Secondary battery

Abstract

A secondary battery according to an embodiment of the present invention may comprise: a battery can which is open at the top thereof and within which an accommodation space is formed; a top cap which covers the open top of the battery can; an electrode assembly in which anode and cathode plates with separators interposed therebetween are wound so that the anode and cathode plates and the separators are successively stacked and which is disposed in the accommodation space; an electrode lead which electrically connects at least one of the battery can or the top cap to the electrode assembly; and a first fire-extinguishing part which contains a fire-extinguishing component and is disposed between the electrode assembly and the battery can.

Description

secondary battery

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0095641, filed July 21, 2023, and Korean Patent Application No. 10-2024-0089909, filed July 8, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a secondary battery having a digestive function.

[0005] To address environmental pollution caused by the use of petroleum resources and the resulting energy shortage resulting from their depletion, research and development are underway on power generation based on eco-friendly energy sources. In particular, active research is being conducted on secondary batteries, which offer high utility due to their ability to be repeatedly charged and discharged. Research is also being conducted on various aspects of secondary batteries, including their materials, structure, processes, and stability.

[0006] Common types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. These batteries are used in small products such as digital cameras, DVDs, MP3 players, mobile phones, PDAs, portable game devices, power tools, and e-bikes, as well as in larger products requiring high output, such as electric and hybrid vehicles, as well as power storage devices that store surplus generated power or renewable energy, and as backup power storage devices.

[0007] To manufacture these secondary batteries, first, an electrode active material slurry is applied to a positive electrode current collector and a negative electrode current collector to manufacture a positive electrode and a negative electrode, and these are laminated on both sides of a separator to form an electrode assembly of a predetermined shape. Then, the electrode assembly is housed in a battery case, filled with electrolyte, and sealed.

[0008] Secondary 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 materials such as metal or plastic.

[0009] Can-type, or cylindrical, secondary batteries are manufactured by housing a coiled jelly-roll-shaped electrode assembly within a battery can and then undergoing an activation process using an electrolyte. Furthermore, if the internal temperature or pressure increases due to internal defects or external factors, cylindrical secondary batteries can prevent secondary damage caused by increased temperature and pressure by interrupting the current through a current interrupting member, such as a PTC (Positive Temperature Coefficient) or CID (Current Interrupt Device).

[0010] However, when high-temperature flames and gases are generated from secondary batteries, cylindrical secondary batteries lack a separate fire extinguishing system. Consequently, these high-temperature flames and gases can spread to surrounding components, causing widespread damage. Therefore, there is a pressing need for cylindrical secondary batteries equipped with fire extinguishing capabilities capable of suppressing high-temperature flames and gases.

[0011] The problem to be solved by the present invention is to provide a secondary battery having a fire extinguishing function that effectively extinguishes high-temperature flames and gases generated internally.

[0012] A secondary battery according to an embodiment of the present invention comprises a battery can having an open upper side and forming a receiving space inside, a top cap covering the open upper side of the battery can, a separator positioned between a positive electrode plate and a negative electrode plate, which are wound and sequentially stacked, an electrode assembly positioned in the receiving space, an electrode lead electrically connecting the electrode assembly to at least one of the battery can or the top cap, and a first extinguishing unit including a extinguishing component and positioned between the electrode assembly and the battery can.

[0013] The above first digestive unit may include a band shape that wraps around the outer surface of the electrode assembly.

[0014] The first digestive unit may include an upper cover portion that surrounds an upper side of the electrode assembly and a lower cover portion that surrounds a lower side of the electrode assembly.

[0015] The electrode lead includes a positive lead electrically connected to the positive plate and a negative lead electrically connected to the negative plate, the positive lead is connected to the upper surface of the electrode assembly and electrically connects the electrode assembly and the top cap, the negative lead electrically connects the lower surface of the electrode assembly and the battery can, and when the width of the upper cover part is L1 and the distance between the upper cover part and the lower cover part is L3, L1 / L3 may be 0.5 to 3.

[0016] When the width of the lower cover portion is L2, L1 and L2 may be the same.

[0017] The electrode lead includes 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 connecting the upper surface of the electrode assembly and the top cap, and the negative electrode lead electrically connecting the upper surface of the electrode assembly and the battery can, and when the width of the upper cover part is L1 and the width of the lower cover part is L2, L1 / L2 may be 3 to 10.

[0018] The electrode lead includes a positive lead electrically connected to the positive plate and a negative lead electrically connected to the negative plate, the positive lead is connected to the upper surface of the electrode assembly and electrically connects the electrode assembly and the top cap, and the negative lead electrically connects the lower surface and the side surface of the electrode assembly to the battery can, and when the width of the upper cover part is L1 and the width of the lower cover part is L2, L1 / L2 may be 3 to 6.

[0019] The first fire extinguishing unit may include a band body that surrounds the outer surface of the electrode assembly and a fire extinguishing agent that is accommodated inside the band body and contains the fire extinguishing component.

[0020] The above band body may include at least one material among PP (Poly Propylene) material and PE (Polyethylene) material.

[0021] The thickness of the first digestive section may be 0.5 mm to 2 mm.

[0022] A secondary battery according to an embodiment of the present invention comprises a battery can having an open upper side and forming a receiving space inside, a top cap covering the open upper side of the battery can, a separator positioned between a positive electrode plate and a negative electrode plate, which are wound and sequentially stacked, an electrode assembly positioned in the receiving space, an electrode lead electrically connecting the electrode assembly and at least one of the battery can or the top cap, and a second fire extinguishing unit including a fire extinguishing component and positioned between the upper side of the electrode assembly and the top cap.

[0023] The battery can further include a first current blocking unit located on the upper side of the electrode assembly and connected to the electrode lead, which breaks when the pressure inside the battery can increases and blocks the current flowing inside, and a second current blocking unit located between the first current blocking unit and the top cap, which blocks the current flowing inside when the temperature increases.

[0024] The second fire extinguishing unit may include a lower fire extinguishing member positioned in a space between the first current blocking unit and the second current blocking unit, and an upper fire extinguishing member positioned between the top cap and the second current blocking unit.

[0025] The above lower digestion member can be attached to the upper surface of the first current blocking unit facing the second current blocking unit.

[0026] The above lower digestion member can be attached to a portion of the first current blocking section having relatively low rigidity.

[0027] The lower extinguishing member may include a extinguishing body attached to the first current cutoff portion and a liquid extinguishing agent contained in the extinguishing body in a liquid state and including a extinguishing component.

[0028] The above lower digestive member can be attached to the upper surface of the first current blocking member by taping.

[0029] The upper digestive member may include a solid form and may include a material that vaporizes when the temperature increases.

[0030] The above separation membrane is composed of a plurality of layers, and the digestion unit may further include a third digestion unit laminated between the plurality of layers of the separation membrane.

[0031] According to a preferred embodiment of the present invention, high-temperature flames and gases generated internally can be effectively suppressed, thereby preventing damage to the internal structure or the propagation of flames and gases in advance.

[0032] In addition, the configurations according to preferred embodiments of the present invention may include effects that can be easily predicted by those skilled in the art.

[0033] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0034] Figure 1 is a cross-sectional view of a secondary battery according to Example 1 of the present invention.

[0035] Figure 2 is a perspective view of an electrode assembly according to Example 1 of the present invention.

[0036] Figure 3 is a perspective view of the first digestive unit according to Example 1 of the present invention wrapping the electrode assembly.

[0037] Figure 4 is a cross-sectional view of a secondary battery according to Example 2 of the present invention.

[0038] Figure 5 is a cross-sectional view showing an increase in internal pressure of a secondary battery according to Example 2 of the present invention.

[0039] FIG. 6 is a cross-sectional view showing a state in which a first current interrupter is broken due to an increase in internal pressure of a secondary battery according to Example 2 of the present invention.

[0040] FIG. 7 is a cross-sectional view showing a second current blocking portion detached from the battery can as the internal pressure of the secondary battery according to Example 2 of the present invention increases.

[0041] Figure 8 is a perspective view of a first digestive unit according to Example 3 of the present invention wrapping an electrode assembly.

[0042] FIG. 9 is a perspective view of another embodiment of the first digestive unit according to the third embodiment of the present invention, in which the first digestive unit surrounds the electrode assembly.

[0043] Figure 10 is a cross-sectional view of the third digestion unit and separation membrane according to Example 4 of the present invention.

[0044] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0045] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0046] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0047]

[0048] Example 1

[0049]

[0050] Fig. 1 is a cross-sectional view of a secondary battery (1) according to Embodiment 1 of the present invention. Fig. 2 is a perspective view of an electrode assembly according to Embodiment 1 of the present invention. Fig. 3 is a perspective view of a first extinguishing unit according to Embodiment 1 of the present invention surrounding an electrode assembly.

[0051] Referring to FIG. 1, a secondary battery (1) according to one embodiment of the present invention can store electrical energy or output stored electrical energy according to design and needs. For example, the secondary battery (1) can accommodate an electrode assembly (12) in the form of a jelly-roll, which will be described later, within the battery.

[0052] In addition, the secondary battery (1) can prevent damage or ignition due to high temperature and high pressure by blocking the current flowing inside when the internal temperature or pressure increases abnormally due to an internal defect or external factor.

[0053] Additionally, the secondary battery (1) includes a configuration that performs a fire extinguishing function to extinguish flames and gases when high-temperature flames and gases are generated inside, thereby preventing the problem of flames and gases being transferred in advance.

[0054] Specifically, the secondary battery (1) may include a battery can (10), a top cap (11), an electrode assembly (12), an electrode lead (13), and a first extinguishing unit (140).

[0055] The battery can (10) has a can type and can form the outer surface of the secondary battery (1). Specifically, the battery can (10) can have a cylindrical type. However, the shape of the battery can (10) is not limited to a cylindrical shape and can be manufactured in various other shapes.

[0056] Additionally, the battery can (10) forms a receiving space on the inside, and the upper side of the battery can (10) can be opened. Conversely, the lower side of the battery can (10) can be formed in a sealed structure.

[0057] The battery can (10) may be made of a lightweight conductive metal material such as aluminum, nickel, stainless steel or an alloy thereof.

[0058] 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.

[0059] Figure 2 is a perspective view of an electrode assembly (12) according to Example 1 of the present invention.

[0060] Referring to FIG. 2, the electrode assembly (12) is positioned in the receiving space of the battery can (10) and can store or output electrical energy through a chemical reaction. For example, the electrode assembly (12) may have a jelly-roll shape. In other words, the electrode assembly (12) may have a shape in which a separator (122) is positioned between a positive electrode plate (120) and a negative electrode plate (121), and is wound and sequentially laminated.

[0061] The positive electrode plate (120) and the negative electrode plate (121) can be manufactured by applying an active material slurry to a metal current collector including aluminum or copper. As lithium ions move between the positive electrode plate (120) and the negative electrode plate (121), electrical energy can be stored or output from the electrode assembly (12).

[0062] The electrode lead (13) can electrically connect the electrode assembly (12) and at least one of the battery can (10) or the top cap (11). In other words, the electrode lead (13) can include a negative lead (131) electrically connecting the lower surface of the electrode assembly (12) and the inner lower surface of the battery can (10), and a positive lead (130) electrically connecting the upper surface of the electrode assembly (12) and the inner lower surface of the top cap (11).

[0063] However, the structure of the electrode lead (13) is not limited to this, and the electrode lead (13) may be formed in various shapes depending on the design, such as when both the positive lead (130) and the negative lead (131) are formed on the upper surface of the electrode assembly (12) or when the negative lead (131) is formed on the side of the electrode assembly (12).

[0064] The electrode lead (13) may be connected to a portion of the electrode assembly (12) where the active material slurry is not applied. For example, a non-coated portion where the active material slurry is not applied may be formed at the beginning and end of the positive and negative plates (120) and the negative plates (121) based on the direction in which the electrode plates are wound. The electrode lead (13) may be welded to the non-coated portion.

[0065] The first extinguishing unit (140) contains a extinguishing agent and can perform a extinguishing function. For example, when high-temperature flames and gases are generated in the electrode assembly (12) due to internal bonding or external factors, the first extinguishing unit (140) can release a specific extinguishing agent to extinguish the flames and gases.

[0066] The first digestive unit (140) may include a digestive substance composed of at least one component among NH4H2PO4, NAHCO3, KHCO3, CO2, CF2ClBr, CF3Br, H2SO4, K2CO3, or Al2(SO4)3.

[0067] Figure 3 is a perspective view of a first extinguishing unit (140) according to one embodiment of the present invention surrounding an electrode assembly (12).

[0068] Referring to FIG. 3, the first extinguishing member (140) may be formed to surround the outer surface of the electrode assembly (12). For example, the first extinguishing member (140) may be positioned between the electrode assembly (12) and the battery can (10) and may surround the side surface of the electrode assembly (12).

[0069] The first extinguishing member (140) may include a band shape that wraps around the outer surface of the electrode assembly (12). That is, the first extinguishing member (140) may be formed in a shape that wraps around the side surface of the electrode assembly (12) and, at the same time, tightens the side surface of the electrode assembly (12).

[0070] The first digestive unit (140) may include a band body and a digestive agent.

[0071] The band body can wrap around the outer surface of the electrode assembly (12). For example, the electrode assembly (12) has a jelly-roll shape, which is a cylindrical shape, and the band body can wrap around the side surface of the electrode assembly (12) along the perimeter of the electrode assembly (12).

[0072] Additionally, the band body forms a storage space inside, so that a digestive agent described later can be stored inside.

[0073] The band body may include a flexible and insulating material. For example, the band body may include at least one of a polypropylene (PP) material and a polyethylene (PE) material. That is, the band body may not electrically react to the electrolyte contained within the battery can (10).

[0074] The extinguishing agent is contained within the band body and may contain a extinguishing agent. For example, the extinguishing agent may be in powder form. Specifically, the extinguishing agent may be composed of at least one of NH4H2PO4, NAHCO3, or KHCO3.

[0075] However, the components of the digestive agent are not limited to this, and may be composed of various other components depending on the design and needs.

[0076] The thickness of the first extinguishing unit (140) may be 0.5 mm to 2 mm. If the thickness of the first extinguishing unit (140) is less than 0.5 mm, the first extinguishing unit (140) may become significantly thin, which may cause the first extinguishing unit (140) to be easily damaged or detached from the electrode assembly (12). In addition, if the thickness of the first extinguishing unit (140) is less than 0.5 mm, the first extinguishing unit (140) may not be able to sufficiently perform its extinguishing function.

[0077] On the other hand, if the thickness of the first extinguishing unit (140) exceeds 2 mm, a space is formed between the electrode assembly (12) and the battery can (10), which may lower the energy density of the secondary battery (1) and cause a problem in which the performance of the secondary battery (1) deteriorates. In addition, if the thickness of the first extinguishing unit (140) exceeds 2 mm, a space is formed between the electrode assembly (12) and the battery can (10), which may cause the electrode assembly (12) to be unstably fixed inside the battery can (10).

[0078] As a result, when 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) may also ignite, and the fire extinguishing agent contained inside the first fire extinguishing unit (140) may leak out. The leaked fire extinguishing agent may perform a fire extinguishing function by suppressing the flames and gases.

[0079]

[0080] Example 2

[0081]

[0082] Fig. 4 is a cross-sectional view of a secondary battery according to Example 2 of the present invention. Fig. 5 is a cross-sectional view showing an increase in internal pressure of a secondary battery according to Example 2 of the present invention. Fig. 6 is a cross-sectional view showing an appearance where the first current blocking part is broken due to an increase in internal pressure of a secondary battery according to Example 2 of the present invention. Fig. 7 is a cross-sectional view showing an appearance where the second current blocking part is detached from the battery can due to an increase in internal pressure of a secondary battery according to Example 2 of the present invention.

[0083] Hereinafter, a secondary battery according to Embodiment 2 of the present invention will be described. The secondary battery according to Embodiment 2 of the present invention may include a second extinguishing unit formed in a manner different from the first extinguishing unit described in the secondary battery according to Embodiment 1. Descriptions that overlap with those of the secondary battery according to Embodiment 1 described above will be omitted.

[0084] Referring to FIG. 4, the secondary battery according to Embodiment 2 of the present invention may include a fire extinguishing unit capable of extinguishing high-temperature flames generated internally. Accordingly, the secondary battery according to Embodiment 2 of the present invention may include a second fire extinguishing unit (141).

[0085] The second fire extinguishing unit (141) contains a fire extinguishing component and can perform a fire extinguishing function. For example, when 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 a specific fire extinguishing agent to extinguish the flames and gases.

[0086] The second digestion unit (141) may include a digestion material composed of at least one component among NH4H2PO4, NAHCO3, KHCO3, CO2, CF2ClBr, CF3Br, H2SO4, K2CO3, or Al2(SO4)3.

[0087] The second extinguishing unit (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 blocking unit (15) and a second current blocking unit (16) that block internal current according to an increase in internal temperature or pressure, and the second extinguishing unit (141) may be located in an area partitioned by the first current blocking unit (15) and the second current blocking unit (16).

[0088] More specifically, the first current cutoff unit (15) can be ruptured when the pressure inside the battery can (10) increases, thereby cutting off the current flowing inside. For example, the first current cutoff unit (15) can include a CID (Current Interrupt Device) filter.

[0089] In addition, the first current blocking unit (15) may be positioned on the upper side of the electrode assembly (12) and connected to the electrode lead (13). That is, the first current blocking unit (15) may be in contact with the electrode lead (13) while being spaced apart from the upper surface of the electrode assembly (12) by a certain distance. The first current blocking unit (15) may include a structure that is separated from the electrode lead (13) and broken when the pressure inside the battery can (10) increases.

[0090] The second current blocking unit (16) can block the current flowing inside the battery can (10) when the temperature inside the battery can (10) increases. For example, the second current blocking unit (16) can include a PTC (Positive Temperature Coefficient). That is, when the temperature inside the battery can (10) increases, the internal resistance of the second current blocking unit (16) increases, so that the internal current of the second current blocking unit (16) can be blocked.

[0091] The second current blocking unit (16) may be positioned between the first current blocking unit (15) and the top cap (11). For example, the second current blocking unit (16) may be connected to the top cap (11) to form a space between the second current blocking unit (16) and the top cap (11). In addition, a portion of the second current blocking unit (16) may be spaced apart from the first current blocking unit (15) to form a space between the second current blocking unit (16) and the first current blocking unit (15).

[0092] The second fire extinguishing unit (141) may include a lower fire extinguishing member (1410) positioned in the space between the first current breaker (15) and the second current breaker (16) and an upper fire extinguishing member (1411) positioned between the top cap (11) and the second current breaker (16).

[0093] The lower extinguishing member (1410) can be attached to the upper surface of the first current blocking member (15) facing the second current blocking member (16). For example, the lower extinguishing member (1410) can be attached to the upper surface of the first current blocking member (15) through a taping method.

[0094] Specifically, the lower extinguishing member (1410) may include a extinguishing body attached to the first current cutoff unit (15) and a liquid extinguishing agent that is contained within the extinguishing body in a liquid state and includes a extinguishing agent component. For example, the liquid extinguishing agent may include at least one component selected from the group consisting of NAHCO3, H2SO4, K2CO3, and Al2(SO4)3.

[0095] The upper extinguishing member (1411) may be attached to the upper surface of the second current blocking member (16) facing the top cap (11). Alternatively, the upper extinguishing member (1411) may be attached to the lower surface of the top cap (11) facing the second current blocking member (16).

[0096] In this way, when the upper extinguishing member (1411) is formed integrally with the top cap (11) or the second current blocking member (16), and the top cap (11) and the second current blocking member (16) are separated from the battery can (10) due to high temperature and high pressure inside, the upper extinguishing member (1411) can be separated from the battery can (10) together with the top cap (11) and the second current blocking member (16).

[0097] FIG. 5 is a cross-sectional view showing an appearance in which the internal pressure of a secondary battery (1) increases according to one embodiment of the present invention, and FIG. 6 is a cross-sectional view showing an appearance in which the first current blocking part (15) is broken due to an increase in the internal pressure of a secondary battery (1) according to one embodiment of the present invention.

[0098] Referring to FIGS. 5 and 6, when gas is generated from the electrode assembly (12) and the pressure inside the battery can (10) increases, the first current blocking portion (15) may be pushed upward by the pressure inside the battery can (10). When the pressure inside the battery can (10) increases further, a portion of the first current blocking portion (15) may be broken, and the current flowing inside the first current blocking portion (15) may be blocked.

[0099] In this case, the lower extinguishing member (1410) may be attached to a relatively low rigidity portion of the first current blocking member (15). That is, when the pressure inside the battery can (10) increases, a fracture phenomenon occurs in a relatively low rigidity portion of the first current blocking member (15), and the lower extinguishing member (1410) attached to that portion may also be fractured by receiving an external force.

[0100] In other words, when the fire extinguishing body is attached to a relatively low-rigidity portion of the first current breaker (15), the relatively low-rigidity portion of the first current breaker (15) may be broken and the fire extinguishing body may also be torn. At the same time, the liquid fire extinguishing agent contained inside the fire extinguishing body may leak out and flow into the broken portion, thereby allowing the liquid fire extinguishing agent to reach the electrode assembly (12).

[0101] 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 a state of high temperature and high pressure, a primary fracture occurs in a relatively low-rigidity portion of the first current blocking portion (15), so that as soon as flames and gases are generated, the lower extinguishing member (1410) can immediately extinguish the flames and gases.

[0102] In addition, since the lower extinguishing member (1410) includes a liquid extinguishing agent in a liquid state, the liquid extinguishing agent can penetrate the electrode assembly (12) and extinguish flames and gases more quickly.

[0103] FIG. 7 is a cross-sectional view showing a second current blocking unit (16) detached from a battery can (10) as the internal pressure of a secondary battery (1) increases according to one embodiment of the present invention.

[0104] Referring to Fig. 7, as the internal pressure of the battery can (10) increases, a break may occur in a part of the first current blocking portion (15), and the top cap (11) and the second current blocking portion (16) may be separated from the battery can (10) as one unit.

[0105] In this case, as described above, the upper extinguishing member (1411) can be detached from the battery can (10) together with the top cap (11) and the second current blocking member (16). In addition, the upper extinguishing member (1411) may include a solid form and may include a material that vaporizes when the temperature increases.

[0106] As a result, according to the structure and material characteristics of the upper extinguishing member (1411) as described above, when a battery module is formed by providing a plurality of secondary batteries (1), the upper extinguishing member (1411) can prevent the battery module from being damaged by fire.

[0107] Specifically, when a high-temperature flame and gas are generated in one of the plurality of secondary batteries (1), the upper extinguishing member (1411) is detached from the battery can (10) and vaporized, thereby spreading into the battery module in the form of gas, thereby preventing the phenomenon of the high-temperature flame and gas from spreading, thereby preventing secondary damage caused by the flame and gas in advance.

[0108]

[0109] Example 3

[0110]

[0111] Hereinafter, a secondary battery (1) according to Example 3 of the present invention will be described. Unlike the secondary battery (1) according to Example 1, the secondary battery (1) according to Example 3 of the present invention may include a different first extinguishing unit (140) structure. Descriptions that overlap with the contents of the secondary battery (1) according to Example 1 described above will be omitted.

[0112] Fig. 8 is a perspective view of a first extinguishing unit according to Example 3 of the present invention wrapping an electrode assembly. Fig. 9 is a perspective view of another view of a first extinguishing unit according to Example 3 of the present invention wrapping an electrode assembly.

[0113]

[0114] Referring to FIGS. 8 and 9, the first extinguishing unit (140) may include a plurality of components that surround the outer surface of the electrode assembly (12). For example, the first extinguishing unit (140) may include a plurality of components that are formed differently depending on the combination form of the electrode assembly (12) and the electrode lead (13). Specifically, the first extinguishing unit (140) may include an upper cover portion (1400) and a lower cover portion (1401).

[0115] The upper cover part (1400) can wrap around the upper side of the electrode assembly (12). The lower cover part (1401) can wrap around the lower side of the electrode assembly (12). That is, the lower cover part (1401) can be positioned lower than the upper cover part (1400) and formed to be spaced apart from the upper cover part (1400) by a certain distance.

[0116] Figure 8 is a perspective view of a first extinguishing unit (140) according to another embodiment of the present invention, which surrounds an electrode assembly (12).

[0117] Referring to FIG. 8, the positive lead (130) is connected to the upper surface of the electrode assembly (12) and can electrically connect the electrode assembly (12) and the top cap (11). The negative lead (131) can electrically connect the lower surface of the electrode assembly (12) and the battery can (10).

[0118] When the width of the upper cover part (1400) is L1 and the width of the lower cover part (1401) is L2, L1 and L2 may be the same. In other words, since the ignition phenomenon mainly occurs at the part where the positive electrode lead (130) and the negative electrode lead (131) are joined among each part of the electrode assembly (12), when 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 part (1400) and the width of the lower cover part (1401) to be the same.

[0119] In addition, when the width of the upper cover part (1400) is L1 and the distance between the upper cover part (1400) and the lower cover part (1401) is L3, L1 / L3 may be 0.5 to 3. That is, the upper cover part (1400) and the lower cover part (1401) may be spaced apart from each other by a certain interval.

[0120] Specifically, when L1 / L3 is less than 0.5, the upper cover part (1400) and the lower cover part (1401) are spaced apart by a considerable distance and the widths of the upper cover part (1400) and the lower cover part (1401) become thin, so that the extinguishing function of the first extinguishing part (140) may not be properly performed. On the other hand, when L1 / L3 exceeds 3, the distance between the upper cover part (1400) and the lower cover part (1401) becomes short, so that most of the side surface of the electrode assembly (12) is covered by the upper cover part (1400) and the lower cover part (1401), so that the energy density of the secondary battery (1) is lowered, so that the performance of the secondary battery (1) may deteriorate.

[0121] Figure 9 is a perspective view of a first extinguishing unit (140) according to another embodiment of the present invention surrounding an electrode assembly (12).

[0122] Referring to FIG. 9, the positive lead (130) can electrically connect the upper surface of the electrode assembly (12) and the top cap (11), and the negative lead (131) can electrically connect the upper surface of the electrode assembly (12) and the battery can (10). That is, the positive lead (130) and the negative lead (131) can be connected to the same upper surface of the electrode assembly (12).

[0123] As previously explained, among the parts of the electrode assembly (12), since the ignition phenomenon mainly occurs at the part where the positive lead (130) and the negative lead (131) are connected, when the positive lead (130) and the negative lead (131) are formed by being connected to the upper surface, i.e., the upper side, of the electrode assembly (12), the width of the upper cover part (1400) may be considerably larger than the width of the lower cover part (1401).

[0124] Specifically, when the width of the upper cover part (1400) is L1 and the width of the lower cover part (1401) is L2, L1 / L2 may be 3 to 10. When L1 / L2 is less than 3, the width of the upper cover part (1400) becomes thin, and thus the fire extinguishing function for the upper side of the electrode assembly (12) where the positive lead (130) and the negative lead (131) are distributed may be reduced. On the other hand, when L1 / L2 exceeds 10, the width of the upper cover part (1400) becomes excessively wide, and thus the fire extinguishing function is concentrated only on the upper side of the electrode assembly (12), and thus the fire extinguishing function for the lower side of the electrode assembly (12) may be reduced.

[0125] Lastly, when the positive electrode lead (130) is connected to the upper surface of the electrode assembly (12) and electrically connects the electrode assembly (12) and the top cap (11), and the negative electrode lead (131) electrically connects the lower surface and side surface 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).

[0126] Specifically, when the width of the upper cover part (1400) is L1 and the width of the lower cover part (1401) is L2, L1 / L2 may be 3 to 6. This is because the negative lead (131) is formed with a large contact area, and therefore the temperature of the positive lead (130) becomes higher, causing ignition to occur more frequently. Therefore, it may be desirable to design the width of the upper cover part (1400) to be wider than the width of the lower cover part (1401).

[0127] As a result, by designing the upper cover part (1400) and the lower cover part (1401) differently depending on the shape of the electrode assembly (12) and the electrode lead (13), when high-temperature flames and gases are generated from the electrode assembly (12), the first fire extinguishing part (140) can perform the fire extinguishing function more effectively.

[0128]

[0129] Example 4

[0130]

[0131] Hereinafter, a secondary battery (1) according to Embodiment 4 of the present invention will be described. Unlike the secondary batteries (1) according to Embodiments 1 to 3, the secondary battery (1) according to Embodiment 4 of the present invention may include a different digestive structure. Descriptions of contents overlapping with those of the secondary batteries (1) according to Embodiments 1 to 3 described above will be omitted.

[0132] The secondary battery according to Example 4 of the present invention may further include a third digestion unit (142) designed in the separator (122).

[0133] Figure 10 is a cross-sectional view of a third digestion unit (142) and a separation membrane (122) according to Example 4 of the present invention.

[0134] Referring to FIG. 10, the separator (122) is composed of multiple layers, and the third extinguishing unit (142) can be laminated between the multiple layers of the separator (122). That is, the third extinguishing unit (142) can be applied to 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 with the third extinguishing unit (142) accommodated therein to become a part of the electrode assembly (12).

[0135] As a result, according to the structure of the third fire extinguishing unit (142) as described above, since the third fire extinguishing unit (142) is manufactured integrally with the separator (122) in a sealed state inside the separator (122), when a high-temperature flame and gas are generated in a part of the electrode assembly (12), the third fire extinguishing unit (142) accommodated in the separator (122) can immediately perform the fire extinguishing function. In addition, since the third fire extinguishing unit (142) is manufactured integrally with the separator (122), there may be an advantage in that a separator (122) having a fire extinguishing function can be designed more easily.

[0136] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0137] Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention but to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments.

[0138] The scope of protection of the present invention should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

[0139] [Explanation of symbols]

[0140] 1: Secondary battery

[0141] 10: Battery can

[0142] 11: Top cap

[0143] 12: Electrode assembly

[0144] 13: Electrode leads

[0145] 15: First current breaker

[0146] 16: Second current breaker

[0147] 120: Bipolar plate

[0148] 121: Negative plate

[0149] 122: Membrane

[0150] 130: Positive lead

[0151] 131: Negative lead

[0152] 140: First Fire Department

[0153] 141: 2nd Fire Department

[0154] 142: Third Fire Department

[0155] 1400: Upper cover

[0156] 1401: Lower cover

[0157] 1410: Lower digestive tract

[0158] 1411: Upper digestive tract member

Claims

1. A battery can having an open top and forming a receiving space inside; A top cap covering the open upper side of the battery can; An electrode assembly comprising a sequentially laminated form wound with a separator positioned between a positive electrode plate and a negative electrode plate, and positioned in the receiving space; An electrode lead electrically connecting the electrode assembly and at least one of the battery can or the top cap; and A secondary battery comprising a first extinguishing unit comprising a extinguishing component and positioned between the electrode assembly and the battery can.

2. In paragraph 1 A secondary battery, wherein the first digestive unit includes a band shape that wraps around the outer surface of the electrode assembly.

3. In paragraph 2 The first fire department, An upper cover portion covering the upper side of the electrode assembly; and A secondary battery comprising a lower cover portion that surrounds the lower side of the electrode assembly.

4. In paragraph 3 The electrode lead includes a positive lead electrically connected to the positive plate and a negative lead electrically connected to the negative plate, The positive lead is connected to the upper surface of the electrode assembly and electrically connects the electrode assembly and the top cap, and the negative lead electrically connects the lower surface of the electrode assembly and the battery can. A secondary battery, wherein when the width of the upper cover part is L1 and the distance between the upper cover part and the lower cover part is L3, L1 / L3 is 0.5 to 3.

5. In paragraph 4 When the width of the lower cover part is L2, L1 and L2 are the same, secondary battery.

6. In paragraph 3 The electrode lead includes a positive lead electrically connected to the positive plate and a negative lead electrically connected to the negative plate, The positive lead electrically connects the upper surface of the electrode assembly and the top cap, and the negative lead electrically connects the upper surface of the electrode assembly and the battery can. A secondary battery, wherein when the width of the upper cover part is L1 and the width of the lower cover part is L2, L1 / L2 is 3 to 10.

7. In paragraph 3 The electrode lead includes a positive lead electrically connected to the positive plate and a negative lead electrically connected to the negative plate, The positive lead is connected to the upper surface of the electrode assembly and electrically connects the electrode assembly and the top cap, and the negative lead electrically connects the lower surface and the side surface of the electrode assembly to the battery can. A secondary battery, wherein when the width of the upper cover part is L1 and the width of the lower cover part is L2, L1 / L2 is 3 to 6.

8. In paragraph 2 The above first digestive unit A band body that wraps around the outer surface of the electrode assembly; and A secondary battery, which is accommodated inside the band body and includes a fire extinguishing agent containing the fire extinguishing component.

9. In paragraph 8 The above band body is a secondary battery comprising at least one material selected from the group consisting of PP (Poly Propylene) material and PE (Polyethylene) material.

10. In paragraph 2 A secondary battery, wherein the thickness of the first digestive section is 0.5 mm to 2 mm.

11. A battery can having an open top and forming a receiving space on the inside; A top cap covering the open upper side of the battery can; An electrode assembly comprising a sequentially laminated form wound with a separator positioned between a positive electrode plate and a negative electrode plate, and positioned in the receiving space; An electrode lead electrically connecting the electrode assembly and at least one of the battery can or the top cap; and A secondary battery comprising a digestive component and a second digestive unit positioned between the upper side of the electrode assembly and the top cap.

12. In Article 11 A first current blocking unit located on the upper side of the electrode assembly and connected to the electrode lead, which breaks when the pressure inside the battery can increases and blocks the current flowing inside; and It further includes a second current breaker located between the first current breaker and the top cap, which blocks the current flowing inside when the temperature increases. The above second digestive unit, A lower extinguishing member located in the space between the first current blocking unit and the second current blocking unit; and A secondary battery comprising an upper extinguishing member positioned between the top cap and the second current blocking member.

13. In paragraph 12 A secondary battery, wherein the lower digestion member is attached to the upper surface of the first current blocking unit facing the second current blocking unit.

14. In Article 13 A secondary battery wherein the lower digestion member is attached to a relatively low rigidity portion among the portions of the first current blocking section.

15. In Article 14 The above lower digestive member is, A fire extinguishing body attached to the first current breaker; and A secondary battery comprising a liquid extinguishing agent contained within the digestive body in a liquid state and containing a digestive component.

16. In Article 13 A secondary battery in which the lower digestive member is attached to the upper surface of the first current blocking section by taping.

17. In paragraph 12 A secondary battery, wherein the upper digestive member comprises a solid form and includes a material that vaporizes when the temperature increases.

18. In paragraph 1 or paragraph 11 The above separation membrane is composed of multiple layers, A secondary battery, wherein the digestion unit further includes a third digestion unit laminated between the plurality of layers of the separator.

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