Pouch cell

Abstract

The application relates to the technical field of batteries, in particular to a soft package battery which comprises a pole piece assembly, an outer coating film and an exhaust assembly. The outer coating film is coated outside the pole piece assembly, and a gas collection area is formed on the side of the outer coating film which is not provided with a pole lug of the pole piece assembly. The exhaust assembly comprises a main valve body, an elastic member and a first gas-permeable liquid-blocking film. The main valve body is installed on the gas collection area, and is provided with a gas guide channel and a gas guide through hole. The gas guide channel is in communication with the inside of the gas collection area, and the gas guide channel is in communication with the outside of the gas collection area through the gas guide through hole. The first gas-permeable liquid-blocking film and the elastic member are sequentially arranged in the gas guide channel along the extension direction of the gas guide channel, and the first gas-permeable liquid-blocking film is connected with the main valve body through the elastic member. It can be seen that a part of the outer coating film is reserved on the side of the pole piece assembly as the gas collection area, and the exhaust assembly is installed on the gas collection area, so that the gas generated in the soft package battery can be regularly exhausted, and the cycle life and safety performance of the soft package battery are improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a pouch battery. Background Technology

[0002] Electrodeless sodium-ion batteries (AFSMBs) maximize energy density compared to typical sodium metal batteries by eliminating the presence of a metallic sodium anode in a given sodium-containing cathode configuration. However, the electrodeless design allows metallic sodium to deposit directly on the current collector, making it susceptible to reaction with the electrolyte. This reaction can lead to the generation of gases (such as H₂, CH₄, etc.) during cycling, storage, or under abnormal operating conditions. The accumulation of large amounts of gas inside the battery not only significantly impacts performance but also poses safety risks. Therefore, eliminating the gases generated during operation of electrodeless sodium-ion batteries to improve their cycle performance and safety has become an urgent problem to be solved. Utility Model Content

[0003] The purpose of this application is to provide a soft-pack battery that, to a certain extent, solves the technical problem of how to eliminate the gas generated during the operation of a negative electrode-less sodium-ion battery in order to improve its cycle performance and safety performance.

[0004] This application provides a soft-pack battery, including: an electrode assembly, an outer coating film, and a venting assembly; wherein, the outer coating film covers the outside of the electrode assembly, and a gas collecting area is formed on the side of the outer coating film of the electrode assembly where no tabs are formed, and the gas collecting area is used to collect the gas generated by the electrode assembly; the venting assembly is installed in the gas collecting area and is used to discharge the gas collected inside the gas collecting area; the venting assembly includes a main valve body, an elastic member, and a first gas-permeable liquid-resistant membrane, the main valve body is installed in the gas collecting area, and the main valve body forms a gas guiding channel and a gas guiding hole, and the gas guiding channel is connected to the inside of the gas collecting area, and the gas guiding channel is connected to the outside of the gas collecting area through the gas guiding hole;

[0005] The first gas-permeable liquid-resistant membrane and the elastic member are sequentially disposed within the gas-guiding channel along the extension direction of the gas-guiding channel. The first gas-permeable liquid-resistant membrane is connected to the main valve body through the elastic member. When the soft-pack battery does not vent, the first gas-permeable liquid-resistant membrane blocks the gas-guiding channel. When the soft-pack battery vents, the first gas-permeable liquid-resistant membrane is pushed open by the gas to open the gas-guiding channel for venting. The elastic member is used to reset the first gas-permeable liquid-resistant membrane to block the gas-guiding channel again.

[0006] In the above technical solution, the first breathable liquid-resistant membrane and the elastic member are arranged sequentially from the inside to the outside along the extension direction of the air guide channel; the exhaust assembly also includes a limiting member, which is disposed in the air guide channel and connected to the main valve body;

[0007] Along the extension direction of the air-conducting channel, the limiting member is disposed on the side of the first air-permeable liquid-resistant membrane away from the outer covering film, and when the soft-pack battery is not venting, the first air-permeable liquid-resistant membrane abuts against the limiting member, the limiting member is used to limit the first air-permeable liquid-resistant membrane, and causes the elastic member to be in a compressed state.

[0008] In any of the above technical solutions, the exhaust assembly further includes a second gas-permeable liquid-blocking membrane, which is disposed within the gas guiding channel. The first gas-permeable liquid-blocking membrane, the elastic member, and the second gas-permeable liquid-blocking membrane are sequentially arranged and connected from the inside to the outside along the extension direction of the gas guiding channel. The second gas-permeable liquid-blocking membrane is connected to the main valve body, and the porosity of the second gas-permeable liquid-blocking membrane is greater than that of the first gas-permeable liquid-blocking membrane.

[0009] In any of the above technical solutions, the second air-permeable liquid-blocking membrane is further described as a liquid-repellent microporous membrane.

[0010] In any of the above technical solutions, the diameter of the pores of the second gas-permeable liquid-blocking membrane is d2, and 0.1um≤d2≤1um.

[0011] In any of the above technical solutions, the thickness of the second air-permeable liquid-blocking membrane is t2, and 10um≤t2≤100um.

[0012] In any of the above technical solutions, a portion of the main valve body and the air guide hole thereon are disposed outside the gas collection area, another portion of the main valve body is disposed inside the gas collection area, and the elastic member and the first air-permeable liquid-resistant membrane are both disposed within the structure of the main valve body located inside the gas collection area.

[0013] In any of the above technical solutions, the main valve body further includes an air guide pipe, a mounting base, a valve seat, and a protective cover; wherein the air guide pipe and the mounting base are both disposed inside the gas collection area, and the air guide pipe is connected to the mounting base, and the mounting base is disposed close to the outer membrane relative to the air guide pipe.

[0014] The air guide channel is formed on the air guide pipe, the mounting base, and the valve seat, and the first gas-permeable liquid-resistant membrane and the elastic member are both disposed in the air guide channel within the mounting base; the mounting base has a mounting protrusion ring extending to the outside of the gas collection area, and the valve seat is connected to the mounting protrusion ring; the protective cover seals the opening end of the air guide channel of the valve seat; the air guide hole is formed on the side wall of the valve body.

[0015] In any of the above technical solutions, the air guide pipe is further described as an arc-shaped bend.

[0016] In any of the above technical solutions, the open end of the arc-shaped bend that is away from the mounting base is positioned toward the electrode assembly side.

[0017] In any of the above technical solutions, the arc of the curved pipe is α, and 30°≤α≤60°.

[0018] In any of the above technical solutions, the valve seat is further provided to be detachably threaded to the mounting protrusion ring.

[0019] In any of the above technical solutions, the protective cover and the valve seat are further connected by adhesive.

[0020] In any of the above technical solutions, the main valve body further includes a gasket, which is sleeved on the outside of the mounting protrusion ring and pressed between the valve body and the mounting seat.

[0021] In any of the above technical solutions, the first air-permeable liquid-blocking membrane is further described as a liquid-repellent microporous membrane.

[0022] In any of the above technical solutions, the diameter of the pores of the first gas-permeable liquid-blocking membrane is d1, and 0.1um≤d1≤1um.

[0023] In any of the above technical solutions, the thickness of the first gas-permeable liquid-blocking membrane is t1, and 10um≤t1≤100um.

[0024] In any of the above technical solutions, further, along the length direction of the electrode assembly, at least one end of the electrode assembly is formed with the tab; along the width direction of the electrode assembly, one side of the electrode assembly is provided with the gas collection area.

[0025] In any of the above technical solutions, the main valve body is further installed on the large surface of the gas collection area, and the main valve body is arranged along the thickness direction of the soft-pack battery. When the soft-pack battery is placed in a horizontal state, the main valve body is installed on the large surface at the top of the gas collection area, and the first gas-permeable liquid-resistant membrane is disposed below the elastic member.

[0026] Compared with the prior art, the beneficial effects of this application are as follows:

[0027] This application provides a novel soft-pack battery in which a portion of the outer film is reserved on the side of the electrode assembly as a gas collection area, and an exhaust component is installed in this gas collection area, thereby periodically venting the gas generated inside the soft-pack battery, thereby improving the cycle life and safety performance of soft-pack batteries, such as negative electrode-free sodium batteries. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 An exploded view of the exhaust assembly provided in the embodiments of this application;

[0030] Figure 2 This is a schematic diagram of the structure of a pouch battery provided in an embodiment of this application;

[0031] Figure 3 This is a partially enlarged structural diagram of the soft-pack battery provided in an embodiment of this application.

[0032] Figure label:

[0033] 1-Electrode assembly, 11-Electrode tab, 2-Outer coating, 31-Gas collection area, 311-Large surface, 4-Exhaust assembly, 41-Main valve body, 411-Gas guide pipe, 4111-First gas guide channel, 412-Mounting base, 4121-Second gas guide channel, 413-Mounting protrusion ring, 414-Valve seat, 4141-Third gas guide channel, 4142-Gas guide hole, 415-Protective cover, 42-Elastic component, 43-First gas-permeable liquid-resistant membrane, 44-Limiting component, 45-Second gas-permeable liquid-resistant membrane, 46-Washer, a-Width direction of electrode assembly, b-Length direction of electrode assembly, c-Thickness direction of pouch battery. Detailed Implementation

[0034] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0035] The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application.

[0036] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0037] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] The following reference Figures 1 to 3 This application describes a pouch cell battery according to some embodiments.

[0040] See Figures 1 to 3As shown, an embodiment of this application provides a soft-pack battery, including: an electrode assembly 1, an outer film 2, and an exhaust assembly 4; wherein, the outer film 2 covers the outside of the electrode assembly 1, and a gas collecting area 31 is formed on the side of the outer film 2 located on the electrode assembly 1 where no tab 11 is formed, and the gas collecting area 31 is used to collect the gas generated by the electrode assembly 1, that is, a part of the outer film 2 is directly used as a gas bag to collect the gas generated by the electrode assembly 1, which is more convenient to manufacture; the exhaust assembly 4 is installed in the gas collecting area 31 and is used to discharge the gas collected inside the gas collecting area 31; the exhaust assembly 4 includes a main valve body 41, an elastic member 42, and a first gas-permeable liquid-resistant membrane 43, the main valve body 41 is installed in the gas collecting area 31, and the main valve body 41 forms a gas guiding channel and a gas guiding hole 4142, and the gas guiding channel is connected to the inside of the gas collecting area 31, and the gas guiding channel is connected to the outside of the gas collecting area 31 through the gas guiding hole 4142;

[0041] The first gas-permeable liquid-blocking membrane 43 and the elastic member 42 are sequentially disposed in the gas-guiding channel along the extension direction of the gas-guiding channel. The first gas-permeable liquid-blocking membrane 43 is connected to the main valve body 41 through the elastic member 42. When the soft-pack battery does not vent, the first gas-permeable liquid-blocking membrane 43 blocks the gas-guiding channel. When the soft-pack battery vents, the first gas-permeable liquid-blocking membrane 43 is pushed open by the gas to open the gas-guiding channel for venting. The elastic member 42 is used to reset the first gas-permeable liquid-blocking membrane 43 to block the gas-guiding channel again.

[0042] Based on the structure described above, the usage process of the venting assembly 4 of the soft-pack battery provided in this application is roughly as follows: When the electrode assembly 1 generates gas, and the gas in the gas collection area 31 reaches a certain pressure, the first gas-permeable liquid-resistant membrane 43 is pushed open by the gas, so that the first gas-permeable liquid-resistant membrane 43 no longer blocks the gas guiding channel. The gas passes through the gas guiding channel and is finally discharged to the outside of the outer covering membrane 2 through the gas guiding hole 4142, thereby realizing venting. When the gas pressure drops to a certain value, the elastic member 42 pulls the first gas-permeable liquid-resistant membrane 43 to reset, so that the first gas-permeable liquid-resistant membrane 43 blocks the gas guiding channel again.

[0043] As can be seen, this application provides a novel soft-pack battery, in which a portion of the outer film 2 is reserved on the side of the electrode assembly 1 as a gas collection area 31, and an exhaust assembly 4 is installed in this gas collection area 31, so as to periodically exhaust the gas generated inside the soft-pack battery, thereby improving the cycle life and safety performance of the soft-pack battery, such as a negative electrode-free sodium battery.

[0044] Furthermore, preferably, the elastic member 42 is a spring, but of course, it is not limited to this.

[0045] It should be noted that the pouch battery provided in this application is not limited to negative electrode-free sodium-ion batteries (AFSMBs), but can also be other types of pouch batteries, depending on actual needs. In other words, the exhaust component 4 provided in this application is not limited to negative electrode-free sodium-ion batteries, but can also be applied to other types of pouch batteries.

[0046] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the first breathable liquid-resistant membrane 43 and the elastic member 42 are arranged sequentially from the inside to the outside along the extension direction of the air guide channel; the exhaust assembly 4 also includes a limiting member 44, which is disposed in the air guide channel and connected to the main valve body 41.

[0047] Along the extension direction of the air guide channel, the limiting member 44 is disposed on the side of the first air-permeable liquid-blocking membrane 43 away from the outer covering membrane 2. When the soft-pack battery does not vent, the first air-permeable liquid-blocking membrane 43 abuts against the limiting member 44. The limiting member 44 is used to limit the first air-permeable liquid-blocking membrane 43 and to make the elastic member 42 in a compressed state.

[0048] As can be seen from the structure described above, a limiting member 44 is provided on one side of the first gas-permeable liquid-blocking membrane 43, thereby limiting the first gas-permeable liquid-blocking membrane 43 and preventing the first gas-permeable liquid-blocking membrane 43 from overstretching the elastic member 42, which would affect normal use. In particular, when the soft-pack battery is placed horizontally, under the action of gravity, if there is no limiting member 44 below to limit the first gas-permeable liquid-blocking membrane 43, the elastic member 42 will be overstretched, and the first gas-permeable liquid-blocking membrane 43 may slide out from the bottom of the air channel.

[0049] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the exhaust assembly 4 also includes a second permeable liquid-blocking membrane 45, which is disposed in the air guide channel. The first permeable liquid-blocking membrane 43, the elastic member 42, and the second permeable liquid-blocking membrane 45 are arranged sequentially from the inside to the outside along the extension direction of the air guide channel and are connected to each other. The second permeable liquid-blocking membrane 45 is connected to the main valve body 41, and the porosity of the second permeable liquid-blocking membrane 45 is greater than that of the first permeable liquid-blocking membrane 43. That is, the diameter of the second permeable liquid-blocking membrane 45 is greater than that of the first permeable liquid-blocking membrane 43.

[0050] As can be seen from the structure described above, a second gas-permeable liquid-blocking membrane 45 is provided on the basis of the first gas-permeable liquid-blocking membrane 43, and the diameter of the second gas-permeable liquid-blocking membrane 45 is larger than the diameter of the first gas-permeable liquid-blocking membrane 43. So when the first gas-permeable liquid-blocking membrane 43 is opened, the second gas-permeable liquid-blocking membrane 45 can both ensure normal venting and block electrolyte, thus preventing leakage.

[0051] Furthermore, preferably, the inner wall of the air guiding channel is formed with a limiting surface perpendicular to its extension direction, and the second air-permeable liquid-blocking membrane 45 is fixed on this limiting surface, for example, by means of adhesive.

[0052] It should be noted that the structure is not limited to the above-mentioned simultaneous setting of two gas-permeable liquid-blocking membranes, namely the first gas-permeable liquid-blocking membrane 43 and the second gas-permeable liquid-blocking membrane 45. Other structures can also be used. For example, only the first gas-permeable liquid-blocking membrane 43 can be set. When no gas is being released, the first gas-permeable liquid-blocking membrane 43 blocks the gas guiding channel. When gas is being released, the first gas-permeable liquid-blocking membrane 43 is pushed open by the gas, thereby opening the gas guiding channel. It should be noted here that in the prior art, the electrolyte inside the outer film 2 of the soft-pack battery is completely immersed in the electrode sheet, and there are almost no free bodies. Therefore, during the opening of the first gas-permeable liquid-blocking membrane 43, the problem of large-area leakage 311 will not occur. Therefore, only the first gas-permeable liquid-blocking membrane 43 can be set. In this embodiment, the first gas-permeable liquid-blocking membrane 43 and the second gas-permeable liquid-blocking membrane 45 are set at the same time, which plays a double insurance role and the structure is more reliable. However, both structures can achieve gas venting and meet the usage requirements.

[0053] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the second air-permeable and liquid-blocking membrane 45 is a liquid-repellent microporous membrane, which can both allow air to pass through and block electrolyte, thus meeting the usage requirements.

[0054] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the diameter of the pores in the second gas-permeable and liquid-blocking membrane 45 is d2 (d2 is not shown in the figure), and 0.1um ≤ d2 ≤ 1um. This makes the pore size of the second gas-permeable and liquid-blocking membrane 45 much smaller than the droplet size of the electrolyte, thereby achieving the functions of gas permeability and liquid blocking. Of course, the value of d2 is not limited to the above-mentioned preferred value; d2 can also be set to < 0.1um or > 1um.

[0055] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the thickness of the second gas-permeable liquid-blocking membrane 45 is t2 (not shown in the figure), and 10um≤t2≤100um.

[0056] Based on the structure described above, it is clear that if the thickness of the second breathable liquid-blocking membrane 45 is too large, the required air pressure to open it will be too high, making it difficult to expel air. If the thickness of the second breathable liquid-blocking membrane 45 is too small, its strength will be low, affecting its service life. Therefore, the thickness t2 of the second breathable liquid-blocking membrane 45 is selected within the range of 10um-100um. Of course, the value of t2 is not limited to the above-mentioned optimal value; t2 can also be set to <10um or >100um.

[0057] In this embodiment, preferably, as follows: Figure 2 and Figure 3 As shown, a portion of the main valve body 41 and the air guide hole 4142 thereon are disposed outside the gas collection area 31, and another portion of the main valve body 41 is disposed inside the gas collection area 31. The elastic member 42 and the first air-permeable liquid-resistant membrane 43 are both disposed within the structure of the main valve body 41 located inside the gas collection area 31.

[0058] As can be seen from the structure described above, a part of the main valve body 41 is located inside the gas collection area 31, that is, inside the air bag, and a part of the main valve body 41 is located outside the gas collection area 31, that is, outside the air bag. This makes the main valve body 41 and the outer membrane 2 more firmly and stably assembled, and facilitates exhaust.

[0059] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the main valve body 41 includes an air guide pipe 411, a mounting base 412, a valve seat 414, and a protective cover 415; wherein, the air guide pipe 411 and the mounting base 412 are both disposed inside the air collection area 31, and the air guide pipe 411 is connected to the mounting base 412, and the mounting base 412 is disposed relative to the air guide pipe 411 and close to the outer membrane 2;

[0060] The air guiding channel is formed on the air guiding pipe 411, the mounting base 412 and the valve seat 414. That is, along the extension direction of the air guiding channel, the air guiding component has a first air guiding channel 4111 that runs through both sides, the mounting base 412 has a second air guiding channel 4121 that runs through both sides, and the valve seat 414 has a third air guiding channel 4141 that runs through both sides. The first air guiding channel 4111, the second air guiding channel 4121 and the third air guiding channel 4141 together form the air guiding channel.

[0061] The first breathable liquid-resistant membrane 43 and the elastic member 42 are both disposed in the air guide channel, i.e. the second air guide channel 4121, within the mounting base 412; the mounting base 412 has a mounting protrusion ring 413 extending to the outside of the gas collection area 31, and the valve seat 414 is connected to the mounting protrusion ring 413. The mounting protrusion ring 413 serves to install and support the valve seat 414. Moreover, after both are installed, the valve seat 414 and the mounting base 412 are respectively sandwiched on the inner and outer sides of the outer membrane 2, so that the exhaust assembly 4 can be firmly fixed on the outer membrane 2.

[0062] The protective cover 415 is sealed at the opening end of the air passage of the valve seat 414, and the protective cover 415 serves to prevent dust. The air passage 4142 is formed on the side wall of the valve body and is used to discharge the gas inside the outer membrane 2 to the outside of the outer membrane 2, that is, the outside of the soft pack battery.

[0063] As can be seen from the structure described above, the main valve body 41 is designed as a split structure, which facilitates the assembly with the outer membrane 2 and the assembly of internal structural components such as the two breathable liquid-resistant membranes and the elastic component 42, thereby improving the ease of operation.

[0064] Further, preferably, such as Figure 1 and Figure 3 As shown, the main valve body 41 also includes a gasket 46, which is fitted over the mounting protrusion ring 413 and pressed between the valve body and the mounting seat 412. It is evident that the gasket 46 serves to distribute pressure, prevent loosening, and seal against leakage.

[0065] It should be noted that: it is not limited to designing the main valve body 41 as a split structure as described above, which can be assembled together later. Alternatively, the valve body can be designed as an integral structure, that is, the main valve body 41 can be set as a single component, etc., depending on the actual needs.

[0066] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the air guide pipe 411 is an arc-shaped bend.

[0067] As can be seen from the structure described above, the air guide pipe 411 adopts an arc-shaped bend to avoid the electrolyte directly impacting the first permeable liquid barrier membrane 43 during the exhaust process.

[0068] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the open end of the arc-shaped bend away from the mounting base 412 is positioned towards the electrode assembly 1, which makes it easier to exhaust the gas from one side of the electrode assembly 1. Of course, it is not limited to this, and can also be designed according to actual needs, such as the open end of the arc-shaped bend away from the mounting base 412 being positioned away from the electrode assembly 1.

[0069] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the curvature of the curved pipe is α (not shown in the figure), and 30°≤α≤60°, which meets the usage requirements.

[0070] Furthermore, preferably, the arc angle α of the curved bend is 45°.

[0071] In this embodiment, preferably, as follows: Figure 1 and Figure 3As shown, the valve seat 414 and the mounting protrusion ring 413 are detachably connected by threads, which is a detachable connection structure that facilitates installation and disassembly, especially for later maintenance. Connecting the valve seat 414 and the mounting protrusion ring 413 can be completed simply by rotating the valve seat 414, saving time and effort, and ultimately causing the valve seat 414 to press against the washer 46. Of course, the valve seat 414 and the mounting protrusion can also be connected by interference fit, snap-fit, bolts, or welding, depending on the specific needs.

[0072] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the protective cover 415 and the valve seat 414 are connected by adhesive, which is simple, convenient and low cost. Of course, it is not limited to this. The protective cover 415 and the valve seat 414 can also be connected by snap-fit, bolt, welding or heat fusion, etc., depending on the actual needs.

[0073] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the first air-permeable and liquid-blocking membrane 43 is a liquid-repellent microporous membrane, which can both allow air to pass through and block electrolyte, thus meeting the usage requirements.

[0074] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the diameter of the pores in the first gas-permeable and liquid-blocking membrane 43 is d1 (d1 is not shown in the figure), and 0.1um ≤ d1 ≤ 1um, which makes the pores of the first gas-permeable and liquid-blocking membrane 43 much smaller than the droplet size of the electrolyte, thereby achieving the functions of gas permeability and liquid blocking. Of course, the value of d1 is not limited to the above-mentioned preferred value; d1 can also be set to < 0.1um or > 1um.

[0075] In this embodiment, preferably, as follows: Figure 1 and Figure 3 As shown, the thickness of the first gas-permeable liquid-blocking membrane 43 is t1 (not shown in the figure), and 10um≤t1≤100um.

[0076] Based on the structure described above, it is clear that if the thickness of the first breathable liquid-resistant membrane 43 is too large, the required air pressure to open it will be too high, making it difficult to expel air. If the thickness of the first breathable liquid-resistant membrane 43 is too small, its strength will be low, affecting its service life. Therefore, the thickness t1 of the first breathable liquid-resistant membrane 43 is selected within the range of 10um-100um. Of course, the value of t1 is not limited to the above-mentioned optimal value; t1 can also be set to <10um or >100um.

[0077] In this embodiment, preferably, as follows: Figure 2As shown, along the length direction b of the electrode assembly, one end of the electrode assembly 1 has a tab 11, i.e., a positive tab and a negative tab (of course, it is not limited to this; tabs 11 can also be formed at both ends of the electrode assembly 1 along the length direction b of the electrode assembly, depending on actual needs). Along the width direction a of the electrode assembly, a gas collection area 31 is provided on one side of the electrode assembly 1, for example, the left side (of course, it is not limited to this; a gas collection area 31 can also be provided on the right side of the electrode assembly 1), to meet the exhaust requirements. Of course, it is not limited to this; other structures can also be used. For example, gas collection areas 31 can be provided on both opposite sides of the electrode assembly 1 along the width direction a of the electrode assembly, or a gas collection area 31 can be provided on the side of the electrode assembly 1 where no tabs are formed, etc.

[0078] In addition, it should be noted that the number of exhaust components 4 on the gas collection area 31 is one in this embodiment. Of course, it is not limited to this and can be multiple, etc., depending on the actual needs.

[0079] In this embodiment, preferably, as follows: Figure 2 and Figure 3 As shown, the exhaust assembly 4 is installed on the large surface 311 of the gas collection area 31, and the exhaust assembly 4 is set along the thickness direction c of the soft-pack battery, making full use of the space on the side of the large surface 311 to facilitate the installation of the exhaust assembly 4. Of course, it is not limited to installing the exhaust assembly 4 on the large surface 311 of the gas collection area 31; it can also be installed in other areas, depending on actual needs. In addition, it should be noted that the thickness direction c of the soft-pack battery is the same as the thickness direction of the electrode assembly 1.

[0080] Furthermore, when the pouch battery is placed horizontally, the venting assembly 4 is installed on the large surface 311 at the top of the gas collection area 31, and the first gas-permeable liquid-resistant membrane 43 is positioned below the elastic member 42. This allows full utilization of the weight of the first gas-permeable liquid-resistant membrane 43 and the elastic force of the elastic member 42 to achieve the repositioning of the first gas-permeable liquid-resistant membrane 43. It should be noted that the pouch battery can be placed not only horizontally but also according to the actual required orientation.

[0081] It should be noted that the aforementioned large surface 311 refers to the surface formed by the long side and the wide side of the soft-pack battery.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A pouch battery, characterized by, include: An electrode assembly, an outer coating, and an exhaust assembly are provided. The outer coating covers the outside of the electrode assembly, and a gas collection area is formed on the side of the outer coating of the electrode assembly where no tabs are formed. This gas collection area is used to collect the gas generated by the electrode assembly. The exhaust assembly is installed in the gas collection area and is used to discharge the gas collected inside the gas collection area. The exhaust assembly includes a main valve body, an elastic member, and a first gas-permeable liquid-resistant membrane. The main valve body is installed in the gas collection area and has a gas guide channel and a gas guide hole. The gas guide channel communicates with the interior of the gas collection area, and the gas guide channel communicates with the exterior of the gas collection area through the gas guide hole. The first gas-permeable liquid-resistant membrane and the elastic member are sequentially disposed within the gas-guiding channel along the extension direction of the gas-guiding channel. The first gas-permeable liquid-resistant membrane is connected to the main valve body through the elastic member. When the soft-pack battery does not vent, the first gas-permeable liquid-resistant membrane blocks the gas-guiding channel. When the soft-pack battery vents, the first gas-permeable liquid-resistant membrane is pushed open by the gas to open the gas-guiding channel for venting. The elastic member is used to reset the first gas-permeable liquid-resistant membrane to block the gas-guiding channel again. 2.The pouch battery of claim 1, wherein, The first breathable liquid-resistant membrane and the elastic member are arranged sequentially from the inside to the outside along the extension direction of the air guide channel; the exhaust assembly also includes a limiting member, which is disposed in the air guide channel and connected to the main valve body; Along the extension direction of the air-conducting channel, the limiting member is disposed on the side of the first air-permeable liquid-resistant membrane away from the outer covering film, and when the soft-pack battery is not venting, the first air-permeable liquid-resistant membrane abuts against the limiting member, the limiting member is used to limit the first air-permeable liquid-resistant membrane, and causes the elastic member to be in a compressed state. 3.The pouch battery of claim 2, wherein, The exhaust assembly further includes a second gas-permeable liquid-blocking membrane, which is disposed within the air-guiding channel. The first gas-permeable liquid-blocking membrane, the elastic member, and the second gas-permeable liquid-blocking membrane are sequentially arranged and connected from the inside to the outside along the extension direction of the air-guiding channel. The second gas-permeable liquid-blocking membrane is connected to the main valve body, and the porosity of the second gas-permeable liquid-blocking membrane is greater than that of the first gas-permeable liquid-blocking membrane.

4. The soft-pack battery according to claim 3, characterized in that, The second gas-permeable liquid-blocking membrane is a liquid-phobic microporous membrane; and / or The diameter of the pores in the second gas-permeable liquid-blocking membrane is d2, and 0.1µm ≤ d2 ≤ 1µm; and / or The thickness of the second air-permeable liquid-blocking membrane is t2, and 10um≤t2≤100um.

5. The soft-pack battery according to claim 1, characterized in that, A portion of the main valve body and the air guide hole thereon are disposed outside the gas collection area, and another portion of the main valve body is disposed inside the gas collection area. The elastic member and the first air-permeable liquid-resistant membrane are both disposed within the structure of the main valve body located inside the gas collection area.

6. The soft-pack battery according to claim 5, characterized in that, The main valve body includes an air guide pipe, a mounting base, a valve seat, and a protective cover; wherein, the air guide pipe and the mounting base are both disposed inside the gas collection area, and the air guide pipe is connected to the mounting base, and the mounting base is disposed relative to the air guide pipe and close to the outer membrane; The air guide channel is formed on the air guide pipe, the mounting base, and the valve seat, and the first gas-permeable liquid-resistant membrane and the elastic member are both disposed in the air guide channel within the mounting base; the mounting base has a mounting protrusion ring extending to the outside of the gas collection area, and the valve seat is connected to the mounting protrusion ring; the protective cover seals the opening end of the air guide channel of the valve seat; the air guide hole is formed on the side wall of the valve body.

7. The soft-pack battery according to claim 6, characterized in that, The air guide pipe is an arc-shaped bend.

8. The soft-pack battery according to claim 7, characterized in that, The open end of the arc-shaped bend, away from the mounting base, is positioned towards the electrode assembly; and / or The arc of the curved pipe is α, and 30°≤α≤60°.

9. The soft-pack battery according to claim 6, characterized in that, The valve seat is detachably threaded to the mounting protrusion ring; and / or The protective cover is connected to the valve seat by adhesive bonding; and / or The main valve body also includes a gasket, which is sleeved on the outside of the mounting protrusion ring and pressed between the valve body and the mounting base.

10. The pouch cell battery according to any one of claims 1 to 9, characterized in that, The first gas-permeable liquid-resistant membrane is a liquid-phobic microporous membrane; and / or The diameter of the pores in the first gas-permeable liquid-resistant membrane is d1, and 0.1µm ≤ d1 ≤ 1µm; and / or The thickness of the first gas-permeable liquid-resistant membrane is t1, and 10µm ≤ t1 ≤ 100µm; and / or Along the length direction of the electrode assembly, at least one end of the electrode assembly has the tab formed thereon; along the width direction of the electrode assembly, one side of the electrode assembly has the gas collection area; and / or The main valve body is installed on the large surface of the gas collection area, and the main valve body is arranged along the thickness direction of the soft-pack battery. When the soft-pack battery is placed horizontally, the main valve body is installed on the large surface at the top of the gas collection area, and the first gas-permeable liquid-resistant membrane is disposed below the elastic member.

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