Secondary battery and battery pack

Abstract

The utility model discloses a secondary battery and a battery pack, and belongs to the technical field of batteries, the secondary battery comprises a shell, a cover plate assembly, an electrode assembly and an insulating piece, the cover plate assembly comprises a plate body, a plugging piece, a pole and a connecting piece, the plate body has a thickness direction and a length direction, the plate body is connected with the shell and covers a containing cavity, and the plate body is provided with a mounting hole; the plugging piece is connected with the plate body and covers and seals the mounting hole; the pole penetrates through the plate body; the connecting piece is arranged in the accommodating cavity and connected with the pole, part of the connecting piece faces the plugging piece in the thickness direction, and the connecting piece and the plugging piece are spaced to form a first gap; the electrode assembly comprises a tab, and part of the tab is arranged in the first gap and fixedly connected with the connecting piece; the insulating part is arranged in the first gap and is connected with the fixed tab; the insulating part is arranged in the first gap, so that the tab and the plugging part can be isolated, short circuit caused by contact between the tab and the plugging part when the secondary battery shakes is avoided, and the reliability of the secondary battery is improved.

Description

Technical Field

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

[0002] During the installation of some secondary batteries, it is necessary to connect the tabs to the connecting pieces through the installation holes on the top cover, and then use a sealing member to close the installation holes to achieve sealing inside the secondary battery.

[0003] However, after the mounting hole is closed, although there is a gap between the tab and the sealing piece, after the secondary battery shakes, the electrode assembly will move inside the secondary battery, and the tab may contact the sealing piece and cause a short circuit, affecting the reliability of the secondary battery. Utility Model Content

[0004] Purpose of the utility model: The present application provides a secondary battery for solving the technical problem that the tab contacts the sealing member and causes a short circuit; another purpose of the present application is to provide a battery pack.

[0005] Technical solution: This application provides a secondary battery, including:

[0006] A housing having a receiving cavity;

[0007] The cover plate assembly includes a plate body, a blocking piece, a pole and a connecting piece, wherein the plate body has a thickness direction and a length direction, the plate body is connected to the shell and covers the accommodating cavity, the plate body has a mounting hole that passes through the plate body along the thickness direction, and the mounting hole is communicated with the accommodating cavity; the blocking piece is connected to the plate body and covers the mounting hole; the pole is provided through the plate body, and the pole and the blocking piece are spaced apart along the length direction; the connecting piece is provided in the accommodating cavity and connected to the pole, a portion of the connecting piece faces the blocking piece along the thickness direction, and a first gap is formed between the connecting piece and the blocking piece;

[0008] an electrode assembly disposed in the accommodating cavity, the electrode assembly comprising a body and a tab connected to each other, wherein a portion of the tab is disposed in the first gap and fixedly connected to the connecting sheet;

[0009] An insulating member, at least a portion of which is disposed in the first gap, located between the tab and the blocking member, and connected to the tab.

[0010] In some embodiments, the tab includes a first portion and a second portion connected to each other, the first portion is connected to the body, and the second portion is disposed in the first gap and is respectively connected to the connecting piece and the insulating member.

[0011] In some embodiments, the plate body also has a width direction that intersects both the thickness direction and the length direction; the secondary battery includes a plurality of electrode assemblies arranged along the width direction, the first portions of the plurality of electrode assemblies are spaced apart along the width direction and form a second gap, and a portion of the insulating member is arranged in the second gap.

[0012] In some embodiments, the connecting sheet has a connecting hole; the first portions of the plurality of electrode assemblies are passed through the connecting hole; and a portion of the insulating member is passed through the connecting hole.

[0013] In some embodiments, the insulating member comprises:

[0014] a first insulating portion, the first insulating portion being located in the first gap and connected to the second portion;

[0015] The second insulating portion is connected to a side of the first insulating portion facing the main body along the thickness direction, and the second insulating portion is passed through the connecting hole and is disposed in the second gap.

[0016] In some embodiments, along the width direction, two first insulating portions connected to two adjacent second portions are spaced apart; and the second insulating portion connects two adjacent first insulating portions.

[0017] In some embodiments, the secondary battery further includes a separator, which is disposed in the first gap. The separator is located between the blocking member and the insulating member along a thickness direction and is connected to the blocking member.

[0018] In some embodiments, the plate body has a fifth surface and a sixth surface that face away from each other along the thickness direction, the sixth surface faces the accommodating cavity, the mounting hole forms a first opening on the fifth surface, and the mounting hole forms a second opening on the sixth surface, and the hole wall of the mounting hole is inclined to the thickness direction so that the size of the first opening is larger than the size of the second opening.

[0019] In some embodiments, the sealing member has a third surface and a fourth surface that are opposite to each other along the thickness direction, and the fourth surface faces the accommodating cavity; the sealing member also includes a side wall, which is located between the third surface and the fourth surface and is connected to the third surface and the fourth surface respectively, and the side wall is arranged to be inclined to the thickness direction so that the side wall can fit with the hole wall.

[0020] Correspondingly, the present application also provides a battery pack, comprising a secondary battery as described in any one of the above embodiments.

[0021] Beneficial effect: Compared with the prior art, the secondary battery provided in the embodiment of the present application includes a shell, a cover assembly, an electrode assembly and an insulating member, the shell has a accommodating cavity; the cover assembly includes a plate body, a sealing member, a pole and a connecting piece, the plate body has a thickness direction and a length direction, the plate body is connected to the shell and covers the accommodating cavity, the plate body has a mounting hole that passes through the plate body along the thickness direction, and the mounting hole is connected to the accommodating cavity; the sealing member is connected to the plate body and covers the mounting hole; the pole is passed through the plate body, and the pole and the sealing member are spaced apart along the length direction; the connecting piece is arranged in the accommodating cavity and connected to the pole, part of the connecting piece faces the sealing member along the thickness direction, and a first gap is formed between the connecting piece and the sealing member; the electrode assembly is arranged in the accommodating cavity, the electrode assembly includes a main body and a pole ear that are connected to each other, part of the pole ear is arranged in the first gap, and is connected to the connecting piece; at least part of the insulating member is arranged in the first gap, and is located between the pole ear and the sealing member, and is connected to the fixed pole ear. The present application provides an insulating member in the first gap to isolate the tab and the blocking member, preventing the tab and the blocking member from contacting and causing a short circuit when the secondary battery is shaken, thereby improving the reliability of the secondary battery. Furthermore, the present application also secures the insulating member by connecting it to the fixed tab, preventing the insulating member from falling out of the first gap.

[0022] Correspondingly, the present application also provides a battery pack, which includes the secondary battery of any one of the above embodiments. Since the probability of short circuit in the secondary battery is reduced, the reliability of the battery pack is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0024] Figure 1 A schematic structural diagram of a secondary battery provided in an embodiment of the present application without a blocking member;

[0025] Figure 2 A top view of a secondary battery provided in an embodiment of the present application with the sealing member hidden;

[0026] Figure 3 A top view of the secondary battery provided in an embodiment of the present application with the blocking member and the insulating member hidden;

[0027] Figure 4 for Figure 2 Cross-sectional view at AA in the middle;

[0028] Figure 5 for Figure 4 Detailed view of the center frame C;

[0029] Figure 6 for Figure 2 Cross-sectional view at the middle BB;

[0030] Figure 7 for Figure 6 Detail of box D.

[0031] Figure markings, 100-shell, 110-accommodating cavity, 111-first gap, 112-second gap, 200-cover assembly, 210-plate body, 211-mounting hole, 212-fifth surface, 213-sixth surface, 214-first opening, 215-second opening, 216-hole wall, 220-sealing member, 221-third surface, 222-fourth surface, 223-side wall, 230-pole, 240-connecting plate, 241-first surface, 242-second surface, 243-connecting hole, 250-electrode assembly, 251-body, 252-ear, 2521-first part, 2522-second part, 300-insulating member, 310-first insulating part, 320-second insulating part, 400-isolating member. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0033] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly specified and specifically limited. 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. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0034] It should also be noted that in the drawings of the embodiments of the present application, the arrows marked X, Y, and Z respectively represent the thickness direction X, the width direction Y, and the length direction Z. The description of the present application introduces the thickness direction X, the width direction Y, and the length direction Z in order to more clearly express the relative positional relationship involved in the embodiments of the application, wherein the thickness direction X, the width direction Y, and the length direction Z are three relative directions that intersect with each other, rather than absolute directions. In actual applications, the thickness direction X, the width direction Y, and the length direction Z can point to any direction in space as long as the intersection relationship between the two is maintained.

[0035] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application.

[0036] During the installation of some secondary batteries, it is necessary to connect the tabs to the connecting pieces through the installation holes on the top cover, and then use a sealing member to close the installation holes to achieve sealing inside the secondary battery.

[0037] However, after the mounting hole is closed, although there is a gap between the tab and the sealing piece, after the secondary battery shakes, the electrode assembly will move inside the secondary battery, and the tab may contact the sealing piece and cause a short circuit, affecting the reliability of the secondary battery.

[0038] In order to solve the technical problem that the tab contacts the blocking member and causes a short circuit, the first embodiment of the present application provides a secondary battery. Figure 1 、 Figure 2 、 Figure 4 and 6 The secondary battery includes a housing 100, a cover assembly 200, an electrode assembly 250, and an insulating member 300. The housing 100 has a receiving cavity 110; the cover assembly 200 includes a plate 210, a blocking member 220, a terminal 230, and a connecting piece 240. The plate 210 has a thickness direction X and a length direction Z. The plate 210 is connected to the housing 100 and covers the receiving cavity 110. The plate 210 has a mounting hole 211 that passes through the plate 210 along the thickness direction X. The mounting hole 211 is connected to the receiving cavity 110; see Figure 6 and Figure 7 , the blocking member 220 is connected to the plate body 210 and covers the mounting hole 211, wherein, in order to show the insulating member 300 in the accommodating cavity 110, Figure 1The blocking piece 220 in the figure has been hidden; the pole 230 is provided through the plate body 210, and the pole 230 and the blocking piece 220 are spaced apart along the length direction Z; the connecting piece 240 is provided in the accommodating cavity 110 and connected to the pole 230, and a portion of the connecting piece 240 faces the blocking piece 220 along the thickness direction X, and a first gap 111 is formed between the connecting piece 240 and the blocking piece 220; the electrode assembly 250 is provided in the accommodating cavity 110, and the electrode assembly 250 includes a body 251 and a pole ear 252 that are connected to each other, and a portion of the pole ear 252 is provided in the first gap 111 and is fixedly connected to the connecting piece 240; please refer to Figure 4 and Figure 5 At least a portion of the insulating member 300 is disposed in the first gap 111 , and is located between the tab 252 and the blocking member 220 , and is fixedly connected to the tab 252 .

[0039] The plate body has a fifth surface 212 and a sixth surface 213. The fifth surface 212 and the sixth surface 213 face away from each other along the thickness direction X, and the sixth surface 213 faces the accommodating cavity 110. The portion of the connecting piece 240 facing the blocking member 220 along the thickness direction X means that, along the thickness direction X, the orthographic projection of the connecting piece 240 on the plane where the sixth surface 213 lies overlaps with the orthographic projection of the blocking member 220 on the plane where the sixth surface 213 lies.

[0040] See also Figure 5 and Figure 7 , the space of the first gap 111 is relatively small. When the electrode assembly 250 moves relative to the cover plate assembly 200 and toward the cover plate assembly 200, there is a risk that the tab 252 will contact the blocking member 220, thereby causing a short circuit. In the above embodiment, the insulating member 300 provided in the first gap 111 can isolate the tab 252 from the blocking member 220. Even if the tab 252 moves toward the blocking member 220 driven by the electrode assembly 250, it will not contact the blocking member 220 due to the presence of the insulating member 300, thereby reducing the possibility of the tab 252 contacting the blocking member 220 and causing a short circuit, thereby improving the reliability of the secondary battery. In addition, in the above embodiment, the insulating member 300 is fixedly connected to the tab 252 to achieve fixation, thereby preventing the insulating member 300 from being separated from the first gap 111 and improving the insulation reliability of the insulating member 300. In the production process of the above embodiment, after the tab 252 and the connecting piece 240 are welded, the insulating member 300 is placed into the accommodating cavity 110 through the mounting hole 211, and the insulating member 300 is attached to the tab 252. The sealing member 220 then seals the mounting hole 211. It is understandable that the welding of the tab 252 and the connecting piece 240 may generate impurities that may fall off. However, the insulating member 300 attached to the tab 252 can cover the weld marks and adhere and fix the impurities, preventing the impurities from falling off and causing a short circuit, further reducing the possibility of a short circuit in the secondary battery and further improving the reliability of the secondary battery.

[0041] In some embodiments, see Figure 4 and Figure 5 The tab 252 includes a first portion 2521 and a second portion 2522 connected to each other. The first portion 2521 is connected to the body 251 , and the second portion 2522 is disposed in the first gap 111 and connected to the connecting piece 240 and the insulating member 300 , respectively.

[0042] Specifically, the second portion 2522 is located between the connecting piece 240 and the insulating member 300 along the thickness direction X, connecting the connecting piece 240 and the insulating member 300. Furthermore, the first portion 2521 is located between the second portion 2522 and the body 251 along the thickness direction X, connecting the second portion 2522 and the body 251. In other words, along the thickness direction X, the first portion 2521 is located on the side of the second portion 2522 that is farther away from the blocking member 220. This means that the second portion 2522 is closer to the blocking member 220 than the first portion 2521 and is more likely to come into contact with the blocking member 220.

[0043] In the above embodiment, the present application can minimize the probability of contact between the tab 252 and the blocking member 220 by setting an insulating member 300 between the second portion 2522, which has a higher probability of contact with the blocking member 220, and the blocking member 220, thereby further reducing the possibility of internal short circuit in the secondary battery and further improving the reliability of the secondary battery.

[0044] In some embodiments, please refer again to Figure 4 and Figure 5 The plate 210 also has a width direction Y that intersects both the thickness direction X and the length direction Z; the secondary battery includes a plurality of electrode assemblies 250 arranged along the width direction Y, and the first portions 2521 of the plurality of electrode assemblies 250 are arranged at intervals along the width direction Y to form a second gap 112, and a portion of the insulating member 300 is arranged in the second gap 112.

[0045] It is understandable that during the shaking of the secondary battery, relative movement may occur between the multiple electrode assemblies 250 inside the secondary battery, and friction may occur between the tabs 252 belonging to different electrode assemblies 250, causing wear of the tabs 252. In the above embodiment, by providing the portion of the insulating member 300 between the second gap 112, i.e., between the first portions 2521 of adjacent electrode assemblies 250, the insulating member 300 can isolate the first portions 2521 of adjacent electrode assemblies 250, thereby preventing the first portions 2521 of adjacent electrode assemblies 250 from rubbing against each other, causing wear of the tabs 252, thereby improving the reliability of the secondary battery. In addition, please refer again to Figure 5It can be understood that since the second gap 112 is located between the first parts 2521 of adjacent electrode assemblies 250, and the insulating member 300 is recessed from the side of the second part 2522 away from the first part 2521 toward the second gap 112, the insulating member 300 can also isolate the second parts 2522 of adjacent electrode assemblies 250, avoiding mutual friction between the second parts 2522 of adjacent electrode assemblies 250 and causing wear of the tabs 252, thereby improving the reliability of the secondary battery.

[0046] In some embodiments, please refer again to Figure 5 The connecting piece 240 has a connecting hole 243 ; the first portions 2521 of the plurality of electrode assemblies 250 are passed through the connecting hole 243 ; and a portion of the insulating member 300 is passed through the connecting hole 243 .

[0047] The length of the electrode tab 252 can be reduced by guiding the electrode tab 252 from the connecting hole 243 to the first gap 111. In the above embodiment, by also passing a portion of the insulating member 300 through the connecting hole 243, the portion of the insulating member 300 in the second gap 112 is made larger in the thickness direction X, thereby making the insulating member 300 more effective in isolating the electrode tabs 252 of adjacent electrode assemblies 250.

[0048] In some embodiments, the insulating member 300 includes a first insulating portion 310 and a second insulating portion 320, the first insulating portion 310 is located in the first gap 111 and is connected to the second portion 2522; the second insulating portion 320 is connected to the side of the first insulating portion 310 facing the main body 251 along the thickness direction X, the second insulating portion 320 is passed through the connecting hole 243, and is arranged in the second gap 112.

[0049] In the above embodiment, the first insulating portion 310 is used to isolate and prevent the tabs 252 from contacting the blocking member 220 and causing a short circuit, and the second insulating portion 320 is used to isolate and prevent adjacent tabs 252 along the width direction Y from rubbing against each other and causing wear, thereby improving the reliability of the secondary battery.

[0050] In some embodiments, please refer again to Figure 5 , along the width direction Y, the two first insulating portions 310 connected to the two adjacent second portions 2522 are spaced apart; the second insulating portion 320 connects the two adjacent first insulating portions 310 .

[0051] It can be understood that in the above embodiment, multiple first insulating parts 310 belong to the same insulating member 300. When the insulating member 300 is connected to the pole ear 252, only one operation is required to isolate the multiple pole ears 252 from the blocking member 220, thereby reducing the assembly steps of the secondary battery, reducing the assembly difficulty of the secondary battery, and improving the assembly efficiency of the secondary battery.

[0052] In some embodiments, see Figure 6 and Figure 7 The secondary battery further includes a separator 400 . The separator 400 is disposed in the first gap 111 . The separator 400 is located between the blocking member 220 and the insulating member 300 along the thickness direction X and is connected to the blocking member 220 .

[0053] In the above embodiment, the possibility of contact between the tab 252 and the blocking member 220 can be reduced by providing the spacer 400 within the first gap 111. In addition, the possibility of contact between the tab 252 and the blocking member 220 can be further reduced by providing both the insulating member 300 and the spacer 400 within the first gap 111, thereby improving the reliability of the secondary battery.

[0054] In some embodiments, the plate body 210 has a fifth surface 212 and a sixth surface 213 that face away from each other along the thickness direction X, the sixth surface 213 faces the accommodating cavity 110, the mounting hole 211 forms a first opening 214 on the fifth surface 212, and the mounting hole 211 forms a second opening 215 on the sixth surface 213, and the hole wall 216 of the mounting hole 211 is inclined to the thickness direction X so that the size of the first opening 214 is larger than the size of the second opening 215.

[0055] In the above embodiment, please refer again to Figure 6 and Figure 7 The smaller size of the second opening 215 than the first opening 214 prevents the blocking member 220 from passing through the second opening 215. During installation, when using the blocking member 220 to seal the mounting hole 211, simply place the blocking member 220 on the hole wall 216 before welding the blocking member 220 to the plate 210. Because the blocking member 220 cannot pass through the second opening 215, it will not fall into the accommodating cavity 110, reducing the difficulty of securing the blocking member 220 during welding.

[0056] In some embodiments, the hole wall 216 of the mounting hole 211 is a cylindrical surface; in other embodiments, the hole wall 216 of the mounting hole 211 is a quadrangular pyramid surface.

[0057] In some embodiments, please refer again to Figure 6 and Figure 7 The blocking member 220 has a third surface 221 and a fourth surface 222 that are opposite to each other along the thickness direction X, and the fourth surface 222 faces the accommodating cavity 110; the blocking member 220 also includes a side wall 223, which is located between the third surface 221 and the fourth surface 222, and is connected to the third surface 221 and the fourth surface 222 respectively. The side wall 223 is arranged to be inclined to the thickness direction X so that the side wall 223 can fit with the hole wall 216.

[0058] In the above embodiment, the side wall 223 arranged obliquely to the thickness direction X can fit with the hole wall 216, so that when the blocking member 220 is placed in the mounting hole 211, the hole wall 216 can play a positioning role for the blocking member 220, thereby further reducing the difficulty of positioning the blocking member 220 before welding, thereby further reducing the difficulty of welding the blocking member 220.

[0059] In some embodiments, see Figure 5 The secondary battery has a width direction Y that intersects both the thickness direction X and the length direction Z. Along the width direction Y, the minimum distance between the insulating member 300 and the shell 100 is D1 mm, and the minimum distance between the tab 252 and the shell 100 is D2 mm, satisfying: 2≤D2-D1≤2.5.

[0060] It can be understood that D2 - D1 > 0, that is, one end of the insulating member 300 extends beyond the tab 252 , so that the insulating member 300 can completely cover the tab 252 , and the insulating member 300 can isolate the tab 252 and the blocking member 220 as much as possible.

[0061] Specifically, the value of D2-D1 can be any one of 2, 2.1, 2.2, 2.3, 2.4, and 2.5, or a range between any two values. When the value of D2-D1 is small, it can prevent the insulating member 300 from adhering to other connectors during installation, thereby avoiding the need to remove and repeatedly reconnect the insulating member 300, thereby improving the assembly efficiency of the secondary battery. When the value of D2-D1 is large, it can prevent the insulating member 300 from not fully covering the tab 252 due to installation errors, thereby improving the reliability of the secondary battery.

[0062] In the above embodiment, when the value of D2-D1 is within the range defined by the embodiment, it can ensure that the insulating member 300 can completely cover the tab 252 to ensure the reliability of the secondary battery, and can also reduce the difficulty of assembling the secondary battery and improve the assembly efficiency of the secondary battery.

[0063] It is understood that in other embodiments, when D2-D1>0 is satisfied, the minimum distance between the insulating member 300 and the housing 100 along the length direction Z is smaller than the minimum distance between the tab 252 and the housing 100. This further ensures that the insulating member 300 can completely cover the tab 252, thereby guaranteeing the reliability of the secondary battery.

[0064] In some embodiments, see Figure 2The secondary battery also has a width direction Y, and the thickness direction X, the width direction Y and the length direction Z intersect with each other; along the length direction Z, the minimum distance between the hole wall 216 of the mounting hole 211 and the shell 100 is D4 mm, and the minimum distance between the insulating member 300 and the shell 100 is D5 mm; along the width direction Y, the minimum distance between the hole wall 216 of the mounting hole 211 and the shell 100 is D6 mm, and the minimum distance between the insulating member 300 and the shell 100 is D7 mm, satisfying: 1.5≤D5-D4≤2, 2≤D7-D6≤2.5.

[0065] Specifically, the value of D5-D4 can be any one of 1.5, 1.6, 1.7, 1.8, 1.9, or 2, or a range between any two values. When the value of D5-D4 is small, the size of the mounting hole 211 is small, and the mechanical properties of the plate 210 are better. When the value of D5-D4 is large, the size of the mounting hole 211 is larger than that of the insulating member 300, which facilitates welding of the tab 252 and installation of the insulating member 300.

[0066] Specifically, the value of D7-D6 can be any one of 2, 2.1, 2.2, 2.3, 2.4, and 2.5, or a range between any two values. When the value of D7-D6 is small, the size of the mounting hole 211 is small, and the mechanical properties of the plate 210 are better. When the value of D7-D6 is large, the size of the mounting hole 211 is larger than that of the insulating member 300, which facilitates welding of the tab 252 and installation of the insulating member 300.

[0067] In the above embodiment, when the values of D5-D4 and the values of D7-D6 are both within the ranges defined in the embodiment, the plate 210 can have better mechanical properties and the difficulty of assembling the secondary battery can be reduced.

[0068] In some embodiments, the secondary battery further has a width direction Y, and the thickness direction X, the width direction Y, and the length direction Z intersect with each other; the plate body 210 has a maximum dimension L0 mm along the width direction Y, the mounting hole 211 has a minimum dimension L3 mm along the width direction Y, and the mounting hole 211 has a minimum dimension L4 mm along the length direction Z, satisfying: 3≤L0-L3≤4, 3≤L0-L4≤4.

[0069] Specifically, the value of L0-L3 can be any one of 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, and 4.0, or a range between any two values. When the value of L0-L3 is smaller, the size of the mounting hole 211 is larger, making it easier to weld the tab 252 and install the insulating member 300. When the value of L0-L3 is larger, the size of the mounting hole 211 is smaller, and the mechanical properties of the plate body 210 are better.

[0070] Specifically, the value of L0-L4 can be any one of 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, and 4.0, or a range between any two values. When the value of L0-L4 is smaller, the size of the mounting hole 211 is larger, making it easier to weld the tab 252 and install the insulating member 300. When the value of L0-L4 is larger, the size of the mounting hole 211 is smaller, and the mechanical properties of the plate body 210 are better.

[0071] In the above embodiment, when the values of L0-L3 and L0-L4 are both within the range defined in the embodiment, the plate 210 can have better mechanical properties and the difficulty of assembling the secondary battery can be reduced.

[0072] Correspondingly, the present application also provides a battery pack, which includes the secondary battery of any one of the above embodiments. Since the probability of short circuit in the secondary battery is reduced, the reliability of the battery pack is higher.

[0073] The above is a detailed introduction to a secondary battery and a battery pack provided in the embodiments of the present application. Specific examples are used in the present application 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 solutions and core ideas 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 make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A secondary battery, characterized in that: The secondary battery includes: A housing having a receiving cavity; The cover plate assembly includes a plate body, a blocking piece, a pole and a connecting piece, wherein the plate body has a thickness direction and a length direction, the plate body is connected to the shell and covers the accommodating cavity, the plate body has a mounting hole that passes through the plate body along the thickness direction, and the mounting hole is communicated with the accommodating cavity; the blocking piece is connected to the plate body and covers the mounting hole; the pole is provided through the plate body, and the pole and the blocking piece are spaced apart along the length direction; the connecting piece is provided in the accommodating cavity and connected to the pole, a portion of the connecting piece faces the blocking piece along the thickness direction, and a first gap is formed between the connecting piece and the blocking piece; an electrode assembly disposed in the accommodating cavity, the electrode assembly comprising a body and a tab connected to each other, wherein a portion of the tab is disposed in the first gap and fixedly connected to the connecting sheet; An insulating member, at least a portion of which is disposed in the first gap, located between the tab and the blocking member, and fixedly connected to the tab.

2. The secondary battery according to claim 1, wherein The tab includes a first portion and a second portion connected to each other, wherein the first portion is connected to the body, and the second portion is disposed in the first gap and is respectively connected to the connecting piece and the insulating member.

3. The secondary battery according to claim 2, wherein The plate body also has a width direction that intersects with both the thickness direction and the length direction; the secondary battery includes a plurality of electrode assemblies arranged along the width direction, the first portions of the plurality of electrode assemblies are spaced apart along the width direction and form a second gap, and part of the insulating member is arranged in the second gap.

4. The secondary battery according to claim 3, wherein The connecting piece has a connecting hole; the first parts of the plurality of electrode assemblies are passed through the connecting hole; and part of the insulating member is passed through the connecting hole.

5. The secondary battery according to claim 4, wherein The insulating member comprises: a first insulating portion, the first insulating portion being located in the first gap and connected to the second portion; The second insulating portion is connected to a side of the first insulating portion facing the main body along the thickness direction, and the second insulating portion is passed through the connecting hole and is disposed in the second gap.

6. The secondary battery according to claim 5, characterized in that Along the width direction, two first insulating portions connected to two adjacent second portions are spaced apart; and the second insulating portion connects two adjacent first insulating portions.

7. The secondary battery according to claim 1, wherein The secondary battery further includes a separator, which is disposed in the first gap. The separator is located between the blocking member and the insulating member along a thickness direction and is connected to the blocking member.

8. The secondary battery according to claim 1, wherein The plate body has a fifth surface and a sixth surface that face away from each other along the thickness direction, the sixth surface faces the accommodating cavity, the mounting hole forms a first opening on the fifth surface, and the mounting hole forms a second opening on the sixth surface, and the hole wall of the mounting hole is arranged to be inclined to the thickness direction so that the size of the first opening is larger than the size of the second opening.

9. The secondary battery according to claim 8, characterized in that The sealing member has a third surface and a fourth surface that are opposite to each other along the thickness direction, and the fourth surface faces the accommodating cavity; the sealing member also includes a side wall, which is located between the third surface and the fourth surface and is connected to the third surface and the fourth surface respectively, and the side wall is arranged to be inclined with respect to the thickness direction so that the side wall can fit with the hole wall.

10. A battery pack, characterized in that: The invention comprises the secondary battery according to any one of claims 1 to 9.

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