CN111009624B

CN111009624B - Button cell and electronic device

Info

Publication number: CN111009624B
Application number: CN201911072196.4A
Authority: CN
Inventors: 陈志勇
Original assignee: Guangdong Mic Power New Energy Co Ltd
Current assignee: Guangdong Mic Power New Energy Co Ltd
Priority date: 2019-11-05
Filing date: 2019-11-05
Publication date: 2021-07-13
Anticipated expiration: 2039-11-05
Also published as: CN111009624A

Abstract

The invention discloses a button battery and an electronic device. The battery includes: an electric core; at least one tab, one end of at least one of the tabs is connected to a current collector of the electric core; a shell, the shell includes a first shell and a second shell, the first shell A shell is sealingly connected with the second shell to surround and form a cavity, the battery core and the tab are located in the cavity, and the other end of at least one of the tabs is welded to the first shell. On the inner wall or the inner wall of the second shell, the welding bead or welding point spreads outward from the part where the tab contacts the inner wall of the first shell, or is formed by the contact between the tab and the second shell. The part where the inner wall contacts spreads outward.

Description

Button cell and electronic device

Technical Field

The invention relates to the technical field of energy storage devices, in particular to a button battery and electronic equipment.

Background

Button cells, especially rechargeable button cells, are widely used in electronic products due to their small size. Such as wireless headsets, electronic watches, and the like. In the assembly process of the button cell, an electrode of a battery cell needs to be welded on a shell through a tab.

In assembly, one end of the tab is first welded to the cell, for example, to a current collector of the cell. Then, the battery core and the pole lug are placed in the shell, and the other end of the pole lug needs to be aligned to a set position of the inner wall of the shell. Next, the housing is hermetically connected. And finally, welding the other end of the lug to the inner wall of the shell by a welding point penetrating through the shell from the outer side of the shell in a laser welding mode.

However, in this assembly method, the case is assembled and then the tab is welded to the case. Because the casing has closed, so can't judge whether the other end of utmost point ear is fixed for predetermined position when carrying out laser welding to can't detect welded quality, lead to button cell's yields lower.

Therefore, a new technical solution is needed to solve at least one of the above technical problems.

Disclosure of Invention

The invention aims to provide a novel technical scheme of a button battery.

According to a first aspect of the invention, a button cell is provided. The battery includes: an electric core; one end of at least one tab is connected with one current collector of the battery core; a housing, the casing includes first shell and second shell, first shell with second shell sealing connection to surround and form the cavity, electric core with utmost point ear is located in the cavity, at least one the other end of utmost point ear is welded to on the inner wall of first shell perhaps on the inner wall of second shell, welding bead or solder joint by utmost point ear with the position outdiffusion of the inner wall contact of first shell, perhaps by utmost point ear with the position outdiffusion of the inner wall contact of second shell.

Optionally, the welding is performed before or after the first and second housings are hermetically connected.

Alternatively, the other end of the tab is coupled to the inner wall of the first case or the inner wall of the second case by welding through the tab by a welding point.

Optionally, at least one of the first housing and the second housing includes a top portion and a sidewall portion, the sidewall portion is disposed around and connected to an edge of the top portion, the other end of the tab is welded to the top portion, and the top portion is in a concave arc structure or a convex arc structure.

Optionally, the first housing and the second housing each include a top portion and a side wall portion connected together, the first housing and the second housing are snap-fit connected with an open end facing each other, an annular sealing member is disposed between the two side wall portions, an edge of the annular sealing member is in a V-shaped configuration, the annular sealing member is sleeved outside one of the side wall portions, and an edge of the side wall portion extends into the V-shaped configuration.

Alternatively, the mouth edge of the side wall portion on the outer side is entirely shrunk inward to press the annular seal.

Optionally, a part of the mouth edge of the outer side wall portion projects inwardly to form a mouth.

Optionally, the plurality of the inlets is uniformly distributed on the edge of the sidewall.

Alternatively, the side wall portion on the inner side forms an annular constriction at a location corresponding to the mouth edge, the mouth edge being curved towards the annular constriction.

Optionally, the edge of the inner side wall portion at the open end has an annular projection projecting outward.

Alternatively, sealing portions may be formed at the open end of the first housing and the open end of the second housing, a portion of the two side wall portions between the two sealing portions may be spaced, a thickness of the annular seal at the two open ends may be greater than a thickness of a middle portion in the axial direction, and one end of the annular seal having the greater thickness may form the V-shaped structure.

Optionally, the annular seal is injection molded.

Optionally, the tab includes welding regions at both ends, and an area of the tab outside the welding regions is covered with an insulating material.

Optionally, the welding pin is located outside or inside the housing and abuts against the housing when welding is performed.

According to another embodiment of the present disclosure, an electronic device is provided. The electronic equipment comprises the button battery.

According to one embodiment of the present disclosure, the welding precision of the tab and the housing is high.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a cross-sectional view of a button cell according to one embodiment of the present disclosure.

Fig. 2 is a partially enlarged view of a portion a in fig. 1.

Fig. 3 is a partially enlarged view at B in fig. 1.

Fig. 4 is a partially enlarged view at C in fig. 1.

Fig. 5 is a cross-sectional view of another first housing according to one embodiment of the present disclosure.

Fig. 6 is a cross-sectional view of yet another first housing according to an embodiment of the present disclosure.

FIG. 7 is a cross-sectional view of an annular seal according to one embodiment of the present disclosure.

FIG. 8 is a schematic view of a welding mode according to one embodiment of the present disclosure.

11: a first housing; 12: a second housing; 13: an electric core; 141: a first tab; 142: a second tab; 15: an annular seal; 151: a V-shaped structure; 152: an end portion; 101: an annular bend; 102: a closing-in part; 103: a second top portion; 104: an annular projection; 105: a first side wall portion; 106: a second side wall portion; 107: an annular constriction; 108: sealing glue; 109: a first top portion; 16: a weld bead or spot; 17: and (7) welding pins.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

According to one embodiment of the present disclosure, a button cell is provided. As shown in fig. 1, the button cell battery includes a case, a battery cell 13, and at least one tab.

The battery cell 13 is used for converting electric energy and chemical energy and/or chemical energy and electric energy. For example, the positive electrode material of the battery cell 13 includes a lithium-containing compound, such as lithium cobaltate, lithium iron phosphate, or a ternary system material. The negative electrode material of the cell 13 includes graphite. The two electrode materials are respectively attached to different current collectors. The current collector is a metal foil. An ion exchange membrane is arranged between the anode material and the cathode material. Lithium ions can pass through the ion exchange membrane, but other materials such as graphite cannot pass through the membrane. For example, the battery cell 13 has a winding structure or a laminated structure.

The housing includes a first shell 11 and a second shell 12. The first housing 11 is hermetically connected with the second housing 12 to form a cavity. An annular seal 15 is provided between the first housing 11 and the second housing 12 to insulate the first housing 11 from the second housing 12. The annular seal 15 is made of an insulating material, such as plastic or rubber.

For example, the ring-shaped seal 15 protrudes at the edge of the gap formed by the first and second housings 11 and 12 so as to be filled in the gap. In this way, external dust, rain, sweat, and the like do not accumulate in the gap, and thus corrosion of the first and second housings 11 and 12 due to accumulation of foreign matter can be avoided.

The battery cell 13 and the electrode lug are positioned in the cavity. The utmost point ear is provided with at least one. One end of the tab is connected to a current collector of the cell 13. The other end of the tab is connected with the shell. In the battery cell 13 of the wound structure, the tabs include a first tab 141 and a second tab 142. For example, the first tab 141 is used to connect the positive electrode collector with one of the cases, for example, the second case 12; the second tab 142 is used to connect the negative electrode collector with another case, for example, the first case 11.

The first tab 141 may be used to connect the negative electrode collector and the first case 11; the second tab 142 is used to connect the positive electrode collector with the second case 12.

For example, in assembly, first, one end of at least one tab is connected to a positive electrode collector or a negative electrode collector. The cell 13 and tab are then placed together into the cavity.

In the disclosed embodiment, the other end of at least one of the tabs is welded to the inner wall of the first housing 11 or the inner wall of the second housing 12. For example, before the first and second housings 11 and 12 are assembled together to form a case or after the case is formed, one end of at least one tab is first welded to the inner wall of the first housing 11 or the inner wall of the second housing 12. For example, resistance welding or the like is employed.

The weld bead or the weld spot 16 is formed by outward diffusion of the contact position between the tab and the inner wall of the first housing 11, or outward diffusion of the contact position between the tab and the inner wall of the second housing 12.

For example, as shown in fig. 8, during welding, the welding pins 17 are located outside the housing. The soldering pins abut against the housing, for example, the outside of the first top 109 or the second top 103. Since the two are in contact with each other and held against each other, the resistance between the two is small, and electrical connection can be made, so that no weld bead or spot is formed at the contact portion of the pin 17 and the housing. The resistance is large at the point where the tab contacts the housing (e.g., the first tab 141 and the first top portion 109, or the second tab 142 and the second top portion 103). The current generates a large amount of heat at this location to melt the metal on both sides of the interface to form a weld bead or spot 16. As the heat builds up, the bead or weld 16 gradually diffuses outwardly from the interface, forming a larger molten zone. Thus, the tab and the case are welded together after cooling. Compared with a welding mode that welding points penetrate through the pole lugs or the shell, the welding mode has higher welding strength.

In addition, the welding mode can not form a pit on the surface of the shell or the lug opposite to the weld bead or the welding spot 16, so that the structural integrity of the welded button battery is kept, and the appearance is good.

In addition, by controlling the magnitude of the welding current, it is possible to prevent the weld bead or spot weld from extending to the outer surface of the case (e.g., the first case 11, the second case 12) or the tab, i.e., from welding through the case or the tab. Thus, the welding has little effect on the structural strength of the housing or the tab.

Of course, the welding pin may also be located inside the housing, i.e. on the side of the tab, during welding.

In one example, the welding is performed before the first and second housings are hermetically connected, the welding process can be observed since the case is not yet closed, and the effect of the welding is easily checked. Therefore, the position of the welding gun is easy to position, and the welding position on the shell is easy to position, so that the welding precision of the lug and the shell is higher.

In addition, the mode can effectively reduce poor welding and avoid the phenomenon that the electrode lug is not welded on the shell.

In another example, the welding is performed after the first housing and the second housing are hermetically connected. The mode can reduce the manufacturing difficulty of the button cell and improve the automatic production degree.

In one example, the other ends of the tabs are pre-fixed to the inner wall of the first housing 11 or the inner wall of the second housing 12 before welding. The pre-fixing means may be, but is not limited to, adhesive, snap-fit, etc. One end portion of the tab is bonded to the inner wall of either one of the housings, for example, by an adhesive, double-sided tape, or the like. In the welding process, the adhesive and the double-sided adhesive can be melted off under the action of high temperature, and no residue is generated. By pre-fixing the tabs on the inner wall of the housing, the welding position can be more accurate.

In one example, as shown in fig. 1, 5, and 6, at least one of the first housing 11 and the second housing 12 includes a top portion and a sidewall portion. The sidewall portion is disposed around and connected to an edge of the top portion. The other end of the tab is welded with the top. For example, one end of the tab is welded to the top of the first housing 11 or the second housing 12 in the above-described welding manner. The top is of an inwards concave cambered surface structure or an outwards convex cambered surface structure. The two cambered surface structures enable the top part to have a larger area, so that the tab is easier to weld.

In addition, the concave cambered surface structure has a buffering function. After the assembly is finished, the button cell is subjected to processes of liquid injection, formation, capacity grading and the like. During this process, gas is generated in the chamber, causing the internal pressure to rise. If the top is flat, bulging of the top may result due to the increase in internal pressure. The concave cambered surface enables the top to be gradually flattened in the internal pressure rising process, so that the deformation of the shell caused by the internal pressure rising is buffered, and the regular shape of the shell is kept.

In addition, the convex cambered surface can reduce the stress concentration of the edge of the top part, and the structural strength of the top part is improved. In the process of increasing the internal pressure, the convex cambered surface has higher structural strength relative to the top of the plane, so that the convex cambered surface is not easy to deform.

In other examples, the tab may also be connected to the sidewall portion.

In one example, as shown in fig. 1 and 4, the first housing 11 and the second housing 12 each include a top portion and a sidewall portion that are coupled together. For example, the first housing 11 includes a first top 109 and a first sidewall 105; the second housing 12 includes a second top portion 103 and a second sidewall portion 106. Two shells all are one end and seal, the open tubular structure of the other end. For example, the first housing 11 includes a first side wall portion 105 and a second side wall portion 106, and the first housing 11 and the second housing 12 are snap-fit connected in an open-end-to-end manner. An annular seal 15 is provided between the two side wall portions. One edge of the annular seal 15 is in a V-shaped configuration 151 as shown in figure 7. The annular seal 15 is fitted over one of the side wall portions (e.g., first side wall portion 105) and the edge of that side wall portion extends into the V-shaped structure 151 and forms a compression.

For example, as shown in FIG. 4, the edge of the first sidewall portion 105 presses the V-shaped structure 151. The first side wall portion 105 extends axially into the V-shaped structure 151 by a dimension L4, and the V-shaped structure has a remaining dimension L5 in the axial direction. Wherein, L4 is more than L5 and less than or equal to 0.5 mm. Within this size range, the sealing effect is good there, and the V-shaped structure 151 can maintain sufficient structural strength without being damaged.

In this example, the V-shaped structure 151 can effectively wrap around the open end of the first sidewall portion 105, thereby forming an L-shaped sealing edge. In this way, the sealing effect between the two housings is better.

For example, the sealing compound 108 is applied to the outside of the sealing edge of the L-shape. The sealant 108 can fill the gap between the second housing 12 and the annular sealing member 15 at the corner, so that the sealing effect of the two housings is good.

In one example, as shown in fig. 1, sealing portions are formed at the open end of the first housing 11 and the open end of the second housing 12, respectively, portions of the two side wall portions between the two sealing portions are spaced, the thickness of the annular seal 15 at the two open ends is larger than that at the middle portion in the axial direction, and one end of the annular seal 15 at which the thickness is larger forms the V-shaped structure. The first housing 11 and the second housing 12 are pressed against each other at the two open ends by means of a rolling process, for example, to form two strip-like annular seals.

In this example, the housing forms two strip-shaped annular seals, and the pressing force of the strip-shaped annular seals is larger than that of a method in which the first side wall portion 105 and the second side wall portion 106 are integrally surface-sealed at the overlapping portion, which makes the sealing effect of the two housings more excellent.

Further, in a portion between the two strip-shaped annular seals, the first side wall portion 105 and the second side wall portion 106 are spaced apart from each other with a space therebetween. The space forms a buffer space. Thus, even if the first side wall portion 105 and the second side wall portion 106 are locally deformed in the spaced region, the sealing of the case is not affected.

Further, the thickness of the annular seal 15 at both seals is larger than that at the axial middle thereof. As shown by end 152 and V-shaped structure 151 in fig. 7. Through the arrangement, when the thicker part is extruded by the two shells, larger elastic deformation can occur, so that the sealing effect of the shell is better.

Further, one end of the annular seal member 15, which has a larger thickness, is formed into a V-shaped structure 151. The V-shaped structure 151 has a greater thickness near the open end of the second housing, which results in a better seal between the V-shaped structure 151 and the two housings.

In one example, the annular seal 15 is injection molded. Thus, the V-shaped structure 151 is formed by injection molding, rather than being formed by first leaving a portion of the housing during assembly and then bending the housing inward. The dimensional accuracy and the processing consistency of the V-shaped structure 151 can be guaranteed through injection molding.

In one example, as shown in fig. 1-2, the open end of the outside sidewall portion is entirely shrunk inward to press the annular seal 15. For example, the open end of the second side wall portion 106 is contracted inward to form the annular bent portion 101. The annular bend 101 is capable of exerting a circumferential pressure on the annular seal 15, thereby forming a strip-shaped annular seal. In this way, the sealing effect of the first housing 11 and the second housing 12 is good.

For example, the bending dimension L1 of the annular bent part 101 is less than or equal to 0.5 mm. The sealing effect of the shell in the size range is good.

In one example, as shown in fig. 1 and 3, a portion of the open end of the outer side wall portion (e.g., the second side wall portion 106) projects inward to form the mouth 102. For example, a part of the annular bent portion 101 protrudes inward to form the receiving portion 102. For example, the plurality of the closing-in portions 102 are uniformly distributed at the opening end of the side wall portion (for example, the second side wall portion 106). The binding force of the first housing 11 and the second housing 12 is larger and the integrity of the housing is better by the receiving portion 102.

For example, the bending dimension L2 of the mouth part 102 is less than or equal to 1mm, and L1 < L2. In this size range, the first housing 11 and the second housing 12 are well connected.

In other examples, only one of the necking portions 102 may be provided.

In one example, as shown in fig. 1-2, the inner sidewall portion (e.g., first sidewall portion 105) forms an annular constriction 107 at a location corresponding to an open end of the outer sidewall portion (e.g., second sidewall portion 106). The open end is bent towards the annular constriction 107. The annular constriction 107 is an inwardly converging annular ramp. In this example, the annular seal 15 is pressed between the annular bent portion 101 and the annular slope. The annular inclined surface has a larger contact area with the annular bent portion 101 than a vertical surface, which makes the sealing effect at this point more favorable.

Furthermore, the annular constriction 107 makes the snap-fitting of the two shells even more secure.

In one example, the inside diameter of the sidewall portion (e.g., the first sidewall portion 105) located inside of the two sidewall portions is configured to gradually increase from the top toward the open end. For example, the inside diameter of the side wall portion may increase linearly or partially in a step shape. The cell 13 is easily fitted into the cavity because the inner diameter of the open end is maximized.

In one example, as shown in fig. 4 and 5, the edge of the side wall portion (e.g., the first side wall portion 105) located on the inner side at the open end has an annular protrusion 104 protruding outward. When sealing is performed, the sidewall portion (e.g., the second sidewall portion 106) located at the outside may be squeezed at a position corresponding to the annular protrusion 104. The annular protrusion 104 is closer to the outside sidewall portion (e.g., the second sidewall portion 106) so that a seal is more easily formed with the housing and the sealing effect is better.

For example, as shown in FIG. 4, the annular protrusion 104 radially compresses the annular seal. In this way, the annular sealing member 15 forms a pressure concentration zone at the portion where it is pressed, so that the sealing effect between the annular sealing member 15 and the outer housing (e.g., the second housing 12) is better.

In one example, the tab includes weld zones at both ends. One of the welding areas is welded to a current collector of the cell 13, and the other welding area is welded to the casing. The two welding areas are respectively positioned on two opposite surfaces. And the region outside the welding region of the tab is covered with an insulating material. The insulating material is, for example, an insulating film or an insulating coating. The insulating material is made of plastic, glass fiber, rubber, silica gel and the like. The insulating material can effectively avoid the contact between the lug and the end part of the battery cell 13, and prevent the short circuit of the battery cell 13.

In addition, since the case does not need to reserve a space for the tab to be spaced apart from the end of the battery cell 13, the battery cell 13 can be made larger. In this way, the capacity of the battery can be significantly increased.

According to another embodiment of the present disclosure, an electronic device is provided. The electronic device may be, but is not limited to, an earphone, a mobile phone, a laptop computer, a hearing aid, a VR device, an AR device, an electronic watch, a game console, and the like. The electronic equipment comprises the button battery.

The electronic equipment has the characteristic of good safety performance.

Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A button battery, characterized in that: comprising:

Batteries;

at least one tab, one end of at least one tab is connected to a current collector of the battery;

a casing, the casing includes a first casing and a second casing, the first casing is sealed with the second casing to form a cavity, and the battery core and the tab are located in the cavity , the other end of at least one of the tabs is welded to the inner wall of the first shell or the inner wall of the second shell, and the welding bead or welding point is in contact with the inner wall of the first shell by the tab The part spreads outward, or spreads outward from the part where the tab contacts the inner wall of the second shell;

The first shell and the second shell each include a top and side wall portions that are connected together, and the first shell and the second shell are snap-fitted and connected in a manner that the open ends are opposite to each other, on the two sides. An annular seal is arranged between the wall parts, one edge of the annular seal has a V-shaped structure, the annular seal is sleeved outside one of the side wall parts, and the edge of the side wall part has a V-shaped structure. Protruding into the V-shaped structure, the edge of the side wall portion squeezes the V-shaped structure, the size of the side wall portion extending into the V-shaped structure in the axial direction is L4, and the V-shaped structure is axially The remaining size is L5, where L4<L5≤0.5mm;

The top is in the form of a concave cambered surface structure or an outwardly convex cambered surface structure as a whole.

2 . The button battery according to claim 1 , wherein welding is performed before or after the first shell and the second shell are sealed and connected. 3 .

3. The button battery of claim 1, wherein at least one of the first housing and the second housing comprises a top and a side wall portion, the side wall portion being disposed around an edge of the top And it is connected with the edge of the top, and the other end of the tab is welded and connected with the top.

4 . The button battery according to claim 1 , wherein the edge of the mouth portion of the outer side wall portion shrinks inward as a whole to squeeze the annular sealing member. 5 .

5 . The button battery according to claim 4 , wherein a portion of the edge of the mouth of the outer side wall portion protrudes inward to form a closed portion. 6 .

6 . The button battery according to claim 5 , wherein there are a plurality of the closing portions and are evenly distributed on the edge of the side wall portion. 7 .

7 . The button battery according to claim 5 , wherein the inner side wall portion forms an annular constriction at a position corresponding to the edge of the mouth, and the edge of the mouth is bent toward the annular constriction. 8 . .

8 . The button battery according to claim 1 , wherein the edge of the inner side wall portion at the opening end has an annular protrusion protruding outward. 9 .

9 . The button battery according to claim 1 , wherein sealing parts are respectively formed at the open end of the first casing and the open end of the second casing, and the two side wall parts are located at the two side walls. 10 . The part between each of the sealing parts is spaced, the thickness of the annular seal located at the two open ends is greater than the thickness of the middle part in the axial direction, and the thickness of the annular seal is larger One of the ends forms the V-shaped structure.

10. The button battery according to any one of claims 1-9, wherein the annular seal is injection molded.

11 . The button battery according to claim 1 , wherein the tabs comprise welding areas located at both ends, and the areas outside the welding areas of the tabs are covered with insulating materials. 12 .

12 . The button battery according to claim 1 , wherein, during welding, the welding pins are located on the outer side or the inner side of the casing and are in contact with the casing. 13 .

13. An electronic device, characterized in that it comprises the button battery according to any one of claims 1-12.