Battery pack

Abstract

Battery pack comprising at least two battery modules, each of the battery modules comprising a housing and a plurality of battery cells arranged in the housing, and wherein a side face of the housing is provided with a plurality of pressure relief holes, and wherein the plurality of pressure relief holes corresponds one-to-one to the plurality of battery cells, and wherein one end of each of the battery cells has an explosion-proof hole connected to the corresponding pressure relief hole, and wherein two adjacent battery modules form a module component, and wherein in the same module component two housings are arranged at a distance from each other to form a pressure relief passage, and wherein the pressure relief holes on the two housings each face the pressure relief passage.

Description

The present application claims priority to and the entire contents of Chinese Patent Application No. 202410166791.9, filed on Feb. 5, 2024, in the Chinese Patent Office, are incorporated herein by reference.The present application claims priority to and the entire contents of Chinese Patent Application filed on Feb. 5, 2024 in the Chinese Patent Office having Application No. 202420281382.9, which is hereby incorporated by reference.TECHNICAL FIELDThe present application relates to the technical field of the power battery, particularly to a battery pack.PRIOR ARTAt present, the new energy vehicle industry is rapidly developing, and the battery pack as an energy storage for the new energy vehicle has an energy density index that plays a decisive role for the battery duration of the new energy vehicles.DISCLOSURE OF THE APPLICATIONTechnical ProblemIn the related technology, a battery pack is usually constructed as a double layer module structure or a multi layer module structure, i.e., the battery pack includes two or more battery modules arranged in a stacked manner. This structure helps to improve the space utilization of the new energy vehicle to increase the electrical energy storage capacity of the battery pack within the limited space in the chassis. However, since the battery modules are stacked on top of each other, thermal diffusion accident may occur in a case where a thermal runaway occurs in one of the battery modules, in which substances such as high temperature gases and electrolyte are ejected, which is likely to damage other battery cells and parts in the environment and impair the safe operation of the battery pack.Technical SolutionAn embodiment of the present application provides a battery pack including at least two battery modules, each of the battery modules including a case and a plurality of battery cells disposed in the case, and wherein a side surface of the case is provided with a plurality of pressure relief holes, and wherein the plurality of pressure relief holes correspond to the plurality of battery cells one-to-one, and wherein an end of each of the battery cells has an explosion-proof hole connected to the corresponding pressure relief hole, and wherein two adjacent battery modules constitute a module component, and wherein in the same module component, two cases are disposed at a distance from each other to form a pressure relief passage, and wherein the pressure relief holes on the two cases respectively face the pressure relief passage.AdvantagesIn the present application, a plurality of battery modules are arranged in the battery pack, which is conducive to arranging more battery cells in a limited space for installation of the battery pack to increase the energy density of the entire battery pack. Further, two adjacent battery modules are spaced apart from each other to form a pressure relief passage, so that two adjacent battery modules share one pressure relief passage, which is conducive to improving space utilization of the battery pack. The two battery modules share a pressure relief passage, so that when thermal runaway occurs in the battery cells in two adjacent battery modules, the high temperature gases are discharged into the same pressure relief passage, i.e., the high temperature region during pressure relief is also concentrated in the pressure relief passage. This structure is suitable for the corresponding thermal insulation in the region of the pressure relief passage, whereby thermal insulation protection for the battery cells within the battery module can be achieved, and contributes to simplifying the overall structure of the battery pack. Since the pressure relief holes on the two battery modules respectively face the pressure relief passage and the high temperature gas is discharged into the pressure relief passage during the pressure relief, the thermal impact on the battery cell mainly concentrates on the end of the battery cell having the explosion-proof holes, thereby avoiding the thermal impact of the high temperature gas on the end of the battery cell having the positive and negative electrodes (i.e., the end of the battery cell remote from the explosion-proof holes) and the entire battery pack has good safety performance.SPECIFICATION OF THE APPLICATIONFIG. 1 shows a schematic diagram of a battery pack in an embodiment of the present application (with a remote battery module) FIG. 2 is a sectional view of a battery pack in an embodiment of the present application. FIG. 3 shows an enlarged view of the location A according to FIG. 2. FIG. 4 is a partial sectional view of a second clamping plate in an embodiment of the present application. FIG. 5 is a disassembled diagram of a battery pack in an embodiment of the present application. FIG. 6 is an enlarged view of the location B according to FIG. 5 ; FIG. 7 is a schematic diagram of a drain terminal in an embodiment of the present application. FIG. 8 shows a schematic diagram of a first fastening element in an exemplary embodiment of the present application. FIG. 9 is a schematic diagram of a second fastener in an embodiment of the present application. FIG. 10 is a schematic diagram of an insulating sleeve in an embodiment of the present application. FIG. 11 is a schematic diagram of an insulating protection box in an embodiment of the present application.List of reference characters1 Housing 11 First clamping plate 111 Outer plate 112 Inner plate 113 Insulating plate 12 Second clamping plate 121 Installation slot 122 Pressure relief hole 123 Limiting slot 13 Side plate 14 First fastening member 15 Second fastening member 151 Fastening plate 152 Positioning protrusion 153 Limiting protrusion 2 Battery cell 3 Spacer 4 Aerogel sheet 5 Adhesive layer 6 Heat conductive adhesive layer 7 Insulating protection box 71 Accommodation slot 8 Terminal component 81 Connection piece 82 Drain terminal 821 Main terminal 822 Branch terminal 9 Insulating sleeve 91 Socket slot 100 Battery module 200 Fastening structure member 300 Pressure relief passageCONCRETE EMBODIMENTSAs illustrated in FIGS. 1 to 5, the present application provides a battery pack including a battery module 100 and a fixing structure member 200. The number of the battery modules 100 is at least two, and all the battery modules 100 are arranged sequentially along a height direction (shown in the Z direction) of the battery pack. The number of battery modules 100 is an even number, so that two adjacent battery modules 100 therein form a group to form a module component. That is, the number of battery modules 100 included in the battery pack may be two, four, six, eight, etc. By providing a plurality of battery modules 100 in the battery pack, it is required to improve the electric energy storage capacity of the battery pack in the limited space in which the battery pack is installed, and thus to increase the energy density of the battery pack. In the present embodiment, the number of battery modules 100 is at least two, and two battery modules 100 are distributed in parallel and at intervals along a height direction of the battery pack. In the same module component, a pressure relief passage 300 is formed between two battery modules 100. When a thermal runaway occurs in the battery module 100, the two battery modules 100 share a pressure relief passage 300 for pressure relief protection.The battery module 100 includes a case 1, a battery cell 2, a spacer 3, an aerogel sheet 4, an insulating sleeve 9, an adhesive layer 5, a heat conductive adhesive layer 6, and a terminal component 8. the case 1 has an overall support and protection function, and the case 1 has a rectangular structure, a thickness direction of the case 1 is oriented parallel to a height direction of the battery pack. In the same module component, large surfaces of the two housings 1 are opposed to each other, and a pressure relief passage 300 is formed between the two housings 1. The housing 1 has a storage cavity for storing the battery cells 2 provided in a number of more than 1, and the plurality of battery cells 2 are distributed in an array in the storage cavity. The battery cell 2 is a cylindrical battery cell, and a length of the battery cell 2 extends along a thickness direction of the case 1. one end of the battery cell 2 has explosion-proof holes, so that when thermal runaway occurs in the battery cell 2, pressure relief protection can be achieved through the explosion-proof holes. An end of the battery cell 2 facing away from the explosion-protected hole has a positive pole and a negative pole. The connection component 8 acts as a depression and is electrically connected to the positive pole and the negative pole of the battery cell 2. A plurality of pressure relief holes 122 are provided on a side of the case 1 facing the pressure relief passage 300, and the number and position of the pressure relief holes 122 are provided in one-to-one correspondence with the plurality of battery cells 2. The explosion-proof holes of the battery cell 2 are connected to the corresponding pressure relief holes 122. All the pressure relief holes 122 on the two housings 1 face the pressure relief passage 300, respectively. That is, one end of the pressure relief holes 122 is connected to the explosion-proof holes and the other end is connected to the pressure relief passage 300. When thermal runaway occurs in the battery cell 2, the explosion-proof holes open, and the electrolyte and the high-temperature gas inside the battery cell 2 are discharged successively through the explosion-proof holes and the pressure relief holes 122 into the pressure relief passage 300. The spacer 3 and the aerogel sheet 4 both play a role in thermal insulation, and the two are set to block the pressure relief hole 122. When thermal runaway occurs in the battery cell 2, the high temperature gas causes the spacer 3 and the aerogel sheet 4 to be peeled from the case 1 by an impact and move with the high temperature gas into the pressure relief passage 300. For the battery cell 2 in which thermal runaway does not occur, the spacer 3 and the aerogel sheet 4 play an insulating role to prevent the movement of the high temperature gas in the pressure relief passage 300 toward the inside of the case 1 through the pressure relief holes 122, and thus to prevent the high temperature gas in the pressure relief passage 300 from thermally interfering with the battery cell 2 in the surrounding region in which thermal runaway does not occur. The insulating sleeve 9 serves as insulation, and the insulating sleeve 9 is fitted to an end portion of the battery cell 2 to avoid contact between the battery cell 2 and the surrounding metal parts.For example, the housing 1 includes a first clamping plate 11, a second clamping plate 12, and a side plate 13. the first clamping plate 11 and the second clamping plate 12 are arranged in parallel along a thickness direction (shown in the Z direction) of the housing 1 and spaced apart from each other. The side plate 13 is in the form of a square cylinder, the side plate 13 is disposed around the periphery of the first clamping plate 11 and the second clamping plate 12, and the both ends of the side plate 13 are connected to the first clamping plate 11 and the second clamping plate 12, respectively. The structure allows the first clamping plate 11, the second clamping plate 12 and the side plate 13 to enclose a receiving cavity. Pressure relief holes 122 are provided on the second clamping plate 12, and an end of all the battery cells 2 in the accommodation cavity provided with the explosion-proof holes faces the second clamping plate 12, and an end of the battery cells 2 having a positive pole and a negative pole faces the first clamping plate 11. Since the second clamping plate 12 serves as a side wall of the pressure relief passage 300, the second clamping plate 12 is a metal plate, and the material of the second clamping plate 12 may be an aluminum alloy 7075-T6 to improve the thermal conductivity of the second clamping plate 12. The use of a metal plate for the second clamping plate 12 helps to improve the mechanical strength and thermal conductivity of the second clamping plate 12, support the battery cell 2 well, and conduct the heat generated from the battery cell 2 to the outside through the second clamping plate 12. Now, the pressure release passage 300 may serve as a heat dissipation channel to promote the diffusion of the heat inside the entire battery module 100 to the outside.Referring to FIGS. 3, 4, and 10, a side surface of the second clamping plate 12 facing the battery cell 2 is provided with a plurality of installation slots 121, the plurality of installation slots 121 and the plurality of battery cells 2 being arranged one-to-one, respectively. The installation slits 121 are provided to install the battery cell 2, namely, an end of the battery cell 2 provided with the explosion-proof holes is inserted into the corresponding installation slit 121 to fix the battery cell 2. The pressure relief hole 122 is provided at the bottom of the installation slot 121, so that the installation slot 121 is connected to the pressure relief passage 300 through the pressure relief hole 122. The pressure relief hole 122 is a stepped hole including a large hole and a small hole connected to each other, the diameter of the large hole being larger than that of the small hole. The large hole is located on a side facing the battery cell 2, while the small hole is located on a side facing the pressure relief passage 300. In order to avoid a short circuit caused by the battery cell 2 coming into direct contact with the second clamping plate 12, an end of the battery cell 2 provided with the explosion-proof holes is covered with an insulating sleeve 9. The material of the insulating sleeve 9 is selected from flame retardant ABS+PC material in the relevant technology. One end of the insulating sleeve 9 is provided with a bush slot 91 that cooperates with the battery cell 2, and the wall thickness of the bush slot 91 is 0.5 mm to 1 mm. The wall thickness of the socket slot 91 includes, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, and 1 mm, but is not limited thereto. In the bottom of the female slot 91, a communication hole is penetratingly provided. In the installation, an end of the battery cell 2 provided with the explosion-proof holes is inserted into the socket slot 91, and an end of the battery cell 2 provided with the explosion-proof holes is inserted into the installation slot 121 of the second clamping plate 12 together with the insulating sleeve 9. Now, two ends of the communication hole are connected to the explosion-proof hole and the pressure relief hole 122, respectively. When thermal runaway occurs in the battery cell 2, the electrolyte and the high temperature gas inside the battery cell 2 are sequentially discharged into the pressure relief passage 300 through the explosion-proof holes, the communication holes, and the pressure relief holes 122. It should be noted that the installation shape between the insulating sleeve 9 and the battery cell 2 includes the following three types: a first type is that the insulating sleeve 9 is disposed on the side wall of the battery cell 2 and the insulating sleeve 9 is located near the end portion of the battery cell 2; a second type is that the insulating sleeve 9 is disposed on the end surface of the battery cell 2; and a third type is that the insulating sleeve 9 is disposed on the side wall and the end surface of the battery cell 2.Referring to FIG. 3, the adhesive layer 5 and the heat conductive adhesive layer 6 are filled in the accommodation cavity of the housing 1, for example. The adhesive layer 5 is a filler such as polyurethane, epoxy resin and silicone, and functions thereof are to fill the gap between adjacent battery cells 2 and take the role of protection and fixation of the battery cell 2. The heat conductive adhesive layer 6 is a two-component polyurethane heat conductive adhesive having a heat conductive effect so that the heat generated from the battery cell 2 can be conducted to the case 1 through the heat conductive adhesive layer 6 to facilitate the utilization of the larger surface of the case 1 for heat dissipation. In the present embodiment, the receiving cavity is filled with the heat conductive adhesive layer 6 and the adhesive layer 5, the adhesive layer 5 being disposed on a side of the receiving cavity in the vicinity of the first clamping plate 11 and the heat conductive adhesive layer 6 being disposed on a side of the receiving cavity in the vicinity of the second clamping plate 12. The battery cell 2 is embedded in the heat conductive adhesive layer 6 and the adhesive layer 5. By filling the accommodation cavity with the adhesive layer 5 and the heat conductive adhesive layer 6, the gap between the battery cell 2 and the case 1 is eliminated, thereby making installation of the battery cell 2 more stable and improving the performance of the battery pack in a vibration environment. At the same time, the heat conductive adhesive layer 6 is provided on the side of the accommodation cavity in the vicinity of the second clamping plate 12, which contributes to the heat generated from the battery cell 2 being conducted to the second clamping plate 12 through the heat conductive adhesive layer 6, thereby improving the heat dissipation performance of the entire battery module 100. Of course, in some embodiments, under the condition that the heat dissipation performance of the battery module 100 is satisfactory, it is also possible to omit the heat conductive adhesive layer 6 and fill the accommodation cavity with only the adhesive layer 5 with the battery cell 2 embedded in the adhesive layer 5.Referring to FIGS. 3, 5, and 7, the first clamping plate 11 exemplarily includes an outer plate 111, an inner plate 112, and an insulating plate 113. The outer plate 111, the insulating plate 113, and the inner plate 112 are stacked in the thickness direction of the housing 1. The outer plate 111 is disposed on a side facing away from the receiving cavity, the inner plate 112 is disposed on a side facing the receiving cavity, and the insulating plate 113 is disposed between the inner plate 112 and the outer plate 111. The material of the inner panel 112 is selected from flame retardant ABS+PC material in the relevant technology. The inner plate 112 is provided with a plurality of recesses, and the plurality of recesses are provided in one-to-one correspondence with the plurality of battery cells 2, and an end of the battery cell 2 facing away from the explosion-proof holes is inserted into the recesses on the inner plate 112 to realize the fixation of the battery cell 2. It can be seen that the both ends of the battery cell 2 are inserted and fixed into the inner plate 112 and the second clamping plate 12, respectively, to enable the inner plate 112 and the second clamping plate 12 to clamp the battery cell 2. The outer plate 111 is a metal plate, and the material of the outer plate 111 may be an aluminum alloy 7075-T6. The thickness of the outer plate 111 is 2 mm to 4 mm, for example, the thickness dimensions of the outer plate 111 include, but are not limited to, 2 mm, 2.5 mm, 3 mm, 3.5 mm, and 4 mm. Fixing the outer plate 111 as a metal plate is conducive to improvement in overall strength of the first clamping plate 11 and protection of circuit connections within the housing 1. the insulating plate 113 is made of an insulating material according to the related art, and the insulating plate 113 serves to insulate the outer plate 111 and avoid contact between the outer metal plate 111 and the internal electrical parts (e.g., the terminal component 8). In an embodiment, the insulating plate 113 is made of a glass fiber material, and the thickness of the insulating plate 113 is 0.5-0.7 mm. The thickness dimensions of the insulating plate 113 include, for example, 0.5 mm, 0.6 mm, and 0.7 mm, but are not limited thereto. Of course, in other embodiments, the insulating plate 113 may be omitted if the outer plate 111 is made of an insulating material.The terminal component 8 includes a connector 81 and a drain terminal 82, and both the connector 81 and the drain terminal 82 are conductors provided for conducting the circuit. The connectors 81 are provided in a number more than 1, and the number of the connectors 81 is designed to match the number of the battery cells 2. The connector 81 is attached to the inner plate 112, and two adjacent battery cells 2 are electrically connected by the connector 81. In practice, the connection shape of the connectors 81 is arranged according to the design index of the battery module 100 such that all the battery cells 2 are connected in series or in parallel. The drain terminals 82 are provided in a number of more than 1, and the drain terminals 82 are mounted on the inner panel 112. The drain terminals 82 are passed through the housing 1, i.e., one end of the drain terminal 82 extends into the receiving cavity of the housing 1 and the other end extends to the outside of the housing 1. an outer end of the drain terminal 82 has a main terminal 821, the main terminal 821 being provided for electrical connection with an external electrical component. An inner end of the drain terminal 82 has a plurality of branch terminals 822, the branch terminals 822 being provided for electrical connection with the connector 81. By means of the drain terminal 82 and the connector 81, the current of all the battery cell 2 is conducted to the main terminal 821 disposed outside the case 1, which facilitates connection to the external electrical component.Referring to FIGS. 1, 5, and 11, the battery module 100 further includes an insulating protection box 7 by way of example. the insulating protection box 7 is made of an insulating material such as a flame retardant ABS+PC material in the relevant technology. The insulating protection box 7 is snapped onto the main terminal 821 of the drain terminal 82 so that the insulating protection box 7 can provide insulating protection for the drain terminal 82 located outside the housing 1. The shape of the insulating protection box 7 is fitted to the main terminal 821 so that the insulating protection box 7 can be wound around the outside of the main terminal 821. The insulating protection box 7 is provided with a receiving slot 71, and the main terminal 821 is inserted into the receiving slot 71.Referring to FIGS. 1, 8, and 9, the housing 1 further includes, by way of example, a first fastening member 14 and a second fastening member 15. the first clamping plate 11 and the second clamping plate 12 are connected and fastened to each other by the first fastening member 14 and the second fastening member 15. The first fastening members 14 are provided in a number of more than 1, and the plurality of first fastening members 14 are spaced around the circumferential direction of the housing 1. The first fixing member 14 is a square frame structure, and the first fixing member 14 is set as a hollow structure to satisfy a lightweight construction. Two ends of the first fastening member 14 are inserted into the first clamping plate 11 and the second clamping plate 12, respectively, to position the first clamping plate 11 and the second clamping plate 12. The second fastening members 15 are provided in a number of more than 1, and the plurality of second fastening members 15 are spaced around the circumferential direction of the housing 1. The second fixing member 15 includes a fixing plate 151, a positioning protrusion 152, and a limiting protrusion 153. The positioning protrusions 152 are provided in a number of 2, the two positioning protrusions 152 are arranged in parallel and at a distance from each other on a side surface of the fixing plate 151, and the distance between the two positioning protrusions 152 corresponds to the distance between the first clamping plate 11 and the second clamping plate 12. The restricting protrusions 153 are provided in a number of 2, the two restricting protrusions 153 are disposed on the same side surface as the two positioning protrusions 152, and the two restricting protrusions 153 are disposed at two ends of the fixing plate 151 in the length direction. Referring to FIGS. 1 and 6, a restriction slot 123 is provided at the peripheral portion of the second clamping plate 12 correspondingly, which fits with the restriction protrusion 153. Also, on the outer plate 111 of the first clamping plate 11, a restriction slot 123 is provided, which mates with the restriction protrusion 153. When the housing 1 is installed, two ends of the first fixing member 14 are inserted into the first clamping plate 11 and the second clamping plate 12, respectively, to maintain an appropriate distance between the first clamping plate 11 and the second clamping plate 12. In addition, two ends of the fixing plate 151 of the second fixing member 15 in the length direction abut on the peripheral portions of the first clamping plate 11 and the second clamping plate 12, respectively, and the two ends of the fixing plate 151 in the length direction are connected to the first clamping plate 11 and the second clamping plate 12, respectively, by fixing members. The fastening elements are screws. The two positioning projections 152 are inserted into the gap between the first clamping plate 11 and the second clamping plate 12 so that the two positioning projections 152 abut on the opposite sides of the first clamping plate 11 and the second clamping plate 12, respectively. With this structure, the positioning protrusions 152 play a role in positioning the first cleat 11 and the second cleat 12 to maintain an appropriate distance between the first clamping plate 11 and the second clamping plate 12. At the same time, the two restricting protrusions 153 are inserted into the restricting slots 123 on the first clamping plate 11 and the second clamping plate 12, respectively, to restrict the entire second fastening member 15 from sliding along the length direction (shown in the X direction) or the width direction (shown in the Y direction) of the housing 1, thereby playing a restricting function. Of course, in some exemplary embodiments, it is also possible to provide the first fastening element 14 separately or the second fastening element 15 separately between the first clamping plate 11 and the second clamping plate 12.The first fixing member 14 is a metal plate of which stainless steel is SUS304, and the thickness of the metal plate is 8 mm-12 mm. The second fixing member 15 is a metal plate of which stainless steel is SUS304, and the thickness of the metal plate is 25 mm-35 mm.To improve the overall structural strength of the battery module 100, the housing 1 further includes a plurality of connection posts, by way of example. The plurality of connection posts are installed in the accommodation cavity of the housing 1, the connection posts are inserted into the gap between adjacent battery cells 2, and two ends of the connection posts are connected and fixed to the first clamping plate 11 and the second clamping plate 12, respectively, by fastening members.Referring to FIG. 1, the fixing structure member 200 is exemplarily provided for assembling the battery module 100, and the battery module 100 is connected and fixed to the fixing structure member 200 by fixing members. The number and position of the fixing structure member 200 are provided in one-to-one correspondence with the number and position of the second fixing member 15, and the second fixing member 15 is connected and fixed to the fixing structure member 200 by fixing members. It is also understood that two or more battery modules 100 are connected to each other by the fixing structure members 200 to form a battery pack.Referring to FIGS. 3 and 4, the spacer 3 is exemplarily a circular thin plate structure, the material of the spacer 3 is selected from gold mica, and the thickness of the spacer 3 is 0.4 mm to 0.6 mm, for example, the thickness dimensions of the spacer 3 include, but are not limited to, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, and 0.6 mm. The spacer 3 is mounted on a side surface of the second clamping plate 12 facing the pressure relief passage 300 and allows the spacer 3 to selectively seal the pressure relief holes 122. Optionally, the spacer 3 is glued and fastened to the second clamping plate 12. When thermal runaway occurs in the battery cell 2, the spacer 3 is released from the second clamping plate 12 under the action of the high pressure gas to connect the pressure relief hole 122 to the pressure relief passage 300. The aerogel sheet 4 is a circular thin plate structure, and the aerogel sheet 4 serves as a heat insulator and is mounted in a large hole of the pressure relief hole 122. The aerogel sheet 4 is elastic, and when thermal runaway occurs in the battery cell 2, the aerogel sheet 4 deforms under the action of the high pressure gas and moves into the pressure relief passage 300 through the small holes of the pressure relief holes 122 to connect the pressure relief holes 122 to the pressure relief passage 300. In the present embodiment, by providing the aerogel sheet 4 inside the pressure relief hole 122 and covering the end portion of the pressure relief hole 122 with the spacer 3, high-temperature and high-pressure gases inside the pressure relief passage 300 are prevented from entering the proximal pressure relief holes 122, thereby preventing the proximal battery cells 2 not subject to thermal runaway from being thermally deteriorated. At the same time, due to the presence of the spacer 3 and the aerogel sheet 4, the thermal insulation effect between the battery cell 2 and the pressure relief passage 300 is improved by the overlapping thermal insulation effect of the two. By installing the aerogel sheet 4 inside the pressure relief hole 122, i.e., only the spacer 3 is located inside the pressure relief passage 300, the structure can reduce the space occupation of the heat insulating parts on the pressure relief passage 300 while satisfying the need to improve the efficiency of the gas flow inside the pressure relief passage 300 and prevent the nearby battery cell 2 from being thermally deteriorated upon occurrence of thermal runaway.In the present embodiment, a plurality of battery modules 100 are arranged in the battery pack, which is conducive to arranging more battery cells 2 in a limited space for installation of the battery pack to increase the energy density of the entire battery pack. Further, two adjacent battery modules 100 are spaced apart from each other to form a pressure relief passage 300, so that two adjacent battery modules 100 share one pressure relief passage 300, which is conducive to improving the space utilization of the battery pack. The two battery modules 100 share a pressure relief passage 300 so that when thermal runaway occurs in the battery cells 2 in two adjacent battery modules 100, the high temperature gases are discharged into the same pressure relief passage 300, i.e., the high temperature region during pressure relief is also concentrated in the pressure relief passage 300. This structure is suitable for the corresponding thermal insulation in the region of the pressure relief passage 300, whereby thermal insulation protection for the battery cells 2 within the battery module 100 can be achieved, and contributes to simplification of the overall structure of the battery pack. Since the pressure relief holes 122 on the two battery modules 100 respectively face the pressure relief passage 300 and the high temperature gas is discharged into the pressure relief passage 300 during the pressure relief, the thermal action on the battery cell 2 mainly concentrates on an end of the battery cell 2 provided with the explosion-proof holes, thereby avoiding the thermal action of the high temperature gas on the end of the battery cell 2 having the positive and negative electrodes and the entire battery pack has good safety performance.

Claims

A battery pack comprising at least two battery modules, wherein each of the battery modules comprises a case and a plurality of battery cells arranged in the case, and wherein a side surface of the case is provided with a plurality of pressure relief holes, and wherein the plurality of pressure relief holes of the plurality of battery cells correspond one-to-one, and wherein an end of each of the battery cells has an explosion-proof hole connected to the corresponding pressure relief hole, and wherein two adjacent battery modules form a module component, and wherein in the same module component, two cases are arranged at a distance from each other to form a pressure relief passage, and wherein the pressure relief holes on the two cases respectively face the pressure relief passage.The battery pack of claim 1, wherein each of the battery modules further comprises a spacer, and wherein each of the pressure relief holes is associated with one of the spacers, and wherein the spacer is installed on a side surface of the housing facing the pressure relief passage, and wherein the spacer is caused to selectively plug the pressure relief hole.The battery pack of claim 1, wherein each of the battery modules further comprises an aerogel sheet disposed in the pressure relief hole, and wherein when the battery cell is depressurized, a pressure relief airflow is capable of driving the aerogel sheet to move toward the pressure relief passage.The battery pack according to claim 3, wherein the pressure relief hole is a stepped hole including a large hole and a small hole connected to each other, and wherein the large hole is located on a side facing the battery cell and the small hole is located on a side facing the pressure relief passage, and wherein the aerogel sheet is disposed in the large hole.The battery pack according to claim 1, wherein each of the battery modules further comprises an insulating sleeve, wherein each of the battery cells is associated with one of the insulating sleeves, and wherein the insulating sleeve is fitted to an end of the battery cell provided with the explosion-proof hole, and wherein an installation slot for installing the battery cell is provided on the inner wall of the case, and wherein the pressure relief hole is provided on the bottom of the installation slot, and wherein a communication hole is continuously provided on the insulating sleeve, and wherein the insulating sleeve is inserted into the installation slot and allows two ends of the communication hole to be respectively connected to the explosion-proof hole and the pressure relief hole.The battery pack according to any one of claims 1 to 5, wherein the housing comprises a first clamping plate, a second clamping plate, and a side plate, and wherein the first clamping plate and the second clamping plate are arranged parallel to each other and at intervals, and wherein the side plate encloses the periphery of the first clamping plate and the second clamping plate, and wherein two ends of the side plate are connected to the first clamping plate and the second clamping plate, respectively, such that the first clamping plate, the second clamping plate, and the side plate enclose a receiving cavity for receiving the battery cell, and wherein the pressure relief hole is provided at the second clamping plate.The battery pack of claim 6, wherein the second clamping plate is a metal plate.The battery pack of claim 6, wherein the interior of the receiving cavity is filled with an adhesive layer, and wherein the battery cell is embedded in the adhesive layer.The battery pack of claim 8, wherein the interior of the receiving cavity is further filled with a thermally conductive adhesive layer located on a side of the receiving cavity facing the second clamping plate, and wherein the adhesive layer is located on a side of the receiving cavity facing the first clamping plate, and wherein the battery cell is embedded in the thermally conductive adhesive layer and the adhesive layer.The battery pack of claim 6, wherein the housing further comprises at least one of a first fixing member and a second fixing member, and wherein two opposite ends of the first fixing member are inserted into the first clamping plate and the second clamping plate, respectively, and wherein the second fixing member comprises a fixing plate and two positioning protrusions spaced on the fixing plate, and wherein the two positioning protrusions abut opposite sides of the first clamping plate and the second clamping plate, respectively, and wherein two ends of the fixing plate are connected to the first clamping plate and the second clamping plate, respectively, by a fixing member.The battery pack of claim 6, wherein the first clamping plate comprises an outer plate and an inner plate that are arranged in a stacked manner, and wherein an end of the battery cell facing away from the explosion-proof hole is inserted into the inner plate, and wherein the outer plate is located on a side of the inner plate facing away from the battery cell.

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