Battery module capable of effectively preventing thermal runaway diffusion, protection method thereof and energy storage device

Abstract

The invention relates to a battery module capable of effectively preventing thermal runaway diffusion, a protection method of the battery module and an energy storage device. The battery module comprises an upper shell, a lower box body, a battery module, a pressure relief flow guide part, a panel structural part and a CCS assembly, the upper shell and the lower box body form a containing cavity; at least one group of battery modules are arranged in the accommodating cavity; the battery module comprises at least one battery monomer, the battery monomers are connected in series, a safety valve is arranged on each battery monomer, and a pressure relief flow guide part is arranged above the safety valve; a panel structural member is arranged at one end of the battery module along the arrangement direction of the battery monomers; and a CCS assembly is arranged above the battery module. According to the invention, gas and electrolyte can be separated after the single battery is sprayed, and are respectively and directionally discharged, so that the situation that other normal single batteries or modules are damaged due to disordered splashing of sprayed objects is avoided, and spontaneous combustion or explosion of the battery module is avoided.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery module capable of effectively preventing thermal runaway from spreading, a protection method thereof, and an energy storage device. Background Art

[0002] With the rapid development of the energy storage field, the energy density of battery cells has gradually increased, and the performance and safety requirements of battery systems have also increased. When the temperature difference of battery cells is large, thermal runaway may occur in the battery cells. After the thermal runaway of the battery cells, the material ejected from the safety valve of the battery cells gradually fills the entire battery module, and the ejected gas continuously increases the internal pressure of the battery module. In order to prevent the rapid expansion of the gas in the battery module from deforming and rupturing the shell, an explosion-proof valve is usually set on the battery module shell. When the pressure in the battery module is large enough, it will break through the barrier of the explosion-proof valve to achieve the purpose of pressure relief. At this time, the high-temperature electrolyte or burning fluid ejected from the battery cells will be discharged from the explosion-proof valve together, which may cause damage to other battery modules or electronic components; at the same time, the high-temperature electrolyte ejected from the battery cells has no directional control in the battery module, and may indiscriminately sputter onto other normal battery cells or electronic components, causing corrosion, burning, damage, short circuit or even fire and explosion of structures such as battery cells, battery module covers or copper bars. Therefore, it is particularly important to suppress the spread of the ejected material after the battery spray valve and prevent the spread of thermal runaway to reduce safety risks.

[0003] CN116417726A discloses a battery pack, an energy storage device and an electrical device, in which an upper cover plate and a lower cover plate cooperate to form a liquid storage cavity, and a flow guide channel and a flow guide surface are provided at the same time, so that the sprayed material of the explosion-proof valve of the battery cell drips onto the flow guide surface under the effect of gravity or the reflection of the upper cover plate, and is discharged into the liquid storage cavity from the flow guide surface. However, the sprayed high-temperature electrolyte is in a gas-liquid mixed state, and it is difficult to directly liquefy into droplets and flow into the liquid storage cavity under the effect of gravity or the reflection of the upper cover plate alone. Part of the high-temperature electrolyte will be discharged from the battery module together with the gas in the sprayed material, causing damage to other battery modules or electronic components. At the same time, after the high-temperature electrolyte flows into the liquid storage cavity, the heat is difficult to diffuse, which is easy to cause local high temperature, and the temperature in the battery module rises uncontrollably.

[0004] CN214411404U discloses a lithium battery pack with a function of preventing the spread of thermal runaway. The battery pack is provided with a high-temperature resistant ceramic plate between the box cover and the battery cell. The heat-resistant and heat-insulating effects of the ceramic plate are utilized to prevent the heat from spreading outward after the battery cell spray valve, thereby avoiding direct damage to the box cover. However, the design of adding a high-temperature resistant ceramic plate between the battery cell and the box cover can only prevent the heat from spreading to the box cover, but cannot effectively discharge and separate the gas and electrolyte after the battery cell spray valve, and cannot drain the electrolyte. The disordered spraying of the electrolyte may cause damage to the normal battery cells in the battery module, causing the spread of thermal runaway.

[0005] CN217009442U discloses a battery module, a battery pack and a vehicle, wherein a bracket is provided in the battery module, and at least a part of the explosion-proof valve is covered on the bracket to prevent the high-temperature gas discharged from the explosion-proof valve from being directly ejected, thereby avoiding the influence of the high-temperature gas on other battery modules, and at the same time, a first exhaust channel and a plurality of second exhaust channels are provided, which is conducive to the rapid discharge of the high-temperature gas from two different directions. However, the flow separation of electrolyte and gas cannot be achieved, and the high-temperature electrolyte or the fluid in the burning state will be discharged through the explosion-proof valve together after the battery cell spray valve is opened, which may cause damage to other normal battery modules or electronic components, thereby causing the spread of thermal runaway, and the structural design is relatively complex, which increases the difficulty of assembly and the cost of accessories.

[0006] Therefore, there is an urgent need to develop a battery module that can effectively prevent the spread of thermal runaway, so as to solve the problem of gas pressure release in the battery module when the battery cell sprays the valve, and the problem of disorderly splashing of high-temperature electrolyte endangering normal battery cells or modules. Summary of the invention

[0007] In view of the above problems, the purpose of the present invention is to provide a battery module and its protection method and energy storage device that can effectively prevent the spread of thermal runaway. Compared with the prior art, the present invention can separate the gas and electrolyte after the battery cell spray valve, and discharge them in a directional manner respectively, so as to avoid the disorderly splashing of the sprayed material to endanger other normal battery cells or modules, and avoid the spontaneous combustion or explosion of the battery module.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a battery module that can effectively prevent the spread of thermal runaway, the battery module comprising an upper shell, a lower box, a battery module, a pressure relief guide, a panel structure and a CCS assembly;

[0010] The upper shell and the lower box body form a accommodating chamber;

[0011] At least one battery module is arranged in the accommodating cavity;

[0012] The battery module comprises at least one battery cell, each battery cell is connected in series, each battery cell is provided with a safety valve, and a pressure relief guide is provided above the safety valve;

[0013] A panel structure is provided at one end of the battery module along the arrangement direction of the battery cells;

[0014] A CCS component is arranged above the battery module.

[0015] In the present invention, the design of the pressure relief guide member can timely relieve pressure and directionally discharge the ejected material in the battery module, protect the batteries and electronic components around the thermal runaway monomer from damage, prevent the upper shell from deformation or damage, reduce the risk of thermal runaway spread, and reduce the losses after thermal runaway.

[0016] In the present invention, at least one battery module is arranged in the accommodating cavity, for example, it may be 1, 2, 3 or 4, but it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0017] In the present invention, the battery module includes at least one battery cell, for example, it can be 1, 2, 3 or 4, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] Preferably, a heat insulating pad is provided between the side surfaces of adjacent battery cells.

[0019] Preferably, the pressure relief guide member includes a guide channel, a pressure relief groove, a cover plate, a convex hump, a movable barrier sheet, a converging channel and a connecting pipe.

[0020] Preferably, the guide channel is arranged above the battery module, and the guide channel includes corresponding upper and lower walls. The guide channel extends from one end close to the panel structure to the other end away from the panel structure, and the vertical distance between the lower wall of the guide channel and the upper surface of the battery module gradually increases.

[0021] Preferably, a diversion outlet is arranged at one end of the diversion channel close to the panel structure, and the other end is sealed.

[0022] Preferably, a pressure relief groove is provided on the lower wall corresponding to the position of the safety valve in the battery module.

[0023] Preferably, the bottom of the pressure relief groove protrudes from the lower surface of the lower wall, the top of the pressure relief groove protrudes from the upper surface of the lower wall and does not contact the upper wall, the bottom opening of the pressure relief groove is in circumferential contact with the corresponding safety valve, and the top opening of the pressure relief groove is provided with a cover plate, and the cover plate, the pressure relief groove and the safety valve constitute a closed space.

[0024] Preferably, one end of the cover plate away from the diversion outlet is fixedly connected to the pressure relief groove, and the other end is movably in contact with the pressure relief groove.

[0025] Preferably, at least one convex hump is arranged at intervals on the bottom surface of the upper wall of the guide channel, and the convex hump is arranged between adjacent cover plates.

[0026] In the present invention, the bottom surface of the upper wall of the guide channel is provided with at least one convex hump at intervals, for example, it can be 1, 2, 3 or 4, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] Preferably, the movable barrier piece is arranged in the diversion channel and is located between the diversion outlet and the first pressure relief groove close to the diversion outlet. The upper end of the movable barrier piece is fixedly connected to the upper wall, and the other end is in movable contact with the lower wall.

[0028] Preferably, the confluence channel is arranged below the diversion outlet, and the diversion outlet is connected to the confluence channel via a bend pipe.

[0029] Preferably, a drain port is provided at the bottom of the confluence channel.

[0030] Preferably, a connecting pipe is provided at the upper portion of the cavity of the confluence channel.

[0031] Preferably, along the extension direction of the diversion channel, the maximum height of the first pressure relief groove protruding from the lower wall near the diversion outlet is h1, the maximum height of the second pressure relief groove protruding from the lower wall is h2, ..., and the maximum height of the last pressure relief groove protruding from the lower wall is h i , the h1, h2, ..., h i Incrementing successively, i is a positive integer.

[0032] Preferably, a phase change material accommodating cavity is provided in the convex hull.

[0033] Preferably, the inner bottom surface of the converging channel is coated with an electrolyte inhibitor.

[0034] Preferably, the connecting pipe is communicated with an explosion-proof valve, and the explosion-proof valve is fixedly arranged on the panel structure.

[0035] Preferably, the explosion-proof valve comprises an explosion-proof membrane and a protective cover arranged outside the explosion-proof membrane.

[0036] In a second aspect, the present invention provides a method for protecting a battery module that can effectively prevent the spread of thermal runaway, wherein the protection method uses the battery module that can effectively prevent the spread of thermal runaway according to the first aspect of the present invention;

[0037] The protection method comprises the following steps:

[0038] When a battery cell experiences thermal runaway, the safety valve of the battery cell ruptures and opens, spraying a jet containing electrolyte and gas. The jet enters the pressure relief guide and separates the electrolyte and gas inside the pressure relief guide, and then the gas and electrolyte are discharged from the battery module respectively.

[0039] In the present invention, the jet containing electrolyte and gas is timely depressurized and diverted in the pressure relief guide, thereby protecting the surrounding batteries and electronic components of the battery cell in thermal runaway from damage, preventing the upper shell from deformation or damage, reducing the risk of thermal runaway spreading, and reducing the losses after thermal runaway.

[0040] Preferably, the protection method comprises the following steps:

[0041] When a battery cell experiences thermal runaway, the safety valve of the battery cell ruptures and opens, spraying out a jet containing electrolyte and gas. The impact force of the jet causes the cover of the pressure relief groove above the safety valve to open. Due to the obstruction of the upper wall and cover of the diversion channel, the movement of the jet changes from vertically spraying upward to flowing out in the direction of the diversion outlet.

[0042] During the process of the jet flowing out of the guide channel, the high-temperature gas-liquid mixed electrolyte contacts the convex hull filled with the phase change material in the guide channel, so that the temperature of the high-temperature gas-liquid mixed electrolyte is reduced and droplets are formed and condensed on the surface of the convex hull. Under the action of gravity, the electrolyte drops to the lower wall of the guide channel, thereby realizing the first separation of the electrolyte and gas in the jet;

[0043] The electrolyte flows to the guide outlet under the action of inertia and gravity, and the electrolyte and gas in the guide channel exert force on the movable barrier piece to open the movable barrier piece to form an opening, and the electrolyte and gas enter the converging channel through the guide outlet and the elbow;

[0044] In the convergence channel, the electrolyte reacts with the electrolyte inhibitor to reduce the release of heat, and then the electrolyte is discharged from the battery module from the drain port at the bottom of the convergence channel, and the gas is discharged from the connecting pipe at the upper part of the convergence channel cavity, thereby achieving a second separation of gas and electrolyte. Under the action of the gas, the explosion-proof membrane of the explosion-proof valve ruptures, and the protective cover is pushed open by the gas to form an opening, which has a pressure relief effect on the battery module.

[0045] In a third aspect, the present invention provides an energy storage device, wherein the energy storage device comprises the battery module capable of effectively preventing the spread of thermal runaway as described in the first aspect of the present invention.

[0046] In the present invention, the battery module is used in an energy storage device, and the energy storage device may be, for example, an energy storage system, which can effectively prevent the spread of thermal runaway and improve the safety of the energy storage system.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] (1) The battery module provided by the present invention is designed with a pressure relief guide member, which can timely relieve pressure and directionally discharge battery ejection materials in the battery module when thermal runaway occurs, thereby protecting the surrounding batteries and electronic components of the battery cells in thermal runaway from damage, preventing deformation or damage to the upper shell, reducing the risk of thermal runaway spreading, and reducing losses after thermal runaway.

[0049] (2) The pressure relief guide member provided by the present invention can discharge the battery ejection material in a directional manner through the provision of the guide channel and the movable barrier sheet, and isolate the normal battery module, thereby reducing the risk of thermal runaway diffusion, and at the same time preventing a large amount of air from entering the guide channel, thereby effectively preventing the combustible gas in the battery monomer ejection material from coming into contact with a large amount of air and causing a fire.

[0050] (3) The arrangement of the convex bump in the pressure relief guide provided by the present invention can liquefy the high-temperature gas-liquid mixed electrolyte, reduce the temperature of the electrolyte, and achieve the purpose of gas-liquid separation.

[0051] (4) The battery module provided by the present invention can isolate thermal runaway battery cells from normal battery cells through the design of pressure relief grooves, cover plates and thermal insulation pads, prevent the battery cells from spraying electrolyte due to thermal runaway and causing harm to normal battery cells, and effectively prevent the spread of thermal runaway.

[0052] (5) In the battery module provided by the present invention, an electrolyte inhibitor is coated on the inner bottom surface of the confluence channel, so that the high-temperature electrolyte sprayed out of the thermal runaway battery cells can be promptly processed and discharged, thereby reducing the harm of direct discharge of the electrolyte to the energy storage system and the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic diagram of the structure of a battery module provided in a specific embodiment of the present invention;

[0054] Figure 2 and Figure 3 for Figure 1 A partial structural schematic diagram of a battery module is provided;

[0055] Figure 4 for Figure 1 A schematic diagram of the structure of the flow guide channel in the provided battery module;

[0056] Figure 5 for Figure 4 Main cross-sectional view of the middle diversion channel;

[0057] Figure 6 for Figure 5 A partial enlarged view of the circled part A;

[0058] Figure 7 for Figure 5A partial enlarged view of the circled portion B;

[0059] Among them: 1-battery module; 2-upper shell; 3-lower box; 4-panel structure; 5-explosion-proof valve; 6-pressure relief guide; 7-CCS assembly; 8-safety valve; 9-battery monomer; 10-thermal insulation pad;

[0060] 601-pressure relief groove; 602-cover plate; 603-convex bump; 604-movable barrier plate; 605-flow diversion channel; 606-convex channel; 607-connecting pipe; 608-sealed end of the flow diversion channel; 609-upper wall; 610-lower wall; 611-flow diversion outlet; 612-inner bottom surface of the converging channel; 613-elbow pipe. DETAILED DESCRIPTION

[0061] It should be understood that, in the description of the present invention, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0062] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0063] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0064] In a specific embodiment, the present invention provides a battery module that can effectively prevent the spread of thermal runaway, such as Figure 1 , Figure 2 and Figure 3As shown, the battery module includes an upper shell 2, a lower box 3, a battery module 1, a pressure relief guide 6, a panel structure 4 and a CCS assembly 7. The upper shell 2 and the lower box 3 constitute a accommodating cavity, and at least one group of battery modules 1 is arranged in the accommodating cavity. The battery module 1 includes at least one battery cell 9, each battery cell 9 is connected in series, and each battery cell 9 is provided with a safety valve 8. The pressure relief guide 6 is arranged above the safety valve 8. A panel structure 4 is arranged at one end of the battery module 1 along the arrangement direction of the battery cells 9, and a CCS assembly 7 is arranged above the battery module 1.

[0065] In the present invention, the upper shell 2 is arranged above the battery module, and the upper shell 2 and the lower box 3 form a sealed space, i.e., a receiving chamber, through a seal and a fixing, for receiving the battery module 1 and limiting the position of the battery module 1; the lower box 3 is located below the battery module 1, for supporting the weight of the battery module 1; a panel structure 4 is arranged at one end of the battery module 1 along the arrangement direction of the battery cells 9, for installing the connector of the battery module, etc.; the pressure relief guide 6 can be used for separation and directional discharge of ejected materials after the safety valve 8 ruptures; the CCS assembly 7 of the present invention is a well-known CCS assembly for battery modules in the art, generally including a bus bar, a positive electrode connection part and a negative electrode connection part are arranged on the bus bar, and the positive electrode connection part and the negative electrode connection part are respectively welded to the positive electrode and the negative electrode of the battery cell 9 to realize the electrical connection between the bus bar and the battery cell 9. The CCS assembly 7 is used to collect the temperature and other status information of the battery cell 9.

[0066] In the present invention, at least one battery module 1 is arranged in the accommodating cavity, for example, it can be 1, 2, 3 or 4, but it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0067] In the present invention, the battery module 1 includes at least one battery cell 9, for example, it can be 1, 2, 3 or 4, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0068] In some of the embodiments, a heat insulating pad 10 is disposed between the side surfaces of adjacent battery cells 9 .

[0069] In the present invention, the setting of the thermal insulation pad 10 can play the role of insulation and heat insulation. The material of the thermal insulation pad 10 can adopt any conventional material commonly used for thermal insulation pads 10 in the field, such as glass fiber, ceramic fiber, vulcanized layer insulation foam, pre-oxidized silk fiber, etc. The material of the thermal insulation pad 10 generally needs to be selected according to the fire resistance grade and thickness. The general fire resistance temperature is 150-1500℃, and the material thickness is 0.1-10mm.

[0070] In some embodiments, such as Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, the pressure relief guide member 6 includes a guide channel 605 , a pressure relief groove 601 , a cover plate 602 , a convex hump 603 , a movable blocking piece 604 , a converging channel 606 and a connecting pipe 607 .

[0071] In some of the embodiments, the guide channel 605 is arranged above the battery module 1, and the guide channel 605 includes a corresponding upper wall 609 and a lower wall 610. The guide channel 605 extends from one end close to the panel structure 4 to the other end away from the panel structure 4, and the vertical distance between the lower wall 610 of the guide channel 605 and the upper surface of the battery module 1 gradually increases.

[0072] In the present invention, the “guiding channel 605 extends from one end close to the panel structure 4 to the other end away from the panel structure 4, and the vertical distance between the lower wall 610 of the guiding channel 605 and the upper surface of the battery module 1 gradually increases” means: along the direction in which the guiding channel 605 extends, the lower wall 610 of the guiding channel 605 is inclined upward at a certain angle at one end away from the panel structure 4, so that the electrolyte can be smoothly discharged from the guiding channel 605 under the action of inertia and gravity. The direction of the upper wall 609 of the guiding channel 605 can be parallel to the upper surface of the battery module 1, and can also be parallel to the lower wall 610, such as Figure 4 As shown in , when the upper surface of the battery module 1 is horizontal, the end of the lower wall 610 away from the panel structure 4 is inclined upward at a certain angle compared to the horizontal plane, and the upper wall 609 is horizontal.

[0073] In some of the embodiments, a diversion outlet 611 is provided at one end of the diversion channel 605 close to the panel structure 4, and the other end is sealed.

[0074] In the present invention, the guide channel 605 has a certain accommodating space for accommodating the ejected material from the pressure relief groove 601, the convex bump 603 and the battery cell 9. The shape of the guide channel 605 is not particularly limited, for example, it can be a circular tube or a rectangular parallelepiped. The guide channel 605 is only provided with one outlet, namely the guide outlet 611, and the other end is sealed and recorded as the guide channel sealing end 608. Through the above-mentioned arrangement, after the ejected material is sprayed into the guide channel 605 through the pressure relief groove 601, it can only be discharged in the direction of the guide outlet 611. At the same time, due to the effect of the existing gas at the guide channel sealing end 608, the subsequent ejected material can only be discharged in the direction of the guide outlet 611.

[0075] In some of the embodiments, the lower wall 610 is provided with a pressure relief groove 601 corresponding to the position of the safety valve 8 in the battery module 1 .

[0076] In some of the embodiments, the bottom of the pressure relief groove 601 protrudes from the lower surface of the lower wall 610, the top of the pressure relief groove 601 protrudes from the upper surface of the lower wall 610 and does not contact the upper wall 609, the bottom opening of the pressure relief groove 601 is in circumferential contact with the corresponding safety valve 8, and the top opening of the pressure relief groove 601 is provided with a cover plate 602, and the cover plate 602, the pressure relief groove 601 and the safety valve 8 constitute a closed space.

[0077] In the present invention, the size of the bottom opening of the pressure relief groove 601 matches the size of the safety valve 8, and can completely surround the safety valve 8, and the contact between the circumference of the pressure relief groove 601 and the lower wall 610 is sealed, and the cover plate 602, the pressure relief groove 601 and the safety valve 8 form a closed space. In the present invention, by setting the top of the pressure relief groove 601 to protrude from the upper surface of the lower wall 610 and not in contact with the upper wall 609, it is possible to prevent the liquefied dripping electrolyte from splashing into the pressure relief groove 601 when the cover plate 602 is in an open state, thereby avoiding the formation of secondary splashing.

[0078] In some of the embodiments, one end of the cover plate 602 away from the guide outlet 611 is fixedly connected to the pressure relief groove 601 , and the other end is movably in contact with the pressure relief groove 601 .

[0079] It should be noted that the size of the cover plate 602 in the present invention matches the size of the top opening of the pressure relief groove 601 so as to achieve sealing, and the space between the top of the pressure relief groove 601 and the upper wall 609 can meet the requirements of the cover plate 602 being opened without contacting the upper wall 609. In the present invention, by setting "one end of the cover plate 602 away from the diversion outlet 611 is fixedly connected to the pressure relief groove 601, and the other end is in active contact with the pressure relief groove 601", the cover plate 602 and the pressure relief groove 601 can form a first active angle, and the opening of the first active angle faces the diversion outlet 611. Generally, it is preferred to control the first active angle to be 0-90°, so as to ensure that the gas ejected by the rupture of the safety valve 8 can open the cover plate 602, so that the ejected material can be ejected smoothly from the pressure relief groove 601, and the opened cover plate 602 can change the ejection direction of the ejected material to a certain extent, preventing most of the ejected material from flowing to the end away from the diversion outlet 611.

[0080] In some of the embodiments, at least one convex bump 603 is disposed at intervals on the bottom surface of the upper wall 609 of the guide channel 605 , and the convex bump 603 is disposed between adjacent cover plates 602 .

[0081] In the present invention, the shape of the convex bump 603 is not particularly limited, for example, it can be a hemisphere, a cone, a pyramid, a cuboid, a cube or a polyhedron of other shapes, preferably a hemisphere, and the spherical surface faces the lower wall 610 of the guide channel 605. In the present invention, by arranging the convex bump 603 between adjacent cover plates 602, the convex bump 603 and the cover plate 602 can be staggered, and the positions do not correspond to each other and overlap, so as to prevent the liquid electrolyte on the convex bump 603 from dripping into the pressure relief groove 601 when the cover plate 602 is in the open state, and avoid secondary splashing of the electrolyte.

[0082] In the present invention, at least one convex bump 603 is arranged at intervals on the bottom surface of the upper wall 609 of the guide channel 605, for example, it can be 1, 2, 3 or 4, but it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable. In the present invention, by controlling the number of convex bumps 603, the contact area between the electrolyte and the convex bump 603 can be increased, the cooling efficiency of the electrolyte and the separation efficiency of the electrolyte and the gas can be improved, and the shapes of the multiple convex bumps 603 can be the same or different, and the distances of the multiple convex bumps 603 from the lower wall 610 can be the same or different, but it is necessary to ensure that the bottom of the convex bump 603 does not contact the lower wall 610, so that the remaining space can ensure that the gas in the ejecta and the condensed electrolyte are smoothly discharged from the guide channel 605.

[0083] In some of the embodiments, the movable barrier plate 604 is disposed in the diversion channel 605 and is located between the diversion outlet 611 and the first pressure relief groove 601 close to the diversion outlet 611 . The upper end of the movable barrier plate 604 is fixedly connected to the upper wall 609 , and the other end is in movable contact with the lower wall 610 .

[0084] In some embodiments, the confluence channel 606 is disposed below the diversion outlet 611 , and the diversion outlet 611 is connected to the confluence channel 606 via a bend pipe 613 .

[0085] In the present invention, by controlling "the upper end of the movable barrier piece 604 is fixedly connected to the upper wall 609, and the other end is movably in contact with the lower wall 610", the movable barrier piece 604 can be made to droop naturally under the action of gravity, and the size of the movable barrier piece 604 can ensure that the bottom of the movable barrier piece 604 is in contact with the lower wall 610 in the natural state, so that the diversion channel 605 is in a sealed state. When the movable barrier piece 604 is separated from the lower wall 610 under the action of the gas and electrolyte in the diversion channel 605, the movable barrier piece 604 opens to form an opening and the movable barrier piece 604 forms a second movable angle with the vertical direction of the fluid flow, so that the gas and electrolyte flow out from the diversion outlet 611 and enter the confluence channel 606 through the bend 613. The movable barrier sheet 604 in the present invention serves to disconnect or connect the guide channel 605 and the confluence channel 606, which is equivalent to a one-way valve, allowing the gas and electrolyte in the guide channel 605 to flow into the confluence channel 606 in one direction, and preventing the gas and liquid in the confluence channel 606 from flowing back into the guide channel 605, thereby protecting other battery modules 1 without safety hazards, and preventing a large amount of air from entering the guide channel 605, effectively preventing the combustible gas in the ejection of the battery cell 9 from coming into contact with a large amount of air and catching fire, thereby further controlling safety hazards.

[0086] In the present invention, by setting the confluence channel 606 below the guide outlet 611, it can be used to converge the gas and electrolyte in the guide channels 605 on different battery modules 1, and the confluence channel 606 and the guide channel 605 are connected through the bend pipe 613, so that the height difference is used to facilitate the discharge of the electrolyte and inhibit the backflow of the electrolyte.

[0087] In some embodiments, a drain port (not shown) is disposed at the bottom of the confluence channel 606 .

[0088] In some embodiments, a connecting pipe 607 is disposed at the upper portion of the cavity of the confluence channel 606 .

[0089] In some embodiments, along the extension direction of the guide channel 605, the maximum height of the first pressure relief groove 601 protruding from the lower wall 610 close to the guide outlet 611 is h1, the maximum height of the second pressure relief groove 601 protruding from the lower wall 610 is h2, ..., the maximum height of the last pressure relief groove 601 protruding from the lower wall 610 is h i , the h1, h2, ..., h i Incrementing successively, i is a positive integer.

[0090] In the present invention, by h1, h2, ..., h iIncreasingly, when the lower wall 610 of the guide channel 605 is inclined, the pressure relief groove 601 can seal the safety valve 8, so that the cover plate 602, the pressure relief groove 601 and the safety valve 8 form a closed space. At the same time, the inclination of the lower wall 610 is conducive to the electrolyte being smoothly discharged from the guide channel 605 under the action of inertia and gravity, and further discharged into the confluence channel 606.

[0091] In some embodiments, a phase change material accommodating cavity is disposed in the convex bump 603 .

[0092] In the present invention, by providing a phase change material accommodating cavity in the convex hump 603 and filling the phase change material therein, the high-temperature gas-liquid mixed electrolyte can exchange heat with the phase change material when encountering the convex hump 603, and electrolyte droplets are formed on the surface of the convex hump 603. The droplets fall downward into the lower wall 610 of the guide channel 605 under the action of gravity and then are discharged from the guide channel 605. In the present invention, the phase change material can be a phase change material well known in the art, for example, a high-temperature phase change material molten salt, a medium-temperature phase change material hydrated salt, an organic substance or a polymer material, or a low-temperature phase change material fatty acid; other inorganic, organic, or organic and inorganic composite phase change materials with a suitable phase change conversion temperature can also be selected according to the required phase change temperature range, heat storage density, thermal conductivity, etc.

[0093] In some embodiments, the inner bottom surface 612 of the bus channel is coated with an electrolyte inhibitor.

[0094] In the present invention, by coating the electrolyte inhibitor on the inner bottom surface 612 of the confluence channel, the liquid electrolyte can be fully contacted with the electrolyte inhibitor after entering the confluence channel 606, and the corresponding chemical reaction between the electrolytes is slowed down to stop, and the release of heat is stopped. When the volume of the electrolyte in the confluence channel 606 reaches a certain amount, the electrolyte is discharged through the drain port at the bottom of the confluence channel 606. In the present invention, the electrolyte inhibitor can be an electrolyte inhibitor well known in the art, for example, it can be NaHCO3 or KHCO3, it can be one or more of tetrafluoroethane, heptafluoropropane, tetrafluoropentane, perfluoropentane, ethylenediamine or dibenzylamine, and it can also be a substance with the property of blocking C, H free radicals and combining lithium ions, or an electrolyte inhibitor with the property of combining C, H or O free radicals or inhibiting the activity of C, H or O free radicals.

[0095] In the present invention, the electrolyte inhibitor also needs to be further adaptively selected according to the composition of the electrolyte. The electrolyte generally includes an electrolyte containing lithium ions and a carbonate solvent. Well-known electrolytes in the electrolyte can be used, such as lithium salt-containing electrolytes including LiPF6, LiBF4, LiSbF6, etc.

[0096] In some embodiments, the connecting pipe 607 is connected to the explosion-proof valve 5 , and the explosion-proof valve 5 is fixedly disposed on the panel structure 4 .

[0097] In some of the embodiments, the explosion-proof valve 5 includes an explosion-proof membrane and a protective cover arranged outside the explosion-proof membrane.

[0098] In the present invention, the explosion-proof valve 5 is connected to the confluence channel 606 through the connecting pipe 607, and is used to discharge the gas in the confluence channel 606. At the same time, the connecting pipe 607 does not contact the bottom of the confluence channel 606, so as to prevent the electrolyte in the confluence channel 606 from overflowing from the connecting pipe 607. Under normal conditions, the explosion-proof valve 5 is in a closed state, preventing outside air and moisture from entering the battery module, thereby improving the protection level of the battery module. When the battery module is thermally runaway, the explosion-proof membrane of the explosion-proof valve 5 is ruptured under the action of the gas in the confluence channel 606, and the protective cover is pushed open to form an opening, thereby discharging gas to achieve the effect of pressure relief.

[0099] In another specific embodiment, the present invention provides a method for protecting a battery module that can effectively prevent the spread of thermal runaway, wherein the protection method uses the battery module that can effectively prevent the spread of thermal runaway according to the first aspect of the present invention;

[0100] The protection method comprises the following steps:

[0101] When thermal runaway occurs in the battery cell 9, the safety valve 8 of the battery cell 9 ruptures and opens, spraying a jet containing electrolyte and gas. The jet enters the pressure relief guide 6 and the electrolyte and gas are separated in the pressure relief guide 6, and then the gas and electrolyte are discharged from the battery module respectively.

[0102] In the present invention, after the battery cell 9 has thermal runaway, the safety valve 8 of the battery cell 9 first ruptures and opens, spraying out a jet containing high-temperature electrolyte and a large amount of gas, including combustible gas, and the jet enters the pressure relief and diversion assembly for separation and directionally diversion to prevent the thermal runaway from spreading.

[0103] In some embodiments, the protection method comprises the following steps:

[0104] When the battery cell 9 experiences thermal runaway, the safety valve 8 of the battery cell 9 ruptures and opens, and a jet containing electrolyte and gas is ejected. The impact force of the jet causes the cover plate 602 of the pressure relief groove 601 above the safety valve 8 to open. Due to the obstruction of the upper wall 609 of the guide channel 605 and the cover plate 602, the movement mode of the jet changes from vertically upward jetting to flowing out in the direction of the guide outlet 611.

[0105] During the process of the jet flowing out of the guide channel 605, the high-temperature gas-liquid mixed electrolyte contacts the convex hull 603 filled with phase change material in the guide channel 605, so that the temperature of the high-temperature gas-liquid mixed electrolyte decreases and forms droplets condensed on the surface of the convex hull 603. Under the action of gravity, the electrolyte drops to the lower wall 610 of the guide channel 605, thereby realizing the first separation of the electrolyte and gas in the jet;

[0106] The electrolyte flows to the guide outlet 611 under the action of inertia and gravity, and the electrolyte and gas in the guide channel 605 exert force on the movable barrier sheet 604 to open the movable barrier sheet 604 to form an opening, and the electrolyte and gas enter the converging channel 606 through the guide outlet 611 and the elbow 613;

[0107] In the confluence channel 606, the electrolyte reacts with the electrolyte inhibitor to reduce the release of heat, and then the electrolyte is discharged from the battery module from the drain port at the bottom of the confluence channel 606, and the gas is discharged from the connecting pipe 607 at the upper part of the cavity of the confluence channel 606, thereby achieving a second separation of gas and electrolyte. Under the action of the gas, the explosion-proof membrane of the explosion-proof valve 5 ruptures, and the protective cover is pushed open by the gas to form an opening, which has the effect of relieving pressure on the battery module.

[0108] The protection method provided by the present invention can separate the gas and electrolyte after the battery cell 9 sprays the valve, and discharge them in a directional manner, thereby preventing the spray from splashing disorderly and endangering other normal battery cells or modules, and preventing the battery module from spontaneous combustion or explosion.

[0109] In another specific embodiment, the present invention provides an energy storage device, wherein the energy storage device comprises the battery module capable of effectively preventing the spread of thermal runaway as described in the first aspect of the present invention.

[0110] The energy storage device provided by the present invention may be, for example, an energy storage system. By adopting the battery module provided by the present invention, the spread of thermal runaway can be effectively prevented, thereby improving the safety of the energy storage system.

[0111] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A battery module that can effectively prevent the spread of thermal runaway, characterized in that: The battery module includes an upper shell, a lower box, a battery module, a pressure relief guide, a panel structure and a CCS assembly; The upper shell and the lower box body form a accommodating cavity; At least one battery module is arranged in the accommodating cavity; The battery module includes at least one battery cell, each battery cell is connected in series, each battery cell is provided with a safety valve, and a pressure relief guide is provided above the safety valve; A panel structure is provided at one end of the battery module along the arrangement direction of the battery cells; A CCS component is arranged above the battery module.

2. The battery module according to claim 1, wherein: A heat insulation pad is provided between the side surfaces of adjacent battery cells.

3. The battery module according to claim 1 or 2, characterized in that: The pressure relief guide member includes a guide channel, a pressure relief groove, a cover plate, a convex bump, a movable barrier plate, a converging channel and a connecting pipe; Preferably, the guide channel is provided above the battery module, and includes an upper wall and a lower wall provided correspondingly. The guide channel extends from one end close to the panel structure to the other end away from the panel structure, and the vertical distance between the lower wall of the guide channel and the upper surface of the battery module gradually increases. Preferably, the diversion channel is provided with a diversion outlet at one end close to the panel structure, and the other end is sealed; Preferably, a pressure relief groove is provided on the lower wall corresponding to the position of the safety valve in the battery module; Preferably, the bottom of the pressure relief groove protrudes from the lower surface of the lower wall, the top of the pressure relief groove protrudes from the upper surface of the lower wall and does not contact the upper wall, the bottom opening of the pressure relief groove is in circumferential contact with the corresponding safety valve, and the top opening of the pressure relief groove is provided with a cover plate, and the cover plate, the pressure relief groove and the safety valve constitute a closed space; Preferably, one end of the cover plate away from the diversion outlet is fixedly connected to the pressure relief groove, and the other end is in movable contact with the pressure relief groove; Preferably, at least one convex bump is provided on the bottom surface of the upper wall of the guide channel, and the convex bump is provided between adjacent cover plates; Preferably, the movable barrier is provided in the diversion channel and is located between the diversion outlet and the first pressure relief groove close to the diversion outlet, the upper end of the movable barrier is fixedly connected to the upper wall, and the other end is in movable contact with the lower wall; Preferably, the converging channel is provided below the diversion outlet, and the diversion outlet is connected to the converging channel via a bend pipe; Preferably, a drain port is provided at the bottom of the confluence channel; Preferably, a connecting pipe is provided on the upper portion of the cavity of the confluence channel; Preferably, along the extension direction of the diversion channel, the maximum height of the first pressure relief groove protruding from the lower wall near the diversion outlet is h1, the maximum height of the second pressure relief groove protruding from the lower wall is h2, ..., the maximum height of the last pressure relief groove protruding from the lower wall is h i , the h1, h2, ..., h i Incrementing successively, i is a positive integer.

4. The battery module according to claim 3, characterized in that A phase change material accommodating cavity is provided in the convex hull.

5. The battery module according to claim 3, characterized in that: The inner bottom surface of the confluence channel is coated with an electrolyte inhibitor.

6. The battery module according to claim 3, characterized in that The connecting pipe is communicated with an explosion-proof valve, and the explosion-proof valve is fixedly arranged on the panel structure.

7. The battery module according to claim 6, characterized in that The explosion-proof valve comprises an explosion-proof membrane and a protective cover arranged on the outside of the explosion-proof membrane.

8. A method for protecting a battery module that can effectively prevent the spread of thermal runaway, characterized in that: The protection method adopts the battery module capable of effectively preventing the spread of thermal runaway as described in any one of claims 1 to 7; The protection method comprises the following steps: When a battery cell experiences thermal runaway, the safety valve of the battery cell ruptures and opens, spraying a jet containing electrolyte and gas. The jet enters the pressure relief guide and separates the electrolyte and gas inside the pressure relief guide, and then the gas and electrolyte are discharged from the battery module separately.

9. The protection method according to claim 8, characterized in that: The protection method comprises the following steps: When a battery cell experiences thermal runaway, the safety valve of the battery cell ruptures and opens, spewing out a jet containing electrolyte and gas. The impact of the jet causes the cover of the pressure relief groove above the safety valve to open. Due to the obstruction of the upper wall and cover of the diversion channel, the movement of the jet changes from vertical upward spraying to flowing out toward the diversion outlet. During the outflow of the jet in the guide channel, the high-temperature gas-liquid mixed electrolyte contacts the convex hull filled with the phase change material in the guide channel, causing the temperature of the high-temperature gas-liquid mixed electrolyte to decrease and form droplets that condense on the surface of the convex hull. Under the action of gravity, the electrolyte drips onto the lower wall of the guide channel, thereby achieving the first separation of the electrolyte and gas in the jet; The electrolyte flows to the diversion outlet under the action of inertia and gravity. The electrolyte and gas in the diversion channel exert force on the movable barrier plate to open the movable barrier plate to form an opening. The electrolyte and gas enter the converging channel through the diversion outlet and the elbow. In the bus channel, the electrolyte reacts with the electrolyte inhibitor to reduce the release of heat. Then the electrolyte is discharged from the battery module from the drain port at the bottom of the bus channel, and the gas is discharged from the connecting pipe at the upper part of the bus channel cavity, thereby achieving a second separation of gas and electrolyte. Under the action of the gas, the explosion-proof membrane of the explosion-proof valve ruptures, and the protective cover is pushed open by the gas to form an opening, which serves to relieve the pressure on the battery module.

10. An energy storage device, characterized in that: The energy storage device contains the battery module according to any one of claims 1 to 7 that can effectively prevent the spread of thermal runaway.

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