CN214203912U

CN214203912U - Battery with a battery cell

Info

Publication number: CN214203912U
Application number: CN202120455729.3U
Authority: CN
Inventors: 卫志达; 彭宁; 谢斌
Original assignee: Zhuhai Cosmx Battery Co Ltd
Current assignee: Zhuhai Cosmx Battery Co Ltd
Priority date: 2021-03-02
Filing date: 2021-03-02
Publication date: 2021-09-14
Anticipated expiration: 2031-03-02
Also published as: WO2022184081A1

Abstract

The utility model provides a battery. The battery of the utility model comprises a battery cell component and a shell component, wherein the shell component comprises a shell and a top cover, the shell and the top cover are enclosed into a holding cavity, and the holding cavity is used for holding the battery cell component; the shell comprises a bottom wall and an annular side wall which are connected with each other, and the bottom wall and the top cover are respectively positioned at two ends of the annular side wall; the bottom wall is provided with a liquid injection hole, and a sealing cover for sealing the liquid injection hole is welded at the liquid injection hole. Thereby the setting effect of notes liquid hole and closing cap has been improved, the yields that is favorable to promoting the battery.

Description

Battery with a battery cell

Technical Field

The utility model relates to a battery technology field especially relates to a battery.

Background

Batteries are classified into two types, chemical batteries and physical batteries, wherein the chemical batteries are most commonly used and mainly comprise an anode, a cathode and an electrolyte thereof.

A conventional battery, such as a button battery, mainly includes a casing and a battery cell enclosed in the casing, the casing usually includes a casing and a top cover insulated from each other, the top cover is usually connected to a first tab of the battery cell, and the casing is usually connected to a second tab of the battery cell. In order to conveniently inject a sufficient amount of electrolyte into the casing, a liquid injection hole is usually formed in the top cover, and after the electrolyte is injected, the liquid injection hole is sealed by welding with a sealing cover.

However, the effect of providing the liquid injection hole in the top cover and welding the sealing cover is not good, which may reduce the yield of the button cell.

SUMMERY OF THE UTILITY MODEL

The utility model provides a battery, this battery have improved the setting effect of notes liquid hole and closing cap, are favorable to promoting button cell's yields.

The utility model provides a battery, which comprises a battery component and a shell component, wherein the shell component comprises a shell and a top cover, the shell and the top cover enclose into a holding cavity, and the holding cavity is used for holding the battery component; the shell comprises a bottom wall and an annular side wall which are connected with each other, and the bottom wall and the top cover are respectively positioned at two ends of the annular side wall; be provided with on the diapire and annotate the liquid hole, it has the welding to annotate the welding of liquid hole department seal closure in annotating the liquid hole.

The utility model discloses a battery includes shell subassembly and shell subassembly, and the shell subassembly includes casing and top cap, and casing and top cap enclose synthetic holding chamber, and the holding chamber is used for holding shell subassembly, and the shell subassembly can be through the outside electric energy of exporting of shell subassembly, perhaps, the electric energy that the shell subassembly can receive external input through the shell subassembly. The casing includes interconnect's diapire and annular lateral wall, and diapire and top cap are located the both ends of annular lateral wall respectively.

The bottom wall is provided with a liquid injection hole, and the sealing cover for sealing the liquid injection hole is welded at the liquid injection hole. On the one hand, because the diapire of casing is compared in that top cap associative structure is less, overall structure is simpler and the space is bigger to not only be convenient for annotate the setting in liquid hole, the welding of the follow-up closing cap of being convenient for moreover is favorable to promoting the welding effect of closing cap, and then is favorable to promoting the yields of battery, reduces the degree of difficulty of the manufacturing process of battery. On the other hand, because the second sheetmetal is the aluminum alloy piece usually, the welding performance of aluminum alloy is relatively poor, and the casing is steel casing usually, and the welding performance of steel is relatively good, consequently, will annotate the liquid hole and set up the effect that is favorable to improving the sealed cap welded seal and annotates the liquid hole on the diapire of casing to be favorable to reducing the weeping probability of battery, and then be favorable to promoting the yields of battery.

In the battery as described above, optionally, the top cover includes a first metal sheet having a through hole, an insulating seal member, and a second metal sheet, the first metal sheet being connected to one end of the annular side wall, the second metal sheet being connected to the first metal sheet through the insulating seal member and covering the through hole; the electric core assembly is provided with a first tab and a second tab, the electric properties of the first tab and the second tab are opposite, the first tab is connected with the second metal sheet, and the second tab is connected with the shell or the first metal sheet;

in the battery as described above, optionally, the outer surface of the bottom wall is provided with a receiving groove, the liquid injection hole is disposed at the bottom of the receiving groove, and the diameter of the liquid injection hole is smaller than that of the receiving groove; the sealing cover is located in the containing groove, and the diameter of the sealing cover is smaller than that of the containing groove and larger than that of the liquid injection hole.

In the battery as described above, optionally, a difference between the diameter of the accommodating groove and the diameter of the liquid injection hole is greater than or equal to 0.05 mm.

In the battery as described above, optionally, a difference between the diameter of the receiving groove and the diameter of the sealing cap ranges from 0.01mm to 2.5 mm.

Optionally, the depth of the accommodating groove ranges from 0.01mm to 0.15 mm.

In the battery as described above, optionally, the battery core assembly is a winding battery core, the middle of the winding battery core is provided with a shaft hole, and the liquid injection hole and a projection of the shaft hole on the bottom wall at least partially overlap.

In the battery as described above, optionally, the edge of the sealing cover is welded to the inner wall of the accommodating groove to form a first welding seam.

In the battery as described above, optionally, a gap is formed between the edge of the sealing cover and the inner wall of the receiving groove, and the first welding seam fills at least a part of the gap.

In the battery as described above, optionally, the surface of the first weld is formed with a molten pool depression, and the depth of the molten pool depression ranges from 0.005mm to 0.05 mm.

In the battery as described above, optionally, the thickness of the sealing cover is less than or equal to the depth of the receiving groove.

In the battery as described above, optionally, the central region of the sealing cover protrudes in a direction away from the pour hole; the height range of the outer surface of the sealing cover protruding out of the outer surface of the bottom wall is 0.02mm-2 mm; and/or the height range of the inner surface of the sealing cover protruding out of the bottom of the containing groove is 0.01mm-0.05 mm.

In the battery, optionally, one end of the hole wall of the liquid injection hole, which is close to the electric core assembly, is set to be an arc angle; and/or one end of the hole wall of the liquid injection hole, which is far away from the electric core assembly, is set to be an arc angle.

In the battery as described above, optionally, the case is a steel case, and the second metal sheet is an aluminum alloy sheet.

In the battery as described above, optionally, the top end of the inner wall of the annular side wall is provided with an annular step groove, and the outer diameter of the annular step groove is smaller than the outer diameter of the annular side wall; the peripheral edge of the first metal sheet is located in the annular step groove, and the peripheral edge of the first metal sheet is connected with the inner wall of the annular step groove in a welding mode to form a second welding line.

In the battery as described above, optionally, the annular side wall is disposed coaxially with the annular step groove, and a difference between an outer diameter of the annular side wall and an outer diameter of the annular step groove ranges from 0.1mm to 0.18 mm.

In the battery as described above, optionally, the outer peripheral edge of the insulating seal member is formed with a first insulating projection that shields the outer peripheral edge of the second metal sheet.

In the battery as described above, optionally, the inner peripheral edge of the insulating seal member is formed with a second insulating protrusion that shields the inner edge of the first metal sheet.

In the battery as described above, optionally, the outer surface or the inner surface of the second metal sheet is provided with a first annular groove, and the thickness of the groove bottom of the first annular groove is smaller than that of the first metal sheet.

In the battery as described above, optionally, the outer surface or the inner surface of the bottom wall is provided with a second annular groove, and the thickness of the groove bottom of the second annular groove is smaller than that of the bottom wall.

In the battery according to the above, optionally, the first annular groove includes a first outer ring groove and a first inner ring groove, the first inner ring groove is disposed at the bottom of the first outer ring groove, and the width of the notch of the first inner ring groove is smaller than the width of the notch of the first outer ring groove.

In the battery as described above, optionally, the second annular groove includes a second outer ring groove and a second inner ring groove, the second inner ring groove is disposed at a groove bottom of the second outer ring groove, and a notch width of the second inner ring groove is smaller than a notch width of the second outer ring groove.

In the battery as described above, optionally, the minimum thickness of the groove bottom of the first annular groove is in a range of 0.02mm to 0.1 mm.

In the battery as described above, optionally, the first annular groove is disposed coaxially with the case.

In the battery as described above, optionally, the second annular groove is coaxially disposed with the housing.

In the battery as described above, optionally, the second tab is welded to the bottom wall and forms at least one weld mark; one side, facing the electric core component, of each second electrode lug is provided with second electrode lug protective glue, and the second electrode lug protective glue covers the welding seal; and the area of the outer surface of the bottom wall corresponding to the welding mark is free of welding mark.

The battery, optional, the terminal surface of electricity core subassembly with be provided with first insulation glue layer between the diapire, part first insulation glue layer is located second utmost point ear protection glue with between the first terminal surface of electricity core subassembly, and part first insulation glue layer covers what second utmost point ear protection was glued corresponds to weld the position of seal.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a first cross-sectional view of a battery according to an embodiment of the present invention;

fig. 2 is a second cross-sectional view of a battery according to an embodiment of the present invention;

fig. 3 is a third cross-sectional view of a battery according to an embodiment of the present invention;

fig. 4 is a first detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention;

fig. 5 is a second detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention;

fig. 6 is a third detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention;

fig. 7 is a fourth detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention;

fig. 8 is a fifth detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention;

FIG. 9 is an enlarged schematic view at A in FIG. 2;

FIG. 10 is an enlarged view of the first view at B in FIG. 2;

FIG. 11 is an enlarged view of the second embodiment shown at B in FIG. 2;

fig. 12 is a schematic structural diagram of a battery according to an embodiment of the present invention;

fig. 13 is a top view of a battery according to an embodiment of the present invention;

fig. 14 is a bottom view of a battery according to an embodiment of the present invention.

Description of reference numerals:

10-a housing; 11-an annular side wall; 111-annular step groove; 112-a second weld; 12-a bottom wall; 121-liquid injection hole; 122-a receiving groove; 123-a first weld; 1231-bath dip; 124-arc angle; 13-a first metal sheet; 14-sealing cover; 20-a second metal sheet; 21-a first annular groove; 211 — a first outer ring groove; 212-first inner ring groove; 30-an insulating seal; 31 — a first insulating bump; 32-a second insulating bump; 40-electric core assembly; 41-a second tab; 411-second ear protection glue; 412-welding and printing; 42-a first tab; 421-first tab protection glue; 43-first layer of insulating glue; 44-second layer of insulating glue.

Detailed Description

With the development of science and technology, electronic products are more and more in the aspect of people's life, and the normal use of electronic products can not leave the battery. Among them, button cells have been widely used in various electronic products due to their small size, for example: computer motherboard, electronic watch, electronic dictionary, electronic scale, remote controller, electric toy, cardiac pacemaker, electronic hearing aid, counter, camera, etc.

In the related art, a button cell comprises a shell and a top cover, wherein the shell is connected with a negative electrode tab of a battery cell, the top cover is connected with a positive electrode tab of the battery cell, the shell is usually a steel shell, the top cover is usually an aluminum alloy top cover, a liquid injection hole is formed in the top cover, and the aluminum alloy top cover has poor welding performance, so that the sealing cover and the aluminum alloy top cover are poor in welding effect, liquid leakage of the button cell is easily caused, and the yield of the button cell is reduced; moreover, the structure of the top cover is usually complex and the space is small, so that the liquid injection hole and the sealing cover are inconvenient to arrange, and the processing difficulty of the button cell is improved.

In order to solve the technical problem, the utility model provides a battery, this battery is through being provided with on the diapire of shell and annotate the liquid hole to annotate the seal closure in liquid hole welded seal. On the one hand, because the diapire of casing is compared in that top cap associative structure is less, overall structure is simpler and the space is bigger to not only be convenient for annotate the setting in liquid hole, the welding of the follow-up closing cap of being convenient for moreover is favorable to promoting the welding effect of closing cap, and then is favorable to promoting the yields of battery, reduces the degree of difficulty of the manufacturing process of battery. On the other hand, because the second sheetmetal is the aluminum alloy piece usually, the welding performance of aluminum alloy is relatively poor, and the casing is steel casing usually, and the welding performance of steel is relatively good, consequently, will annotate the liquid hole and set up the effect that is favorable to improving the sealed cap welded seal and annotates the liquid hole on the diapire of casing to be favorable to reducing the weeping probability of battery, and then be favorable to promoting the yields of battery.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Fig. 1 is a first cross-sectional view of a battery according to an embodiment of the present invention; fig. 2 is a second cross-sectional view of a battery according to an embodiment of the present invention; fig. 3 is a third cross-sectional view of a battery according to an embodiment of the present invention; fig. 4 is a first detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention; fig. 5 is a second detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention; fig. 6 is a third detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention; fig. 7 is a fourth detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention; fig. 8 is a fifth detailed schematic view of the liquid injection hole covered by the sealing cover according to an embodiment of the present invention; FIG. 9 is an enlarged schematic view at A in FIG. 2; FIG. 10 is an enlarged view of the first view at B in FIG. 2; FIG. 11 is an enlarged view of the second embodiment shown at B in FIG. 2; fig. 12 is a schematic structural diagram of a battery according to an embodiment of the present invention; fig. 13 is a top view of a battery according to an embodiment of the present invention; fig. 14 is a bottom view of a battery according to an embodiment of the present invention.

Referring to fig. 1 and 14, the present embodiment provides a battery including a battery assembly 40 and a housing assembly including a case 10 and a top cover enclosing the case 10 and the top cover into a receiving cavity for receiving the battery assembly 40.

The housing 10 includes a bottom wall 12 and an annular side wall 11 connected to each other, and the bottom wall 12 and the top cover are respectively located at both ends of the annular side wall 11. Illustratively, the bottom wall 12 and the annular side wall 11 are generally one piece, with the bottom wall 12 being located at the bottom end of the annular side wall 11 and the top cover being located at the top end of the annular side wall 11. The housing 10 may be a steel housing.

Optionally, the top cover comprises a first metal sheet 13 having a through hole, an insulating sealing member 30, and a second metal sheet 20, the first metal sheet 13 is connected to one end of the annular sidewall 11, the second metal sheet 20 is connected to the first metal sheet 13 through the insulating sealing member 30, and the through hole is covered. The insulating seal member insulates between the second metal sheet 20 and the first metal sheet 13 on the one hand, and secures sealability between the second metal sheet 20 and the first metal sheet 13 on the other hand. The second metal sheet 20 may be an aluminum alloy sheet.

The core assembly 40 has a first tab 42 and a second tab 41, the first tab 42 and the second tab 41 have opposite electrical properties, the first tab 42 can be connected with the second metal sheet 20, and the first tab 42 is exemplarily connected with the second metal sheet 20 by welding; the second tab 41 may be connected to the case 10 or the first metal sheet 13, and the second tab 41 is connected to the case 10 or the first metal sheet 13 by welding. So that the electric energy generated on the electric core assembly 40 is transmitted outwards through the shell assembly to provide electric energy for the external electric equipment; alternatively, when the battery is a rechargeable battery and the external charging device is used for charging, the electric energy provided by the charging device to the battery can be transmitted to the battery core assembly 40 through the housing assembly.

The bottom wall 12 is provided with a liquid injection hole 121 so as to inject a sufficient amount of electrolyte into the battery through the liquid injection hole 121 during the manufacturing process of the battery, and the sufficient amount of electrolyte is favorable for ensuring the cycle performance of the battery. After the liquid injection is completed, the sealing cap 14 for sealing the liquid injection hole 121 is welded to the liquid injection hole 121, and the sealing cap 14 can prevent the electrolyte from leaking from the liquid injection hole 121.

For example, the core assembly 40 may be a winding type cell, specifically, the winding type cell includes a positive plate, a negative plate, and a diaphragm separating the positive plate and the negative plate; the positive pole piece is provided with a positive pole lug, the positive pole lug can be arranged on the positive pole piece in a welding mode, the negative pole piece is provided with a negative pole lug, and the negative pole lug can be arranged on the negative pole piece in a welding mode; and in the winding process, the positive plate, the negative plate and the diaphragm are wound layer by layer in the same direction from the winding head end to finally form the winding type battery cell. In this embodiment, the first tab may be a positive tab and the second tab is a negative tab, or the first tab may be a negative tab and the second tab is a positive tab. Of course, the core assembly may also be a laminated core or other types of core as long as the requirements of the present embodiment can be met.

In a specific implementation, the first tab 42 may be a positive tab, the second tab 41 may be a negative tab, the core assembly 40 is accommodated in an accommodating cavity surrounded by the casing 10 and the top cover, the first tab 42 is electrically connected to the second metal sheet 20 to enable the second metal sheet 20 to form a positive electrode of the button cell, and the second tab 41 is electrically connected to the casing 10 to enable the casing 10 to form a negative electrode of the button cell. When the button cell is applied to an electronic product, the second metal sheet 20 is connected and conducted with the positive electrode of the electronic product, and the shell 10 is connected and conducted with the negative electrode of the electronic product, so as to supply power to the electronic product.

The battery of the embodiment comprises a cell assembly 40 and a housing assembly, wherein the housing assembly comprises a housing 10 and a top cover, the housing 10 and the top cover enclose a containing cavity, the containing cavity is used for containing the cell assembly 40, and the cell assembly 40 can output electric energy outwards through the housing assembly, or the cell assembly 40 can receive electric energy input from the outside through the housing assembly. The housing 10 includes a bottom wall 12 and an annular side wall 11 connected to each other, and the bottom wall 12 and the top cover are respectively located at both ends of the annular side wall 11.

The bottom wall 12 is provided with a liquid filling hole 121, and a sealing cover 14 for sealing the liquid filling hole 121 is welded to the liquid filling hole 121. On the one hand, because the diapire 12 of casing 10 is compared in that the top cap is associated the structure comparatively few, overall structure is comparatively simple and the space is bigger to not only be convenient for annotate the setting of liquid hole 121, be convenient for follow-up sealing cap 14's welding moreover is favorable to promoting sealing cap 14's welding effect, and then is favorable to promoting the yields of battery, reduces the difficulty of the manufacturing process of battery. On the other hand, since the second metal sheet 20 is usually an aluminum alloy sheet, the welding performance of the aluminum alloy is poor, and the case 10 is usually a steel case, the welding performance of the steel is good, so that the liquid injection hole 121 is disposed on the bottom wall 12 of the case 10, which is beneficial to improving the effect of the sealing cover 14 for welding and sealing the liquid injection hole 121, thereby being beneficial to reducing the leakage probability of the battery, and further being beneficial to improving the yield of the battery.

Referring to fig. 1 to 3, the outer surface of the bottom wall 12 is provided with a receiving groove 122, the liquid injection hole 121 is disposed at the bottom of the receiving groove 122, and the diameter of the liquid injection hole 121 is smaller than that of the receiving groove 122; the sealing cover 14 is located in the receiving groove 122, and the diameter of the sealing cover 14 is smaller than or equal to the diameter of the receiving groove 122 and larger than the diameter of the pour hole 121. On the one hand, the containing groove 122 can limit the sealing cap 14, so that the edge of the sealing cap 14 is uniformly overlapped on the edge of the liquid injection hole 121, and the liquid injection hole 121 is better covered and sealed. On the other hand, the sealing cover 14 is located in the containing groove 122, so that the height of the sealing cover 14 protruding out of the bottom wall 12 can be reduced, and the flatness of the appearance of the button cell is improved.

Optionally, the difference between the diameter of the receiving groove 122 and the diameter of the liquid injection hole 121 is greater than or equal to 0.5mm, and for example, the difference between the diameter of the receiving groove 122 and the diameter of the liquid injection hole 121 may be set to any value of 0.5mm, 0.7mm, 0.9mm, 1mm, 1.1mm, 1.3mm, or greater than 0.5mm according to actual needs. Thereby can avoid the diameter of storage tank 122 and annotate the difference of liquid hole 121's diameter too little to guarantee that the width of closing cap 14 overlap joint at the edge of annotating liquid hole 121 can not be too narrow, improve the reliability of the sealed liquid hole 121 that annotates of closing cap 14, and then be favorable to reducing the risk of button cell weeping, improve button cell's yields.

Optionally, the difference between the diameter of the receiving groove 122 and the diameter of the sealing cap 14 is in a range of 0.01mm-2.5mm, and for example, the difference between the diameter of the receiving groove 122 and the diameter of the sealing cap 14 may be set to any value in a range of 0.01mm, 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, or 0.01mm-2.5mm according to actual needs. On one hand, the problem that the sealing cover 14 is difficult to put into the accommodating groove 122 due to too small difference between the diameter of the accommodating groove 122 and the diameter of the sealing cover 14 is avoided; on the other hand, it is avoided that the difference between the diameter of the receiving groove 122 and the diameter of the sealing lid 14 is too large, which results in too narrow width of the sealing lid 14 overlapping the edge of the pour hole 121.

Optionally, the depth range of the accommodating groove 122 is 0.01mm to 0.15mm, and for example, the depth of the accommodating groove 122 may be set to any value within a range of 0.01mm, 0.05mm, 0.07mm, 0.09mm, 0.13mm, 0.15mm, or 0.01mm to 0.15mm according to actual needs. On one hand, the problem that the groove bottom of the accommodating groove 122 is too thin and is unfavorable for the strength of the button cell due to too large depth of the accommodating groove 122 is avoided; on the other hand, it is avoided that the depth of the receiving groove 122 is too shallow, which results in that the receiving groove 122 cannot play the purpose of limiting the protruding height of the sealing cap 14 and reducing the protruding height of the sealing cap 14, or that the effect of limiting the protruding height of the sealing cap 14 and reducing the protruding height of the receiving groove 122 is not good.

Referring to fig. 1 and 2, the cell assembly 40 may be a winding cell, the winding cell has a shaft hole in the middle, and the injection hole 121 and the projection of the shaft hole on the bottom wall 12 at least partially overlap, so as to facilitate the injection of the electrolyte from the injection hole 121, thereby facilitating the guarantee of sufficient electrolyte injected into the battery, and guaranteeing the cycle performance of the battery.

In an alternative implementation manner, the liquid injection hole 121 and the receiving groove 122 are coaxially disposed, so that whether the placement position of the sealing cap 14 meets the requirement is determined by observing the width of the gap between the edge of the sealing cap 14 and the side wall of the receiving groove 122.

In other alternative implementations, the pour hole 121 and the receiving groove 122 may be disposed in different axes, as long as the edge of the sealing cap 14 is overlapped on the edge of the pour hole 121 when the sealing cap 14 is placed.

In an optional implementation manner, the sealing cap 14 and the receiving groove 122 are coaxially disposed, so that the width of a gap between the edge of the sealing cap 14 and the side wall of the receiving groove 122 is kept uniform, thereby facilitating welding and being beneficial to ensuring that a welded seam formed after welding is uniform and beautiful.

In other optional implementation manners, the sealing cap 14 and the receiving groove 122 may also be arranged non-coaxially, as long as the sealing cap 14 can be placed in the receiving groove 122, and the welding between the sealing cap 14 and the inner wall of the receiving groove 122 is not affected.

In an optional implementation manner, the liquid injection hole 121 and the casing 10 are coaxially disposed, that is, the liquid injection hole 121 is disposed at the central position of the bottom wall 12 of the casing 10, and at this time, the liquid injection hole 121 corresponds to the cavity in the middle of the winding-type battery core, so as to facilitate the injection of the electrolyte, thereby facilitating the guarantee of the amount of the electrolyte injected into the inside of the button cell to meet the requirement, and further facilitating the guarantee of the performance of the button cell.

Referring to fig. 4 to 6, the edge of the sealing cap 14 is welded to the inner wall of the receiving groove 122 to form a first welding seam 123, the width of the first welding seam 123 ranges from 0.1mm to 1.0mm, and for example, the width of the first welding seam 123 may be any value within a range of 0.1mm, 0.3mm, 0.5mm, 0.7mm, 1.0mm, or 0.1mm to 1.0mm according to actual welding conditions. On one hand, the phenomenon that the sealing cover 14 seals the liquid injection hole 121 due to too narrow welding seams is avoided; on the other hand, the phenomenon that the appearance of the button cell is influenced by too wide welding seam is avoided. Therefore, the sealing cover 14 not only can seal the liquid filling hole 121 well, but also is beneficial to ensuring the appearance of the button cell.

Further, a gap is formed between the edge of the sealing cover 14 and the inner wall of the receiving groove 122, and the first welding seam 123 fills at least a part of the gap. Specific implementations of the first welding seam 123 for filling the gap between the edge of the sealing lid 14 and the inner wall of the receiving groove 122 include, but are not limited to, the following three implementations:

referring to fig. 4, in a first alternative implementation manner, the first weld 123 fills up a gap between the edge of the sealing cap 14 and the inner wall of the receiving groove 122, and improves the sealing performance between the sealing cap 14 and the inner wall of the receiving groove 122, so as to improve the reliability of the sealing cap 14 in sealing the injection hole 121, and further, is beneficial to improving the product yield of the button cell.

Referring to fig. 5, in a second alternative implementation manner, the first welding seam 123 fills a lower half portion of a gap between the edge of the sealing cap 14 and the inner wall of the receiving groove 122, so as to improve the sealing performance between the sealing cap 14 and the inner wall of the receiving groove 122, thereby being beneficial to improving the reliability of the sealing cap 14 in sealing the liquid injection hole 121, and further being beneficial to improving the product yield of the button cell.

Further, when the first welding seam 123 fills the lower half portion of the gap between the edge of the sealing lid 14 and the inner wall of the containing groove 122, a molten pool depression 1231 is formed on the surface of the first welding seam 123, and the depth of the molten pool depression 1231 ranges from 0.005mm to 0.05 mm. Illustratively, the depth of the weld pool depression 1231 may range anywhere from 0.005mm, 0.008mm, 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, or 0.005mm to 0.05mm, depending on the actual welding conditions.

Referring to fig. 6, in a third alternative implementation manner, a first welding seam 123 is formed between an edge of the sealing cap 14 and the bottom of the receiving groove 122, that is, the first welding seam 123 fills a corner of a gap between the edge of the sealing cap 14 and the inner wall of the receiving groove 122, which is beneficial to improving the sealing property between the sealing cap 14 and the bottom of the receiving groove 122, so as to be beneficial to improving the reliability of the sealing cap 14 in sealing the liquid injection hole 121, and further beneficial to improving the product yield of the button cell.

Optionally, the thickness of the sealing cap 14 is less than or equal to the depth of the receiving groove 122, and preferably, the thickness of the sealing cap 14 is equal to the depth of the receiving groove 122, so as to be beneficial to improving the flatness of the appearance of the button cell.

Referring to fig. 7, in an alternative implementation, the central region of the sealing cap 14 protrudes away from the liquid injection hole 121, that is, the sealing cap 14 may be formed as a curved shell with the central region arched outward, so that the edge of the sealing cap 14 is in sufficient contact with the edge of the liquid injection hole 121, thereby facilitating to improve the welding effect between the sealing cap 14 and the edge of the liquid injection hole 121, making the sealing of the sealing cap 14 to the liquid injection hole 121 more reliable, and further facilitating to improve the product yield of the button cell.

Optionally, the height range of the outer surface of sealing cover 14 protruding from the outer surface of bottom wall 12 is 0.02mm-2mm, and for example, the height range of the outer surface of sealing cover 14 protruding from the outer surface of bottom wall 12 may be set to any value within the range of 0.02mm, 0.5mm, 1mm, 1.5mm, 2mm, or 0.02mm-2mm according to actual needs. On the one hand, the height of the outer surface of the sealing cover 14 protruding out of the outer surface of the bottom wall 12 is prevented from being too low, so that the contact effect between the edge of the sealing cover 14 and the edge of the liquid injection hole 121 is not good enough; on the other hand, the outer surface of the sealing cover 14 is prevented from protruding out of the outer surface of the bottom wall 12 to a too high height, which affects the aesthetic appearance of the button cell.

Optionally, the height range of the inner surface of the sealing lid 14 protruding out of the bottom of the receiving groove 122 is 0.01mm to 0.05mm, and for example, the height of the inner surface of the sealing lid 14 protruding out of the bottom of the receiving groove 122 may be set to any value within a range of 0.01mm, 0.03mm, 0.05mm, or 0.01mm to 0.05mm according to actual needs. Thereby be favorable to increasing the volume in holding chamber to make the holding intracavity can hold more electrolyte, and then be favorable to promoting button cell's cyclicity ability. Of course, the inner surface of the flap 14 may be flush with the bottom of the receiving groove 122, which is not described in detail herein.

In other alternative implementations, the sealing cover 14 may also be a flat plate, or the shape of the sealing cover 14 may also be designed according to actual needs, as long as the requirements of the present embodiment can be met, and details are not described here.

Referring to fig. 8, one end of the hole wall of the liquid injection hole 121 close to the electric core assembly 40 may be set as a circular arc angle 124; or, the end of the hole wall of the liquid injection hole 121 far away from the electric core assembly 40 can be set to be the circular arc angle 124; alternatively, both ends of the hole wall of the liquid injection hole 121 may be set to be the circular arc angles 124.

Optionally, the radius of the arc angle 124 ranges from 0.01mm to 2mm, and for example, the radius of the arc angle 124 may be set to any value within a range of 0.01mm, 0.05mm, 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, or 0.01mm to 2mm according to actual needs. On one hand, burrs formed at two ends of the hole wall of the liquid injection hole 121 in the machining process can be removed, so that short circuit caused by the burrs falling into the accommodating cavity is prevented, and the quality and reliability of the button cell are guaranteed; on the other hand, the sharp edges formed at the two ends of the hole wall of the liquid injection hole 121 are avoided from scratching other parts.

Referring to fig. 1 to 3, the bottom end of the annular side wall 11 is connected to the circumferential edge of the bottom wall 12, and normally, the annular side wall 11 and the bottom wall 12 are formed as a single integral piece. The top end of the annular side wall 11 is connected to the outer peripheral edge of the first metal sheet 13, which may be welded or connected by other connection methods.

Referring to fig. 9, the top end of the inner wall of the annular side wall 11 is provided with an annular step groove 111, and the outer diameter of the annular step groove 111 is smaller than that of the annular side wall 11; the outer peripheral edge of the first metal sheet 13 is located in the annular step groove 111, and the annular step groove 111 can support and limit the first metal sheet 13 to facilitate the welding operation. The outer peripheral edge of the first metal sheet 13 is welded to the inner wall of the annular step groove 111 to form a second weld 112. The annular step groove 111 and the second weld 112 are advantageous not only in ensuring the reliability of the connection between the first metal sheet 13 and the annular side wall 11, but also in ensuring the sealability of the connection between the first metal sheet 13 and the annular side wall 11.

Optionally, the width of the second welding seam 112 is in a range of 0.1mm-1.0mm, and for example, the width of the second welding seam 112 may be any value in a range of 0.1mm, 0.3mm, 0.5mm, 0.7mm, 1.0mm, or 0.1mm-1.0mm according to the actual welding situation. On the one hand, the second weld seam 112 is prevented from being too narrow, reducing the welding effect and the sealing effect between the annular side wall 11 and the first metal sheet 13; on the other hand, it is avoided that the second weld 112 is too wide, which affects the appearance of the button cell.

In an alternative implementation manner, the annular side wall 11 is disposed coaxially with the annular step groove 111, and the difference between the outer diameter of the annular side wall 11 and the outer diameter of the annular step groove 111 is in a range of 0.1mm to 0.18mm, for example, the difference between the outer diameter of the annular side wall 11 and the outer diameter of the annular step groove 111 may be set to any value in a range of 0.1mm, 0.13mm, 0.15mm, 0.17mm, 0.18mm, or 0.1mm to 0.18mm according to actual needs. On one hand, the problem that the limiting effect of the annular step groove 111 on the first metal sheet 13 is influenced because the step surface at the top end of the annular side wall 11 is too narrow is avoided; on the other hand, it is avoided that the thickness of the portion of the annular step groove 111 surrounding the outer periphery of the first metal sheet 13 is too thin, affecting the welding effect between the outer peripheral edge of the first metal sheet 13 and the inner wall of the annular step groove 111, and the strength of the connection between the outer peripheral edge of the first metal sheet 13 and the inner wall of the annular step groove 111.

Optionally, the thickness of the first metal sheet 13 is equal to the depth of the annular stepped groove 111, which is not only beneficial to ensuring the welding effect between the peripheral edge of the first metal sheet 13 and the inner wall of the annular stepped groove 111, but also beneficial to ensuring the aesthetic degree of the appearance of the button cell.

Referring to fig. 9, the outer peripheral edge of the insulating seal 30 is formed with a first insulating protrusion 31 shielding the outer peripheral edge of the second metal sheet 20, and the first insulating protrusion 31 is not only advantageous for ensuring insulation between the edge of the second metal sheet 20 and the first metal sheet 13; but also to promote the sealing between the second metal sheet 20 and the first metal sheet 13.

Referring to fig. 9, the inner peripheral edge of the insulating seal member 30 is formed with a second insulating protrusion 32 that shields the inner edge of the first metal sheet 13, and the second insulating protrusion 32 is not only advantageous for ensuring insulation between the second metal sheet 20 and the inner edge of the first metal sheet 13; but also to promote the sealing between the second metal sheet 20 and the first metal sheet 13.

Referring to fig. 12 and 13, in a first alternative implementation, a first annular groove 21 may be provided on the outer surface of the second metal sheet 20, and the thickness of the groove bottom of the first annular groove 21 is smaller than that of the second metal sheet 20; alternatively, the first annular groove 21 may be provided on the inner surface of the second metal sheet 20, and the thickness of the groove bottom of the first annular groove 21 is smaller than that of the second metal sheet 20. First annular groove 21 can play the explosion-proof effect of pressure release when the inside pressure of battery risees to be favorable to avoiding the battery explosion to cause serious harm.

In a second alternative implementation, a second annular groove may be provided on the outer surface of bottom wall 12, the thickness of the groove bottom of the second annular groove being smaller than the thickness of bottom wall 12; alternatively, a second annular groove may be provided on the inner surface of the bottom wall 12, the groove bottom of the second annular groove having a thickness smaller than the thickness of the bottom wall 12. The second annular groove can play the explosion-proof effect of pressure release when the inside pressure of battery risees to be favorable to avoiding the battery explosion to cause serious harm.

It can be understood that, when the second metal sheet 20 is an aluminum alloy sheet and the housing 10 is a steel housing 10, the pressure relief and explosion prevention effect of the first annular groove 21 provided on the aluminum alloy sheet is better, and therefore, the first implementation manner is a preferable scheme among the two implementation manners.

It should be noted that, the inner surface of the second metal sheet 20 or the inner surface of the bottom wall 12 refers to a side surface facing the accommodating cavity, and the outer surface of the second metal sheet 20 or the outer surface of the bottom wall 12 refers to a side surface facing away from the accommodating cavity.

Referring to fig. 11, alternatively, the first annular groove 21 includes a first outer ring groove 211 and a first inner ring groove 212, the first inner ring groove 212 is disposed at the groove bottom of the first outer ring groove 211, and the notch width of the first inner ring groove 212 is smaller than the notch width of the first outer ring groove 211. Because the groove bottom thickness of the first inner ring groove 212 is smaller, the groove bottom thickness is more sensitive to the air pressure rise inside the button cell, and therefore the pressure relief and explosion prevention effects can be better achieved.

Optionally, the second annular groove includes a second outer ring groove and a second inner ring groove, the second inner ring groove is disposed at a bottom of the second outer ring groove, and a width of the notch of the second inner ring groove is smaller than a width of the notch of the second outer ring groove. Because the groove bottom thickness of the second inner ring groove is smaller, the groove bottom thickness is more sensitive to the air pressure rise inside the battery, and therefore the pressure relief and explosion prevention effects can be better achieved.

Optionally, the minimum thickness of the groove bottom of the first annular groove 21 ranges from 0.02mm to 0.1mm, and for example, when the first annular groove 21 has the shape shown in fig. 10, the thickness of the groove bottom of the first annular groove 21 is the minimum thickness; when the first annular groove 21 has the shape shown in fig. 11, the groove bottom thickness of the first inner annular groove 212 is the minimum thickness at this time. Illustratively, the minimum thickness of the groove bottom of the first annular groove 21 may be set to any value within a range of 0.02mm, 0.04mm, 0.06mm, 0.08mm, 0.1mm, or 0.02mm to 0.1mm according to actual needs. On one hand, the minimum thickness of the groove bottom of the first annular groove 21 is prevented from being too small, so that the pressure born by the shell of the button cell is reduced too much; on the other hand, the minimum thickness of the groove bottom of the first annular groove 21 is prevented from being too large, so that the pressure relief and explosion prevention effects are not good.

Optionally, the first annular groove 21 is coaxial with the housing 10, so as to perform uniform pressure relief when the internal pressure of the button cell is too high, thereby achieving a better pressure relief and explosion prevention effect.

Optionally, the second annular groove is coaxial with the housing 10, so as to perform uniform pressure relief when the internal pressure of the button cell is too high, thereby achieving a better pressure relief and explosion prevention effect.

Referring to fig. 1, the second tab 41 is optionally welded to the bottom wall 12 of the casing 10 to form at least one weld 412, and the second tab 41 and the bottom wall 12 of the casing 10 may be welded, for example, by resistance welding or laser welding. In order to prevent the soldering prints 412 on the side of the second pole lug 41 facing the electric core assembly 40 from scratching the electric core assembly 40, a second pole lug protective adhesive 411 can be arranged on the side of the second pole lug 41 facing the electric core assembly 40, and the second pole lug protective adhesive 411 covers the soldering prints 412, so that on one hand, the second pole lug protective adhesive 411 can avoid the adverse effect of the soldering prints 412 on the electric core assembly 40; on the other hand, the second tab protection glue 411 can provide a certain heat insulation effect when the second tab 41 is welded, and prevent the electric core assembly 40 from being damaged by high welding temperature.

After the second tab 41 is welded to the bottom wall 12, no other welding mark is formed on the outer surface of the bottom wall 12 in the area corresponding to the welding mark 412, thereby being beneficial to ensuring the smoothness of the outer surface of the battery.

In order to protect the first tab 42 and the second tab 41 and avoid short circuit between the tabs and the pole piece and the housing, a first tab protection adhesive 421 may be disposed on both side surfaces of the first tab 42, and a second tab protection adhesive 411 may be disposed on both side surfaces of the second tab 41.

Optionally, a first insulating glue layer 43 is disposed between the first end face of the electric core assembly 40 and the bottom wall 12, and the first insulating glue layer 43 is used for preventing a short circuit between the electric core assembly 40 and the casing 10. A portion of the first insulation adhesive layer 43 is located between the second tab protection adhesive 411 and the first end surface of the electric core assembly 40, and a portion of the first insulation adhesive layer 43 covers the second tab protection adhesive 411 at a position corresponding to the solder mark 412. At this time, two glue layers are interposed between the solder print 412 of the second tab 41 and the electric core assembly 40, one is a second tab protective glue 411 arranged on one side of the second tab 41 facing the electric core assembly 40, and the other is a first insulating glue layer 43 arranged between the electric core assembly 40 and the second tab 41, and the two glue layers can better isolate the solder print 412 on the second tab 41 from the electric core assembly 40, so that on one hand, the solder print 412 is prevented from penetrating through the glue layers to have adverse effects on the electric core assembly 40; on the other hand, the electric core assembly 40 is prevented from being damaged by high welding temperature.

It can be understood that a second insulating adhesive layer 44 can be disposed between the second end surface of the cell assembly 40 and the top cap, and the second insulating adhesive layer 44 is used for preventing a short circuit between the cell assembly 40 and the top cap 10, thereby being beneficial to ensuring the reliability and safety of the battery.

The processing and manufacturing process of the battery of the embodiment comprises the following steps: cutting the second pole lug 41 of the electric core assembly 40 to a fixed length and then bending the second pole lug 41, wherein the bent second pole lug 41 is parallel to the end face of the electric core assembly 40; placing the electric core assembly 40 in the accommodating cavity of the shell 10; the second tab 41 of the electric core assembly 40 is welded with the shell 10 by laser welding or resistance welding; welding the second metal sheet 20 of the top cover with the first tab 42 of the electric core assembly 40; after the top cover is turned over, the first metal sheet 13 of the top cover extends into the annular step groove 111 at the top end of the shell 10; the first metal sheet 13 of the top cover is welded and connected with the shell 10 by laser welding; after the steps are finished, putting the semi-finished battery into an oven for baking; injecting electrolyte through a through hole at the bottom of the shell 10 after baking; after the electrolyte is injected, the sealing cover 14 is placed in the accommodating groove 122 at the bottom of the shell 10, and the sealing cover 14 and the shell 10 are welded and connected through laser welding; and (5) after the steps are completed, carrying out electrical property test. Thereby completing the manufacture of the battery.

In the description of the present invention, it is to be understood that the terms "top," "bottom," "upper," "lower" (if present), and the like, are used in the orientation or positional relationship shown in the drawings for convenience in describing the present invention and to simplify the description, and are not intended to indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The terms "first" and "second" in the description and claims of the present application and the description of the above-described figures are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. A battery comprises a battery core assembly and an outer casing assembly, wherein the outer casing assembly comprises a shell and a top cover, the shell and the top cover enclose a containing cavity, and the containing cavity is used for containing the battery core assembly;

the shell comprises a bottom wall and an annular side wall which are connected with each other, and the bottom wall and the top cover are respectively positioned at two ends of the annular side wall;

be provided with on the diapire and annotate the liquid hole, it has the welding to annotate the welding of liquid hole department seal closure in annotating the liquid hole.

2. The battery of claim 1, wherein the top cover comprises a first metal sheet having a through hole, an insulating seal member, and a second metal sheet, the first metal sheet being connected to one end of the annular side wall, the second metal sheet being connected to the first metal sheet through the insulating seal member and covering the through hole;

the battery pack assembly is provided with a first tab and a second tab, the first tab is opposite to the second tab in electrical property, the first tab is connected with the second metal sheet, and the second tab is connected with the shell or the first metal sheet.

3. The battery according to claim 2, wherein the outer surface of the bottom wall is provided with a receiving groove, the liquid injection hole is arranged at the bottom of the receiving groove, and the diameter of the liquid injection hole is smaller than that of the receiving groove;

the sealing cover is located in the containing groove, and the diameter of the sealing cover is smaller than or equal to that of the containing groove and larger than that of the liquid injection hole.

4. The battery according to claim 3, wherein the difference between the diameter of the container and the diameter of the liquid injection hole is greater than or equal to 0.05 mm; and/or the presence of a gas in the gas,

the difference range of the diameter of the accommodating groove and the diameter of the sealing cover is 0.01mm-2.5 mm; and/or the presence of a gas in the gas,

the depth range of the accommodating groove is 0.01mm-0.15 mm.

5. The battery according to claim 3, wherein the core assembly is a winding type cell, the winding type cell has a shaft hole in the middle, and the liquid injection hole at least partially overlaps with the projection of the shaft hole on the bottom wall.

6. The battery of claim 3, wherein an edge of the cover is welded to an inner wall of the container and forms a first weld.

7. The battery of claim 6, wherein a gap is provided between an edge of the cover and an inner wall of the container, and the first weld fills at least a portion of the gap.

8. The battery of claim 6, wherein a surface of the first weld is formed with a puddle depression, the puddle depression having a depth in a range of 0.005mm-0.05 mm.

9. The battery of claim 3, wherein the thickness of the flap is less than or equal to the depth of the receiving groove.

10. The battery according to claim 3, wherein the central region of the lid is convex toward a direction away from the pour hole;

the height range of the outer surface of the sealing cover protruding out of the outer surface of the bottom wall is 0.02mm-2 mm; and/or the height range of the inner surface of the sealing cover protruding out of the bottom of the containing groove is 0.01mm-0.05 mm.

11. The battery as claimed in any one of claims 2 to 10, wherein one end of the hole wall of the liquid injection hole close to the battery cell assembly is provided with a circular arc angle; and/or the presence of a gas in the gas,

one end of the hole wall of the liquid injection hole, which is far away from the electric core assembly, is set to be an arc angle;

the shell is a steel shell, and the second metal sheet is an aluminum alloy sheet.

12. The battery according to any one of claims 2 to 10, wherein the top end of the inner wall of the annular side wall is provided with an annular step groove, and the outer diameter of the annular step groove is smaller than that of the annular side wall;

the peripheral edge of the first metal sheet is located in the annular step groove, and the peripheral edge of the first metal sheet is connected with the inner wall of the annular step groove in a welding mode to form a second welding line.

13. The cell defined in claim 12, wherein the annular side wall is disposed coaxially with the annular step groove, and the difference between the outer diameter of the annular side wall and the outer diameter of the annular step groove is in the range of 0.1mm to 0.18 mm.

14. The battery according to any one of claims 2 to 10, wherein a peripheral edge of the insulating seal member is formed with a first insulating projection that shields a peripheral edge of the second metal sheet; and/or the presence of a gas in the gas,

the inner peripheral edge of the insulating seal member is formed with a second insulating protrusion that shields the inner edge of the first metal sheet.

15. The battery of any one of claims 2-10, wherein the outer or inner surface of the second metal sheet is provided with a first annular groove having a groove bottom thickness that is less than the thickness of the second metal sheet; and/or the presence of a gas in the gas,

and a second annular groove is formed in the outer surface or the inner surface of the bottom wall, and the thickness of the groove bottom of the second annular groove is smaller than that of the bottom wall.

16. The battery of claim 15, wherein the first annular groove comprises a first outer ring groove and a first inner ring groove, the first inner ring groove disposed at a groove bottom of the first outer ring groove, and a notch width of the first inner ring groove is less than a notch width of the first outer ring groove; and/or the presence of a gas in the gas,

the second annular groove comprises a second outer ring groove and a second inner ring groove, the second inner ring groove is arranged at the bottom of the second outer ring groove, and the width of the notch of the second inner ring groove is smaller than that of the first outer ring groove.

17. The cell defined in claim 15, wherein the minimum thickness of the groove bottom of the first annular groove is in the range of 0.02mm to 0.1 mm.

18. The battery of claim 15, wherein the first annular groove is disposed coaxially with the housing; and/or the presence of a gas in the gas,

the second annular groove is disposed coaxially with the housing.

19. The battery of any of claims 2-10, wherein the second tab is welded to the base wall and forms at least one weld impression; one side, facing the electric core component, of each second electrode lug is provided with second electrode lug protective glue, and the second electrode lug protective glue covers the welding seal;

and the area of the outer surface of the bottom wall corresponding to the welding mark is free of welding mark.

20. The battery of claim 19, wherein a first insulating glue layer is disposed between the first end surface of the cell assembly and the bottom wall, a portion of the first insulating glue layer is located between the second tab protecting glue and the first end surface of the cell assembly, and a portion of the first insulating glue layer covers a position of the second tab protecting glue corresponding to the solder print.