Secondary battery cell, and secondary battery pack and vehicle comprising same

Abstract

A secondary battery cell according to the present invention comprises: a housing in which an electrode assembly and an electrolyte are accommodated; a top cap which covers an opening formed on one side of the housing; and a safety vent which is located below the top cap and includes a rupture portion that ruptures due to a pressure increase inside the housing to exhaust gas, wherein a gas-generating material is included inside the housing, and when the secondary battery cell is exposed to a temperature higher than or equal to a predetermined temperature, the gas-generating material reacts with components of the secondary battery cell to generate gas, thereby inducing early venting of the safety vent.

Description

Secondary battery cell, secondary battery pack including the same, and automobile

[0001] The present invention relates to a secondary battery cell, a secondary battery pack including the same, and an automobile. Specifically, the invention relates to a secondary battery cell capable of inducing early venting by arbitrarily generating gas when the secondary battery cell is exposed to abnormal conditions above a predetermined temperature, a secondary battery pack including the same, and an automobile.

[0002]

[0003] Secondary batteries, which offer high applicability across product categories and possess electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric power sources.

[0004] These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, as they not only have the primary advantage of being able to drastically reduce the use of fossil fuels but also the advantage of not generating any by-products from the use of energy.

[0005] Currently, widely used types of rechargeable batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries.

[0006] The operating voltage of such a unit secondary battery cell is approximately 2.5V to 4.5V.

[0007] Therefore, if a higher output voltage is required, a secondary battery pack is formed by connecting multiple secondary battery cells in series.

[0008] In addition, a secondary battery pack is sometimes configured by connecting multiple secondary battery cells in parallel, depending on the charge and discharge capacity required for the secondary battery pack.

[0009] Accordingly, the number of secondary battery cells included in the above secondary battery pack can be set to vary depending on the required output voltage and / or charge / discharge capacity.

[0010]

[0011] FIG. 1 is a vertical cross-sectional view of a cylindrical secondary battery cell according to the prior art.

[0012] A cylindrical secondary battery cell (100) has an electrode assembly (110) housed inside a housing (120).

[0013] A cap assembly (130) is positioned on the upper part of the cylindrical secondary battery cell (100), and the cylindrical secondary battery cell (100) is sealed by a clamping gasket (133).

[0014] The cap assembly (130) includes a safety vent (132) located at the bottom of the top cap and surrounding the outer circumference of the top cap (131), and a current blocking member (135) located at the bottom of the safety vent (123) while in contact with the center of the safety vent (132).

[0015] A current blocking gasket (134) is located on the outer periphery of the current blocking member (135) to prevent the safety vent (132) from coming into contact with the current blocking member (135) in a part other than the center of the current blocking member (135).

[0016] The positive tab (111) of the electrode assembly (110) is attached to the lower surface of the current blocking member (135), so that the top cap (131) acts as a positive terminal.

[0017] The unexplained symbol 122 is the clamping part, and 124 is the beading part.

[0018] Meanwhile, unlike primary batteries that cannot be reused after a single discharge, lithium secondary batteries are reusable batteries.

[0019] At this time, as charging and discharging continue, gas is inevitably generated due to electrochemical side reactions occurring inside the secondary battery cell, and this gas increases the pressure inside the secondary battery cell.

[0020] This interferes with the electrochemical reaction inside the secondary battery cell, increasing internal resistance and reducing charge and discharge capacity.

[0021]

[0022] Figure 2 is a graph showing the ignition mechanism after high-temperature exposure of a cylindrical secondary battery cell according to the prior art.

[0023] When a cylindrical secondary battery cell is exposed to a temperature above a certain level, gas is generated due to the decomposition reaction of the SEI (Solid Electrolyte Interphase) film on the electrode surface.

[0024] For example, when a cylindrical secondary battery cell is exposed to a high temperature of approximately 100°C or higher, gas is generated due to the decomposition reaction of the SEI (Solid Electrolyte Interphase) film on the electrode surface, and as the temperature rises further, additional gas generation side reactions occur, causing venting in the safety vent of the cap assembly.

[0025] As it is vented from the safety vent, heat inside the cylindrical secondary battery cell is released to the outside, reducing the temperature rise of the cylindrical secondary battery cell and lowering the temperature.

[0026] Under these circumstances, the longer the venting of the safety vent is delayed, the greater the amount of gas trapped inside the cylindrical secondary battery cell becomes, and the temperature inside the cylindrical secondary battery cell continues to rise, increasing the risk of ignition of the cylindrical secondary battery cell.

[0027] Generally, measures to lower the vent pressure of a cap assembly involve reducing the thickness of the notched portion of the safety vent or changing the material; however, this is not an effective solution because lowering the vent pressure of the cap assembly and the secondary battery itself can lead to premature venting caused by gases generated during long-term use.

[0028] When a cylindrical secondary battery cell is exposed to high temperatures, if the safety vent of the cap assembly activates late, high-temperature gas inside the cylindrical secondary battery cell is trapped, inducing self-heating within the component. There is a problem in that the temperature continues to rise even after the safety vent activates, potentially causing the cylindrical secondary battery cell to explode.

[0029]

[0030] The present invention has been devised to solve various conventional problems as described above, and aims to provide a secondary battery cell capable of reducing the risk of ignition of a secondary battery cell by preventing the internal temperature of the secondary battery cell from continuously rising by arbitrarily generating gas to induce early venting when the secondary battery cell is exposed to abnormal conditions above a predetermined temperature, as well as a secondary battery pack including the same and an automobile.

[0031]

[0032] To achieve the above objectives, a secondary battery cell according to the first aspect of the present invention comprises: a housing in which an electrode assembly and an electrolyte are contained; a top cap covering an opening formed on one side of the housing; and a safety vent located at the bottom of the top cap and including a rupture portion that ruptures due to a pressure increase inside the housing to exhaust gas; wherein the housing contains a gas-generating material, and when the secondary battery cell is exposed to a temperature above a predetermined temperature, the gas-generating material reacts with a component of the secondary battery cell to generate gas, thereby inducing early venting of the safety vent.

[0033] The above gas generating material is in the form of a solution and can be applied to the inner surface of the housing and then dried.

[0034] In addition, the gas generating material may be in the form of a solution and then dried after being applied to the inner surface of the top cap.

[0035] In addition, the gas generating material may be in the form of a solution and then dried after being applied to the inner surface of the safety vent.

[0036] In addition, the gas generating material may be included in the electrolyte to decompose at a specific temperature to generate gas.

[0037] The above safety vent can form a circular closed loop.

[0038] The above safety vent may be formed with a thickness thinner than the surrounding area of ​​the housing cover so that it can easily break when the internal pressure of the housing increases to a certain level.

[0039] The above secondary battery cell is preferably a cylindrical secondary battery cell or a prismatic secondary battery cell.

[0040] The above electrode assembly may be of the jelly-roll type.

[0041] Meanwhile, a secondary battery pack according to the second aspect of the present invention may include the aforementioned secondary battery cell and a pack housing in which a plurality of the secondary battery cells are provided and stored.

[0042] An automobile according to a third aspect of the present invention may include the aforementioned secondary battery cell or the aforementioned secondary battery pack.

[0043]

[0044] According to the means for solving the aforementioned problem, the present invention has the following effects.

[0045] The present invention includes a gas-generating material inside the housing of a secondary battery cell, and when the secondary battery cell is exposed to a temperature above a predetermined temperature, the gas-generating material reacts with the components of the secondary battery cell to generate gas, thereby inducing early venting of the safety vent, which prevents the internal temperature of the secondary battery cell from continuously rising and has the effect of reducing the risk of ignition of the secondary battery cell.

[0046]

[0047] FIG. 1 is a vertical cross-sectional view of a cylindrical secondary battery cell according to the prior art.

[0048] Figure 2 is a graph showing the ignition mechanism after high-temperature exposure of a cylindrical secondary battery cell according to the prior art.

[0049] FIG. 3 is a vertical cross-sectional view schematically showing the interior of a cylindrical secondary battery cell according to one embodiment of the present invention.

[0050] FIG. 4 is a diagram showing a state in which a gas generating material is applied to the inner surface of a housing in a cylindrical secondary battery cell according to one embodiment of the present invention.

[0051] FIG. 5 is a diagram showing a state in which a gas generating material is applied to the top cap and safety vent of a cylindrical secondary battery cell according to one embodiment of the present invention.

[0052] FIG. 6 is a graph showing the temperature change when a conventional cylindrical secondary battery cell and a cylindrical secondary battery cell according to the present invention are exposed to high temperatures.

[0053] FIG. 7 is a schematic diagram showing the configuration of a secondary battery pack according to the present invention.

[0054] FIG. 8 is a schematic diagram showing a vehicle including the secondary battery pack of FIG. 7.

[0055]

[0056] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Accordingly, in some embodiments, well-known process steps, well-known device structures, and well-known techniques are not specifically described to avoid the present invention being interpreted ambiguously. Throughout the specification, like reference numerals refer to like components.

[0057] In drawings, thicknesses may be enlarged to clearly represent multiple layers and regions. Throughout the specification, the same reference numerals are used for similar parts. When a part such as a layer, film, region, or plate is described as being "above" another part, this includes not only cases where it is "immediately above" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately above" another part, it means that there is no other part in between. Furthermore, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only cases where it is "immediately below" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately below" another part, it means that there is no other part in between.

[0058] FIG. 3 is a vertical cross-sectional view schematically showing the interior of a cylindrical secondary battery cell according to one embodiment of the present invention.

[0059] A cylindrical secondary battery cell (1) according to one embodiment of the present invention includes an electrode assembly (10), a housing (20), and a cap assembly (30).

[0060] The cylindrical secondary battery cell (1) may further include a sealing gasket (40) and / or a current collector (50) and / or an insulating plate (60).

[0061] The electrode assembly (10) includes a first electrode (11) having a first polarity, a second electrode (not shown) having a second polarity, and a separator (not shown) interposed between the first electrode (11) and the second electrode.

[0062] For example, the first electrode (11) may be a positive or negative electrode, and the second electrode may correspond to an electrode having a polarity opposite to that of the first electrode (11).

[0063] The electrode assembly (10) may have a structure in which a first electrode (11) and a second electrode and a separator interposed between them are wound in one direction.

[0064] The electrode assembly (10) may have, for example, a jelly-roll structure.

[0065] That is, the electrode assembly (10) can be manufactured by winding a laminate formed by stacking a first electrode current collector and a second electrode current collector having a sheet shape at least once with a separator interposed between them in one direction with respect to the center of the winding.

[0066] Any jelly roll structure known in the industry may be applied to the present invention without limitation.

[0067] The housing (20) may be configured to include an opening on one side and to accommodate an electrode assembly (10) through the opening.

[0068] Specifically, the housing (20) is a roughly cylindrical receptacle with an opening formed on one side, and is made of a conductive material such as metal, for example.

[0069] The material of the housing (20) may be, for example, steel, stainless steel, or nickel-plated steel.

[0070] An opening may be formed on the upper side of the housing (20).

[0071] That is, the opening can be provided at the top of the cylindrical secondary battery cell (1).

[0072] The lower surface located opposite the above-mentioned opening is to be referred to as the closing portion.

[0073] The side wall and the closure of the housing (20) can be formed integrally.

[0074] In contrast, the side wall and the closing portion of the housing (20) may be provided separately from each other and joined together by welding or the like.

[0075] The lower surface of the housing (20), that is, the outer surface of the closed portion, can have a roughly flat shape.

[0076] The housing (20) accommodates the electrode assembly (10) through an opening formed at the top, and also accommodates the electrolyte.

[0077] The housing (20) can be electrically connected to the electrode assembly (10).

[0078] The housing (20) can be electrically connected, for example, to the second non-electrical portion of the electrode assembly (10).

[0079] In this case, the housing (20) may have the same polarity as the second non-porous part.

[0080] The housing (20) may have a beading portion (21) and / or a clamping portion (22) formed on its upper side.

[0081] The beading portion (21) is formed adjacent to the upper opening of the housing (20).

[0082] The beading portion (21) has a shape that is drawn inward along the outer circumference of the housing (20).

[0083] That is, the beading portion (21) has a shape that is inserted to a predetermined depth along the radial direction from the outer surface of the housing (20) and extends along the circumferential direction of the housing (20).

[0084] The beading portion (21) prevents the electrode assembly (10), which has a size corresponding to the width of the housing (20), from coming out through the upper opening of the housing (20), and can function as a support portion on which the top cap (31) is seated.

[0085] The clamping portion (22) can be formed in the upper region of the housing (20).

[0086] The clamping portion (22) may have a shape that extends inward along the radial direction of the cylindrical secondary battery cell (1) from the upper circumference of the housing (20).

[0087] The clamping portion (22) is provided in an area corresponding to the edge perimeter of the upper surface of the top cap (31) to fix the top cap (31) described later, thereby preventing the top cap (31) from moving upward.

[0088] When a beading portion (21) is provided in the housing (20), a clamping portion (22) is formed on the upper part of the beading portion (21).

[0089] The clamping portion (22) extends from the beading portion (21) and has a shape that is extended and bent to wrap around the outer surface of the top cap (31) placed on the beading portion (21) and a part of the upper surface of the top cap (31).

[0090] The upper portion of the clamping portion (22) may have a shape that extends inward by a predetermined distance along the radial direction of the cylindrical secondary battery cell (1) and wraps around a part of the upper surface of the top cap (31).

[0091] Thus, the clamping part (22) secures the edge of the upper surface of the top cap (31).

[0092] That is, the perimeter area of ​​the top cap (31) is interposed between the top of the clamping portion (22) and the beading portion (21) and is fixed to the housing (20), covering the opening of the housing (20).

[0093] The cap assembly (30) includes a top cap (31) and a safety vent (32).

[0094] In addition to this, the cap assembly (30) may further include a connecting member (33).

[0095] The cap assembly (30) can be coupled to one end of the housing (20).

[0096] The top cap (31) can be attached to the opening of the housing (20).

[0097] Preferably, the top cap (31) can be sealedly coupled to the opening of the housing (20).

[0098] The top cap (31) may be made of a conductive metal material.

[0099] The top cap (31) can be configured to cover the top opening of the housing (20).

[0100] The top cap (31) can be electrically connected to the first electrode (11) of the electrode assembly (10).

[0101] Additionally, the top cap (31) can be electrically insulated from the housing (20).

[0102] Accordingly, the top cap (31) has the same first polarity as the first electrode (11) of the electrode assembly (10) and can function as the first electrode (11) terminal of the cylindrical secondary battery cell (1) of the present invention.

[0103] The electrical connection between the first electrode (11) and the top cap (31) can be made, for example, by a current collector (50) and / or a lead (51).

[0104] The top cap (31) can be seated on the beading portion (21) formed in the housing (20).

[0105] The top cap (31) can be secured by the clamping part (22).

[0106] That is, the top cap (31) can be supported by the upper surface of the beading part (21) at the perimeter of the lower edge, and the perimeter of the upper surface can be fixed by the bending of the upper part of the clamping part (22).

[0107] The top cap (31) can be formed with its central portion protruding upward.

[0108] More specifically, the approximately central part of the top cap (31) can be configured to protrude upward.

[0109] The top cap (31) may be provided at a position corresponding to the winding center hole formed in the approximately center of the cylindrical secondary battery cell (1).

[0110] The top cap (31) can protrude upward higher than the upper surface of the housing (20) to facilitate contact with electrical connection components such as a bus bar.

[0111] The top cap (31) may include a flat portion (311), an end portion (312), and an inclined portion (313).

[0112] The flat portion (311) may be provided in the central area of ​​the top cap (31).

[0113] The flat portion (311) is configured to have a roughly flat shape, and the center may be configured to rise upward.

[0114] The flat portion (311) rising upward can function as an electrode terminal.

[0115] For example, the flat portion (311) can function as a positive terminal.

[0116] The end portion (312) can be seated on the beading portion (21) formed in the housing (20).

[0117] The end portion (312) can be fixed by the clamping portion (22).

[0118] That is, the end portion (312) can have its lower edge perimeter supported by the upper surface of the beading portion (21), and its upper edge perimeter can be fixed by the bending of the upper portion of the clamping portion (22).

[0119] The inclined portion (313) refers to the area connecting the flat portion (311) and the end portion (312).

[0120] If the flat portion (311) is a structure that rises upward, the inclined portion (313) may be composed of an inclined area where the height decreases from the center to the end.

[0121] The safety vent (32) can be located at the bottom of the top cap (31).

[0122] The safety vent (32) may include a rupture portion (32a) that ruptures due to a rise in pressure inside the battery housing (20) to exhaust gas.

[0123] That is, the fracture portion (32a) can be configured to rupture when the internal pressure of the housing (20) increases.

[0124] For example, if gas is generated in the electrode assembly (10) due to overcharging of the cylindrical secondary battery cell (1), the internal pressure of the housing (20) increases.

[0125] At this time, the safety vent (32) is deformed upward and separated from the connecting member (33), so that the current is automatically cut off, thereby ensuring the safety of the battery.

[0126] That is, the safety vent (32) can be configured to be deformable upward when the internal pressure of the housing (20) increases.

[0127] In addition, if the internal pressure continues to increase, the safety vent (32) ruptures and the gas is exhausted, thereby preventing the explosion of the cylindrical secondary battery cell (1).

[0128] The safety vent (32) may include a center (321), a connecting part (322), and an outer part (323).

[0129] The center (321) may be provided in the approximately central area of ​​the safety vent (32).

[0130] The center (321) can be configured in the shape of a roughly circular plate.

[0131] The connecting portion (322) may be an area extending radially outward from the center (321).

[0132] The connecting part (322) can be configured to have a structure that slopes upward as it moves outward in the radial direction in a normal state.

[0133] That is, the connecting part (322) can be configured to form a predetermined angle with the center (321).

[0134] The outer portion (323) may be an area extending radially outward from the connecting portion (322).

[0135] The outer portion (323) can again be configured to be approximately parallel to the center (321).

[0136] That is, the outer portion (323) can be configured to form a predetermined angle with the connecting portion (322).

[0137] Here, the fracture portion (32a) may be provided between the center (321) and the connecting portion (322).

[0138] For example, the fracture portion (32a) may correspond to an area provided in a notch shape between the center (321) and the connecting portion (322).

[0139] For example, the fractured portion (32a) may be configured to be thinner or have lower density than the surrounding area, thereby meaning an area that is easier to fracture than the surrounding area.

[0140] Meanwhile, the fracture portion (32a) may be additionally provided between the connecting portion (322) and the outer portion (323).

[0141] The shape of the notch is preferably a V-shaped groove structure as shown in FIG. 3, but the shape and number can be varied as needed.

[0142] Preferably, the break portion (32a) can be provided along a closed loop.

[0143] More preferably, the break portion (32a) may be provided in a continuous form along a closed loop.

[0144] That is, the fracture portion (32a) can be formed into a circle having a predetermined radius.

[0145] Meanwhile, the upper end of the connecting member (33) can be in contact with the safety vent (32).

[0146] The lower end of the connecting member (33) can be connected to the electrode assembly (10) or the lead (51).

[0147] The safety vent (32) may include a banding portion that wraps around the edge of the top cap (31).

[0148] The banding portion can be formed by the banding of the notch portion provided in the safety vent (32) and configured to be in close contact with the edge of the top cap (31).

[0149] The safety vent (32) can be bent at a right angle so as to be perpendicular to the outer surface of the top cap (31) and can be tightly coupled with the top cap (31).

[0150] Accordingly, a banding portion is formed that wraps around the edge of the top cap (31), and the end of the safety vent (32) is positioned on the top of the top cap (31).

[0151] The cylindrical secondary battery cell (1) of the present invention configured as described above includes a gas generating material (M) inside the housing (20) as shown in FIGS. 4 and FIGS. 5, which will be described later. When the cylindrical secondary battery cell (1) is exposed to a temperature above a predetermined temperature, the gas generating material (M) reacts with the components of the cylindrical secondary battery cell (1) (electrolyte, electrode, and other components, etc.) to generate gas, thereby inducing early venting of the safety vent (32), which prevents the internal temperature of the cylindrical secondary battery cell (1) from continuously rising, thereby reducing the risk of ignition of the cylindrical secondary battery cell (1).

[0152] For example, a secondary battery cell (1) according to one embodiment of the present invention is designed so that when exposed to a high temperature of approximately 100°C or higher, a gas generating material (M) reacts with a component of the cylindrical secondary battery cell (1) to generate gas, thereby inducing early venting of the safety vent (32), which prevents the internal temperature of the cylindrical secondary battery cell (1) from rising continuously, thereby reducing the risk of ignition of the cylindrical secondary battery cell (1).

[0153] A detailed explanation of this will be provided later.

[0154]

[0155] FIG. 4 is a diagram showing a state in which a gas generating material is applied to the inner surface of a housing in a secondary battery cell according to one embodiment of the present invention.

[0156] The gas generating material (M) is in the form of a solution and can be applied to the inner surface of the housing (20) (for example, the inner surface of the housing (20) in the case of a cylindrical secondary battery cell (1)) and then dried.

[0157] For example, when a cylindrical secondary battery cell (1) is exposed to a high temperature of approximately 100°C or higher, a gas generating material (M) that is applied to the inner surface of the housing (20) and then dried reacts with the electrolyte, electrode, and other parts of the cylindrical secondary battery cell (1) to generate gas, thereby inducing early venting of the safety vent (32).

[0158] Such gas generating material is not particularly limited as long as it is a material that initiates a reaction and releases gas when the temperature of the cylindrical secondary battery cell (1) rises, and may be, for example, lithium carbonate (Li2CO3), CaCO3, K2CO3, Na2CO3 or BaCO3.

[0159] Accordingly, the internal temperature of the cylindrical secondary battery cell (1) is prevented from rising continuously, thereby reducing the risk of ignition of the cylindrical secondary battery cell (1).

[0160]

[0161] FIG. 5 is a diagram showing a state in which a gas generating material is applied to the top cap and safety vent in a secondary battery cell according to one embodiment of the present invention.

[0162] The gas generating material (M) is in the form of a solution and can be applied to the inner surface of the top cap (31) of the secondary battery cell (1) and the inner surface of the safety vent (32) (the surface facing the electrode assembly (10)) and then dried.

[0163] For example, when a cylindrical secondary battery cell (1) is exposed to a high temperature of approximately 100°C or higher, a gas generating material (M) that is applied to the inner surface of the top cap (31) of the cap assembly (30) and the inner surface of the safety vent (32) and then dried reacts with the electrolyte, electrode, and other parts of the cylindrical secondary battery cell (1) to generate gas and induce early venting of the safety vent (32).

[0164] Accordingly, the internal temperature of the cylindrical secondary battery cell (1) is prevented from rising continuously, thereby reducing the risk of ignition of the cylindrical secondary battery cell (1).

[0165] Meanwhile, the gas generating material (M) may be in the form of a solution and may be applied to the inner surface of the housing (20) of the cylindrical secondary battery cell (1), the inner surface of the top cap (31), and the inner surface of the safety vent (32), and then dried.

[0166] In addition, the gas generating substance (M) may be included in the electrolyte to decompose at a specific temperature to generate gas.

[0167] Such gas generating material is not particularly limited as long as it is a material that initiates a reaction and releases gas when the temperature of the cylindrical secondary battery cell (1) rises, and may be, for example, lithium carbonate (Li2CO3), CaCO3, K2CO3, Na2CO3 or BaCO3.

[0168]

[0169] FIG. 6 is a graph showing the temperature change when a conventional cylindrical secondary battery cell and a cylindrical secondary battery cell according to the present invention are exposed to high temperatures.

[0170] When a cylindrical secondary battery cell is exposed to a high temperature of about 130°C, an equivalent level of temperature increase occurs up to about 130°C. However, in the case of the present invention (improved product), a large amount of gas is generated by a gas-generating material at high temperature, so the safety vent activates first and the temperature of the cylindrical secondary battery cell decreases, whereas in the case of the conventional product (existing product), the high-temperature gas inside is further captured for about 2.5 minutes, causing self-heating of the cylindrical secondary battery cell, and as a result, an explosion of the cylindrical secondary battery cell may occur after the safety vent activates.

[0171]

[0172] FIG. 7 is a schematic diagram showing the configuration of a secondary battery pack according to the present invention.

[0173] The cylindrical secondary battery pack (3) according to the present invention may include the aforementioned cylindrical secondary battery cell (1) and a pack housing (3a) in which a plurality of cylindrical secondary battery cells (1) are provided and stored.

[0174] The cylindrical secondary battery pack (3) further includes a pack housing (3a) for housing a cylindrical secondary battery cell (1), and various devices for controlling the charging and discharging of the cylindrical secondary battery cell (1), such as a BMS, a current sensor, a fuse, etc.

[0175]

[0176] FIG. 8 is a schematic diagram showing a vehicle including the secondary battery pack of FIG. 7.

[0177] The automobile (5) according to the present invention may include the aforementioned cylindrical secondary battery cell (1) and the aforementioned cylindrical secondary battery pack (3).

[0178] A cylindrical secondary battery cell (1) or a cylindrical secondary battery pack (3) can be applied to a vehicle (5), for example, an electric vehicle or a hybrid vehicle, which is configured to use electricity.

[0179] Although the secondary battery cell and secondary battery pack described in this specification are cylindrical only, the early venting structure of the secondary battery cell according to the present invention is naturally applicable to prismatic secondary battery cells and prismatic secondary battery packs as well.

[0180]

[0181] [Explanation of the symbol]

[0182] M: Gas-generating substance

[0183] 1 : Secondary battery cell

[0184] 10: Electrode assembly

[0185] 20 : Housing

[0186] 30: Cap assembly

[0187] 31 : Top Cap

[0188] 32: Safety vent

[0189] 3 : Secondary battery pack

[0190] 5 : Cars

Claims

1. A secondary battery cell comprising: a housing that accommodates an electrode assembly and an electrolyte inside; a top cap that covers an opening formed on one side of the housing; and a safety vent located at the bottom of the top cap and including a rupture portion that ruptures due to a rise in pressure inside the housing to exhaust gas. The interior of the above housing contains a gas-generating material, and When the secondary battery cell is exposed to a temperature above a predetermined temperature, the gas generating substance reacts with the components of the secondary battery cell to generate gas, thereby inducing early venting of the safety vent. Secondary battery cell.

2. In Claim 1, The above gas generating material is in the form of a solution and is applied to the inner surface of the housing and then dried. Secondary battery cell.

3. In Claim 1, The above gas generating material is in the form of a solution and is applied to the inner surface of the top cap and then dried. Secondary battery cell.

4. In Claim 1, The above gas generating material is in the form of a solution and is applied to the inner surface of the safety vent and then dried. Secondary battery cell.

5. In Claim 1, The above gas generating material is included in the electrolyte to decompose at a specific temperature to generate gas, Secondary battery cell.

6. In Claim 1, The above safety vent forms a circular closed loop, Secondary battery cell.

7. In Claim 6, The above safety vent is, Formed with a thickness thinner than the surrounding area of ​​the housing cover so that it can be easily broken when the internal pressure of the housing increases to a certain level, Secondary battery cell.

8. In Claim 1, The above secondary battery cell is, cylindrical secondary battery cell or prismatic secondary battery cell, Secondary battery cell.

9. In Claim 1, The above electrode assembly is, Made of a jelly-roll type Secondary battery cell.

10. A secondary battery cell according to any one of claims 1 to 9, and a pack housing in which a plurality of secondary battery cells are provided and housed. Secondary battery pack.

11. Characterized by including a secondary battery cell according to claim 1, automobile.

12. Characterized by including a secondary battery pack according to claim 10, automobile.

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