High-safety soft package battery and preparation method thereof

Abstract

The application discloses a high-safety soft package battery and a preparation method thereof. The high-safety soft package battery comprises a battery core and a soft package bag. A partition strip is arranged in the soft package bag, and the soft package bag is divided into a battery bag and an inhibitor bag by the partition strip. The battery core is arranged in the battery bag. The inhibitor bag is filled with a thermal runaway inhibitor. A weak point is arranged on the partition strip, and the weak point can form a channel to connect the battery bag and the inhibitor bag under a preset temperature and a preset pressure. The high-safety soft package battery connects the battery bag with the battery core and the inhibitor bag filled with the inhibitor through the partition strip with the weak point. When the high-safety soft package battery is self-heated or swells, the battery bag and the inhibitor bag are connected, the further electrochemical reaction is blocked through the inhibitor, and the thermal runaway of the battery is inhibited.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a high-safety soft package battery and a preparation method thereof. BACKGROUND

[0002] As a kind of energy storage device, batteries are increasingly widely used in the fields of electric vehicles and energy storage with the promotion of the national new energy strategy. The soft package battery occupies an increasing share in the market of three structural types of batteries, i.e. cylindrical, square and soft package, due to its advantages of flexible size, light weight, thin thickness and easy mass production. Many battery companies are actively laying out high-safety soft package battery production lines. However, the application of high-safety soft package batteries is subject to certain restrictions due to their safety protection defects such as lack of explosion-proof measures and poor protection.

[0003] The thermal runaway suppression technology of high-safety soft package batteries in the industry still adopts the scheme of cylindrical or square batteries, which passively suppresses the thermal runaway of the battery by thermal resistance and by detecting and triggering the spraying of fire extinguishing agents. This method mainly passively suppresses and extinguishes the battery when it has already occurred thermal runaway, smoke or open fire, or even deflagration spread. The suppression effect is poor. SUMMARY

[0004] (I) Invention purpose

[0005] The present application provides a high-safety soft package battery and a preparation method thereof. The high-safety soft package battery connects a battery pouch with an electric core and an inhibitor pouch filled with an inhibitor through a separation strip with a weak point. When the high-safety soft package battery spontaneously heats or swells, the battery pouch and the inhibitor pouch are connected, the further electrical reaction is blocked by the inhibitor, and the thermal runaway of the battery is suppressed.

[0006] (II) Technical solution

[0007] The first aspect of the present application provides a high-safety soft package battery, comprising an electric core and a soft package bag.

[0008] The soft package bag is provided with a separation strip, which divides the soft package bag into a battery pouch and an inhibitor pouch.

[0009] The electric core is arranged in the battery pouch.

[0010] The inhibitor pouch is filled with a thermal runaway inhibitor.

[0011] The separation strip is provided with a weak point. When the temperature of the weak point exceeds a preset temperature and the pressure exceeds a preset pressure, a channel is formed to connect the battery pouch and the inhibitor pouch.

[0012] In some embodiments, when the battery pouch and the inhibitor pouch are in communication, the thermal runaway inhibitor is used to mix with the electrolyte in the battery pouch to block the electrochemical reaction in the battery pouch.

[0013] In some embodiments, when the battery pouch and the inhibitor pouch are in communication, the thermal runaway inhibitor is used to mix with the electrolyte in the battery pouch and vaporize to reduce the temperature in the battery pouch.

[0014] In some embodiments, the thermal runaway inhibitor is one or more of the following: perfluoroalkene, perfluoroether, hydrofluoroether, silicone oil, transformer oil, fluorine-containing organic compound, insulating oil.

[0015] In some embodiments, the separation strip is hot-pressed from a double-layered aluminum-plastic film, and a weak point is provided between the double-layered aluminum-plastic film.

[0016] In some embodiments, the weak point is opened when the temperature and pressure exceed the preset temperature and pressure, respectively.

[0017] The second aspect of the present application provides a method for preparing a high-safety soft-pack battery, comprising:

[0018] coating the battery cell with a soft-pack film;

[0019] performing primary packaging on the soft-pack film to form a soft-pack bag having one open end;

[0020] injecting electrolyte into the soft-pack bag through the opening;

[0021] performing secondary packaging on the open end of the soft-pack bag to form a separation strip, the separation strip divides the soft-pack bag into a battery pouch and an inhibitor pouch, and the battery cell is arranged in the battery pouch;

[0022] injecting a thermal runaway inhibitor into the inhibitor pouch and sealing the inhibitor pouch.

[0023] In some embodiments, before performing the secondary packaging on the soft-pack bag, a weak point is designed on the separation strip of the soft-pack bag.

[0024] In some embodiments, when performing the secondary packaging on the soft-pack bag, hot melt adhesive is locally filled between the double-layered aluminum-plastic film to form the weak point.

[0025] In some embodiments, when performing the secondary packaging on the soft-pack bag, the width of the hot-pressed double-layered aluminum-plastic film seal is locally reduced to form the weak point when the separation strip is formed.

[0026] (Three) beneficial effects

[0027] The above technical solutions of the present application have the following beneficial technical effects:

[0028] The high-safety soft package battery provided by the embodiment of the present application connects the battery bag with the inhibitor bag filled with inhibitors through the partition strip with the weak point, and when the high-safety soft package battery enters failure, the battery bag and the inhibitor bag are connected by using the characteristics of the battery self-heating or the internal pressure increase of the battery inflation, so that the inhibitors enter the battery body, the further electrical reaction in the battery is blocked by the inhibitors, or the further electrical reaction is inhibited and heat is absorbed at the same time, the battery thermal runaway is actively inhibited from the battery itself, and then the problem of flammability and explosiveness of the battery is solved, and the high safety and high protection performance of the soft package battery are realized. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structure diagram of the high-safety soft package battery provided by the first embodiment of the present application;

[0030] Figure 2 is a structure diagram of the high-safety soft package battery provided by the second embodiment of the present application;

[0031] Figure 3 is a structure diagram of the high-safety soft package battery provided by the third embodiment of the present application;

[0032] Figure 4 is a structure diagram of the high-safety soft package battery provided by the fourth embodiment of the present application;

[0033] Figure 5 is a structure diagram of the high-safety soft package battery provided by the fifth embodiment of the present application;

[0034] Figure 6 is a flow chart of the preparation method of the high-safety soft package battery provided by an embodiment of the present application.

[0035] In the drawings,

[0036] Positive electrode tab, 11; negative electrode tab, 12;

[0037] Soft package bag, 2; battery bag, 21; inhibitor bag, 22; partition strip, 23; weak point, 231; main weak point, 2311; secondary weak point, 2312; battery bag sealing edge, 24; inhibitor bag sealing edge, 25. DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the specific embodiments and drawings. It should be understood that the description is only exemplary, but not to limit the scope of the present application. In addition, in the following description, the description of the well-known structures and techniques is omitted to avoid unnecessary confusion of the concept of the present application.

[0039] In the description of the present application, it should be noted that the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0040] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict between them.

[0041] Figure 1 is a structural schematic diagram of a high-safety soft-pack battery provided by the first embodiment of the present application.

[0042] As Figure 1As shown, the first embodiment of the present application provides a high-safety soft package battery. The high-safety soft package battery in this embodiment is a lithium battery, and is also applicable to other ion batteries that rely on internal ion migration to achieve electrochemical energy storage functions, such as sodium ion batteries and aluminum ion batteries, etc. The high-safety soft package battery comprises a battery cell and a soft package bag 2. In this embodiment, the soft package bag 2 is made of an aluminum plastic film, and the melting point of the aluminum plastic film is between 180°C and 220°C. The soft package bag 2 is provided with a partition strip 23, and the partition strip 23 divides the soft package bag 2 into a battery capsule bag 21 and an inhibitor capsule bag 22. The partition strip 23 is provided with a weak point 231, and when the temperature of the weak point 231 exceeds a preset temperature and the pressure exceeds a preset pressure, a channel is formed to connect the battery capsule bag 21 and the inhibitor capsule bag 22. In this embodiment, the partition strip 23 is made of double-layer aluminum plastic film, and hot melt glue is arranged between the double-layer aluminum plastic film to form the weak point 231. The volume and size of the inhibitor capsule bag can be adjusted according to the effect of the inhibitor. The volume of the inhibitor capsule bag with multiple inhibition effects needs to be smaller than the volume of the battery capsule bag, and the volume of the inhibitor capsule bag with single and less inhibition effects needs to be larger than the volume of the battery capsule bag. When the inhibitor is a fluorine-containing compound, the volume of the inhibitor capsule bag 22 is less than or equal to the volume of the battery capsule bag 21. When the inhibitor is insulating oil, the volume of the inhibitor capsule bag 22 is greater than the volume of the battery capsule bag 21. The inhibitor can fill the inhibitor capsule bag 22. In this embodiment, the length of the weak point 231 is one-tenth of the length of the partition strip 23, and the number of the weak point 231 is two. The two weak points 231 are respectively arranged at both ends of the partition strip 23. In some embodiments, the weak point 231 can be formed by reducing the local width of the partition strip 23. In this embodiment, the hot melt glue is added between the double-layer aluminum plastic film to form the weak point 231. When the temperature of the weak point 231 exceeds the preset temperature and the pressure exceeds the preset pressure, the hot melt glue peels off to form a channel. The thickness of the hot melt glue is 0.08 mm. The melting point of the hot melt glue is greater than 70°C and less than 220°C. In this embodiment, the hot melt glue is black tab glue, which is composed of polypropylene PE with a melting point of 103°C and polyethylene PP with a melting point of 137°C. The melting point of the hot melt glue can be 130°C. The viscosity of the hot melt glue gradually decreases with the increase of temperature, and the weak point 231 forms a channel when it simultaneously meets the preset temperature and the preset pressure. The greater the preset temperature, the smaller the preset pressure. The preset temperature and the preset pressure can be 90°C and 0.8 MPa, respectively. The preset temperature and the preset pressure can also be 100°C and 0.6 MPa, respectively. The preset temperature and the preset pressure can also be 110°C and 0.4 MPa, respectively. The preset temperature and the preset pressure can also be 0°C and 1 MPa, respectively. The preset temperature and the preset pressure can also be 130°C and 0 MPa, respectively. The battery cell is arranged in the battery capsule bag 21. In this embodiment, the battery cell comprises a positive tab 11 and a negative tab 12, and the battery capsule bag 21 is filled with an electrolyte to form a battery body.In this embodiment, the positive tab 11 is arranged on the top surface of the battery pouch 21, the negative tab 12 is arranged on the bottom surface of the battery pouch 21, the separator strip 23 is arranged on the right side surface of the battery pouch 21, and the left side surface of the battery pouch 21 further comprises a battery pouch sealing edge 24. The inhibitor pouch 22 is filled with a thermal runaway inhibitor. The thermal runaway inhibitor can be a fluorine-containing organic compound. The fluorine-containing organic compound has stable chemical properties and is easy to volatilize. Even if it is pierced by external force, it will not react with the battery and the PACK assembly materials at ambient temperature. It belongs to environmentally friendly and design-friendly materials. When the temperature exceeds the preset temperature and the pressure exceeds the preset pressure, the battery pouch 21 and the inhibitor pouch 22 are communicated, the inhibitor enters the battery body, mixes with the electrolyte, blocks the ion movement channel in the electrolyte, blocks the electrochemical reaction, and phase change heat absorption reduces the temperature of the high-safety soft package battery, thereby achieving the effect of actively inhibiting the thermal runaway of the battery. This mechanism is applicable to ion batteries that achieve electrochemical energy storage function through ion migration, such as lithium ion batteries, sodium ion batteries, aluminum ion batteries, etc. When the battery pouch 21 and the inhibitor pouch 22 are communicated, the thermal runaway inhibitor is used to mix with the electrolyte in the battery pouch and vaporize to reduce the temperature in the battery pouch. The thermal runaway inhibitor can be selected from one or more of the following: perfluoroalkene, perfluoroether, hydrofluoroether, silicone oil, transformer oil. The boiling point of the thermal runaway inhibitor can be selected to be less than 30°C from the critical temperature of the battery SEI film decomposition. The boiling point of the thermal runaway inhibitor can be selected to be greater than 70°C and less than 90°C. The boiling point of the thermal runaway inhibitor can be selected to be 76°C. The boiling point of the thermal runaway inhibitor can be selected to be less than 30°C from the critical temperature of the battery electrolyte decomposition. The boiling point of the thermal runaway inhibitor can be selected to be greater than 90°C and less than 140°C. The boiling point of the thermal runaway inhibitor can be selected to be 131°C. As shown in the figure. Figure 1 As shown in the figure, the width of the battery pouch 21 is W and the length is L. W can be 30mm, W can also be 40mm, W can also be 50mm, L can be 50mm, L can also be 70mm, and L can also be 100mm. The width of the inhibitor pouch 22 is x and the length is y, wherein x is greater than or equal to 10mm and less than or equal to L, and y is greater than or equal to 1mm and less than or equal to W. In this embodiment, the length of the weak point 231 is 1mm. The number and size of the inhibitor pouch 22 can be designed according to actual needs.

[0043] The high-safety soft package battery is divided into three stages according to the battery thermal runaway stage division theory: T1 spontaneous heating stage (50 DEG C-140 DEG C), T2 thermal runaway stage (140 DEG C-850 DEG C), and T3 thermal runaway termination stage (850 DEG C-normal temperature). In the T1 spontaneous heating stage, the high-safety soft package battery is accompanied by decomposition of SEI film (solid electrolyte interface film), electrolyte and the like, gradually produces gas expansion, the pressure in the battery bag 21 increases, when the pressure in the battery bag 21 reaches the preset pressure, the weak point 231 first forms a break, the battery bag 21 and the inhibitor bag 22 are communicated, the fluorine-containing organic compound in the inhibitor bag 22 is immersed into the battery bag 21, the first aspect utilizes the stability of the fluorine-containing organic compound to block the lithium ion from continuing to transfer, and the second aspect utilizes the physical property of the fluorine-containing organic compound vaporization heat absorption to absorb the heat inside the high-safety soft package battery, thereby directly reducing the temperature of the high-safety soft package battery. Compared with the method of related art, after thermal runaway occurs, a series of sensors such as flame and gas are passively used to detect and trigger conventional extinguishing agent such as superfine dry powder to extinguish the lithium ion battery fire, the high-safety soft package battery provided in the embodiment can intervene in inhibition in the early stage of thermal runaway, and the safety problem of the high-safety soft package battery without explosion-proof measures can be solved earlier, more effectively and more directly.

[0044] Figure 2 is a structural schematic diagram of the high-safety soft package battery provided in the second embodiment of the application. Figure 2As shown, the second embodiment of the present application provides a high-safety soft-pack battery, which comprises a battery cell and a soft pack 2. The soft pack 2 is provided with a partition strip 23, which divides the soft pack 2 into a battery pouch 21 and an inhibitor pouch 22. The partition strip 23 is provided with a weak point 231, which can form a channel to connect the battery pouch 21 and the inhibitor pouch 22 at a preset temperature and a preset pressure. In this embodiment, the battery cell comprises a positive electrode tab 11 and a negative electrode tab 12, and the battery pouch 21 is filled with electrolyte to form a battery body. In this embodiment, the positive electrode tab 11 and the negative electrode tab 12 are arranged at intervals on the top surface of the battery pouch 21, and the partition strip 23 is arranged on the right side surface of the battery pouch 21. The left side surface of the battery pouch 21 further comprises a battery pouch edge 24. In this embodiment, the number of inhibitor pouches 22 is multiple, which can be 2, 3, or 4. Adjacent inhibitor pouches 22 can be spaced apart by 1 mm or 2 mm. The multiple inhibitor pouches 22 are arranged at intervals on the right side surface of the battery pouch 21. The width x of the inhibitor pouch 22 can be one-fifth of the width W of the battery pouch 21, or one-fourth of the width W of the battery pouch 21. The length y of the inhibitor pouch 22 can be one-fifth of the length L of the battery pouch 21, or one-fourth of the length L of the battery pouch 21.

[0045] In some embodiments, the weak points 231 include main weak points 2311 and secondary weak points 2312, and the battery cell includes a positive electrode tab 11 and a negative electrode tab 12. The sum of the distances from the main weak points 2311 to the positive electrode tab 11 and the negative electrode tab 12 is greater than the sum of the distances from the secondary weak points 2312 to the positive electrode tab 11 and the negative electrode tab 12. For example, the distance from the main weak point 2311 to the positive electrode tab 11 is L1, the distance from the main weak point 2311 to the negative electrode tab 12 is L2, the distance from the secondary weak point 2312 to the positive electrode tab 11 is L3, and the distance from the secondary weak point 2312 to the negative electrode tab 12 is L4. The sum of L1 and L2 is greater than the sum of L3 and L4. The number of main weak points 2311 is one or more. The main weak points 2311 can be arranged at the points on the separation strip 23 that have the greatest sum of distances to the positive electrode tab 11 and the negative electrode tab 12. The number of secondary weak points 2312 is one or more. The secondary weak points 2312 can be arranged at the points on the separation strip 23 that have the smallest sum of distances to the positive electrode tab 11 and the negative electrode tab 12. When the high-safety soft package battery fails and swells, the position on the soft package bag 2 that has the greatest sum of distances to the positive electrode tab 11 and the negative electrode tab 12 is likely to swell first, and the area that swells first is likely to form a local high-pressure area. The positions close to the positive electrode tab 11 and the negative electrode tab 12 are not likely to deform and are likely to form a low-pressure area. When the high-safety soft package battery fails and swells, the main weak points 2311 of the high-pressure area first form a channel, the battery capsule bag 21 discharges high-temperature gas to the inhibitor capsule bag 22 through the channel formed by the main weak points 2311, the inhibitor in the inhibitor capsule bag 22 is squeezed by the high-temperature gas, the secondary weak points 2312 are squeezed to form a channel, the inhibitor enters the battery capsule bag 21 through the channel formed by the secondary weak points 2312, the inhibitor mixes with the electrolyte in the battery capsule bag 21 to block the electrochemical reaction, and the temperature in the battery capsule bag 21 is reduced, thereby achieving the effect of actively inhibiting thermal runaway of the high-safety soft package battery.

[0046] Figure 3 is a structural schematic diagram of a high-safety soft package battery provided by a third embodiment of the present application. As shown in Figure 3As shown, the third embodiment of the present application provides a high safety soft package battery, which comprises a battery cell and a soft package bag 2. The soft package bag 2 is provided with a partition strip 23, which divides the soft package bag 2 into a battery bag 21 and an inhibitor bag 22, and the inhibitor bag 22 is provided with an inhibitor bag sealing edge 25 away from the battery bag. The battery bag 21 is rectangular, and the battery cell comprises a positive electrode tab 11 and a negative electrode tab 12, which are arranged on the top surface of the battery bag 21 in a spaced manner, and the right side of the battery bag 21 is provided with a battery bag sealing edge 24. The partition strip 23 is L-shaped, and comprises a vertical part arranged along the left side of the battery bag 21 and a horizontal part arranged along the bottom surface of the battery bag 21. The partition strip 23 is provided with a weak point 231, and the width of the weak point 231 is smaller than that of other areas. The weak point 231 can form a channel to connect the battery bag 21 and the inhibitor bag 22 at a preset temperature and a preset pressure. The weak point 231 comprises a main weak point 2311 and a secondary weak point 2312. The number of the main weak point 2311 is one, which is arranged at the center of the horizontal part. When the temperature and the pressure of the main weak point 2311 exceed the preset temperature and the preset pressure, the main weak point 2311 can form a channel to connect the battery bag 21 and the inhibitor bag 22, and the diameter of the channel formed by the main weak point 2311 gradually decreases in the direction away from the battery bag 21. The number of the secondary weak point 2312 is two, which is arranged at one end of the vertical part close to the top surface of the battery bag 21. When the temperature and the pressure of the secondary weak point 2312 exceed the preset temperature and the preset pressure, the secondary weak point 2312 can form a channel to connect the battery bag 21 and the inhibitor bag 22, and the diameter of the channel formed by the secondary weak point 2312 gradually increases in the direction away from the battery bag 21. When the high safety soft package battery expands and fails, the inhibitor flows in the direction of the arrow to achieve the effect of actively inhibiting thermal runaway of the high safety soft package battery. Figure 3

[0047] Figure 4 is a structural schematic diagram of the high safety soft package battery provided by the fourth embodiment of the present application. As shown in the figure, the high safety soft package battery comprises a battery cell and a soft package bag 2. The soft package bag 2 is provided with a partition strip 23, which divides the soft package bag 2 into a battery bag 21 and an inhibitor bag 22, and the inhibitor bag 22 is provided with an inhibitor bag sealing edge 25 away from the battery bag. The battery bag 21 is rectangular, and the battery cell comprises a positive electrode tab 11 and a negative electrode tab 12, which are arranged on the top surface of the battery bag 21 in a spaced manner, and the right side of the battery bag 21 is provided with a battery bag sealing edge 24. The partition strip 23 is L-shaped, and comprises a vertical part arranged along the left side of the battery bag 21 and a horizontal part arranged along the bottom surface of the battery bag 21. The partition strip 23 is provided with a weak point 231, and the width of the weak point 231 is smaller than that of other areas. The weak point 231 can form a channel to connect the battery bag 21 and the inhibitor bag 22 at a preset temperature and a preset pressure. The weak point 231 comprises a main weak point 2311 and a secondary weak point 2312. The number of the main weak point 2311 is one, which is arranged at the center of the horizontal part. When the temperature and the pressure of the main weak point 2311 exceed the preset temperature and the preset pressure, the main weak point 2311 can form a channel to connect the battery bag 21 and the inhibitor bag 22, and the diameter of the channel formed by the main weak point 2311 gradually decreases in the direction away from the battery bag 21. The number of the secondary weak point 2312 is two, which is arranged at one end of the vertical part close to the top surface of the battery bag 21. When the temperature and the pressure of the secondary weak point 2312 exceed the preset temperature and the preset pressure, the secondary weak point 2312 can form a channel to connect the battery bag 21 and the inhibitor bag 22, and the diameter of the channel formed by the secondary weak point 2312 gradually increases in the direction away from the battery bag 21. When the high safety soft package battery expands and fails, the inhibitor flows in the direction of the arrow to achieve the effect of actively inhibiting thermal runaway of the high safety soft package battery. Figure 4 ​As shown, the fourth embodiment of the present invention provides a high-safety pouch battery, including a battery cell and a pouch 2. The pouch 2 has a separator 23 dividing it into a battery pouch 21 and an inhibitor pouch 22. The inhibitor pouch 22 has an inhibitor pouch seal 25 on the side away from the battery pouch. The battery pouch 21 is rectangular, and the battery cell includes a positive electrode tab 11 and a negative electrode tab 12, which are spaced apart on the top surface of the battery pouch 21. The separator 23 is U-shaped, including a first vertical portion along the left side of the battery pouch 21, a second vertical portion along the right side of the battery pouch 21, and a horizontal portion along the bottom surface of the battery pouch 21. The separator 23 has a weak point 231, the width of which is smaller than the width of other areas. Under preset temperature and pressure, the weak point 231 can form a channel to connect the battery pouch 21 and the inhibitor pouch 22. The weak point 231 includes a secondary weak point 2312 and a primary weak point 2311. There is one primary weak point 2311, located at the center of the horizontal section. When the temperature and pressure of the primary weak point 2311 exceed a preset temperature and pressure, a channel is formed connecting the battery pouch 21 and the inhibitor pouch 22. The diameter of the channel formed by the primary weak point 2311 gradually decreases along the direction away from the battery pouch 21. There are two secondary weak points 2312, located at one end of the first vertical section near the top surface of the battery pouch 21 and the other end of the second vertical section near the top surface of the battery pouch 21. When the temperature and pressure of the secondary weak points 2312 exceed a preset temperature and pressure, a channel is formed connecting the battery pouch 21 and the inhibitor pouch 22. The diameter of the channel formed by the secondary weak points 2312 gradually increases along the direction away from the battery pouch 21. When the high-safety soft-pack battery expands and fails, the inhibitor... Figure 4 The arrows in the diagram indicate the direction of flow to actively suppress thermal runaway in high-safety pouch batteries. Figure 5 This is a schematic diagram of the structure of the high-safety soft-pack battery provided in the fifth embodiment of the present invention. Figure 5As shown, the fifth embodiment of the present application provides a high-safety soft package battery, which comprises a battery cell and a soft package bag 2. The soft package bag 2 is provided with a partition strip 23, which divides the soft package bag 2 into a battery capsule bag 21 and an inhibitor capsule bag 22. The inhibitor capsule bag 22 is provided with an inhibitor capsule bag sealing edge 25 away from the side of the battery capsule bag. The battery capsule bag 21 is rectangular, and the battery cell comprises a positive electrode tab 11 and a negative electrode tab 12. The positive electrode tab 11 is arranged on the top surface of the battery capsule bag 21, and the negative electrode tab 12 is arranged on the bottom surface of the battery capsule bag 21. The number of the partition strips 23 is two. The partition strips 23 comprise a first partition strip 23 arranged along the left side of the battery capsule bag 21 and a second partition strip 23 arranged along the right side of the battery capsule bag 21. The partition strips 23 are provided with a weak point 231. The width of the weak point 231 is smaller than that of other regions. The weak point 231 can form a channel to connect the battery capsule bag 21 and the inhibitor capsule bag 22 at a preset temperature and a preset pressure. The weak point 231 comprises a main weak point 2311 and a branch weak point 2312. The number of the main weak points 2311 is two. The two main weak points 2311 are arranged at the centers of the first partition strip 23 and the second partition strip 23, respectively. The main weak points 2311 can form a channel to connect the battery capsule bag 21 and the inhibitor capsule bag 22 when the temperature and the pressure exceed the preset temperature and the preset pressure, respectively. The diameter of the channel formed by the main weak points 2311 gradually decreases in the direction away from the battery capsule bag 21. The number of the branch weak points 2312 is four. The four branch weak points 2312 are arranged at the two ends of the first partition strip 23 and the two ends of the second partition strip 23, respectively. The branch weak points 2312 can form a channel to connect the battery capsule bag 21 and the inhibitor capsule bag 22 when the temperature and the pressure exceed the preset temperature and the preset pressure, respectively. The diameter of the channel formed by the branch weak points 2312 gradually increases in the direction away from the battery capsule bag 21. When the high-safety soft package battery is expanded and fails, the inhibitor flows in the direction of the arrow to achieve the effect of actively inhibiting thermal runaway of the high-safety soft package battery. Figure 5

[0048] Figure 6 is a flow chart of the preparation method of the high-safety soft package battery provided by an embodiment of the present application. As shown in Figure 6 , the embodiment of the present application provides a preparation method of a high-safety soft package battery, which comprises the following steps:

[0049] S101: coating the battery cell with a soft package film. In this embodiment, the battery cell is coated with an aluminum plastic film.

[0050] S102: performing primary packaging on the soft package film to form a soft package bag with one open end. In this embodiment, the aluminum plastic film is folded in half, and primary packaging is performed by hot pressing to seal the top surface, the bottom surface and the left side surface, and the right side surface is reserved as an opening.

[0051] S103: injecting an electrolyte into the soft package bag through the opening end. ​

[0052] S104: The soft bag is secondarily packaged to form a separation strip, the separation strip separates the soft bag into a battery pouch and an inhibitor pouch, and the battery cell is arranged in the battery pouch. In this embodiment, the right side of the soft bag is heat-pressed to form a separation strip to complete the secondary packaging. Optionally, the inhibitor pouch is cleaned with industrial alcohol first, and then the inhibitor pouch is cut to adjust the size of the inhibitor pouch according to actual needs. A process of packaging the inhibitor is added between the high-safety soft-pack battery capacity distribution and the normal-temperature aging stage. The number of inhibitor pouches can be one or more. Before the soft bag is secondarily packaged, hot melt adhesive can be added in the soft bag to form a weak point on the separation strip.

[0053] S104: Injecting a thermal runaway inhibitor into the inhibitor pouch and sealing the inhibitor pouch. In this embodiment, the thermal runaway inhibitor is a fluorine-containing organic compound.

[0054] This embodiment divides the thermal runaway of the high-safety soft-pack battery into three stages according to the theory of battery thermal runaway stage division: T1 spontaneous heating stage (50-140°C), T2 thermal runaway stage (140-850°C), and T3 thermal runaway termination stage (850°C-normal temperature). In the T1 spontaneous heating stage, the high-safety soft-pack battery is accompanied by the decomposition of the SEI film (solid electrolyte interface), electrolyte, and other substances, gradually produces gas and expands, the pressure in the battery pouch increases, and when the pressure in the battery pouch reaches a preset pressure, a weak point forms a breach, connecting the battery pouch and the inhibitor pouch, and the fluorine-containing organic compound in the inhibitor pouch is immersed in the battery pouch. The first aspect utilizes the stability of the fluorine-containing organic compound to block the continuous transmission of lithium ions, and the second aspect utilizes the physical property of the vaporization of the fluorine-containing organic compound to absorb heat, directly reducing the temperature of the high-safety soft-pack battery. Compared with the method of using a series of sensors such as fire and gas to detect and trigger conventional fire extinguishing agents such as ultra-fine dry powder to extinguish lithium ion battery fires after thermal runaway occurs, the high-safety soft-pack battery provided by this embodiment can intervene in inhibition at the early stage of thermal runaway, and more effectively and directly solve the safety problem of the high-safety soft-pack battery without explosion-proof measures.

[0055] It should be understood that the above specific embodiments of the present application are only used for illustrative or explanatory purposes of the principles of the present application, and do not constitute a limitation on the present application. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present application shall be included in the protection scope of the present application. In addition, the appended claims of the present application are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A high-safety pouch battery, characterized by comprising: The soft package bag comprises an electric core and a soft bag; The soft bag is provided with a partition strip, which divides the soft bag into a battery bag and an inhibitor bag; The electric core is arranged in the battery bag; The inhibitor bag is filled with a thermal runaway inhibitor; The partition strip is provided with a weak point, which forms a channel to connect the battery bag and the inhibitor bag when the temperature and pressure of the weak point exceed the preset temperature and pressure; The weak point comprises a main weak point and a secondary weak point; The sum of the distances between the main weak point and the positive and negative electrode tabs is greater than the sum of the distances between the secondary weak point and the positive and negative electrode tabs, so that the main weak point forms the channel before the secondary weak point. 2.The high-safety pouch battery of claim 1, wherein, When the battery bag and the inhibitor bag are connected, the thermal runaway inhibitor is used to mix with the electrolyte in the battery bag to block the electrochemical reaction in the battery bag. 3.The high-safety pouch battery of claim 1, wherein, When the battery bag and the inhibitor bag are connected, the thermal runaway inhibitor is used to mix with the electrolyte in the battery bag and vaporize to reduce the temperature in the battery bag. 4.The high-safety pouch battery of claim 1, wherein, The thermal runaway inhibitor is one or more of the following: perfluoroalkene, perfluoroether, hydrofluoroether, silicone oil, transformer oil, fluorine-containing organic compound, and insulating oil. 5.The high-safety pouch battery of claim 1, wherein, The partition strip is made of double-layer aluminum plastic film by hot pressing, and the double-layer aluminum plastic film is provided with a weak point. 6.The high-safety pouch battery of claim 5, wherein, When the temperature and pressure of the weak point exceed the preset temperature and pressure, the weak point opens.

7. A method of manufacturing a high safety pouch battery, characterized by, A method for preparing a high-safety soft package battery according to any one of claims 1-6, comprising: coating the electric core with a soft package film; performing primary packaging on the soft package film to form a soft package bag with one open end; injecting electrolyte into the soft package bag through the opening; performing secondary packaging on the open end of the soft package bag to form a partition strip, which divides the soft package bag into a battery bag and an inhibitor bag, and the electric core is arranged in the battery bag; injecting a thermal runaway inhibitor into the inhibitor bag and sealing the inhibitor bag. 8.The method of claim 7, wherein the method further comprises, after the step of forming the pouch-shaped battery, the step of: Before performing secondary packaging on the soft package bag, a weak point is designed on the partition strip of the soft package bag. ​ 9.The method of claim 7, wherein the method further comprises, after the step of forming the first electrode layer, the step of: forming a second electrode layer on the first electrode layer. When performing secondary packaging on the soft package bag, hot melt adhesive is locally filled between the double-layer aluminum plastic film to form a weak point. 10.The method of claim 7, wherein the method further comprises, after the step of forming the pouch-shaped battery, the step of: When performing secondary packaging on the soft package bag, the width of the hot-pressed sealing of the double-layer aluminum plastic film is locally reduced to form a weak point. ​

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