Blade battery, battery module, and battery pack

Abstract

The present application relates to the technical field of batteries, and discloses a blade battery, a battery module, and a battery pack. The battery comprises a housing, an electrode assembly, a cover plate, an insulating support structure, and a stop member. When thermal runaway occurs, the stop member is supported between the cover plate and the electrode assembly; 8%≤S1 / S3≤30%, 10%≤S2 / S4≤80%, and a gap is present between the insulating support structure and the inner wall of the housing to facilitate insertion of the insulating support structure into the housing; the gap between the insulating support structure and the inner wall of the housing serves as an airflow channel when the battery is in a normal operation state, ensuring that gas can flow through the gap area to a pressure relief mechanism; S1 / S3≤30%, so that the width of the insulating support structure can be prevented from being excessively small, thereby ensuring the insulation protection effect of the insulating support structure on the electrode assembly; 10%≤S2 / S4≤80%, so that S2 is prevented from being excessively small to avoid an excessively small exhaust channel, thereby effectively ensuring the exhaust effect during thermal runaway of the battery; in addition, S2 is prevented from being excessively large to avoid an undersized stop member, thereby ensuring the strength of the stop member.

Description

Blade batteries, battery modules and battery packs

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on February 4, 2024, with application number 202410154782.8 and invention name “Blade Battery, Battery Module and Battery Pack”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a blade battery, a battery module and a battery pack. Background Art

[0004] The blade battery housing has two openings on each side, housing the electrode assembly. A cover plate is installed on each opening, equipped with an explosion-proof valve. Between the cover plate and the electrode assembly, there are insulating support structures such as a lower plastic and end plates. When the battery experiences thermal runaway, a large amount of heat and gas is generated within a very short period of time. The explosion-proof valve has no time to release the gas, causing the air pressure inside the housing to increase. However, the gas is continuously venting at the explosion-proof valve, reducing the air pressure at the explosion-proof valve. The pressure is higher on the side without the explosion-proof valve. This pressure differential generates a force toward the explosion-proof valve, pushing the electrode assembly toward the bottom explosion-proof valve. The melting point of the plastic lower plastic and end plates is generally between 160°C and 170°C. When a battery cell experiences thermal runaway, the internal temperature of the cell can reach 400°C. Once the lower plastic and end plates melt, they lose their function of supporting the electrode assembly. Under the action of the pressure differential, the electrode assembly moves toward the cover plate with the explosion-proof valve, causing the exhaust space at the explosion-proof valve to decrease or even block the explosion-proof valve. As a result, the heat and gas generated inside the shell cannot be discharged in time, and a large amount of hot gas accumulates inside the shell, causing the internal air pressure to increase, leading to shell tearing, fire, and even battery explosion. In a battery module or battery pack, the heat inside the shell of the battery that triggers thermal runaway can be transferred to other batteries, causing adjacent or nearby batteries to trigger thermal runaway, resulting in serious safety issues.

[0005] Summary of the Invention

[0006] In view of this, the present application provides a blade battery, a battery module and a battery pack to solve the problem in the prior art that the electrode group of the blade battery is easy to move and block or obstruct the pressure relief mechanism on the cover when the battery thermal runaway occurs.

[0007] In a first aspect, the present application provides a blade battery, comprising:

[0008] a housing having at least one side open;

[0009] a pole group, disposed in the housing;

[0010] A cover plate is provided on at least one side opening of the shell; a pressure relief mechanism is provided on one side of the cover plate;

[0011] An insulating support structure is provided between the pole group and the cover plate; the insulating support structure includes a lower insulating member;

[0012] The stopper is made of a high-temperature resistant material; the stopper is arranged between the cover plate provided with the pressure relief mechanism and the pole group; when the blade battery is thermally runaway, after the insulating support structure melts, the two sides of the stopper facing the pole group and the cover plate are suitable for respectively abutting and supporting the pole group and the cover plate; the width of the insulating support structure is W, and the width of the pole group is D; before the insulating support structure melts, the cross-sectional area of ​​the gap area enclosed by the insulating support structure and the inner wall of the shell, the cover plate and the pole group, which is parallel to the bottom surface of the shell, is S1, and after the insulating support structure melts, the cross-sectional area of ​​the gap area enclosed by the stopper and the inner wall of the shell, the cover plate and the pole group, which is parallel to the bottom surface of the shell, is S2; before and after the insulating support structure melts, the cross-sectional areas of the area enclosed by the pole group, the inner wall of the shell and the cover plate, which are parallel to the bottom surface of the shell, are S3 and S4, respectively, 8%≤S1 / S3≤30%, 10%≤S2 / S4≤80%.

[0013] Beneficial effect: When the blade battery of this structure is in thermal runaway, the stopper can still be supported between the cover plate and the pole group, preventing the pole group from moving toward the cover plate and blocking or even blocking the pressure relief mechanism, thereby ensuring normal exhaust and pressure relief of the pressure relief mechanism; when the distance between the inner surface of the cover plate and the pole group and the shell size are constant, S3 is a constant value, S1 and S3 satisfy 8%≤S1 / S3, S1 is not too small, and there is a gap between the insulating support structure and the inner wall of the shell, which facilitates the insertion of the insulating support structure into the shell. At the same time, the gap between the insulating support structure and the inner wall of the shell serves as an airflow channel under normal working conditions of the battery, ensuring that the gas can flow to the pressure relief mechanism through the gap area; however, when the shell size and S3 are When S1 is too large, the distance between the insulating support structure and the inner wall of the shell is too large, and the width of the insulating support structure is too narrow, which cannot effectively provide internal insulation protection for the electrode group. The electrode group is easily damaged when entering the shell. Therefore, S1 / S3 is set to ≤ 30% to prevent the width of the insulating support structure from being too small, thereby ensuring its insulation protection effect on the electrode group; S2 and S4 meet 10% ≤ S2 / S4 ≤ 80% to prevent S2 from being too small and causing the exhaust channel to be too small, so as to effectively ensure the exhaust effect when the battery is thermally runaway, and at the same time avoid S2 being too large and causing the stopper to be too small, so as to ensure the strength of the stopper, thereby ensuring that it can still be stably maintained between the cover and the electrode group when squeezed by the electrode group.

[0014] In an optional embodiment, the width of the stopper extending along the width direction of the pole group is F, 50% D≤F≤95% W, and / or F≥5 mm.

[0015] In an optional embodiment, the length of the stopper extending along the height direction of the pole group is E; E≥50%D, and / or E≥5mm.

[0016] In an optional embodiment, the insulating support structure further includes an end plate, the lower insulating member is arranged on the inner side wall of the cover plate, and the end plate is arranged between the lower insulating member and the pole group; the width of the lower insulating member is B, the width of the end plate is C, 50% D≤F≤95% B, and / or 50% D≤F≤95%C.

[0017] Beneficial effects: preventing the stopper from being too small; at the same time preventing the stopper from protruding from the lower insulating member or the end plate, preventing interference when inserting into the shell, and ensuring assembly efficiency.

[0018] In an optional embodiment, the width between the inner walls of the two large surfaces of the shell is A, and 80%D≤W≤95%A.

[0019] Beneficial effect: ensuring that the lower insulating member or the end plate has sufficient width to provide good insulation protection for the pole group, while preventing the lower insulating member or the end plate from being too wide to be easily inserted into the shell.

[0020] In an optional embodiment, a first groove is provided on the insulating support structure, and the stopper is arranged in the first groove.

[0021] Beneficial effect: The stopper can be conveniently and quickly fixed on the insulating support structure. After the battery thermal runaway and the insulating support structure melts, the stopper is located between the cover plate and the pole group. When the pole group moves, the stopper is pushed so that the two sides of the stopper respectively abut against the cover plate and the pole group.

[0022] In an optional embodiment, an embedding portion and a fitting portion are respectively provided on the side of the cover plate facing the stopper. After the insulating support structure is melted, the fitting portion fits into the embedding portion to prevent the stopper from moving at will.

[0023] Beneficial effect: After the lower insulating part and the end plate are melted, the fitting part fits in the embedded part to prevent the stopper from moving at will, so that the stopper is stably supported between the cover plate and the pole group, ensuring the smoothness of the exhaust channel, and then ensuring that the pressure relief mechanism continuously and effectively exhausts and relieves pressure, thereby improving the safety performance of the battery.

[0024] In an optional embodiment, the stopper is in the shape of a rectangular block, and / or the stopper is arranged in the middle position in the width direction of the pole group.

[0025] Beneficial effect: The width of the stopper on both sides facing the cover plate and the pole group is equal. When the stopper and the pressure relief mechanism are offset, the contact surface of the stopper, the cover plate and the pole group is equal in size, so as to stably maintain and support between the cover plate and the pole group, preventing the contact surface between the stopper and the cover plate or the pole group from being too small to ensure stability, and preventing the contact surface on one side from being too small to crush the stopper.

[0026] Before and after the lower insulating member and the end plate are melted, the exhaust passages are located on both sides of the width direction of the stopper to ensure uniform and effective exhaust.

[0027] In a second aspect, the present application further provides a battery module comprising any of the blade batteries described above. Since the battery module comprises the blade battery, it has the same effects as the blade battery and will not be described in detail here.

[0028] In a third aspect, the present application further provides a battery pack including the above-mentioned battery module. Since the battery pack includes blade batteries, it has the same effects as the blade batteries and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0030] FIG1 is a front view of a blade battery according to an embodiment of the present application;

[0031] FIG2 is a cross-sectional view taken along the line AA of FIG1 ;

[0032] FIG3 is a front view of a shell in a blade battery according to an embodiment of the present application;

[0033] FIG4 is a front view of a lower insulating member in a blade battery according to an embodiment of the present application;

[0034] FIG5 is a front view of a middle end plate of a blade battery according to an embodiment of the present application;

[0035] FIG6 is a front view of an electrode group in a blade battery according to an embodiment of the present application;

[0036] FIG7 is a cross-sectional view of the lower insulating member, the end plate, the housing and the cover plate before the insulating support structure is melted;

[0037] FIG8 is a cross-sectional view of the lower insulating member mating with the housing and the cover before the insulating support structure melts;

[0038] FIG9 is a schematic diagram of a stop member;

[0039] FIG10 is a schematic diagram of the cross-sectional area S1 when the end plate is provided;

[0040] FIG11 is a schematic diagram of the cross-sectional area S1 when no end plate is provided;

[0041] FIG12 is a schematic diagram of the cross-sectional area S2;

[0042] FIG13 is a schematic diagram of the cross-sectional area S3;

[0043] FIG14 is a schematic diagram of the cross-sectional area S4.

[0044] Explanation of the reference numerals: 1. Shell; 101. Bottom surface; 2. Pole group; 3. Cover plate; 301. Second groove; 4. Pressure relief mechanism; 5. Lower insulating member; 501. First groove; 502. Boss; 6. Stopper; 601. Raised portion; 7. End plate. DETAILED DESCRIPTION

[0045] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0046] The following describes an embodiment of the present application in conjunction with Figures 1 to 14.

[0047] According to an embodiment of the present application, on the one hand, a blade battery is provided, comprising a shell 1, a pole group 2, a cover plate 3, an insulating support structure and a stopper 6. Among them, at least one side of the shell 1 is open; the pole group 2 is arranged in the shell 1; the cover plate 3 is arranged on at least one side of the opening of the shell 1; a pressure relief mechanism 4 is provided on one side of the cover plate 3; the insulating support structure is arranged between the pole group 2 and the cover plate 3; the insulating support structure includes a lower insulating member 5; the material of the stopper 6 is a high temperature resistant material; the stopper 6 is arranged between the cover plate 3 provided with the pressure relief mechanism 4 and the pole group 2; when the blade battery thermally runs away, after the insulating support structure melts, the two sides of the stopper 6 facing the pole group 2 and the cover plate 3 are suitable for respectively abutting against the supporting pole group 2 and the cover plate 3; the width of the insulating support structure is W, and the pole group 2 is The width is D; before the insulating support structure melts, the cross-sectional area of ​​the gap area enclosed by the insulating support structure and the inner wall of the shell 1, the cover plate 3 and the pole group 2, which is parallel to the bottom surface 101 of the shell 1, is S1; after the insulating support structure melts, the cross-sectional area of ​​the gap area enclosed by the stopper 6 and the inner wall of the shell 1, the cover plate 3 and the pole group 2, which is parallel to the bottom surface 101 of the shell 1, is S2; before and after the insulating support structure melts, the cross-sectional areas of the area enclosed by the pole group 2 and the inner wall of the shell 1 and the cover plate 3, which are parallel to the bottom surface 101 of the shell 1, are S3 and S4 respectively, 8%≤S1 / S3≤30%, 10%≤S2 / S4≤80%.

[0048] In the blade battery of this structure, when the blade battery thermally runs away, the temperature inside the shell 1 rises rapidly, the insulating support structure of the plastic material melts under high temperature, and the pole group 2 lacks the support function of the insulating support structure. Since the pressure relief mechanism 4 is always venting and relieving pressure, the pressure on the side of the pressure relief mechanism 4 is small, and the pressure on the side of the shell 1 where no pressure relief mechanism is set is large. Under the action of the pressure difference, the pole group 2 tends to move toward the side of the pressure relief mechanism 4; since a high-temperature resistant stopper 6 is provided between the cover plate 3 with the pressure relief mechanism 4 and the pole group 2, the stopper 6 can still be supported between the cover plate 3 and the pole group 2 under high temperature, preventing the pole group 2 from moving toward the cover plate 3 and blocking or even blocking the pressure relief mechanism Structure 4, to ensure that the pressure relief mechanism 4 is normally exhausted and pressure relieved; when the distance between the inner surface of the cover plate 3 and the electrode group 2 and the size of the shell 1 are constant, S3 is a constant value, S1 and S3 satisfy 8%≤S1 / S3, S1 is not too small, there is a gap between the insulating support structure and the inner wall of the shell 1, which is convenient for the insulating support structure to enter the shell, and at the same time, the gap between the insulating support structure and the inner wall of the shell 1 serves as an airflow channel under the normal working state of the battery, ensuring that the gas can flow to the pressure relief mechanism 4 through the gap area; however, when the size of the shell 1 and S3 are constant values, S1 is too large, then the distance between the insulating support structure and the inner wall of the shell 1 is too large, and the width of the insulating support structure is too narrow, The electrode group 2 cannot be effectively insulated and protected internally, and the electrode group 2 is easily damaged when entering the shell. Therefore, S1 / S3 is set to ≤ 30% to prevent the width of the insulating support structure from being too small, thereby ensuring its insulating protection effect on the electrode group 2. After the insulating support structure is melted, when the distance from the inner surface of the cover plate 3 to the electrode group 2 and the size of the shell 1 are constant, S4 is a constant value. The larger S2 is, the larger the exhaust channel is and the smaller the size of the stopper 6 is; the smaller S2 is, the smaller the exhaust channel is and the larger the size of the stopper 6 is. Therefore, S2 and S4 are set to meet 10% ≤ S2 / S4 ≤ 80% to prevent S2 from being too small and causing the exhaust channel to be too small, thereby effectively ensuring the exhaust effect during thermal runaway of the battery, and at the same time avoiding S2 from being too large and causing the size of the stopper 6 to be too small, thereby ensuring the strength of the stopper 6, thereby ensuring that it can still be stably maintained between the cover plate 3 and the electrode group 2 when squeezed by the electrode group 2.

[0049] The width of the stopper 6 extending along the width of the electrode assembly 2 is F, with 50% D ≤ F ≤ 95% W, and / or F ≥ 5 mm. This prevents the stopper 6 from being too narrow and embedding into the electrode assembly 2. Furthermore, if the stopper 6 is too large, its outer contour will not protrude beyond the insulating support structure, causing structural interference during insertion into the battery case, thereby ensuring automatic insertion and efficient battery assembly.

[0050] The length of the stopper 6 extending along the height direction of the pole group 2 is E, E≥50%D, and / or E≥5mm, to prevent the stopper 6 from being too short and being embedded in the pole group 2; at the same time, it can prevent the stopper 6 from being too large and causing structural interference when inserted into the shell.

[0051] Optionally, in one embodiment, as shown in Figures 7 and 10, the insulating support structure further includes an end plate 7. The lower insulating member 5 is disposed on the inner sidewall of the cover plate 3, and the end plate 7 is disposed between the lower insulating member 5 and the pole group 2. The lower insulating member 5 has a width B, and the end plate 7 has a width C, with 50% D ≤ F ≤ 95% B, and / or 50% D ≤ F ≤ 95% C. This prevents the stopper 6 from being too small and embedding into the pole group 2. When the end plate 7 is provided, the stopper 6 dimensions simultaneously meet F ≤ 95% B and / or F ≤ 95% C to prevent the stopper 6 from protruding beyond the lower insulating member 5 and / or the end plate 7, thereby preventing interference during insertion into the housing and ensuring assembly efficiency.

[0052] In this embodiment, as shown in Figures 7 and 10, the width of the lower insulating member 5 on the side facing the cover plate 3 is greater than the width on the side facing the pole group 2 to form a flange portion in the transition area. At this time, the width of the lower insulating member 5 at the maximum width position is B, and the side of the end plate 7 facing the cover plate 3 abuts on the flange portion. The width of the end plate 7 is the same as the width of the lower insulating member 5 at the flange portion. The side wall of the end plate 7 is flush with the side wall of the flange portion of the lower insulating member 5. The cross-sectional area of ​​the area between the side wall of the end plate 7 and the flange portion of the lower insulating member 5 and the inner wall of the shell 1 and the gap area surrounded by the cover plate 3 and the pole group 2 and parallel to the bottom surface 101 of the shell 1 is S1.

[0053] As shown in Figures 8 and 11, in other embodiments, the end plate 7 may not be provided. In this case, the width of the lower insulating member 5 toward the cover plate 3 and the pole group 2 is the same, and the area between the side wall of the lower insulating member 5 and the inner wall of the shell 1 forms a gap area with the cover plate 3 and the pole group 2. The cross-sectional area of ​​the gap area parallel to the bottom surface 101 of the shell 1 is S1.

[0054] As shown in FIG3 , the width between the inner walls of the two large surfaces of the shell 1 is A, 80% D ≤ W ≤ 95% A, that is, 80% D ≤ B ≤ 95% A, 80% D ≤ C ≤ 95% A, to ensure that the insulating support structures such as the lower insulating member 5 or the end plate 7 have sufficient width to provide good insulation protection for the pole group 2, while preventing the lower insulating member 5 or the end plate 7 from being too wide to be conveniently inserted into the shell.

[0055] When the inner width A of the shell 1 is 15 mm and the width D of the electrode group 2 is 13 mm, batteries with different stoppers 6 of E and F and different S1 / S3 and S2 / S4 are designed, and thermal runaway tests are carried out on the blade batteries. The test results are shown in Tables 1 and 2.

[0056] Table 1

[0057] Table 2

[0058] As shown in Example 1 in Table 1, when the conditions 50% D ≤ F ≤ 95% W, F ≥ 5 mm, 8% ≤ S1 / S3 ≤ 30%, 10% ≤ S2 / S4 ≤ 80% are all met, and when E < 5 mm, the length of the stopper 6 is too small. During the thermal runaway test, the stopper 6 is embedded in the pole group 2, and the thermal runaway test fails. From the comparison between Example 3 and Example 4 in Table 1, it can be seen that when the conditions E≥50%D, E≥5mm, 8%≤S1 / S3≤30%, and 10%≤S2 / S4≤80% are all met, and when F<50%D, since the width of the stopper 6 is too small, the stopper 6 is embedded in the pole group 2 during the thermal runaway test, and the thermal runaway test fails. From the comparison between Example 5 and Example 6 in Table 1, it can be seen that when the conditions 50%D≤F≤95%W, F≥5mm, E≥50%D, E≥5mm, and 10%≤S2 / S4≤80% are all met, and when S1 / S3<8%, due to the insulation support The gap between the structure and the inner wall of the shell 1 is too small, causing interference during assembly, and the pole group 2 cannot be inserted into the shell. When S1 / S3>30%, the insulating support structure is too narrow to effectively provide internal insulation protection for the pole group 2, and the pole group 2 is damaged when it is inserted into the shell. As shown in Examples 17 to 20 in Table 2, when the conditions 50%D≤F≤95%W, F≥5mm, E≥50%D, E≥5mm, and 8%≤S1 / S3≤30% are all met, but when S2 / S4>80%, the thermal runaway test fails because S2 is too large and the stop block is too small. When S2 / S4<10%, the thermal runaway test fails because the exhaust channel after thermal runaway is too small. As shown in Examples 2, 4, 7 to 16, when the conditions 50% D ≤ F ≤ 95% W, F ≥ 5 mm, E ≥ 50% D, E ≥ 5 mm, 8% ≤ S1 / S3 ≤ 30%, and 10% ≤ S2 / S4 ≤ 80% are all met, the thermal runaway tests are all passed.

[0059] When the inner width A of the shell 1 is 30 mm and the width D of the electrode group 2 is 27 mm, batteries with different stoppers 6 of E and F and different S1 / S3 and S2 / S4 are designed, and thermal runaway tests are carried out on the blade batteries. The test results are shown in Tables 3 and 4.

[0060] Table 3

[0061] Table 4

[0062] It can be seen from Example 21 in Table 3 that when the conditions 50% D ≤ F ≤ 95% W, F ≥ 5 mm, 8% ≤ S1 / S3 ≤ 30%, and 10% ≤ S2 / S4 ≤ 80% are all met, and when E < 50% D, since the length of the stopper 6 is too small, the stopper 6 is embedded in the pole group 2 during the thermal runaway test, and the thermal runaway test fails; It can be seen from Example 23 and Example 24 in Table 3 that when the conditions E ≥ 50% D, E ≥ 5 mm, 8% ≤ S1 / S3 ≤ 30%, and 10% ≤ S2 / S4 ≤ 80% are all met, and when F < 50% D, since the width of the stopper 6 is too small, the stopper 6 is embedded in the pole group 2 during the thermal runaway test, and the thermal runaway test fails; It can be seen from Example 25 and Example 26 in Table 3 that when the conditions 50% D ≤ F ≤ 95% W, F ≥ 5 mm, and E ≥ 5 0% D, E ≥ 5 mm, 10% ≤ S2 / S4 ≤ 80% are all satisfied. However, when S1 / S3 is less than 8%, the gap between the insulating support structure and the inner wall of the shell 1 is too small, resulting in interference during assembly and the pole group 2 cannot be inserted into the shell. When S1 / S3 is greater than 30%, the insulating support structure is too narrow to effectively provide internal insulation protection for the pole group 2, and the pole group 2 is damaged when inserted into the shell. As shown in Examples 37 to 40 in Table 4, when the conditions 50% D ≤ F ≤ 95% W, F ≥ 5 mm, E ≥ 50% D, E ≥ 5 mm, and 8% ≤ S1 / S3 ≤ 30% are all satisfied. However, when S2 / S4 is greater than 80%, the thermal runaway test fails because S2 is too large and the stop block is too small. When S2 / S4 is less than 10%, the thermal runaway test fails because the exhaust channel after thermal runaway is too small. As shown in Examples 22, 24, 27 to 36, when the conditions 50% D ≤ F ≤ 95% W, F ≥ 5 mm, E ≥ 50% D, E ≥ 5 mm, 8% ≤ S1 / S3 ≤ 30%, and 10% ≤ S2 / S4 ≤ 80% are all met, the thermal runaway tests are passed.

[0063] As shown in Figures 7, 8, 10 and 11, a first groove 501 is provided on the insulating support structure, and the stopper 6 is provided in the first groove 501 to conveniently and quickly fix the stopper 6 on the insulating support structure. After the battery thermal runaway and the insulating support structure melts, the stopper 6 is located between the cover plate 3 and the pole group 2. When the pole group 2 moves, it pushes the stopper 6 so that the two sides of the stopper 6 respectively abut against the cover plate 3 and the pole group 2.

[0064] In other embodiments, the stopper 6 can also be fixed on the pole group 2, the cover plate 3 or the side plate at the bottom of the shell 1. As long as the stopper 6 is arranged between the cover plate 3 and the pole group 2, it can support the pole group 2 after the insulating support structure melts and prevent the pole group 2 from moving toward the side of the pressure relief mechanism 4 and blocking or blocking the pressure relief mechanism 4.

[0065] As shown in Figures 7 and 8, in one embodiment, the first groove 501 is provided on the lower insulating member 5, and the stop member 6 is integrally injection molded with the lower insulating member 5. The stop member 6 is easy to manufacture, and no additional process is required in the production of the blade battery, and the stop member 6 can be stably maintained on the lower insulating member 5.

[0066] In this embodiment, the first groove 501 is located inside the lower insulating member 5 , and the stopper 6 is wrapped inside the lower insulating member 5 .

[0067] In other embodiments, the stopper 6 may also be interference-fitted in the first groove 501 or snap-fitted in the first groove 501 , and the stopper 6 may also be adhesively fixed in the first groove 501 .

[0068] As shown in Figures 7, 8, 10 to 12, an embedding portion and a fitting portion are respectively provided on the side facing each other of the cover plate 3 and the stopper 6. After the lower insulating member 5 and the end plate 7 are melted, the fitting portion fits into the embedding portion to prevent the stopper 6 from moving at will, so that the stopper 6 is stably supported between the cover plate 3 and the electrode group 2, ensuring the smoothness of the exhaust channel, and further ensuring that the pressure relief mechanism 4 continuously and effectively exhausts and relieves pressure, thereby improving the safety performance of the battery.

[0069] Optionally, the embedded portion is a second groove 301 provided on the cover plate 3, and the mating portion is a raised portion 601 provided on the stopper 6. A boss 502 is correspondingly provided on the lower insulator 5, protruding toward the second groove 301. The raised portion 601 is accommodated within the boss 502. Before the lower insulator 5 and the end plate 7 melt, the raised portion 601 extends toward the second groove 301. This allows the raised portion 601 to quickly embed within the second groove 301 when the stopper 6 is squeezed by the pole group 2 after the lower insulator 5 and the end plate 7 melt, thereby limiting the position of the stopper 6 and preventing it from arbitrarily moving or deflecting along the height direction of the cover plate 3, thereby ensuring that the stopper 6 stably supports the pole group 2 and the cover plate 3.

[0070] Because the stopper 6 may move slightly along the width of the cover plate 3 when squeezed by the pole group 2, in this embodiment, the second groove 301 is a waist-shaped groove, extending along the width of the cover plate 3, and the protrusion 601 is cylindrical. The length of the second groove 301 is greater than the diameter of the protrusion 601. Before the lower insulating member 5 and the end plate 7 are melted, the protrusion 601 is located in the middle of the second groove 301. Because the length of the second groove 301 is greater than the diameter of the protrusion 601, even if the stopper 6 moves slightly along the width of the cover plate 3, the protrusion 601 can be ensured to be embedded in the second groove 301.

[0071] In other embodiments, the second groove 301 may also be provided on the stopper 6 , and the protrusion 601 may be provided on the cover plate 3 accordingly.

[0072] In one embodiment, the stopper 6 is in the shape of a rectangular block, and its width on both sides facing the cover plate 3 and the pole group 2 is equal. When the stopper 6 and the pressure relief mechanism 4 are offset, the contact surface of the stopper 6 and the cover plate 3 and the pole group 2 is equal in size, so as to stably maintain and support between the cover plate 3 and the pole group 2, prevent the contact surface of the stopper 6 and the cover plate 3 or the pole group 2 from being too small to ensure stability, and prevent the contact surface on one side from being too small to crush the stopper 6.

[0073] In one embodiment, the stopper 6 is a solid structure. In other embodiments, the stopper 6 can also be a hollow structure while ensuring the strength of the stopper 6. As shown in Figures 7 and 8, the cross-section of the stopper 6 parallel to the bottom surface 101 of the housing 1 can also be a trapezoidal, parallelogram, etc., as long as it has two flat surfaces that can abut against the cover plate 3 and the electrode assembly 2.

[0074] As shown in Figures 10 to 12, the stopper 6 is arranged in the middle position in the width direction of the pole group 2. Before and after the lower insulating member 5 and the end plate 7 are melted, the exhaust channels are located on both sides of the stopper 6 in the width direction to ensure uniform and effective exhaust.

[0075] Optionally, the lower insulating member 5 includes lower plastic.

[0076] Optionally, in one embodiment, the pressure relief mechanism 4 is an explosion-proof valve, and a pole is further provided on the cover plate 3 .

[0077] The material of the stopper 6 is aluminum alloy, ceramic, stainless steel or copper, etc. The material of the stopper 6 is also resistant to corrosion by the electrolyte so that it can be stably maintained in the housing 1 for a long time.

[0078] According to an embodiment of the present application, on the other hand, a battery module is provided, including the above-mentioned blade battery.

[0079] In a battery module of this structure, when the blade battery on it experiences thermal runaway, the stopper 6 can still be supported between the cover plate 3 and the electrode group 2, preventing the electrode group 2 from moving toward the cover plate 3 and blocking or even blocking the pressure relief mechanism 4, thereby ensuring normal exhaust and pressure relief of the pressure relief mechanism 4; the length and width of the stopper 6 meet 50% D≤F≤95%W, E≥5mm, preventing the stopper 6 from being too small in width or length and being embedded in the electrode group 2, while preventing the stopper 6 from being too large in size, thereby ensuring automatic shell insertion and battery assembly efficiency; at the same time, the cross-sectional area meets 8%≤S1 / S3≤30%, 1 0%≤S2 / S4≤80%, which facilitates the insertion of the insulating support structure into the shell and ensures that the gas can flow to the pressure relief mechanism 4 through the gap area; prevents the width of the insulating support structure from being too small to ensure its insulation protection effect on the electrode group 2; prevents the exhaust channel from being too small to effectively ensure the exhaust effect during thermal runaway of the battery, and at the same time avoids the size of the stopper 6 from being too small to ensure the strength of the stopper 6 and ensure that it can still be stably maintained between the cover plate 3 and the electrode group 2 when squeezed by the electrode group 2, so as to ensure timely and effective exhaust of the explosion-proof valve during thermal runaway and ensure the safety of the battery module.

[0080] According to an embodiment of the present application, on another aspect, a battery pack is provided, comprising the above-mentioned battery module.

[0081] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A blade battery, characterized in that: include: a housing having at least one side open; a pole group, disposed in the housing; a cover plate, disposed on at least one side opening of the housing; A pressure relief mechanism is provided on the cover plate on one side; An insulating support structure is provided between the pole group and the cover plate; the insulating support structure includes a lower insulating member; The stopper is made of a high-temperature resistant material; the stopper is arranged between the cover plate provided with the pressure relief mechanism and the pole group; when the blade battery is thermally runaway, after the insulating support structure melts, the two sides of the stopper facing the pole group and the cover plate are suitable for respectively abutting and supporting the pole group and the cover plate; the width of the insulating support structure is W, and the width of the pole group is D; before the insulating support structure melts, the cross-sectional area of the gap area enclosed by the insulating support structure and the inner wall of the shell, the cover plate and the pole group, which is parallel to the bottom surface of the shell, is S1, and after the insulating support structure melts, the cross-sectional area of the gap area enclosed by the stopper and the inner wall of the shell, the cover plate and the pole group, which is parallel to the bottom surface of the shell, is S2; before and after the insulating support structure melts, the cross-sectional areas of the area enclosed by the pole group, the inner wall of the shell and the cover plate, which are parallel to the bottom surface of the shell, are S3 and S4, respectively, 8%≤S1 / S3≤30%, 10%≤S2 / S4≤80%.

2. The blade battery according to claim 1, characterized in that: The width of the stopper extending along the width direction of the pole group is F, 50% D≤F≤95% W, and / or F≥5 mm.

3. The blade battery according to claim 1 or 2, characterized in that: The length of the stopper extending along the height direction of the pole group is E; E≥50%D, and / or E≥5mm.

4. The blade battery according to claim 1 or 2, characterized in that: The insulating support structure also includes an end plate, the lower insulating member is arranged on the inner side wall of the cover plate, and the end plate is arranged between the lower insulating member and the pole group; the width of the lower insulating member is B, the width of the end plate is C, 50% D≤F≤95% B, and / or 50% D≤F≤95%C.

5. The blade battery according to claim 1 or 2, characterized in that: The width between the inner walls of the two large surfaces of the shell is A, and 80%D≤W≤95%A.

6. The blade battery according to claim 1 or 2, characterized in that: The insulating support structure is provided with a first groove, and the stopper is arranged in the first groove.

7. The blade battery according to claim 1 or 2, characterized in that: An embedding portion and a matching portion are respectively provided on one side of the cover plate facing the stopper. After the insulating support structure is melted, the matching portion is matched in the embedding portion to prevent the stopper from moving at will.

8. The blade battery according to claim 1 or 2, characterized in that: The stopper is in the shape of a rectangular block, and / or the stopper is arranged in the middle position in the width direction of the pole group.

9. A battery module, characterized in that: The blade battery comprises the blade battery according to any one of claims 1 to 8.

10. A battery pack, characterized in that: Comprising the battery module according to claim 9.

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