10 together with the top cap 11 and the second current interruption unit 16.

[0079] Figure 5 is a cross-sectional view showing the increase in internal pressure of the secondary battery 1 according to one embodiment of the present invention, and Figure 6 is a cross-sectional view showing the rupture of the first current interruption section 15 due to the increase in internal pressure of the secondary battery 1 according to one embodiment of the present invention.

[0080] Referring to Figures 5 and 6, when gas is generated from the electrode assembly 12 and the pressure inside the battery can 10 increases, the first current interruption unit 15 can be pushed upward by the pressure inside the battery can 10. If the pressure inside the battery can 10 becomes even higher, a part of the first current interruption unit 15 may break, and the current flowing inside the first current interruption unit 15 may be interrupted.

[0081] In this case, the lower fire extinguishing member 1410 can adhere to a relatively less rigid portion of the first current interruption section 15. That is, when the pressure inside the battery can 10 increases, a rupture phenomenon occurs in the relatively less rigid portion of the first current interruption section 15, and the lower fire extinguishing member 1410 attached to that portion can also be subjected to external force and rupture.

[0082] In other words, with the fire extinguishing body attached to a relatively less rigid part of the first current interruption section 15, the relatively less rigid part of the first current interruption section 15 can rupture, causing the fire extinguishing body to rupture as well. Simultaneously, the liquid fire extinguishing agent contained inside the fire extinguishing body leaks out and flows into the ruptured section, allowing the liquid fire extinguishing agent to reach the electrode assembly 12.

[0083] As a result, when high-temperature flames and gases are generated from the electrode assembly 12 and the inside of the battery can 10 becomes hot and high-pressure, a temporary rupture occurs in the relatively less rigid part of the first current interruption section 15. Therefore, as soon as flames and gases are generated, the lower fire extinguishing member 1410 can immediately suppress the flames and gases.

[0084] Furthermore, since the lower fire extinguishing member 1410 contains a liquid fire extinguishing agent, the liquid fire extinguishing agent permeates the electrode assembly 12, allowing for more rapid suppression of flames and gases.

[0085] Figure 7 is a cross-sectional view showing how the second current interruption unit 16 detaches from the battery can 10 due to an increase in the internal pressure of the secondary battery 1 according to one embodiment of the present invention.

[0086] Referring to Figure 7, as the internal pressure of the battery can 10 increases, a rupture occurs in a part of the first current interruption section 15, allowing the top cap 11 and the second current interruption section 16 to detach from the battery can 10 as a single unit.

[0087] In this case, as described above, the upper fire extinguishing member 1411 can be detached from the battery can 10 together with the top cap 11 and the second current interruption unit 16. Furthermore, the upper fire extinguishing member 1411 may include a solid form and may include a material that vaporizes when the temperature increases.

[0088] As a result, with the structure and material characteristics of the upper fire extinguishing member 1411, when multiple secondary batteries 1 are provided to form a battery module, the upper fire extinguishing member 1411 can prevent the battery module from being damaged by fire.

[0089] Specifically, if a high-temperature flame and gas are generated in one of the multiple secondary batteries 1, the upper fire extinguishing member 1411 detaches from the battery can 10 and vaporizes, spreading as a gas inside the battery module. This prevents the high-temperature flame and gas from propagating, thus preventing secondary damage caused by the flame and gas.

[0090] Embodiment 3 The following describes the secondary battery 1 according to Embodiment 3 of the present invention. Unlike the secondary battery 1 according to Embodiment 1, the secondary battery 1 according to Embodiment 3 of the present invention may include a different structure of the first fire extinguishing unit 140. Details that overlap with the description of the secondary battery 1 according to Embodiment 1 above will be omitted below.

[0091] Figure 8 is a perspective view showing the first fire extinguishing unit enclosing the electrode assembly according to Embodiment 3 of the present invention. Figure 9 is a perspective view showing yet another view of the first fire extinguishing unit enclosing the electrode assembly according to Embodiment 3 of the present invention.

[0092] Referring to Figures 8 and 9, the first fire extinguishing section 140 may include a plurality of components that enclose the outer surface of the electrode assembly 12. For example, the first fire extinguishing section 140 may include a plurality of components that are formed to differ depending on the coupling configuration of the electrode assembly 12 and the electrode lead 13. Specifically, the first fire extinguishing section 140 may include an upper cover portion 1400 and a lower cover portion 1401.

[0093] The upper cover portion 1400 can enclose the upper side of the electrode assembly 12. The lower cover portion 1401 can enclose the lower side of the electrode assembly 12. That is, the lower cover portion 1401 is located below the upper cover portion 1400 and can be formed at a predetermined distance from the upper cover portion 1400.

[0094] Figure 8 is a perspective view showing the first fire extinguishing unit 140 enclosing the electrode assembly 12 according to another embodiment of the present invention.

[0095] Referring to Figure 8, the positive lead 130 is connected to the upper surface of the electrode assembly 12, and the electrode assembly 12 and the top cap 11 can be electrically connected. The negative lead 131 can be electrically connected to the lower surface of the electrode assembly 12 and the battery can 10.

[0096] When the width of the upper cover portion 1400 is L1 and the width of the lower cover portion 1401 is L2, L1 and L2 can be the same. In other words, since the ignition phenomenon mainly occurs in the portion of the electrode assembly 12 where the positive electrode lead 130 and the negative electrode lead 131 are joined, if the positive electrode lead 130 and the negative electrode lead 131 are formed to extend from the electrode assembly 12 in different directions, the secondary battery 1 according to the second embodiment can more effectively suppress flames and gases by designing the width of the upper cover portion 1400 and the width of the lower cover portion 1401 to be the same.

[0097] Furthermore, when the width of the upper cover portion 1400 is L1 and the distance between the upper cover portion 1400 and the lower cover portion 1401 is L3, L1 / L3 can be between 0.5 and 3. In other words, the upper cover portion 1400 and the lower cover portion 1401 can be separated from each other by a predetermined distance.

[0098] Specifically, if L1 / L3 is less than 0.5, the upper cover portion 1400 and the lower cover portion 1401 will be separated by a considerable distance, and the width of the upper cover portion 1400 and the lower cover portion 1401 will be narrowed, which may prevent the fire extinguishing function of the first fire extinguishing unit 140 from working properly. On the other hand, if L1 / L3 is greater than 3, the distance between the upper cover portion 1400 and the lower cover portion 1401 will be shortened, and most of the side surface of the electrode assembly 12 will be covered by the upper cover portion 1400 and the lower cover portion 1401, which may reduce the energy density of the secondary battery 1 and degrade the performance of the secondary battery 1.

[0099] Figure 9 is a perspective view showing the first fire extinguishing unit 140 enclosing the electrode assembly 12 according to another embodiment of the present invention.

[0100] Referring to Figure 9, the positive lead 130 can electrically connect the top surface of the electrode assembly 12 to the top cap 11, and the negative lead 131 can electrically connect the top surface of the electrode assembly 12 to the battery can 10. In other words, the positive lead 130 and the negative lead 131 can be connected to the same top surface of the electrode assembly 12.

[0101] As described above, since the ignition phenomenon mainly occurs in the portion of the electrode assembly 12 where the positive electrode lead 130 and the negative electrode lead 131 are connected, if the positive electrode lead 130 and the negative electrode lead 131 are connected to the upper surface, i.e., the upper side, of the electrode assembly 12, the width of the upper cover portion 1400 can be considerably larger than the width of the lower cover portion 1401.

[0102] Specifically, when the width of the upper cover portion 1400 is L1 and the width of the lower cover portion 1401 is L2, the ratio L1 / L2 can be between 3 and 10. If L1 / L2 is less than 3, the width of the upper cover portion 1400 becomes narrow, which may reduce the fire extinguishing function on the upper side of the electrode assembly 12 where the positive electrode lead 130 and negative electrode lead 131 are distributed. On the other hand, if L1 / L2 is greater than 10, the width of the upper cover portion 1400 becomes too wide, and the fire extinguishing function becomes concentrated only on the upper side of the electrode assembly 12, which may reduce the fire extinguishing function on the lower side of the electrode assembly 12.

[0103] Finally, when the positive electrode lead 130 is connected to the upper surface of the electrode assembly 12 and electrically connects the electrode assembly 12 to the top cap 11, and the negative electrode lead 131 electrically connects the lower surface and side of the electrode assembly 12 to the battery can 10, the width of the upper cover portion 1400 can be formed to be wider than the width of the lower cover portion 1401.

[0104] Specifically, when the width of the upper cover portion 1400 is L1 and the width of the lower cover portion 1401 is L2, the ratio L1 / L2 can be 3 to 6. This is because, since the negative electrode lead 131 is formed with a large contact area, the temperature of the positive electrode lead 130 becomes higher, causing ignition phenomena to occur more frequently. Therefore, it is preferable to design the width of the upper cover portion 1400 to be wider than the width of the lower cover portion 1401.

[0105] As a result, by designing the upper cover portion 1400 and the lower cover portion 1401 differently depending on the configuration of the electrode assembly 12 and the electrode lead 13, the first fire extinguishing unit 140 can perform its fire extinguishing function more effectively when high-temperature flames and gases are generated from the electrode assembly 12.

[0106] Embodiment 4 The following describes the secondary battery 1 according to Embodiment 4 of the present invention. Unlike the secondary battery 1 according to Embodiments 1 to 3, the secondary battery 1 according to Embodiment 4 may include a different fire extinguishing section structure. Details that overlap with the secondary battery 1 according to Embodiments 1 to 3 described above will be omitted below.

[0107] The secondary battery according to Embodiment 4 of the present invention may further include a third fire extinguishing section 142 designed in the separator 122.

[0108] Figure 10 is a cross-sectional view of the third fire extinguishing section 142 and separator 122 according to Embodiment 4 of the present invention.

[0109] Referring to Figure 10, the separator 122 consists of multiple layers, and the third fire extinguishing section 142 can be laminated between the multiple layers of the separator 122. That is, the third fire extinguishing section 142 can be coated on the inside of the separator 122 so as to be sealed between the multiple layers of the separator 122. In other words, the separator 122 can be wound up with the third fire extinguishing section 142 housed inside and become part of the electrode assembly 12.

[0110] As a result, with this structure of the third fire extinguishing unit 142, since the third fire extinguishing unit 142 is manufactured integrally with the separator 122 in a sealed state inside the separator 122, if high-temperature flames and gases are generated in a part of the electrode assembly 12, the third fire extinguishing unit 142 housed in the separator 122 can immediately perform its fire extinguishing function. Furthermore, since the third fire extinguishing unit 142 is manufactured integrally with the separator 122, there is the advantage that the separator 122 equipped with a fire extinguishing function can be designed more easily.

[0111] The above description is merely illustrative of the technical concept of the present invention, and any person with ordinary skill in the art to which the present invention belongs can make various modifications and alterations without departing from the essential characteristics of the present invention.

[0112] Therefore, the embodiments disclosed in this invention are for illustrative purposes only, and not to limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by such embodiments.

[0113] The scope of protection of this invention should be interpreted in accordance with the following claims, and all technical ideas within an equivalent scope should be interpreted as being included within the scope of the rights of this invention. [Explanation of Symbols]

[0114] 1 Secondary battery 10 Battery cans 11 Top cap 12 Electrode assembly 13 Electrode Leads 15. First current interruption section 16. Second current interruption section 120 Positive Plate 121 Negative plate 122 Separator 130 Positive Lead 131 Negative lead 140 First Fire Department 141 Second Fire Department 142 Third Fire Department 1400 Upper cover section 1401 Lower cover section 1410 Lower fire extinguishing member 1411 Upper fire extinguishing member

Claims

1. A battery can with an open top that forms an internal storage space, A top cap that covers the open upper side of the aforementioned battery can, The electrode assembly located in the aforementioned housing space includes a configuration in which a separator is positioned between the positive electrode plate and the negative electrode plate, and the electrodes are wound up and stacked in sequence, The electrode assembly and an electrode lead that electrically connects at least one of the battery can or the top cap, A secondary battery comprising a first fire extinguishing section containing a fire extinguishing component and located between the electrode assembly and the battery casing.

2. The secondary battery according to claim 1, wherein the first fire extinguishing section includes a band form that encloses the outer surface of the electrode assembly.

3. The First Firefighting Unit is, An upper cover portion that encloses the upper side of the electrode assembly, The secondary battery according to claim 2, further comprising a lower cover portion that encloses the lower side of the electrode assembly.

4. The electrode leads include a positive electrode lead electrically connected to the positive electrode plate and a negative electrode lead electrically connected to the negative electrode plate. The positive electrode lead is connected to the upper surface of the electrode assembly and electrically connects the electrode assembly and the top cap, and the negative electrode lead is connected to the lower surface of the electrode assembly and the battery can. The width of the upper cover portion is L １ The distance between the upper cover portion and the lower cover portion is L. ３ When that happens, L １ / L ３ The secondary battery according to claim 3, wherein the ratio is 0.5 to 3.

5. The width of the lower cover portion is L ２ When that happens, the L １ and L ２ The secondary battery described in claim 4 is identical to the secondary battery described in claim 4.

6. The electrode leads include a positive electrode lead electrically connected to the positive electrode plate and a negative electrode lead electrically connected to the negative electrode plate. The positive electrode lead electrically connects the upper surface of the electrode assembly and the top cap, and the negative electrode lead electrically connects the upper surface of the electrode assembly and the battery can. Let the width of the upper cover portion be L １ and the width of the lower cover portion be L ２ When this is the case, L １ / L ２ is 3 to 10. The secondary battery according to claim 3

7. The electrode leads include a positive electrode lead electrically connected to the positive electrode plate and a negative electrode lead electrically connected to the negative electrode plate. The positive electrode lead is connected to the upper surface of the electrode assembly and electrically connects the electrode assembly and the top cap, the negative electrode lead electrically connects the lower surface and side of the electrode assembly to the battery can, and the width of the upper cover portion is L １ The width of the lower cover portion is L ２ When that happens, L １ / L ２ The secondary battery according to claim 3, wherein the coefficients are 3 to 6.

8. The first fire extinguishing unit is, A band body that encloses the outer surface of the electrode assembly, The secondary battery according to claim 2, comprising a fire extinguishing agent containing the fire extinguishing component, which is housed inside the band body.

9. The secondary battery according to claim 8, wherein the band body comprises at least one material selected from PP (Polypropylene) or PE (Polyethylene).

10. The secondary battery according to claim 2, wherein the thickness of the first fire extinguishing section is 0.5 mm to 2 mm.

11. A battery can with an open top that forms an internal storage space, A top cap that covers the open upper side of the aforementioned battery can, The electrode assembly located in the aforementioned housing space includes a configuration in which a separator is positioned between the positive electrode plate and the negative electrode plate, and the electrodes are wound up and stacked in sequence, The electrode assembly and an electrode lead that electrically connects at least one of the battery can or the top cap, A secondary battery comprising a second fire extinguishing section containing a fire extinguishing component and located between the upper side of the electrode assembly and the top cap.

12. A first current interruption unit is located above the electrode assembly, connected to the electrode lead, and breaks when the pressure inside the battery can increases, thereby interrupting the current flowing inside. It further includes a second current interruption unit located between the first current interruption unit and the top cap, which interrupts the current flowing inside when the temperature increases. The second fire extinguishing unit is, A lower fire extinguishing member located in the space between the first current interruption section and the second current interruption section, The secondary battery according to claim 11, further comprising an upper fire extinguishing member located between the top cap and the second current interruption section.

13. The secondary battery according to claim 12, wherein the lower fire extinguishing member is attached to the upper surface of the first current interruption section facing the second current interruption section.

14. The secondary battery according to claim 13, wherein the lower fire extinguishing member is attached to a portion of the first current interruption section that has relatively low rigidity.

15. The aforementioned lower fire extinguishing member is The fire extinguishing body attached to the first current interruption section, The secondary battery according to claim 14, comprising a liquid fire extinguishing agent containing a fire extinguishing component, which is housed inside the fire extinguishing body in a liquid state.

16. The secondary battery according to claim 13, wherein the lower fire extinguishing member is attached to the upper surface of the first current interruption section by taping.

17. The secondary battery according to claim 12, wherein the upper fire extinguishing member includes a solid form and includes a material that vaporizes when the temperature increases.

18. The separator consists of multiple layers, The secondary battery according to any one of claims 1 to 17, wherein the fire extinguishing section further comprises a third fire extinguishing section laminated between a plurality of layers of the separator.

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