Single battery and battery pack

Abstract

The invention discloses a single battery and a battery pack, and belongs to the technical field of batteries, and the single battery comprises a shell, an electrode assembly, a cover plate assembly, a sealing plate and a sealing piece, the pole column comprises a pole column body and a pole column base, the pole column body penetrates through the pole column hole and is connected with the pole column base in the height direction, the pole column base is close to the electrode assembly, and the pole column base is provided with a through hole penetrating in the height direction; the tab partially penetrates through the through hole and is fixedly connected with the pole base; the sealing piece surrounds the pole base and abuts against the cover plate body and the pole base; the pole is provided with a first matching surface, the first matching surface is inclined relative to the height direction, and the sealing piece is connected with the first matching surface. The tab does not need to be folded, and the tab directly penetrates through the through hole and is welded with the pole base, so that the distance between the electrode main body and the cover plate assembly is reduced. The inclined first matching surface is arranged, so that the rebound force of the sealing element is dispersed to the pole base, the pole base can be thinned, and the energy density is improved.

Description

Technical Field

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

[0002] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, single batteries, as the power source of electric vehicles, play an irreplaceable and important role.

[0003] With the development and application of battery technology, the energy density requirements for single cells are increasing. Summary of the invention

[0004] Purpose of the invention: The embodiments of the present application provide a single cell battery and a battery pack, aiming to solve the technical problem of improving the energy density of the single cell battery.

[0005] Technical solution: The present application embodiment provides a single battery, including:

[0006] A housing having a receiving cavity;

[0007] The electrode assembly is located in the accommodating cavity, and the electrode assembly includes an electrode body and an electrode ear connected to each other;

[0008] The cover plate assembly has an intersecting height direction and a length direction, and the cover plate assembly includes a cover plate body and a pole, the cover plate body is connected to the shell and covers the accommodating cavity, the cover plate body has a pole hole penetrating along the height direction, and the pole is inserted into the pole hole;

[0009] The pole includes a pole body and a pole base. The pole body is inserted into the pole hole and connected to the pole base in the height direction. The pole base is close to the electrode assembly and has a through hole extending in the height direction. A portion of the pole ear is inserted into the through hole and fixedly connected to the pole.

[0010] A sealing member surrounds the pole base and abuts against the cover body and the pole base;

[0011] The pole base has a first mating surface, the first mating surface is inclined relative to the height direction, and the sealing element is connected to the first mating surface.

[0012] In some embodiments, the cover body has a second mating surface, the second mating surface is located in the pole hole (300) and is inclined relative to the height direction, the second mating surface and the first mating surface are arranged opposite to each other along the length direction, and the sealing member is connected to the second mating surface and the first mating surface respectively.

[0013] In some embodiments, the seal surrounds the pole body and abuts the cover body and the pole body; the pole body has a third mating surface, the third mating surface is connected to the first mating surface and inclined relative to the height direction, and the seal is connected to the third mating surface.

[0014] In some embodiments, the single cell includes a first insulating member, which is located on a side of the cover body away from the electrode assembly. A portion of the first insulating member passes through the pole hole and surrounds the pole body. The first insulating member fixedly connects the pole body and the cover body; along the height direction, the first insulating member abuts against the sealing member.

[0015] In some embodiments, the cover plate body includes a first protrusion, which protrudes toward a side away from the electrode assembly and surrounds the electrode hole;

[0016] The first insulating member has a first groove on one side close to the electrode assembly for the first protrusion to be embedded.

[0017] In some embodiments, the first insulating member includes a clamping portion, which is located in the first groove and protrudes toward a side close to the electrode assembly, and the first protruding portion has a notch portion for the clamping portion to be embedded in.

[0018] In some embodiments, the first insulating member includes a second protrusion, and the second protrusion protrudes toward a side close to the pole;

[0019] A side of the pole close to the first insulating member has a second groove for the second protrusion to be embedded in.

[0020] In some embodiments, the dimension of the pole ear in the height direction is H1 mm, the maximum dimension of the pole base in the height direction is H2 mm, the minimum dimension of the pole base in the height direction is H3 mm, and the dimension between the electrode body and the pole base is H4 mm, satisfying:

[0021]

[0022] In some embodiments, the single battery includes a limiting member, the limiting member includes a first limiting portion and a second limiting portion, and a portion of the tab is located between the first limiting portion and the second limiting portion and is connected to the first limiting portion and the second limiting portion, respectively.

[0023] In some embodiments, the pole body has a slot that penetrates along the height direction, and the slot is connected to the through hole; the single battery includes a sealing plate, which is connected to the pole body and covers the slot.

[0024] In some embodiments, the single battery includes a first insulating layer surrounding the electrode ear and connected to the electrode body, and the orthographic projection of the electrode base along the height direction is located in the first insulating layer.

[0025] In some embodiments, the single battery pack includes a second insulating layer, and the second insulating layer is located between the electrode body and the shell and covers the electrode body.

[0026] Accordingly, an embodiment of the present application provides a battery pack, comprising the above-mentioned single battery.

[0027] Beneficial effects: The single cell of the embodiment of the present application includes a shell, an electrode assembly, a cover assembly, a sealing plate and a seal. The shell has a housing cavity; the electrode assembly is located in the housing cavity, and the electrode assembly includes an electrode body and a pole ear connected to each other; the cover assembly has an intersecting height direction and a length direction, and the cover assembly includes a cover body and a pole, the cover body is connected to the shell and covers the housing cavity, the cover body has a pole hole penetrating in the height direction, and the pole is penetrated in the pole hole; the pole includes a pole body and a pole base, the pole body is penetrated in the pole hole, and is connected to the pole base in the height direction, the pole base is close to the electrode assembly, and the pole base has a through hole penetrating in the height direction, a part of the pole ear is penetrated in the through hole and fixedly connected to the pole base, thereby realizing the electrical connection between the electrode body and the pole. In this way, there is no need to fold the pole ear, and the pole ear can be directly penetrated in the through hole and welded to the pole to realize the electrical connection between the pole and the electrode body, which can effectively reduce the distance between the electrode body and the cover assembly, improve the space utilization rate, and thus improve the energy density.

[0028] Since the thickness of the pole base will also affect the energy density, the seal in the present application surrounds the pole base and abuts the cover plate body and the pole base; wherein the pole base has a first mating surface, the first mating surface is inclined relative to the height direction, and the seal is connected to the first mating surface. The present application sets an inclined first mating surface to connect with the seal, so that the rebound force of the seal can be dispersed to the pole base, thereby reducing the force on the pole base, and then reducing the thickness of the pole base, reducing the space occupied by the pole base in the height direction, and further improving the energy density of the single battery.

[0029] The battery pack of the embodiment of the present application includes the above-mentioned single battery, so the battery pack can have all the technical features and beneficial effects of the above-mentioned single battery, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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.

[0031] Figure 1 is a schematic structural diagram of a single cell according to an embodiment of the present application;

[0032] Figure 2 is an exploded diagram of a single cell of an embodiment of the present application;

[0033] Figure 3 is a schematic structural diagram of an electrode assembly according to an embodiment of the present application;

[0034] Figure 4 yes Figure 3 A magnified view of part A;

[0035] Figure 5 is a schematic structural diagram of a single cell according to another embodiment of the present application;

[0036] Figure 6 yes Figure 5 BB cross-sectional view;

[0037] Figure 7 yes Figure 6 Enlarged view of part C;

[0038] Figure 8 is a top view of a cover plate assembly according to an embodiment of the present application;

[0039] Fig. 9 yes Figure 8 A magnified view of the D portion;

[0040] Fig.10 is an exploded view of a single cell according to another embodiment of the present application;

[0041] Fig.11 is a structural schematic diagram of a cover plate assembly according to an embodiment of the present application;

[0042] Fig.12 yes Fig.11 EE cross-sectional view;

[0043] Fig.13 yes Fig.12 Magnified view of part F;

[0044] Fig.14 It is a structural schematic diagram of a cover plate body according to an embodiment of the present application;

[0045] Fig.15 is a structural schematic diagram of a first insulating member in an embodiment of the present application;

[0046] Fig.16 It is a schematic diagram of the structure of a pole according to an embodiment of the present application.

[0047] Figure numerals: 1, shell; 2, electrode assembly; 3, cover plate assembly; 4, sealing member; 5, first insulating member; 6, stopper; 7, first enclosed space; 8, second enclosed space; 9, first insulating layer; 10, second insulating layer; 11, second insulating member; 20, electrode body; 21, pole ear; 30, cover plate body; 31, pole; 50, first groove; 51, clamping part; 52, second protrusion; 60, first stopper; 61, second stopper; 100 , accommodating cavity; 210, positive pole ear; 211, negative pole ear; 300, pole hole; 301, second mating surface; 302, first protrusion; 310, through hole; 312, pole base; 313, pole body; 314, slot body; 315, sealing plate; 316, second groove; 317, positive pole; 318, negative pole; 3020, notch; 3120, first mating surface; 3130, third mating surface; X, height direction; Y, length direction. DETAILED DESCRIPTION

[0048] 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.

[0049] 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.

[0050] The applicant has noticed that with the development and application of battery technology, the energy density of batteries has been required to be increased. However, in some single cells, when the electrode body of the electrode assembly is connected to the pole, the pole ear needs to be folded for welding convenience, so a folding space needs to be left between the electrode body and the cover plate, and the electrical connection between the pole ear and the pole needs to be transferred by a connecting sheet, which occupies the height space between the electrode assembly and the cover plate assembly, resulting in space waste, which is not conducive to the improvement of battery energy density.

[0051] In view of this, the embodiment of the present application provides a single cell, including a shell, an electrode assembly, a cover assembly, a sealing plate and a seal. The shell has a housing cavity; the electrode assembly is located in the housing cavity, and the electrode assembly includes an electrode body and a pole ear connected to each other; the cover assembly has an intersecting height direction and a length direction, and the cover assembly includes a cover body and a pole, the cover body is connected to the shell and covers the housing cavity, the cover body has a pole hole penetrating in the height direction, and the pole is penetrated in the pole hole; the pole includes a pole body and a pole base, the pole body is penetrated in the pole hole, and is connected to the pole base in the height direction, the pole base is close to the electrode assembly, and the pole base has a through hole penetrating in the height direction, a part of the pole ear is penetrated in the through hole and is fixedly connected to the pole base, thereby realizing the electrical connection between the electrode body and the pole; the seal surrounds the pole base, and abuts the cover body and the pole base; wherein the pole base has a first mating surface, the first mating surface is inclined relative to the height direction, and the seal is connected to the first mating surface. With such a configuration, there is no need to fold the pole ear, and the pole ear can be directly inserted into the through hole and welded to the pole to achieve electrical connection between the pole and the electrode body, which can effectively reduce the distance between the electrode body and the cover assembly, improve space utilization, and thus improve energy density. In addition, the present application provides an inclined first mating surface to connect with the seal, so that the rebound force of the seal can be dispersed to the pole base, thereby reducing the force on the pole base, and then reducing the thickness of the pole base, reducing the space occupied by the pole base in the height direction, and thus improving the energy density of the single battery.

[0052] The single cell and battery pack of the present application are described in detail below in conjunction with the accompanying drawings. The features of the following embodiments and implementations can be combined with each other if there is no conflict.

[0053] Figure 1 is a schematic structural diagram of a single cell according to an embodiment of the present application; Figure 2 is an exploded diagram of a single cell of an embodiment of the present application; Figure 3 is a schematic structural diagram of an electrode assembly 2 according to an embodiment of the present application; Figure 4 yes Figure 3 A magnified view of part A; Figure 5 is a schematic structural diagram of a single cell according to another embodiment of the present application; Figure 6 yes Figure 5 BB cross-sectional view; Figure 7 yes Figure 6 Enlarged view of part C; Figure 8 is a top view of a cover plate assembly 3 according to an embodiment of the present application; Fig. 9 yes Figure 8 A magnified view of the D portion; Fig.10 is an exploded view of a single cell according to another embodiment of the present application; Fig.11 It is a structural schematic diagram of a cover plate assembly 3 according to an embodiment of the present application; Fig.12 yes Fig.11 EE cross-sectional view; Fig.13 yes Fig.12 Magnified view of part F;

[0054] Fig.14 is a structural schematic diagram of a cover plate body 30 according to an embodiment of the present application; Fig.15 is a schematic structural diagram of a first insulating member 5 according to an embodiment of the present application; Fig.16 It is a schematic diagram of the structure of a pole 31 according to an embodiment of the present application.

[0055] refer to Figures 1 to 16The embodiment of the present application provides a single cell, including a shell 1, an electrode assembly 2, a cover assembly 3, a sealing plate 315 and a sealing member 4. The shell 1 has a housing cavity 100; the electrode assembly 2 is located in the housing cavity 100, and the electrode assembly 2 includes an electrode body 20 and a pole ear 21 connected to each other; the cover assembly 3 has an intersecting height direction X and a length direction Y, and the cover assembly 3 includes a cover body 30 and a pole 31, the cover body 30 is connected to the shell 1 and covers the housing cavity 100, the cover body 30 has a pole hole 300 penetrating along the height direction X, and the pole 31 is penetrated in the pole hole 300; the pole 31 includes a pole body 313 and a pole base 312, the pole body 313 is penetrated in the pole hole 300, and is connected to the pole base 312. The seat 312 is connected along the height direction X, the pole base 312 is close to the electrode assembly 2, and the pole base 312 has a through hole 310 that penetrates along the height direction X, a part of the pole ear 21 is inserted through the through hole 310 and fixedly connected with the pole base 312, thereby realizing the electrical connection between the electrode body 20 and the pole 31; the seal 4 surrounds the pole base 312 and abuts against the cover body 30 and the pole base 312; wherein, the pole base 312 has a first mating surface 3120, the first mating surface 3120 is inclined relative to the height direction X, and the seal 4 is connected with the first mating surface 3120. In this arrangement, there is no need to fold the pole ear 21, and the pole ear 21 can be directly inserted into the through hole 310 and welded to the pole 31 to realize the electrical connection between the pole 31 and the electrode body 20, which can effectively reduce the distance between the electrode body 20 and the cover assembly 3, improve the space utilization rate, and thus improve the energy density. In addition, the present application sets an inclined first mating surface 3120 to connect with the seal 4, so that the rebound force of the seal 4 can be dispersed to the pole base 312, thereby reducing the force on the pole base 312, and then thinning the thickness of the pole base 312, reducing the space occupied by the pole base 312 in the height direction X, and then improving the energy density of the single cell.

[0056] exist Figure 7 and Fig.10In the illustrated embodiment, the cover body 30 has a second mating surface 301, which is located in the pole hole 300 and is inclined relative to the height direction X. The second mating surface 301 and the first mating surface 3120 are arranged opposite to each other along the length direction Y, and the seal 4 is connected to the second mating surface 301 and the first mating surface 3120 respectively. The present application provides an inclined second mating surface 301 and a first mating surface 3120 to clamp the seal 4, so that the rebound force of the seal 4 can be dispersed to the pole base 312 and the cover body 30, thereby further reducing the force on the pole base 312, and then reducing the thickness of the pole base 312, reducing the space occupied by the pole base 312 in the height direction X, and then improving the energy density of the single battery. In addition, the connection of the seal 4 with the second mating surface 301 and the first mating surface 3120 can improve the connection stability between the pole base 312 and the cover body 30.

[0057] exist Fig.16 In the illustrated embodiment, the seal 4 surrounds the pole body 313 and abuts the cover body 30 and the pole body 313; the pole body 313 has a third mating surface 3130, the third mating surface 3130 is connected to the first mating surface 3120 and is inclined relative to the height direction X, and the seal 4 is connected to the third mating surface 3130. By increasing the contact area between the seal 4 and the pole body 313, the inclined third mating surface 3130 can better disperse the rebound force of the seal 4, avoid pressure concentration, and improve the stability and reliability of the pole 31. In addition, the connection between the seal 4 and the third mating surface 3130 can improve the connection stability between the pole body 313 and the cover body 30.

[0058] exist Figure 7 In the illustrated embodiment, the pole body 313 has a slot 314 penetrating along the height direction X, and the slot 314 is connected to the through hole 310; the sealing plate 315 is connected to the pole body 313 and covers the slot 314. The sealing plate 315 blocks the slot 314 and is connected to the pole body 313 by laser welding or gluing, which can prevent debris from falling into the through hole 310 and the slot 314, causing pollution or short circuit.

[0059] exist Figure 7 , Fig.10 and Fig.14In the embodiment, at least part of the first mating surface 3120 is located on the peripheral side of the pole body 313, and the remaining part of the first mating surface 3120 is located on the peripheral side of the pole base 312. The first mating surface 3120 and the second mating surface 301 are arranged opposite to each other and are sealed and connected by the seal 4. Specifically, the first mating surface 3120 is arranged parallel to the second mating surface 301, and the abutment area between the seal 4 and the cover body 30, the pole body 313, and the pole base 312 is increased. Such arrangement, on the one hand, can enhance the limiting effect of the seal 4 in the horizontal direction; on the other hand, the rebound force of the seal 4 clamped between the second mating surface 301 and the first mating surface 3120 can be dispersed to the pole base 312 and the pole body 313, so that the force on the pole base 312 can be reduced, and then the thickness of the pole base 312 can be reduced, and the space occupied by the pole base 312 in the height direction X can be reduced, thereby improving the energy density of the single battery.

[0060] exist Figure 1 , Figure 2 , Figures 5 to 13 In the embodiment, the single cell includes a first insulating member 5, the first insulating member 5 is located on the side of the cover body 30 away from the electrode assembly 2, a part of the first insulating member 5 is passed through the pole hole 300 and surrounds the pole body 313, and the first insulating member 5 is fixedly connected to the pole body 313 and the cover body 30; along the height direction X, the first insulating member 5 abuts against the sealing member 4. The first insulating member 5 can be injection molded so that the first insulating member 5, the cover body 30 and the pole body 313 are connected to each other and achieve a sealed fit. The first insulating member 5 abuts against the sealing member 4 in the height direction X, which can further improve the limiting effect of the first insulating member 5 in the height direction X.

[0061] exist Fig.10 and Fig.13 In the illustrated embodiment, the cover body 30 includes a first protrusion 302, which protrudes toward a side away from the electrode assembly 2 and surrounds the pole hole 300; the first insulating member 5 has a first groove 50 for the first protrusion 302 to be embedded in the side close to the electrode assembly 2. The first protrusion 302 on the cover body 30 is embedded in the groove of the first insulating member 5, so that the first insulating member 5, the pole 31 and the cover body 30 are nested with each other, which can increase the connection stability.

[0062] In some embodiments, the first insulating member 5 includes a clamping portion 51, which is located in the first groove 50 and protrudes toward a side close to the electrode assembly 2. Fig.15 The first protrusion 302 has a notch 3020 for the clamping portion 51 to be embedded in. Fig.14As shown. The number of the clamping parts 51 can be multiple, and the multiple clamping parts 51 are arranged in the first groove 50 at intervals. Such an arrangement allows the first insulating member 5, the pole 31 and the cover plate assembly 3 to be better nested with each other, increase the torsion, improve the connection stability, help resist vibration and external force impact during the use of the single battery, and improve the safety and reliability of the battery single body.

[0063] In some embodiments, the first insulating member 5 includes a second protrusion 52, and the second protrusion 52 protrudes toward a side close to the pole 31. Fig.15 The pole 31 has a second groove 316 on one side close to the first insulating member 5 for embedding the second protrusion 52, as shown in FIG. Fig.16 As shown. The number of the second protrusions 52 can be multiple, and the multiple second protrusions 52 are arranged at intervals on the side of the first insulating member 5 close to the pole 31. Such a configuration allows the first insulating member 5 and the pole 31 to be better nested with each other, which can increase the torque, improve the anti-twisting effect and connection stability of the pole 31, help resist vibration and external force impact during the use of the single battery, and improve the safety and reliability of the battery single.

[0064] exist Figure 7 and Fig.13 In the embodiment shown, the dimension of the pole ear 21 in the height direction X is H1 mm, the maximum dimension of the pole base 312 in the height direction X is H2 mm, the minimum dimension of the pole base 312 in the height direction X is H3 mm, and the dimension between the electrode body 20 and the pole base 312 is H4 mm, satisfying:

[0065]

[0066] It can be understood that a portion of the pole ear 21 is passed through the through hole 310 and welded to the pole base 312, and the electrode body 20 and the pole base 312 are spaced apart. The present application limits the ratio of the dimension H1 of the pole ear 21 in the height direction X to the dimension H4 between the electrode body 20 and the pole base 312. On the one hand, it can ensure the connection stability between the pole ear 21 and the pole base 312, and on the other hand, it can ensure that the gap between the electrode body 20 and the pole base 312 is reasonably designed, which can effectively improve the space utilization and improve the energy density. At the same time, the present application sets an inclined second mating surface 301 and a first mating surface 3120 to clamp the seal 4, so that the rebound force of the seal 4 can be dispersed to the pole base 312 and the pole body 313, thereby reducing the force on the pole base 312 and further reducing the thickness of the pole base 312. The present application limits the ratio of the maximum dimension H2 of the pole base 312 in the height direction X to the minimum dimension H3 of the pole base 312 in the height direction X, thereby ensuring the structural strength of the pole 31 while reducing the space occupied by the pole base 312, thereby improving the energy density of the single battery.

[0067] It should be noted that H1 is the dimension of the gathered portion of the pole tab 21 in the height direction X, and the gathered portion is extended along the height direction X and connected to the pole base. The gathered portion can be measured.

[0068] In some embodiments, the single cell is cured by crystal glue and dissected, a vernier caliper or a two-dimensional element is used to measure H1, H2, H3, and H4, and the energy density of the single cell is calculated. The measurement results are shown in Table 1.

[0069] Table 1:

[0070]

[0071] Take a certain type of single battery as an example, its rated voltage is 3.2V, rated capacity is 88Ah, and weight is 1.6Kg. According to the energy density calculation formula: energy density = (rated voltage × rated capacity) / weight, it can be concluded that the energy density of the single battery is about 176Wh / kg. The energy density is controlled between 0.004 and 0.038, and the energy density is greater than 176Wh / kg, which can effectively improve the energy density. In Examples 14 and 15, The energy density is not between 0.004 and 0.038, and is less than 176Wh / kg, which is a low energy density.

[0072] exist Figure 4In the illustrated embodiment, the single battery includes a stopper 6, which includes a first stopper 60 and a second stopper 61, and a portion of the pole tab 21 is located between the first stopper 60 and the second stopper 61 and is respectively connected to the first stopper 60 and the second stopper 61. It is understandable that the pole tab 21 is generally composed of multiple layers of pole tabs 21, which are gathered and limited by the first stopper 60 and the second stopper 61, and the pole tab 21 is respectively connected to the first stopper 60 and the second stopper 61 by laser welding or conductive adhesive bonding, and the first stopper 60 and the second stopper 61 are respectively connected to the pole base 312 by laser welding or conductive adhesive bonding. In this way, the stopper 6 can be used to gather, support and shape the tab 21, ensuring that the tab 21 extends along the height direction X and penetrates the through hole 310, avoiding bending, wrinkling or delamination caused by the thin thickness and low rigidity of the tab 21, and causing poor electrical connection and even short circuit in the tab 21. In addition, by setting the stopper 6, the thickness of the tab 21 can be increased, the flow area can be increased, and the flow capacity of the single cell can be improved.

[0073] exist Figure 6 In the embodiment shown, the pole 31 is a positive pole 317, the pole ear 21 is a positive pole ear 210, and the positive pole ear 210 is electrically connected to the positive pole 317; the positive pole ear 210 and the positive pole 317 enclose a first closed space 7, and the inner wall of the first closed space 7 is made of aluminum. Exemplarily, the positive pole 317 is made of aluminum alloy, the positive pole ear 210 is made of aluminum, and the first closed space 7 is enclosed by aluminum.

[0074] exist Figure 6 In the illustrated embodiment, the pole 31 is a negative pole 318, the pole ear 21 is a negative pole ear 211, and the negative pole ear 211 is electrically connected to the negative pole 318; the negative pole ear 211 and the negative pole 318 enclose a second enclosed space 8, and the material of the inner wall of the second enclosed space 8 is copper. Exemplarily, the negative pole 318 is usually made of copper or aluminum, and the negative pole ear 211 is made of copper. In some embodiments, there is a situation where the electrolyte leaks into the negative pole 318. Setting the material of the inner wall of the second enclosed space 8 to copper can avoid the risk of copper-aluminum corrosion, thereby improving the safety and reliability of the single cell.

[0075] exist Figures 2 to 4 In the illustrated embodiment, the single cell includes a first insulating layer 9, which surrounds the pole ear 21 and is connected to the electrode body 20, and the positive projection of the pole base 312 along the height direction X is located in the first insulating layer 9. The distance between the electrode body 20 and the pole base 312 is small, and they are separated by the first insulating layer 9, which can effectively prevent short circuit.

[0076] exist Figure 2In the illustrated embodiment, the single cell includes a second insulating layer 10, which is located between the electrode body 20 and the shell 1 and covers the electrode body 20. The second insulating layer 10 can insulate the electrode body 20 from the shell 1, prevent short circuits, and improve the safety of the single cell.

[0077] exist Figure 7 and Fig.13 In the illustrated embodiment, the single cell includes a second insulating member 11, which is located on a side of the cover body 30 close to the electrode assembly 2, and at least a portion of the second insulating member 11 is clamped between the cover body 30 and the pole base 312. The second insulating layer 10 and the peripheral side of the second insulating member 11 are fixed by hot melting, which can improve the connection stability of the second insulating layer 10, avoid displacement, falling off and other problems of the second insulating layer 10, and ensure the insulation performance of the second insulating layer 10.

[0078] In some embodiments, the assembly of a single cell includes the following steps: folding the pole lug 21, and the limiting member 6 clamping the pole lug 21. The limiting member 6 and the pole lug 21 are laser welded or bonded with a conductive adhesive. The fixedly connected pole lug 21 and the limiting member 6 are passed through the through hole 310 and connected to the pole base 312. The pole base 312 and the limiting member 6 are laser welded or bonded with a conductive adhesive. Connecting the first insulating member 5 and the cover body 30. Connecting the cover body 30 and the shell 1. Connecting the sealing plate 315 and the pole body 313. The injection hole is sealed.

[0079] Accordingly, an embodiment of the present application provides a battery pack, including the above-mentioned single cell. The battery pack can be a single physical module including one or more single cells to provide higher voltage and capacity. When there are multiple single cells, the multiple single cells can be connected in series, in parallel or in a mixed manner.

[0080] 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.

[0081] The above is a detailed introduction to a single cell and a battery pack provided in the embodiments of the present application, and the principles and implementation methods of the present application are explained by applying specific examples. 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 solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: include: A housing having a receiving cavity; An electrode assembly is located in the accommodating cavity, and the electrode assembly includes an electrode body and an electrode ear connected to each other; A cover plate assembly having an intersecting height direction and a length direction, the cover plate assembly comprising a cover plate body and a pole, the cover plate body being connected to the shell and covering the accommodating cavity, the cover plate body having a pole hole penetrating along the height direction, the pole being inserted through the pole hole; The pole comprises a pole body and a pole base, the pole body is passed through the pole hole and connected to the pole base along the height direction, the pole base is close to the electrode assembly, and the pole base has a through hole passing through along the height direction; a part of the pole ear is passed through the through hole and fixedly connected to the pole base; A sealing member, surrounding the pole base and abutting against the cover body and the pole base; Wherein, the pole base has a first mating surface, the first mating surface is inclined relative to the height direction, and the sealing component is connected to the first mating surface.

2. The single cell according to claim 1, characterized in that: The cover body has a second mating surface, which is located in the pole hole and inclined relative to the height direction. The second mating surface and the first mating surface are arranged opposite to each other along the length direction, and the sealing member is connected to the second mating surface and the first mating surface respectively.

3. The single cell according to claim 1, characterized in that: The seal surrounds the pole body and abuts the cover body and the pole body; the pole body has a third mating surface, the third mating surface is connected to the first mating surface and is inclined relative to the height direction, and the seal is connected to the third mating surface.

4. The single cell according to claim 1, characterized in that: The single cell battery includes a first insulating member, which is located on a side of the cover body away from the electrode assembly. A portion of the first insulating member passes through the pole hole and surrounds the pole body. The first insulating member fixedly connects the pole body and the cover body; along the height direction, the first insulating member abuts against the sealing member.

5. The single cell according to claim 4, characterized in that: The cover plate body includes a first protrusion, which protrudes toward a side away from the electrode assembly and surrounds the pole hole; The first insulating member has a first groove on one side close to the electrode assembly for the first protrusion to be embedded.

6. The single cell according to claim 5, characterized in that: The first insulating member includes a clamping portion, which is located in the first groove and protrudes toward a side close to the electrode assembly. The first protrusion has a notch for the clamping portion to be embedded.

7. The single cell according to claim 4, characterized in that: The first insulating member includes a second protrusion, and the second protrusion protrudes toward a side close to the pole; A side of the pole close to the first insulating member has a second groove for the second protrusion to be embedded in.

8. The single cell according to claim 1, characterized in that: The dimension of the pole ear in the height direction is H1 mm, the maximum dimension of the pole base in the height direction is H2 mm, the minimum dimension of the pole base in the height direction is H3 mm, and the dimension between the electrode body and the pole base is H4 mm, satisfying:

9. The single cell according to claim 1, characterized in that: The single battery comprises a limiting member, the limiting member comprises a first limiting portion and a second limiting portion, and the portion of the pole tab is located between the first limiting portion and the second limiting portion and is connected to the first limiting portion and the second limiting portion respectively.

10. The single cell according to claim 1, characterized in that: The pole body has a slot body penetrating along the height direction, and the slot body is communicated with the through hole; the single battery includes a sealing plate, and the sealing plate is connected to the pole body and covers the slot body.

11. The single cell according to claim 1, characterized in that: The single battery comprises a first insulating layer surrounding the electrode lug and connected to the electrode body, and the orthographic projection of the electrode base along the height direction is located within the first insulating layer; and / or The unit battery includes a second insulating layer, which is located between the electrode body and the case and covers the electrode body.

12. A battery pack, characterized in that: The invention comprises the single cell according to any one of claims 1 to 11.

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