Battery module, battery pack and electric equipment

Abstract

The utility model provides a battery module, a battery pack and electric equipment. The battery module comprises a plurality of battery cell frames and battery cells arranged in the battery cell frames, the first cavity is arranged between the to-be-blocked side of the battery cell and the battery cell frame; and the first flame-retardant part is formed by an intumescent flame-retardant material and is arranged in the first cavity, the first flame-retardant part is heated to expand to form a blocking part for blocking the first cavity, and the blocking part is used for guiding jetted matter which is out of control after being heated in the battery cell to be discharged from one side of the battery cell which is not blocked by the blocking part. According to the technical scheme, thermal runaway gas guiding is effectively achieved, the structural complexity and the design and assembly difficulty are reduced, and meanwhile the energy density can be improved.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the technical field of battery thermal runaway protection, and more specifically, to a battery module, a battery pack, and an electrical device. Background Art

[0002] The current mainstream thermal runaway protection solutions for soft-pack battery modules mostly add passive insulation materials such as module structural parts, horizontal and vertical beams, and protective plates between the cells. Pressure is applied to the bottom and top of the cells through temperature-resistant and fire-proof structural parts. When the cell thermally runs away, the air and pressure are released from the top seal of the soft-pack battery cell.

[0003] The pack-level thermal runaway protection of the soft-pack battery system uses the horizontal and vertical beams inside the box and insulating materials such as protective plates as barriers to prevent high-temperature and high-speed gases from being transmitted to other areas / modules after thermal runaway.

[0004] However, the protection structure at the battery module level, the module structural parts, the internal horizontal and vertical beams, the insulation materials such as the protective plates, are fixed in structure relative to the pressure relief channel. The complex structure increases the difficulty of design and assembly, while also increasing the overall mass of the module, affecting the energy density. In addition, the battery module is close to bus components such as the electrical connection copper busbar. After thermal runaway occurs, the high-temperature and high-speed gas generated may carry conductive dust and adhere to the copper busbars connected to the high voltage, causing an external short circuit and further causing heat diffusion of the entire package.

[0005] The pack-level protection structure is the box body and the internal horizontal and vertical beams, protective plates and other insulating materials. The structure is fixed relative to the pressure relief channel, and there are incomplete seals between the horizontal and vertical beams and the upper cover between the various areas or modules of the box body. There is a situation where the high-temperature and high-speed gas generated after thermal runaway occurs moves between the various areas or modules, causing heat diffusion of the entire package. If the connection between the cavities is completely closed, the modules will not be able to be electrically connected and managed (including high and low voltage wiring harnesses), and increasing the height of the horizontal and vertical beams will increase the weight of the box and sacrifice a certain amount of energy density. Utility Model Content

[0006] In order to solve or partially solve the above-mentioned defects, according to the embodiments of the present invention, a battery module, a battery pack and an electrical device are provided to effectively realize the thermal runaway gas guidance in the module level and the pack level, reduce the structural complexity and the difficulty of design and assembly, and improve the energy density.

[0007] In a first aspect of the present disclosure, a battery module is provided. The battery module comprises:

[0008] A plurality of battery cell frames, and battery cells arranged in the battery cell frames;

[0009] Also includes:

[0010] A first cavity is provided between the side of the battery cell to be blocked and the battery cell frame;

[0011] The first flame retardant portion is formed of an expandable flame retardant material and is disposed in the first cavity. The first flame retardant portion expands when heated to form a blocking portion for blocking the first cavity. The blocking portion is used to guide the jet of thermal runaway in the battery cell to escape from a side of the battery cell that is not blocked by the blocking portion.

[0012] According to the above aspects and any possible implementation, there is further provided an implementation, wherein the volume of the first flame retardant portion when not thermally expanded is 40% to 60% of the volume of the first cavity;

[0013] The volume of the first flame retardant portion after thermal expansion is 110% to 130% of the volume of the first cavity.

[0014] According to the above aspects and any possible implementation, there is further provided an implementation, wherein the intumescent flame retardant material is an intumescent flame retardant colloid, the volume expansion rate of which is greater than 200%, and the viscosity η is 800cps≤η≤1200cps; and / or,

[0015] Along the height direction of the battery core, the side sealing portion with smaller packaging strength is located at the top, and the extrusion force generated by the first flame retardant portion after thermal expansion is 1 to 3 times the packaging force of the side sealing portion located at the top.

[0016] According to the above aspects and any possible implementation manner, an implementation manner is further provided, wherein the battery cell comprises two top sealing portions, one of the two top sealing portions is disposed at one end of the battery cell along the length direction thereof, and the other of the two top sealing portions is disposed at the other end of the battery cell along the length direction thereof;

[0017] The first cavity is formed between the cell frame and the top sealing portion.

[0018] According to the above aspects and any possible implementation manner, an implementation manner is further provided, wherein there are two first cavities, and at least one of the two first cavities is provided with the first flame-retardant portion.

[0019] According to the above aspects and any possible implementation manner, an implementation manner is further provided, wherein the battery cell comprises two side sealing portions, one of the two side sealing portions is arranged at one end of the battery cell along the height direction thereof, and the other of the two side sealing portions is arranged at the other end of the battery cell along the height direction thereof;

[0020] The first cavity is formed between the cell frame and the side sealing portion.

[0021] According to the above aspects and any possible implementation manner, an implementation manner is further provided, wherein there are two first cavities, and at least one of the two first cavities is provided with the first flame-retardant portion.

[0022] In a second aspect of the present disclosure, a battery pack is provided. The battery pack comprises:

[0023] A box body, in which a plurality of battery modules according to the first aspect of the present disclosure are arranged;

[0024] A box cover is assembled on the open side of the box body to close it.

[0025] According to the aspects described above and any possible implementation method, an implementation method is further provided, wherein a second cavity is provided between the box cover and the battery module, and along the extension direction of the battery cell frame, a plurality of rubber strips formed of expandable flame retardant material are extended on the inner side surface of the box cover close to the battery module, and the plurality of rubber strips form a second flame retardant portion.

[0026] According to the above aspects and any possible implementation, there is further provided an implementation, when not thermally expanded, the thickness of the rubber strip along the direction from the top of the battery module to the box cover is 40% to 60% of the distance between the two;

[0027] After thermal expansion, the unoccupied volume of the second cavity between two adjacent rubber strips is equal to or slightly larger than the total gas generation of the battery cell between the two adjacent rubber strips.

[0028] According to the above aspects and any possible implementation, an implementation is further provided, wherein a beam is arranged between the battery modules to separate the battery modules, a third cavity is provided between the beam and the box cover, and a reserved groove is formed at the end of the beam opposite to the box cover, a third flame retardant portion formed of an intumescent flame retardant material is provided in the reserved groove, and the third flame retardant portion expands when heated to block the third cavity; and / or,

[0029] An explosion-proof valve is arranged on the side wall of the box body, and the ejected material from the battery cell is guided by the blocking portion to be discharged from the explosion-proof valve to the outside.

[0030] In a third aspect of the present disclosure, an electric device is provided, which includes: the battery module as described in the first aspect of the present disclosure or the battery pack as described in the second aspect of the present disclosure.

[0031] The battery module, battery pack and electrical equipment provided by the present disclosure, relative to setting up a heat-conducting structural member, can actively establish a directional pressure relief path for the gas by using the expandable flame-retardant material of the first flame-retardant portion set in the first cavity, thereby effectively achieving the diversion of thermal runaway gas at the battery module level.

[0032] Furthermore, by relying on the second and third flame retardant parts of the intumescent flame retardant material arranged in the second and third cavities, a directional pressure relief path for the gas is actively established, thereby effectively achieving the diversion of the thermal runaway gas in the battery pack level. There is no need to consider using high-weight metal parts or fireproof materials to design the heat-conducting structure, which is conducive to lightweighting and improving energy density while reducing the difficulty of design and assembly.

[0033] In addition, a first cavity can be formed between the battery cell frame and the battery cell top seal, and the top seal position relative to the battery cell and the bus can be sealed by the first flame retardant part at high temperature to prevent high-temperature gas carrying conductive graphite from being sprayed onto the bus side and to avoid external short circuit caused by the connection between the bus bars.

[0034] It should be understood that the contents described in the disclosure section are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other features, advantages and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

[0036] Figure 1 A schematic structural diagram of a battery pack provided in an embodiment of the present disclosure is shown;

[0037] Figure 2 A schematic structural diagram of a battery module provided in an embodiment of the present disclosure is shown;

[0038] Figure 3 for Figure 2 Schematic diagram of the structure of local A in ;

[0039] Figure 4 A schematic diagram of the structure of the battery cell and the battery cell frame assembly provided in an embodiment of the present disclosure is shown;

[0040] Figure 5 A schematic diagram of a top view of the assembly of a battery cell and a battery cell frame provided in an embodiment of the present disclosure is shown;

[0041] Figure 6 A schematic cross-sectional view of a battery pack provided by an embodiment of the present disclosure is shown;

[0042] Figure 7 Shows Figure 6 A partially enlarged cross-sectional view of a battery pack provided in the embodiment.

[0043] in, Figures 1 to 7 The corresponding relationship between the reference numerals and component names in the figure is:

[0044] 100 battery pack, 110 box body, 120 box cover, 121 second flame retardant part, 130 beam frame, 131 reserved groove, 140 second cavity, 150 third cavity, 160 explosion-proof valve;

[0045] 200 battery module, 210 battery cell frame, 211 fixing piece, 220 battery cell, 221 top sealing part, 222 side sealing part, 230 first cavity. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0047] In addition, the term "and / or" in this article is only a description of the association relationship between the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0048] In the present disclosure, a battery module, a battery pack and an electrical device are provided, which can be used for thermal runaway diversion of soft-pack batteries. The design is simple and reliable, and the production and assembly are convenient. In addition, the diversion structure is light in weight, which is conducive to improving the energy density.

[0049] Refer to the following Figures 1 to 7 To describe the battery module, battery pack and electrical equipment provided by the embodiments of the present disclosure.

[0050] Figure 1 1 shows a schematic structural diagram of a battery pack 100 provided in an embodiment of the present disclosure, as shown in FIG. Figure 1 As shown, a battery pack 100 provided according to an embodiment of the present disclosure includes a plurality of battery modules 200 , a box body 110 carrying the plurality of battery modules 200 , a box cover 120 assembled with the box body 110 , and a beam frame 130 separating the battery modules 200 .

[0051] Among them, the battery module 200 is as follows Figure 2 The schematic diagram of the structure of the battery module 200 provided in the embodiment of the present disclosure is shown. The battery module 200 provided in the embodiment of the present disclosure includes a plurality of battery cell frames 210 and battery cells 220 disposed in the battery cell frames 210.

[0052] The cell frame 210 includes plastic fixings 211 at both ends and a heat conducting plate disposed in the middle of the fixings 211. The heat conducting plate is made of aluminum. The cell frame 210 is disposed longitudinally in the battery module 200. In this embodiment, the cell 220 is a soft-pack cell. Figure 4 , 5 As shown, top seals 221 are formed at both ends of the length direction of the battery cell 220 and side seals 222 are formed at both ends of the height direction of the battery cell 220. Multiple battery cell frames 210 carry the battery cells 220 and are stacked in a direction perpendicular to the plane of the battery cells 220. End plates and side plates are arranged on the outside of the stacked module. The structure composed of two adjacent battery cell frames 210 and battery cells 220 is separated by a heat insulating member, which is set as fireproof and heat insulating foam. A pre-tightening force of 30kN is applied along the stacking direction of the battery cell frames 210 to fix the battery cell stack as a whole, so that there is a strong pressing force in the stacking direction. Thus, the fireproof insulation foam is used to isolate the heat and gas between each battery cell 220 and / or the heat is dissipated to the outside and the gas is isolated by the heat conductive plate, so as to prevent the gas and heat generated by the thermal runaway of the battery cell 220 from being directly transferred to the adjacent battery cell 220. In addition, the strong clamping force in the stacking direction can be combined to prevent the pressure release direction of the battery cell 220 in the stacking direction after gas generation, so as to control the impact of thermal runaway to a smaller range as much as possible.

[0053] It should be noted here that the length direction of the battery cell 220 is consistent with the length direction of the battery module, and the height direction of the battery cell 220 is consistent with the height direction of the battery module.

[0054] Preferably, the cell frame 210 is configured as a C-shaped frame. The cell frame 210 of the present disclosure can be configured as a cell frame of any structure currently used for soft-pack cells, which is not limited here, for example, it can also be configured as an I-shaped frame. Each battery module 200 can also be configured according to an existing cell module structure.

[0055] The battery cell 220 includes two top seals 221, one of which is disposed at one end of the battery cell 220 along its length direction, and the other of which is disposed at the other end of the battery cell 220 along its length direction; the battery cell 220 includes two side seals 222, one of which is disposed at one end of the battery cell 220 along its height direction, and the other of which is disposed at the other end of the battery cell 220 along its height direction. In addition, in the present embodiment, in the battery cell frame 210, along the height direction of the battery cell 220, the side seal 222 of the battery cell 220 with relatively small packaging strength is located at the top, and the side seal 222 of the battery cell 220 with relatively large packaging strength is located at the bottom.

[0056] A first cavity 230 is provided between the side to be blocked of the battery cell 220 and the battery cell frame 210. The side to be blocked of the battery cell 220 can be determined according to the position of the battery cell tabs and the busbars. For example, if the battery cell tabs and the busbars are arranged corresponding to the top sealing portion 221 at one end of the battery cell 220, then the side to be blocked of the battery cell 220 is the end corresponding to the battery cell tabs and the busbars. If the battery cell tabs and the busbars are arranged at both ends of the battery cell 220, then the side to be blocked of the battery cell 220 is the corresponding two ends, so as to avoid the thermal runaway ejection from contacting the battery cell tabs and the busbars to cause a short circuit. Alternatively, one or more sides of the battery cell 220 can be blocked according to the actual structural requirements, and at most three sides can be blocked, leaving an unblocked side for the thermal runaway ejection to escape.

[0057] Further, the first cavity 230 is formed between the cell frame 210 and the top seal portion 221. There are two first cavities 230, and at least one of the two first cavities 230 is provided with the first flame retardant portion. Specifically, in this embodiment, the first cavity 230 is formed between the two top seal portions 221 at opposite ends of the length direction of the cell 220 and the cell frame 210, and the two first cavities 230 opposite to each other are formed on the inner side of the cell frame 210, such as Figure 3 shown Figure 2 The schematic diagram of the structure of the local A in Figure 4 , 5 The schematic diagram of the structure of the battery cell 220 and the battery cell frame 210 is shown, which indicates the position of the first cavity 230. Further, the size of the battery cell frame 210 is set to reserve a specified distance between the fixing members 211 at both ends of the battery cell frame 210 and the top sealing parts 221 at both ends of the battery cell 220 in the length direction, thereby forming the first cavities 230 located at the top sealing parts 221 at both ends of the battery cell 220.

[0058] A first flame retardant portion is arranged in the first cavity 230. The first flame retardant portion adopts an expandable flame retardant material. The expandable flame retardant material has the characteristics of rapid expansion when encountering high temperature / open flame, having a flame retardant effect on flames and a stable expansion rate. Under the condition of controlling the dosage, a stable isolation gas barrier can be provided and a channel can be formed. The material expands when encountering heat so that the high-temperature gas can only move along the direction of the channel formed by the material.

[0059] In the present embodiment, the first cavity 230 is formed at the top sealing portion 221 at both ends of the battery cell 220. When the battery cell thermally runs away and high-temperature gas is discharged, the first flame retardant portion expands rapidly when heated to seal the top sealing portion 221 at both ends of the battery cell 220, thereby forming a plugging portion and forming a first pressure relief path to guide the gas in the height direction of the battery cell 220, and transferring the high-temperature gas and heat in a directional manner in the upward and downward directions through the heat-conducting aluminum plate, thereby preventing the high-temperature gas from carrying conductive graphite and other materials and spraying out to the side of the bus formed on the outside of the fixings 211 at both ends of the battery cell frame 210, thereby avoiding external short circuits caused by connections between the bus bars. In addition, the side seal part 222 of the battery cell 220 located at the bottom has a large packaging strength and is placed on the bottom plate of the box body 110 to be under pressure, while the side seal part 222 located at the top has a small packaging strength, and there is a certain space with low pressure between the battery module 200 and the upper box cover 120 to facilitate pressure relief, so that the high-temperature and high-speed gas generated by thermal runaway is preferably ejected from the side seal part 222 of the battery cell 220 located at the top with small packaging strength, and flows upward after being ejected, or even after being ejected from any position of the battery cell 220, it will flow upward to impact and destroy the battery cell frame 210, and diffuse disorderly above the battery cell frame 210.

[0060] Furthermore, in the present embodiment, the first flame retardant part adopts an expandable flame retardant colloid, which is filled in the first cavity 230 formed between the top sealing part 221 of the battery cell 220 and the fixing part 211 of the battery cell frame 210. The amount of colloid used is: the volume of the colloid after thermal expansion is 110% to 130% of the volume of the first cavity 230, preferably, it is 120% of the volume of the first cavity 230. After the expansion is completed, it can be ensured that the first cavity 230 is completely sealed and has a certain extrusion pressure. The magnitude of the extrusion pressure can refer to the bearing capacity of the aluminum-plastic film of the top sealing of the battery cell 220 and the plastic fixing part 211 of the battery cell frame 210. For example, the extrusion pressure generated by the thermal expansion of the colloid is selected to be 1 to 3 times the packaging force of the side sealing part 222 with smaller packaging strength located above. Preferably, the extrusion pressure is selected to be 120N / 15mm, which is the position The packaging force of the upper side sealing part 222 is twice that of the side sealing part 222, so that the first pressure relief path after the battery cell 220 has thermal runaway is upwardly facing the box cover 120; preferably, a glue with a volume expansion rate of more than 200% is used, and the viscosity η should be 800cps≤η≤1200cps; the volume of the first flame retardant part when not thermally expanded is 40% to 60% of the volume of the first cavity 230. Preferably, 50% of the cavity volume of the first cavity is filled during module production and assembly, thereby minimizing the amount of glue used during module assembly and ensuring that the remaining cavity volume is as small as possible, so that the cavity can be quickly sealed when thermal runaway occurs.

[0061] It should be noted here that "packaging force" refers to the force required for the packaged part, such as the packaging part, to be broken open or ruptured.

[0062] The intumescent flame retardant colloid preferably adopts epoxy intumescent flame retardant material, and may also adopt polyurethane and silicon-based flame retardant materials.

[0063] Thus, at the battery module level, when high-temperature gas is discharged, the first flame-retardant portion formed of the intumescent flame-retardant material and disposed in the first cavity 230 expands due to heat to form a blocking portion for blocking the first cavity 230, and the blocking portion is used to guide the jet of thermal runaway in the battery cell 220 to escape from the side of the battery cell 220 that is not blocked by the blocking portion, thereby forming a first pressure relief path for diversion, such as Figure 4 The arrows in the figure indicate the direction. Since the sealing portion formed by the first flame retardant portion seals the two top sealing portions 221 of the battery cell 220, and has fireproof insulation foam and / or heat conductive plates in the stacking direction and is under pressure, and the side sealing portion 222 of the battery cell 220 located below has high packaging strength and is placed on the bottom plate of the box body 110 under pressure, and there is a certain space between the battery module 200 and the upper box cover 120 to release pressure, the high-temperature and high-speed gas generated by thermal runaway flows along the first pressure relief path, that is, flows upward to impact and destroy the battery cell frame 210, and diffuses disorderly above the battery cell frame 210.

[0064] The battery pack provided by the present disclosure has a plurality of battery modules 200 as described above disposed inside the box 110. In this embodiment, Figure 1 As shown, four battery modules 200 are arranged in two rows. The box cover 120 is assembled on the open side of the box body 110 to close it. In this embodiment, the upper end of the box body 110 is open, and the box cover 120 is arranged on the upper end of the box body 110. A plurality of explosion-proof valves 160 are arranged on the side walls corresponding to the two ends of the battery cell frame 210 on both sides of the box body 110. The ejected material from the battery cell 220 is guided by the blocking part to be discharged from the explosion-proof valve 160 to the outside. A beam frame 130 is arranged between the battery modules 200 to separate each battery module 200.

[0065] Figure 6 A schematic cross-sectional view of a battery pack 100 provided in an embodiment of the present disclosure is shown along a cross section parallel to a stacking direction of a battery module 200; Figure 7 Shows Figure 6 The embodiment of the present invention provides a partial enlarged cross-sectional view of the battery pack 100. Figure 6 , 7As shown, there is a second cavity 140 between the box cover 120 and the battery module 200, and a second flame retardant part 121 is arranged along the inner side of the box cover 120 close to the battery module 200. The second flame retardant part 121 has a plurality of rubber strips parallel to the extension direction of the battery cell frame 210, that is, a plurality of rubber strips are extended and arranged on the inner side of the box cover 120 along a direction perpendicular to the stacking direction of the battery cell frame 210, and the rubber strips are also made of intumescent flame retardant material. When any battery cell 220 in the battery module 200 generates thermal runaway, and the high-temperature gas contacts the second flame retardant part 121, the second flame retardant part 121 expands due to heat, blocks the second cavity 140 between the box cover 120 and the battery module 200 where the high-temperature gas is generated in the height direction, isolates the battery cell 220 in thermal runaway, controls the impact of thermal runaway within a smaller range as much as possible, reduces the number of affected battery cells 220, avoids the high-temperature gas from diffusing and transmitting to a large range, and forms a second pressure relief path along the extension direction of the second flame retardant part 121.

[0066] The rubber strip uses a semicircular mold to control the curing and forming of the colloid on the upper cover. The curing and forming height is when the rubber strip is not expanded by heat, and the thickness of the rubber strip along the direction from the top of the battery module 200 to the box cover 120 is 40% to 60% of the distance between the two. Preferably, it is 50% of the distance between the top of the battery module 200 and the box cover 120. In this way, the amount of glue used during module assembly can be minimized, and the remaining cavity volume can be kept as small as possible, so that the cavity can be quickly closed when thermal runaway occurs.

[0067] In addition, the rubber strips are arranged according to the number of battery cells 220, and the unoccupied volume of the second cavity 140 between two adjacent rubber strips after thermal expansion is equal to or slightly greater than the total gas production of the battery cells between the two adjacent rubber strips, that is, the spacing between two adjacent rubber strips is arranged so that the remaining cavity volume between the two rubber strips after the rubber strips expand is equal to or slightly greater than the total gas production of the battery cells within the spacing between the two rubber strips. Specifically, the total gas production L1 is calculated according to the number of battery cells 220 within the spacing, and the remaining cavity volume L2 between the two rubber strips after thermal expansion is obtained according to the volume of the rubber strips and the thermal expansion rate of the colloid, so that L1=L2, ensuring that the pressure in the battery pack 100 is controllable, and at the same time there is enough space to slow down the flow rate of high-speed gas and reduce impact.

[0068] The beam frame 130 is arranged between the battery modules 200 to separate each battery module 200. In this embodiment, the beam frame 130 is a cross-shaped horizontal and vertical beam, and the bottom end of the beam frame 130 is welded to the bottom plate of the box body 110. There is a third cavity 150 between the beam frame 130 and the box cover 120, and a reserved groove 131 is formed at the ends opposite to the box cover 120. A third flame retardant portion is arranged in the reserved groove 131, and the third flame retardant portion adopts an intumescent flame retardant material. The intumescent flame retardant colloid is coated / filled in the reserved groove 131 to block the third cavity 150 between the box cover 120 and the beam frame 130 to prevent the high-temperature gas from being transmitted to the adjacent modules. The height design of the beam 130 can be coordinated with the amount of colloid used. In principle, it needs to fill the space between the beam 130 and the box cover 120 after expansion. For lightweight considerations, the design height of the beam 130 can be reduced as much as possible while ensuring the pack mode of the battery pack, and the third cavity 150 between the beam 130 and the box cover 120 can be sealed by the expansion of the colloid.

[0069] Thus, for a battery module 200, its periphery is surrounded by the beam frame 130 and the side wall of the box body 110, the upper end of the beam frame 130 is provided with a third flame retardant part, and the box cover 120 above the battery module 200 is formed with a plurality of rubber strips along the extension direction of the battery cell frame 210, constituting a second flame retardant part. The rubber strips can be arranged to extend from the corresponding position of the beam frame 130 to the edge of the box cover 120, or can be arranged to extend from one side edge of the box cover 120 to the other side edge of the box cover 120, and the third flame retardant part can seal the cavity between adjacent battery modules 200 after being heated and expanded.

[0070] When the high-temperature gas from the first pressure relief path contacts the second flame retardant part 121 and the third flame retardant part, the second flame retardant part and the third flame retardant part expand due to the heat, blocking the second cavity 140 and the third cavity 150 where the high-temperature gas is generated, isolating the battery cell with thermal runaway, and forming a second pressure relief path between the two rubber strips of the second flame retardant part 121 or between the second flame retardant part 121 and the third flame retardant part, so that the second pressure relief path is formed along the extension direction of the rubber strip of the second flame retardant part 121. The high-temperature gas diffused from the battery cell 220 passes through the first pressure relief path formed between the first flame retardant parts, and then passes through the second pressure relief path along the extension direction of the second flame retardant part, and then flows to the side wall of the box body 110 and is discharged outward through the explosion-proof valve 160.

[0071] Figure 7The pressure relief path is shown, the dotted arrow indicates the flow direction of the thermal runaway gas, the solid arrow indicates the expansion direction of the flame retardant part, and the curved arrow indicates the direction of the thermal runaway gas turning when encountering resistance. The position of the explosion-proof valve 160 in the figure is only a schematic representation of the pressure relief path. It can be seen that at the battery pack 100 level, when any battery cell 220 in the battery module 200 produces thermal runaway, the high-temperature and high-speed gas passes through the first section of the pressure relief path and contacts the second flame retardant part solidified on the box cover 120. The second flame retardant part 121 is heated and expanded downward, blocking the second cavity 140 between the box cover 120 and the battery module 200 where the high-temperature gas is generated; when the high-temperature gas contacts the third flame retardant part, the third flame retardant part is heated and expanded upward, blocking the third cavity 150 between the box cover 120 and the beam 130, isolating the battery cell 220 in thermal runaway. Thus, the high-temperature and high-speed gas diffused above the cell frame 210 after passing through the first section of the pressure relief path is diverted by the second flame-retardant part 121, and is blocked between the local second flame-retardant parts 121, or is blocked by the third flame-retardant part and turns back when encountering resistance between the second flame-retardant part 121 and the third flame-retardant part, so that the thermal runaway gas is controlled between the adjacent second flame-retardant parts 121 and / or between the adjacent second flame-retardant part 121 and the third flame-retardant part and guided to the adjacent explosion-proof valve 160 side, so that the high-temperature and high-speed gas is guided to the explosion-proof valve 160 on the side wall of the box body 110 for discharge. Thus, as Figure 7 As shown, the thermal runaway gases at the two end regions of the battery module 200 are isolated and will not be transferred to the middle region of the adjacent battery module 200 and other adjacent battery modules 200 .

[0072] The present disclosure also provides an electric device, in which the battery module or the battery pack as described above is arranged. It should be noted that the electric device may specifically be a new energy vehicle, an energy storage device, and the like.

[0073] In addition, optionally, in some other embodiments, the position of the first cavity can be set according to the actual module composition, the arrangement of the cell tabs and the busbars. For example, if the cell tabs and the busbars are arranged on the fixing member 211 at one end of the cell frame 210, a first cavity 230 can be formed between the top seal 221 at the opposite end and the cell frame 210, and the first cavity 230 is one to set the first flame retardant part, or the first cavity 230 is two, and the first flame retardant part is set in one of the two first cavities 230 that is opposite to the cell tabs and the busbars.

[0074] Optionally, in some other embodiments, the first cavity 230 may also be formed between the cell frame 210 and the side seals 222 on both sides of the cell 220. For example, the first cavity 230 is formed between the cell frame 210 and one or two side seals of the cell 220, and between the top seal 221 at the opposite end of the cell tab and the bus bar and the cell frame 210, so that the first flame retardant portion is heated to seal the first cavity 230, forming a pressure relief path for guiding gas in the length direction of the cell 220, and relieving pressure at the top seal 221 at the opposite end of the cell tab and the bus bar. The box cover 120 and the second flame retardant portion 121 can be adaptively arranged on the side of the box body 110.

[0075] Thus, in this embodiment, the first cavity 230 is formed between the cell frame 210 and the top seal portion 221, and one or two first cavities 230 may be formed. When there are two first cavities 230 formed at the top seal portion 221, at least one of the two first cavities 230 is provided with the first flame retardant portion. The first cavity 230 may also be formed between the cell frame 210 and the side seal portion 222. When there are two first cavities 230 formed at the side seal portion 222, at least one of the two first cavities 230 is provided with the first flame retardant portion. Furthermore, according to the actual module composition, the battery cell tabs, and the busbar settings, a first cavity 230 can be set on the side of the battery cell 220 to be sealed, and a first flame retardant portion formed of an expandable flame retardant material is arranged in the first cavity 230 to form a sealing portion when heated. The thermal runaway jet leaked from the battery cell 220 flows to the unsealed side of the battery cell 220 for pressure relief, and then is guided by the second flame retardant portion 121 and the third flame retardant portion to relieve pressure toward the explosion-proof valve 160.

[0076] According to the embodiments of the present disclosure, the following technical effects are achieved:

[0077] The battery module, battery pack and electrical equipment provided by the present invention, relative to setting up heat-conducting structural parts, can actively establish a directional pressure relief path for gas by relying on the first flame-retardant part intumescent flame-retardant material set in the first cavity 230, so as to effectively realize the diversion of thermal runaway gas in the battery module level, and rely on the second flame-retardant part intumescent flame-retardant material and the third flame-retardant part intumescent flame-retardant material set in the second cavity 140 and the third cavity 150 respectively to actively establish a directional pressure relief path for gas, so as to effectively realize the diversion of thermal runaway gas in the battery pack level, without considering the use of heavy metal parts or fireproof materials to design heat-conducting structures, which is conducive to lightweighting and improving energy density while reducing the difficulty of design and assembly.

[0078] In addition, the first cavity 230 can be formed between the battery cell frame 210 and the top sealing portion 221 of the battery cell 220, and the top sealing portion 221 of the battery cell 220 opposite to the bus can be sealed by the first flame retardant portion at high temperature to prevent high-temperature gas carrying conductive graphite and other materials from being sprayed onto the bus from the side, thereby avoiding external short circuits caused by connections between the bus bars.

[0079] In the description of this specification, the terms "connection", "installation", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0080] In the description of this specification, the description of the terms "one embodiment", "some embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0081] The above are only preferred implementations of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A battery module, characterized in that: include: A plurality of battery cell frames, and battery cells arranged in the battery cell frames; Also includes: A first cavity is provided between the side of the battery cell to be blocked and the battery cell frame; The first flame retardant portion is formed of an expandable flame retardant material and is disposed in the first cavity. The first flame retardant portion expands when heated to form a blocking portion for blocking the first cavity. The blocking portion is used to guide the jet of thermal runaway in the battery cell to escape from a side of the battery cell that is not blocked by the blocking portion.

2. The battery module according to claim 1, characterized in that: The volume of the first flame retardant portion when not thermally expanded is 40% to 60% of the volume of the first cavity; The volume of the first flame retardant portion after thermal expansion is 110% to 130% of the volume of the first cavity.

3. The battery module according to claim 1, characterized in that: The intumescent flame retardant material is an intumescent flame retardant colloid, the volume expansion rate of which is above 200%, and the viscosity η is 800cps≤η≤ 1200cps; and / or, Along the height direction of the battery core, the side sealing portion with smaller packaging strength is located at the top, and the extrusion force generated by the first flame retardant portion after thermal expansion is 1 to 3 times the packaging force of the side sealing portion located at the top.

4. The battery module according to any one of claims 1 to 3, characterized in that: The battery cell comprises two top sealing parts, one of the two top sealing parts is arranged at one end of the battery cell along the length direction thereof, and the other of the two top sealing parts is arranged at the other end of the battery cell along the length direction thereof; The first cavity is formed between the cell frame and the top sealing portion.

5. The battery module according to claim 4, characterized in that: There are two first cavities, and at least one of the two first cavities is provided with the first flame-retardant portion.

6. The battery module according to any one of claims 1 to 3, characterized in that: The battery cell comprises two side sealing parts, one of the two side sealing parts is arranged at one end of the battery cell along the height direction thereof, and the other of the two side sealing parts is arranged at the other end of the battery cell along the height direction thereof; The first cavity is formed between the cell frame and the side sealing portion.

7. A battery pack, characterized in that: include: A box body, wherein a plurality of battery modules according to any one of claims 1 to 6 are arranged inside; A box cover is assembled on the open side of the box body to close it.

8. The battery pack according to claim 7, characterized in that: A second cavity is provided between the box cover and the battery module, and a plurality of rubber strips formed of an expandable flame retardant material are extended from the inner side surface of the box cover close to the battery module along the extension direction of the battery cell frame, and the plurality of rubber strips form a second flame retardant portion.

9. The battery pack according to claim 8, characterized in that: When not expanded by heat, the thickness of the rubber strip along the direction from the top of the battery module to the box cover is 40% to 60% of the distance between the two; After thermal expansion, the unoccupied volume of the second cavity between two adjacent rubber strips is equal to or slightly larger than the total gas generation of the battery cell between the two adjacent rubber strips.

10. The battery pack according to claim 7, characterized in that: Also includes: A beam frame is arranged between the battery modules to separate the battery modules, a third cavity is provided between the beam frame and the box cover, and a reserved groove is formed at the end of the beam frame opposite to the box cover, a third flame retardant portion formed of an intumescent flame retardant material is arranged in the reserved groove, and the third flame retardant portion expands when heated to block the third cavity; and / or, An explosion-proof valve is arranged on the side wall of the box body, and the ejected material from the battery cell is guided by the blocking portion to be discharged from the explosion-proof valve to the outside.

11. An electrical device, characterized in that: include: A battery module as claimed in any one of claims 1 to 6 or a battery pack as claimed in any one of claims 7 to 10.

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