Secondary battery, battery pack, and electric device

Abstract

The invention discloses a secondary battery, a battery pack and a power utilization device, the secondary battery has a first direction and a second direction which are intersected, the secondary battery comprises a shell, an electrode assembly and a top cover assembly, the shell is provided with a containing cavity, the electrode assembly is arranged in the containing cavity, the top cover assembly comprises a top cover piece, a lower insulating part and an electrode terminal, the top cover piece is connected with the shell, and the lower insulating part is arranged in the top cover piece. The top cover plate is provided with a first liquid injection hole; the lower insulating part is connected to one side, facing the electrode assembly, of the top cover plate, and the electrode terminal penetrates through the top cover plate and the lower insulating part; the lower insulating part comprises a body and a turbulent flow part, and the body is provided with a second liquid injection hole communicated with the first liquid injection hole; the turbulent flow part is connected to the side, away from the top cover piece, of the body, the turbulent flow part and the electrode terminal are arranged at an interval, a liquid outlet is formed in the side, facing the electrode terminal, of the turbulent flow part, and the liquid outlet communicates with the second liquid injection hole; and along the second direction, the minimum distance between the liquid outlet and the electrode terminal is L1, the size of the top cover plate is L2, and L1 / L2 is greater than or equal to 0.004 and less than or equal to 0.5.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a secondary battery, a battery pack and an electrical device. Background Art

[0002] During the production of secondary batteries, electrolyte is injected into the shell. During the electrolyte injection process, the hydraulic pressure is relatively high, so the impact on the electrode assembly inside the secondary battery is relatively large, which can easily cause the diaphragm of the electrode assembly to fold, thereby causing a short circuit inside the secondary battery. Summary of the invention

[0003] Purpose of the invention: An embodiment of the present application provides a secondary battery, aiming to solve the problem that when the electrolyte is injected into the existing battery, the diaphragm is easily folded, thereby causing an internal short circuit in the battery; another purpose of the embodiment of the present application is to provide a battery pack; another purpose of the embodiment of the present application is to provide an electrical device.

[0004] Technical solution: A secondary battery according to an embodiment of the present application has a first direction and a second direction intersecting each other, including:

[0005] A housing having a receiving cavity;

[0006] An electrode assembly is disposed in the accommodating cavity;

[0007] A top cover assembly, comprising a top cover sheet, a lower insulating member and an electrode terminal, wherein the top cover sheet is connected to the shell and covers the accommodating cavity, and the top cover sheet has a first liquid injection hole; along the first direction, the lower insulating member is connected to a side of the top cover sheet facing the electrode assembly; the electrode terminal is penetrated through the top cover sheet and the lower insulating member, and the electrode terminal is conductively connected to the electrode assembly;

[0008] The lower insulating member comprises:

[0009] A body connected to the top cover sheet, the body having a second liquid injection hole communicating with the first liquid injection hole;

[0010] a spoiler connected to a side of the body away from the top cover sheet; along the first direction, at least part of the spoiler is spaced between the first liquid injection hole and the electrode assembly; the spoiler and the electrode terminal are spaced along the second direction, and a liquid outlet is provided on the side of the spoiler facing the electrode terminal, and the liquid outlet is communicated with the second liquid 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 sheet 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 sheet 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 size of the top cover sheet satisfies: 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 size of the top cover sheet satisfies: 100≤L2≤250.

[0019] In some embodiments,

[0020] The lower insulating member includes an explosion-proof valve boss, the explosion-proof valve boss is connected to a side of the body facing the electrode assembly, along the second direction, the explosion-proof valve boss is arranged on a side of the spoiler away from the electrode terminal, and the explosion-proof valve boss is spaced apart from the spoiler;

[0021] The flow spoiler has a plurality of liquid outlets, and at least one of the liquid outlets is arranged toward 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 sheet 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 liquid outlet facing the explosion-proof valve boss satisfies: 2≤A≤50; and / or,

[0026] The size of the top cover sheet satisfies: 100≤L2≤500.

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

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

[0029] The size of the top cover sheet satisfies: 100≤L2≤250.

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

[0031] In some embodiments, the spoiler comprises:

[0032] A side plate is arranged on a side of the body away from the top cover sheet and connected to the body, and the side plate is arranged on the outer peripheral side of the second liquid injection hole; the side plate has the liquid outlet, and the liquid outlet passes through the side plate along the first direction;

[0033] The baffle is connected to a side of the side plate away from the body, and is arranged between the first injection hole and the electrode assembly along the first direction; the baffle and the side plate enclose 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 on the body is S1 mm 2 , the opening area of ​​the first injection hole is S2 mm 2 , satisfying: 1.06≤S1 / S2≤10.

[0035] In some embodiments,

[0036] The area of ​​the orthographic projection of the side of the baffle plate facing the first liquid injection hole on the 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 with the second direction, the electrode assembly includes a tab, the tab is conductively connected to the electrode terminal, and the side plate and the tab are spaced apart along the third direction.

[0039] In some embodiments, the side plate includes a plurality of sub-plates, and the sub-plates are arranged in an arc shape around the outer peripheral side of the second liquid injection hole. The plurality of sub-plates are arranged at intervals, and the sub-plates are connected to the main body. One end of the sub-plate away from the main body is connected to the baffle plate, and two adjacent sub-plates, the baffle plate and the main body enclose a liquid outlet.

[0040] In some embodiments, the side surface of the baffle plate facing the second liquid injection hole is one of a flat surface, an arc surface protruding toward the second liquid injection hole, and a conical surface protruding toward the second liquid injection hole.

[0041] Accordingly, a battery pack described in an embodiment of the present application includes a secondary battery as described in any one of the aforementioned embodiments.

[0042] Accordingly, an electrical device described in an embodiment of the present application includes a secondary battery as described in any one of the aforementioned embodiments, or a battery pack as described in the aforementioned embodiments.

[0043] Beneficial effect: Compared with the prior art, a secondary battery in an embodiment of the present application has a first direction and a second direction intersecting each other, and includes a shell, an electrode assembly and a top cover assembly, the shell has a accommodating cavity, the electrode assembly is arranged in the accommodating cavity, the top cover assembly includes a top cover sheet, a lower insulating member and an electrode terminal, the top cover sheet is connected to the shell and covers the accommodating 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 terminal is penetrated through the top cover sheet and the lower insulating member, and the electrode terminal is conductively connected to the electrode assembly. The lower insulating member includes a main body and a spoiler, the main body is connected to the top cover sheet, and the main body has a second liquid injection hole connected to the first liquid injection hole; the spoiler is connected to a side of the main body away from the top cover sheet, and along the first direction, at least part of the spoiler is spaced between the first liquid injection hole and the electrode assembly; the spoiler and the electrode terminal are spaced along the second direction, and a liquid outlet is provided on the side of the spoiler facing the electrode terminal, and the liquid outlet is connected to 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 sheet is L2 mm, satisfying: 0.004≤L1 / L2≤0.5. The present application achieves a change in the electrolyte injection direction by providing a spoiler and configuring a liquid outlet, with the liquid outlet facing the electrode terminal, thereby reducing 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 thus causing an internal short circuit in the secondary battery; in addition, by setting a proportional relationship between the distance between the liquid outlet and the electrode terminal and the size of the top cover sheet, it is ensured that the liquid outlet is not blocked as much as possible, which can reduce the blocking effect of the electrode terminal on the electrolyte, thereby achieving a good electrolyte injection efficiency.

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

[0045] Compared with the prior art, an electric device in an embodiment of the present application includes a secondary battery as in any one of the aforementioned embodiments, or a battery pack as in the aforementioned embodiments. It is understood that the electric device in an embodiment of the present application includes all the technical features and technical effects of the aforementioned secondary battery or battery pack, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0047] Figure 1 is a schematic diagram of the overall structure of a secondary battery in an embodiment of the present application;

[0048] Figure 2 is an exploded diagram of a secondary battery according to an embodiment of the present application;

[0049] Figure 3 is a cross-sectional view of a secondary battery according to an embodiment of the present application along a direction perpendicular to the second direction;

[0050] Figure 4 yes Figure 3 A magnified view of part A;

[0051] Figure 5 is a structural schematic diagram of a top cover assembly of a secondary battery in an embodiment of the present application;

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

[0053] Figure 7 yes Figure 6 A magnified view of part B;

[0054] Figure 8 It is a bottom view of a secondary battery according to an embodiment of the present application along a first direction perpendicular to the first direction.

[0055] Figure numerals: 1, shell; 11, accommodating cavity; 2, electrode assembly; 21, pole ear; 22, winding core; 3, top cover assembly; 31, top cover sheet; 311, first liquid injection hole; 32, lower insulating member; 321, main body; 3211, second liquid injection hole; 322, spoiler; 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 DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0057] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined. In the description of this application, "vertical" means completely vertical at 90° or almost completely vertical, for example, an angle within the range of 80° to 100° is considered vertical. Similarly, "parallel" means completely parallel or almost completely parallel, for example, an angle within 10° of completely parallel is considered parallel.

[0058] It should also be noted that in the drawings of the present application, the arrow marked Z indicates the first direction Z, the arrow marked X indicates the second direction X, and the arrow marked Y indicates the third direction Y. The first direction Z, the second direction X, and the third direction Y are introduced to facilitate the description of the structural position relationship of the secondary battery, and thus facilitate the understanding of its structure. In the embodiment of the present 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; and the first direction Z, the second direction X, and the third direction Z intersect with each other, and further, 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 process of secondary batteries, it is usually necessary to inject electrolyte into the secondary battery through the injection hole set in the top cover assembly of the secondary battery. And the higher the injection efficiency of the electrolyte, the higher the production efficiency of the battery. However, in the current battery production process, in order to improve the injection efficiency, the pressure of electrolyte injection is usually high, which is easy to impact the diaphragm of the electrode assembly, causing the diaphragm to fold, and then cause a short circuit inside the secondary battery; and if the pressure of the injected electrolyte is reduced, the efficiency of electrolyte injection will be reduced.

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

[0061] Please refer to Figure 1-Figure 8 The embodiment of the present application provides a secondary battery having a first direction Z and a second direction X intersecting each other, comprising a shell 1, an electrode assembly 2 and a top cover assembly 3, wherein the shell 1 has a receiving cavity 11, the electrode assembly 2 is arranged in the receiving cavity 11, the top cover assembly 3 comprises a top cover sheet 31, a lower insulating member 32 and an electrode terminal 33, the top cover sheet 31 is connected to the shell 1 and covers the receiving cavity 11, and the top cover sheet 31 has a first liquid injection hole 311; along the first direction Z, the lower insulating member 32 is connected to a side of the top cover sheet 31 facing the electrode assembly 2; the electrode terminal 33 is penetrated through the top cover sheet 31 and the lower insulating member 32, and the electrode terminal 33 is conductively connected to the electrode assembly 2; the lower insulating member 32 comprises the present The body 321 and the spoiler 322, the body 321 is connected to the top cover sheet 31, the body 321 has a second liquid injection hole 3211 connected to the first liquid injection hole 311; the spoiler 322 is connected to the side of the body 321 away from the top cover sheet 31, along the first direction Z, at least part of the spoiler 322 is arranged between the first liquid injection hole 311 and the electrode assembly 2; the spoiler 322 and the electrode terminal 33 are arranged at intervals along the second direction X, and the side of the spoiler 322 facing the electrode terminal 33 is provided with a liquid outlet 3221, and the liquid outlet 3221 is connected to the second liquid injection hole 3211; along the second direction X, the minimum distance between the liquid outlet 3221 and the electrode terminal 33 is L1 mm, the size of the top cover sheet 31 is L2 mm, and it satisfies: 0.004≤L1 / L2≤0.5.

[0062] In the embodiment of the present application, a spoiler 322 is provided and a liquid outlet 3221 is configured, with the liquid outlet 3221 facing the electrode terminal 33, so that the electrolyte injection direction is changed, and the direct impact of the electrolyte on the electrode assembly 2 is reduced, thereby reducing the risk of the electrolyte impacting the diaphragm, causing the diaphragm to fold and thus causing an internal short circuit in the secondary battery; in addition, by setting the distance between the liquid outlet 3221 and the electrode terminal 33 in proportion to the size of the top cover sheet 31, it is ensured that the liquid outlet 3221 is not blocked, thereby achieving better electrolyte discharge efficiency.

[0063] Specifically, in the embodiment of the present application, the spoiler 322 is arranged on the side of the main body 321 away from the top cover sheet 31, and is arranged at intervals between the first injection hole 311 and the electrode assembly 2. At this time, the spoiler 322 can be used to make the electrolyte injected from the first injection hole 311 preferentially impact the spoiler 322, and the spoiler 322 is used to directly interfere with the flow direction of the electrolyte, so that the electrolyte changes from flowing toward the electrode assembly 2 to flowing toward the electrode terminal 33 through the liquid outlet 3221. At this time, the possibility of the electrolyte directly impacting the electrode assembly 2 and causing the diaphragm to fold can be reduced, thereby effectively reducing the possibility of internal short circuit in the secondary battery, thereby improving the safety of the secondary battery.

[0064] It should be noted that in the embodiment of the present application, the liquid outlet 3221 is arranged toward the electrode terminal 33, that is, the liquid outlet 3221 is arranged opposite to the electrode terminal 33. At this time, the minimum distance between the liquid outlet 3221 and the electrode terminal 33 is the distance between the point of the electrode terminal 33 closest to the liquid outlet 3221 and the plane where the liquid outlet 3221 is located. Since the electrode liquid flowing out of the liquid outlet 3221 will flow toward the electrode terminal 33, contact the electrode terminal 33, and be blocked by the electrode terminal 33, therefore, controlling the minimum distance between the electrode terminal 33 and the liquid outlet 3221 within a reasonable range can reduce the blocking effect of the electrode terminal 33 on the electrolyte, and at this time can ensure that the battery cell has a high injection efficiency. It should be noted that, please further participate Figure 7 and Figure 8 , when the distance between the electrode terminal 33 and the liquid outlet 3221 is far, it will not have a negative impact on the electrolyte injection efficiency. If the distance between the two electrode terminals 33 and the liquid outlet 3221 is close, the electrolyte rushing out of the liquid outlet 3221 directly impacts the electrode terminal 33, and the electrode terminal 33 causes a certain obstruction to the electrolyte. At this time, the electrode terminal 33 may also affect the liquid outlet rate of the liquid outlet 3221, and it is easy to cause an adverse effect on the voltage of the electrode terminal 33. Therefore, the embodiment of the present application is set along the second direction X, the minimum distance between the liquid outlet 3221 and the electrode terminal 33 is L1 mm, and the size of the top cover sheet 31 is L2 mm, which satisfies: 0.004≤L1 / L2≤0.5. Within this range, there is a more reasonable distance between the liquid outlet 3221 and the electrode terminal 33. At this time, the electrode terminal 33 will not block the electrolyte, and the secondary battery can be guaranteed to have a good injection efficiency.

[0065] It should also be noted that in the embodiments of the present 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 , 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, 0.5, or the range between any two values. When the minimum distance L1 between the liquid outlet 3221 and the electrode terminal 33 and the size L2 of the top cover sheet 31 meet the range of 0.004≤L1 / L2≤0.5, the minimum distance between the liquid outlet 3221 and the electrode terminal 33 and the size of the top cover sheet 31 can be within a reasonable range. At this time, it can not only reduce the possibility of the electrolyte impacting the electrode assembly 2 and causing the diaphragm of the electrode assembly 2 to fold, but also ensure that the electrolyte has a faster injection efficiency. The larger the value of L1 / L2, the smaller the influence of the corresponding electrode terminal 33 on the efficiency of electrolyte injection. If L1 / L2<0.004, the distance between the liquid outlet 3221 and the electrode terminal 33 is relatively close relative to the overall size of the top cover assembly 3, and the electrode terminal 33 may cause a certain obstruction to the electrolyte, which may have a certain impact on the injection efficiency of the electrolyte. In addition, the distance between the liquid outlet 3221 and the electrode terminal 33 is small, which may cause poor voltage of the electrode terminal 33. If L1 / L2>0.5, the distance between the liquid outlet 3221 and the electrode terminal 33 is relatively large compared to the overall size of the top cover assembly 3, which may cause the top cover assembly 3 to fail to be produced. The liquid injection hole and the electrode terminal 33 cannot be reasonably arranged within the length range of the top cover sheet 31, resulting in the embarrassing situation that the top cover assembly 3 cannot be produced normally. Therefore, controlling the distance between the electrode terminal 33 and the liquid outlet 3221 to be within a reasonable range as much as possible can not only ensure that the electrolyte has a good injection efficiency, but also avoid the diaphragm of the electrode assembly 2 from folding, thereby improving the qualified rate 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 sheet 31 further satisfy: 0.04≤L1 / L2≤0.39.

[0067] In some embodiments, some common dimension measurement methods can be selected to measure and obtain L1 and L2, for example, they can be directly measured using measuring tools such as a vernier caliper or a micrometer.

[0068] In some embodiments, further see 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 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, or the range between any two values. If L1 is too large, for the square shell battery in the embodiment of the present application, there will be a problem that the two electrode terminals 33 cannot be reasonably arranged on the top cover sheet 31, which will cause the top cover assembly 3 to fail to be produced normally. When L1 is too small, the electrode terminal 33 will block the electrolyte flowing out of the liquid outlet 3221, resulting in a decrease in the electrolyte flow rate, thereby affecting the injection efficiency of the secondary battery. In addition, it is also easy to interfere with the voltage of the electrode terminal 33, resulting in poor voltage of the electrode terminal 33. It should also be noted that when L1 is too small, the electrolyte may still have a faster speed after being blocked by the electrode terminal 33 and changing direction, and impact the electrode assembly 2. At this time, it may also cause the diaphragm of the electrode assembly 2 to fold, thereby causing an internal short circuit in the secondary battery. Furthermore, the minimum distance between the liquid outlet 3221 and the electrode terminal 33 satisfies: 3≤L1≤40.

[0069] In some embodiments, along the second direction X, the size of the top cover sheet 31 satisfies: 100≤L2≤500. For example, the value range of L2 can be any one of 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, 500, or the range between any two values. If the size L2 of the top cover sheet 31 is too large, it may be difficult to produce or the corresponding lower insulating member 32 may be easily deformed. If the size of the top cover sheet 31 is too small, it is not conducive to the reasonable layout of the spoiler 322 and the electrode terminal 33, and the battery capacity is also small. Further, in some embodiments, the size of the top cover sheet 31 satisfies: 100≤L2≤250.

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

[0071] In the embodiment of the present application, the injection efficiency can be further improved by providing multiple liquid outlets 3221. Preferably, two liquid outlets 3221 are provided, one of which is provided toward the electrode terminal 33, and the other of which is provided toward the explosion-proof valve boss 323. In this case, the electrolyte flowing out of the liquid outlet 3221 can be prevented from directly impacting the pole ear 21, thereby affecting the welding effect of the pole ear 21. At the same time, it can also prevent the pole ear 21 from overlapping and short-circuiting with the top cover sheet 31 through the liquid outlet 3221.

[0072] It should be noted that in the embodiment of the present application, the top cover assembly 3 includes an explosion-proof valve 34, which is embedded in the top cover sheet 31 and is used to open and release pressure when the internal pressure is too high due to thermal runaway of the battery cell. The explosion-proof valve boss 323 is arranged 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, so as to provide a space for gas flow around the explosion-proof valve 34, so as to facilitate the direct action of the thermal runaway gas on the explosion-proof valve 34. Among them, the explosion-proof valve boss 323 also has a through hole 3231, which penetrates the explosion-proof valve 34 boss 323 along the first direction Z and is connected to the groove 324, so as to facilitate the flow of thermal runaway gas. At the same time, the through hole 3231 can also provide a buffer path for the flow of electrolyte, which is more convenient for electrolyte injection.

[0073] Please refer to 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 the embodiment of the present application, by setting the minimum distance between the explosion-proof valve boss 323 and the liquid outlet 3221 facing the explosion-proof valve boss 323 and the size of the top cover sheet 31 to meet the range of 0.004≤A / L2≤0.5, it can be further achieved that the liquid outlet 3221 arranged opposite to the explosion-proof valve boss 323 can smoothly discharge the electrolyte, thereby further improving the electrolyte injection efficiency. At this time, the liquid outlet 3221 opposite to the electrode terminal 33 and the liquid outlet 3221 opposite to the explosion-proof valve boss 323 can quickly discharge the electrolyte, so that the spoiler 322 can have a higher liquid discharge efficiency on the basis of blocking the electrolyte and preventing the diaphragm from bending.

[0075] It is understood that 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, Any value among 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, 0.5, or the range between any two values. When the minimum distance between the liquid outlet 3221 and the explosion-proof valve boss 323 and the size of the top cover sheet 31 meet the range of 0.004≤A / L2≤0.5, the minimum distance between the liquid outlet 3221 and the explosion-proof valve boss 323 and the size of the top cover sheet 31 can be within a reasonable range, which can not only reduce the possibility of the electrolyte impacting the electrode assembly 2 and causing the diaphragm of the electrode assembly 2 to be folded, but also ensure that the electrolyte has a faster injection efficiency, and the larger the value of A / L2, the smaller the influence of the corresponding explosion-proof valve boss 323 on the outflow efficiency of the electrolyte flowing out of the liquid outlet 3221 opposite to it. If A / L2<0.004, at this time, the distance between the liquid outlet 3221 and the explosion-proof valve boss 323 is relatively close relative to the overall size of the top cover sheet 31, and the explosion-proof valve boss 323 may cause a certain obstruction to the electrolyte flowing out of the liquid outlet 3221, which may have a certain impact on the injection efficiency of the electrolyte. If A / L2>0.5, the distance between the liquid outlet 3221 and the explosion-proof valve boss 323 is relatively large compared with the overall size of the top cover sheet 31. Although it will not affect the injection efficiency of the electrolyte, it may cause the top cover assembly 3 to be unable to be produced. There will be insufficient space to set the injection hole and the explosion-proof valve boss 323, resulting in the embarrassing situation that the top cover assembly 3 cannot be produced normally. Therefore, the distance between the explosion-proof valve boss 323 and the liquid outlet 3221 is controlled as much as possible within a reasonable range, which can not only ensure that the electrolyte has a good injection efficiency, but also avoid the diaphragm of the electrode assembly 2 from folding, thereby improving the qualified 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 liquid outlet 3221 facing the explosion-proof valve boss 323, and the size of the top cover sheet 31 meet: 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 liquid outlet 3221 facing it satisfies: 2≤A≤50. For example, the value range of A can be any one 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, or the range between any two values. If A is too large, for the square shell battery of the embodiment of the present application, there will be a problem that the two electrode terminals 33, the explosion-proof valve and the spoiler 322 cannot be reasonably arranged on the lower insulating part 32, which will cause the top cover assembly 3 to fail to be produced normally. When A is too small, the explosion-proof valve boss 323 will block the electrolyte flowing out of the liquid outlet 3221, resulting in a decrease in the electrolyte flow rate, thereby affecting the injection efficiency of the secondary battery. It should also be noted that when A is too small, the electrolyte may still have a faster speed after being blocked by the explosion-proof valve boss 323 and changing direction, and impacting the electrode assembly 2. At this time, it may also cause the diaphragm of the electrode assembly 2 to fold, thereby causing an internal short circuit in the secondary battery. Furthermore, the minimum distance between the liquid outlet 3221 and the explosion-proof valve boss 323 satisfies: 3≤A≤40.

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

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

[0079] Please refer to Figure 3 , Figure 4 and Figure 7 In some embodiments, the spoiler 322 has a cavity 3222 , and the cavity 3222 is communicated with the second liquid injection hole 3211 and the liquid outlet 3221 , respectively.

[0080] In the embodiment of the present application, a cavity 3222 is provided in the spoiler 322, and the cavity 3222 is used to accommodate the electrolyte injected from the injection hole, and the electrolyte is buffered and redirected so that the electrolyte flows out from the liquid outlet 3221. At this time, the electrolyte can be prevented from causing impact and damage to the electrode assembly 2 inside the secondary battery. For example, by changing the direction of the electrolyte, the diaphragm can be effectively prevented from folding.

[0081] Please refer to Figure 3-Figure 8 In some embodiments, the spoiler 322 includes a side plate 3223 and a baffle 3224, the side plate 3223 is arranged on a side of the main body 321 away from the top cover sheet 31 and is connected to the main body 321, and the side plate 3223 is arranged on the outer peripheral side of the second liquid 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 main body 321, and along the first direction Z, the baffle 3224 is spaced between the first liquid injection hole 311 and the electrode assembly 2; the baffle 3224 and the side plate 3223 surround the cavity 3222.

[0082] In the embodiment of the present application, the spoiler 322 is formed by setting the side plate 3223 and the baffle 3224. At this time, the baffle 3224 is arranged relative to the first injection hole 311 and the second injection hole 3211, which can play a good blocking spoiler effect. The side plate 3223 can further cause spoiler and convergence to the electrolyte, and realize the directional injection of the electrolyte. At the same time, the side plate 3223 is used to connect the baffle 3224 with the body 321 to ensure the stability of the structure. At this time, the side plate 3223 and the baffle 3224 are used to enclose a cavity 3222, which can be used to buffer the electrolyte. The liquid outlet 3221 is connected to the cavity 3222 to ensure the injection effect.

[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 , satisfying: 1.06≤S1 / S2≤10.

[0084] In the embodiment of the present application, the ratio of the area of ​​the projection of the side of the baffle 3224 facing the first injection hole 311 on the main body 321 to 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 projection of the side of the baffle 3224 facing the first injection hole 311 on the main body 321 is greater than or equal to the area of ​​the first injection hole 311. In this way, it can at least ensure that the baffle 3224 can effectively block the electrolyte injected into the first injection hole 311, thereby avoiding the folding of the diaphragm caused by the direct impact of the electrolyte on the electrode assembly 2.

[0085] In the embodiment of the present application, the numerical range of S1 / S2 can be any one of 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, 10 or the range between any two values. The larger the numerical value of S1 / S2, the larger the area of ​​the corresponding baffle 3224, the larger the blocking area for the electrolyte, and the larger the protection area for the electrode assembly 2, and the smaller the possibility of the diaphragm of the corresponding electrode assembly 2 being folded. If the value of S1 / S2 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 quickly and smoothly infiltrating the inside of the electrode assembly 2. If the value of S1 / S2 is too small, the baffle 3224 may not be able to completely cover the first injection hole 311, which may cause the risk of the diaphragm folding. Further, in some embodiments, the area of ​​the positive projection of the side of the baffle 3224 facing the first injection hole 311 on the body 321 is S1 mm 2 , the opening area of ​​the first injection hole 311311 is S2 mm 2 , satisfying: 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 on the main body 321 satisfies: 8.5≤S1≤60.

[0087] In the embodiment of the present application, the value of S1 can be any one of 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, 50, or a range between any two values. As S1 increases, the corresponding baffle 3224 has a better blocking effect on the electrolyte, and the wall diaphragm can be folded as much as possible. However, if the baffle 3224 is too large, it will 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 embodiment of the present 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 a range between any two values.

[0090] It should be noted that the area of ​​the orthographic projection of the baffle 3224 on the body 321 facing the first injection hole 311 is S1 mm. 2 , the opening area of ​​the first injection hole 311311 is S2 mm 2 If it is an area of ​​a regular shape such as a rectangle, square, circle, trapezoid, or sector, the corresponding size can be measured and calculated using the area measurement formula of the corresponding shape. If it is an area of ​​an irregular shape, the coating method can be used for measurement. In other words, a coating with uniform mass is covered on the first injection hole 311 and attached to the outer peripheral side of the first injection hole 311311, the coating corresponding to the opening of the first injection hole 311 is removed, and the mass of the coating is determined. The quotient of the mass of the removed coating and the mass per unit area of ​​the coating that has been determined in advance is determined as the area of ​​the first injection hole 311 being measured. Similarly, the film is attached to the main body 321, and the side of the baffle 3224 facing the first injection hole 311 is projected onto the film. The portion of the film corresponding to the orthographic projection is removed, and the mass of the film is determined. The quotient of the mass of the film and the mass per unit area of ​​the film determined in advance is determined as the orthographic projection area of ​​the baffle 3224 on the main body 321 facing the first injection hole 311.

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

[0092] In the embodiment of the present application, the side plate 3223 and the pole ear 21 are spaced apart along the third direction Y, and can further be relatively spaced apart. At this time, on the one hand, it can avoid that the pole ear 21 partially blocks or interferes with the liquid outlet 3221. At the same time, the side plate 3223 can isolate the pole ear 21 from the cavity 3222, thereby blocking the pole ear 21 and further preventing the pole ear 21 from overlapping and short-circuiting with the top cover sheet 31.

[0093] Please refer to Figure 4-Figure 7 In some embodiments, along the first direction Z, the liquid outlet 3221 passes through the side plate 3223 .

[0094] In the embodiment of the present application, the liquid outlet 3221 is arranged to pass through the side plate 3223 along the first direction Z. At this time, on the one hand, it can be ensured that the liquid outlet 3221 has a larger flow area. On the other hand, it can avoid the accumulation of electrode liquid in the cavity 3222 surrounded by the side plate 3223 and the baffle 3224, which is conducive to the rapid outflow of electrolyte from the cavity 3222.

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

[0096] In the embodiment of the present application, the side plate 3223 is arranged to be bent in an arc shape around the outer peripheral side of the second liquid injection hole 3211. At this time, the part of the side plate 3223 closest to the pole ear 21 can be relatively far away from the liquid outlet 3221 (relative to the side plate 3223 being a straight plate). At this time, even if the pole ear 21 is relatively long or wide, the side plate 3223 can effectively block the pole ear 21 to prevent the pole ear 21 from reaching the liquid outlet 3221, and overlap with the top cover sheet 31 at the liquid 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, and the plurality of sub-plates 32231 are circumferentially spaced around the second liquid injection hole 3211, the sub-plates 32231 are connected to the main body 321, and one end of the sub-plate 32231 away from the main body 321 is connected to the baffle 3224, and two adjacent sub-plates 32231, the baffle 3224 and the main body 321 enclose a liquid outlet 3221.

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

[0099] In the embodiment of the present application, the side of the baffle 3224 facing the second injection hole 3211 can be a plane, and further, the baffle 3224 is a flat plate structure as a whole, which can ensure that the baffle 3224 occupies as little space as possible between the winding core 22 and the top cover sheet 31, and provide a sufficient size for the cavity 3222 to buffer the electrolyte. At the same time, the flat plate can prevent the electrolyte from accumulating in the cavity 3222.

[0100] In the embodiment of the present application, the side surface of the baffle 3224 facing the second liquid injection hole 3211 can be a circular arc surface protruding toward the second liquid injection hole 3211. At this time, the electrolyte can flow along the circular arc surface in a direction away from the second liquid injection hole 3211, which can directly redirect the electrolyte, facilitate the rapid outflow of the electrolyte from the liquid outlet 3221, and avoid the accumulation of electrolyte in the cavity 3222.

[0101] In the embodiment of the present application, the side surface of the baffle 3224 facing the second injection hole 3211 can be a conical surface protruding toward the second injection hole 3211. At this time, the apex of the conical surface is opposite to the second injection hole 3211. At this time, the obstruction of the conical surface to the electrolyte can be further reduced, so that the electrolyte can be directly redirected along the conical surface, thereby improving the injection efficiency of the outlet 3221 and avoiding the accumulation of electrolyte on the baffle 3224 and in the cavity 3222.

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

[0103] An embodiment of the present application further provides an electrical device, comprising a secondary battery as in any one of the aforementioned embodiments, or a battery pack as in the aforementioned embodiments.

[0104] It can be understood that the electrical device of the embodiment of the present application includes all the technical features and technical 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 may be application devices such as vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and electric tools. Vehicles may be new energy vehicles, which may be pure electric vehicles, hybrid electric vehicles or extended-range vehicles, etc.; spacecraft include airplanes, rockets, space shuttles and spacecrafts, etc.; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc. The embodiments of this application do not impose any special restrictions on the above-mentioned electrical devices.

[0106] The secondary battery of the present application is described in detail below with reference to specific embodiments.

[0107] Example 1

[0108] A secondary battery is provided, comprising: Figure 7 and Figure 8 The spoiler 322, electrode terminal 33 and explosion-proof valve boss 323 are shown in FIG. 1 . The minimum distance between the liquid outlet 3221 of the spoiler 322 facing the explosion-proof valve boss 323 and the explosion-proof valve boss 323 is 39 mm. The overall structure of the secondary battery is as shown in FIG. Figure 1 and Figure 2 As shown, the minimum distance L1 between the liquid outlet 3221 of the spoiler 322 facing the electrode terminal 33 and the electrode terminal 33 and the size L2 of the top cover sheet 31 satisfy: 0.004≤L1 / L2≤0.5. For specific structural dimension parameters, see Table 1.

[0109] Embodiment 2-7

[0110] A secondary battery is provided, the specific structure of which is the same as that of the first embodiment, except that the minimum distance L1 between the liquid outlet 3221 of the spoiler 322 facing the electrode terminal 33 and the electrode terminal 33 has a different value.

[0111] Embodiment 8-14

[0112] A secondary battery is provided, the specific structure of which is the same as that of the first embodiment, except that the size L2 of the top cover sheet 31 has a different value.

[0113] Examples 15-16

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

[0115] Examples 17-18

[0116] A secondary battery is provided, the specific structure of which is the same as that of Embodiment 1, except that the minimum distance L1 between the liquid outlet 3221 of the spoiler 322 facing the electrode terminal 33 and the electrode terminal 33 is 50 mm, and the size L2 of the top cover sheet 31 has a different value.

[0117] Examples 19-24

[0118] A secondary battery is provided, the specific structure of which is the same as that of Example 1, except that the minimum distance between the liquid outlet 3221 of the spoiler 322 facing the electrode terminal 33 and the electrode terminal 33 is 39 mm, the size of the top cover sheet 31 is 150 mm, and the value of the minimum distance between the liquid outlet 3221 of the spoiler 322 facing the explosion-proof valve boss 323 and the explosion-proof valve boss 323 is different.

[0119] Embodiment 25

[0120] A secondary battery is provided, the specific structure of which is the same as that of embodiment 1, except that the size of the top cover sheet 31 is 500 mm, and the minimum distance between the liquid outlet 3221 of the spoiler 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, the specific structure of which is the same as that of 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, and the opening area of ​​the first injection hole 311 is 7.07mm 2 , the difference is that the area of ​​the positive projection of the side of the baffle 3224 facing the first liquid injection hole 311 on the main body 321 has a different value.

[0123] Examples 34-38

[0124] A secondary battery is provided, the specific structure of which is the same as that of Embodiment 1, and both satisfy the ranges of 0.004≤L1 / L2≤0.5 and 0.004≤A / L2≤0.5, and the area of ​​the orthographic projection of the side of the baffle 3224 facing the first liquid injection hole 311 on the body 321 is 50.24mm 2 , the difference is that the value of the opening area of ​​the first injection hole 311 is different.

[0125] Examples 39-40

[0126] A secondary battery is provided, the specific structure of which is the same as that of Embodiment 1, and both satisfy the ranges of 0.004≤L1 / L2≤0.5 and 0.004≤A / L2≤0.5, and the area of ​​the orthographic projection of the side of the baffle 3224 facing the first injection hole 311 on the body 321 is 8.5 mm 2 , the opening area of ​​the first injection hole 311 has different values.

[0127] Examples 41-42

[0128] A secondary battery is provided, the specific structure of which is the same as that of embodiment 1, and both satisfy the range of 0.004≤L1 / L2≤0.5 and 0.004≤A / L2≤0.5, and the area of ​​the positive projection of the side of the baffle 3224 facing the first injection hole 311 on the body 321 is 60mm 2 , the opening area of ​​the first injection hole 311 has different values.

[0129] Comparative Example 1-2

[0130] The specific structure is the same as that of 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 test methods are as follows:

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

[0133] Electrolyte injection efficiency: A secondary battery according to the embodiment of the present application is placed in a liquid injection machine; the liquid injection machine first evacuates the interior of the secondary battery to make the air pressure inside the secondary battery below -90Kpa. At this time, the electrolyte has been stored in the liquid injection cup. Since the interior of the secondary battery is in a negative pressure state, the electrolyte flows into the interior of the secondary battery; then the liquid injection machine performs alternating positive and negative pressure cycles on the secondary battery (positive pressure 180Kpa (30-60S) negative pressure -60Kpa (3-15S), cycle 4-12 times) so that the electrolyte can be fully injected into the interior of the secondary battery. The time required for the entire liquid injection process is t1 min. The same liquid injection operation is performed on a secondary battery of the same specification without a spoiler 322, and the time required for the entire liquid injection process is recorded as t2 min. If t1 / t2≥98%, it means that the liquid injection efficiency meets the requirements.

[0134] Table 1

[0135]

[0136]

[0137]

[0138]

[0139] As can be seen from Table 1, the secondary batteries of Examples 1-18 all meet the range of 0.004≤L1 / L2≤0.5, meeting the requirements that the secondary batteries can prevent the diaphragm of the electrode assembly from folding during liquid injection and have good liquid injection efficiency. By comparing Examples 1-18 with Comparative Examples 1-2, it can be seen that when L1 is too large or L2 is too small, the top cover assembly 3 cannot be produced normally; when L1 is too small or L2 is too large, the electrode terminal 33 will block the liquid outlet 3221 due to the small distance between the liquid outlet 3221 and the electrode terminal 33, which will reduce the liquid injection efficiency and cause the electrolyte to flow out from between the two at a high speed, which is easy to cause the diaphragm to fold; in addition, when the spacing is reasonable, but the size L2 of the top cover sheet 31 is small, the top cover assembly 3 cannot be produced normally. It can be seen from Examples 8-14 and Examples 19-25 that the secondary battery satisfies 0.004≤L1 / L2≤0.5 while also satisfying 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 injection efficiency.

[0140] As can be seen from Table 1, the secondary batteries of Examples 26-42 further satisfy 1.06≤S1 / S2≤10 while satisfying the range of 0.004≤L1 / L2≤0.5 and 0.004≤A / L2≤0.5. Under this range, the injection efficiency of the secondary battery can be ensured while preventing the diaphragm from folding. Among them, as the value of S1 / S2 increases, the injection efficiency is relatively good at this time, but the corresponding area of ​​S1 is relatively small, and the shielding effect of the first injection hole will be reduced at this time, and there may be a risk of diaphragm folding. If the S1 / S2 ratio is too large, although the possibility of diaphragm folding is small, the corresponding blocking area is too large, which will affect the injection efficiency of the electrolyte of the secondary battery.

[0141] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0142] The above is a detailed introduction to a secondary battery, a battery pack and an electrical device provided in the embodiments of the present application, and specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A secondary battery, characterized in that: Having an intersecting first direction and a second direction, comprising: A housing having a receiving cavity; An electrode assembly is disposed in the accommodating cavity; A top cover assembly, comprising a top cover sheet, a lower insulating member and an electrode terminal, wherein the top cover sheet is connected to the shell and covers the accommodating cavity, and the top cover sheet has a first liquid injection hole; along the first direction, the lower insulating member is connected to a side of the top cover sheet facing the electrode assembly; the electrode terminal is penetrated through the top cover sheet and the lower insulating member, and the electrode terminal is conductively connected to the electrode assembly; The lower insulating member comprises: A body connected to the top cover sheet, the body having a second liquid injection hole communicating with the first liquid injection hole; a spoiler connected to a side of the body away from the top cover sheet; along the first direction, at least part of the spoiler is spaced between the first liquid injection hole and the electrode assembly; the spoiler and the electrode terminal are spaced along the second direction, and a liquid outlet is provided on a side of the spoiler facing the electrode terminal, and the liquid outlet is communicated 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 sheet is L2 mm, satisfying: 0.004≤L1 / L2≤0.

5.

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

39.

3. The secondary battery according to claim 1, characterized in that: Along the second direction, the minimum distance between the liquid outlet and the electrode terminal satisfies: 2≤L1≤50; and / or, The size of the top cover sheet satisfies: 100≤L2≤500.

4. The secondary battery according to claim 1, characterized in that: Along the second direction, The minimum distance between the liquid outlet and the electrode terminal satisfies: 5≤L1≤39; and / or, The size of the top cover sheet satisfies: 100≤L2≤250.

5. The secondary battery according to claim 1, characterized in that: The lower insulating member includes an explosion-proof valve boss, which is connected to a side of the body facing the electrode assembly; along the second direction, the explosion-proof valve boss is arranged on a side of the spoiler away from the electrode terminal, and the explosion-proof valve boss is spaced apart from the spoiler; The flow spoiler has a plurality of liquid outlets, and at least one of the liquid outlets is arranged toward the explosion-proof valve boss.

6. The secondary battery according to claim 5, 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 sheet satisfy: 0.04≤A / L2≤0.

39.

7. The secondary battery according to claim 6, 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 satisfies: 2≤A≤50; and / or, The size of the top cover sheet satisfies: 100≤L2≤500.

8. The secondary battery according to claim 7, characterized in that: Along the second direction, The minimum distance between the explosion-proof valve boss and the liquid outlet facing it satisfies: 5≤A≤39; and / or, The size of the top cover sheet satisfies: 100≤L2≤250.

9. The secondary battery according to claim 1, characterized in that: The spoiler has a cavity, and the cavity is communicated with the second liquid injection hole and the liquid outlet respectively.

10. The secondary battery according to claim 9, characterized in that: The spoiler comprises: A side plate is arranged on a side of the body away from the top cover sheet and connected to the body, and the side plate is arranged on the outer peripheral side of the second liquid injection hole; the side plate has the liquid outlet, and the liquid outlet passes through the side plate along the first direction; The baffle is connected to a side of the side plate away from the body, and is arranged between the first injection hole and the electrode assembly along the first direction; the baffle and the side plate enclose the cavity.

11. The secondary battery according to claim 10, characterized in that: Along the first direction, the area of ​​the orthographic projection of the side of the baffle plate facing the first injection hole on the body is S1 mm 2 , the opening area of ​​the first injection hole is S2 mm 2 , satisfying: 1.06≤S1 / S2≤10.

12. The secondary battery according to claim 11, characterized in that: The area of ​​the orthographic projection of the side of the baffle plate facing the first liquid injection hole on the body satisfies: 8.5≤S1≤60; and / or, The opening area of ​​the first injection hole satisfies: 6≤S2≤8.

13. The secondary battery according to claim 10, characterized in that: The secondary battery has a third direction intersecting with the second direction. The electrode assembly includes a tab, the tab is conductively connected to the electrode terminal, and the side plate and the tab are spaced apart along the third direction.

14. The secondary battery according to claim 10, characterized in that: The side plate includes a plurality of sub-plates, and the sub-plates are arranged in an arc shape around the outer peripheral side of the second liquid injection hole. The plurality of sub-plates are arranged at intervals, and the sub-plates are connected to the main body. One end of the sub-plate away from the main body is connected to the baffle plate, and two adjacent sub-plates, the baffle plate and the main body enclose a liquid outlet.

15. The secondary battery according to claim 11, characterized in that: The side surface of the baffle plate facing the second liquid injection hole is one of a plane, an arc surface protruding toward the second liquid injection hole, and a conical surface protruding toward the second liquid injection hole.

16. A battery pack, characterized in that: Comprising the secondary battery as claimed in any one of claims 1 to 15.

17. An electrical device, characterized in that: Comprising the secondary battery as described in any one of claims 1 to 15, or the battery pack as described in claim 16.

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