Secondary battery, battery pack, and electric device

Abstract

The utility model discloses a secondary battery, a battery pack and a power utilization device, the secondary battery has a first direction and comprises a shell, an electrode assembly and a top cover assembly, the top cover assembly comprises a top cover piece and a lower insulating part, the top cover piece is provided with a first liquid injection hole, and the lower insulating part is arranged on one side, facing the electrode assembly, of the top cover piece; the lower insulating part comprises a body, a side plate and a baffle plate, the body is connected with the top cover sheet, and the body is provided with a second liquid injection hole communicated with the first liquid injection hole; the side plate is connected to the side, away from the top cover piece, of the body and located on the peripheral side of the second liquid injection hole. The baffle is connected to the side, away from the body, of the side plate and is opposite to the second liquid injection hole. The side plate is provided with a liquid outlet communicated with the second liquid injection hole; in the first direction, the end, close to the body, of the side plate inclines in the direction away from the axis of the second liquid injection hole. The projection area of the side, facing the first liquid injection hole, of the baffle on the body is S1, the opening area of the first liquid injection hole is S2, and S1 / S2 is larger than or equal to 1.06 and smaller than or equal to 10.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a secondary battery, a battery pack and a power utilization device. BACKGROUND

[0002] In the production process of a secondary battery, electrolyte is injected into the shell. In the electrolyte injection process, the hydraulic pressure is large, so the impact on the electrode assembly inside the battery is large, which is easy to cause the diaphragm of the electrode assembly to be folded, and further causes internal short circuit of the battery. CONTENT OF THE UTILITY MODEL

[0003] The utility model aims at solving the problem that the existing secondary battery is easy to cause the diaphragm to be folded when injecting electrolyte, and further causes internal short circuit of the secondary battery. Another object of the application is to provide a battery pack. Another object of the application is to provide a power utilization device.

[0004] TECHNICAL SCHEME: The secondary battery provided by the application has a first direction and comprises:

[0005] A shell has a receiving cavity.

[0006] An electrode assembly is arranged in the receiving cavity.

[0007] A top cover assembly comprises a top cover sheet and a lower insulating piece. The top cover sheet is connected with the shell and covers the receiving cavity. The top cover sheet has a first liquid injection hole. The lower insulating piece is arranged on the side of the top cover sheet facing the electrode assembly.

[0008] The lower insulating piece comprises:

[0009] A body is connected with the top cover sheet. The body is provided with a second liquid injection hole communicating with the first liquid injection hole.

[0010] A side plate is arranged on the side of the body away from the top cover sheet and is connected with the body. The side plate is arranged on the outer circumferential side of the second liquid injection hole.

[0011] A baffle is connected to the side of the side plate away from the body. The baffle is arranged opposite to the second liquid injection hole. The side plate has a liquid outlet communicating with the second liquid injection hole. In the first direction, the end of the side plate close to the body is arranged to be inclined toward the direction away from the axis of the second liquid injection hole.

[0012] The area of the normal projection of the side of the baffle facing the first liquid injection hole on the body is S1 mm 2 The opening area of the first liquid injection hole is S2 mm 2 , and satisfies 1.06≤S1 / S2≤10.

[0013] In some embodiments, the area of the baffle plate on the body in the orthographic projection towards the first liquid injection hole, and the opening area of the first liquid injection hole satisfy: 6≤S1 / S2≤9.

[0014] In some embodiments,

[0015] The area of the baffle plate on the body in the orthographic projection towards the first liquid injection hole satisfies: 8.5≤S1≤60; and / or,

[0016] The opening area of the first liquid injection hole satisfies: 6≤S2≤8.

[0017] In some embodiments, along the first direction, the angle of the end of the side plate close to the body tilting towards the direction away from the axis of the second liquid injection hole is β°, satisfying: 0<β<90.

[0018] In some embodiments, along the first direction, the angle of the end of the side plate close to the body tilting towards the direction away from the axis of the second liquid injection hole satisfies: 30≤β≤60.

[0019] In some embodiments, along the direction of the side plate extending towards the body, the liquid outlet penetrates the side plate, and the side plate, the baffle plate and the body enclose the liquid outlet.

[0020] In some embodiments, the side plate has a plurality of liquid outlets, and the plurality of liquid outlets are arranged at intervals along the circumference of the side plate, and the plurality of liquid outlets are all in communication with the second liquid injection hole.

[0021] In some embodiments, the side plate comprises a plurality of sub-plates, and the plurality of sub-plates are arranged at intervals along the circumference of the baffle plate, the sub-plates are connected to the body, the end of the sub-plate away from the body is connected to the baffle plate, and adjacent two sub-plates and the baffle plate and the body enclose one liquid outlet.

[0022] In some embodiments, the secondary battery has a second direction intersecting the first direction, the top cover assembly comprises an electrode terminal, the electrode terminal is provided through the top cover sheet and the body, the electrode terminal and the side plate are arranged at intervals along the second direction; the lower insulating piece comprises an explosion-proof valve boss, the explosion-proof valve boss is connected to the side of the body away from the top cover sheet; along the second direction, the explosion-proof valve boss is arranged on the side of the side plate away from the electrode terminal, and the explosion-proof valve boss and the side plate are arranged at intervals; at least one liquid outlet is arranged towards the electrode terminal, and at least one liquid outlet is arranged towards the explosion-proof valve boss.

[0023] In some embodiments, the flow area of the liquid outlet is S3 mm 2 The outer surface area of the side plate is S4 mm 2 0.04≤S3 / S4≤3.

[0024] In some embodiments, the flow area of the liquid outlet is S3 mm 2 The outer surface area of the side plate is S4 mm 2 0.3≤S3 / S4≤1.

[0025] In some embodiments,

[0026] The flow area of the liquid outlet satisfies: 12≤S3≤150; and / or,

[0027] The outer surface area of the side plate satisfies: 50≤S4≤300.

[0028] In some embodiments,

[0029] The flow area of the liquid outlet satisfies: 40≤S3≤130; and / or,

[0030] The outer surface area of the side plate satisfies: 150≤S4≤200.

[0031] In some embodiments, the side surface of the baffle plate facing the second liquid injection hole is one of a plane perpendicular to the axis, a circular arc surface convex toward the second liquid injection hole, and a circular conical surface convex toward the second liquid injection hole.

[0032] Correspondingly, the battery pack according to an embodiment of the application comprises the secondary battery according to any one of the preceding embodiments.

[0033] Correspondingly, the power consumption device according to an embodiment of the application comprises the secondary battery according to any one of the preceding embodiments, or the battery pack according to the preceding embodiments.

[0034] Beneficial effects: compared with the prior art, the secondary battery of the embodiment of the application has a first direction, including a shell, an electrode assembly and a top cover assembly, the shell has a containing cavity, the electrode assembly is arranged in the containing cavity, the top cover assembly includes a top cover sheet and a lower insulating piece, the top cover sheet is connected with the shell and covers and seals the containing cavity, the top cover sheet has a first liquid injection hole; the lower insulating piece is arranged on a side of the top cover sheet facing the electrode assembly; the lower insulating piece includes a body, a side plate and a baffle, the body is connected with the top cover sheet, the body is provided with a second liquid injection hole in communication with the first liquid injection hole; the side plate is arranged on a side of the body away from the top cover sheet and is connected with the body, the side plate is arranged on a peripheral side of the second liquid injection hole; the baffle is connected to a side of the side plate away from the body, and the baffle is arranged opposite to the second liquid injection hole; the side plate has a liquid outlet, and the liquid outlet is in communication with the second liquid injection hole; along the first direction, an end of the side plate close to the body is inclined toward a direction away from the second liquid injection hole; wherein a projection area of the side of the baffle facing the first liquid injection hole on the body is S1 mm 2 , an opening area of the first liquid injection hole is S2 mm 2 , and 1.06≤S1 / S2≤10 is met. By arranging the side plate and the baffle, the application realizes the change of the flow direction of the electrolyte after injection, avoids the direct impact of the electrolyte on the electrode assembly, prevents the electrolyte diaphragm from folding, controls the ratio of the projection area of the side of the baffle facing the first liquid injection hole on the body to the opening area of the first liquid injection hole to meet 1≤S1 / S2≤10, effectively guarantees the blocking and disturbance efficiency of the baffle to the electrolyte, improves the reliability of preventing the diaphragm from folding, thereby avoiding the occurrence of dangerous conditions such as internal short circuit of the battery, and can guarantee good liquid injection efficiency; in addition, by inclining the end of the side plate close to the body toward the direction away from the second liquid injection hole, the area of the baffle can be adjusted according to requirements on the basis of guaranteeing the unchanged diameter of the second liquid injection hole, thereby reducing the production difficulty of the lower insulating piece.

[0035] Compared with the prior art, the battery pack of the embodiment of the application includes the secondary battery as described in any one of the preceding embodiments. It can be understood that the battery pack of the embodiment of the application includes all the technical features and technical effects of the preceding secondary battery, which will not be described here.

[0036] Compared with the prior art, the power device of the embodiment of the application includes the secondary battery as described in any one of the preceding embodiments, or the battery pack as described in the preceding embodiments. It can be understood that the power device of the embodiment of the application includes all the technical features and technical effects of the preceding secondary battery or battery pack, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0038] Figure 1 is a structural schematic diagram of a secondary battery according to an embodiment of the present application;

[0039] Figure 2 is an exploded view of a secondary battery according to an embodiment of the present application;

[0040] Figure 3 is a structural schematic diagram of a top cover assembly of a secondary battery according to an embodiment of the present application;

[0041] Figure 4 is a bottom view of a top cover assembly of a secondary battery according to an embodiment of the present application;

[0042] Figure 5 is a structural schematic diagram of a top cover assembly of a secondary battery according to an embodiment of the present application; Figure 4 is an enlarged view of part A in

[0043] Figure 6 is a sectional view of a secondary battery according to an embodiment of the present application along a first direction and a second direction;

[0044] Figure 7 is a sectional view of a secondary battery according to an embodiment of the present application along a first direction and a second direction; Figure 6 is an enlarged view of part B in

[0045] Figure 8 is a sectional view of a secondary battery according to an embodiment of the present application along a direction perpendicular to the second direction;

[0046] Figure 9 is an enlarged view of part C in Figure 8

[0047] Reference signs: 1, housing; 11, accommodating cavity; 2, electrode assembly; 21, tab; 22, roll core; 3, top cover assembly; 31, top cover sheet; 311, first liquid injection hole; 32, lower insulating member; 321, body; 3211, second liquid injection hole; 3212, axis; 322, side plate; 3221, liquid outlet; 3222, sub-plate; 323, baffle; 324, cavity; 325, anti-explosion valve boss; 33, electrode terminal; Z, first direction; X, second direction. DETAILED DESCRIPTION

[0048] ​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.

[0049] 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.

[0050] It should also be noted that in the accompanying drawings of this application, an arrow labeled Z indicates the first direction Z, and an arrow labeled X indicates the second direction X. The introduction of the first direction Z and the second direction X is to facilitate the description of the structural positional relationship of the secondary battery, thereby making its structure easier to understand. In the embodiments of this application, the first direction Z is the height direction of the secondary battery, and the second direction X is the length direction of the secondary battery; furthermore, the first direction Z and the second direction X intersect, and more specifically, the first direction Z and the second direction X are perpendicular.

[0051] 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.

[0052] In view of this, embodiments of this application provide a secondary battery to solve the above problems.

[0053] Please refer to the following: Figures 1-3 , Figures 6-9 A secondary battery according to an embodiment of this application has a first direction Z and includes 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 and a lower insulating member 32. 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. The lower insulating member 32 is disposed on the side of the top cover plate 31 facing the electrode assembly 2. The lower insulating member 32 includes a body 321, a side plate 322, and a baffle 323. The body 321 is connected to the top cover plate 31, and the body 321 has a second liquid injection hole 321 communicating with the first liquid injection hole 311. 1; Side plate 322 is disposed on the side of body 321 away from top cover plate 31 and connected to body 321, side plate 322 is disposed on the outer periphery of second injection hole 3211; baffle 323 is connected to the side of side plate 322 away from body 321, baffle 323 is disposed opposite to second injection hole 3211; side plate 322 has liquid outlet 3221, liquid outlet 3221 communicates with second injection hole 3211; along the first direction Z, the end of side plate 322 near body 321 is inclined in the direction away from second injection hole 3211; wherein, the side of baffle 323 facing first injection hole 311 has a projected area of ​​S1 mm on body 321. 2 The opening area of ​​the first injection hole 311 is S2 mm. 2 The condition is satisfied that: 1.06≤S1 / S2≤10.

[0054] In this embodiment, by setting the side plate 322 and the baffle 323, the flow direction of the electrolyte after injection is changed, avoiding direct impact of the electrolyte on the electrode assembly 2 and preventing the electrolyte diaphragm from folding. Simultaneously, by controlling the ratio of the projected area of ​​the side of the baffle 323 facing the first injection hole 311 on the body 321 to the opening area of ​​the first injection hole 311 to satisfy 1≤S1 / S2≤10, the efficiency of the baffle 323 in blocking and turbulenting the electrolyte is effectively guaranteed, improving the reliability of preventing diaphragm folding and thus avoiding dangerous situations such as internal short circuits in the battery; it also ensures good injection efficiency. Furthermore, by setting the end of the side plate 322 near the body 321 to be tilted away from the second injection hole 3211, the area of ​​the baffle 323 can be adjusted according to requirements while keeping the diameter of the second injection hole 3211 unchanged, thereby reducing the manufacturing difficulty of the lower insulating component 32.

[0055] Specifically, in this embodiment, the side plate 322 is spaced between the body 321 and the baffle 323, so that the baffle 323 and the second injection hole 3211 are opposite and spaced apart, and the baffle 323 and the first injection hole 311 are also opposite and spaced apart. The side plate 322 is disposed on the outer periphery of the second injection hole 3211 to prevent the side plate 322 from blocking the second injection hole 3211. The side plate 322 has an outlet 3221 for leading the electrolyte injected from the first injection hole 311 into the receiving cavity 11 to wet the electrode assembly 2. It can be understood that the side plate 322 and the baffle 323 directly enclose a cavity 324, which is used to buffer the electrolyte, which is equivalent to setting a space between the baffle 323 and the first injection hole 311 to buffer the electrolyte. The baffle 323 is positioned opposite to and spaced apart from the first injection hole 311. On the one hand, it provides space for the electrolyte to flow out from the first injection hole 311, enabling rapid injection of the electrolyte. On the other hand, by using the baffle 323 to separate the first injection hole 311 and the electrode assembly 2, it can effectively block the electrolyte and protect the electrode assembly 2, effectively preventing the separator of the electrode assembly 2 from folding and avoiding direct short circuit between adjacent electrodes of the electrode assembly 2 due to the lack of separator isolation and insulation. This can improve the safety of the secondary battery.

[0056] It should be noted that in this embodiment, the end of the side plate 322 near the body 321 is tilted away from the second injection hole 3211. This allows the side plate 322 to partially obstruct and turbulent the electrolyte injected from the first injection hole 311 and flowing out through the second injection hole 3211. The combination of the side plate 322 and the baffle 323 effectively increases the turbulence area and range, further reducing the possibility of diaphragm folding and thus improving battery safety. Furthermore, the tilted side plate 322 also partially shields the portion of the top cover plate 31 exposed from the second injection hole 3211. Even if the baffle 323 has a small area, the side plate 322 can still reduce the area of ​​the top cover plate 31 exposed from the side plate 322, thereby reducing the risk of the tab 21 entering the second injection hole from the outlet 3221 and short-circuiting with the top cover plate 31. This further improves the safety of the secondary battery.

[0057] It should also be noted that, in this embodiment, by setting the ratio between the area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 on the body 321 and the opening area S2 of the first injection hole 311, the ratio satisfies 1≤S1 / S2≤10. The baffle 323 is opposite to and spaced apart from the first injection hole 311. At this time, the area of ​​the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 on the body 321 is greater than or equal to the area of ​​the first injection hole 311. This ensures that the baffle 323 can effectively block the electrolyte injected into the first injection hole 311, and prevent the electrolyte from directly impacting the electrode assembly 2 and causing the diaphragm to fold. The value of S1 / S2 can be any one or 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. A larger S1 / S2 value corresponds to a larger area of ​​baffle 323, a larger blocking area for the electrolyte, and consequently a larger protective area for electrode assembly 2, thus reducing the likelihood of diaphragm folding in electrode assembly 2. If the value of S1 / S2 is too large, the area of ​​the baffle 323 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 value of S1 / S2 is too small, the baffle 323 may not be able to completely cover the first injection hole 311, which may pose a risk of diaphragm folding. Furthermore, in some embodiments, the projected area S1 of the side of the baffle 323 facing the first injection hole 311 on the body 321 and the opening area S2 of the first injection hole 311 satisfy: 6≤S1 / S2≤9.

[0058] In some embodiments, the orthogonal projection area S1 of the side of the baffle 323 facing the first injection hole 311 on the body 321 satisfies: 8.5≤S1≤60.

[0059] 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 3233224 has a better blocking effect on the electrolyte, allowing for maximum folding of the wall diaphragm. However, an excessively large baffle 3233224 can lead to material waste and even reduce the electrolyte injection effect.

[0060] In some embodiments, the opening area S2 of the first injection hole 311 satisfies: 6≤S2≤8.

[0061] In this embodiment, 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, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, or 8, or a range between any two values. The first injection hole 311 can be adjusted according to the size of the injection nozzle of the external injection device. The larger the opening area of ​​the first injection hole 311, the faster the injection speed and the higher the injection efficiency.

[0062] It should be noted that the opening area of ​​the first injection hole 311 needs to be less than or equal to the opening area of ​​the second injection hole 3211, so as to avoid the hole wall of the second injection hole 3211 from blocking the first injection hole 311, thus avoiding the hole wall of the second injection hole 3211 from affecting the main rate of the first injection hole 311.

[0063] It should also be noted that the area S1 mm of the orthographic projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 2 The opening area of ​​the first injection hole 311 is S2 mm. 2If 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 of a unit area of ​​the film is determined as the area S2 of the first injection hole 311 being measured. Similarly, the film is attached to the body 321, and the side of the baffle 323 facing the first injection hole 311 is projected onto the film. The portion corresponding to the projected portion of the film is removed, and the mass of that piece of film is determined. The quotient of the film mass and the pre-determined mass of a unit area of ​​the film is determined as the projected area of ​​the side of the baffle 323 facing the first injection hole 311 onto the body 321.

[0064] like Figure 7 As shown, in some embodiments, along the first direction Z, the end of the side plate 322 near the body 321 is tilted at an angle of β° toward the axis 3212 away from the second injection hole 3211, satisfying: 0 < β < 90.

[0065] In this embodiment, by tilting the end of the side plate 322 near the body 321 toward the axis 3212 away from the second injection hole 3211, the size of the baffle 323 can be adjusted while facilitating the production of the lower insulating component 32. Specifically, the larger the angle β of the tilt of the end of the side plate 322 near the body 321 toward the axis 3212 away from the second injection hole 3211, the smaller the area of ​​the corresponding baffle 323. With the distance between the baffle 323 and the body 321 remaining constant, the flow area of ​​the corresponding outlet 3221 also increases, further improving the electrolyte injection efficiency.

[0066] Specifically, it should be noted that the lower insulating part 32 is a normally insulating injection molded part. During the production of the lower insulating part 32, the lower insulating part 32 can be integrally injection molded in the mold. In this case, it is preferable to set a side plate 322 connected to the edge of the hole wall of the second injection hole 3211. The side of the side plate 322 near the cavity 324 has a smooth transition with the hole wall of the second injection hole 3211. Relative to the side of the side plate 322 near the axis 3212 of the second injection hole 3211 (at this time, it is equivalent to the body 321 participating in the formation of the cavity 324. During demolding, the body 321 will cause obstruction and is not conducive to demolding), this is conducive to the demolding of the lower insulating part 32.

[0067] It should be noted that, in the embodiments of this application, the value of β can be any one of the following or a range between any two values: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 20, 23, 25, 28, 30, 33, 35, 38, 40, 43, 45, 48, 50, 52, 55, 58, 60, 65, 70, 75, 80, 85, 89. Wherein, while keeping the distance between the baffle 323 and the body 321 along the first direction Z constant, the larger the value of β, the smaller the area of ​​the orthographic projection of the side of the baffle 323 facing the first injection hole 311 on the plane of the body 321, and the smaller the corresponding blocking area of ​​the first injection hole 311. At this time, the efficiency of electrolyte injection will also be higher; correspondingly, the effect of the baffle 323 in preventing the diaphragm from folding will also be reduced. When the value of β is too large, the area of ​​the orthographic projection of the side of the baffle 323 facing the first injection hole 311 on the plane of the body 321 may be smaller than the area of ​​the first injection hole 311. However, the side plate 322 will be partially positioned opposite the first injection hole 311, which can also block and turbulent the electrolyte injected into the first injection hole 311, and can also achieve the technical effect of preventing the diaphragm from folding. In this case, the injection efficiency may be higher. Furthermore, in some embodiments, along the first direction Z, the angle β of the side plate 322 near the body 321 towards the axis 3212 away from the second injection hole 3211 satisfies: 30≤β≤60.

[0068] It should be noted that the angle β of the inclination of the side plate 322 near the body 321 towards the axis 3212 away from the second injection hole 3211 can be measured by cutting open the lower insulating part along the axis 3212 to open the cavity 324, at which point a protractor can be used to directly measure the inclination angle of the side plate. Alternatively, a level and ruler can be used: first, place the level on the edge of the side plate to determine the horizontal baseline, then use a ruler to measure the vertical distance from the horizontal baseline to the side plate and the length of the horizontal baseline, and calculate the inclination angle using trigonometric functions. Photogrammetry can also be used: take a picture of the side plate, and then calculate the angle in image processing software using a reference object of known size and the image of the side plate.

[0069] Please refer to the following: Figures 3-9 In some embodiments, the liquid outlet 3221 extends through the side plate 322 in the direction of the side plate 322 toward the body 321, and the side plate 322, the baffle 323 and the body 321 form the liquid outlet 3221.

[0070] In this embodiment, by setting the outlet 3221 to penetrate the side plate 322 along the first direction Z, it is possible to ensure that the outlet 3221 has a large flow area and to prevent the electrolyte from accumulating in the cavity 324 formed by the side plate 322 and the baffle 323. This facilitates the rapid outflow of the electrolyte from the cavity 324, thus ensuring the electrolyte injection efficiency and achieving the expected injection effect.

[0071] Please refer to the following: Figure 3 , Figure 4 , Figure 5 , Figure 7 and Figure 9 In some embodiments, the side plate 322 has a plurality of liquid outlets 3221, which are spaced apart along the circumference of the side plate 322, and all of the liquid outlets 3221 are connected to the second injection hole 3211.

[0072] In this embodiment, by providing multiple outlets 3221, electrolyte can flow out simultaneously from multiple directions, thus further improving the electrolyte injection efficiency. Preferably, there can be three or more outlets 3221, which allows the electrolyte to diffuse out from multiple directions, thereby reducing the impact force of the electrolyte in a certain direction and ensuring the stability of the battery's internal structure.

[0073] Please refer to the following: Figure 5 and Figure 9 In some embodiments, the side plate 322 includes a plurality of sub-plates 3222, which are circumferentially spaced around the baffle 323. The sub-plates 3222 are connected to the body 321, and the end of the sub-plate 3222 away from the body 321 is connected to the baffle 323. Two adjacent sub-plates 3222, the baffle 323, and the body 321 form a liquid outlet 3221.

[0074] In this embodiment, multiple sub-plates 3222 are connected to baffles 323 and the main body 321 to form multiple liquid outlets 3221. The sub-plates 3222 are respectively connected to the edges of baffles 323 and the main body 321. At this time, the electrolyte injected into the cavity 324 can flow out fully from the liquid outlets 3221, effectively preventing electrolyte accumulation in the cavity 324. At the same time, the multiple liquid outlets 3221 cooperate to divert the electrolyte, thereby reducing the impact force of the electrolyte flowing out of a single liquid outlet 3221 and effectively reducing damage to the internal structure of the battery.

[0075] In some embodiments, the flow area of ​​the outlet 3221 is S3 mm. 2 The outer surface area of ​​side panel 322 is S4 mm. 2 The condition is satisfied that: 0.04≤S3 / S4≤3.

[0076] It should be noted that, in the embodiments of this application, the numerical range of S1 / S2 can be 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0 The range of any one or any two values ​​from 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.1, 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, 2.6, 2.7, 2.8, 2.9, 3.

[0077] In this embodiment, the larger the flow area of ​​the outlet 3221, the higher the electrolyte injection efficiency. Therefore, within the allowable range, the larger the flow area of ​​the outlet 3221, the better. This embodiment sets the flow area S3 of the outlet 3221 and the outer surface area S4 of the side plate 322 to satisfy: 0.04 ≤ S3 / S4 ≤ 3. This ensures that the outlet 3221 has an effective electrolyte dispensing effect, guaranteeing good electrolyte injection efficiency for the battery. As the ratio of S3 / S4 increases, the corresponding electrolyte injection efficiency is higher. When the ratio of S3 / S4 is too small, the dispensing efficiency of the outlet 3221 decreases, and the electrolyte injection efficiency also decreases. When the ratio of S3 / S4 is too large, the outer surface area of ​​the corresponding side plate 322 is smaller. This means the side plate 322 will either have a smaller circumferential dimension, which may lead to breakage under electrolyte impact; or the side plate 322 will have a smaller dimension along the first direction Z, resulting in an excessively small dimension of the outlet 3221 along the first direction Z, leading to excessive resistance from the baffle 323 to the electrolyte. Therefore, in this embodiment, the ratio of S3 / S4 is set to 0.04 ≤ S3 / S4 ≤ 3. This ensures both electrolyte injection efficiency and structural stability while preventing diaphragm folding through the baffle 323. Furthermore, in some embodiments, the flow area S3 mm of the outlet 3221 is... 2 The outer surface area of ​​side panel 322 is S4 mm. 2 The condition is satisfied that: 0.3≤S3 / S4≤1.

[0078] In some embodiments, the flow area S3 of the outlet 3221 satisfies: 12≤S3≤150.

[0079] In this embodiment, the flow area S3 of the outlet 3221 can be any one or any two values ​​from 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, and 150. A larger S3 value corresponds to a higher electrolyte injection efficiency, while a smaller S3 value corresponds to higher structural stability of the lower insulating component 32. Further, the preferred range for the flow area S3 of the outlet 3221 is: 40 ≤ S3 ≤ 130.

[0080] In some embodiments, the outer surface area S4 of the side plate 322 satisfies: 50≤S4≤300.

[0081] In this embodiment, the numerical range of the outer surface area S4 of the side plate 322 can be 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 1 The value of S4 is any one or any two values ​​from the ranges of 00, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, and 300. A larger value of S4 corresponds to a lower electrolyte injection efficiency but better structural stability; a smaller value of S4 corresponds to a higher electrolyte injection efficiency. Furthermore, the preferred range for the outer surface area S4 of the side plate 322 is: 150 ≤ S4 ≤ 200.

[0082] It should be noted that in the embodiments of this application, S3 and S4 can be measured using the same measurement method as S1 and S2, which will not be repeated here.

[0083] In some embodiments, the side of the baffle 323 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.

[0084] In this embodiment, the side of the baffle 323 facing the second injection hole 3211 can be flat, and further, the baffle 323 can be a flat plate structure. In this case, it can be ensured that the baffle 323 occupies as little space as possible between the electrode assembly 2 and the body 321, providing sufficient size for the cavity 324 to buffer the electrolyte. At the same time, the flat plate shape can prevent the electrolyte from accumulating in the cavity 324.

[0085] In this embodiment, the side of the baffle 323 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 and make it easier for the electrolyte to flow out quickly from the outlet 3221, further improving the injection efficiency of the electrolyte and preventing the electrolyte from accumulating in the cavity 324.

[0086] In this embodiment, the side of the baffle 323 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 323 and in the cavity 324.

[0087] Accordingly, this application also provides a battery pack, including a secondary battery as described in any of the foregoing embodiments.

[0088] It is understood that the battery pack in this application embodiment includes all the technical features and effects of the aforementioned secondary battery, which will not be repeated here.

[0089] Accordingly, 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.

[0090] 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.

[0091] 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.

[0092] The secondary battery of this application will be described in detail below with reference to specific embodiments.

[0093] Example 1

[0094] Provides a secondary battery, including as follows Figures 3-9 The top cover 31 and lower insulating member 32 are shown. The top cover 31 has a first liquid injection hole 311, and the lower insulating member 32 includes a body 321, a baffle 323, and a side plate 322. The overall structure of the secondary battery is as follows: Figure 1 As shown, the end of the side plate 322 closest to the body 321 is inclined at an angle of 45 degrees toward the axis 3212 away from the second injection hole 3211, and the flow area S3 of the outlet 3221 is 100 mm². 2 The outer surface area S4 of side panel 322 is 200mm². 2 The ratio of the area S1 of the orthographic projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 to the opening area S2 of the first injection hole 311 satisfies: 1.06≤S1 / S2≤10. For specific structural dimension parameters, please refer to Table 1.

[0095] Example 2-10

[0096] A secondary battery is provided, with the same structure as in Embodiment 1, except that the area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 is different.

[0097] Examples 11-16

[0098] A secondary battery is provided, with the same structure as in Embodiment 1, except that the opening area S2 of the first injection hole 311 is different.

[0099] Examples 17-18

[0100] A secondary battery is provided, with the same structure as in Embodiment 1, except that the area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 is 8.5 mm². 2 The opening area S2 of the first injection hole 311 has different values.

[0101] Examples 19-20

[0102] A secondary battery is provided, with the same structure as in Embodiment 1, except that the area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 is 60 mm². 2 The opening area S2 of the first injection hole 311 has different values.

[0103] Comparative Examples 1-2

[0104] A secondary battery is provided, with the same structure as in Embodiment 1, except that the area S1 of the orthographic projection of the side of the baffle 323 facing the first injection hole 311 on the body 321 and the opening area S2 of the first injection hole 311 are different and do not satisfy the range of 1.06≤S1 / S2≤10.

[0105] The specific experimental testing methods are as follows:

[0106] 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.

[0107] 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 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 baffle 323 and side plate 322. The total injection time is recorded as t2 min. If t1 / t2 ≥ 98%, it indicates that the injection efficiency meets the requirements.

[0108] Table 1

[0109]

[0110]

[0111]

[0112] As shown in Table 1, the secondary batteries in Examples 1-20 all meet the range of 1.06 ≤ S1 / S2 ≤ 10, thus satisfying the requirements for preventing separator folding and improving electrolyte injection efficiency. A comparison between Examples 1-20 and Comparative Examples 1-2 shows that if S1 is too large or S2 is too small, the electrolyte injection efficiency will decrease, which is detrimental to improving production efficiency. If S1 is too small or S2 is too large, there is a risk of separator folding.

[0113] Examples 21-31

[0114] A secondary battery is provided, with the same structure as in Embodiment 1. The area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 is 50.24 mm². 2 The opening area S2 of the first injection hole 311 is 7.07 mm. 2 All of them satisfy the range of 1.06≤S1 / S2≤10. The flow area S3 of the outlet 3221 is 100mm2, and the outer surface area S4 of the side plate 322 is 200mm2. The difference is that the angle β of the side plate 322 inclined towards the axis 3212 away from the second injection hole 3211 at the end close to the body 321 is different.

[0115] Comparative Examples 3-4

[0116] A secondary battery is provided, with the same structure as in Embodiment 1. The difference is that the area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 and the opening area S2 of the first injection hole 311 are different, and neither of them satisfies the range of 1.06≤S1 / S2≤10. At the same time, the range of β does not satisfy 0<β<90.

[0117] The specific data and test results of Examples 1, Examples 21-31 and Comparative Examples 3-4 are shown in Table 2. The test process corresponding to the test results in Table 2 is the same as that in Table 1.

[0118] Table 2

[0119]

[0120]

[0121] As shown in Table 2, the secondary batteries in Examples 21-31, while satisfying the condition 1.06≤S1 / S2≤10, further satisfy 0<β<90. In this case, the electrolyte injection efficiency of the secondary battery can be further adjusted by adjusting the tilt angle of the side plate 322. However, it is necessary to avoid an excessively large β angle, otherwise production may be impossible.

[0122] Examples 32-36

[0123] A secondary battery is provided, with the same structure as in Embodiment 1. The area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 is 50.24 mm². 2 The opening area S2 of the first injection hole 311 is 7.07 mm. 2 All of them satisfy the range of 1.06≤S1 / S2≤10 and the range of 0.04≤S3 / S4≤3. The side plate 322 is inclined at an angle of 45 degrees toward the axis 3212 away from the second injection hole 3211 at the end close to the body 321. The difference is that the value of the flow area S3 of the outlet 3221 is different.

[0124] Examples 37-42

[0125] A secondary battery is provided, with the same structure as in Embodiment 1. The area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 is 50.24 mm². 2 The opening area S2 of the first injection hole 311 is 7.07 mm. 2 All of them satisfy the range of 1.06≤S1 / S2≤10 and the range of 0.04≤S3 / S4≤3. The side plate 322 is inclined at an angle of 45 degrees toward the axis 3212 away from the second injection hole 3211 at the end close to the body 321. The difference is that the outer surface area S4 of the side plate 322 is different.

[0126] Examples 43-44

[0127] A secondary battery is provided, with the same structure as in Embodiment 1. The area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 is 50.24 mm². 2 The opening area S2 of the first injection hole 311 is 7.07 mm. 2 All of them satisfy the range of 1.06≤S1 / S2≤10 and the range of 0.04≤S3 / S4≤3. The side plate 322 is inclined at an angle of 45 degrees toward the axis 3212 away from the second injection hole 3211 at the end near the body 321. The difference is that the flow area S3 of the outlet 3221 is 12mm. 2 The outer surface area S4 of the side plate 322 has different values.

[0128] Examples 45-46

[0129] A secondary battery is provided, with the same structure as in Embodiment 1. The area S1 of the orthogonal projection of the side of the baffle 323 facing the first injection hole 311 onto the body 321 is 50.24 mm². 2The opening area S2 of the first injection hole 311 is 7.07 mm. 2 All of them satisfy the range of 1.06≤S1 / S2≤10 and the range of 0.04≤S3 / S4≤3. The side plate 322 is inclined at an angle of 45 degrees toward the axis 3212 away from the second injection hole 3211 at the end near the body 321. The difference is that the flow area S3 of the outlet 3221 is 150mm. 2 The outer surface area S4 of the side plate 322 has different values.

[0130] Comparative Examples 5-6

[0131] A secondary battery is provided, with the same structure as in Embodiment 1, except that it does not satisfy the range of 1.06≤S1 / S2≤10, nor does it satisfy the range of 0.04≤S3 / S4≤3.

[0132] The specific data and test results of Examples 1, 32-46 and Comparative Examples 5-6 are shown in Table 3. The test process corresponding to the test results in Table 3 is the same as that in Table 1.

[0133] Table 3

[0134]

[0135]

[0136] As shown in Table 3, Examples 32-46 all meet the requirements of this application for preventing separator folding and improving electrolyte injection efficiency, thus improving battery safety while ensuring electrolyte injection efficiency. Examples 32-36, Examples 43-46, and Comparative Examples 5-6 show that the larger the flow area of ​​the outlet 3221, the higher the electrolyte injection efficiency. Examples 37-46 and Comparative Examples 5-6 show that the smaller the outer surface area of ​​the side plate 322, the higher the electrolyte injection efficiency. Therefore, by reasonably controlling the flow area of ​​the outlet 3221 and the outer surface area of ​​the side plate 322, electrolyte injection efficiency can be improved while preventing separator folding.

[0137] 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.

[0138] 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 in that, Having a first direction, including: The shell has a receiving cavity; Electrode assembly is disposed in the receiving cavity; A top cover assembly includes a top cover sheet and a lower insulating member. The top cover sheet is connected to the housing and covers the receiving cavity. The top cover sheet has a first liquid injection hole. The lower insulating member is disposed on the side of the top cover sheet facing the electrode assembly. The lower insulating element includes: The main body is connected to the top cover plate, and the main body is provided with a second injection hole that communicates with the first injection hole; 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. A baffle is connected to the side of the side plate away from the main body, and the baffle is disposed opposite to the second injection hole; the side plate has an outlet, and the outlet communicates with the second injection hole; along the first direction, the end of the side plate near the main body is inclined in a direction away from the axis of the second injection hole; The orthographic projection area of ​​the side of the baffle facing the first injection hole on the main 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.

2. The secondary battery according to claim 1, characterized in that, The orthographic projection area of ​​the side of the baffle facing the first injection hole on the main body and the opening area of ​​the first injection hole satisfy: 6≤S1 / S2≤9.

3. The secondary battery according to claim 1, characterized in that, The orthographic projection area of ​​the side of the baffle facing the first injection hole on the main body satisfies: 8.5 ≤ S1 ≤ 60; and / or, The opening area of ​​the first injection hole satisfies: 6≤S2≤8.

4. The secondary battery according to claim 1, characterized in that, Along the first direction, the side plate is inclined at an angle β° toward the axis away from the second injection hole at one end near the body, satisfying: 0 < β < 90.

5. The secondary battery according to claim 1, characterized in that, Along the first direction, the angle at which the end of the side plate near the body is inclined toward the axis away from the second injection hole satisfies: 30≤β≤60.

6. The secondary battery according to claim 1, characterized in that, The liquid outlet extends through the side plate in a direction that extends toward the body, and the side plate, the baffle, and the body together form the liquid outlet.

7. The secondary battery according to claim 1, characterized in that, The side plate has a plurality of liquid outlets, which are spaced apart circumferentially along the side plate, and each of the liquid outlets is connected to the second injection hole.

8. The secondary battery according to claim 7, characterized in that, The side plate includes multiple sub-plates, which are circumferentially spaced around the baffle. The sub-plates are connected to the main body, and 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.

9. The secondary battery according to claim 1, characterized in that, The flow area of ​​the liquid outlet is S3 mm. 2 The outer surface area of ​​the side plate is S4 mm. 2 The condition is satisfied that: 0.04≤S3 / S4≤3.

10. The secondary battery according to claim 1, characterized in that, The flow area of ​​the liquid outlet is S3 mm. 2 The outer surface area of ​​the side plate is S4 mm. 2 The condition is satisfied that: 0.3≤S3 / S4≤1.

11. The secondary battery according to claim 9, characterized in that, The flow area of ​​the outlet meets the following conditions: 12 ≤ S3 ≤ 150; and / or, The outer surface area of ​​the side plate satisfies: 50≤S4≤300.

12. The secondary battery according to claim 9, characterized in that, The flow area of ​​the outlet meets the following conditions: 40 ≤ S3 ≤ 130; and / or, The outer surface area of ​​the side plate satisfies: 150≤S4≤200.

13. The secondary battery according to claim 1, characterized in that, The side of the baffle facing the second injection hole is either a plane perpendicular to the axis, 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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