Battery pack

Abstract

A battery pack, comprising: a die-cast housing (1), which has an accommodation cavity, wherein the accommodation cavity comprises a battery cell accommodation cavity (11) and a BMS accommodation cavity (12), the battery cell accommodation cavity (11) is provided with a battery cell opening (111), and the BMS accommodation cavity (12) is provided with a BMS opening (121); a battery cover (2), which is connected to the battery cell opening (111) in a sealed manner; a BMS cover (5), which is connected to the BMS opening (121) in a sealed manner; a battery module (3), which is assembled in the battery cell accommodation cavity (11), wherein the battery module (3) comprises at least two battery cells (311), and the battery cells (311) are stacked in the direction of the battery cell opening (111); and a BMS (4), which is assembled in the BMS accommodation cavity (12) and is electrically connected to the battery module (3). The battery pack structure can improve the balance and stability of the battery module, and enhance the strength and safety thereof.

Description

A battery pack

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 31, 2024, with application number 2024202418444. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of battery packs, and in particular to a battery pack. Background Art

[0003] In the related art, in order to achieve a lightweight design of a battery pack, the outer shell or cover is designed to be made of plastic or plastic material. Technical issues

[0004] Plastic or plastic shells or covers are prone to deformation and cracking under extrusion conditions, and cannot meet the safety requirements of automobiles under extreme conditions such as collision and extrusion. After the battery pack is squeezed, the CB (controlled drop) controllability of the battery pack is poor, which can easily lead to internal short circuits and fires in the battery pack. Technical Solutions

[0005] In the first aspect, the present application provides a battery pack, comprising: a die-cast shell, the die-cast shell having a accommodating cavity, the accommodating cavity including a battery cell accommodating cavity and a BMS accommodating cavity, the battery cell accommodating cavity being provided with a battery cell opening on a side away from the BMS accommodating cavity, and the BMS accommodating cavity being provided with a BMS opening on a side away from the battery cell accommodating cavity; a battery cover, the battery cover being sealed and connected to the battery cell opening; a BMS cover, the BMS cover being sealed and connected to the BMS opening; a battery module, the battery module being assembled in the battery cell accommodating cavity, the battery module comprising at least two battery cells, the battery cells being stacked along the direction of the battery cell opening; a BMS, the BMS being assembled in the BMS accommodating cavity and being electrically connected to the battery module. Beneficial effects

[0006] 1. Improve the balance and stability of the battery module: By stacking the battery cells in the battery module along the direction of the cell opening to form a horizontal arrangement, this design improves the balance and stability of the battery module compared to horizontally stacked battery modules, thereby making the battery module located in the die-cast shell safer and more resistant to shear.

[0007] 2. Meet the requirements of extrusion working conditions: Replacing the plastic shell with a die-cast shell improves the strength of the starting battery pack, thereby meeting the requirements of extrusion working conditions.

[0008] 3. Improved battery pack stability and balance: The internal cells are stacked horizontally, achieving better weight distribution and improving the stability and balance of the entire battery pack. This reduces structural issues caused by weight imbalance during use and improves the controllability of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 is a schematic diagram of the three-dimensional structure of an embodiment of the present application;

[0010] FIG2 is a schematic diagram of a partial explosion structure of an embodiment of the present application;

[0011] FIG3 is a schematic diagram of the back structure of the die-cast housing according to an embodiment of the present application;

[0012] FIG4 is a schematic diagram of the front structure of a die-cast housing according to an embodiment of the present application;

[0013] FIG5 is a schematic diagram of the assembly structure of the insulating die casting according to an embodiment of the present application;

[0014] FIG6 is a schematic diagram of the battery module structure of an embodiment of the present application;

[0015] FIG7 is a schematic diagram of the disassembled structure of the BMS cover body according to an embodiment of the present application.

[0016] The meanings of the reference numerals are as follows: 1. die-cast shell; 11. battery cell accommodating cavity; 111. battery cell opening; 112. second side wall; 113. stepped surface; 12. BMS accommodating cavity; 121. BMS opening; 122. first side wall; 123. plug; 124. dust plug; 13. partition plate; 131. wiring hole; 14. assembly part; 15. weight reduction groove; 2. battery cover; 3. battery module; 31. battery cell group; 311. battery cell; 32. first side wall; A first shell; 33, a second shell; 34, a filling piece; 35, a limiting piece; 36, a rib; 37, a first positive electrode connecting piece; 38, a first negative electrode connecting piece; 4, a BMS; 41, a second positive electrode connecting piece; 42, a second negative electrode connecting piece; 5, a BMS cover; 6, an insulating die-casting; 61, a first die-casting hole; 62, a first die-casting hole; 7, a first sealing layer; 71, a first clearance groove; 8, a second sealing layer; 81, a second clearance groove; 9, an auxiliary fixing piece. Modes for Carrying Out the Invention

[0017] Referring to Figures 1 to 7, the present application discloses a battery pack, including a die-cast shell 1, a battery cover 2, a BMS cover 5, a battery module 3 and a BMS 4. In one embodiment, the die-cast shell 1 has a accommodating cavity, and the accommodating cavity includes a battery cell accommodating cavity 11 and a BMS accommodating cavity 12. A battery cell opening 111 is provided on a side of the battery cell accommodating cavity 11 away from the BMS accommodating cavity 12, and a BMS opening 121 is provided on a side of the BMS accommodating cavity 12 away from the battery cell accommodating cavity 11, so that the battery cell opening 111 and the BMS opening 121 are arranged in opposite directions. The battery cover 2 It is sealed and connected to the battery cell opening 111, and the BMS cover 5 is sealed and connected to the BMS opening 121; the BMS cover 5 and the battery cover 2 are made of high-ductility sheet metal, have high strength and hardness, and can withstand large loads and impact forces, thereby improving the reliability and safety of the battery pack, the battery module 3 is assembled in the battery cell accommodating cavity 11, the battery module 3 includes at least two battery cells 311, and the battery cells 311 are stacked along the direction of the battery cell opening 111, and the BMS4 is assembled in the BMS accommodating cavity 12 and is electrically connected to the battery module 3. It is assumed that the battery cover 2 is assembled on the top surface of the die-cast shell 1, and the BMS cover 5 is assembled on the bottom surface of the die-cast shell 1. Therefore, the die-cast shell 1 can be divided into two layers, the upper and lower layers, which are respectively assembled with the battery module 3 and the BMS 4. At the same time, the battery cells 311 in the battery module 3 are stacked along the direction of the battery cell opening 111, that is, stacked longitudinally to form a horizontal arrangement. Compared with the horizontally stacked battery modules 3, the balance and stability of the battery module 3 are improved, so that the battery module 3 located in the die-cast shell 1 is safer and has stronger shear resistance.

[0018] In some embodiments, as shown in Figures 3-4 , to enhance the relative independence between the BMS 4 and the battery module 3, a partition 13 is provided between the cell accommodating cavity 11 and the BMS accommodating cavity 12. This partition 13 is provided with wiring holes 131. This allows the battery module 3 and the BMS 4 to be separated through the cell accommodating cavity 11 and the BMS accommodating cavity 12, thereby reducing the complexity of electrical connections and the probability of failure. Furthermore, the layered design provides enhanced protection, reducing the impact of the external environment on the BMS 4 and the modules, thereby improving CB controllability.

[0019] In some embodiments, referring to Figures 3-5, in order to reserve a certain assembly space between the BMS4 and the battery module 3, one side of the die-cast shell 1 is protruded outward to form an assembly portion 14, the battery cell accommodating cavity 11, the BMS accommodating cavity 12 and the partition plate 13 all extend toward the assembly portion 14, the wiring hole 131 is provided on the partition plate 13 in the assembly portion 14, the wiring hole 131 of the partition plate 13 is provided with an insulating die-casting 6, the battery module 3 is connected to a first positive electrode connecting piece 37 and a first negative electrode connecting piece 38, the BMS4 is connected to a second positive electrode connecting piece 41 and a second negative electrode The connecting piece 42, the insulating die-casting 6 includes a first die-casting hole 61 and a second die-casting hole. The first die-casting hole 61 is penetrated by a first connector, and the second die-casting hole is provided with a second connector. The first connector conducts and fixes the first positive electrode connecting piece 37 and the second positive electrode connecting piece 41, and the second connector conducts and fixes the first negative electrode connecting piece 38 and the second negative electrode connecting piece 42. They can be separated by the insulating die-casting 6, thereby improving the assembly stability between the BMS4 and the battery module 3, and the first connector and the second connector can be insulated and protected, thereby improving the wiring safety.

[0020] 5-6 , the battery module 3 is typically comprised of a cell group 31 and a plastic shell. To improve the safety of the battery module 3, in some embodiments, the battery module 3 includes a cell group 31, a first shell 32, and a second shell 33. The first shell 32 and the second shell 33 are both made of plastic. The cell group 31 is formed by stacking cells 311. The first shell 32 is sleeved onto one end of the cell group 31, and the second shell 33 is sleeved onto the other end of the cell group 31. A filler 34 is provided in the gap between the first shell 32 and the second shell 33, and the filler 34 abuts against the cell group 31. The filler 34 includes, but is not limited to, foam or structural adhesive. Specifically, in one embodiment, the filler 34 can be disposed between the cell group 31 and the bottom surface of the cell accommodating cavity 11, between the cell group 31 and the side surface of the cell accommodating cavity 11, or between the cell group 31 and the battery cover 2. The size of the filler 34 is not specifically limited. The cell group 31 between the first shell 32 and the second shell 33 can be completely or partially enclosed. Similarly, multiple fillers 34 can be designed as a single piece to simplify the installation process. It should be noted that to ensure the filling effect of the filler 34, the thickness of the filler 34 must be no less than the thickness of the first shell 32 and the second shell 33. The stacked cells 311 are enclosed and fixed by the first shell 32 and the second shell 33. The filler 34 can improve the compressive strength of the cell group 31 and reduce the impact, vibration, or pressure on the cell group 31. At the same time, the foam also provides insulation and heat dissipation, can position and fix the cell 311, provide better mechanical support, and thus improve the controllability of the CB.

[0021] In some embodiments, referring to FIG. 2 and FIG. 5 , a limiting member 35 is provided between the battery module 3 and the cell accommodating cavity 11, and the limiting member 35 is respectively against the battery module 3 and the cell accommodating cavity 11. The limiting member 35 can limit the position of the battery module 3 in the cell accommodating cavity 11, thereby achieving a fixing effect. In one embodiment, the limiting member 35 includes but is not limited to foam, structural glue or high elastic glue, and is used to fix the battery module 3 to at least three surfaces of the cell accommodating cavity 11, specifically the three surfaces away from the assembly portion 14. Since the first shell 32, the second shell 33 and the filler 34 of the battery module 3 are all made of flexible materials, the battery module 3 can be clamped into the cell accommodating cavity 11 as a whole in cooperation with the flexible limiting member 35, thereby achieving a fixing effect on the battery module 3.

[0022] In order to improve the clamping stability between the limiting member 35 and the battery module 3, in some embodiments, referring to Figure 6, a plurality of ribs 36 are provided on the outer surface of the first shell 32 and / or the second shell 33, and at least part of the ribs 36 abut against the limiting member 35. The arrangement direction of the ribs 36 can be horizontal or vertical, or staggered horizontally and vertically, which can increase the friction between the battery module 3 and the limiting member 35, thereby increasing the abutment strength between the first shell 32 and / or the second shell 33 and the limiting member 35 and improving the fixing effect.

[0023] In one embodiment, referring to Figures 3 and 7, the side wall of the BMS accommodating chamber 12 away from the assembly portion 14 is a first side wall 122. The first side wall 122 is provided with a hole, and a plug 123 for connecting to the BMS4 is provided in the hole. A sealing ring is provided between the plug 123 and the hole to ensure the sealing effect. A dust plug 124 is provided on the plug 123 to improve the airtightness of the plug 123 of the BMS accommodating chamber 12 and achieve a sealing and dust-proof effect. The side wall of the battery cell accommodating cavity 11 corresponding to the first side wall 122 is the second side wall 112. A step surface 113 is provided between the first side wall 122 and the second side wall 112. The width of the step surface 113 is the distance from the first side wall 122 to the second side wall 112. The length of the dust plug 124 after assembly with the plug 123 is less than the width of the step surface 113, which can reduce the impact of the die-cast shell 1 on the plug 123 when it is hit, thereby improving the safety of the plug 123.

[0024] In one embodiment, referring to Figures 2 and 7, a first sealing layer 7 is provided between the battery cover 2 and the battery cell opening 111, and a second sealing layer 8 is provided between the BMS cover 5 and the BMS opening 121, which can improve the assembly air tightness between the battery cover 2, the BMS cover 5 and the die-cast shell 1, and the first sealing layer 7 and the second sealing layer 8 include but are not limited to sealing rings or silicone pads; in some embodiments, the battery cell opening 111 is provided with a circle of first clearance grooves 71 corresponding to the first sealing layer 7, and / or, the BMS opening 121 is provided with a circle of second clearance grooves 81 corresponding to the second sealing layer 8. By providing the first clearance grooves 71 and the second clearance grooves 81, a better sealing effect can be provided for the first sealing layer 7 and the second sealing layer 8, so that the surface fit is closer, and the entry or leakage of substances such as gas, liquid or dust can be effectively prevented; at the same time, the first sealing layer 7 and the second sealing layer 8 can be provided with fixing and positioning functions to avoid movement or falling off during use, which helps to maintain the stability and durability of the seal. It should be noted that the first and second clearance grooves 71, 81 can be arcuate grooves corresponding to the sealing ring or rectangular grooves corresponding to the silicone pad, and this is not specifically limited in this embodiment. The BMS opening 121 and the battery cell opening 111 can adopt a curved structure to adapt to the different shapes of the BMS cover 5 and the battery cover 2, so that the battery cover 2 and the battery cell opening 111 are tightly fitted, and the BMS cover 5 and the BMS opening 121 are tightly fitted.

[0025] It should be noted that the battery cover 2 and the cell opening 111 are fastened and connected via fasteners, and the BMS cover 5 and the BMS opening 121 are fastened and connected via fasteners. These fasteners need to be located outside the first sealing layer 7 and the second sealing layer 8 to avoid damaging the sealing structure. In other embodiments, other assembly methods may be used instead of fasteners, and this embodiment does not specifically limit these.

[0026] In some embodiments, as shown in FIG1 , to reduce the overall weight of the battery pack, a plurality of weight-reducing grooves 15 are die-cast on the outer surface of the die-cast housing 1. These grooves 15 include, but are not limited to, triangular, rectangular, strip, or honeycomb-shaped grooves, which can reduce the weight of the die-cast housing 1 and reduce material usage while maintaining structural stability and load-bearing capacity. The grooves 15 can also provide a certain heat dissipation effect. Since the grooves 15 increase the surface area of ​​the die-cast housing 1, they help dissipate heat, thereby reducing the temperature of the battery pack and improving battery performance and lifespan.

[0027] In some embodiments, referring to Figures 1 and 7 , at least one auxiliary fixing member 9 is provided on the outer surface of the die-cast housing 1. In one embodiment, the auxiliary fixing members 9 include three, which are respectively screwed to the assembly portion 14 of the die-cast housing 1 and two side surfaces parallel to the assembly portion 14. It should be noted that the screws do not penetrate the die-cast housing 1 to avoid damaging the sealing structure of the die-cast housing 1. The shape of the auxiliary fixing members 9 is not specifically limited and can be assembled and fixed according to the actual space inside the car, which can improve the fixing effect of the die-cast housing 1 and meet the overall mechanical reliability and safety of the battery pack.

[0028] A starting battery pack, such as a 12V auxiliary lithium battery, is a type of battery pack that provides starting assistance, energy recovery, voltage stabilization, and emergency power supply. However, starting battery packs often utilize a combination of a soft case and a plastic shell, resulting in weak shear resistance. "Shear resistance" generally refers to the ability of a material or structure to resist shear forces. Shear force is a force acting on an object that attempts to cause relative displacement parallel to the direction of the force. Therefore, to improve shear resistance, all the structures described in the above embodiments can be transferred to the starting battery pack to enhance its shear resistance.

Claims

1. A battery pack comprising: A die-cast housing (1), the die-cast housing (1) having a housing cavity, the housing cavity comprising a cell housing cavity (11) and a BMS housing cavity (12), a cell opening (111) being provided on a side of the cell housing cavity (11) away from the BMS housing cavity (12), and a BMS opening (121) being provided on a side of the BMS housing cavity (12) away from the cell housing cavity (11); A battery cover (2), the battery cover (2) being sealed and connected to the battery cell opening (111); A BMS cover (5), the BMS cover (5) being sealed and connected to the BMS opening (121); A battery module (3), the battery module (3) being assembled in the battery cell accommodating cavity (11), the battery module (3) comprising at least two battery cells (311), the battery cells (311) being stacked along the direction of the battery cell opening (111); A BMS (4) is assembled in the BMS accommodating cavity (12) and is electrically connected to the battery module (3).

2. A battery pack according to claim 1, wherein: A partition plate (13) is provided between the battery cell accommodating chamber (11) and the BMS accommodating chamber (12), and a wiring hole (131) is provided on the partition plate (13).

3. A battery pack according to claim 1, wherein: The battery module (3) comprises: A battery cell group (31), wherein the battery cell group (31) is formed by stacking battery cells (311); a first casing (32), the first casing (32) being sleeved on one end of the battery cell group (31); a second casing (33), the second casing (33) being sleeved on the other end of the battery cell group (31); A filling piece (34) is provided in the gap between the first shell (32) and the second shell (33), and the filling piece (34) abuts against the battery cell group (31).

4. A battery pack according to claim 3, wherein: A limiting member (35) is provided between the battery module (3) and the battery cell accommodating cavity (11), and the limiting member (35) abuts against the battery module (3) and the battery cell accommodating cavity (11) respectively.

5. A battery pack according to claim 4, wherein: The outer surface of the first shell (32) and / or the second shell (33) is provided with a plurality of convex ribs (36), and at least part of the convex ribs (36) abuts against the limiting member (35).

6. The battery pack according to claim 1, wherein: A hole is provided on one side of the BMS accommodating chamber (12), a plug (123) for plugging with the BMS (4) is provided in the hole, and a dust plug (124) is provided on the plug (123).

7. A battery pack according to claim 6, wherein: The side wall of the BMS accommodating chamber (12) on which the hole is set is a first side wall (122), the side wall of the battery cell accommodating chamber (11) corresponding to the first side wall (122) is a second side wall (112), a stepped surface (113) is provided between the first side wall (122) and the second side wall (112), the width of the stepped surface (113) is the distance from the first side wall (122) to the second side wall (112), and the length of the dust plug (124) after assembly with the plug (123) is less than the width of the stepped surface (113).

8. The battery pack according to claim 1, wherein: A first sealing layer (7) is provided between the battery cover (2) and the battery cell opening (111), and a second sealing layer (8) is provided between the BMS cover (5) and the BMS opening (121).

9. A battery pack according to claim 8, wherein: The cell opening (111) is provided with a first clearance groove (71) around the first sealing layer (7), and / or the BMS opening (121) is provided with a second clearance groove (81) around the second sealing layer (8).

10. The battery pack according to claim 2, wherein: The wiring hole (131) of the partition plate (13) is provided with an insulating die-casting (6), the battery module (3) is connected with a first positive electrode connecting piece (37) and a first negative electrode connecting piece (38), the BMS (4) is connected with a second positive electrode connecting piece (41) and a second negative electrode connecting piece (42), the insulating die-casting (6) includes a first die-casting hole (61) and a second die-casting hole, the first die-casting hole (61) is penetrated by a first connector, the second die-casting hole is provided with a second connector, the first connector conducts and fixes the first positive electrode connecting piece (37) and the second positive electrode connecting piece (41), and the second connector conducts and fixes the first negative electrode connecting piece (38) and the second negative electrode connecting piece (42).

11. A battery pack according to any one of claims 1 to 10, wherein: A plurality of weight-reducing grooves (15) are die-cast on the outer surface of the die-cast housing (1).

12. A battery pack according to any one of claims 1 to 10, wherein: At least one auxiliary fixing member (9) is provided on the outer surface of the die-cast housing (1).

13. A battery pack according to any one of claims 1 to 10, wherein: The battery pack is a starting battery pack.

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