Secondary battery, battery pack, and electric device

Abstract

This application discloses a secondary battery, a battery pack, and an electrical device. The secondary battery has intersecting first and second directions and includes a housing, an electrode assembly, and a top cover assembly. The housing has a receiving cavity, and the electrode assembly is disposed in the receiving cavity. The top cover assembly includes a top cover plate, a lower insulating member, and electrode terminals. The top cover plate is connected to the housing and has a first liquid injection hole. The lower insulating member is connected to the side of the top cover plate facing the electrode assembly, and the electrode terminals pass through the top cover plate and the lower insulating member. The lower insulating member includes a body and a flow-dispersing part. The body has a second liquid injection hole communicating with the first liquid injection hole. The flow-dispersing part is connected to the side of the body away from the top cover plate and is spaced apart from the electrode terminals. The side of the flow-dispersing part facing the electrode terminals has a liquid outlet communicating with the second liquid injection hole. Along the second direction, the minimum distance between the liquid outlet and the electrode terminals is L1, and the size of the top cover plate is L2, satisfying 0.004≤L1 / L2≤0.5.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a secondary battery, a battery pack, and an electrical device. Background Technology

[0002] During the production of secondary batteries, electrolyte is injected into the casing. The hydraulic pressure during electrolyte injection is significant, resulting in considerable impact on the internal electrode components. This can easily cause the separator of the electrode components to fold, leading to a short circuit within the secondary battery. Summary of the Invention

[0003] Purpose of the invention: This application provides a secondary battery to solve the problem that existing batteries are prone to membrane folding and internal short circuits when electrolyte is injected; another purpose of this application is to provide a battery pack; yet another purpose of this application is to provide an electrical device.

[0004] Technical solution: A secondary battery according to an embodiment of this application has intersecting first and second directions, including:

[0005] The shell has a receiving cavity;

[0006] The electrode assembly is disposed within the receiving cavity;

[0007] A top cover assembly includes a top cover sheet, a lower insulating member, and electrode terminals. The top cover sheet is connected to the housing and covers the receiving cavity. The top cover sheet has a first liquid injection hole. Along the first direction, the lower insulating member is connected to the side of the top cover sheet facing the electrode assembly. The electrode terminals pass through the top cover sheet and the lower insulating member and are electrically connected to the electrode assembly.

[0008] The lower insulating element includes:

[0009] The body is connected to the top cover plate, and the body has a second injection hole that communicates with the first injection hole;

[0010] A flow-dispersing section is connected to the side of the body away from the top cover plate; along the first direction, at least a portion of the flow-dispersing section is spaced between the first injection hole and the electrode assembly; the flow-dispersing section and the electrode terminal are spaced apart along the second direction, and the flow-dispersing section has an outlet on the side facing the electrode terminal, and the outlet communicates with the second injection hole;

[0011] Along the second direction, the minimum distance between the liquid outlet and the electrode terminal is L1 mm, and the size of the top cover plate is L2 mm, satisfying: 0.004≤L1 / L2≤0.5.

[0012] In some embodiments, along the second direction, the minimum distance between the liquid outlet and the electrode terminal and the size of the top cover plate satisfy: 0.04≤L1 / L2≤0.39.

[0013] In some embodiments, along the second direction,

[0014] The minimum distance between the liquid outlet and the electrode terminal satisfies: 2≤L1≤50; and / or,

[0015] The dimensions of the top cover plate satisfy: 100≤L2≤500.

[0016] In some embodiments, along the second direction,

[0017] The minimum distance between the liquid outlet and the electrode terminal satisfies: 5 ≤ L1 ≤ 39; and / or,

[0018] The dimensions of the top cover plate satisfy: 100≤L2≤250.

[0019] In some embodiments,

[0020] The lower insulating component includes an explosion-proof valve boss, which is connected to the side of the body facing the electrode assembly. Along the second direction, the explosion-proof valve boss is disposed on the side of the turbulence portion away from the electrode terminal, and the explosion-proof valve boss is spaced apart from the turbulence portion.

[0021] The turbulence section has multiple liquid outlets, and at least one of the liquid outlets is positioned facing the explosion-proof valve boss.

[0022] In some embodiments, along the second direction, the minimum distance between the explosion-proof valve boss and the liquid outlet facing the explosion-proof valve boss is A mm, satisfying: 0.004 ≤ A / L² ≤ 0.5; or,

[0023] Along the second direction, the minimum distance between the explosion-proof valve boss and the liquid outlet facing the explosion-proof valve boss, and the size of the top cover plate satisfy: 0.04≤A / L2≤0.39.

[0024] In some embodiments, along the second direction,

[0025] The minimum distance between the explosion-proof valve boss and the outlet facing it satisfies: 2≤A≤50; and / or,

[0026] The dimensions of the top cover plate satisfy: 100≤L2≤500.

[0027] In some embodiments, along the second direction,

[0028] The minimum distance between the explosion-proof valve boss and the outlet facing it satisfies: 5 ≤ A ≤ 39; and / or,

[0029] The dimensions of the top cover plate satisfy: 100≤L2≤250.

[0030] In some embodiments, the turbulence section has a cavity, which is connected to the second injection hole and the outlet, respectively.

[0031] In some embodiments, the flow-disrupting portion includes:

[0032] A side plate is disposed on the side of the body away from the top cover plate and connected to the body. The side plate is disposed on the outer periphery of the second injection hole. The side plate has the liquid outlet, which penetrates the side plate along the first direction.

[0033] A baffle is connected to the side of the side plate away from the body. Along the first direction, the baffle is spaced between the first injection hole and the electrode assembly; the baffle and the side plate form the cavity.

[0034] In some embodiments, along the first direction, the area of ​​the orthographic projection of the side of the baffle facing the first injection hole onto the body is S1 mm. 2 The opening area of ​​the first injection hole is S2 mm. 2 The condition is satisfied that: 1.06≤S1 / S2≤10.

[0035] In some embodiments,

[0036] The area of ​​the orthographic projection of the side of the baffle facing the first injection hole onto the main body satisfies: 8.5 ≤ S1 ≤ 60; and / or,

[0037] The opening area of ​​the first injection hole satisfies: 6≤S2≤8.

[0038] In some embodiments, the secondary battery has a third direction intersecting the second direction, the electrode assembly includes tabs that are electrically connected to the electrode terminals, and the side plate and the tabs are spaced apart along the third direction.

[0039] In some embodiments, the side plate includes a plurality of sub-plates, the sub-plates being arranged in an arc shape around the outer periphery of the second injection hole, the plurality of sub-plates being spaced apart, the sub-plates being connected to the body, the end of the sub-plate away from the body being connected to the baffle, and two adjacent sub-plates, the baffle, and the body forming a liquid outlet.

[0040] In some embodiments, the side of the baffle facing the second injection hole is one of a plane, an arcuate surface protruding towards the second injection hole, and a conical surface protruding towards the second injection hole.

[0041] Accordingly, the battery pack described in this application includes a secondary battery as described in any of the foregoing embodiments.

[0042] Accordingly, an electrical device described in this application includes a secondary battery as described in any of the foregoing embodiments, or a battery pack as described in the foregoing embodiments.

[0043] Beneficial effects: Compared with the prior art, a secondary battery according to an embodiment of this application has intersecting first and second directions, including a shell, an electrode assembly and a top cover assembly. The shell has a receiving cavity, the electrode assembly is disposed in the receiving cavity, and the top cover assembly includes a top cover sheet, a lower insulating member and electrode terminals. The top cover sheet is connected to the shell and seals the receiving cavity, and the top cover sheet has a first liquid injection hole. Along the first direction, the lower insulating member is connected to the side of the top cover sheet facing the electrode assembly. The electrode terminals pass through the top cover sheet and the lower insulating member, and are electrically connected to the electrode assembly. The lower insulating component includes a body and a flow-dispersing part. The body is connected to the top cover plate and has a second liquid injection hole communicating with the first liquid injection hole. The flow-dispersing part is connected to the side of the body away from the top cover plate. Along the first direction, at least a portion of the flow-dispersing part is spaced between the first liquid injection hole and the electrode assembly. The flow-dispersing part and the electrode terminal are spaced apart along the second direction. The side of the flow-dispersing part facing the electrode terminal has a liquid outlet communicating with the second liquid injection hole. Along the second direction, the minimum distance between the liquid outlet and the electrode terminal is L1 mm, and the size of the top cover plate is L2 mm, satisfying: 0.004≤L1 / L2≤0.5. This application achieves a change in the electrolyte injection direction by setting a turbulence-disrupting part and configuring an outlet facing the electrode terminals. This reduces the direct impact of the electrolyte on the electrode assembly, thereby reducing the risk of the electrolyte impacting the diaphragm, causing the diaphragm to fold and leading to an internal short circuit in the secondary battery. In addition, by setting the ratio between the distance between the outlet and the electrode terminals and the size of the top cover plate, the outlet is ensured to be as unobstructed as possible, which reduces the obstruction effect of the electrode terminals on the electrolyte, thus achieving better electrolyte injection efficiency.

[0044] Compared with the prior art, a battery pack according to an embodiment of this application includes a secondary battery as described in any of the foregoing embodiments. It is understood that the battery pack of this application includes all the technical features and effects of the aforementioned secondary batteries, which will not be repeated here.

[0045] Compared with the prior art, an electrical device according to an embodiment of this application includes a secondary battery as described in any of the foregoing embodiments, or a battery pack as described in the foregoing embodiments. It is understood that the electrical device according to an embodiment of this application includes all the technical features and effects of the aforementioned secondary battery or battery pack, which will not be repeated here. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the overall structure of a secondary battery according to an embodiment of this application;

[0048] Figure 2 This is an exploded view of a secondary battery according to an embodiment of this application;

[0049] Figure 3 This is a cross-sectional view of a secondary battery according to an embodiment of this application, perpendicular to the second direction.

[0050] Figure 4 yes Figure 3 Enlarged view of section A;

[0051] Figure 5 This is a schematic diagram of the structure of a top cover assembly of a secondary battery according to an embodiment of this application;

[0052] Figure 6 This is a cross-sectional view of a secondary battery according to an embodiment of this application along a first direction and a second direction;

[0053] Figure 7 yes Figure 6 Enlarged view of section B;

[0054] Figure 8 This is a bottom view of a secondary battery according to an embodiment of this application, perpendicular to a first direction.

[0055] Reference numerals: 1. Housing; 11. Receiving cavity; 2. Electrode assembly; 21. Electrode tab; 22. Core; 3. Top cover assembly; 31. Top cover plate; 311. First injection hole; 32. Lower insulating component; 321. Body; 3211. Second injection hole; 322. Turbulence section; 3221. Liquid outlet; 3222. Cavity; 3223. Side plate; 3224. Baffle; 323. Explosion-proof valve boss; 3231. Through hole; 324. Groove; 33. Electrode terminal; 34. Explosion-proof valve; Z, First direction; X, Second direction; Y, Third direction. Detailed Implementation

[0056] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0057] In the description of this application, it should be understood that the terms "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, and "at least one" can mean one, two, or more, unless otherwise explicitly specified. In the description of this application, "perpendicular" means completely perpendicular to 90° or almost completely perpendicular, for example, the range of included angles from 80° to 100° is considered perpendicular. Similarly, "parallel" means completely parallel or almost completely parallel, for example, the range of completely parallel angles from 10° is considered parallel.

[0058] It should also be noted that in the accompanying drawings of this application, an arrow labeled Z indicates the first direction Z, an arrow labeled X indicates the second direction X, and an arrow labeled Y indicates the third direction Y. The introduction of the first direction Z, the second direction X, and the third direction Y is to facilitate the description of the structural positional relationships of the secondary battery, thereby aiding in understanding its structure. In the embodiments of this application, the first direction Z is the height direction of the secondary battery, the second direction X is the length direction of the secondary battery, and the third direction Y is the width direction of the secondary battery; furthermore, the first direction Z, the second direction X, and the third direction Z intersect each other, and more specifically, the first direction Z, the second direction X, and the third direction Y are perpendicular to each other.

[0059] In the field of power battery technology, during the production of secondary batteries, electrolyte is typically injected into the battery through an injection port located on the top cover assembly. Higher electrolyte injection efficiency leads to higher battery production efficiency. However, in current battery production processes, to improve injection efficiency, the electrolyte injection pressure is usually quite high. This can easily impact the separator of the electrode assembly, causing it to fold and potentially leading to a short circuit within the secondary battery. Conversely, reducing the injection pressure results in lower electrolyte injection efficiency.

[0060] In view of this, embodiments of this application provide a secondary battery, a battery pack, and an electrical device, aiming to solve the above-mentioned problems.

[0061] Please refer to the following: Figures 1-8 This application provides a secondary battery with intersecting first direction Z and second direction X, including a housing 1, an electrode assembly 2, and a top cover assembly 3. The housing 1 has a receiving cavity 11, and the electrode assembly 2 is disposed in the receiving cavity 11. The top cover assembly 3 includes a top cover plate 31, a lower insulating member 32, and electrode terminals 33. The top cover plate 31 is connected to the housing 1 and covers the receiving cavity 11. The top cover plate 31 has a first liquid injection hole 311. Along the first direction Z, the lower insulating member 32 is connected to the side of the top cover plate 31 facing the electrode assembly 2. The electrode terminals 33 pass through the top cover plate 31 and the lower insulating member 32, and are electrically connected to the electrode assembly 2. The lower insulating member 32 includes the... The body 321 and the flow-dispersing part 322 are connected to the top cover plate 31. The body 321 has a second injection hole 3211 that communicates with the first injection hole 311. The flow-dispersing part 322 is connected to the side of the body 321 away from the top cover plate 31. Along the first direction Z, at least a portion of the flow-dispersing part 322 is spaced between the first injection hole 311 and the electrode assembly 2. The flow-dispersing part 322 and the electrode terminal 33 are spaced apart along the second direction X. The side of the flow-dispersing part 322 facing the electrode terminal 33 has an outlet 3221 that communicates with the second injection hole 3211. Along the second direction X, the minimum distance between the outlet 3221 and the electrode terminal 33 is L1 mm, and the size of the top cover plate 31 is L2 mm, satisfying: 0.004≤L1 / L2≤0.5.

[0062] In this embodiment, by setting a flow-dissipating part 322 and configuring an outlet 3221, with the outlet 3221 facing the electrode terminal 33, the direction of electrolyte injection is changed, reducing the direct impact of the electrolyte on the electrode assembly 2, thereby reducing the risk of electrolyte impacting the diaphragm and causing the diaphragm to fold and thus causing a short circuit inside the secondary battery; in addition, by setting the ratio between the distance between the outlet 3221 and the electrode terminal 33 and the size of the top cover plate 31, it is ensured that the outlet 3221 is not blocked, thereby achieving a better electrolyte discharge efficiency.

[0063] Specifically, in this embodiment, the flow-disrupting part 322 is disposed on the side of the body 321 away from the top cover plate 31, and is spaced between the first injection hole 311 and the electrode assembly 2. At this time, the flow-disrupting part 322 can make the electrolyte injected from the first injection hole 311 preferentially impact the flow-disrupting part 322. The flow-disrupting part 322 directly interferes with the flow direction of the electrolyte, changing the electrolyte from flowing towards the electrode assembly 2 to flowing towards the electrode terminal 33 through the outlet 3221. This can reduce the possibility of the separator folding due to the direct impact of the electrolyte on the electrode assembly 2, thereby effectively reducing the possibility of internal short circuit in the secondary battery and improving the safety of the secondary battery.

[0064] It should be noted that in this embodiment, the outlet 3221 is positioned facing the electrode terminal 33, meaning the outlet 3221 and the electrode terminal 33 are opposite each other. In this case, the minimum distance between the outlet 3221 and the electrode terminal 33 is the distance between the nearest point of the electrode terminal 33 to the outlet 3221 and the plane containing the outlet 3221. Since the electrolyte flowing from the outlet 3221 flows towards the electrode terminal 33, contacts it, and is blocked by it, controlling the minimum distance between the electrode terminal 33 and the outlet 3221 within a reasonable range can reduce the blocking effect of the electrode terminal 33 on the electrolyte, thus ensuring a high electrolyte injection efficiency for the battery cell. Further details are needed. Figure 7 and Figure 8 When the distance between electrode terminal 33 and outlet 3221 is relatively large, it will not negatively affect the electrolyte injection efficiency. However, if the distance between electrode terminal 33 and outlet 3221 is relatively small, the electrolyte rushing out of outlet 3221 will directly impact electrode terminal 33, causing some obstruction to the electrolyte. In this case, electrode terminal 33 may also affect the outflow rate of outlet 3221 and may also adversely affect the voltage of electrode terminal 33. Therefore, in this embodiment, the minimum distance between outlet 3221 and electrode terminal 33 along the second direction X is set to L1 mm, and the size of top cover plate 31 is L2 mm, satisfying: 0.004≤L1 / L2≤0.5. Within this range, there is a relatively reasonable distance between outlet 3221 and electrode terminal 33, and electrode terminal 33 will not obstruct the electrolyte, ensuring that the secondary battery has good electrolyte injection efficiency.

[0065] It should also be noted that, in the embodiments of this application, the value range of L1 / L2 can be 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.078, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2 The range of any one or any two values ​​from 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, and 0.5. When the minimum distance L1 between the outlet 3221 and the electrode terminal 33 and the size L2 of the top cover plate 31 satisfy the range of 0.004 ≤ L1 / L2 ≤ 0.5, the minimum distance between the outlet 3221 and the electrode terminal 33 and the size of the top cover plate 31 are within a reasonable range. This reduces the possibility of the diaphragm of the electrode assembly 2 being folded due to electrolyte impact and ensures a faster electrolyte injection efficiency. Furthermore, the larger the value of L1 / L2, the smaller the impact of the electrode terminal 33 on the electrolyte injection efficiency. If L1 / L2 < 0.004, the distance between the outlet 3221 and the electrode terminal 33 is relatively close relative to the overall size of the top cover assembly 3. The electrode terminal 33 may obstruct the electrolyte, potentially affecting the electrolyte injection efficiency. Additionally, a small distance between the outlet 3221 and the electrode terminal 33 may lead to poor voltage at the electrode terminal 33. If L1 / L2 > 0.5, the distance between the outlet 3221 and the electrode terminal 33 is relatively large compared to the overall size of the top cover assembly 3. This could potentially prevent production, as the injection hole and electrode terminal 33 cannot be properly positioned within the length of the top cover plate 31, leading to an unfortunate situation where the top cover assembly 3 cannot be manufactured normally. Therefore, it is essential to control the distance between the electrode terminal 33 and the outlet 3221 within a reasonable range. This ensures good electrolyte injection efficiency and prevents the separator of the electrode assembly 2 from folding, thereby improving the yield and safety of the secondary battery.

[0066] In some embodiments, along the second direction X, the minimum distance between the liquid outlet 3221 and the electrode terminal 33, and the size of the top cover plate 31, further satisfy: 0.04≤L1 / L2≤0.39.

[0067] In some embodiments, L1 and L2 can be obtained by selecting some common dimensional measurement methods. For example, they can be measured directly using measuring tools such as vernier calipers or micrometers.

[0068] In some embodiments, further refer to Figure 7 and Figure 8 Along the second direction X, the minimum distance between the liquid outlet 3221 and the electrode terminal 33 satisfies: 2≤L1≤50. For example, the value range of L1 can be any one value or a range between any two values ​​of 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50. If L1 is too large, for the prismatic battery of this embodiment, the two electrode terminals 33 cannot be properly arranged on the top cover plate 31, which will prevent the top cover assembly 3 from being manufactured normally. If L1 is too small, the electrode terminals 33 will block the electrolyte flowing out of the outlet 3221, resulting in a decrease in the electrolyte flow rate and affecting the electrolyte injection efficiency of the secondary battery. In addition, it is also easy to interfere with the voltage of the electrode terminals 33, resulting in poor voltage of the electrode terminals 33. It should also be noted that if L1 is too small, the electrolyte may still have a relatively fast speed after being blocked by the electrode terminals 33 and changing direction, and impact the electrode assembly 2. This may also cause the separator of the electrode assembly 2 to fold, thereby causing a short circuit inside the secondary battery. Furthermore, the minimum distance between the outlet 3221 and the electrode terminals 33 satisfies: 3≤L1≤40.

[0069] In some embodiments, along the second direction X, the dimensions of the top cover plate 31 satisfy: 100 ≤ L2 ≤ 500. For example, the value of L2 can be any one or any two values ​​from 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, and 500. If the dimension L2 of the top cover plate 31 is too large, it may lead to difficulties in manufacturing or deformation of the corresponding lower insulating component 32. If the size of the top cover plate 31 is too small, it will be detrimental to the reasonable layout of the current-disrupting part 322 and the electrode terminal 33, and the battery capacity will also be smaller. Furthermore, in some embodiments, the size of the top cover plate 31 satisfies: 100≤L2≤250.

[0070] Please refer to section 4- Figure 8 In some embodiments, the lower insulating member 32 includes an explosion-proof valve boss 323, which is connected to the side of the body 321 facing the electrode assembly 2. Along the second direction X, the explosion-proof valve boss 323 is disposed on the side of the turbulence-disrupting part 322 away from the electrode terminal 33, and the explosion-proof valve boss 323 is spaced apart from the turbulence-disrupting part 322. The turbulence-disrupting part 322 has a plurality of liquid outlets 3221, and at least one liquid outlet 3221 is disposed facing the explosion-proof valve boss 323.

[0071] In this embodiment, by providing multiple liquid outlets 3221, the liquid injection efficiency can be further improved. Preferably, two liquid outlets 3221 are provided, one of which is positioned towards the electrode terminal 33, and the other is positioned towards the explosion-proof valve boss 323. This avoids the electrolyte flowing out of the liquid outlets 3221 from directly impacting the tab 21 and affecting the welding effect of the tab 21. At the same time, it also prevents the tab 21 from short-circuiting by colliding with the top cover plate 31 through the liquid outlets 3221.

[0072] It should be noted that, in this embodiment, the top cover assembly 3 includes an explosion-proof valve 34, which is embedded in the top cover plate 31 and is used to release pressure when the internal pressure is too high due to thermal runaway of a single battery cell. An explosion-proof valve boss 323 is disposed opposite to the explosion-proof valve 34 along the first direction Z, and a groove 324 is provided on the side of the lower insulating member 32 facing the explosion-proof valve 34. The groove 324 penetrates the body 321 along the first direction Z and is recessed into the explosion-proof valve boss 323, thus providing space for gas flow around the explosion-proof valve 34, facilitating direct action of thermal runaway gas on the explosion-proof valve 34. The explosion-proof valve boss 323 also has a through hole 3231, which penetrates the explosion-proof valve boss 323 along the first direction Z and communicates with the groove 324, facilitating the flow of thermal runaway gas. Simultaneously, the through hole 3231 also provides a buffer path for electrolyte flow, making electrolyte injection easier.

[0073] Please refer to section 7- Figure 8 In some embodiments, along the second direction X, the minimum distance between the explosion-proof valve boss 323 and the liquid outlet 3221 facing the explosion-proof valve boss 323 is A mm, satisfying: 0.004≤A / L2≤0.5.

[0074] In this embodiment, by setting the minimum distance between the explosion-proof valve boss 323 and the outlet 3221 facing the explosion-proof valve boss 323 to satisfy the size of the top cover plate 31 within the range of 0.004≤A / L2≤0.5, the outlet 3221, which is positioned opposite to the explosion-proof valve boss 323, can smoothly discharge electrolyte, thereby further improving the electrolyte injection efficiency. At this time, both the outlet 3221 opposite to the electrode terminal 33 and the outlet 3221 opposite to the explosion-proof valve boss 323 can quickly discharge electrolyte, so that the turbulence-dispersing part 322 can have a high discharge efficiency while blocking and turbulenting the electrolyte to prevent the diaphragm from bending.

[0075] Understandably, the range of A / L2 can be 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.078, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, The range of any one or any two values ​​from 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, and 0.5. When the minimum distance between the outlet 3221 and the explosion-proof valve boss 323 and the size of the top cover plate 31 are within the range of 0.004 ≤ A / L2 ≤ 0.5, the minimum distance between the outlet 3221 and the explosion-proof valve boss 323 and the size of the top cover plate 31 are within a reasonable range. This can reduce the possibility of the diaphragm of the electrode assembly 2 being folded due to the impact of the electrolyte on it, and also ensure that the electrolyte has a relatively fast injection efficiency. The larger the value of A / L2, the smaller the impact of the explosion-proof valve boss 323 on the outflow efficiency of the electrolyte flowing out of the outlet 3221. If A / L2 < 0.004, the distance between the outlet 3221 and the explosion-proof valve boss 323 is relatively close to the overall size of the top cover plate 31. The explosion-proof valve boss 323 may obstruct the electrolyte flowing out of the outlet 3221 to a certain extent, which may affect the electrolyte injection efficiency. If A / L2 > 0.5, the distance between the outlet 3221 and the explosion-proof valve boss 323 is relatively large compared to the overall size of the top cover plate 31. While this won't affect the electrolyte injection efficiency, it could prevent the production of the top cover assembly 3, resulting in insufficient space for the injection hole and the explosion-proof valve boss 323, thus hindering normal production. Therefore, controlling the distance between the explosion-proof valve boss 323 and the outlet 3221 within a reasonable range ensures good electrolyte injection efficiency and prevents diaphragm folding in the electrode assembly 2, improving the pass rate and safety of the secondary battery. Preferably, in some embodiments, along the second direction X, the minimum distance between the explosion-proof valve boss 323 and the outlet 3221 facing the explosion-proof valve boss 323, and the size of the top cover plate 31, satisfy: 0.04 ≤ A / L2 ≤ 0.39.

[0076] In some embodiments, along the second direction X, the minimum distance between the explosion-proof valve boss 323 and the outlet 3221 facing it satisfies: 2≤A≤50. For example, the value of A can be any one or any two values ​​of 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50. If A is too large, for the prismatic battery of this embodiment, the two electrode terminals 33, the explosion-proof valve, and the turbulence-disrupting part 322 cannot be properly arranged on the lower insulating member 32, which will prevent the top cover assembly 3 from being produced normally. If A is too small, the explosion-proof valve protrusion 323 will block the electrolyte flowing out of the outlet 3221, resulting in a decrease in the electrolyte flow rate, thereby affecting the electrolyte injection efficiency of the secondary battery. It should also be noted that if A is too small, the electrolyte may still have a relatively high speed after being blocked and changed direction by the explosion-proof valve protrusion 323, and may impact the electrode assembly 2. This may also cause the separator of the electrode assembly 2 to fold, thereby causing a short circuit inside the secondary battery. Furthermore, the minimum distance between the outlet 3221 and the explosion-proof valve protrusion 323 satisfies: 3≤A≤40.

[0077] It is understood that in this embodiment, both the electrode terminal 33 and the explosion-proof valve boss 323 are provided on the same top cover assembly 3. Therefore, the corresponding top cover piece 31 can be sized the same as in the aforementioned embodiments. Specifically, in some embodiments, the size of the top cover piece 31 along the second direction X satisfies: 100≤L2≤500. Preferably, in some embodiments, the size of the top cover piece 31 along the second direction X satisfies: 100≤L2≤250.

[0078] It should be noted that, in the embodiments of this application, some conventional dimensional measurement methods can be selected to obtain A and L2. For example, they can be measured directly using measuring tools such as vernier calipers and micrometers.

[0079] Please refer to the following: Figure 3 , Figure 4 and Figure 7 In some embodiments, the turbulence portion 322 has a cavity 3222, which is connected to the second injection hole 3211 and the outlet 3221 respectively.

[0080] In this embodiment of the application, by providing a cavity 3222 in the turbulence section 322, the electrolyte injected from the injection hole is contained in the cavity 3222, and the electrolyte is buffered and redirected so that the electrolyte flows out from the outlet 3221. At this time, it is possible to prevent the electrolyte from impacting and damaging the electrode assembly 2 inside the secondary battery. For example, by changing the direction of the electrolyte, it is possible to effectively prevent the separator from folding.

[0081] Please refer to the following: Figures 3-8 In some embodiments, the turbulence-disrupting part 322 includes a side plate 3223 and a baffle 3224. The side plate 3223 is disposed on the side of the body 321 away from the top cover plate 31 and connected to the body 321. The side plate 3223 is disposed on the outer periphery of the second injection hole 3211. The side plate 3223 has the liquid outlet 3221. The baffle 3224 is connected to the side of the side plate 3223 away from the body 321. Along the first direction Z, the baffle 3224 is spaced between the first injection hole 311 and the electrode assembly 2. The baffle 3224 and the side plate 3223 form the cavity 3222.

[0082] In this embodiment, a turbulence-inducing section 322 is formed by side plate 3223 and baffle 3224. The baffle 3224 is positioned opposite to the first injection hole 311 and the second injection hole 3211, effectively blocking and turbulent the electrolyte. The side plate 3223 further turbulentizes and concentrates the electrolyte, achieving directional electrolyte injection. Simultaneously, the side plate 3223 connects the baffle 3224 to the main body 321, ensuring structural stability. Furthermore, the side plate 3223 and baffle 3224 form a cavity 3222, which buffers the electrolyte. The outlet 3221 communicates with this cavity 3222, ensuring effective electrolyte injection.

[0083] In some embodiments, along the first direction Z, the area of ​​the side of the baffle 3224 facing the first injection hole 311 is S1 mm. 2 The opening area of ​​the first injection hole 311 is S2 mm. 2 The condition is satisfied that: 1.06≤S1 / S2≤10.

[0084] In this embodiment, the ratio between the area of ​​the orthographic projection of the side of the baffle 3224 facing the first injection hole 311 onto the body 321 and the opening area of ​​the first injection hole 311 satisfies 1.06≤S1 / S2≤10, and the baffle 3224 is arranged opposite to the first injection hole 311. At this time, the area of ​​the orthographic projection of the side of the baffle 3224 facing the first injection hole 311 onto the body 321 is greater than or equal to the area of ​​the first injection hole 311. This ensures that the baffle 3224 can effectively block the electrolyte injected into the first injection hole 311, preventing the electrolyte from directly impacting the electrode assembly 2 and causing the diaphragm to fold.

[0085] In this embodiment, the numerical range of S1 / S2 can be any one value or a range between any two values ​​from 1.06, 1.07, 1.08, 1.09, 1.1, 1.11, 1.12, 1.13, 1.14, 1.15, 1.18, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.8, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, and 10. The larger the value of S1 / S2, the larger the area of ​​the corresponding baffle 3224, the larger the blocking area for the electrolyte, and consequently the larger the protected area of ​​the electrode assembly 2, and the lower the probability of the diaphragm of the electrode assembly 2 folding. If the S1 / S2 value is too large, the area of ​​the baffle 3224 will be too large, which may lead to material waste, increase the weight of the battery, and prevent the electrolyte from smoothly and quickly penetrating into the electrode assembly 2. If the S1 / S2 value is too small, the baffle 3224 may not be able to completely block the first injection hole 311, which may pose a risk of diaphragm folding. Furthermore, in some embodiments, the area S1 mm of the orthographic projection of the side of the baffle 3224 facing the first injection hole 311 onto the body 321 is... 2 The opening area of ​​the first injection hole 311311 is S2 mm. 2 The condition is satisfied that 3≤S1 / S2≤8.

[0086] In some embodiments, the area of ​​the orthographic projection of the side of the baffle 3224 facing the first injection hole 311 onto the body 321 satisfies: 8.5≤S1≤60.

[0087] In this embodiment, the value of S1 can be any one of the following or a range between any two values: 8.5, 8.6, 8.7, 8.8, 8.9, 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 25, 30, 35, 40, 45, and 50. As S1 increases, the corresponding baffle 3224 provides better blocking effect against the electrolyte, allowing for greater folding of the membrane wall. However, an excessively large baffle 3224 can lead to material waste and even reduce the electrolyte injection effect.

[0088] In some embodiments, the opening area of ​​the first injection hole 311 satisfies: 6≤S2≤8.

[0089] In the embodiments of this application, the value of S2 can be any one of 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8 or any range between any two values.

[0090] It should be noted that the area S1 mm of the orthographic projection of the side of the baffle 3224 facing the first injection hole 311 onto the body 321 is... 2 The opening area of ​​the first injection hole 311311 is S2 mm. 2 If the area is a regular shape such as a rectangle, square, circle, trapezoid, or sector, it can be calculated by measuring the corresponding dimensions using the area measurement formula for that shape. If the area is an irregular shape, a film coating method can be used for measurement. That is, a uniformly sized film is placed over the first injection hole 311 and attached to its outer periphery. The film corresponding to the opening of the first injection hole 311 is removed, and the mass of the film is determined. The quotient of the removed film mass and the pre-determined mass per unit area of ​​the film is determined as the area of ​​the first injection hole 311 to be measured. Similarly, the film is attached to the body 321, and the side of the baffle 3224 facing the first injection hole 311 is projected onto the film. The part corresponding to the projection on the film is removed, and the mass of the film is determined. The quotient of the mass of the film and the mass of the pre-determined unit area of ​​the film is determined as the projection area of ​​the baffle 3224 facing the first injection hole 311 onto the body 321.

[0091] Please refer to the following: Figure 2 and Figure 3In some embodiments, the secondary battery has a third direction Y intersecting the second direction X, the electrode assembly 2 includes a tab 21, the tab 21 is electrically connected to the electrode terminal 33, and the side plate 3223 is spaced apart from the tab 21 along the third direction Y.

[0092] In this embodiment, by setting the side plate 3223 and the tab 21 at a distance along the third direction Y, or even setting them at a relative distance, it is possible to avoid the tab 21 partially blocking or interfering with the liquid outlet 3221. At the same time, the side plate 3223 can isolate the tab 21 from the cavity 3222, thus blocking the tab 21 and further preventing the tab 21 from short-circuiting with the top cover plate 31.

[0093] Please refer to the following: Figures 4-7 In some embodiments, the outlet 3221 penetrates the side plate 3223 along the first direction Z.

[0094] In this embodiment of the application, by setting the liquid outlet 3221 to penetrate the side plate 3223 along the first direction Z, it can ensure that the liquid outlet 3221 has a large flow area, and on the other hand, it can prevent the electrode liquid from accumulating in the cavity 3222 formed by the side plate 3223 and the baffle 3224, which is conducive to the rapid flow of electrolyte from the cavity 3222.

[0095] Please refer to the following: Figure 5 and Figure 8 In some embodiments, the side plate 3223 is arranged in an arc shape around the outer periphery of the second injection hole 3211.

[0096] In this embodiment, by setting the side plate 3223 to be curved around the outer periphery of the second injection hole 3211, the part of the side plate 3223 closest to the tab 21 is relatively far away from the outlet 3221 (the side plate 3223 is a straight plate). At this time, even if the tab 21 is relatively long or wide, the side plate 3223 can effectively block the tab 21, preventing the tab 21 from reaching the outlet 3221 and overlapping with the top cover plate 31 from the outlet 3221, thereby improving the safety of the secondary battery.

[0097] In one embodiment, the side plate 3223 includes a plurality of sub-plates 32231, which are circumferentially spaced around the second injection hole 3211. The sub-plates 32231 are connected to the body 321, and one end of the sub-plate 32231 away from the body 321 is connected to the baffle 3224. Two adjacent sub-plates 32231, the baffle 3224, and the body 321 form an outlet 3221.

[0098] In some embodiments, the side of the baffle 3224 facing the second injection hole 3211 is one of a plane, an arc surface protruding towards the second injection hole 3211, and a conical surface protruding towards the second injection hole 3211.

[0099] In this embodiment, the side of the baffle 3224 facing the second injection hole 3211 can be flat. Furthermore, the baffle 3224 can be entirely flat. This ensures that the baffle 3224 occupies as little space as possible between the core 22 and the top cover 31, providing sufficient size for the cavity 3222 to buffer the electrolyte. Simultaneously, the flat shape prevents electrolyte from accumulating inside the cavity 3222.

[0100] In this embodiment, the side of the baffle 3224 facing the second injection hole 3211 can be an arc surface protruding from the second injection hole 3211. At this time, the electrolyte can flow at an angle away from the second injection hole 3211 along the arc surface, which can directly change the direction of the electrolyte, making it easier for the electrolyte to flow out quickly from the outlet 3221, and can prevent the electrolyte from accumulating in the cavity 3222.

[0101] In this embodiment, the side of the baffle 3224 facing the second injection hole 3211 can be a conical surface protruding towards the second injection hole 3211. At this time, the apex of the conical surface is opposite to the second injection hole 3211. This can further reduce the obstruction of the electrolyte by the conical surface, allowing the electrolyte to change direction directly along the conical surface, improving the injection efficiency of the outlet 3221, and preventing the electrolyte from accumulating on the baffle 3224 and in the cavity 3222.

[0102] It is understood that the battery pack of this application embodiment includes all the technical features and effects of the aforementioned secondary battery, which will not be repeated here.

[0103] This application also provides an electrical device, including a secondary battery as described in any of the foregoing embodiments, or a battery pack as described in the foregoing embodiments.

[0104] It is understood that the electrical device in the embodiments of this application includes all the technical features and effects of the aforementioned secondary battery or battery pack, which will not be repeated here.

[0105] Of course, the electrical devices referred to in this application can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be new energy vehicles, including pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles; spacecraft include airplanes, rockets, space shuttles, and spacecraft; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. This application does not impose any special limitations on the above-mentioned electrical devices.

[0106] The secondary battery of this application will be described in detail below with reference to specific embodiments.

[0107] Example 1

[0108] Provides a secondary battery, including as follows Figure 7 and Figure 8 The flow-dissipating part 322, electrode terminal 33, and explosion-proof valve boss 323 shown are described. The minimum distance between the outlet 3221 of the flow-dissipating part 322 facing the explosion-proof valve boss 323 and the explosion-proof valve boss 323 is 39mm. The overall structure of the secondary battery is as follows: Figure 1 and Figure 2 As shown, the minimum distance L1 between the liquid outlet 3221 of the turbulence section 322 and the electrode terminal 33 and the electrode terminal 33 and the size L2 of the top cover plate 31 satisfy: 0.004≤L1 / L2≤0.5. For specific structural dimension parameters, please refer to Table 1.

[0109] Examples 2-7

[0110] A secondary battery is provided, with the same structure as in Embodiment 1, except that the minimum distance L1 between the liquid outlet 3221 of the turbulence section 322 and the electrode terminal 33 is different.

[0111] Examples 8-14

[0112] A secondary battery is provided, with the same structure as in Embodiment 1, except that the value of the size L2 of the top cover plate 31 is different.

[0113] Examples 15-16

[0114] A secondary battery is provided, with the same structure as in Embodiment 1, except that the minimum distance between the liquid outlet 3221 of the turbulence section 322 facing the electrode terminal 33 and the electrode terminal 33 is 2mm, and the size of the top cover plate 31 is different.

[0115] Examples 17-18

[0116] A secondary battery is provided, with the same structure as in Embodiment 1, except that the minimum distance L1 between the liquid outlet 3221 of the turbulence section 322 facing the electrode terminal 33 and the electrode terminal 33 is 50mm, and the size L2 of the top cover plate 31 is different.

[0117] Examples 19-24

[0118] A secondary battery is provided, with the same structure as in Embodiment 1, except that the minimum distance between the outlet 3221 of the turbulence-dispersing part 322 toward the electrode terminal 33 and the electrode terminal 33 is 39mm, the size of the top cover plate 31 is 150mm, and the minimum distance between the outlet 3221 of the turbulence-dispersing part 322 toward the explosion-proof valve boss 323 and the explosion-proof valve boss 323 is different.

[0119] Example 25

[0120] A secondary battery is provided, with the same structure as in Embodiment 1, except that the size of the top cover plate 31 is 500mm, and the minimum distance between the outlet 3221 of the turbulence part 322 facing the explosion-proof valve boss 323 and the explosion-proof valve boss 323 is different.

[0121] Examples 26-33

[0122] A secondary battery is provided, with the same structure as in Embodiment 1, and both satisfy the ranges of 0.004≤L1 / L2≤0.5, 0.004≤A / L2≤0.5, and 1.06≤S1 / S2≤10. The opening area of ​​the first injection hole 311 is 7.07 mm². 2 The difference lies in the fact that the area of ​​the orthographic projection of the side of the baffle 3224 facing the first injection hole 311 onto the body 321 is different.

[0123] Examples 34-38

[0124] A secondary battery is provided, with the same structure as in Embodiment 1, and both satisfy the ranges of 0.004≤L1 / L2≤0.5 and 0.004≤A / L2≤0.5. The area of ​​the side of the baffle 3224 facing the first injection hole 311 on the main body 321 is 50.24 mm². 2 The difference lies in the value of the opening area of ​​the first injection hole 311.

[0125] Examples 39-40

[0126] A secondary battery is provided, with the same structure as in Embodiment 1, and both satisfy the ranges of 0.004≤L1 / L2≤0.5 and 0.004≤A / L2≤0.5. The area of ​​the side of the baffle 3224 facing the first injection hole 311 on the main body 321 is 8.5mm². 2 The opening area of ​​the first injection hole 311 is different.

[0127] Examples 41-42

[0128] A secondary battery is provided, with the same structure as in Embodiment 1, and both satisfy the ranges of 0.004≤L1 / L2≤0.5 and 0.004≤A / L2≤0.5. The area of ​​the side of the baffle 3224 facing the first injection hole 311 on the main body 321 is 60mm². 2 The opening area of ​​the first injection hole 311 is different.

[0129] Comparative Examples 1-2

[0130] The specific structure is the same as in Example 1, except that the value of L1 / L2 does not satisfy the range of 0.004≤L1 / L2≤0.5, the value of A / L2 does not satisfy the range of 0.004≤A / L2≤0.5, and the value of S1 / S2 does not satisfy the range of 1.06≤S1 / S2≤10.

[0131] The specific experimental testing methods are as follows:

[0132] Separator folding: After the secondary battery is manufactured, it is disassembled. During the disassembly process, the electrode assembly 2 is opened to observe whether the separator inside the electrode assembly 2 has folded.

[0133] Electrolyte injection efficiency: A secondary battery according to an embodiment of this application is placed in an injection machine. The injection machine first evacuates the secondary battery to a pressure below -90 kPa. At this time, the electrolyte is already stored in the injection cup. Since the secondary battery is under negative pressure, the electrolyte flows into the secondary battery. Then, the injection machine performs alternating positive and negative pressure cycles on the secondary battery (positive pressure 180 kPa (30-60 s) negative pressure -60 kPa (3-15 s), cycled 4-12 times) to ensure that the electrolyte is fully injected into the secondary battery. The total injection time is t1 min. The same injection operation is performed on a secondary battery of the same specification without turbulence 322, and the total injection time is recorded as t2 min. If t1 / t2 ≥ 98%, it indicates that the injection efficiency meets the requirements.

[0134] Table 1

[0135]

[0136]

[0137]

[0138]

[0139] As shown in Table 1, the secondary batteries in Examples 1-18 all meet the range of 0.004≤L1 / L2≤0.5, which satisfies the requirement of preventing the separator of the electrode assembly from folding and achieving good electrolyte injection efficiency during electrolyte injection. A comparison between Examples 1-18 and Comparative Examples 1-2 shows that if L1 is too large or L2 is too small, the top cover assembly 3 may not be able to be produced normally. If L1 is too small or L2 is too large, the distance between the outlet 3221 and the electrode terminal 33 is too small, causing the electrode terminal 33 to obstruct the electrolyte flow from the outlet 3221, resulting in reduced electrolyte injection efficiency and a higher electrolyte flow rate between them, which can easily cause the separator to fold. Furthermore, even with a reasonable spacing, if the size L2 of the top cover plate 31 is small, the top cover assembly 3 may also not be able to be produced normally. As can be seen from Examples 8-14 and Examples 19-25, the secondary battery satisfies 0.004≤L1 / L2≤0.5 and 0.004≤A / L2≤0.5. Within this range, by reasonably controlling the values ​​of L1 and A, the secondary battery can have a better liquid injection efficiency.

[0140] As shown in Table 1, the secondary batteries in Examples 26-42, in addition to satisfying the ranges of 0.004≤L1 / L2≤0.5 and 0.004≤A / L2≤0.5, further satisfy 1.06≤S1 / S2≤10. Within this range, the electrolyte injection efficiency of the secondary battery can be guaranteed while preventing the separator from folding. Specifically, as the value of S1 / S2 increases, the electrolyte injection efficiency is relatively better, but the corresponding area of ​​S1 is relatively small. This reduces the blocking effect on the first injection hole, potentially leading to the risk of separator folding. If the S1 / S2 ratio is too large, although the possibility of separator folding is smaller, the corresponding blocking area is too large, which will affect the electrolyte injection efficiency of the secondary battery.

[0141] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0142] The foregoing has provided a detailed description of a secondary battery, battery pack, and power-consuming device provided in the embodiments of this application, and specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A secondary battery characterized by comprising: Having intersecting first and second directions, including: The shell has a receiving cavity; The electrode assembly is disposed within the receiving cavity; A top cover assembly includes a top cover sheet, a lower insulating member, and electrode terminals. The top cover sheet is connected to the housing and covers the receiving cavity. The top cover sheet has a first liquid injection hole. Along the first direction, the lower insulating member is connected to the side of the top cover sheet facing the electrode assembly. The electrode terminals pass through the top cover sheet and the lower insulating member and are electrically connected to the electrode assembly. The lower insulating element includes: The body is connected to the top cover plate, and the body has a second injection hole that communicates with the first injection hole; A flow-dispersing section is connected to the side of the body away from the top cover plate; along the first direction, at least a portion of the flow-dispersing section is spaced between the first injection hole and the electrode assembly; the flow-dispersing section and the electrode terminal are spaced apart along the second direction, and the flow-dispersing section has an outlet on the side facing the electrode terminal, the outlet communicating with the second injection hole; An explosion-proof valve boss is connected to the side of the body facing the electrode assembly; along the second direction, the explosion-proof valve boss is disposed on the side of the turbulence-disrupting part away from the electrode terminal, and the explosion-proof valve boss and the turbulence-disrupting part are spaced apart; the turbulence-disrupting part has a plurality of liquid outlets, and at least one of the liquid outlets is disposed facing the explosion-proof valve boss; Along the second direction, the minimum distance between the liquid outlet and the electrode terminal is L1 mm, and the size of the top cover plate is L2 mm, satisfying: 0.004≤L1 / L2≤0.5; along the second direction, the minimum distance between the liquid outlet and the electrode terminal satisfies: 2≤L1≤50; the size of the top cover plate satisfies: 100≤L2≤500.

2. The secondary battery according to claim 1, characterized by Along the second direction, the minimum distance between the liquid outlet and the electrode terminal, and the size of the top cover plate, satisfy: 0.04≤L1 / L2≤0.

39.

3. The secondary battery according to claim 1, characterized by Along the second direction, The minimum distance between the liquid outlet and the electrode terminal satisfies: 5 ≤ L1 ≤ 39; and / or, The dimensions of the top cover plate satisfy: 100≤L2≤250.

4. The secondary battery according to claim 1, characterized in that, Along the second direction, the minimum distance between the explosion-proof valve boss and the liquid outlet facing the explosion-proof valve boss is A mm, satisfying: 0.004 ≤ A / L² ≤ 0.5; or, Along the second direction, the minimum distance between the explosion-proof valve boss and the liquid outlet facing the explosion-proof valve boss, and the size of the top cover plate satisfy: 0.04≤A / L2≤0.

39.

5. The secondary battery according to claim 4, characterized by Along the second direction, The minimum distance between the explosion-proof valve boss and the outlet facing it satisfies: 2≤A≤50; and / or, The dimensions of the top cover plate satisfy: 100≤L2≤500.

6. The secondary battery according to claim 5, characterized by Along the second direction, The minimum distance between the explosion-proof valve boss and the outlet facing it satisfies: 5 ≤ A ≤ 39; and / or, The dimensions of the top cover plate satisfy: 100≤L2≤250.

7. The secondary battery according to claim 1, characterized by The turbulence section has a cavity, which is connected to the second injection hole and the outlet respectively.

8. The secondary battery according to claim 7, characterized by The flow-disrupting part includes: A side plate is disposed on the side of the body away from the top cover plate and connected to the body. The side plate is disposed on the outer periphery of the second injection hole. The side plate has the liquid outlet, which penetrates the side plate along the first direction. A baffle is connected to the side of the side plate away from the body. Along the first direction, the baffle is spaced between the first injection hole and the electrode assembly; the baffle and the side plate form the cavity.

9. The secondary battery according to claim 8, characterized by In the first direction, the area of the normal projection of the baffle plate on the body toward one side of the first liquid injection hole is S1 mm 2 , the opening area of the first liquid injection hole is S2 mm 2 , and the following condition is satisfied: 1.06≤S1 / S2≤10.

10. The secondary battery according to claim 9, characterized in that, The area of ​​the orthographic projection of the side of the baffle facing the first injection hole onto the main body satisfies: 8.5 ≤ S1 ≤ 60; and / or, The opening area of ​​the first injection hole satisfies: 6≤S2≤8.

11. The secondary battery according to claim 8, characterized by The secondary battery has a third direction intersecting the second direction, the electrode assembly includes tabs, the tabs are electrically connected to the electrode terminals, and the side plate and the tabs are spaced apart along the third direction.

12. The secondary battery according to claim 8, characterized in that, The side plate includes multiple sub-plates, which are arranged in an arc shape around the outer periphery of the second injection hole. The multiple sub-plates are spaced apart and connected to the main body. The end of the sub-plate away from the main body is connected to the baffle. Two adjacent sub-plates, the baffle, and the main body form a liquid outlet.

13. The secondary battery according to claim 9, characterized in that, The side of the baffle facing the second injection hole is one of a plane, an arc surface protruding towards the second injection hole, or a conical surface protruding towards the second injection hole.

14. A battery pack, characterized in that, Includes the secondary battery as described in any one of claims 1-13.

15. An electrical appliance, characterized in that, Includes the secondary battery as described in any one of claims 1-13, or the battery pack as described in claim 14.

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