Cylindrical battery module and battery pack

Abstract

The embodiment of the utility model provides a cylindrical battery module and a battery pack, and relates to the field of cylindrical batteries. The problems that a cylindrical battery cell cannot resist external impact, and thermal runaway cannot be considered in the heat preservation and heat insulation design are solved. The cylindrical battery module comprises a plurality of cylindrical battery cells and a first pouring sealant, and the plurality of cylindrical battery cells are arranged in an array; the first pouring sealant is poured at the bottoms of the plurality of cylindrical battery cells, and the first pouring sealant is in contact with the bottom surfaces of the plurality of cylindrical battery cells at the same time. The battery pack comprises the cylindrical battery module, pouring sealant is arranged at the bottom of the battery cell, the problems of liquid leakage, deformation, short circuit and the like caused by collision of the battery cell on the bottom plate can be effectively prevented, meanwhile, heat preservation and thermal runaway protection can be carried out on the battery cell module, and safe use of the lithium battery is facilitated.

Description

Technical Field

[0001] The utility model relates to the field of cylindrical batteries, and in particular to a cylindrical battery module and a battery pack. Background Art

[0002] Lithium batteries are the energy core of electric vehicles, providing power for electric vehicles. The power battery system is generally installed at the bottom of the vehicle, and the current large cylindrical batteries (4695, 4680, 46110, etc.) are generally placed vertically due to the structural design characteristics, and the bottom of the battery is close to the bottom plate. When the chassis of an electric vehicle encounters a slight bump, it generally does not have a significant impact, mainly because the chassis of the car was designed with impact resistance in mind at the beginning and can withstand a certain degree of external impact; but if the bump is more serious, key components such as the power battery system will be damaged, affecting the battery, which may cause serious consequences such as battery leakage, deformation, and short circuit.

[0003] In addition, judging from the current development trend of battery systems, more and more designs are using liquid cooling systems, so the thermal insulation design of the box module is becoming more and more important, but the thermal insulation design must not affect the thermal runaway protection design of the entire package. Utility Model Content

[0004] The purpose of the utility model includes, for example, providing a cylindrical battery module, which can improve the problem that the cylindrical battery core cannot resist external impact and the thermal insulation design cannot take into account thermal runaway.

[0005] The purpose of the utility model also includes providing a battery pack that can improve the problem that cylindrical batteries cannot resist external impacts and that thermal insulation design cannot take into account thermal runaway.

[0006] The embodiments of the present invention can be implemented as follows:

[0007] An embodiment of the utility model provides a cylindrical battery module, comprising a plurality of cylindrical battery cells and a first potting glue, wherein the plurality of cylindrical battery cells are arranged in an array; the first potting glue is potted at the bottom of the plurality of cylindrical battery cells, and the first potting glue is in contact with the bottom surfaces of the plurality of cylindrical battery cells at the same time.

[0008] In addition, the cylindrical battery module provided by the embodiment of the utility model may also have the following additional technical features:

[0009] Optionally, the cylindrical battery module also includes a plastic part; the plastic part is provided with a plurality of battery cell slots, and the bottoms of the plurality of battery cell slots are respectively provided with hollow holes; the plurality of cylindrical battery cells are respectively fixed in the plurality of battery cell slots, and the bottom surfaces of the plurality of cylindrical battery cells respectively correspond to the hollow holes; the first potting glue is potted in the hollow holes, and the first potting glue is in contact with the bottom surfaces of the battery cells.

[0010] Optionally, the first potting glue is potted at the bottom of the plastic component, and the first potting glue is in sealing contact with the bottom surface of the battery cell through the hollow hole.

[0011] Optionally, the first potting compound includes a plurality of molded contact parts and a covering layer; the plurality of contact parts are sealed in contact with the bottom surfaces of the plurality of cylindrical battery cells through the hollow holes respectively, and the covering layer is simultaneously connected to the plurality of contact parts and pots the bottom of the plastic part.

[0012] Optionally, the cross-section of the contact portion and the covering layer along the axial direction of the cylindrical battery core is in a convex shape.

[0013] Optionally, the cylindrical battery module further includes a second potting glue; the second potting glue is potted on the top of the plurality of cylindrical batteries, and the second potting glue is in contact with the top surfaces of the plurality of cylindrical battery cells at the same time.

[0014] Optionally, the cylindrical battery cell is a large cylindrical battery cell.

[0015] Optionally, an explosion-proof valve is provided on the bottom surface of the cylindrical battery cell.

[0016] The embodiment of the utility model further provides a battery pack, which includes a housing and a cylindrical battery module; the cylindrical battery module is arranged in the housing.

[0017] Optionally, the shell includes a battery pack bottom plate, and the battery pack bottom plate is arranged at the bottom of the first potting glue.

[0018] The cylindrical battery module and battery pack of the present utility model have the following beneficial effects, for example:

[0019] A cylindrical battery module comprises a plurality of cylindrical battery cells and a first potting glue, wherein the plurality of cylindrical battery cells are arranged in an array; the first potting glue is potted at the bottom of the plurality of cylindrical battery cells, and the first potting glue is in contact with the bottom surfaces of the plurality of cylindrical battery cells at the same time.

[0020] In a limited space, the impact of the external environment temperature on the battery cells and electrical performance inside the battery box is reduced or even isolated, and a reasonable operating temperature is maintained, thereby maximizing the performance of the battery and extending the battery life. When the battery cell has thermal runaway, it can play a heat insulation role, delaying or blocking the accident; when the battery cell overheats and burns, it can effectively block or delay the spread of the fire, providing enough time for escape and rescue work.

[0021] The battery pack, including the above-mentioned cylindrical battery module, can improve the problem that the cylindrical battery cell cannot resist external impact and the thermal insulation design cannot take into account thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the structure of a cylindrical battery module provided in this embodiment without being filled with the first potting glue;

[0024] Figure 2 A schematic diagram of the structure of the cylindrical battery module provided in this embodiment for encapsulating the first encapsulating glue;

[0025] Figure 3 A schematic diagram of a simulation of a cylindrical battery cell in a cylindrical battery module provided in this embodiment being hit by a foreign object;

[0026] Figure 4 A schematic diagram of the internal structure of a cylindrical battery module provided in this embodiment;

[0027] Figure 5 A schematic diagram of the structure of thermal runaway of a cylindrical battery module provided in this embodiment.

[0028] Icons: 10-cylindrical battery module; 100-cylindrical battery cell; 200-plastic part; 210-battery cell slot; 211-hollow hole; 300-first potting glue; 310-contact part; 320-covering layer; 400-second potting glue; 11-battery pack bottom plate; 30-impact with foreign objects. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0032] In the description of the present utility model, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the utility model product is usually placed when used. It is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present utility model.

[0033] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0034] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0035] Combine the following Figures 1 to 5 The cylindrical battery module 10 provided in this embodiment is described in detail.

[0036] Please refer to Figure 1 , Figure 2 and Figure 3 An embodiment of the utility model provides a cylindrical battery module 10, including a plurality of cylindrical battery cells 100 and a first potting glue 300, wherein the plurality of cylindrical battery cells 100 are arranged in an array; the first potting glue 300 is potted at the bottom of the plurality of cylindrical battery cells 100, and the first potting glue 300 is in contact with the bottom surfaces of the plurality of cylindrical battery cells 100 at the same time.

[0037] The first potting glue 300 also refers to the potting glue. The first potting glue 300 is used to distinguish the second potting glue 400 mentioned below. The first potting glue 300 and the second potting glue 400 are set at different positions and are made of the same material.

[0038] Figure 1 The figure shows that the cylindrical battery cell 100 module is completed, and there is no potting glue at the bottom of the cylindrical battery cell 100; Figure 2 The figure shows the state of applying potting glue on the bottom of the cylindrical battery cell 100. During the operation of the vehicle, since the battery pack is generally located at the chassis position and close to the ground, when the collision is serious, foreign objects may pierce the cylindrical battery cell 100. The cylindrical battery cell 100 contains a large amount of electrolyte, which will contaminate the battery pack after leakage.

[0039] The first potting glue 300 is potted at the bottom of the cylindrical battery cell 100, and has a buffering effect, which can effectively prevent leakage, deformation and short circuit caused by the battery cell colliding with the bottom plate; at the same time, when the electrolyte leaks, the first potting glue 300 can react with the electrolyte, absorb the electrolyte, avoid contaminating other structural parts of the battery pack, and play an insulating and protective role; in addition, the first potting glue 300 has a heat preservation and heat insulation effect. The heat preservation makes the temperature of the cylindrical battery cell 100 drop slowly, and the heat insulation reduces the external heat conduction efficiency. In a limited space, it reduces or even isolates the influence of the external ambient temperature on the cylindrical battery cell 100 and the electrical performance, maintains a reasonable operating temperature, maximizes the battery performance, and prolongs the battery life; in addition, when thermal runaway occurs, under the influence of high temperature and hot air flow, the potting glue at the bottom of the battery cell is heated and powdered. Since the strength of the potting glue itself is also low, it does not affect the release of the mass flow of the battery cell during thermal runaway. At the same time, the potting glue of other battery cells is not affected, which can block the thermal or electrical short circuit caused by the mass flow of the thermal runaway battery cell.

[0040] In this embodiment, the cylindrical battery cell 100 is a large cylindrical battery cell 100. The large cylindrical battery cell 100, for example, is 4695, 4680, 46110, etc. The first potting glue 300 is suitable for bottom protection of various types of cylindrical battery cells 100.

[0041] Reference Figure 3 In this embodiment, an explosion-proof valve is provided on the bottom of the cylindrical battery cell 100. When there is potting glue at the bottom of the battery cell explosion-proof valve, the potting glue is elastic and impact-resistant. On the one hand, it can reduce the impact of the foreign body 30 on the battery cell, and on the other hand, it can react with the leaked electrolyte to avoid contaminating the battery pack, and at the same time play an insulating role to reduce the risk of short circuit.

[0042] Reference Figure 3 In this embodiment, the cylindrical battery module 10 further includes a plastic part 200; the plastic part 200 is provided with a plurality of battery cell grooves 210, and the bottoms of the plurality of battery cell grooves 210 are respectively provided with hollow holes 211; the plurality of cylindrical battery cells 100 are respectively fixed in the plurality of battery cell grooves 210, and the bottom surfaces of the plurality of cylindrical battery cells 100 respectively correspond to the hollow holes 211; the first potting glue 300 is potted in the hollow holes 211, and the first potting glue 300 is in contact with the bottom surface of the battery cell.

[0043] The cell slot 210 on the plastic part 200 is used to install the cylindrical cell 100. The cell slot 210 is cylindrical, and a hollow hole 211 is provided at the bottom of the cell slot 210. The bottom surface of the cylindrical cell 100 is exposed through the hollow hole 211. The first potting glue 300 is potted into the hollow hole 211 to pot the bottom surface of the cylindrical cell 100 to play a protective role.

[0044] Reference Figure 3In this embodiment, the first potting glue 300 is potted at the bottom of the plastic part 200, and the first potting glue 300 is in sealing contact with the bottom surface of the battery cell through the hollow hole 211. The first potting glue 300 is not only potted into the hollow hole 211, but also potted into the bottom of the entire cylindrical battery module 10, and multiple cylindrical battery cells 100 are potted at the same time.

[0045] Reference Figure 3 In this embodiment, the first potting compound 300 includes a plurality of molded contact portions 310 and a covering layer 320 ; the plurality of contact portions 310 are respectively in sealing contact with the bottom surfaces of the plurality of cylindrical battery cells 100 through the hollow holes 211 , and the covering layer 320 is simultaneously connected to the plurality of contact portions 310 and pots the bottom of the plastic part 200 .

[0046] After the hollow holes 211 and the bottoms of the plurality of cylindrical battery cells 100 are potted, a plurality of contact portions 310 distributed at intervals are formed on the surface of the cover layer 320 . The contact portions 310 are potting glue formed in the hollow holes 211 .

[0047] Reference Figure 3 In this embodiment, the cross-section of the contact portion 310 and the cover layer 320 along the axial direction of the cylindrical battery cell 100 is in a "convex" shape. The bottom surface of the cylindrical battery cell 100 and the portion between the cylindrical battery cells 100 are potted and sealed to enhance the protection effect.

[0048] Reference Figure 3 and Figure 4 In this embodiment, the cylindrical battery module 10 further includes a second potting glue 400 ; the second potting glue 400 is potted on the top of the plurality of cylindrical batteries, and the second potting glue 400 is in contact with the top surfaces of the plurality of cylindrical battery cells 100 at the same time.

[0049] The top of the cylindrical battery cell 100 is the positive electrode, and the bottom of the cylindrical battery cell 100 is the negative electrode. The positive electrode and the negative electrode of the cylindrical battery cell 100 are both potted with potting glue, and the positive and negative electrodes of the cylindrical battery cell 100 are protected at the same time.

[0050] According to a cylindrical battery module 10 provided in this embodiment, the working principle of the cylindrical battery module 10 is:

[0051] When the collision is more serious, foreign objects may pierce the battery cell. The battery cell contains a large amount of electrolyte, which will contaminate the battery pack after leakage. When there is potting glue at the bottom of the battery cell explosion-proof valve, the potting glue is elastic and impact-resistant. On the one hand, it can reduce the impact of the impact on the battery cell, and on the other hand, it can react with the leaked electrolyte to avoid contaminating the battery pack. At the same time, it plays an insulating role and reduces the risk of short circuit.

[0052] Under normal circumstances, the top and bottom of the cylindrical module battery cell will be in direct contact with the air. There are structural parts around the module to block the battery cell from direct contact with the air. In addition, the application of liquid cooling system will also cause poor insulation effect of the module. Therefore, potting glue is applied to the bottom and top of the module battery cell to increase thermal resistance, reduce module heat dissipation, and achieve insulation function.

[0053] When thermal runaway occurs in the battery cell, the potting glue at the positive and negative ends of the battery cell will be powderized by the heat under the influence of high temperature and hot air flow. Since the strength of the potting glue itself is also low, it will not affect the release of mass flow during thermal runaway of the battery cell. At the same time, the potting glue of the positive and negative electrodes of other battery cells will not be affected, which can block the thermal or electrical short circuit caused by the mass flow of the thermal runaway battery cell.

[0054] The cylindrical battery module 10 provided in this embodiment has at least the following advantages:

[0055] Bottom collision protection function: the potting glue at the bottom of the battery cell can be compressed to a certain extent to prevent the battery cell from being squeezed by hard objects at the bottom. At the same time, the potting glue is insulated and non-conductive, which can isolate short circuits caused by collision objects.

[0056] Insulation function: The potting glue has low thermal conductivity. After covering the surface of the battery cell, it achieves physical isolation between the battery cell and the air, slowing down the cooling speed;

[0057] Electrolyte leakage protection: the cylindrical battery cell 100 may leak electrolyte during use. Potting glue is added to the positive and negative electrodes of the battery cell. When the electrolyte leaks, it can react chemically with the potting glue to absorb the electrolyte, thereby avoiding contamination of other battery cells and structural parts.

[0058] Thermal runaway protection: When a battery cell experiences thermal runaway, the potting glue at both ends of the battery cell will be powderized by heat under the influence of high temperature and hot air flow. Since the strength of the potting glue itself is also low, it will not affect the release of mass flow during thermal runaway of the battery cell. At the same time, the positive and negative electrodes of other normal battery cells are protected by potting glue and are not affected by the mass ejected from the runaway battery cell, thus playing a role of heat insulation and insulation protection, avoiding thermal or electrical short circuits caused by the mass flow of the thermal runaway battery cell.

[0059] The embodiment of the utility model also provides a battery pack. The battery pack includes a shell and a cylindrical battery module 10; the cylindrical battery module 10 is arranged in the shell. The first potting glue 300 and the second potting glue 400 are potted on the top and bottom of the cylindrical battery module 10, located in the shell, and play a role in heat insulation and thermal runaway protection.

[0060] In this embodiment, the housing includes a battery pack bottom plate 11, and the battery pack bottom plate 11 is disposed at the bottom of the first potting glue 300. The bottom of the cylindrical battery cell 100 corresponds to the bottom plate of the battery pack, and the first potting glue 300 is disposed at the bottom of the cylindrical battery cell 100, which has a good protective effect and effectively improves the problem that the cylindrical battery cell 100 cannot resist external impact and the thermal insulation design cannot take into account thermal runaway.

[0061] The above are only specific implementations of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A cylindrical battery module, characterized in that: include: A plurality of cylindrical battery cells (100), wherein the plurality of cylindrical battery cells (100) are arranged in an array; and a first potting glue (300), wherein the first potting glue (300) is potted at the bottom of the plurality of cylindrical battery cells (100), and the first potting glue (300) is in contact with the bottom surfaces of the plurality of cylindrical battery cells (100) at the same time.

2. The cylindrical battery module according to claim 1, characterized in that: The cylindrical battery module further comprises a plastic part (200); the plastic part (200) is provided with a plurality of battery cell grooves (210), and the bottoms of the plurality of battery cell grooves (210) are respectively provided with hollow holes (211); the plurality of cylindrical battery cells (100) are respectively fixed in the plurality of battery cell grooves (210), and the bottom surfaces of the plurality of cylindrical battery cells (100) respectively correspond to the hollow holes (211); the first potting glue (300) is potted in the hollow holes (211), and the first potting glue (300) is in contact with the bottom surfaces of the battery cells.

3. The cylindrical battery module according to claim 2, characterized in that: The first potting glue (300) is potted on the bottom of the plastic part (200), and the first potting glue (300) is in sealing contact with the bottom surface of the battery cell through the hollow hole (211).

4. The cylindrical battery module according to claim 3, characterized in that: The first potting glue (300) comprises a plurality of molded contact parts (310) and a covering layer (320); the plurality of contact parts (310) are in sealing contact with the bottom surfaces of the plurality of cylindrical battery cells (100) through the hollow holes (211), respectively, and the covering layer (320) is simultaneously connected to the plurality of contact parts (310) and pots the bottom of the plastic part (200).

5. The cylindrical battery module according to claim 4, characterized in that: The cross-section of the contact portion (310) and the covering layer (320) along the axial direction of the cylindrical battery core (100) is in a "convex" shape.

6. The cylindrical battery module according to any one of claims 1 to 5, characterized in that: The cylindrical battery module further comprises a second potting glue (400); the second potting glue (400) is potted on the top of the plurality of cylindrical batteries, and the second potting glue (400) is in contact with the top surfaces of the plurality of cylindrical battery cells (100) at the same time.

7. The cylindrical battery module according to any one of claims 1 to 5, characterized in that: The cylindrical battery core (100) is a large cylindrical battery core (100).

8. The cylindrical battery module according to claim 7, characterized in that: An explosion-proof valve is provided on the bottom surface of the cylindrical battery core (100).

9. A battery pack, characterized in that: The battery pack comprises a shell and a cylindrical battery module according to any one of claims 1 to 8; the cylindrical battery module is arranged in the shell.

10. The battery pack according to claim 9, characterized in that: The housing comprises a battery pack bottom plate (11), and the battery pack bottom plate (11) is arranged at the bottom of the first potting glue (300).

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