Safety structure of large capacity battery

Abstract

The application discloses a safety structure of a large-capacity battery, which comprises a battery main body, a pressure relief port arranged on the battery main body, a cooling cavity for cooling combustible substances generated by a thermal runaway battery, and an adsorption cavity for adsorbing harmful substances; the cooling cavity is connected with the pressure relief port, and the pressure relief port is sealed and isolated from the cooling cavity by a pressure relief film. The cooling material in the cooling cavity cools the sprayed substances, so that the solid particles in the sprayed substances are blocked, the gaseous electrolyte is recondensed, the gaseous substances which cannot be condensed are cooled, the adsorption material filled in the adsorption cavity adsorbs the combustible gas, liquid and solid substances cooled by the cooling cavity, so that the substances discharged from the subsequent discharge port are non-combustible, and the secondary disasters such as explosion and fire of the battery caused by thermal runaway are avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a safety structure of a large-capacity battery and the large-capacity battery. BACKGROUND

[0002] Lithium batteries are a new type of battery with high specific energy, high voltage, long service life, no harm to the environment and no memory. A large amount of heat is generated in the working process of a lithium battery with a traditional structure, and the thermal conductivity of lithium battery materials is poor. Therefore, the heat inside the lithium battery with such a structure will accumulate rapidly, causing the temperature of the lithium battery to be too high, which may further cause the performance of the lithium battery to decrease or thermal runaway, and even cause combustion or explosion and other dangerous consequences.

[0003] The safety structure of a lithium battery has a heat dissipation function, and the battery is cooled and treated in other ways, such as setting a pressure relief port and a collection airbag. Improving the heat dissipation of the battery and cooling the battery are safety measures taken in advance, and setting a pressure relief port and a collection airbag are safety remedial measures taken when the battery actually experiences thermal runaway. Once the lithium battery experiences thermal runaway and the pressure relief port is opened, the electrolyte, positive and negative electrode materials and other substances inside the battery will be sprayed into the environment along with the high temperature inside the battery. These substances, especially the electrolyte, are extremely flammable substances, and the temperature when sprayed is above their ignition point. They will immediately catch fire in the air, igniting other substances near the battery and causing secondary damage. It is generally believed that a fire caused by thermal runaway of a lithium battery is difficult to extinguish, and one can only wait for the combustible materials inside the battery to burn out. Therefore, the main problem to be solved by the safety structure of the battery when the battery experiences thermal runaway is to reduce the degree of secondary damage.

[0004] Patent CN109088109A discloses a safe battery, which includes a battery assembly and a safety airbag. A collection airbag is arranged outside the pressure relief port, and the gas generated when the battery experiences thermal runaway is collected, and then diluted with more inert gas, so that the mixed gas is non-flammable. This treatment method has the following problems. On the one hand, the high-temperature gas sprayed from the pressure relief port of the battery has a high requirement for the temperature resistance of the collection airbag. On the other hand, once a large-capacity battery experiences thermal runaway, the amount of gas released is also very large. In addition, after being diluted with several times the volume of inert gas, the volume of the airbag will be very large. Therefore, this collection and dilution method is not suitable for large-capacity batteries, but only for small-capacity batteries.

[0005] Patents CN203225319U / CN201420537958.X / CN201521093352.2 / CN 108417757 A provide adsorption structure and adsorbent patents are directly adsorbed to the high-temperature substances directly sprayed from the battery and lack the link of cooling. When the general adsorbent such as activated carbon, molecular sieve and the like is adsorbed, the higher the temperature of the adsorbed substance, the worse the adsorption effect. For example, the adsorption temperature of activated carbon on gaseous substances is below 50 DEG C, and the temperature of the gas sprayed from the battery in thermal runaway is generally higher than 300 DEG C, and at this temperature, activated carbon will lose the adsorption function on gaseous substances, and instead has a desorption function on the adsorbed substances. Although the adsorbent can absorb the vaporized electrolyte at this temperature, it cannot adsorb flammable gas substances such as hydrogen, carbon monoxide and methane generated in the battery thermal runaway, and these substances still pose an explosion hazard in the battery thermal runaway. Therefore, it is necessary to cool the various substances sprayed from the battery before adsorption.

[0006] Patent 102934278A discloses a battery and a battery system, which has a cooling link before the battery thermal runaway substance is adsorbed. However, it uses a heat dissipation device, or a heat sink, to cool the substances sprayed from the battery in thermal runaway. This cooling method uses another system to cool the battery system, which inevitably makes the battery system complex and increases the cost. Other patents with cooling links, such as CN204271170U / CN 105977521 A / CN111640891A, use decomposable compounds or gasifiable compounds to produce gas to absorb heat. This can reduce the temperature of the battery in thermal runaway, but a large amount of gas produced by these cooling substances in a short time, combined with the gas released from the battery in thermal runaway, can also cause explosions and other accidents. Furthermore, if an adsorbent is used after these cooling materials, the amount of adsorbent used will be very large, making it impractical to achieve the purpose of adsorbing flammable gas. SUMMARY

[0007] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0008] The embodiment of the present application provides a safety structure of a large-capacity battery, which comprises a battery main body, a pressure relief port provided on the battery main body, a cooling cavity for cooling flammable substances generated by a thermal runaway battery, and an adsorption cavity for adsorbing harmful substances; the cooling cavity is connected with the pressure relief port, and the pressure relief port and the cooling cavity are sealed and isolated by a pressure relief film. The cooling cavity and the adsorption cavity are in communication, and a porous partition plate is arranged between the cooling cavity and the adsorption cavity.

[0009] Further, in the embodiments provided in the present application, the cooling cavity and the adsorption cavity can be arranged outside the battery, and the combustible material generated by the thermal runaway of the battery is sprayed out of the battery body through the pressure relief port into the cooling cavity outside the battery.

[0010] Further, in the embodiments provided in the present application, the cooling cavity and the adsorption cavity can also be arranged at the center position of the battery, and the combustible material generated by the thermal runaway of the battery enters the cooling cavity at the center position of the battery through the pressure relief port.

[0011] Further, in the embodiments provided in the present application, the porous partition plate is one of a porous metal mesh, a porous metal plate, and an inorganic fiber mesh.

[0012] Further, in the embodiments provided in the present application, the adsorption cavity is provided with an exhaust port. The exhaust port is provided with a moisture-proof film or a sealing film. The exhaust port is externally connected to an exhaust pipeline or an air bag.

[0013] Further, in the embodiments provided in the present application, the pressure relief film is a metal diaphragm. The cooling cavity is filled with one or a combination of a plurality of components selected from the group consisting of ceramic balls, honeycomb ceramic sheets, and graphite rods. The components of the ceramic balls and the honeycomb ceramic sheets are silicon carbide.

[0014] The adsorption cavity is filled with one or a combination of a plurality of components selected from the group consisting of activated carbon, porous silicon dioxide, molecular sieve, porous ceramic, and adsorption resin.

[0015] The present application has the beneficial effects that:

[0016] 1. When the battery is in thermal runaway and the pressure relief port is opened, various substances in the battery are sprayed outwards, first reaching the cooling cavity, and the sprayed substances are cooled by the cooling materials in the cooling cavity, so that part of the solid particles and the vaporized electrolyte in the sprayed substances are re-condensed, the gaseous substances are cooled, and conditions are created for the subsequent adsorption of combustible gas in the sprayed substances. Moreover, the materials used in the present application for cooling the substances sprayed out of the battery in thermal runaway are all physical cooling materials, which have good cooling effect on the substances, stable properties, and more importantly, no gas is generated, so that the amount and adsorption load of the subsequent adsorption material are greatly reduced.

[0017] 2. The adsorbent material filling the adsorption chamber adsorbs the combustible gases, liquids, and solids cooled in the cooling chamber, thereby significantly reducing the amount of combustible gas and the total gas volume emitted into the environment. Thus, the temperature of combustible gases emitted after passing through the cooling and adsorption chambers can be reduced below their auto-ignition point, and the gas concentration can be reduced below their explosion limits. With a suitable combination of cooling and adsorbent materials, the reduced gas emitted into the environment can achieve a colorless, odorless, and non-flammable effect, thereby avoiding secondary disasters such as explosions and fires caused by battery thermal runaway, and also reducing environmental pollution. Other advantages, objectives, and features of this application will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an overall structural diagram of the safety structure of the cylindrical high-capacity battery in Embodiment 1 of this application.

[0020] Figure 2 This is an overall structural diagram of the safety structure of the square high-capacity battery in Embodiment 2 of this application.

[0021] Figure 3 This is an overall structural diagram of the safety structure of the square high-capacity battery in Embodiment 3 of this application.

[0022] Figure 4 This is an overall cross-sectional view of the safety structure of the cylindrical high-capacity battery in Embodiment 4 of this application.

[0023] Figure 5 This is a cross-sectional view of the central column structure of the cylindrical high-capacity battery in Embodiment 4 of this application.

[0024] Labeling instructions: Positive terminal 11 / 21 / 31 / 41; Negative terminal 12 / 22 / 32 / 42; Battery body 13 / 25 / 35 / 45; Pressure relief port 14 / 24 / 34 / 44; Pressure relief membrane 15 / 23 / 33 / 43; Cooling chamber 16 / 26 / 36 / 46; Porous separator 17 / 27 / 37 / 47; Adsorption chamber 18 / 28 / 38 / 48; Discharge port 19 / 29 / 39 / 49; Discharge pipe 310; Detonation hole 410; Winded cell 411. Detailed Implementation

[0025] The present application will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description. It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not imply the presence or addition of one or more other elements or combinations thereof.

[0026] The technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] like Figures 1 to 3 As shown in the illustration, this application provides a safety structure for a large-capacity battery, including a battery body with a pressure relief port, a cooling chamber for cooling flammable substances generated by thermal runaway, and an adsorption chamber for adsorbing harmful substances. The cooling chamber is connected to the pressure relief port, and the pressure relief port and the cooling chamber are sealed and isolated by a pressure relief membrane. The cooling chamber is in communication with the adsorption chamber, and a porous partition is provided between the cooling chamber and the adsorption chamber.

[0028] Furthermore, in the embodiments provided in this application, the cooling chamber and the adsorption chamber can be located outside the battery, and the flammable substances generated by the thermal runaway of the battery are ejected from the battery body through the pressure relief port and enter the cooling chamber outside the battery.

[0029] Furthermore, in the embodiments provided in this application, the cooling chamber and the adsorption chamber can also be located at the center of the battery, and the flammable substances generated by the thermal runaway of the battery enter the cooling chamber at the center of the battery through the pressure relief port.

[0030] Furthermore, in the embodiments provided in this application, the porous partition is one of a porous metal mesh, a porous metal plate, or an inorganic fiber mesh.

[0031] Furthermore, in the embodiments provided in this application, the adsorption chamber is provided with an exhaust port. The exhaust port is provided with a moisture-proof membrane, or a sealing membrane. An exhaust pipe, or an airbag, is externally connected to the exhaust port.

[0032] Furthermore, in the embodiments provided in this application, the pressure relief membrane is a metal diaphragm. The cooling chamber is filled with one or more combinations of ceramic balls, honeycomb ceramic sheets, and graphite rods. The ceramic balls and honeycomb ceramic sheets are composed of silicon carbide. The adsorption chamber is filled with one or more combinations of activated carbon, porous silica, molecular sieves, porous ceramics, and adsorption resins.

[0033] Example 1

[0034] like Figure 1 As shown, a safety structure for a cylindrical high-capacity battery, such as... Figure 1As shown, the battery includes a cooling chamber 16 and an adsorption chamber 18. The positive electrode 11 and negative electrode 12 of the high-capacity battery 13 are located on the same side of the top surface of the battery. A pressure relief port 14 is located on the bottom surface of the cylindrical battery casing. The pressure relief port 14 seals the battery into a closed structure through a pressure relief membrane 15. The cooling chamber 16 is located at the bottom of the battery 13, adjacent to the outside of the pressure relief port 14. An adsorption chamber 18 is located below the cooling chamber 16, with a porous metal plate 17 between the cooling chamber 16 and the adsorption chamber 18. A discharge port 19 is located at the bottom of the adsorption chamber. The cooling chamber is filled with… The ceramic balls are filled with X13 type molecular sieve balls in the adsorption chamber, and a moisture-proof membrane is attached to the bottom discharge port.

[0035] When a battery experiences thermal runaway, causing the pressure relief port to open, high-temperature substances inside the battery enter the cooling chamber through the pressure relief port. The ceramic balls in the cooling chamber cool these substances, causing some solid particles and vaporized electrolyte in the discharged material to re-condense. This creates conditions for the adsorption of flammable gases and liquids in the subsequently discharged material. On the other hand, after being cooled in the cooling chamber, the various substances enter the adsorption chamber, where molecular sieve adsorbents adsorb all the liquids and most of the flammable gases. Small molecule gases that are not adsorbed, such as nitrogen and nitrogen dioxide, are discharged through the exhaust port. By cooling and adsorbing the various substances generated after battery thermal runaway before release, the dangers of explosion and fire are avoided.

[0036] Example 2

[0037] like Figure 2 As shown, a safety structure for a square high-capacity battery, such as Figure 2 As shown, the battery includes a cooling chamber 26 and an adsorption chamber 28. The positive electrode 21 and negative electrode 22 of the high-capacity battery 25 are located on the same side of the top surface of the battery. The pressure relief port 24 is located on the upper part of the side casing of this square battery. The pressure relief port 24 seals the battery into a closed structure through the pressure relief membrane 25. The cooling chamber 26 is located on the upper side of the battery, adjacent to the outside of the pressure relief port 24. The adsorption chamber 28 is located below the cooling chamber 26. A porous fiber mesh 27 is provided between the cooling chamber 26 and the adsorption chamber 28. A discharge port 29 is provided at the bottom of the adsorption chamber. The cooling chamber is filled with honeycomb ceramic body, and the adsorption chamber is filled with cylindrical activated carbon granules. A sealing membrane is attached to the discharge port at the bottom.

[0038] When a battery experiences thermal runaway, causing the pressure relief port to open, high-temperature substances inside the battery enter the cooling chamber through the pressure relief port. The ceramic balls in the cooling chamber cool these substances, causing some solid particles and vaporized electrolyte in the discharged material to re-condense. This creates conditions for the adsorption of flammable gases and liquids in the subsequently discharged material. On the other hand, after being cooled in the cooling chamber, the various substances enter the adsorption chamber, where molecular sieve adsorbents adsorb all the liquids and most of the flammable gases. Small molecule gases that are not adsorbed, such as nitrogen and nitrogen dioxide, are discharged through the exhaust port. By cooling and adsorbing the various substances generated after battery thermal runaway before release, the dangers of explosion and fire are avoided.

[0039] Example 3

[0040] like Figure 3 As shown, a safety structure for a square high-capacity battery, such as Figure 3 As shown, the battery includes a cooling chamber 36 and an adsorption chamber 38. The positive electrode 31 and negative electrode 32 of the high-capacity battery 35 are located on the same side of the top surface of the battery. The positive and negative electrodes are led out from the side of the cooling chamber through an electrode adapter. The pressure relief port 34 is located on the top surface of this square battery on the same side as the positive and negative electrodes. The pressure relief port is sealed into a closed structure by a pressure relief membrane 33. The cooling chamber 36 is located on the top surface of the battery, adjacent to the outside of the pressure relief port 34. The adsorption chamber 38 is located above the cooling chamber. A metal mesh 37 is provided between the cooling chamber 36 and the adsorption chamber 38. The exhaust port 39 is located above the adsorption chamber. An exhaust pipe 310 is installed on the exhaust port. The opening of the exhaust pipe is located in a safe area away from flammable materials and is sealed with a plug. The cooling chamber is filled with graphite rods, and the adsorption chamber is filled with activated carbon powder.

[0041] When a battery experiences thermal runaway, causing the pressure relief port to open, high-temperature substances inside the battery enter the cooling chamber through the pressure relief port. The ceramic balls in the cooling chamber cool these substances, causing some solid particles and vaporized electrolyte in the discharged material to re-condense. This creates conditions for the adsorption of flammable gases and liquids in the subsequently discharged material. On the other hand, after being cooled in the cooling chamber, the various substances enter the adsorption chamber, where molecular sieve adsorbents adsorb all the liquids and most of the flammable gases. Small molecule gases that are not adsorbed, such as nitrogen and nitrogen dioxide, are discharged through the exhaust port. By cooling and adsorbing the various substances generated after battery thermal runaway before release, the dangers of explosion and fire are avoided.

[0042] Example 4

[0043] like Figure 4 , Figure 5As shown, a safety structure for a cylindrical high-capacity battery includes a positive electrode 41, a negative electrode 42, and a wound cell 411 of a cylindrical high-capacity battery 45. The safety structure is located on the central pillar of the cylindrical battery, and from the bottom up, consists of a detonation hole 410, a pressure relief port 44, a cooling chamber 46, a porous fiber mesh 47, an adsorption chamber 48, and a discharge port 49. The pressure relief port 44 seals the battery into a closed structure through a pressure relief membrane 43. The cooling chamber 46 is located above the pressure relief port 44, adjacent to the outer side of the pressure relief port 44. An adsorption chamber 48 is located above the cooling chamber 46, with a porous fiber mesh 47 between the cooling chamber 46 and the adsorption chamber 48. The discharge port 49 is located above the adsorption chamber. The cooling chamber is filled with honeycomb ceramic material, the adsorption chamber is filled with cylindrical activated carbon granules, and a sealing membrane is attached to the discharge port at the top of the central pillar.

[0044] When thermal runaway occurs in the battery, causing an increase in internal pressure, the pressure relief port at the bottom of the center post opens. High-temperature materials inside the battery enter the cooling chamber through the lower detonation hole. There, ceramic balls cool the materials, causing some solid particles and vaporized electrolyte in the released material to re-condense. This creates conditions for the adsorption of flammable gases and liquids in the subsequently released material. Meanwhile, after cooling, the materials enter the adsorption chamber, where molecular sieve adsorbents adsorb all liquids and most flammable gases. Small molecules such as nitrogen and nitrogen dioxide that are not adsorbed are released through the exhaust port. By cooling and adsorbing the various substances generated after battery thermal runaway, the battery can release them without causing explosions or fires.

[0045] Although the embodiments of this application have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this application. Other modifications can be readily implemented by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, this application is not limited to the specific details and examples shown and described herein.

Claims

1. A safety structure for a high-capacity battery, wherein the high-capacity battery is a cylindrical high-capacity battery, comprising a battery body, wherein the battery body is provided with a pressure relief port, characterized in that, The safety structure is located on the central column of the cylindrical battery, including a cooling chamber for cooling down flammable materials generated by the thermal runaway battery, and an adsorption chamber for adsorbing harmful substances. The pressure relief port is located at the bottom of the central column, and the cooling chamber is connected to the pressure relief port. The pressure relief port and the cooling chamber are sealed and isolated by a pressure relief membrane. The flammable material inside the battery enters the cooling chamber at the center of the battery through the detonation hole and the pressure relief port. The cooling chamber is filled with a material that provides physical cooling. The cooling chamber is connected to the adsorption chamber, and a porous partition is provided between the cooling chamber and the adsorption chamber; An exhaust port is provided at the upper part of the adsorption chamber.

2. The safety structure of a high-capacity battery as described in claim 1, characterized in that, The porous partition is one of porous metal mesh, porous metal plate, or inorganic fiber mesh.

3. The safety structure of a high-capacity battery as described in claim 1, characterized in that, The exhaust port is provided with a moisture-proof membrane or a sealing membrane.

4. The safety structure of a high-capacity battery as described in claim 3, characterized in that, The exhaust port is externally connected to an exhaust pipe.

5. The safety structure of a high-capacity battery as described in claim 1, characterized in that, The pressure relief membrane is a metal diaphragm.

6. The safety structure of a high-capacity battery as described in claim 1, characterized in that, The cooling chamber is filled with one or more of the following: ceramic balls, honeycomb ceramic sheets, porous ceramics, metal materials, and graphite rods.

7. The safety structure of a high-capacity battery as described in claim 6, characterized in that, The ceramic spheres, honeycomb ceramic sheets, and porous ceramics are composed of silicon carbide.

8. The safety structure of a high-capacity battery as described in claim 1, characterized in that, The adsorption chamber is filled with one or more of the following: activated carbon, porous silica, molecular sieve, porous ceramic, and adsorption resin.

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