Battery Pack

Abstract

The present invention discloses a battery pack, which relates to the field of batteries and is used to optimize the structure of the battery pack. The battery pack includes a box body and a battery module. The box body includes a accommodating cavity and a drainage hole connected to the accommodating cavity. The battery module is installed inside the accommodating cavity. Among them, a liquid storage cavity for storing liquid is provided below the battery module, and the liquid storage cavity is connected to the drainage hole. The above technical scheme provides a liquid storage cavity, and when liquid accumulates inside the box body, the liquid can flow into the liquid storage part to prevent the battery module inside the box body from short circuiting and other dangers, thereby optimizing the structure and performance of the battery pack.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and in particular to a battery pack. Background Art

[0002] The battery pack includes a battery module, a box for mounting the battery module, and a cooling system for dissipating heat from the battery module. The battery module is mounted inside the box.

[0003] The inventors have found that the prior art has at least the following problems: water may accumulate in the box when it rains or in other watery conditions; or the cooling system inside the box may leak. These situations can easily cause a short circuit between the positive and negative electrodes of the battery module. Summary of the invention

[0004] The present invention provides a battery pack to optimize the structure of the battery pack.

[0005] An embodiment of the present invention provides a battery pack, including:

[0006] A box body, comprising a containing cavity and a drainage hole communicated with the containing cavity; and

[0007] A battery module is installed inside the accommodating cavity;

[0008] Wherein, a liquid storage cavity for storing liquid is provided below the battery module, and the liquid storage cavity is communicated with the liquid discharge hole.

[0009] In some embodiments, the battery pack further comprises:

[0010] A liquid storage part, arranged outside the box;

[0011] Wherein, the liquid storage part is provided with the liquid storage cavity, or the liquid storage part and the box body together form the liquid storage cavity.

[0012] In some embodiments, the liquid storage part is installed below the wall of the box body provided with the drainage hole, and the liquid storage part is sealedly connected to the wall body; wherein the liquid storage part and the wall body form the liquid storage cavity.

[0013] In some embodiments, the liquid storage portion is provided with an inner recessed portion that is recessed in a direction away from the box body.

[0014] In some embodiments, there are a plurality of drainage holes, and the inner recess is located outside of all the drainage holes and covers all the drainage holes.

[0015] In some embodiments, the battery pack further comprises:

[0016] The protection part is installed on a side of the liquid storage part away from the box body.

[0017] In some embodiments, the hardness of the protective portion is greater than the hardness of the liquid storage portion, and the protective portion completely covers the liquid storage portion.

[0018] In some embodiments, the housing comprises:

[0019] a first housing; and

[0020] The second box body and the first box body form the accommodating cavity and are located below the first box body; the drainage hole is arranged in the second box body.

[0021] In some embodiments, the second housing comprises:

[0022] a box body; and

[0023] The carrier is arranged inside the box body; the carrier divides the internal space of the box body into a containing cavity and a liquid storage cavity; the carrier is provided with the drain hole, and the battery module is carried by the carrier.

[0024] In some embodiments, a bottom of the box body is provided with a concave area that is recessed in a direction away from the first box body, and the supporting member is connected to an edge of the concave area.

[0025] In some embodiments, the battery module comprises:

[0026] A battery cell assembly, comprising a plurality of battery cells arranged side by side; and

[0027] A cooling system, abutting against the plurality of battery cells and used for cooling each of the battery cells;

[0028] Wherein, the drain hole is used to discharge the fluid leaked from the cooling system.

[0029] In some embodiments, the cooling system comprises:

[0030] A cooling plate, wherein a cooling channel is provided inside, and the number of cooling plates is more than two; and

[0031] A connecting pipe connected to the cooling plates to connect the cooling channels of the cooling plates;

[0032] Wherein, the drainage hole is adjacent to the connection between the cooling plate and the connecting pipe.

[0033] In some embodiments, the battery cells of the battery module are arranged along the length direction of the box body, and the largest side surface of each battery cell faces the wall of the box body where the drainage hole is located.

[0034] In some embodiments, there are a plurality of drainage holes arranged along the width direction of the box body.

[0035] In some embodiments, the opening size of one end of the drainage hole communicating with the accommodating cavity is larger than the opening size of the other end communicating with the liquid storage portion.

[0036] In the above technical solution, the battery pack has a box body and a battery module disposed inside a receiving cavity of the box body. During actual use of the battery pack, there may be liquid inside the receiving cavity of the box body. In order to prevent the liquid from contacting the positive and negative electrodes of the battery module and causing a short circuit of the battery module, the above technical solution provides a liquid storage portion below the battery module. The liquid storage portion is connected to the receiving cavity of the box body through a liquid discharge hole, and the liquid in the receiving cavity can be discharged into the liquid storage cavity through the liquid discharge hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0038] Figure 1 A schematic diagram of the three-dimensional structure of a battery pack provided in an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of a three-dimensional structure of a partial structure of a battery pack provided by an embodiment of the present invention;

[0040] Figure 3 for Figure 2 A local enlarged schematic diagram;

[0041] Figure 4 A schematic diagram of the structure of a battery cell of a battery pack provided by an embodiment of the present invention;

[0042] Figure 5 It is a structural schematic diagram of a laminated electrode assembly;

[0043] Figure 6 is a schematic diagram of the structure of a wound electrode assembly;

[0044] Figure 7 A schematic diagram of the exploded structure of a battery pack provided by an embodiment of the present invention;

[0045] Figure 8 A schematic diagram of the exploded components of the second box of a battery pack provided by an embodiment of the present invention;

[0046] Fig. 9 A schematic diagram of the three-dimensional structure of the second box of the battery pack provided in an embodiment of the present invention;

[0047] Fig.10A partial three-dimensional schematic diagram of the second box of a battery pack provided by an embodiment of the present invention;

[0048] Fig.11 for Fig.10 B is a partial enlarged schematic diagram;

[0049] Fig.12 A schematic diagram of a partial three-dimensional structure of a battery pack provided by another embodiment of the present invention;

[0050] Fig.13 A schematic diagram of a partial three-dimensional structure of a battery pack provided by another embodiment of the present invention;

[0051] Fig.14 for Fig.13 A local enlarged schematic diagram of D;

[0052] Fig.15 for Fig.14 A partial cross-sectional schematic diagram in the direction of C;

[0053] Fig.16 A schematic diagram of the exploded structure of a battery pack carrier, a second box body and a protective portion provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0054] Combine the following Figures 1 to 16 The technical solution provided by the present invention is described in more detail.

[0055] In order to more clearly describe the technical solutions of the embodiments of the present invention, Figure 1 The coordinate system is established in , and the subsequent description of the various positions of the battery pack is based on this coordinate system. Figure 1 , the X-axis is the length direction of the battery pack. The Y-axis is perpendicular to the X-axis in the horizontal plane, and the Y-axis represents the width direction of the battery pack. The Z-axis is perpendicular to the plane formed by the X-axis and the Y-axis, and the Z-axis represents the height direction of the battery module. In the description of the present invention, the terms "upper" and "lower" are all relative to the Z-axis direction. The length direction of the box 1 is consistent with the length direction of the battery pack, the width direction of the box 1 is consistent with the width direction of the battery pack, and the height direction of the box 1 is consistent with the height direction of the battery pack.

[0056] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by the terms "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships 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 protection content of the present invention.

[0057] See also Figure 1 , Figure 1The three-dimensional structure of the battery pack is shown, and the box 1 is in an open state. Figure 2 , Figure 2 One side wall of the second box body 14 of the box body 1 described later is removed to clearly show the structure of the battery module 2 inside the box body 1 and the positional relationship between the battery module 2 and the second box body 14.

[0058] See also Figures 1 to 3 An embodiment of the present invention provides a battery pack, including a case 1 and a battery module 2. The case 1 includes a receiving chamber 11 and a drainage hole 12 connected to the receiving chamber 11. The battery module 2 is installed inside the receiving chamber 11. A liquid storage chamber 10 for storing liquid is provided below the battery module 2, and the liquid storage chamber 10 is connected to the drainage hole 12. The "below" mentioned here can be directly below or obliquely below, as long as the liquid inside the receiving chamber 11 can flow through the drainage hole 12 into the liquid storage chamber 10 under the action of gravity.

[0059] The liquid storage chamber 10 is, for example, located inside and / or outside the housing 1. Specifically, there are three types of locations for the liquid storage chamber 10: the first type is that the liquid storage chamber 10 is completely located inside the housing 1; the second type is that the liquid storage chamber 10 is completely located outside the housing 1; the third type is that the liquid storage chamber 10 is partially located inside the housing 1 and the other part is located outside the housing 1. The various implementation methods will be described in detail below according to different situations.

[0060] In the above technical solution, the battery pack is provided with a liquid storage chamber 10, and the liquid storage chamber 10 is located below the battery module 2 in the direction of gravity. When liquid accumulates in the accommodating chamber 11, the accumulated liquid flows downward under the action of gravity, flows to the drainage hole 12, and flows into the liquid storage chamber 10 through the drainage hole 12 for storage. It can be seen that the above technical solution, since the liquid storage chamber 10 is provided below the battery module 2, reduces or even avoids the phenomenon of short circuit of the battery module 2 caused by the fluid in the accommodating chamber 11, thereby improving the safety of the battery pack. In addition, the above technical solution is not limited by the placement height of the battery module 2. When the height of the battery module 2 is low and the position of its electrode terminals is low, it can also reduce the risk of short circuit of the battery module 2 and improve the safety of the battery pack.

[0061] Next, the various components of the battery pack will be described in detail with reference to the accompanying drawings.

[0062] First, the implementation of the box 1 is introduced.

[0063] See also Figures 1 to 3 In some embodiments, the box body 1 includes a first box body 13 and a second box body 14. The second box body 14 and the first box body 13 enclose a receiving cavity 11, and the second box body 14 is located below the first box body 13. The drain hole 12 is provided in the second box body 14.

[0064] The first box body 13 and the second box body 14 are buckled together to form the above-mentioned accommodating chamber 11. The first box body 13 and the second box body 14 can be connected by bolts or other detachable connection methods. Preferably, the box body 1 is formed by piecing together two halves of the box body, which is convenient for installing, replacing, repairing and maintaining the various components located in the accommodating chamber 11 of the box body 1 on the one hand, and also makes the manufacturing and processing of the box body 1 easier on the other hand. In addition, the structure of the box body 1 is neat, so that the battery pack can be easily installed on the vehicle.

[0065] See also Figure 1 The box 1 is used to install the battery module 2. The box 1 and the battery module 2 are detachably connected, for example, a connection frame is installed on the inner wall of the box 1, and a connecting piece is provided on the battery module 2, and a detachable connection between the connection frame and the connecting piece is achieved by bolts or the like. The above implementation method makes the connection between the battery module 2 and the box 1 stable and reliable, and the structure of the battery pack is reliable.

[0066] See also Figure 1 The drainage hole 12 mentioned above is arranged at the bottom of the second box body 14. When liquid accumulates inside the accommodating chamber 11, the fluid in the accommodating chamber 11 automatically flows out of the accommodating chamber 11 through the drainage hole 12 under the action of its own gravity, thereby realizing automatic drainage of the accumulated liquid in the accommodating chamber 11.

[0067] See also Figures 1 to 7 , the following introduces the relevant contents of battery module 2.

[0068] The battery module 2 includes a battery cell assembly 21 and a cooling system 22. The battery cell assembly 21 includes a plurality of battery cells 210 arranged side by side. The plurality of battery cells 210 are electrically connected to each other. The cooling system 22 is used to cool the battery cell assembly 21 of the battery module 2. The cooling system 22 is filled with a cooling fluid. Leakage may occur at the connection between the components of the cooling system 22. The drain hole 12 is used to discharge the fluid leaked from the cooling system 22, so that there is little or no fluid accumulation inside the box body 1, reducing or even eliminating the risk of short circuit in the battery pack.

[0069] See also Figure 1 and Figure 7 The battery module 2 may include a plurality of battery cell assemblies 21 , and the electrical connection between the battery cell assemblies 21 may be set to series connection, parallel connection, or both series connection and parallel connection as required to achieve the electrical performance required by the battery pack.

[0070] See also Figures 4 to 6 , the structure of the battery cell 210 is described below.

[0071] See also Figure 4The battery cell 210 includes a housing 211, an electrode assembly 212 disposed inside the housing 211, a connector 213 disposed at an end of the electrode assembly 212, and a cap plate 214 covering the connector 213 and the end of the electrode assembly 212. The cap plate 214 is provided with an electrode terminal 215.

[0072] The housing 211 is closed at one end and open at the other end. The cover plate 214 is disposed at the open end of the housing 211. The electrode assembly 212 is installed inside the housing 211 through the open end. The largest side of the electrode assembly 212 faces the largest side of the housing 211, and the largest side of the housing 211 serves as the largest side A of the battery cell.

[0073] The electrode assembly 212 can be manufactured in a lamination manner or a winding manner. Figure 5 As shown, the laminated electrode assembly 212 is formed by cutting the positive electrode sheet 216, the negative electrode sheet 217, and the separator 218 into a specified size, and then laminating the positive electrode sheet 216, the separator 218, and the negative electrode sheet 217 into the electrode assembly 212. Figure 6 As shown, the wound electrode assembly 212 is formed by winding a positive electrode sheet 216 , a negative electrode sheet 217 , and a separator 218 .

[0074] The largest surface of the laminated electrode assembly 212 and the wound electrode assembly 212 is the surface with the largest expansion rate. Figure 1 and Figure 2 As shown, this placement method can effectively reduce the expansion accumulation of the battery cell assembly 21, thereby reducing the expansion accumulation of the battery pack, because the maximum expansion surface of the battery cell 210 is along the Z-axis direction, and the size of the battery module 2 along the Z-axis direction is smaller than the size along the X-axis or Y-axis direction.

[0075] See also Figure 1 , Figure 2 and Figure 7 , the arrangement of the battery cells 210 of the battery cell assembly 21 is described below.

[0076] See also Figure 1 , Figure 2 and Figure 7 The plurality of battery cells 210 are arranged along the length direction of the box body 1 , and the largest side surface of each battery cell 210 faces the wall 15 of the box body 1 where the drainage hole 12 is located.

[0077] by Figure 1 For the coordinate system shown, multiple battery cells 210 are arranged flat along the length direction X of the box 1, that is, the largest side A of the battery cell 210 is roughly parallel to the length direction X of the box 1, and the largest side A of the battery cell 210 faces the wall 15 of the box 1.

[0078] like Figure 1 As shown, two rows of battery cell assemblies 21 are arranged along the width direction of the battery pack (i.e., the Y-axis direction). In actual application, three rows or more may also be arranged. In actual use, as required, in the height direction of the battery pack, i.e., Figure 1 In the Z-axis direction, one or more layers of battery cell assemblies 21 may also be arranged.

[0079] The placement of the largest side A of the battery cell 210 and the wall 15 of the box body 1 facing each other is also called flat placement. With the flat placement, since the height of the battery cell assembly 21 in the Z direction is relatively short, the overall height of the battery pack can be reduced, so the battery pack of this structure is more suitable for vehicles with a relatively short battery pack installation space. However, due to the low height of the battery cell assembly 21, the position of the bus bar of the battery cell 210 is also low, and the electrode terminal 215 is relatively close to the bottom of the box body 1. If the structure of the embodiment of the present invention is not adopted, when the cooling system 22 inside the box body 1 leaks and liquid accumulates in the box body 1, the flat battery cell 210 is more likely to short-circuit.

[0080] If the above structure of the embodiment of the present invention is adopted, the above two problems can be well balanced, so that the height of the battery pack can be relatively short to meet the vehicle installation requirements; and the short circuit phenomenon is not easy to occur inside the battery pack, thereby improving the performance of the battery pack. Since the battery pack has a liquid storage part 3, the liquid storage part 3 is connected to the accommodating chamber 11 through the drainage hole 12, and the accumulated liquid in the accommodating chamber 11 can flow out of the accommodating chamber 11 in time through the drainage hole 12, the possibility of water accumulation in the box body 1 is effectively reduced, and the possibility of short circuit phenomenon in the battery module is reduced or even avoided, thereby improving the performance and structure of the battery pack.

[0081] In addition, with the above arrangement, each battery cell 210 of the battery module 2 is placed flat. Since the maximum expansion surface of each battery cell 210 included in the battery cell assembly 21 is along the Z-axis direction, the cumulative expansion of each battery cell 210 is small, thereby optimizing the performance of the battery pack.

[0082] See also Figures 1 to 4 , the following introduces the relevant contents of the cooling system 22 of the battery module 2.

[0083] The cooling system 22 is disposed outside the battery cell assembly 21 and is used to cool the battery cell assembly 21. Optionally, the cooling system 22 cools the bottom surface of the battery cell assembly 21. The bottom surface of the battery cell assembly 21 refers to the surface of each battery cell 210 included in the battery cell assembly 21 that is opposite to the top surface where the electrode terminal 215 is provided.

[0084] See also Figure 1 and Figure 2In some embodiments, two rows of battery cell assemblies 21 share a cooling system 22. Figure 1 As shown, the top surfaces of the two rows of battery cell assemblies 21 with electrode terminals 215 are opposite to each other, and the cooling system 22 is used to cool the bottom surfaces of the two rows of battery cells at the same time. Alternatively, the top surfaces of the two rows of battery cells with electrode terminals 215 are far away from each other. The bottom surfaces of the battery cells 210 of the two rows of battery cell assemblies 21 are arranged opposite to each other, and there is a gap between the two rows of battery cell assemblies 21. The cooling plate 221 of the cooling system 22 is arranged at the gap to cool the bottom surfaces of the two rows of battery cell assemblies 21 at the same time.

[0085] See also Figures 1 to 3 As mentioned above, in some embodiments, the cooling system 22 includes a cooling plate 221 and a connecting pipe 222. A cooling channel (not shown) is provided inside the cooling plate 221, and the number of cooling channels is one or more than two. There are more than two cooling plates 221. The connecting pipe 222 is connected to the cooling channel to connect the cooling plates 221. The drain hole 12 is adjacent to the connection between the cooling plate 221 and the connecting pipe 222.

[0086] Preferably, a liquid inlet pipe and a liquid discharge pipe may be additionally provided on the outside of the box body 1, and the cooling system 22 is connected to both the liquid inlet pipe and the liquid discharge pipe. This structure realizes the circulation of coolant inside the cooling system 22, thereby improving the cooling effect of the battery pack.

[0087] See also Figure 1 and Figure 3 The cooling system 22 includes two connecting pipes 222, which are respectively located on both sides of the length direction of the battery module 2. Below the connection position of each connecting pipe 222 and the cooling plate 221, one or more rows of drainage holes 12 are provided. When leakage occurs at the connection between the connecting pipe 222 and the cooling plate 221, the drainage holes 12 can drain the accumulated liquid in time to ensure the normal use of the battery module 2 inside the box 1.

[0088] See also Figures 1 to 4 The cooling system 22 is disposed between the two end surfaces of the battery cell assembly 21. Figure 1 As shown, one of the two cooling plates 221 of the cooling system 22 cools the bottom surface of one battery cell assembly 21, and the other cooling plate 221 cools the bottom surface of another battery cell assembly 21. The above arrangement realizes the use of one cooling system 22 to cool two battery cell assemblies 21 at the same time, reduces the number of cooling components, and makes the structure of the battery pack lightweight.

[0089] See also Figures 1 to 3 , Figures 7 to 11 , the relevant contents of the drainage hole 12 are further described in detail below.

[0090] The battery module 2 is integrally mounted on one of the walls of the box 1, which is referred to as the wall 15. The drain hole 12 is also provided on the wall 15 of the box 1. Figure 1 Taking the direction shown as an example, the wall 15 is the bottom wall of the box body 1. In addition, the drain hole 12 is located below the battery module 2 in the gravity direction.

[0091] by Figure 1 Taking the direction shown as an example, the drain hole 12 is arranged at the bottom of the box body 1. Such arrangement enables the liquid to flow directly to the drain hole 12 under the action of gravity and then flow into the liquid storage chamber 10 when the cooling system 22 described later inside the box body 1 leaks. Figure 3 As indicated by the path M in FIG.

[0092] See also Figure 1 , Figure 7 In some embodiments, the drainage holes 12 are arranged in a row on the wall 15 of the box body 1 , and the drainage holes 12 penetrate the wall 15 .

[0093] The drainage hole 12 is, for example, a circular hole, a trapezoidal hole, a special-shaped hole, etc. The shape of the drainage hole 12 is not limited, and its function is to allow the accumulated fluid to pass through and flow smoothly into the liquid storage chamber 10. The drainage hole 12 in the shape of a circular hole is convenient for processing and manufacturing. The drainage hole 12 in the shape of a trapezoidal hole has a size that is larger than the size of the end of the drainage hole 12 that is connected to the accommodating chamber 11. This structure effectively reduces the possibility of backflow of the fluid in the liquid storage chamber 10. The drainage hole 12 in the shape of a special-shaped hole can realize the arbitrary design of the structure, shape and size of the drainage hole 12 according to needs, meeting personalized connection requirements.

[0094] In some embodiments, the drainage hole 12 is configured to allow liquid to flow from the drainage hole 12 to the liquid storage chamber 10 in one direction. Alternatively, a direction regulating component is provided at the drainage hole 12 to allow liquid to flow from the drainage hole 12 to the liquid storage portion 3 in one direction.

[0095] For example, the drainage hole 12 is configured as a special-shaped structure, or one end is larger than the other end. Alternatively, an anti-reflux film is provided at the end of the drainage hole 12 to prevent backflow.

[0096] In some embodiments, the opening size of the end of the drainage hole 12 that is connected to the accommodating chamber 11 is large, and the opening size of the end that is connected to the liquid storage chamber 10 is small. The end with the large size is located upstream in the direction of gravity, and the end with the small size is located downstream in the direction of gravity. This structure makes it difficult for the liquid to flow back into the box body 1 through the drainage hole 12 when the box body 1 is inverted.

[0097] Through the above arrangement, after the accumulated liquid in the accommodating chamber 11 of the box body 1 flows out into the liquid storage chamber 10 through the drainage hole 12, during the use of the battery pack, even if there are unexpected situations such as bumps and collisions, the fluid in the liquid storage chamber 10 is not easy to flow back into the accommodating chamber 11, thereby reducing the risk of short circuit of the battery module 2 caused by the fluid in the liquid storage chamber 10 flowing back to the accommodating chamber 11, optimizing the structure of the battery pack, and improving the performance of the battery pack.

[0098] See also Figure 1 Next, various implementations of the liquid storage chamber 10 are introduced.

[0099] According to the position of the liquid storage chamber 10 , the liquid storage chamber 10 may be located inside or outside the housing 1 , or partially inside and partially outside the housing 1 .

[0100] The following first introduces the implementation method of the liquid storage chamber 10 being located outside the box body 1.

[0101] exist Figure 1 In the embodiment shown, the battery pack further includes a liquid storage portion 3. The liquid storage portion 3 is disposed outside the box body 1. The liquid storage portion 3 is independently provided with a liquid storage cavity 10, or the liquid storage portion 3 and the box body 1 together form the liquid storage cavity 10.

[0102] See also Figure 1 The liquid storage part 3 is located outside the bottom of the box body 1, and the liquid storage part 3 is fixed to the bottom wall of the box body 1.

[0103] When the liquid storage part 3 is provided with a liquid storage cavity 10 separately, the liquid storage part 3 and the housing 1 are also sealed, so that the liquid storage cavity 10 is connected with the liquid discharge hole 12, and the fluid does not leak from the connection between the liquid storage part 3 and the housing 1. The liquid storage part 3 and the housing 1 are sealed in a manner such as directly sealing the two, such as by providing a sealing structure that cooperates with each other. Alternatively, a sealing member is sandwiched between the liquid storage part 3 and the housing 1, and the liquid storage part 3 and the housing 1 are sealed by the sealing member.

[0104] When the liquid storage part 3 and the case 1 together form the liquid storage cavity 10, the liquid storage part 3 and the case 1 also need to be sealed and connected. There are many ways of sealing connection. One optional way is that the liquid storage part 3 is directly sealed and connected to the case 1. Another way is that a seal is sandwiched between the liquid storage part 3 and the case 1, and the liquid storage part 3 and the case 1 are sealed and connected through the seal. The seal is, for example, a sealing ring. In the above implementation, the liquid storage part 3 is sealed and connected to the case 1, so that the liquid in the accommodating cavity 11 will not leak through the connection between the liquid storage part 3 and the case 1, thereby improving the performance of the battery pack.

[0105] As can be seen from the above description, when located outside the box body 1, the liquid storage portion 3 forms the liquid storage cavity 10 in two ways:

[0106] The first is that the liquid storage part 3 itself has a closed cavity structure, and the closed cavity has an inlet, and the inlet is connected to the drainage hole 12. The closed cavity serves as the liquid storage cavity 10. In the above technical solution, the liquid storage part 3 is a separate component, and the liquid storage cavity 10 is formed separately. During installation, the liquid storage part 3 is sealed and fixed to the box body 1, so that the liquid storage cavity 10 is connected to the drainage hole 12 to prevent liquid from leaking from the drainage hole 12 to the area outside the liquid storage cavity 10.

[0107] The second implementation manner is: the liquid storage portion 3 and the box body 1 together form a liquid storage cavity 10 .

[0108] See also Figure 1 and Fig.11 In some embodiments, the liquid storage part 3 is installed on the outer side of the wall 15 of the box body 1 with the drain hole 12, and is sealed and connected to the wall 15. The liquid storage part 3 and the outer side of the wall 15 form a liquid storage cavity 10.

[0109] When the liquid storage part 3 and the wall body 15 together form the liquid storage cavity 10, the sealing connection method between the liquid storage part 3 and the wall body 15 is similar to the sealing connection method described above. It will not be repeated here. In the above implementation method, the liquid storage part 3 is sealed and connected with the wall body 15, so that the liquid in the accommodating cavity 11 will not leak through the connection between the liquid storage part 3 and the wall body 15, thereby improving the performance of the battery pack.

[0110] Specifically, see Figure 1 , Figure 8 and Fig.11 The liquid storage portion 3 is provided with an inner recess 31 , and the inner recess 31 and the wall body 15 form a liquid storage cavity 10 .

[0111] In some embodiments, there are multiple inner recesses 31 , and the multiple inner recesses 31 together cover all the drainage holes 12 .

[0112] Alternatively, in some embodiments, the inner recess 31 is located outside all the drainage holes 12 , that is, the inner recess 31 completely covers all the drainage holes 12 , so that the liquid in the drainage holes 12 all flows into the liquid storage chamber 10 .

[0113] The number of the inner recesses 31 provided in one liquid storage part 3 is, for example, plural, and the multiple inner recesses 31 of the same liquid storage part 3 are connected or not connected.

[0114] In some embodiments, the liquid storage portion 3 is made of plastic. Plastic material has good deformation performance and can effectively absorb energy when impacted, thereby reducing the possibility of sealing failure.

[0115] In some embodiments, the volume of the liquid storage chamber 10 is greater than or equal to the volume of the coolant in the cooling system 22. The above arrangement ensures that when a serious leak occurs in the cooling system 22, the battery module 2 will not be immersed in the liquid, thereby increasing the safety of the battery pack.

[0116] See also Figures 1 to 9 In some embodiments, the liquid storage portion 3 further includes a protective portion 4, and the protective portion 4 is installed on a side of the liquid storage portion 3 away from the outer side.

[0117] The protection part 4 is, for example, a plate-like structure with a concave structure, which matches the concave part 31 of the liquid storage part 3 to completely wrap around the outside of the liquid storage part 3, thereby reducing the possibility of failure of the liquid storage part 3 due to collision.

[0118] The protection portion 4 is used to protect the liquid storage portion 3 to prevent the liquid storage portion 3 from being deformed and damaged due to impact.

[0119] In some embodiments, the strength of the protection part 4 is higher than that of the liquid storage part 3. The protection part 4 completely covers the liquid storage part 3.

[0120] See also Figures 12 to 16 Next, the specific implementation method of forming the liquid storage chamber 10 inside the box body 1 will be introduced.

[0121] See also Fig.12 and Fig.13 The box body 1 includes a box body 141 and a carrier 142 disposed inside the box body 141. The carrier 142 divides the internal space of the box body 1 into a receiving cavity 11 and a liquid storage cavity 10. The carrier 142 is provided with a drain hole 12, and the battery module 2 is mounted on the carrier 142.

[0122] The carrier 142 is, for example, in the shape of a plate. The carrier 142 is welded or bolted to the inner wall of the box body 1. The above structure makes the battery pack more compact and lighter.

[0123] The functions of the accommodating chamber 11 and the liquid storage chamber 10 are the same as those described above. The accommodating chamber 11 is used to install the battery module 2. The liquid storage chamber 10 is used to store the fluid leaked from the accommodating chamber 11. For other contents, please refer to the above description.

[0124] See also Fig.12 , Fig.13 and Fig.16 The bottom of the box body 1 is provided with a concave area 16, and the bearing member 142 is installed at the edge of the concave area 16. The concave area 16 is a part of the box body 1. The above arrangement simplifies the processing and makes the structure of the liquid storage chamber 10 stable and reliable.

[0125] See also Fig.12 A protective portion 4 is provided outside the liquid storage cavity 10 , and the protective portion 4 is used to cover the outer wall of the liquid storage cavity 10 .

[0126] The strength of the protection part 4 is, for example, higher than the strength of the outer wall of the liquid storage chamber 10. The protection part 4 is used to protect the outer wall of the liquid storage chamber 10 to reduce the possibility of leakage risk of the liquid storage chamber 10 in the event of a collision, etc., and ensure the normal use of the battery pack.

[0127] It can be understood that, in the above embodiments, as long as there is no contradiction, the relevant contents of the other embodiments can be referred to or combined to achieve that the liquid storage chamber 10 is partially located inside the box body 1 and partially located outside the box body 1.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery pack, characterized in that: include: A box body (1) comprising a containing cavity (11) and a liquid discharge hole (12) communicating with the containing cavity (11); and A battery module (2) is installed inside the accommodating cavity (11); Wherein, a liquid storage cavity (10) for storing liquid is provided below the battery module (2), and the liquid storage cavity (10) is communicated with the liquid discharge hole (12); The battery module (2) comprises: A battery cell assembly (21), comprising a plurality of battery cells (210) arranged side by side; and A cooling system (22), which abuts against the plurality of battery cells (210) and is used to cool each of the battery cells (210); Wherein, the drain hole (12) is used to discharge fluid leaked from the cooling system (22); The volume of the liquid storage chamber (10) is greater than or equal to the volume of the coolant in the cooling system (22); The opening size of one end of the liquid discharge hole (12) communicating with the accommodating cavity (11) is larger than the opening size of the other end communicating with the liquid storage portion (3); The liquid storage portion (3) is installed below a wall (15) of the box body (1) provided with the liquid discharge hole (12), and the liquid storage portion (3) is sealedly connected to the wall (15); wherein the liquid storage portion (3) and the wall (15) enclose the liquid storage cavity (10); The liquid storage portion (3) is provided with an inner recess (31) which is recessed in a direction away from the box body (1); There are a plurality of drainage holes (12), and the inner recess (31) is located outside all of the drainage holes (12) and covers all of the drainage holes (12).

2. The battery pack according to claim 1, characterized in that: Also includes: The protection portion (4) is mounted on a side of the liquid storage portion (3) away from the box body (1).

3. The battery pack according to claim 2, characterized in that: The hardness of the protective portion (4) is greater than the hardness of the liquid storage portion (3), and the protective portion (4) completely covers the liquid storage portion (3).

4. The battery pack according to any one of claims 1 to 3, characterized in that: The box (1) comprises: A first housing (13); and The second box body (14) and the first box body (13) enclose the accommodating cavity (11) and are located below the first box body (13); the liquid discharge hole (12) is provided in the second box body (14).

5. The battery pack according to claim 4, characterized in that: The second housing (14) comprises: Box body (141); and A carrier (142) is arranged inside the box body (141); the carrier (142) divides the internal space of the box body (1) into a containing cavity (11) and a liquid storage cavity (10); the carrier (142) is provided with the liquid discharge hole (12), and the battery module (2) is carried by the carrier (142).

6. The battery pack according to claim 5, characterized in that: The bottom of the box body (141) is provided with a concave area (16) that is recessed in a direction away from the first box body (13), and the bearing member (142) is connected to the edge of the concave area (16).

7. The battery pack according to claim 1, characterized in that: The cooling system (22) comprises: A cooling plate (221) having a cooling channel therein, and the number of the cooling plates (221) is more than two; and A connecting pipe (222) connected to the cooling plate (221) to connect the cooling channels of each cooling plate (221); Wherein, the drainage hole (12) is adjacent to the connection between the cooling plate (221) and the connecting pipe (222).

8. The battery pack according to claim 1, characterized in that: The battery cells (210) of the battery module (2) are arranged along the length direction of the box body (1), and the largest side surface of each battery cell (210) faces the wall (15) of the box body (1) where the drainage hole (12) is located.

9. The battery pack according to any one of claims 1 to 3, characterized in that: The drainage holes (12) are multiple and are arranged along the width direction of the box body (1).

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