Battery cell fireproof structure and battery module

Abstract

The invention relates to the technical field of battery safety, and discloses a battery cell fireproof structure and a battery module, the battery cell fireproof structure comprises an end plate, a side plate and an epoxy plate, the end plate is arranged at the end part of a battery cell group; the side plate is arranged on the side surface of the battery cell group; two ends of the side plate are connected with the two end plates; the epoxy plate is mounted on the end plate; a through groove is formed in the side, close to the side plate, of the end plate, and the epoxy plate is attached to the side plate so that the projection, in the first direction, of the epoxy plate can cover the corresponding through groove. By arranging the epoxy plate, direct injection paths of high-temperature gas and particles are blocked by the epoxy plate, so that the high-temperature gas and the particles are not leaked, the external structure of the end plate is protected, a thermal runaway event is favorably limited between the end plate and the side plate, and the safety of the whole battery system is improved. The vent holes are formed in the side plates, so that high-pressure and high-temperature jet flows flow out, high-pressure explosion is prevented, an anaerobic environment is formed in the vent holes, oxygen is further prevented from entering, and the internal battery cell is prevented from exploding.

Description

Technical Field

[0001] This invention relates to the field of battery safety technology, specifically to a fireproof structure for battery cells and a battery module. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage industries, the safety performance of lithium batteries, as a core power source, has increasingly become a key focus of the industry. Among them, ternary lithium batteries have been widely used in electric vehicles and other fields due to their advantages such as high energy density and good low-temperature performance. However, ternary materials have poor stability at high temperatures and are prone to thermal runaway under conditions such as overcharging, short circuits, and mechanical abuse, releasing a large amount of heat and flammable gases. Improper handling can easily lead to fires or even explosions.

[0003] In existing air-cooled designs, ventilation channels are usually left inside the battery pack to ensure heat dissipation, and the module structure is also relatively open. This can lead to a large influx of external air when thermal runaway occurs, providing oxygen for the high-temperature ejected material, significantly increasing the risk of combustion, and even triggering a chain reaction of thermal spread. Summary of the Invention

[0004] In view of this, the present invention provides a fireproof structure for battery cells and a battery module to solve the problem that when thermal runaway occurs, a large amount of external air will rush in, providing oxygen to the high-temperature ejected material, significantly increasing the risk of combustion, and even causing a chain reaction of thermal spread.

[0005] In a first aspect, the present invention provides a fire-resistant structure for battery cells, applicable to battery cell assemblies, comprising:

[0006] End plate, the end plate being disposed at the end of the cell assembly; Side plate, the side plate is arranged on the side of the cell assembly, both ends of the side plate are connected to the two end plates, and the side plate is provided with ventilation holes; Epoxy board, the epoxy board being mounted on the end plate; The end plate has a through groove on the side closest to the side plate, and the epoxy board is attached to the side plate so that the projection of the epoxy board in the first direction covers its corresponding through groove.

[0007] Beneficial Effects: When a single cell in a battery pack experiences thermal runaway, a high-temperature jet is instantly generated. In traditional structures, the through-slots on the end plates easily allow oxygen to enter, leading to an explosion. This invention, by incorporating an epoxy plate whose projection covers the through-slots and whose body is tightly fitted to the side plate, blocks the high-temperature jet. The epoxy plate prevents the direct jetting path of high-temperature gas and particles, preventing leakage and protecting the external structure of the end plates. This helps confine the thermal runaway event between the end plates and side plates, improving the safety of the entire battery system. It also prevents oxygen from entering, avoiding internal cell explosions. Furthermore, vents are provided on the side plates for the high-pressure, high-temperature jet to escape, preventing high-pressure explosions. An anaerobic environment is created at the vent locations, further preventing oxygen from entering and avoiding internal cell explosions.

[0008] In one alternative implementation, the number of vent holes on each side plate is set to 6 to 8.

[0009] Beneficial effects: During normal operation of the battery pack, multiple vents provide sufficient effective ventilation area, ensuring uniform airflow to meet the heat dissipation needs of the cell assembly and preventing reduced heat dissipation efficiency and localized overheating due to insufficient vents. In extreme cases of thermal runaway, it avoids the potential for poor heat dissipation under normal operating conditions caused by complete sealing, effectively limits the rapid replenishment of oxygen during thermal runaway, suppresses the generation of open flames, and improves the controllability and safety of the entire system in the face of thermal runaway.

[0010] In an alternative embodiment, a top plate is further included, which is disposed at the top of the cell assembly and is sealed to both the end plate and the side plate.

[0011] In one alternative embodiment, the top plate is made of aluminum alloy.

[0012] In one alternative embodiment, a heat sink is provided on the top surface of the top plate away from the top surface of the battery cell assembly.

[0013] Beneficial effects: When the battery is working normally, the top plate is used for internal heat dissipation. In the event of thermal runaway, the top seal can effectively prevent high-temperature ejected material from spreading directly upwards without obstruction, further reducing the risk of external air seeping into the module from the top.

[0014] In a second aspect, the present invention also provides a battery module, comprising: at least two of the above-mentioned cell fireproof structures, wherein the at least two of the cell fireproof structures are arranged vertically in a stacked manner; It also includes a housing, within which a receiving cavity is provided, and the fireproof structure of the battery cell is fixed within the receiving cavity; There is a gap between the side plate and the side wall of the receiving cavity, and there is a gap between the top plate and the top surface of the receiving cavity.

[0015] In one alternative embodiment, at least two of the vent holes in the battery cell fireproof structure form a ventilation area; The battery module also includes a sealing strip, which is installed on the side plate; a plurality of sealing strips are provided, and the plurality of sealing strips are arranged on both sides of the ventilation area; The outer side of the sealing strip abuts against the side wall of the receiving cavity, and the two ends of the sealing strip are arranged corresponding to the two ends of the ventilation area.

[0016] In one optional embodiment, the outer casing is further provided with vent holes at both ends, and the vent holes are connected to the ventilation area through gaps.

[0017] Beneficial effects: In the event of thermal runaway, the large amount of hot, high-pressure gas generated first exits from its own vents and enters the gap between the side plate and the outer casing sidewall. Because the gaps on both sides of the venting area are blocked by sealing strips, this hot gas moves upwards, passes through the gap between the top plate and the top surface of the receiving cavity, and is then discharged from the exhaust port. This structure increases the flow path of the high-temperature gas before discharge and the contact time with the metal casing, which is beneficial for heat dissipation and cooling through the casing, preventing the direct discharge of high-temperature gas.

[0018] In one alternative embodiment, a rigid support member is also provided inside the sealing strip.

[0019] Beneficial effects: The rigid support provides an internal skeleton for the sealing strip, which can effectively resist excessive compression deformation and ensure that the sealing strip maintains the preset shape and appropriate compression throughout its life cycle, thereby maintaining stable and reliable airtightness.

[0020] In one alternative embodiment, a heat insulation pad is placed between two adjacent fireproof cell structures. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is the overall structure of a battery cell assembly with a fire-resistant cell structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the through-slot structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the battery module structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the sealing strip and heat insulation pad according to an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1. Battery cell assembly; 2. End plate; 21. Through slot; 3. Side panel; 31. Ventilation hole; 4. Epoxy board; 5. Top slab; 6. Outer casing; 61. Vent hole; 7. Sealing strip; 8. Heat insulation pad. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] With the rapid development of new energy vehicles and energy storage industries, the safety performance of lithium batteries, as a core power source, has increasingly become a key focus of the industry. Among them, ternary lithium batteries have been widely used in electric vehicles and other fields due to their advantages such as high energy density and good low-temperature performance. However, ternary materials have poor stability at high temperatures and are prone to thermal runaway under conditions such as overcharging, short circuits, and mechanical abuse, releasing a large amount of heat and flammable gases. Improper handling can easily lead to fires or even explosions.

[0025] In existing air-cooled designs, ventilation channels are usually left inside the battery pack to ensure heat dissipation, and the module structure is also relatively open. This can lead to a large influx of external air when thermal runaway occurs, providing oxygen for the high-temperature ejected material, significantly increasing the risk of combustion, and even triggering a chain reaction of thermal spread.

[0026] To solve the above technical problems, the following will be combined with... Figures 1 to 4 The following describes embodiments of the present invention.

[0027] According to an embodiment of the present invention, a fire-resistant structure for battery cells is provided, applicable to battery cell assembly 1. The fire-resistant structure mainly includes an end plate 2, a side plate 3, and an epoxy board 4. The first direction is the length direction of the battery cell assembly 1.

[0028] like Figure 1 and Figure 2As shown, there are two end plates 2, which are fixedly installed at the two ends of the battery cell assembly 1 along its length. The end plates 2 are usually made of metal and provide end constraints and structural support for the battery cell assembly 1. There are two side plates 3, which are respectively arranged on the two sides of the battery cell assembly 1. The two ends of the side plates 3 are fixedly connected to the corresponding ends of the two end plates 2, thus forming a stable frame together with the two end plates 2 to constrain the battery cell assembly 1. Vent holes 31 may be provided on the side plates 3. Near the side plates 3, the end plates 2 are also provided with through grooves 21 corresponding to the copper busbars on the battery cell assembly 1 and the nuts that fix the copper busbars.

[0029] like Figure 1 and Figure 2 As shown, two epoxy boards 4 are installed on each end plate 2. The epoxy boards 4 are provided with copper busbars and inlet / outlet ports for the acquisition lines. The epoxy boards 4 are made of epoxy resin. The epoxy boards 4 are fixed to the end plate 2. After installation, the epoxy boards 4 are tightly attached to the end surfaces of the adjacent side plates 3. In this embodiment, the area of ​​the epoxy boards 4 is increased so that the orthographic projection of the epoxy boards 4 in the plane along the first direction completely covers the through groove 21 on the corresponding end plate 2.

[0030] When a single cell in cell assembly 1 experiences thermal runaway, a high-temperature jet is instantly generated. In traditional structures, the through-slot 21 on end plate 2 easily allows oxygen to enter, leading to an explosion. In this invention, an epoxy plate 4 is installed, with its projection covering the through-slot 21. The epoxy plate 4 is tightly fitted to the side plate 3. When the high-temperature jet is blocked by the epoxy plate 4, it prevents the direct jetting path of high-temperature gas and particles, thus protecting the external structure of end plate 2 and helping to confine the thermal runaway event between end plate 2 and side plate 3, improving the safety of the entire battery system. It also prevents oxygen from entering, avoiding internal cell explosions. Furthermore, a vent 31 is provided on the side plate 3 for the high-pressure, high-temperature jet to flow out, preventing high-pressure explosions. An anaerobic environment is also created at the vent 31 location, further preventing oxygen from entering and avoiding internal cell explosions.

[0031] In one embodiment, such as Figure 1 and Figure 4 As shown, each side plate 3 has multiple ventilation holes 31 for air circulation. Specifically, there are six to eight holes; in this embodiment, there are six holes, arranged in two rows, with three ventilation holes 31 in each row.

[0032] When the battery pack is operating normally, the multiple vents 31 provide sufficient effective ventilation area to ensure uniform airflow and meet the heat dissipation requirements of the cell assembly 1, avoiding reduced heat dissipation efficiency and localized overheating due to insufficient vents. In the extreme case of thermal runaway, this not only avoids poor heat dissipation under normal operating conditions that might result from complete sealing, but also effectively limits the rapid replenishment of oxygen during thermal runaway, suppresses the generation of open flames, and improves the controllability and safety of the entire system in dealing with thermal runaway.

[0033] In one embodiment, such as Figures 1 to 4 As shown, the fireproof structure of the battery cell also includes a top plate 5. The top plate 5 is located at the top of the battery cell assembly 1, covering the upper surface of the battery cell assembly 1. The four edges of the top plate 5 are sealed to the tops of the two end plates 2 and the tops of the side plates 3, respectively. The top plate 5, end plates 2, and side plates 3 together form a more enclosed module space. The top plate 5 is made of aluminum alloy. Several heat sinks are provided on the top surface of the top plate 5 away from the battery cell assembly 1 to increase the heat exchange area between the top plate 5 and the outside air.

[0034] When the battery is working normally, the top plate 5 is used for internal heat dissipation. In the event of thermal runaway, the top seal can effectively prevent high-temperature ejected material from spreading directly upwards without obstruction, further reducing the risk of external air seeping into the module from the top.

[0035] According to an embodiment of the present invention, in another aspect, a battery module is also provided, such as... Figure 3 and Figure 4 As shown, it includes a housing 6, which is a rectangular housing 6. Figure 3 For ease of observation of the battery cell assembly 1 and the fire-resistant battery cell structure, the top and front faces are not shown. At least two fire-resistant battery cell structures are arranged vertically in a stacked configuration. An internal receiving cavity is provided within the outer casing 6, within which the stacked battery cell assembly 1 and the fire-resistant battery cell structure are installed and fixed as a whole, with their bottoms fixed to the receiving cavity. A predetermined gap exists between the side plate 3 and the corresponding side wall of the receiving cavity, and a gap also exists between the side plate 3 and the inner side wall of the outer casing 6. Similarly, a predetermined gap exists between the top plate 5 and the top surface of the receiving cavity.

[0036] Since each battery cell group 1 has a vent hole 31 on its side plate 3, when multiple battery cell groups 1 are vertically stacked and aligned, these corresponding vent holes 31 together form a continuous, strip-shaped ventilation area on the plane of the side plate 3.

[0037] like Figure 4As shown, the battery module also includes sealing strips 7, which are made of high-temperature resistant elastic material and are installed on the side plate 3 of the fireproof structure. Specifically, several sealing strips 7 are provided; in this embodiment, four are provided, with two sealing strips 7 corresponding to each ventilation area. They are arranged on the left and right sides of the ventilation area, with each sealing strip 7 vertically positioned. The outer side of each sealing strip 7 facing away from the side plate 3 abuts against the side wall of the receiving cavity, thereby forming an isolation strip in the gap between the side plate 3 and the side wall of the outer casing 6. The two ends of each sealing strip 7 in the vertical direction are arranged corresponding to the two ends of the ventilation area in the vertical direction. Vent holes 61 are also provided at both ends of the outer casing 600. The vent holes 61 are connected to the internal space of the outer casing 6 and the aforementioned gap.

[0038] When thermal runaway occurs, the large amount of hot, high-pressure gas generated is first ejected from its own vent 31 and enters the gap between the side plate 3 and the side wall of the outer casing 6. Because the gaps on both sides of the venting area are blocked by the sealing strip 7, this hot gas moves upward, passes through the gap between the top plate 5 and the top surface of the receiving cavity, and is then discharged from the exhaust port. This structure increases the flow path of the high-temperature gas before discharge and the contact time with the metal outer casing 6, which is beneficial for heat dissipation and cooling through the outer casing 6, preventing the direct discharge of high-temperature gas.

[0039] In one embodiment, such as Figure 4 As shown, a rigid support element is also embedded inside the sealing strip 7. For example, a stainless steel sheet or an aluminum alloy sheet. The rigid support element provides an internal skeleton for the sealing strip 7, which can effectively resist excessive compression deformation and ensure that the sealing strip 7 maintains the preset shape and appropriate compression throughout its entire lifespan, thereby maintaining stable and reliable airtightness.

[0040] In one embodiment, a heat insulation pad 8 is placed between two adjacent fireproof cell structures. The heat insulation pad 8 can effectively block or significantly reduce the conduction of heat from the hotter lower cell to the upper cell, which helps to achieve independent management of the temperature of each cell layer and a more uniform overall temperature distribution, and avoids heat accumulation at the top.

[0041] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A fire-resistant structure for battery cells, suitable for battery cell assemblies (1), characterized in that, include: End plate (2), the end plate (2) is disposed at the end of the cell assembly (1); Side plate (3), the side plate (3) is arranged on the side of the battery cell assembly (1), both ends of the side plate (3) are connected to the two end plates (2), and the side plate (3) is provided with ventilation holes (31). Epoxy board (4), the epoxy board (4) is mounted on the end plate (2); The end plate (2) is provided with a through groove (21) on the side of the side plate (3), and the epoxy board (4) is attached to the side plate (3) so that the projection of the epoxy board (4) in the first direction covers its corresponding through groove (21).

2. The fireproof structure for battery cells according to claim 1, characterized in that, The number of vents (31) on each of the side plates (3) is set to 6 to 8.

3. The fireproof structure for the battery cell according to claim 1, characterized in that, It also includes a top plate (5), which is arranged at the top of the cell assembly (1), and the top plate (5) is sealed to the end plate (2) and the side plate (3).

4. The fireproof structure for the battery cell according to claim 3, characterized in that, The top plate (5) is made of aluminum alloy.

5. The fireproof structure for the battery cell according to claim 4, characterized in that, The top plate (5) has heat sinks on its top surface away from the battery cell assembly (1).

6. A battery module, characterized in that, The battery cell fireproof structure includes at least two of the battery cell fireproof structures as described in any one of claims 3-5, wherein at least two of the battery cell fireproof structures are arranged in a vertically stacked manner; It also includes a housing (6), in which a receiving cavity is provided, and the fireproof structure of the battery cell is fixed in the receiving cavity; There is a gap between the side plate (3) and the side wall of the receiving cavity, and there is a gap between the top plate (5) and the top surface of the receiving cavity.

7. The battery module according to claim 6, characterized in that, At least two of the vent holes (31) in the fireproof structure of the battery cell form a ventilation area; The battery module also includes a sealing strip (7), which is installed on the side plate (3); a plurality of sealing strips (7) are provided, and the plurality of sealing strips (7) are arranged on both sides of the ventilation area; The outer side of the sealing strip (7) abuts against the side wall of the receiving cavity, and the two ends of the sealing strip (7) are arranged corresponding to the two ends of the ventilation area.

8. The battery module according to claim 7, characterized in that, The outer casing (6) is also provided with exhaust holes (61) at both ends, and the exhaust holes (61) are connected to the ventilation area through gaps.

9. The battery module according to claim 7, characterized in that, The sealing strip (7) is also provided with a rigid support.

10. The battery module according to claim 7, characterized in that, A heat insulation pad (8) is placed between two adjacent fireproof structures of the battery cells.

Images