Secondary battery

Abstract

Secondary battery (1), comprising: an electrode assembly (100) in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately stacked with a separator arranged between them; a positive electrode tab (200) which is electrically connected to the plurality of positive electrode plates; a negative electrode tab (300) which is electrically connected to the plurality of negative electrode plates; a bag (400) containing an adhesive section (410) formed by joining a first section (411) and a second section (412) together to define a receiving space (S) for receiving the electrode assembly (100) therein and to seal the receiving space (S), while the positive electrode tab (200) and the negative electrode tab (300) are exposed to the outside; and a venting element (500) arranged between the first section (411) and the second section (412), wherein the venting element (500) opens at least part of the adhesive section (410) to connect the receiving chamber (S) to the outside of the bag (400) when a temperature inside the receiving chamber (S) becomes a predetermined temperature or higher and a pressure of the receiving chamber (S) increases.

Description

BACKGROUND OF THE INVENTION 1. Area

[0001] The present disclosure relates to a secondary battery and, more precisely, a secondary battery configured to release gas within a bag to a predetermined position of the bag. 2. Description of the related technology

[0002] The secondary battery is configured such that a casing surrounds an electrode assembly containing a positive electrode plate, a negative electrode plate and a separator, and is designed as a pouch-like secondary battery or a prismatic secondary battery depending on the type of casing.

[0003] In the bag-like secondary battery, the temperature inside the bag rises during charging or discharging, and with rising temperature inside the bag, the pressure inside the bag also rises due to gas produced by evaporation of the electrolyte.

[0004] If the temperature inside the bag rises rapidly at this time, heat is generated by a chemical reaction between the electrolyte and the electrodes, and if a relatively large amount of heat is generated, the secondary battery may be subject to thermal runaway.

[0005] To solve this problem, a bag with a gas outlet was developed to release the gas absorbed inside the bag to the outside. However, in the conventional bag, the position of the gas outlet is not specified. Therefore, if several secondary batteries are arranged adjacent to each other, the gas released from the gas outlet in any one of the secondary batteries could be expelled towards a neighboring secondary battery.

[0006] In short, if gas at a high temperature is expelled towards a neighboring secondary battery, the secondary battery exposed to the gas can experience a temperature increase and be subject to thermal runaway, and as a result, heat can spread between the several neighboring secondary batteries, causing several secondary batteries to be subject to thermal runaway.

[0007] Accordingly, it is necessary to develop a secondary battery that contains a bag capable of specifying the position of the gas outlet, so that the direction of gas release can be controlled. SUMMARY OF THE INVENTION

[0008] One purpose of the present disclosure is to provide a secondary battery in which the formation position of a gas outlet can be specified.

[0009] The secondary battery according to the present disclosure can be widely used in the field of green technology, such as electric vehicles. Additionally, the secondary battery according to the present disclosure can be applied to environmentally friendly electric and hybrid vehicles by suppressing air pollution and greenhouse gas emissions to prevent climate change.

[0010] As a technical means of solving the technical problems described above, a secondary battery according to an embodiment of the present disclosure includes: an electrode assembly in which a plurality of positive electrode plates and a plurality of negative electrode plates are stacked alternately with a separator between them; a positive electrode tab electrically connected to the plurality of positive electrode plates; a negative electrode tab electrically connected to the plurality of negative electrode plates; a pouch containing an adhesive section formed by joining a first section and a second section together to define a receiving space for receiving the electrode assembly therein and to seal the receiving space, while the positive electrode tab and the negative electrode tab are exposed to the outside; and A venting element arranged between the first section and the second section, wherein the venting element can open at least part of the adhesive section to connect the receiving chamber to the outside of the bag when a temperature inside the receiving chamber reaches a predetermined temperature or higher and a pressure of the receiving chamber increases.

[0011] Additionally, the venting element can include a body section provided in a longitudinally extending plate shape and a flow path section that expands when a fluid is introduced into it and forms a flow path connecting one end and the other end in the longitudinal direction of the body section, wherein one end of the flow path section may be exposed longitudinally to the receiving space and the other end of the flow path section may be arranged longitudinally at a position spaced a predetermined distance from an outer circumferential edge of the adhesive section.

[0012] Additionally, the cross-sectional area of ​​the flow path perpendicular to the longitudinal direction can decrease or remain constant from one end of the flow path section in the longitudinal direction to the other end of the flow path section in the longitudinal direction.

[0013] Additionally, the body section can be made of a heat-shrinkable material whose volume decreases when a temperature reaches or exceeds the predetermined temperature.

[0014] Additionally, the width of the venting element can decrease or remain constant perpendicular to the longitudinal direction from one end of the venting element in the longitudinal direction to the other end of the venting element in the longitudinal direction.

[0015] Additionally, the body section may be made of Mylar.

[0016] Additionally, the venting element may further include an extension section formed in a tube-like shape, having a passage that penetrates the interior of it along the longitudinal direction, with one end of it coupled to the flow path section to connect the receiving space to the flow path section.

[0017] Additionally, the cross-sectional area of ​​the passage can increase or remain constant perpendicular to the longitudinal direction from one end of the passage to the other end of the passage.

[0018] A method for manufacturing a secondary battery according to an embodiment of the present disclosure may include: a manufacturing step for producing an electrode assembly electrically connected to a positive electrode tab and a negative electrode tab; a receiving step for receiving the electrode assembly in a receiving space formed within a bag; a placement step for arranging a venting element between a first section and a second section of the bag;and an adhesive step for joining the first section and the second section to form an adhesive section to seal the receiving chamber while the positive electrode tab and the negative electrode tab are exposed to the outside, wherein the venting element can open at least part of the adhesive section to connect the receiving chamber to the outside of the bag when a temperature inside the receiving chamber reaches a predetermined temperature or higher and a pressure of the receiving chamber increases.

[0019] Additionally, the venting element can include a body section formed in a plate shape extending in a longitudinal direction and a flow path section which expands when a fluid is introduced into it and forms a flow path connecting one end and the other end in the longitudinal direction of the body section, wherein one end of the flow path section may be exposed in the longitudinal direction to the receiving space and the other end of the flow path section may be arranged in the longitudinal direction at a position spaced a predetermined distance from an outer circumferential edge of the adhesive section.

[0020] Additionally, the cross-sectional area of ​​the flow path perpendicular to the longitudinal direction can decrease or remain constant from one end of the flow path section in the longitudinal direction to the other end of the flow path section in the longitudinal direction.

[0021] Additionally, the body section can be made of a heat-shrinkable material whose volume decreases when a temperature reaches or exceeds the predetermined temperature.

[0022] Additionally, the venting element may further include an extension section formed in a tube-like shape, having a passage that penetrates the interior of it along the longitudinal direction, with one end of it coupled to the flow path section to connect the receiving space to the flow path section.

[0023] Additionally, the body section can be formed by joining two foil-shaped materials together with an adhesive.

[0024] Additionally, the adhesive may contain at least one acrylic-based material and one silicone-based material.

[0025] Specific details of other embodiments for solving the problems described above are included in the description of the invention and the drawings.

[0026] According to the means described above for solving the problems of the present disclosure, the secondary battery according to the present disclosure provides an effect in which the formation position of a gas outlet through the venting element can be specified.

[0027] Additionally, if the temperature inside the bag reaches a predetermined temperature or higher, an effect is provided in which gas release can be easily formed.

[0028] Furthermore, by the method for manufacturing a secondary battery according to the present disclosure, a secondary battery can be manufactured which is able to specify the origin position of a gas outlet through the venting element. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective expanded view of a secondary battery according to an embodiment of the present disclosure. Fig. Figure 2 is a view showing the secondary battery. Fig. Figure 3 is a view that represents a venting element. Fig. Figure 4 is a view showing the venting element in which a flow path is formed. Fig. Figure 5 is a view showing a foil-shaped material forming a body section. Fig. Figure 6 is an enlarged view of part A of Fig. 1, which shows a condition in which an adhesive section is opened by gas moving through the flow path formed in the venting element. Fig. Figure 7 is an enlarged view of Part A of Fig. 1, which shows a state in which an adhesive section is opened by gas moving through the flow path formed in the vent element made of a heat-shrinkable material, according to an example. Fig. Figure 8 is an enlarged view of Part A of Fig. 1, which shows a state in which an adhesive section is opened by gas moving through the flow path formed in the vent element made of a heat-shrinkable material, according to another example. Fig. 9 is an enlarged view of part A of Fig. 1, which shows the venting element that includes an extension section. Fig. Figure 10 is a flowchart illustrating a method for manufacturing a secondary battery according to the present disclosure. DETAILED DESCRIPTION

[0029] Embodiments of the present application are described in detail below with reference to the accompanying drawings, so that the person skilled in the art, to whom the present application applies, can easily carry out the invention. However, the present application can be implemented in various different forms and is not limited to the embodiments described herein. For the sake of clarity, parts of the drawings that are irrelevant to the description have been omitted, and the same reference numerals denote the same elements throughout the entire description.

[0030] When a part is described as being “connected” to another part throughout the entire description, this includes not only cases where they are “directly connected” but also cases where they are “electrically connected” to another element placed in between.

[0031] If, in the entire description, an element is described as being "on" another element, this includes not only cases where the element is in contact with the other element, but also cases where another element is located between the two elements.

[0032] If, in the overall description, a part is described as "containing" a component, unless otherwise stated, it does not exclude other components, but may also contain other components.

[0033] Throughout this description, terms of extent such as "approximately" and "essentially" are used to indicate values ​​that include manufacturing and material tolerances inherent in the specified meaning or values ​​close to them, and are used to prevent an unscrupulous infringer from gaining unfair advantages from precise or absolute numerical disclosures provided for the purpose of understanding the invention.

[0034] Throughout the description, the expressions of extent "the step of~" or "a step of~" do not mean "a step for~".

[0035] Preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings and the following description. However, the present disclosure is not limited to the embodiments described herein and can be implemented in other forms. The same reference numerals refer to the same elements throughout the entire description.

[0036] The configuration of a secondary battery according to one embodiment of the present disclosure is described below.

[0037] Fig. Figure 1 is a perspective expanded view of a secondary battery according to an embodiment of the present disclosure.

[0038] With reference to Fig. 1 The secondary battery 1 contains an electrode assembly 100, a positive electrode tab 200, a negative electrode tab 300, a bag 400 and a venting element 500.

[0039] First, the electrode assembly 100 is described.

[0040] The electrode assembly 100 can be formed by alternately stacking a plurality of positive electrode plates and a plurality of negative electrode plates with a separator placed between them, and each of the positive electrode plate and the negative electrode plate is formed with an uncoated section extending therefrom.

[0041] The positive electrode plate can function as a positive electrode and can be formed by applying a first active electrode material, such as a transition metal oxide, to a first electrode current collector formed from a metal foil, such as aluminum.

[0042] The positive electrode plate contains a first uncoated electrode section, which is an area where the first active electrode material is not applied, and the first uncoated electrode section can serve as a current flow path between the positive electrode plate and the outside and can also form a positive electrode tab 200 described later.

[0043] The negative electrode plate can function as a negative electrode and can be formed by applying a second active electrode material, such as graphite or carbon, to a second electrode current collector formed from a metal foil, such as copper or nickel.

[0044] The negative electrode plate contains a second uncoated electrode section, which is an area where the second active electrode material is not applied, and the second uncoated electrode section can serve as a current flow path between the negative electrode plate and the outside and can also form a negative electrode tab 300 described later.

[0045] The separator is positioned between the positive and negative electrode plates to prevent short circuits and allow the movement of lithium ions. The separator can be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene.

[0046] Next, the positive electrode tab 200 will be described.

[0047] With reference to Fig. 1. The positive electrode tab 200 can be electrically connected to the multitude of positive electrode plates.

[0048] The positive electrode tab 200 can be formed as a separate element coupled to the first uncoated electrode section, or can be formed by the first uncoated electrode section as described above.

[0049] Next, the negative electrode tab 300 will be described.

[0050] With reference to Fig. 1. The negative electrode tab 300 can be electrically connected to the multitude of negative electrode plates.

[0051] The negative electrode tab 300 can be formed as a separate element coupled to the second uncoated electrode section, or can be formed by the second uncoated electrode section as described above.

[0052] Next, bag 400 will be described.

[0053] The bag 400 can serve as an external element that accommodates the electrode assembly 100.

[0054] Fig. Figure 2 is a view showing the secondary battery.

[0055] Specifically, as in Fig. As shown in Figure 1, the bag 400 has a receiving chamber S formed therein to receive the electrode assembly 100, and can, as shown in Fig. Figure 2 shows an adhesive section 410 which is formed by joining a predetermined first section 411 and a predetermined second section 412 to seal the receiving space S, while the positive electrode tab 200 and the negative electrode tab 300 are exposed to the outside.

[0056] Thus, if the first section 411 and the second section 412 are connected in a state in which the electrode assembly 100 is received in the receiving space S, the receiving space S can be sealed.

[0057] Next, the venting element 500 will be described.

[0058] As in Fig. As shown in Figure 1, the venting element 500 can be arranged between the first section 411 and the second section 412, and at least one or more venting elements 500 can be arranged between the first section 411 and the second section 412.

[0059] The venting element 500 can perform a function of opening at least part of the adhesive section 410 to connect the receiving chamber S to the outside of the bag 400 when the temperature of the receiving chamber S reaches a predetermined temperature or higher and the pressure of the receiving chamber S increases.

[0060] This means that when the temperature of the receiving chamber S increases, the venting element 500 can perform a function of directing the release of gas that is received in the receiving chamber S (hereinafter referred to as "gas") to be released only through the position of the adhesive section 410 in which the venting element 500 is located.

[0061] At this point, the predetermined temperature may be a temperature that causes thermal runaway of the secondary battery, and may be a temperature in the range of 126 °C to 150 °C.

[0062] Fig. Figure 3 is a view that represents a venting element.

[0063] As in Fig. As shown in Figure 3, the venting element 500 contains a body section 510 and a flow path section 520.

[0064] Body section 510 can be formed in a plate shape extending in a longitudinal direction and can be made of different materials.

[0065] For example, body section 510 can be made of a heat-shrinkable material whose volume decreases when a temperature reaches a predetermined temperature or higher.

[0066] In particular, body section 510 may be made of Mylar. Generally, the temperature that causes thermal runaway of a secondary battery is in the range of 126°C to 150°C, and since Mylar has a heat-shrinkable temperature in the range of 126°C to 150°C, if body section 510 is made of Mylar, it will shrink when the temperature of the secondary battery reaches the temperature that causes thermal runaway.

[0067] Fig. Figure 4 is a view showing the venting element in which a flow path is formed.

[0068] As in Fig. As shown in Figure 4, the flow path section 520 can expand when a fluid is introduced into it, forming a flow path 530 that connects one end and the other end of the body section 510 in the longitudinal direction.

[0069] The shape of the flow path 530 is not restricted; however, as in Fig. 4 shown, preferably that the cross-sectional area of ​​the flow path 530 decreases or remains constant perpendicular to the longitudinal direction from one end of the flow path section 520 in the longitudinal direction to the other end of the flow path section 520 in the longitudinal direction.

[0070] Fig. Figure 5 is a view showing a foil-shaped material forming a body section.

[0071] Meanwhile, as in Fig. Figure 5 shows that the body section 510 is formed by joining two foil-shaped materials 501 and 502.

[0072] In particular, the body section 510 can be formed by applying an adhesive to a section B, which is a different area than the section in which the flow path section 520 of the two foil-shaped materials 501 and 502 is to be formed, and then by joining the two foil-shaped materials 501 and 502 together.

[0073] At this stage, the adhesive for joining the two foil-shaped materials 501 and 502 may contain at least one of an acrylic-based material and one of a silicone-based material; however, the composition of the adhesive is not limited thereto.

[0074] Fig. Figure 6 is an enlarged view of part A of Fig. 1, which shows a state in which an adhesive section is opened by a gas moving through the flow path formed in the venting element.

[0075] As in Fig. As shown in Figure 6, in the venting element 500 formed above, one end of the flow path section 520 in the longitudinal direction to the receiving space S can be exposed, and the other end of the flow path section 520 in the longitudinal direction can be arranged at a position that is spaced a predetermined distance L1 from the outer circumferential edge of the adhesive section 410.

[0076] At this point, the shortest length L2 of the adhesive section 410 from its outer circumferential edge to the receiving space S can be 1.5 cm or more and 4.5 cm or less, the predetermined distance L1 can be 0.3 cm or more and 0.5 cm or less, the longitudinal length L3 of the venting element 500 can be 1 cm or more and 4 cm or less, and the width L4 can be 0.5 cm or more and 3 cm or less in one lateral direction. However, the configuration of the adhesive section length L2, the predetermined distance L1, the longitudinal length L3 of the venting element 500, and the width L4 is not limited to these.

[0077] As in Fig. As shown in Figure 6, when the temperature of the receiving chamber S reaches a predetermined temperature or higher and the pressure of the receiving chamber S increases, gas is introduced into the interior of the flow path section 520 of the venting element 500, thereby forming the flow path 530, and the gas moving through the flow path 530 presses at least one part P of the adhesive section 410 adjacent to the flow path 530, thereby opening at least one part P of the adhesive section 410.

[0078] If the flow path 530 is designed such that the cross-sectional area of ​​the flow path 530 decreases or remains constant perpendicular to the longitudinal direction from one end of the flow path section 520 in the longitudinal direction to the other end, then, according to Bernoulli's principle, at this time the force with which the gas moving through the flow path 530 presses at least a part P of the adhesive section 410 increases, so that at least a part P of the adhesive section 410 can be easily opened.

[0079] Meanwhile, the venting element 500 can be designed such that at least one part P of the adhesive section 410 can be opened more easily.

[0080] Fig. Figure 7 is an enlarged view of Part A of Fig. 1, which shows a condition in which an adhesive section is opened by gas moving through the flow path formed in the vent element made of a heat-shrinkable material, according to an example.

[0081] For example, the venting element 500 can be described with reference to Fig. 7 is formed from a heat-shrinkable material and is arranged on the adhesive section 410, and it can allow gas to move through the flow path 530.

[0082] Since at this time the temperature of the receiving chamber S becomes a predetermined temperature or higher, and the temperature of the gas moving through the flow path 530 also becomes a predetermined temperature or higher, the venting element 500 absorbs heat from the receiving chamber S and the flow path 530 and contracts, thereby reducing its longitudinal length and width.

[0083] When the venting element 500 contracts, as described in Fig. Figure 7 shows that a gap is created in the longitudinal direction between the adhesive section 410 and the venting element 500 adjacent to the other end of the venting element 500, and gaps are also created in the width direction adjacent to both ends of the venting element 500 between the adhesive section 410 and the venting element 500.

[0084] Accordingly, the adhesive strength of the adhesive section 410 adjacent to the venting element 500 is weakened, and at least a part P of the adhesive section 410 adjacent to the venting element 500 can be opened more easily by the pressure of the gas moving through the flow path 530 of the venting element 500.

[0085] Fig. Figure 8 is an enlarged view of Part A of Fig. 1, which shows a state in which an adhesive section is opened by gas moving through the flow path formed in the vent element made of a heat-shrinkable material, according to another example.

[0086] In another example, the venting element 500 can be described with reference to Fig. 8 made of a heat-shrinkable material and arranged on the adhesive section 410. The venting element 500 can be designed such that its width decreases or remains constant perpendicular to the longitudinal direction from one end of the venting element 500 to the other end, allowing gas to move through the flow path 530.

[0087] Since at this time the temperature of the receiving chamber S becomes a predetermined temperature or higher, and the temperature of the gas moving through the flow path 530 also becomes a predetermined temperature or higher, the venting element 500 absorbs heat from the receiving chamber S and the flow path 530 and contracts, thereby reducing its longitudinal length and width.

[0088] When the venting element 500 contracts, as described in Fig. Figure 8 shows that a gap is created in the longitudinal direction between the adhesive section 410 and the venting element 500 adjacent to the other end of the venting element 500, and gaps are also created in the width direction between the adhesive section 410 and the venting element 500 adjacent to both ends of the venting element 500.

[0089] Meanwhile, as the width of the venting element 500 decreases or remains constant perpendicular to the longitudinal direction from one end of the venting element 500 to the other end, the gap created between the adhesive section 410 and the venting element 500 adjacent to the other end of the venting element 500 in the longitudinal direction approaches at least a part P of the adhesive section 410.

[0090] Accordingly, the adhesive strength of the adhesive section 410 adjacent to the venting element 500, in particular the adhesive strength of the adhesive section 410 adjacent to at least a part P of the adhesive section 410, is weakened, and at least a part P of the adhesive section 410 adjacent to the venting element 500 can be opened more easily by the pressure of the gas moving through the flow path 530 of the venting element 500.

[0091] Fig. 9 is an enlarged view of part A of Fig. 1, which shows the venting element that includes an extension section.

[0092] In yet another example, the venting element 500 can be used with reference to Fig. 9 be formed in a tube-like shape which has a passage penetrating the interior of it along the longitudinal direction, and may further include an extension section 540, one end of which is coupled to the flow path section 520 to connect the receiving space S to the flow path section 520.

[0093] If the venting element 500 includes the extension section 540 as described above, gas can be introduced more easily through the passage of the extension section 540 into the flow path section 520, so that at least part P of the adhesive section 410 can be opened more easily.

[0094] The extension section 540 only needs to have a passage formed along its longitudinal direction, and its shape is not particularly restricted.

[0095] For example, the extension section 540 can be configured such that the cross-sectional area of ​​the passage increases or remains constant perpendicular to the longitudinal direction from one end of the passage to the other. This means that the passage can be configured such that, according to Bernoulli's principle, the gas moving towards the flow path section 520 will have a higher pressure as it approaches the flow path section 520.

[0096] The following describes a method for manufacturing a secondary battery of the present disclosure.

[0097] The secondary battery produced by the method for producing a secondary battery according to the present disclosure may be the same as the secondary battery according to an embodiment of the present disclosure.

[0098] Fig. Figure 10 is a flowchart illustrating a method for manufacturing a secondary battery according to the present disclosure.

[0099] With reference to Fig. 10 contains the procedure for manufacturing the secondary battery a manufacturing step S100, a receiving step S200, a placement step S300 and a bonding step S400.

[0100] First, manufacturing step S100 is described.

[0101] Manufacturing step S100 is a step to manufacture an electrode assembly 100 which is electrically connected to a positive electrode tab 200 and a negative electrode tab 300.

[0102] Since the specific configurations of the electrode assembly 100, the positive electrode tab 200 and the negative electrode tab 300 are the same as those of the electrode assembly 100, the positive electrode tab 200 and the negative electrode tab 300 of the secondary battery 1 mentioned above, detailed descriptions of them are omitted below.

[0103] Next, the recording step S200 will be described.

[0104] The receiving step S200 is a step to receive the electrode assembly 100 in a receiving space S formed within the bag 400.

[0105] Since the specific configuration of bag 400 is the same as that of bag 400 of the aforementioned secondary battery 1, detailed descriptions of it are omitted below.

[0106] Next, the placement step S300 will be described.

[0107] The placement step S300 is a step to arrange the venting element 500 between a predetermined first section 411 of the bag 400 and a predetermined second section 412 of the bag 400.

[0108] At this point, the venting element 500 can be configured to open at least part of the adhesive section 410 to connect the receiving chamber S to the outside of the bag 400 when the temperature of the receiving chamber S reaches a predetermined temperature or higher and the pressure of the receiving chamber S increases.

[0109] Since the specific configuration of the venting element 500 and the specific arrangement of the venting element 500 placed on the adhesive section 410 are the same as those of the venting element 500 and the venting element 500 placed on the adhesive section 410 of the secondary battery 1 mentioned above, detailed descriptions thereof are omitted below.

[0110] Next, the gluing step S400 will be described.

[0111] The bonding step S400 is a step to join the first section 411 of the bag 400 and the second section 412 of the bag 400 to form the bonding section 410 to seal the receiving space S while the positive electrode flap 200 and the negative electrode flap 300 are exposed to the outside.

[0112] Since the specific configurations of the first section 411, the second section 412 and the adhesive section 410 of the bag 400 are the same as those of the first section 411, the second section 412 and the adhesive section 410 of the bag 400 of the secondary battery 1 mentioned above, detailed descriptions thereof are omitted below.

[0113] The operation and effects of the secondary battery according to one embodiment of the present disclosure are described below.

[0114] After the electrode assembly 100 is received in the receiving space S of the bag 400, the first section 411 and the second section 412 of the bag 400 are joined to form the adhesive section 410, thereby sealing the receiving space S.

[0115] At this point, the venting element 500 is arranged at a predetermined position between the first section 411 and the second section 412.

[0116] When the temperature of the receiving chamber S increases, the venting element 500 allows the gas received in the receiving chamber S to move through the flow path 530 formed therein, and the gas moved through the flow path 530 opens at least a part P of the adhesive section 410 to connect the receiving chamber S to the outside of the bag 400.

[0117] Meanwhile, the venting element 500 can be made of a heat-shrinkable material, and if the venting element 500 is made of a heat-shrinkable material, the venting element 500 will be heated and contracted when the temperature of the receiving chamber S increases.

[0118] Accordingly, a gap is created between the venting element 500 and the adhesive section 410, and the adhesive strength of the adhesive section 410 adjacent to the venting element 500 is weakened, so that at least a part P of the adhesive section 410 adjacent to the venting element 500 can be opened more easily.

[0119] As described above, the secondary battery according to the present disclosure provides an effect in which the formation position of a gas outlet can be specified by the venting element.

[0120] Additionally, an effect is provided where the gas outlet can be easily formed when the temperature inside the bag reaches a predetermined temperature or higher.

[0121] In addition, the method for producing a secondary battery according to the present disclosure provides an effect in which a secondary battery can be produced which is able to specify the origin position of a gas outlet through the venting element.

[0122] The person skilled in the art will understand that the multitude of exemplary embodiments described above are specific examples of the following aspects.

[0123] Aspect 1. Secondary battery, comprising: an electrode assembly in which a plurality of positive electrode plates and a plurality of negative electrode plates are arranged alternately stacked with a separator between them; a positive electrode tab electrically connected to the plurality of positive electrode plates; a negative electrode tab electrically connected to the plurality of negative electrode plates; a bag containing an adhesive section formed by joining a first section and a second section together to define a receiving space for receiving the electrode assembly therein and to seal the receiving space, while the positive electrode tab and the negative electrode tab are exposed to the outside;and a venting element arranged between the first section and the second section, wherein the venting element opens at least a part of the adhesive section to connect the receiving chamber to the outside of the bag when a temperature inside the receiving chamber reaches a predetermined temperature or higher and a pressure in the receiving chamber increases.

[0124] Aspect 2. Secondary battery according to Aspect 1, wherein the venting element comprises: a body section having a plate shape extending in a longitudinal direction; and a flow path section comprising a flow path which expands when a fluid is introduced into it and which connects one end and the other end in the longitudinal direction of the body section, wherein one end of the flow path section is exposed longitudinally to the receiving space and the other end of the flow path section is arranged longitudinally at a position spaced a predetermined distance from an outer circumferential edge of the adhesive section.

[0125] Aspect 3. Secondary battery according to aspect 2, wherein a cross-sectional area of ​​the flow path decreases or remains constant perpendicular to the longitudinal direction from one end of the flow path section in the longitudinal direction to the other end of the flow path section in the longitudinal direction.

[0126] Aspect 4. Secondary battery according to aspect 2 or 3, wherein the body section is formed from a heat-shrinkable material whose volume decreases when a temperature becomes the predetermined temperature or higher.

[0127] Aspect 5. Secondary battery according to one of the preceding aspects, wherein a width in a direction perpendicular to the longitudinal direction of the venting element decreases or remains constant from one end of the venting element in the longitudinal direction to the other end of the venting element in the longitudinal direction.

[0128] Aspect 6. Secondary battery according to one of aspects 2 to 5, wherein the body section is formed from Mylar.

[0129] Aspect 7. Secondary battery according to one of aspects 2 to 6, wherein the venting element further includes an extension section formed in a tube-like shape having a passage penetrating the interior of it along the longitudinal direction, one end of it being coupled to the flow path section to connect the receiving space to the flow path section.

[0130] Aspect 8. Secondary battery according to aspect 7, wherein a cross-sectional area of ​​the passage perpendicular to the longitudinal direction from one end of the passage to the other end of the passage increases or remains constant.

[0131] The above description of the present disclosure serves illustrative purposes, and the person skilled in the art, to whom the present disclosure applies, will understand that various modifications to it can be made in other specific forms without altering the technical spirit or essential features of the present disclosure. Therefore, the embodiments described above are to be understood in all aspects as illustrative and not as limiting. For example, any component described as being implemented in a single form may be implemented in a divided manner, and likewise, components described as being divided may be implemented in a combined form.

[0132] The scope of this disclosure is defined by the following claims and not by the preceding detailed description, and it should be interpreted such that any modifications or variations derived from the meaning, scope and equivalents of the claims fall within the scope of this disclosure.

[0133] The present disclosure relates to a secondary battery. The secondary battery comprises: an electrode assembly; a positive electrode tab; a negative electrode tab; a bag containing an adhesive section formed by joining a first section and a second section together to define a receiving space for receiving the electrode assembly and to seal the receiving space, while the positive electrode tab and the negative electrode tab are exposed to the outside; and a venting element arranged between the first section and the second section, the venting element being configured to open at least a portion of the adhesive section to connect the receiving space to the outside of the bag.

Claims

[1] Secondary battery (1), comprising: an electrode assembly (100) in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately stacked with a separator arranged between them; a positive electrode tab (200) which is electrically connected to the plurality of positive electrode plates; a negative electrode tab (300) which is electrically connected to the plurality of negative electrode plates; a bag (400) containing an adhesive section (410) formed by joining a first section (411) and a second section (412) together to define a receiving space (S) for receiving the electrode assembly (100) therein and to seal the receiving space (S), while the positive electrode tab (200) and the negative electrode tab (300) are exposed to the outside; and a venting element (500) arranged between the first section (411) and the second section (412), wherein the venting element (500) opens at least part of the adhesive section (410) to connect the receiving chamber (S) to the outside of the bag (400) when a temperature inside the receiving chamber (S) becomes a predetermined temperature or higher and a pressure of the receiving chamber (S) increases. [2] Secondary battery (1) according to claim 1, wherein the venting element (500) includes: a body section (510) that has a plate shape extending in a longitudinal direction; and a flow path section (520) which contains a flow path (530) which expands when a fluid is introduced into it and which connects one end and the other end of the body section (510) in the longitudinal direction, wherein one end of the flow path section (520) is exposed in the longitudinal direction to the receiving space (S) and the other end of the flow path section (520) is arranged in the longitudinal direction at a position that is spaced a predetermined distance (L1) from an outer circumferential edge of the adhesive section (410). [3] Secondary battery (1) according to claim 2, wherein a cross-sectional area of ​​the flow path (530) decreases or remains constant perpendicular to the longitudinal direction from one end of the flow path section (520) in the longitudinal direction to the other end of the flow path section (520) in the longitudinal direction. [4] Secondary battery (1) according to claim 2 or 3, wherein the body section (510) is formed from a heat-shrinkable material, the volume of which decreases when a temperature becomes the predetermined temperature or higher. [5] Secondary battery (1) according to one of the preceding claims, wherein a width (L4) decreases or remains constant in a direction perpendicular to the longitudinal direction of the venting element (500) from one end of the venting element (500) in the longitudinal direction to the other end of the venting element (500) in the longitudinal direction. [6] Secondary battery (1) according to any one of claims 2 to 5, wherein the body section (510) is made of Mylar. [7] Secondary battery (1) according to any one of claims 2 to 6, wherein the venting element (500) further comprises an extension section (540) formed in a tube-like shape having a passage penetrating the interior of it along the longitudinal direction, wherein one end of it is coupled to the flow path section (520) to connect the receiving space (S) to the flow path section (520). [8] Secondary battery (1) according to claim 7, wherein a cross-sectional area of ​​the passage increases or remains constant perpendicular to the longitudinal direction from one end of the passage to the other end of the passage.

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