Battery cell structure and battery

Abstract

The embodiment of the invention provides a battery cell structure and a battery, and relates to the technical field of batteries. The battery cell structure comprises a shell main body and a top cover assembly, wherein the top cover assembly comprises a shell cover, a pole, a sealing adhesive film and a connecting piece; the connecting piece is connected with the shell cover, the pole is located in the opening of the shell cover, the sealing adhesive film is bonded between the pole and the connecting piece, and the projection of the shell cover does not coincide with the projection of the pole in the height direction of the battery cell structure, so that the thickness of the top cover assembly located at the connecting part can be reduced, and the height space of the battery occupied by the top cover assembly can be reduced; the capacity of the battery can be improved, and the energy density of the battery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery core structure and a battery. Background Art

[0002] With the development of electronic products, the demand for battery capacity for electrical devices such as Bluetooth headsets and electronic bracelets is increasing.

[0003] In the related art, a cylindrical battery includes a shell body and a top cover assembly, the top cover assembly includes a shell cover, a pole and a sealing film, the shell cover is welded to the top of the shell body, and the sealing film is bonded between the shell cover and the pole in the height direction of the battery.

[0004] However, the thickness of the top cover assembly at the connection portion is relatively thick, resulting in low energy density of the battery. Summary of the invention

[0005] The embodiments of the present invention provide a cell structure and a battery to solve the problem that the thickness of the top cover assembly at the connection part is relatively thick, resulting in low energy density of the battery.

[0006] In a first aspect, an embodiment of the present invention provides a battery cell structure, including:

[0007] Shell body;

[0008] A top cover assembly, the top cover assembly comprising a shell cover, a pole, a sealing film and a connector;

[0009] The shell cover is connected to the shell body, the shell cover is provided with an opening, the connecting piece is connected to the shell cover, the pole is located in the opening of the shell cover, and the sealing film is bonded between the pole and the connecting piece;

[0010] In the height direction of the battery cell structure, the projection of the shell cover does not overlap with the projection of the pole.

[0011] In a possible implementation, the pole includes a pole body and a boss, the pole body is connected to an edge of the boss, the pole body is located in an opening of the shell cover, and the sealing film is bonded between the pole body and the connector.

[0012] In a possible implementation manner, in the height direction of the battery core structure, the thickness of the connector is less than the thickness of the shell cover; and / or,

[0013] In the height direction of the battery core structure, the thickness of the pole body is less than the thickness of the boss; and / or,

[0014] In the height direction of the battery core structure, the thickness of the connecting member is smaller than the thickness of the pole body.

[0015] In a possible implementation, in the height direction of the battery cell structure, the sum of the thickness of the connector, the sealing film and the shell cover is less than the thickness of the pole.

[0016] In a possible embodiment, it also includes a pole core, which is arranged inside the shell body, the connecting member is located on the side of the shell cover facing the pole core, the positive ear of the pole core is welded to the boss of the pole column, and a first insulating member is arranged between the positive ear and the connecting member.

[0017] In a possible implementation manner, in the height direction of the battery core structure, the top surface of the connecting member is located on a side of the bottom surface of the pole facing away from the pole core.

[0018] In a possible implementation, it further includes a pole core, which is arranged inside the shell body, the connecting piece is located on the side of the shell cover away from the pole core, the positive pole ear of the pole core is welded to the pole column, and the positive pole ear and the boss are arranged opposite to each other.

[0019] In a possible implementation manner, in the radial direction of the pole, there is a gap between the connecting member and the boss.

[0020] In a possible implementation manner, in the height direction of the battery core structure, the projection of the connecting member covers the side wall of the shell body.

[0021] In a possible implementation manner, in the axial direction of the pole, the boss includes a first end and a second end, and the first end is flush with the pole body;

[0022] The shell body is provided with a bottom wall and a side wall, the side wall is connected to the bottom wall, and the bottom wall and the side wall form a cavity.

[0023] In a possible implementation manner, when the first end of the boss faces the cavity, the outer diameter of the shell cover is equal to the inner diameter of the cavity; or,

[0024] The second end of the boss faces the cavity, and the outer diameter of the shell cover is greater than the inner diameter of the cavity.

[0025] In a possible implementation manner, the diameter of the boss is 1 mm to 5 mm; and / or,

[0026] In the height direction of the battery core structure, the thickness of the boss is 0.1 mm to 0.5 mm; and / or,

[0027] The shell cover has a thickness of 0.1 mm to 0.3 mm, and is a stainless steel cover; and / or,

[0028] The thickness of the connecting piece is 0.01 mm to 0.08 mm, and the connecting piece is a nickel sheet or a stainless steel sheet with a nickel plating on the surface; and / or,

[0029] The thickness of the connecting portion of the top cover assembly is 0.2 mm to 0.3 mm; and / or,

[0030] The thickness of the adhesive portion of the sealant film is 0.02 mm to 0.06 mm; and / or,

[0031] The maximum thickness of the pole is 0.1 mm to 0.2 mm.

[0032] In a possible implementation manner, in the height direction of the battery cell structure, a projection of a weld mark between the connector and the shell cover does not overlap with a projection of a weld mark between the shell cover and the shell body.

[0033] In a possible implementation, the sealant film comprises an overflow portion, an adhesive portion and an inner overflow portion, wherein in a radial direction of the sealant film, the overflow portion is connected to an outer edge of the adhesive portion, and the inner overflow portion is connected to an inner edge of the adhesive portion; and / or,

[0034] The thickness of the overflow portion and the thickness of the inner overflow portion are both greater than the thickness of the bonding portion.

[0035] In a possible implementation, it further includes a sealing cover, the boss is provided with a liquid injection hole, the liquid injection hole passes through the boss, the sealing cover is connected to the boss, and the sealing cover blocks the liquid injection hole; and / or,

[0036] The axis of the injection hole coincides with the axis of the pole; and / or,

[0037] The diameter of the injection hole is 0.6 mm to 2 mm.

[0038] In a possible implementation, it further includes a positive electrode connecting sheet;

[0039] In the height direction of the battery cell structure, the positive pin of the positive connecting piece is located on the side of the pole away from the shell body; or, in the radial direction of the pole, the positive pin of the positive connecting piece is located on one side of the side wall of the shell body.

[0040] In a possible implementation manner, the sealing cover is a sealing sheet, and the thickness of the sealing sheet is 0.05 mm to 0.15 mm; and / or,

[0041] The positive electrode connecting sheet is welded to the electrode column, and in the height direction of the battery core structure, the projection of the welding area of ​​the positive electrode connecting sheet does not overlap with the projection of the sealing sheet; and / or,

[0042] The projection of the welding area of ​​the positive electrode connecting sheet does not overlap with the projection of the sealing film.

[0043] In a possible implementation manner, the sealing cover includes a sealing sheet and a limiting platform, wherein the limiting platform is disposed on the sealing sheet, the limiting platform faces the cavity of the shell body, and the limiting platform is inserted into the liquid injection hole;

[0044] The positive electrode connecting sheet is welded to the sealing sheet.

[0045] In a possible embodiment, it also includes a negative electrode connecting plate, which is welded to the shell cover or the connecting piece, the negative electrode pin of the negative electrode connecting plate is located on the side of the pole away from the shell body, the projection of the welding area of ​​the negative electrode connecting plate does not overlap with the projection of the sealing film, and a second insulating member is arranged between the positive electrode connecting plate and the connecting piece.

[0046] In a possible implementation manner, a projection of the welding area of ​​the negative electrode connecting sheet does not overlap with a projection of the sealing film.

[0047] In a possible implementation manner, a negative electrode connecting plate is further included, and the negative electrode connecting plate is welded to the bottom wall of the shell body.

[0048] In a possible implementation manner, the thickness of the welding region of the negative electrode connecting sheet is smaller than the thickness of other regions of the negative electrode connecting sheet.

[0049] In a second aspect, an embodiment of the present invention provides a battery, comprising the battery cell structure as described above.

[0050] In the cell structure and battery provided by the embodiments of the present invention, a top cover assembly is provided with a connector, the connector is connected to the shell cover, the pole is located in the opening of the shell cover, the sealing film is bonded between the pole and the connector, and in the height direction of the cell structure, the projection of the shell cover does not overlap with the projection of the pole, that is, the shell cover and the pole are arranged roughly horizontally, thereby avoiding the excessive thickness of the overall top cover assembly caused by the overlapping projections of the shell cover and the pole, thereby reducing the thickness of the top cover assembly at the connection part, that is, the thickness of the top cover assembly at the part where the pole, the sealing film, the shell cover and the connector are connected can be reduced, thereby reducing the height space occupied by the top cover assembly in the battery, and can increase the capacity of the battery, and improve the energy density of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0052] Figure 1 A schematic diagram of a battery cell structure provided in Embodiment 1 of the present invention;

[0053] Figure 2 for Figure 1 A schematic cross-sectional view of a cell structure after removing the positive electrode connecting sheet and the negative electrode connecting sheet;

[0054] Figure 3 A schematic cross-sectional view of a top cover assembly provided in Embodiment 1 of the present invention;

[0055] Figure 4 for Figure 3 An exploded schematic diagram of a top cover assembly;

[0056] Figure 5 for Figure 3 A schematic diagram of the structure of the sealing film;

[0057] Figure 6 for Figure 1 A schematic cross-sectional view of a battery cell structure after removing the pole core and the first insulating member;

[0058] Figure 7 for Figure 3 Schematic diagram of the structure of the pole;

[0059] Figure 8 for Figure 1 A schematic top view of the cell structure in FIG.

[0060] Fig. 9 A schematic diagram of the connection between the housing body, the top cover assembly and the sealing cover provided in the second embodiment of the present invention;

[0061] Fig.10 A schematic diagram of a battery cell structure provided in Embodiment 3 of the present invention;

[0062] Fig.11 for Fig.10 A schematic cross-sectional view of the cell structure after removing the pole core;

[0063] Fig.12 for Fig.10 A schematic diagram of the structure of the sealing cover;

[0064] Fig.13 A schematic diagram of a battery cell structure provided in Embodiment 4 of the present invention;

[0065] Fig.14 for Fig.13 Schematic diagram of the top view of the battery cell structure.

[0066] Description of reference numerals:

[0067] 10-housing body; 101-bottom wall;

[0068] 102-side wall; 20-shell cover;

[0069] 201-opening; 30-pole;

[0070] 31-pole body; 32-boss;

[0071] 321-first end; 322-second end;

[0072] 323- injection hole; 40- connecting piece;

[0073] 50-sealant film; 501-overflow part;

[0074] 502-bonding portion; 503-inner overflow portion;

[0075] 60-pole core; 601-positive pole ear;

[0076] 70-sealing cover; 71-sealing sheet;

[0077] 72-limiting platform; 80-positive electrode connecting piece;

[0078] 801-positive electrode pin; 90-negative electrode connecting piece;

[0079] 901-negative electrode pin; 91-first insulating member;

[0080] 92- Second insulating member. DETAILED DESCRIPTION

[0081] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0082] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0083] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0084] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0085] In the above description, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0086] In the related art, the thickness of the top cover assembly at the connection part is relatively thick, resulting in low energy density of the battery. The inventors have found that the reason for this problem is that in the height direction of the battery, the sealing film is bonded between the shell cover and the pole, and the thickness of the top cover assembly at the connection part is the thickness of the top cover assembly at the connection part where the pole, the sealing film and the shell cover are connected. The thickness of the connection part is relatively thick, which makes the top cover assembly occupy a large height space of the battery, reduces the capacity of the battery, and leads to low energy density of the battery.

[0087] In order to solve the above problems, the battery cell structure and battery provided in the embodiments of the present invention are connected to the shell cover through a connecting piece, and the sealing film is bonded between the pole and the connecting piece. In the height direction of the battery cell structure, the projection of the shell cover does not overlap with the projection of the pole. Compared with the thickness of the top cover assembly in the related art where the pole, the sealing film and the shell cover are connected, the thickness of the top cover assembly in the part where the pole, the sealing film, the shell cover and the connecting piece are connected is smaller, which can reduce the height space occupied by the top cover assembly of the battery, thereby increasing the capacity of the battery and further increasing the energy density of the battery.

[0088] The cell structure and the battery provided by the embodiments of the present invention are described in detail below in conjunction with specific embodiments.

[0089] Embodiment 1

[0090] See also Figure 1 As shown, an embodiment of the present invention provides a battery cell structure, which is applied to a battery. The height direction of the battery cell structure is the Z-axis direction.

[0091] The battery core structure includes a shell body 10. The shell body 10 is columnar. In some examples, the shell body 10 is cylindrical.

[0092] See also Figure 2 As shown, the pole core 60 is accommodated inside the shell body 10. Specifically, the shell body 10 is provided with a bottom wall 101 and a side wall 102, the side wall 102 is connected to the bottom wall 101, the bottom wall 101 and the side wall 102 form a cavity, the cavity is cylindrical, and the pole core 60 is accommodated in the cavity.

[0093] See also Figure 3 and Figure 4 As shown, the battery cell structure includes a top cover assembly. The top cover assembly includes a shell cover 20. In some examples, the shell cover 20 is cylindrical.

[0094] The housing cover 20 is connected to the housing body 10. Exemplarily, the housing cover 20 is connected to the housing body 10 by welding, so that the housing cover 20 and the housing body 10 are sealed.

[0095] The shell cover 20 is made of metal. In some examples, the shell cover 20 is a stainless steel cover.

[0096] The thickness of the shell cover 20 is the thickness of the shell cover 20 in the height direction of the battery cell structure. In some examples, the thickness of the shell cover 20 may be 0.1 mm to 0.3 mm, that is, the thickness of the shell cover 20 is greater than or equal to 0.1 mm, and the thickness of the shell cover 20 is less than or equal to 0.3 mm.

[0097] The housing cover 20 is provided with an opening 201 . The opening 201 is circular in shape. The center of the opening 201 is located on the axis of the housing cover 20 .

[0098] The top cover assembly further includes a pole 30. The pole 30 may be cylindrical.

[0099] The pole 30 is located in the opening 201 of the housing cover 20. The pole 30 is arranged on one side of the pole core 60 at the height of the battery cell structure.

[0100] The top cover assembly also includes a connector 40. The connector 40 may be annular. In some examples, the axis of the connector 40 coincides with the axis of the shell cover 20.

[0101] The connector 40 is connected to the shell cover 20. Exemplarily, the connector 40 is welded to the shell cover 20 so that the connector 40 is sealed to the shell cover 20. In the height direction of the battery cell structure, the projection of the weld mark between the connector 40 and the shell cover 20 does not overlap with the projection of the weld mark between the shell cover 20 and the shell body 10. This arrangement can prevent the two weld marks from interfering with each other, and can also prevent the problem of cold welding or leaking welding.

[0102] The material of the connecting member 40 is metal. In some examples, the connecting member 40 can be a nickel sheet or a stainless steel sheet with a nickel-plated surface.

[0103] The thickness of the connector 40 is equal to the thickness of the connector 40 in the height direction of the battery cell structure. In some examples, the thickness of the connector 40 can be 0.01mm to 0.08mm, that is, the thickness of the connector 40 is greater than or equal to 0.01mm, and less than or equal to 0.08mm. When the thickness of the connector 40 is less than 0.01mm, the connector 40 is easily deformed by heat during the welding process, resulting in poor sealing between the connector 40 and the shell cover 20, increasing the risk of leakage. When the thickness of the connector 40 is greater than 0.08mm, the material usage of the connector 40 will increase, resulting in increased production costs. By making the thickness of the connector 40 greater than or equal to 0.01mm and less than or equal to 0.08mm, the connector 40 is not easily deformed by heat during the welding process, reducing the risk of leakage, reducing the material usage of the connector 40, and reducing production costs.

[0104] The top cover assembly further includes a sealing film 50. The sealing film 50 is made of insulating material.

[0105] The inner diameter of the connecting member 40 is smaller than the diameter of the opening 201. In the height direction of the battery cell structure, the projection of the pole 30 partially overlaps with the projection of the connecting member 40.

[0106] The sealing film 50 is bonded between the pole 30 and the connecting member 40. In this way, the sealing film 50 can be sealed between the pole 30 and the connecting member 40, so that the opening 201 of the shell cover 20 can be sealed.

[0107] The sealing film 50 can be bonded between the pole 30 and the connector 40 by heat pressing.

[0108] In some examples, the thickness of the sealant film 50 before hot pressing may be 0.08 mm to 0.2 mm, that is, the thickness of the sealant film 50 before hot pressing is greater than or equal to 0.08 mm and less than or equal to 0.2 mm.

[0109] The sealant film 50 softens during the hot pressing process. Figure 5 As shown, the sealing film 50 will be solidified and formed after hot pressing, and the sealing film 50 can be in a circular ring shape. In some examples, the axis of the sealing film 50 coincides with the axis of the shell cover 20.

[0110] exist Figure 5 In the direction from left to right, the portion between the first dotted line and the second dotted line and the portion between the third dotted line and the fourth dotted line are the bonding portion 502, the portion between the second dotted line and the third dotted line is the overflow portion 503, and the portion on the left side of the first dotted line and the portion on the right side of the fourth dotted line are the overflow portion 501.

[0111] See also Figure 5 As shown, the sealant film 50 includes an overflow portion 501, an adhesive portion 502 and an inner overflow portion 503. In the radial direction of the sealant film 50, the overflow portion 501 is connected to the outer edge of the adhesive portion 502, and the inner overflow portion 503 is connected to the inner edge of the adhesive portion 502. Figure 5 and Figure 6 As shown, in the height direction of the cell structure, the bonding portion 502 is located between the pole 30 and the connector 40. The overflow portion 501 and the overflow portion 503 are the portions of the sealant film 50 that overflow from between the pole 30 and the connector 40 during the hot pressing process.

[0112] The thickness H1 of the overflow portion 501 is the thickness of the overflow portion 501 in the height direction of the battery cell structure. The thickness H3 of the inner overflow portion 503 is the thickness of the inner overflow portion 503 in the height direction of the battery cell structure. The thickness H2 of the adhesive portion 502 is the thickness of the adhesive portion 502 in the height direction of the battery cell structure.

[0113] In some examples, the thickness H1 of the overflow portion 501 and the thickness H3 of the overflow portion 503 are both greater than the thickness H2 of the bonding portion 502. The thickness H2 of the bonding portion 502 is greater than or equal to 1 / 5 of the thickness of the sealing film 50 before hot pressing, and the thickness H2 of the bonding portion 502 is less than or equal to 4 / 5 of the thickness of the sealing film 50 before hot pressing. When the thickness H2 of the bonding portion 502 is less than 1 / 5 of the thickness of the sealing film 50 before hot pressing, the bonding portion 502 is too thin and cannot provide sufficient bonding strength, resulting in easy separation of the pole 30 and the connector 40. When the thickness H2 of the bonding portion 502 is greater than 4 / 5 of the thickness of the sealing film 50 before hot pressing, the bonding portion 502 is too thick and the bonding portion 502 is prone to incomplete curing, resulting in a decrease in the bonding strength of the bonding portion 502. By ensuring that the thickness H2 of the bonding portion 502 is greater than or equal to 1 / 5 of the thickness of the sealing film 50 before hot pressing, and the thickness H2 of the bonding portion 502 is less than or equal to 4 / 5 of the thickness of the sealing film 50 before hot pressing, the bonding portion 502 is completely cured, and the bonding strength of the bonding portion 502 can be improved, making it difficult for the pole 30 and the connector 40 to be separated.

[0114] The positive pole ear 601 of the pole core 60 (see Figure 2 The negative pole ear of the pole core 60 can be electrically connected to the shell body 10 or the shell cover 20.

[0115] In the height direction of the cell structure, the projection of the shell cover 20 does not overlap with the projection of the pole 30. This arrangement, that is, the shell cover and the pole are arranged roughly horizontally, thereby avoiding the excessive thickness of the top cover assembly as a whole caused by the overlapping projections of the shell cover and the pole, so that the thickness of the top cover assembly at the connection part is reduced, that is, the thickness of the top cover assembly at the connection part where the pole 30, the sealing film 50, the shell cover 20 and the connector 40 are connected can be reduced, thereby reducing the height space occupied by the top cover assembly in the battery, which can increase the capacity of the battery and improve the energy density of the battery.

[0116] It should be noted that the thickness of the top cover assembly at the connecting portion of the pole 30, the sealing film 50, the shell cover 20 and the connector 40 may be the thickness H of the connecting portion of the top cover assembly. The thickness H of the connecting portion of the top cover assembly may be equal to the thickness of the connecting portion of the shell cover 20 and the connector 40 in the height direction of the battery cell structure. Alternatively, the thickness H of the connecting portion of the top cover assembly may also be equal to the thickness of the connecting portion of the pole 30, the sealing film 50 and the connector 40.

[0117] In a possible implementation, the thickness H of the connecting portion of the top cover assembly may be 0.2 mm to 0.3 mm, that is, the thickness H of the connecting portion of the top cover assembly is greater than or equal to 0.2 mm and less than or equal to 0.3 mm. The thickness of the shell cover 20 may be 0.15 mm to 0.25 mm, that is, the thickness of the shell cover 20 is greater than or equal to 0.15 mm and less than or equal to 0.25 mm. The thickness of the connector 40 may be 0.035 mm to 0.075 mm, that is, the thickness of the connector 40 is greater than or equal to 0.035 mm and less than or equal to 0.075 mm. The thickness of the bonding portion 502 of the sealing film 50 may be 0.02 mm to 0.06 mm, that is, the thickness of the bonding portion 502 of the sealing film 50 is greater than or equal to 0.02 mm and less than or equal to 0.06 mm. The maximum thickness of the pole 30 may be 0.1 mm to 0.2 mm, that is, the maximum thickness of the pole 30 is greater than or equal to 0.1 mm and less than or equal to 0.2 mm.

[0118] Exemplarily, the thickness H of the connecting portion of the top cover assembly may be 0.2 mm to 0.3 mm, that is, the thickness H of the connecting portion of the top cover assembly is greater than or equal to 0.2 mm and less than or equal to 0.3 mm. The thickness of the shell cover 20 may be 0.15 mm. The thickness of the connector 40 may be 0.05 mm. The thickness of the bonding portion 502 of the sealing film 50 may be 0.05 mm. The maximum thickness of the pole 30 may be 0.1 mm.

[0119] In one possible implementation, see Figure 7 As shown, the pole 30 includes a pole body 31 and a boss 32. In some examples, the pole body 31 and the boss 32 are formed in one piece. The pole body 31 is annular, and the boss 32 is cylindrical.

[0120] exist Figure 7 The portion between the two dotted lines is the boss 32. Figure 7 The remaining portion after removing the boss 32 is the pole body 31 .

[0121] The pole body 31 is connected to the edge of the boss 32. The inner diameter of the pole body 31 is equal to the diameter of the boss 32. The diameter of the boss 32 is smaller than the inner diameter of the connector 40.

[0122] The axis of the pole 30 extends along the height direction of the cell structure. In the axial direction of the pole 30 , one end of the pole body 31 is aligned with one end of the boss 32 .

[0123] The thickness H4 of the pole body 31 is the thickness of the pole body 31 in the height direction of the battery cell structure. The thickness H5 of the boss 32 is the thickness of the boss 32 in the height direction of the battery cell structure. The thickness H4 of the pole body 31 is less than the thickness H5 of the boss 32. It can be understood that the maximum thickness of the pole 30 is equal to the thickness H5 of the boss 32.

[0124] The connection part between the pole 30 and the sealing film 50 is the pole body 31. The pole body 31 is located in the opening 201 of the shell cover 20. The sealing film 50 is bonded between the pole body 31 and the connecting member 40.

[0125] In the height direction of the cell structure, the thickness of the connector 40 is less than the thickness of the shell cover 20, and the thickness of the connector 40 is less than the thickness of the pole body 31. In this way, when the thickness H of the connecting portion of the top cover assembly is equal to the thickness of the connecting portion of the connector 40 and the shell cover 20, the thickness H of the connecting portion of the top cover assembly is less than the thickness of the connecting portion of the top cover assembly in the related art where the pole, the sealing film and the shell cover are connected, thereby reducing the thickness H of the connecting portion of the top cover assembly, thereby reducing the height space occupied by the top cover assembly in the battery, and increasing the capacity of the battery and the energy density of the battery.

[0126] When the thickness H of the connecting part of the top cover assembly is equal to the thickness of the connecting part of the connector 40, the sealing film 50 and the pole body 31, the thickness H of the connecting part of the top cover assembly is smaller than the thickness of the connecting part of the top cover assembly in the related art where the pole, the sealing film and the shell cover are connected, thereby reducing the thickness H of the connecting part of the top cover assembly, thereby reducing the height space occupied by the top cover assembly in the battery, thereby increasing the capacity of the battery and improving the energy density of the battery.

[0127] In a possible implementation, in the height direction of the battery cell structure, the sum of the thickness of the connector 40, the sealing film and the shell cover 20 is less than the thickness of the pole 30. This arrangement can prevent the connector 40 from interfering with the connection between the pole 30 and the positive electrode ear 601. In addition, the battery cell structure can be prevented from being too thick as a whole, which affects the energy density.

[0128] In a possible implementation, there is a gap between the pole body 31 and the shell cover 20 in the radial direction of the pole 30. This arrangement can prevent the pole body 31 from contacting the shell cover 20, thereby preventing the positive and negative pole ears 601 of the pole core 60 from short-circuiting.

[0129] In the radial direction of the pole 30, there is a gap between the connector 40 and the boss 32. In this way, a glue storage tank can be formed between the connector 40 and the boss 32, and the glue storage tank can store the glue overflowing from the sealing glue film 50 during the hot pressing process to prevent the overflowed glue from affecting the flatness of the battery structure.

[0130] In one possible implementation, see Figure 7 As shown, in the axial direction of the pole 30 , the boss 32 includes a first end 321 and a second end 322 . The first end 321 is flush with the pole body 31 .

[0131] See also Figure 6 and Figure 7 As shown, the second end 322 of the boss 32 can face the cavity of the housing body 10. The outer diameter of the housing cover 20 is greater than the inner diameter of the cavity. In this way, the housing cover 20 can be connected to the top of the housing body 10.

[0132] See also Figure 7 As shown, the boss 32 is provided with a liquid injection hole 323, and the liquid injection hole 323 penetrates the boss 32. The electrolyte can be injected into the cavity of the shell body 10 through the liquid injection hole 323.

[0133] The injection hole 323 may be cylindrical in shape. The axis of the injection hole 323 extends along the axial direction of the pole 30. In some examples, the axis of the injection hole 323, the axis of the pole body 31 and the axis of the boss 32 coincide with each other, that is, the axis of the injection hole 323 and the axis of the pole 30 coincide with each other.

[0134] The battery cell structure includes a sealing cover 70 (see Figure 1 and Figure 2 The sealing cover 70 is made of metal.

[0135] The sealing cover 70 is connected to the boss 32. In some examples, the sealing cover 70 is connected to the boss 32 by laser welding.

[0136] The sealing cover 70 blocks the liquid injection hole 323 to prevent the electrolyte in the housing body 10 from leaking out of the liquid injection hole 323 .

[0137] The diameter of the injection hole 323 can be 0.6mm to 2mm, that is, the diameter of the injection hole 323 is greater than or equal to 0.6mm and less than or equal to 2mm. When the diameter of the injection hole 323 is less than 0.6mm, the flow rate of the injection will be slow and the injection efficiency will be low. When the diameter of the injection hole 323 is greater than 2mm, the sealing difficulty of the injection hole 323 will increase. By making the diameter of the injection hole 323 greater than or equal to 0.6mm and less than or equal to 2mm, the flow rate of the injection can be accelerated, the injection efficiency can be improved, and the sealing difficulty of the injection hole 323 can be reduced.

[0138] In some examples, the sealing cover 70 may be a sealing sheet. The thickness of the sealing sheet is the thickness of the sealing sheet in the height direction of the battery cell structure.

[0139] The thickness of the sealing piece can be 0.05mm to 0.15mm, that is, the thickness of the sealing piece is greater than or equal to 0.05mm, and less than or equal to 0.15mm. When the thickness of the sealing piece is less than 0.05mm, the sealing piece is easily deformed by heat during the welding process, resulting in poor sealing of the sealing piece to the injection hole, increasing the risk of leakage. When the thickness of the sealing piece is greater than 0.15mm, the material consumption of the sealing piece will increase, resulting in increased production costs. By making the thickness of the sealing piece greater than or equal to 0.05mm, and less than or equal to 0.15mm, the sealing piece is not easily deformed by heat during the welding process, reducing the risk of leakage, reducing the material consumption of the sealing piece, and reducing production costs.

[0140] In a possible embodiment, the connecting member 40 is located on the side of the shell cover 20 facing the pole core 60 (see Figure 2 shown).

[0141] The positive pole ear 601 of the pole core 60 is welded to the boss 32 of the pole column 30. Specifically, the positive pole ear 601 of the pole core 60 is welded to the second end 322 of the boss 32.

[0142] A first insulating member 91 is provided between the positive electrode ear 601 and the connecting member 40 (see Figure 2 Such arrangement can prevent the positive electrode ear 601 from contacting with the connecting member 40, thereby preventing the positive electrode ear 601 and the negative electrode ear of the pole core 60 from short-circuiting.

[0143] The first insulating member 91 is made of insulating material. In some examples, the first insulating member 91 may be a polyimide tape or a polyethylene terephthalate (PET) tape.

[0144] In a possible implementation, in the height direction of the battery cell structure, the top surface of the connector 40 is located on the side of the bottom surface of the pole 30 away from the pole core 60. This arrangement can prevent the connector 40 from interfering with the welding of the pole 30 and the positive tab 601.

[0145] In the height direction of the battery core structure, the surface of the connecting member 40 facing away from the pole core 60 is the top surface of the connecting member 40 .

[0146] In the height direction of the battery cell structure, the side of the pole 30 facing the pole core 60 is the bottom surface of the pole 30 .

[0147] Exemplarily, the top surface of the connecting member 40 is located on the side of the bottom surface of the boss 32 of the pole 30 facing away from the pole core 60 .

[0148] In a possible embodiment, the battery cell structure further includes a positive electrode connecting sheet 80 (see Figure 1 shown).

[0149] The positive electrode connecting piece 80 is welded to the pole 30 . In some examples, the positive electrode connecting piece 80 is welded to the first end 321 of the boss 32 of the pole 30 .

[0150] In some examples, the diameter of the boss 32 can be 1 mm to 5 mm, that is, the diameter of the boss 32 is greater than or equal to 1 mm and less than or equal to 5 mm. When the diameter of the boss 32 is less than 1 mm, the welding area of ​​the boss 32 between the positive electrode connecting piece 80 and the pole 30 will be small, and the connection stability between the positive electrode connecting piece 80 and the pole 30 will be poor. When the diameter of the boss 32 is greater than 5 mm, the material usage of the pole 30 will increase, resulting in increased production costs. By making the diameter of the boss 32 greater than or equal to 1 mm and less than or equal to 5 mm, the welding area of ​​the boss 32 between the positive electrode connecting piece 80 and the pole 30 can be increased, the connection stability between the positive electrode connecting piece 80 and the pole 30 can be improved, and the material usage of the pole 30 can be reduced, thereby reducing production costs.

[0151] In the height direction of the battery cell structure, the thickness of the boss 32 can be 0.1mm to 0.5mm, that is, the thickness of the boss 32 is greater than or equal to 0.1mm, and less than or equal to 0.5mm. When the thickness of the boss 32 is less than 0.1mm, the boss 32 is easily welded through during the welding process. When the thickness of the boss 32 is greater than 0.5mm, the material usage of the pole 30 will increase, resulting in increased production costs. By making the thickness of the boss 32 greater than or equal to 0.1mm, and less than or equal to 0.5mm, the boss 32 is not easily welded through during the welding process, the material usage of the pole 30 is reduced, and the production cost is reduced.

[0152] The end of the positive electrode connecting piece 80 that does not contact the pole 30 is a positive electrode pin 801 (see Figure 1 , Figure 6 and Figure 8 shown).

[0153] See also Figure 8 As shown, in the radial direction of the pole 30, the positive pin 801 of the positive connecting piece 80 is located on one side of the side wall 102 of the shell body 10. In this way, in the radial direction of the pole 30, the battery can supply power to the outside from one side of the side wall 102 of the shell body 10.

[0154] In the height direction of the battery cell structure, the projection of the welding area of ​​the positive electrode connecting sheet 80 does not overlap with the projection of the sealing sheet, and the projection of the welding area of ​​the positive electrode connecting sheet 80 does not overlap with the projection of the sealing film 50. In this way, in the height direction of the battery cell structure, it is possible to avoid the welding area of ​​the positive electrode connecting sheet 80 being located in the area corresponding to the sealing sheet and the injection hole 323, resulting in the sealing sheet being welded through. It is also possible that the sealing film 50 is not easily melted during the welding process of the positive electrode connecting sheet 80.

[0155] It should be noted that the welding area between the positive electrode connecting sheet 80 and the electrode post 30 is the welding area of ​​the positive electrode connecting sheet 80 .

[0156] In a possible implementation, the battery cell structure further includes a negative electrode connecting sheet 90 (see Figure 1 and Figure 6 shown).

[0157] The negative electrode connecting piece 90 is welded to the bottom wall 101 of the shell body 10. The end of the negative electrode connecting piece 90 that is not in contact with the shell body 10 is the negative electrode pin 901. Exemplarily, the thickness of the shell body 10 is greater than or equal to 1.5 mm, that is, the thickness of the side wall 102 and the bottom wall 101 of the shell body 10 are both greater than or equal to 1.5 mm.

[0158] In some examples, in the radial direction of the pole 30 , the positive electrode pin 801 of the positive electrode connecting piece 80 and the negative electrode pin 901 of the negative electrode connecting piece 90 are located on one side of the side wall 102 of the housing body 10 .

[0159] Embodiment 2

[0160] See also Fig. 9 As shown, the cell structure in the second embodiment is different from the cell structure in the first embodiment in that the first end 321 of the boss 32 faces the cavity, and the outer diameter of the shell cover 20 is less than or equal to the inner diameter of the cavity. In this way, the shell cover 20 can be connected to the inner wall of the cavity of the shell body 10.

[0161] The connecting member 40 is located on the side of the housing cover 20 away from the pole core 60. The battery core structure is not provided with the first insulating member 91.

[0162] The positive pole ear 601 of the pole core 60 is welded to the pole column 30. The positive pole ear 601 and the boss 32 are arranged opposite to each other.

[0163] In the height direction of the battery cell structure, the projection of the connector 40 covers the side wall 102 of the housing body 10 .

[0164] The rest of the structure of the battery cell in the second embodiment is the same as that of the battery cell in the first embodiment.

[0165] Embodiment 3

[0166] See also Figures 10 to 12 As shown, the cell structure in the third embodiment differs from the cell structure in the second embodiment in that the sealing cover 70 includes a sealing sheet 71 and a limiting platform 72, the limiting platform 72 is arranged on the sealing sheet 71, the limiting platform 72 faces the cavity of the shell body 10, and the limiting platform 72 is inserted into the injection hole 323. In this way, the position of the sealing cover 70 on the pole 30 can be limited, so that when the sealing cover 70 is welded to the pole 30, it is convenient to position the sealing cover 70.

[0167] The positive electrode connecting piece 80 is welded to the sealing piece 71. Specifically, in the height direction of the battery cell structure, the area where the sealing piece 71 overlaps with the limiting platform 72 is the first area of ​​the sealing piece 71. It can be understood that in the height direction of the battery cell structure, the projection of the first area of ​​the sealing piece 71 coincides with the projection of the limiting platform 72. The positive electrode connecting piece 80 is welded to the first area of ​​the sealing piece 71. In this way, when the positive electrode connecting piece 80 and the sealing cover 70 are welded, the positive electrode connecting piece 80 is welded to the area where the sealing piece 71 overlaps with the limiting platform 72, so that the sealing cover 70 is not easy to be welded through.

[0168] The thickness of the shell body 10 is less than 1.5 mm, that is, the thickness of the bottom wall 101 and the side wall 102 of the shell body 10 are both less than 1.5 mm. In some examples, the bottom wall 101 of the shell body 10 is welded to the negative electrode connecting piece 90, and the thickness of the welding area of ​​the negative electrode connecting piece 90 is less than the thickness of other areas of the negative electrode connecting piece 90. In this way, during the welding process of the bottom wall 101 of the shell body 10 and the negative electrode connecting piece 90, by reducing the thickness of the welding area of ​​the negative electrode connecting piece 90, the bottom wall 101 of the shell body 10 can be made difficult to be welded through.

[0169] It should be noted that the welding area between the negative electrode connecting sheet 90 and the bottom wall 101 of the shell body 10 is the welding area of ​​the negative electrode connecting sheet 90. The other area of ​​the negative electrode connecting sheet 90 is the area remaining after the welding area of ​​the negative electrode connecting sheet 90 is removed.

[0170] The rest of the structure of the battery cell in the third embodiment is the same as that of the battery cell in the second embodiment.

[0171] Embodiment 4

[0172] See also Fig.13 and Fig.14 As shown, the cell structure in the fourth embodiment differs from the cell structure in the second embodiment in that, in the height direction of the cell structure, the positive pin 801 of the positive connecting piece 80 and the negative pin 901 of the negative connecting piece 90 are located on the side of the pole away from the shell body 10.

[0173] The negative electrode connecting piece 90 may be welded to the connecting member 40. In other embodiments, the negative electrode connecting piece 90 may also be welded to the shell cover 20.

[0174] In the height direction of the battery cell structure, the projection of the welding area of ​​the negative electrode connecting sheet 90 does not overlap with the projection of the sealing film. In this way, during the welding process of the negative electrode connecting sheet 90, the sealing film 50 is not easy to melt.

[0175] A second insulating member 92 is provided between the positive electrode connecting piece 80 and the connecting member 40. This arrangement can prevent the positive electrode connecting piece 80 from contacting the connecting member 40, thereby preventing the positive electrode ear 601 and the negative electrode ear of the pole core 60 from short-circuiting.

[0176] The second insulating member 92 is made of insulating material. In some examples, the second insulating member 92 can be a polyimide tape or a polyethylene terephthalate (PET) tape.

[0177] The rest of the structure of the battery cell in the fourth embodiment is the same as that of the battery cell in the second embodiment.

[0178] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell structure, characterized in that: include: A housing body (10); A top cover assembly, the top cover assembly comprising a shell cover (20), a pole (30), a sealing film (50) and a connecting piece (40); The shell cover (20) is connected to the shell body (10), the shell cover (20) is provided with an opening (201), the connecting piece (40) is connected to the shell cover (20), the pole (30) is located in the opening (201) of the shell cover (20), and the sealing film (50) is bonded between the pole (30) and the connecting piece (40); In the height direction of the battery core structure, the projection of the shell cover (20) does not overlap with the projection of the pole (30).

2. The battery cell structure according to claim 1, characterized in that: The pole (30) comprises a pole body (31) and a boss (32), the pole body (31) being connected to the edge of the boss (32), the pole body (31) being located in the opening (201) of the shell cover (20), and the sealing film (50) being bonded between the pole body (31) and the connecting piece (40).

3. The battery cell structure according to claim 2, characterized in that: In the height direction of the battery core structure, the thickness of the connecting member (40) is less than the thickness of the shell cover (20); and / or, In the height direction of the battery core structure, the thickness of the pole body (31) is less than the thickness of the boss (32); and / or, In the height direction of the battery core structure, the thickness of the connecting member (40) is smaller than the thickness of the pole body (31).

4. The battery cell structure according to claim 2, characterized in that: In the height direction of the battery core structure, the sum of the thickness of the connecting member (40), the thickness of the sealing film (50) and the shell cover (20) is less than the thickness of the pole (30).

5. The battery cell structure according to claim 2, characterized in that: It also includes a pole core (60), which is arranged inside the shell body (10), and the connecting member (40) is located on the side of the shell cover (20) facing the pole core (60), the positive pole ear (601) of the pole core (60) is welded to the boss (32) of the pole column (30), and a first insulating member (91) is arranged between the positive pole ear (601) and the connecting member (40).

6. The battery cell structure according to claim 5, characterized in that: In the height direction of the battery core structure, the top surface of the connecting member (40) is located on the side of the bottom surface of the pole (30) facing away from the pole core (60).

7. The battery cell structure according to claim 2, characterized in that: It also includes a pole core (60), which is arranged inside the shell body (10), and the connecting piece (40) is located on the side of the shell cover (20) away from the pole core (60), the positive pole ear (601) of the pole core (60) is welded to the pole column (30), and the positive pole ear (601) and the boss (32) are arranged opposite to each other.

8. The battery cell structure according to claim 7, characterized in that: In the radial direction of the pole (30), there is a gap between the connecting piece (40) and the boss (32).

9. The battery cell structure according to claim 7, characterized in that: In the height direction of the battery core structure, the projection of the connecting member (40) covers the side wall of the housing body (10).

10. The battery core structure according to claim 2, characterized in that: In the axial direction of the pole (30), the boss (32) comprises a first end (321) and a second end (322), and the first end (321) is flush with the pole body (31); The shell body (10) is provided with a bottom wall (101) and a side wall (102); the side wall (102) is connected to the bottom wall (101); the bottom wall (101) and the side wall (102) form a cavity.

11. The battery core structure according to claim 10, characterized in that: The first end (321) of the boss (32) faces the cavity, and the outer diameter of the shell cover (20) is less than or equal to the inner diameter of the cavity; or, The second end (322) of the boss (32) faces the cavity, and the outer diameter of the shell cover (20) is greater than the inner diameter of the cavity.

12. The battery core structure according to claim 2, characterized in that: The diameter of the boss (32) is 1 mm to 5 mm; and / or, In the height direction of the battery core structure, the thickness of the boss (32) is 0.1 mm to 0.5 mm; and / or, The shell cover (20) has a thickness of 0.1 mm to 0.3 mm, and the shell cover (20) is a stainless steel cover; and / or, The thickness of the connecting piece (40) is 0.01 mm to 0.08 mm, and the connecting piece (40) is a nickel sheet or a stainless steel sheet with a nickel plating surface; and / or, The thickness of the connecting portion of the top cover assembly is 0.2 mm to 0.3 mm; and / or, The thickness of the adhesive portion (502) of the sealing film (50) is 0.02 mm to 0.06 mm; and / or, The maximum thickness of the pole (30) is 0.1 mm to 0.2 mm.

13. The battery core structure according to any one of claims 1 to 12, characterized in that: In the height direction of the battery core structure, the projection of the weld mark between the connecting piece (40) and the shell cover (20) does not overlap with the projection of the weld mark between the shell cover (20) and the shell body (10).

14. The battery core structure according to any one of claims 1 to 12, characterized in that: The sealing film (50) comprises an overflow portion (501), an adhesive portion (502) and an inner overflow portion (503); in the radial direction of the sealing film (50), the overflow portion (501) is connected to the outer edge of the adhesive portion (502), and the inner overflow portion (503) is connected to the inner edge of the adhesive portion (502); and / or, The thickness of the overflow portion (501) and the thickness of the overflow portion (503) are both greater than the thickness of the bonding portion (502).

15. The battery core structure according to any one of claims 2 to 12, characterized in that: It also includes a sealing cover (70), the boss (32) is provided with a liquid injection hole (323), the liquid injection hole (323) passes through the boss (32), the sealing cover (70) is connected to the boss (32), and the sealing cover (70) blocks the liquid injection hole (323); and / or, The axis of the injection hole (323) coincides with the axis of the pole (30); and / or, The diameter of the injection hole (323) is 0.6 mm to 2 mm.

16. The battery core structure according to claim 15, characterized in that: Also includes a positive electrode connecting sheet (80); In the height direction of the battery cell structure, the positive electrode pin (801) of the positive electrode connecting sheet (80) is located on the side of the pole (30) facing away from the shell body (10); or, in the radial direction of the pole (30), the positive electrode pin (801) of the positive electrode connecting sheet (80) is located on the side of the side wall (102) of the shell body (10).

17. The battery core structure according to claim 16, characterized in that: The positive electrode connecting sheet (80) is welded to the pole (30), and in the height direction of the battery core structure, the projection of the welding area of ​​the positive electrode connecting sheet (80) does not overlap with the projection of the sealing sheet (71); and / or, The projection of the welding area of ​​the positive electrode connecting sheet (80) does not overlap with the projection of the sealing film (50).

18. The battery core structure according to claim 16, characterized in that: The sealing cover (70) comprises a sealing sheet (71) and a limiting platform (72), wherein the limiting platform (72) is arranged on the sealing sheet (71), the limiting platform (72) faces the cavity of the shell body (10), and the limiting platform (72) is inserted into the liquid injection hole (323); The positive electrode connecting sheet (80) is welded to the sealing sheet (71).

19. The battery core structure according to claim 16, characterized in that: It also includes a negative electrode connecting piece (90), the negative electrode connecting piece (90) is welded to the shell cover (20) or the connecting piece (40), the negative electrode pin (901) of the negative electrode connecting piece (90) is located on the side of the pole (30) away from the shell body (10), and a second insulating piece (92) is provided between the positive electrode connecting piece (80) and the connecting piece (40).

20. The battery core structure according to claim 19, characterized in that: The projection of the welding area of ​​the negative electrode connecting sheet (90) does not overlap with the projection of the sealing adhesive film (50).

21. The battery core structure according to claim 16, characterized in that: It also includes a negative electrode connecting sheet (90), wherein the negative electrode connecting sheet (90) is welded to the bottom wall (101) of the shell body (10).

22. The battery core structure according to claim 21, characterized in that: The thickness of the welding region of the negative electrode connecting sheet (90) is smaller than the thickness of other regions of the negative electrode connecting sheet (90).

23. A battery, characterized in that: Comprising a battery core structure as described in any one of claims 1 to 22.

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