Single battery and battery pack

Abstract

The utility model discloses a single battery and a battery pack, the single battery has a first direction and a second direction, and the single battery comprises: a shell having a first port; the battery cell is arranged in the shell; the pole comprises a body part and a fixed part which are distributed along the first direction, and the size of the body part in the second direction is smaller than that of the fixed part; the pole is electrically connected with the battery cell; the fixed part is connected with the shell through the insulating fixed part; the insulation sealing assembly is arranged between the pole and the shell; the battery pack comprises a box body and single batteries arranged in the box body. According to the battery, the pole and the shell are fixed on the single side through the insulation fixing piece, and the pole and the shell are insulated and sealed by adopting the insulation sealing assembly, so that the size of the pole can be designed to be larger, the overcurrent area is larger, and the quick charging performance of the battery is improved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and more particularly to a single cell and a battery pack. Background Art

[0002] In existing single-cell batteries, the pole and the shell are generally sealed and fixed by riveting. The pole is in the shape of an "I", so that the insulating rubber ring is embedded between the pole and the shell to achieve insulation and sealing. However, when implementing the riveting process, if the cross-sectional area of ​​the pole is designed to be too large, the force acting on the shell will be large, which may easily cause the shell to deform due to force, resulting in damage to the workpiece. It is also easy to cause the insulating gasket in the shell to deform or crack due to force, resulting in damage to the workpiece. Therefore, the cross-sectional size of the pole of existing single-cell batteries cannot generally be designed to be very large, the weldable area between the pole and the collector plate is limited, the current capacity is limited, and the fast charging capacity of the single-cell battery is limited. Utility Model Content

[0003] The purpose of this application is to provide a single cell and a battery pack to solve the technical problem that the large force applied when riveting the pole and the shell can easily cause damage to the workpiece, resulting in the pole section being unable to be designed to be large and the current carrying capacity being limited. The technical solution is as follows:

[0004] The single cell of the embodiment of the present application has a first direction and a second direction perpendicular to each other, and the single cell includes:

[0005] A shell, wherein one end of the shell in the first direction has a first opening;

[0006] A battery cell is arranged in the housing;

[0007] The pole comprises a main body and a fixing part connected to the main body, the main body and the fixing part are distributed along a first direction, and a size of the main body in a second direction is smaller than a size of the fixing part in the second direction; the main body is passed through the first opening, and the pole is electrically connected to the battery cell;

[0008] an insulating fixing member, the fixing portion being connected to the housing via the insulating fixing member; and

[0009] The insulating sealing component is arranged between the pole and the shell.

[0010] Optionally, the insulating fixing parts are respectively embedded in the shell and the fixing part, so that the fixing part is fixedly connected to the shell.

[0011] Optionally, the fixing portion is provided with a countersunk hole, the countersunk hole penetrates the fixing portion along the first direction, and the insulating fixing piece is passed through the countersunk hole and embedded in the shell.

[0012] Optionally, the insulating sealing assembly includes an insulating gasket, at least a portion of which is disposed between the fixing portion and the shell, and the insulating fixing member passes through the insulating gasket.

[0013] Optionally, the insulating sealing assembly includes an insulating gasket and a sealant, wherein at least a portion of the insulating gasket is disposed between the fixing portion and the shell, and the sealant is sealingly disposed between the pole and the shell and is located on the periphery of the insulating gasket.

[0014] Optionally, the fixing portion is located in a accommodating cavity surrounded by the shell, the main body portion passes through the first opening to the outside of the accommodating cavity, the fixing portion is electrically connected to the battery cell, the insulating fixing piece has a first surface facing the battery cell, the fixing portion has a second surface facing the battery cell, the first surface is away from the battery cell relative to the second surface or the first surface is flush with the second surface.

[0015] Optionally, the insulating sealing assembly includes an insulating gasket, which has an inner wall in a first direction in the shell, and the first opening is arranged on the inner wall. The insulating gasket includes a main body and a first wrap-around flap portion, the main body portion is arranged between the fixed portion and the inner wall, and the first wrap-around flap portion is connected to the main body portion and is located between the fixed portion and the circumferential inner wall of the shell.

[0016] Optionally, the single cell battery also includes a first current collecting disk, which is arranged between the battery cell and the pole, and is electrically connected to the fixing part. The height H1 of the first retracted petal part in the first direction, the thickness H2 of the fixing part in the first direction, and the thickness H3 of the first current collecting disk in the first direction satisfy the following relationship: 0.5*H2≤H1≤H2+H3.

[0017] Optionally, the insulating sealing assembly includes an insulating gasket, which has an inner wall in a first direction in the shell, and the first opening is arranged on the inner wall. The insulating gasket includes a main body and a second wrap-around flap portion, the main body portion is arranged between the fixed portion and the inner wall, and the second wrap-around flap portion is connected to the main body portion and is located between the main body portion and the shell.

[0018] Optionally, the sealant is disposed between the outer side wall of the main body and the hole wall of the first opening.

[0019] Optionally, the outer side wall of the main body and / or the hole wall of the first opening is provided with a glue containing groove, and at least a part of the sealant is contained in the glue containing groove.

[0020] Optionally, an outer side wall of the main body and / or a hole wall of the first opening is provided with a glue overflow prevention groove, and the glue overflow prevention groove is located on a side of the glue containing groove away from the battery cell.

[0021] Optionally, a limiting boss is provided at one end of the shell in the first direction, the limiting boss extends along the first direction away from the shell, and the limiting boss is arranged around the circumference of the first opening.

[0022] The battery pack of the embodiment of the present application includes a box body and the above-mentioned single battery, and the single battery is arranged in the box body.

[0023] The single cell battery of the present application has at least the following beneficial effects: the single cell battery of the present application adopts a pole structure different from the "I"-shaped self-riveting pole structure of the prior art, and the pole is fixed to the shell on one side by an insulating fixing part, and an insulating sealing assembly is used to insulate and seal the pole and the shell, so that when assembling the single cell battery, there is no need to apply a large force to the shell to complete the insulation and sealing between the pole and the shell, and the insulating gasket is not subject to large stress, so that when designing the single cell battery, a pole with a larger cross-sectional size can be designed as needed to increase the current flow area, which is beneficial to improving the fast charging performance of the single cell battery.

[0024] The battery pack of the present application may include all the technical features and beneficial effects of the above-mentioned single battery, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0026] Figure 1 is a schematic diagram of an exploded structure of a single cell provided in an embodiment of the present application;

[0027] Figure 2 is a schematic diagram of a half-section structure of a single cell provided in one embodiment of the present application;

[0028] Figure 3 yes Figure 2 An enlarged schematic diagram of the structure shown at position I;

[0029] Figure 4 It is a schematic diagram of a half-section structure of a pole provided in an embodiment of the present application;

[0030] Figure 5 is a schematic diagram of a half-section structure of an insulating gasket provided in one embodiment of the present application;

[0031] Figure 6 is a schematic diagram of a half-section structure of a housing provided in one embodiment of the present application;

[0032] Figure 7 yes Figure 6 An enlarged schematic diagram of the structure shown at position II;

[0033] Figure 8 It is a schematic diagram of the three-dimensional structure of an insulating fixing member provided in one embodiment of the present application;

[0034] Fig. 9 This is a three-dimensional structural diagram of an insulating gasket provided in another embodiment of the present application.

[0035] Fig.10 is a schematic diagram of a half-section structure of an insulating gasket provided in another embodiment of the present application;

[0036] Fig.11 This is a schematic diagram of a half-section structure of a single cell provided in another embodiment of the present application.

[0037] Fig.12 yes Fig.11 An enlarged schematic diagram of the structure shown at position III;

[0038] Fig.13 is a schematic diagram of the three-dimensional structure of a housing provided in another embodiment of the present application;

[0039] Fig.14 is a schematic diagram of a half-section structure of a housing provided in another embodiment of the present application;

[0040] Fig.15 DCR internal resistance box line diagram of different structural designs provided in one embodiment of the present application;

[0041] Fig.16 This is a power curve diagram of a two-sample T test provided in an embodiment of the present application.

[0042] Figure markings: 1-shell, 11-first opening, 12-inner wall, 121-fixing hole, 13-limiting boss, 14-second opening, 2-battery cell, 3-pole, 31-main body, 32-fixing part, 321-sunk platform hole, 322-second surface, 33-groove structure, 4-insulating fixing piece, 41-first surface, 5-insulating sealing assembly, 51-insulating gasket, 511-main body, 512-first back-wrapping petal part, 513-second back-wrapping petal part, 514-through hole, 52-sealant, 6-first current collecting plate, 7-glue containing groove, 71-first glue containing groove, 72-second glue containing groove, 8-anti-glue overflow groove, 81-first anti-glue overflow groove, 82-second anti-glue overflow groove, 9-second current collecting plate, 10-cover, 101-liquid injection hole, 102-sealant, Z-first direction, X-second direction. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying 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.

[0044] In the description of this application, it should be understood that, unless otherwise clearly specified and limited, the term "and / or" herein is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " herein, unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship. 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.

[0045] The present application provides a battery pack, which includes a box and a single cell, wherein the single cell is arranged in the box. Since the specific structure of the box and the arrangement between the single cell and the box can be realized by using the existing technology and are not the focus of the present application, they will not be described in detail in this embodiment.

[0046] The single battery includes a shell 1, a battery cell 2, a pole 3, an insulating fixing 4 and an insulating sealing assembly 5. Next, a cylindrical battery is taken as an example and combined with Figures 1 to 8 The technical solution of this application is described. In order to more clearly describe the technical solution, the following definition is given: Figure 1 and Figure 2 The first direction Z and the second direction X shown in FIG. are perpendicular to each other, wherein the first direction Z corresponds to the axial direction of the single battery, and the second direction X corresponds to the radial direction of the single battery. It should be noted that: Figure 1 and Figure 2 The second direction X shown in the figure is only a schematic representation and does not mean that it is limited to this single direction. In this embodiment, the second direction X refers to any radial direction of the single battery.

[0047] The housing 1 forms a receiving cavity, and one end of the housing 1 in the first direction Z has a first opening 11 connected to the receiving cavity. The aperture of the first opening 11 is smaller than the outer diameter of the end of the housing 1 where it is located, so that the housing 1 has an inner wall 12 in the first direction Z, such as Figure 6 In other words, the first opening 11 is disposed on the inner wall 12 .

[0048] The battery cell 2 is disposed in the housing 1. Since the specific structure and arrangement of the battery cell 2 can be realized by using the existing technology and it is not the focus of the present application, it will not be described in detail in this embodiment.

[0049] The pole 3 includes a body portion 31 and a fixing portion 32 connected to the body portion 31. The body portion 31 and the fixing portion 32 are distributed along a first direction Z. The size of the body portion 31 in a second direction X is smaller than the size of the fixing portion 32 in the second direction X. That is, the cross section of the pole 3 is in a "T" shape. Figure 4 As shown. The main body 31 is inserted into the first opening 11, and the pole 3 is electrically connected to the battery cell 2. The fixing part 32 is connected to the housing 1 through the insulating fixing part 4. The insulating sealing component 5 is arranged between the pole 3 and the housing 1. In some embodiments, the area enclosed by the orthographic projection of the main body 31 on the plane where the surface of the fixing part 32 facing the main body 31 is located falls within the area enclosed by the outer periphery of the fixing part 32.

[0050] The single cell battery of the present application adopts a pole structure different from the "I"-shaped self-riveting pole structure of the prior art. The pole 3 is fixed to the shell 1 on one side by an insulating fixing member 4, and an insulating sealing assembly 5 is used to insulate and seal the pole 3 and the shell 1. Therefore, when assembling the single cell battery, it is not necessary to apply a large force to the shell 1 to complete the insulation and sealing between the pole 3 and the shell 1. When designing the single cell battery, the pole 3 with a larger cross-sectional size can be designed as needed to increase the current flow area, which is beneficial to improving the fast charging performance of the single cell battery.

[0051] Reference Figures 1 to 3 , which schematically shows a preferred embodiment, the fixing portion 32 is located in the accommodating cavity surrounded by the shell 1, and the main body 31 is arranged from the first opening 11 to the outside of the accommodating cavity. Of course, in other embodiments, the fixing portion 32 can also be arranged outside the shell 1, and the main body 31 is arranged from the first opening 11 to the accommodating cavity.

[0052] In a preferred embodiment, the insulating fixing member 4 is respectively embedded in the housing 1 and the fixing portion 32, so that the fixing portion 32 is fixedly connected to the housing 1. In a further preferred embodiment, a countersunk hole 321 is provided on the fixing portion 32, and the countersunk hole 321 penetrates the fixing portion 32 along the first direction Z. The insulating fixing member 4 is penetrated in the countersunk hole 321 and embedded in the housing 1. For example Figure 3 and Figure 6 In a preferred embodiment schematically shown in the figure, the insulating fixing part 4 is an insulating screw, and a fixing hole 121 is provided at the inner wall 12 corresponding to the countersunk hole 321, and the insulating screw is passed through the countersunk hole 321 and is threadedly connected with the corresponding countersunk hole 321. The insulating screw is made of non-conductive material, such as plastic, nylon, Teflon, etc. Teflon material is preferably used, which has good insulation and mechanical properties. In addition to the above preferred embodiments, in other embodiments, the insulating fixing part 4 is not limited to an insulating screw, and it can also be other insulating fixing parts 4 such as insulating clips.

[0053] In a further embodiment, the fixing portion 32 is electrically connected to the battery cell 2. Specifically, a first current collecting plate 6 is provided between the battery cell 2 and the pole 3, and the first current collecting plate 6 is fitted with the fixing portion 32 to achieve electrical connection. The first current collecting plate 6 and the fixing portion 32 can be fixed by penetration welding or the like to achieve electrical connection. Figures 1 to 4 As shown in the figure, a groove structure 33 is provided on the side of the main body 31 away from the fixing portion 32. The bottom of the groove structure 33 is also the welding surface. Such a design can make the thickness of the pole part at the groove structure 33 thinner, which is beneficial to reducing the welding power.

[0054] In a further preferred embodiment, the insulating fixing member 4 has a first surface 41 facing the battery core 2, such as Figure 8 As shown; the fixing portion 32 has a second surface 322 facing the battery cell 2, the first surface 41 is relatively far away from the second surface 322 of the battery cell 2 or the first surface 41 is flush with the second surface 322, that is, the insulating fixing member 4 does not protrude from the second surface 322 of the fixing portion 32, such as Figure 3 As shown, the first current collecting plate 6 can be better fitted with the fixing portion 32. In other embodiments, the insulating fixing member 4 can also be a colloid such as hot melt adhesive, and the fixing portion 32 and the housing 1 are fixedly connected by gluing.

[0055] In a further preferred embodiment, the insulating sealing assembly 5 may include an insulating gasket 51. The insulating gasket 51 includes but is not limited to various types of high temperature and corrosion resistant materials, such as high temperature resistant silicone, high temperature resistant POM, etc. At least part of the insulating gasket 51 is arranged between the fixing portion 32 and the shell 1. The single cell design of the present application can prevent the insulating gasket 51 from being subjected to large stress, and will not cause the insulating gasket 51 to deform or crack due to stress and cause damage to the workpiece. In this preferred embodiment, the insulating fixing member 4 can be arranged to pass through the insulating gasket 51. For example Figure 3 and Figure 5 In a preferred embodiment schematically shown in the figure, the insulating gasket 51 includes a main body portion 511 and a first wraparound petal portion 512. The main body portion 511 is arranged between the fixing portion 32 and the inner wall 12, and the fixing portion 32 is provided with an inner hole. The first wraparound petal portion 512 is connected to the main body portion 511 near the outer edge of the main body portion 511, and is located between the fixing portion 32 and the circumferential inner wall 12 of the shell 1. The first wraparound petal portion 512 can better insulate the edge of the fixing portion 32 from the shell 1. In another preferred embodiment, the insulating gasket 51 may further include a second wraparound petal portion 513, which is connected to the main body portion 511 near the inner edge of the main body portion 511, and is located between the main body portion 31 and the shell 1, as shown in FIG. Figures 9 to 12 The second wrapping petal portion 513 can provide better insulation between the main body portion 31 and the housing 1 .

[0056] The insulating fixture 4 passes through the main body 511. Specifically, through holes 514 are respectively provided at locations corresponding to the countersunk holes 321 on the main body 511, and the insulating fixture 4 is fixedly connected to the shell 1 after passing through the corresponding through holes 514. Preferably, the through holes 514 are evenly distributed around the inner hole of the insulating fixture 4. The number of through holes 514 is not limited and can be set according to design requirements. Further preferably, the aperture of the through hole 514 is slightly larger than the outer diameter of the insulating fixture 4, so that the insulating fixture 4 passes through the insulating gasket 51 in a clearance fit manner, thereby avoiding damage to the insulating gasket 51 during assembly. Of course, in other embodiments, the insulating gasket 51 may also include only the main body 511, or only include the main body 511 and the first back-wrapped petal portion 512, or only include the main body 511 and the second back-wrapped petal portion 513; the insulating fixture 4 may also not pass through the insulating gasket 51, that is, the main body 511 does not extend to the countersunk hole 321, for example Figure 3 Taking the structure shown in as an example, the inner edge of the main body 511 may also only extend to the outer side of the insulating fixing member 4.

[0057] In such Figure 3 In the preferred embodiment in which the insulating gasket 51 is provided with the first back-wrapped petal portion 512, it is further preferred that the height H1 of the first back-wrapped petal portion 512 in the first direction Z, the thickness H2 of the fixing portion 32 in the first direction Z, and the thickness H3 of the first collecting plate 6 in the first direction Z satisfy the following relationship: 0.5*H2≤H1≤H2+H3. It can be understood that when the relationship of 0.5*H2≤H1≤H2+H3 is satisfied, better insulation between the fixing portion 32 and the housing 1 can be ensured, and the product yield can be improved. Among them, H1 can be any value of 0.5*H2, 0.6*H2, 0.7*H2, 0.8*H2, 0.9*H2, H2, H2+H3, or a range between any two values.

[0058] In a further preferred embodiment, the insulating sealing assembly 5 may further include a sealant 52, which is sealed between the pole 3 and the housing 1 and is located outside the insulating gasket 51. The sealant 52 is preferably a bottom filling glue, which has strong fluidity, can better fit the contact surface, and has excellent sealing performance. At the same time, this type of glue also has quick drying properties, which can improve manufacturing efficiency. Figure 2 and Figure 3 In a preferred embodiment schematically shown in FIG. 1 , there is a gap between the hole wall of the first opening 11 and the outer wall of the main body 31 of the pole 3, and there is a gap between the inner edge of the main body 511 of the insulating gasket 51 and the outer wall of the main body 31 of the pole 3, so that an accommodation space is formed around the insulating gasket 51. The sealant 52 is filled in the accommodation space to insulate and seal the housing 1, the pole 3 and the insulating gasket 51. Figure 3In the preferred embodiment shown, the inner hole diameter of the insulating gasket 51 is preferably larger than the diameter of the first through opening 11, so that the radial cross-section of the accommodating space is "L"-shaped, and the sealant 52 can form a corner structure after being formed, thereby improving the sealing performance of the sealant 52. Of course, in other embodiments, the inner hole diameter of the insulating gasket 51 can also be equal to or smaller than the diameter of the first through opening 11.

[0059] and Fig.11 and Fig.12 The insulating gasket 51 shown is provided with a second wrapping flap 513 and in a preferred embodiment where the outer periphery of the insulating gasket 51 is sealed with a sealant 52, the second wrapping flap 513 can not only provide better insulation between the main body 31 and the shell 1 but also reduce the sealant 52, thereby saving costs. Fig.13 and Fig.14 Another preferred solution is also schematically shown in the figure, in which a limiting boss 13 is provided at one end of the housing 1 in the first direction Z, the limiting boss 13 extends in the first direction Z in a direction away from the housing 1, and the limiting boss 13 is arranged around the circumference of the first opening 11, that is, the limiting boss 13 is in the shape of a ring-shaped protrusion. The space between the limiting boss 13 and the outer wall of the main body 31 of the pole 3 can be used to inject the sealant 52, and the limiting boss 13 can play a reinforcing role, which can ensure the strength of the end wall of the housing 1, so that the end wall of the housing 1 does not need to be designed to be too thick, saving the internal space of the housing 1.

[0060] In a further preferred embodiment, the outer wall of the main body 31 and / or the hole wall of the first opening 11 is provided with a glue containing groove 7, and at least part of the sealant 52 is contained in the glue containing groove 7. Figure 3 , Figure 4 , Figure 7 , Fig.11 or Fig.12 In the preferred embodiment shown in , a first glue containing groove 71 is provided on the outer side wall of the main body 31 , and a second glue containing groove 72 is provided on the hole wall of the first through opening 11 .

[0061] The width W1 of the first glue-containing groove 71 in the first direction Z satisfies 0.5mm≤W1≤1.0mm. It is understandable that when 0.5mm≤W1≤1.0mm is satisfied, it can be ensured that the sealant 52 can penetrate into the first glue-containing groove 71 more smoothly, and no sealing failure will be caused. W1 can be any value of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0mm or a range between any two values. The depth S1 of the first glue-containing groove 71 in the second direction X satisfies 0.5mm≤S1≤1.0mm. It is understandable that when 0.5mm≤S1≤1.0mm is satisfied, the sealing effect of the sealant 52 can be guaranteed. S1 can be any value of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0mm or a range between any two values.

[0062] The width W2 of the second glue-containing groove 72 in the first direction Z satisfies 0.5mm≤W2≤1.0mm. It is understandable that when 0.5mm≤W2≤1.0mm is satisfied, it can be ensured that the sealant 52 can penetrate into the second glue-containing groove 72 more smoothly, and no sealing failure will be caused. W2 can be any value of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0mm or a range between any two values. The depth S2 of the second glue-containing groove 72 in the second direction X satisfies 0.5mm≤S2≤1.0mm. It is understandable that when 0.5mm≤S2≤1.0mm is satisfied, the sealing effect of the sealant 52 can be guaranteed. S2 can be any value of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0mm or a range between any two values.

[0063] It should be noted that the first glue-containing groove 71 can be an annular groove extending continuously along the circumferential direction of the outer wall of the main body 31, and its number is not limited to one, and it can also be a plurality of grooves distributed at intervals along the first direction Z; the first glue-containing groove 71 can also be a groove segment extending along the circumferential direction of the main body 31, and its number is also not limited to one, for example, it can include one or more groups of groove segments, and the multiple groove segments in each group are distributed at intervals along the circumferential direction of the main body 31, and the multiple groups of groove segments are distributed at intervals along the first direction Z. The groove segments in adjacent groups can be arranged one by one or staggered. The arrangement of the second glue-containing groove 72 on the hole wall of the first through-port 11 can refer to the arrangement of the first glue-containing groove 71 on the outer wall of the main body 31, which will not be repeated here. The above-mentioned design of the glue-containing groove 7 can effectively increase the fitting area between the sealant 52 and the shell 1 or the pole 3 when sealing, and at the same time, it can also form a corner after the sealant 52 is formed, thereby effectively improving the sealing performance of the sealant 52. The radial cross-sectional shape of the adhesive groove 7 is not limited, and can be a polygon such as a triangle or a quadrilateral, or can be other shapes such as an arc. In addition to the above preferred embodiments, in other embodiments, the adhesive groove 7 can be provided only on the outer wall of the main body 31, or only on the hole wall of the first opening 11.

[0064] In a further preferred embodiment, the outer wall of the main body 31 and / or the hole wall of the first opening 11 is provided with an anti-overflowing glue groove 8, and the anti-overflowing glue groove 8 is located on the side of the glue containing groove 7 away from the battery cell 2. Figure 3 , Figure 4 , Figure 7 , Fig.11 or Fig.12 In the preferred embodiment shown in FIG, a first anti-overflow glue groove 81 is provided on the outer wall of the main body 31, and a second glue containing groove 72 is provided on the hole wall of the first opening 11. Figure 3The technical solution is explained with reference to the up, down, left, and right directions in the figure: the lower groove wall of the first anti-overflow glue groove 81 is lower than the upper end wall of the shell 1, and the second anti-overflow glue groove 82 passes through the upper end wall of the shell 1.

[0065] The width W3 of the first anti-overflow glue groove 81 in the first direction Z satisfies 0.5 mm ≤ W3 ≤ 1.0 mm. It is understandable that when 0.5 mm ≤ W3 ≤ 1.0 mm is satisfied, the risk of glue overflow can be reduced during glue application. W3 can be any value of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 mm or a range between any two values.

[0066] The width W4 of the second anti-overflow glue groove 82 in the first direction Z satisfies 0.5 mm ≤ W4 ≤ 1.0 mm. It is understood that when 0.5 mm ≤ W4 ≤ 1.0 mm is satisfied, the risk of glue overflow can be reduced during glue application. W4 can be any value of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 mm or a range between any two values.

[0067] It should be noted that the first anti-overflow glue groove 81 can be an annular groove extending continuously along the circumference of the outer wall of the main body 31, or a groove section extending along the circumferential direction of the main body 31, and its number is not limited to one, for example, it can include multiple groove sections distributed at intervals along the circumferential direction of the main body 31. The second anti-overflow glue groove 82 can be an annular groove extending continuously along the circumferential direction of the hole wall of the first opening 11, or it can be a groove section extending along the circumferential direction of the hole wall of the first opening 11, and its number is not limited to one, for example, it can include multiple groove sections distributed at intervals along the circumferential direction of the hole wall of the first opening 11. The multiple groove sections can all pass through the upper end wall of the shell 1, or only some of the groove sections can pass through the upper end wall of the shell 1. The above-mentioned anti-overflow glue groove 8 design can prevent glue overflow when injecting the sealant 52. Of course, in other embodiments, the anti-overflow glue groove 8 can be set only on the outer wall of the main body 31, or the anti-overflow glue groove 8 can be set only on the hole wall of the first opening 11.

[0068] In an advanced embodiment, the single cell further comprises a second current collecting plate 9 and a cover 10, such as Figure 1 As shown. The second collecting plate 9 is electrically connected to the battery cell 2. A second opening 14 is provided at the other end of the shell 1 in the first direction Z, and the cover 10 is sealed at the second opening 14. The second collecting plate 9 is provided between the battery cell 2 and the cover 10, and the second collecting plate 9 is electrically connected to the cover 10. The cover 10 is provided with an injection hole 101, which can be used to inject electrolyte into the shell 1. The injection hole 101 is sealed by a sealing member 102 such as a sealing pin. Since this part of the content is the prior art and is not the focus of protection of this application, it will not be described in detail in this embodiment. In addition, it should be noted that in Figure 1 and Figure 2In the preferred embodiment shown, the pole 3 is a positive pole of a single cell, the first current collecting plate 6 is also a positive current collecting plate, and the second current collecting plate 9 is also a negative current collecting plate. Of course, in a specific implementation, the pole 3 is not limited to the positive pole of a single cell, and it can also be a negative pole.

[0069] Next, Figure 1 The assembly process of the single cell in the embodiment shown is illustrated by way of example:

[0070] S1, coaxially assemble the insulating gasket 51 from the second opening 14 of the housing 1 into the accommodating cavity of the housing 1, and make the insulating gasket 51 close to the inner wall 12 of the housing 1, and make the through hole 514 on the insulating gasket 51 correspond to the fixing hole 121 on the inner wall 12;

[0071] S2, coaxially assemble the pole 3 from the second opening 14 of the housing 1 into the accommodating cavity of the housing 1, and make the body 31 of the pole 3 pass through the inner hole of the insulating gasket 51 and the first opening 11 in sequence, the fixing portion 32 of the pole 3 is tightly attached to the insulating gasket 51, and the countersunk hole 321 on the pole 3 corresponds to the through hole 514;

[0072] S3, passing the insulating screw through the countersunk hole 321 and the through hole 514 in sequence and locking it with the thread of the fixing hole 121, so as to complete the fixation between the pole 3, the insulating gasket 51 and the housing 1;

[0073] S4, using a glue gun to dispense glue into the accommodation space formed between the pole 3 and the housing 1;

[0074] S5, after the dispensing is completed, the sealant 52 is quickly baked to solidify and complete the insulation and sealing between the pole 3 and the housing 1;

[0075] S6, welding the first current collecting plate 6 and the second current collecting plate 9 to the battery cell 2 respectively, and then assembling the welded battery cell 2 into the accommodating cavity of the housing 1 through the second opening 14;

[0076] S7, performing penetration welding on the welding area of ​​the first current collecting plate 6 and the pole 3 to complete the electrical connection;

[0077] S8, performing penetration welding on the second current collecting plate 9 and the cover 10, and then performing sealing welding on the cover 10 and the shell 1 to complete electrical connection and sealing;

[0078] S9, the assembled single battery is baked, liquid-filled, and formed, and then the sealing pins are welded to complete the battery sealing.

[0079] According to the test, taking the 4695 cylindrical battery as an example, the welding area between the positive electrode and the collector plate in the traditional 4695 cylindrical battery with riveted electrode is generally designed to be less than 19.63mm 2(circular welding area with a diameter less than 5mm). If the traditional positive and negative electrode penetration welding process is used, the DCR internal resistance limit can be 2.0 milliohms, and the overcurrent capacity is limited, which will limit the fast charging performance of the battery; while the 4695 cylindrical battery using the structural design of the present application, the welding area between the pole 3 and the first collector 6 can reach 452.16mm 2 (Circular welding area with a diameter of 24mm), which is much larger than the limit welding area of ​​the traditional pole riveted 4695 cylindrical battery. The flow area is greatly increased, which is beneficial to improving the fast charging performance of the single battery.

[0080] Next, we designed and carried out a current capacity verification test using the 4695 cylindrical battery with the structural design of the present application and the traditional positive pole riveted 4695 battery as comparison items, as follows:

[0081] Test items:

[0082]

[0083] Test conditions:

[0084] 1. Design of incoming battery cells

[0085] Tab Forming Method Cell Design Battery cell total height tolerance design Cut and stack Two-end ear ±0.2mm

[0086] 2. The welding process uniformly adopts the traditional cylindrical battery negative electrode penetration welding structure, and the use of the laser is as follows:

[0087]

[0088] 3. Checklist

[0089] Serial number project Specifications / Requirements Detection Methods Remark 1 DCR internal resistance \ DCR internal resistance test 3C, 10s

[0090] Analysis of test results:

[0091] The DCR internal resistance of the 4695 cylindrical battery using the structural design of the present application and the traditional positive pole riveted 4695 cylindrical battery were tested respectively. The DCR internal resistance box line diagrams of the two are as follows: Fig.15 It can be seen that the DCR internal resistance of the 4695 cylindrical battery using the structural design of the present application is 19.5% lower than that of the traditional positive pole riveted 4695 cylindrical battery, and the current capacity is significantly improved.

[0092] Hypothesis testing and sample size calculation:

[0093] 1. Perform a two-sample T hypothesis test on the defective rate of the above two different structures of 4695 cylindrical batteries:

[0094] Original hypothesis: There is no significant difference in DCR internal resistance between the 4695 cylindrical battery using the structural design of the present application and the traditional positive electrode column riveted 4695 cylindrical battery;

[0095] Alternative hypothesis: The DCR internal resistance of the 4695-type cylindrical battery using the structural design of the present application is less than the DCR internal resistance of the traditional positive electrode column riveted 4695-type cylindrical battery.

[0096] 2. Hypothesis test results:

[0097]

[0098] Difference = mu (4695 cylindrical battery using the structural design of the present application) - mu (4695 cylindrical battery with traditional positive electrode column riveted);

[0099] Difference estimate: -0.399539;

[0100] 95% upper confidence limit of the difference: -0.397952;

[0101] T test for difference = 0 (vs. <): T value = -414.18, P value = 0.000, degrees of freedom = 2106;

[0102] Both use a pooled standard deviation = 0.0221;

[0103] If P value is less than 0.05, the result is significant and the alternative hypothesis is accepted.

[0104] 3. Sample size calculation:

[0105] The power curve of the two-sample T test is as follows Fig.16 As shown, it can be seen that the sample size power value of 1000 reaches 100%, and the sample size meets the judgment.

[0106] Next, examples 1 to 12 are provided. Examples 1 to 12 are all based on Figures 1 to 3 The cylindrical battery shown in the figure is provided with a first back-wrapped petal portion 512. The difference between the cylindrical batteries of various embodiments is that the height H1 of the first back-wrapped petal portion 512 in the first direction Z varies, and other technical features remain the same. Taking the thickness H2 of the fixing portion 32 in the first direction Z as 1 mm and the thickness H3 of the first current collecting plate 6 in the first direction Z as 0.2 mm as an example, the yield rate of the cylindrical batteries of various embodiments is tested respectively. The specific test process is: drop and vibration test. The test results are shown in Table 1.

[0107] Table 1

[0108] <![CDATA[H1 / mm]]> <![CDATA[H2 / mm]]> <![CDATA[H3 / mm]]> Yield / % Example 1 0.3 1 0.2 99.01％ Example 2 0.4 1 0.2 99.24％ Example 3 0.5 1 0.2 99.89％ Example 4 0.6 1 0.2 99.83％ Example 5 0.7 1 0.2 99.94％ Example 6 0.8 1 0.2 99.93％ Example 7 0.9 1 0.2 99.99％ Example 8 1.0 1 0.2 99.85％ Example 9 1.1 1 0.2 99.89％ Example 10 1.2 1 0.2 99.94％ Embodiment 11 1.3 1 0.2 99.54％ Example 12 1.4 1 0.2 99.44％

[0109] In Table 1, the cylindrical batteries of Examples 1 and 2 satisfy the relationship of H1<0.5*H2, the cylindrical batteries of Examples 3-10 satisfy the relationship of 0.5*H2≤H1≤H2+H3, and Examples 11 and 12 satisfy the relationship of H1>H2+H3. As can be seen from Table 1, the yield rate of the cylindrical batteries of Examples 1-12 all reached more than 99%, which all met the production requirements, especially the cylindrical batteries of Examples 3-10, which had the best yield rate.

[0110] The above are only some implementation methods of the embodiments of the present application, and do not constitute any form of limitation on the application. The protection scope of the embodiments of the present application is not limited to this. Any simple modifications, equivalent changes and modifications that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the embodiments of the present application should be covered within the protection scope of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: The single cell has a first direction (Z) and a second direction (X) perpendicular to each other, and the single cell comprises: A shell (1), wherein one end of the shell (1) in the first direction (Z) has a first opening (11); A battery cell (2) is arranged in the housing (1); A pole (3), the pole (3) comprising a main body (31) and a fixing part (32) connected to the main body (31), the main body (31) and the fixing part (32) being distributed along the first direction (Z), the size of the main body (31) in the second direction (X) being smaller than the size of the fixing part (32) in the second direction (X); the main body (31) is passed through the first opening (11), and the pole (3) is electrically connected to the battery core (2); an insulating fixing member (4), wherein the fixing portion (32) is connected to the housing (1) via the insulating fixing member (4); and An insulating sealing assembly (5) is arranged between the pole (3) and the housing (1).

2. The single cell according to claim 1, characterized in that: The insulating fixing member (4) is respectively embedded in the shell (1) and the fixing portion (32), so that the fixing portion (32) is fixedly connected to the shell (1).

3. The single cell according to claim 2, characterized in that: The fixing portion (32) is provided with a countersunk hole (321), the countersunk hole (321) passes through the fixing portion (32) along the first direction (Z), and the insulating fixing piece (4) is passed through the countersunk hole (321) and embedded in the shell (1).

4. The single cell according to claim 2, characterized in that: The insulating sealing assembly (5) comprises an insulating gasket (51), at least a portion of which is arranged between the fixing portion (32) and the housing (1), and the insulating fixing member (4) passes through the insulating gasket (51).

5. The single cell according to claim 1, characterized in that: The insulating sealing assembly (5) comprises an insulating gasket (51) and a sealant (52); at least a portion of the insulating gasket (51) is arranged between the fixing portion (32) and the shell (1); the sealant (52) is sealingly arranged between the pole (3) and the shell (1) and is located on the periphery of the insulating gasket (51).

6. The single cell according to claim 2, characterized in that: The fixing portion (32) is located in a receiving cavity surrounded by the shell (1); the main body (31) is extended from the first opening (11) to the outside of the receiving cavity; the fixing portion (32) is electrically connected to the battery core (2); the insulating fixing member (4) has a first surface (41) facing the battery core (2); the fixing portion (32) has a second surface (322) facing the battery core (2); the first surface (41) is away from the battery core (2) relative to the second surface (322) or the first surface (41) is flush with the second surface (322).

7. The single cell according to claim 1, characterized in that: The insulating sealing assembly (5) comprises an insulating gasket (51), the shell (1) has an inner wall (12) in the first direction (Z), the first opening (11) is arranged on the inner wall (12), the insulating gasket (51) comprises a main body (511) and a first wraparound flap (512), the main body (511) is arranged between the fixing part (32) and the inner wall (12), the first wraparound flap (512) is connected to the main body (511) and is located between the fixing part (32) and the circumferential inner wall of the shell (1).

8. The single cell according to claim 7, characterized in that: The single battery further comprises a first current collecting disk (6), the first current collecting disk (6) being arranged between the battery cell (2) and the pole (3), the first current collecting disk (6) being electrically connected to the fixing portion (32), a height H1 of the first wrapping petal portion (512) in the first direction (Z), a thickness H2 of the fixing portion (32) in the first direction (Z), and a thickness H3 of the first current collecting disk (6) in the first direction (Z) satisfying the following relationship: 0.5*H2≤H1≤H2+H3.

9. The single cell according to claim 1, characterized in that: The insulating sealing assembly (5) comprises an insulating gasket (51), the shell (1) has an inner wall (12) in the first direction (Z), the first opening (11) is arranged on the inner wall (12), the insulating gasket (51) comprises a main body (511) and a second wraparound flap (513), the main body (511) is arranged between the fixing portion (32) and the inner wall (12), the second wraparound flap (513) is connected to the main body (511) and is located between the main body (31) and the shell (1).

10. The single cell according to claim 5, characterized in that: The sealant (52) is arranged between the outer wall of the main body (31) and the hole wall of the first opening (11).

11. The single cell according to claim 10, characterized in that: The outer side wall of the main body (31) and / or the hole wall of the first opening (11) is provided with a glue containing groove (7), and at least a part of the sealing glue (52) is contained in the glue containing groove (7).

12. The single cell according to claim 11, characterized in that: An anti-overflow glue groove (8) is provided on the outer side wall of the main body (31) and / or the hole wall of the first opening (11), and the anti-overflow glue groove (8) is located on a side of the glue containing groove (7) away from the battery core (2).

13. The single cell according to claim 1, characterized in that: A limiting boss (13) is provided at one end of the shell (1) in the first direction (Z), the limiting boss (13) extending in the first direction (Z) in a direction away from the shell (1), and the limiting boss (13) is arranged along the circumference of the first opening (11).

14. A battery pack, characterized in that: The invention comprises a box body and a single cell according to any one of claims 1 to 13, wherein the single cell is arranged in the box body.

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