Button battery and manufacturing method thereof

Abstract

The present invention relates to the technical field of lithium-ion batteries, and in particular to a button battery comprising a wound electrode group, a combined shell, and a cover plate. The wound electrode group is located within the combined shell, which is folded and connected to the cover plate and sealed. The combined shell comprises a shell, a through-hole tube, and an integrated circuit device. The shell and the through-hole tube are integrally formed, and the through-hole tube and the shell are coaxial. A positive terminal, a negative terminal, and a protective plate are welded to the ends of the integrated circuit device. The integrated circuit device passes through the through-hole tube, and the positive and negative terminals at the ends extend into the battery and are connected to the positive and negative ears of the wound electrode group. The protective plate extends to the outside of the battery, and the integrated circuit device is connected to the through-hole tube and sealed with a sealant. The wound electrode group is located within the combined shell, and the through-hole tube is inserted into the center hole of the wound electrode group. The inner wall of the combined shell provides insulation, which can reduce the use of insulating gaskets and further improve the internal space utilization of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of button batteries, and in particular to a button battery and a manufacturing method thereof. Background Art

[0002] Due to their small size, with a diameter generally no greater than 30mm and a thickness no greater than 8mm, button batteries have been widely used in various microelectronic products, generally serving as backup power sources for electronic products such as Bluetooth headsets, electronic watches, electronic scales, remote controls, cameras, pacemakers, and counters. To adapt to the trend of miniaturization, lightweighting, and thinning of electronic products, their power supply batteries are required to have a high volume-to-energy ratio. Therefore, within a limited volume, it is necessary to maximize the space occupied by effective substances inside the battery. Currently, in order to ensure the sealing performance of the battery, insulating sealing gaskets or multi-layer shell walls are often used for packaging. In the existing form, non-effective substances still occupy a large amount of internal space in the battery. Moreover, in the production of button batteries, due to volume constraints, there are many factors that affect the performance and life of the finished button battery products, especially the production processes such as liquid filling and packaging, which have many difficulties and low yield rates.

[0003] For example, a Chinese patent discloses a button battery and a method for manufacturing the same, application number 201911397125.1, which includes an upper shell and a lower shell formed by covering each other, and a winding body is provided between the lower shell and the upper shell, and the winding body includes a positive electrode sheet, a negative electrode sheet and an separator located between the positive electrode sheet and the negative electrode sheet for isolating the positive and negative electrode sheets, and the winding body has a positive electrode tab and a negative electrode tab extending above and below the winding body respectively; the positive electrode tab is connected to the positive electrode sheet, and the negative electrode tab is connected to the negative electrode sheet, and at least one of the positive electrode tab and the negative electrode tab is electrically connected to the inner surface of the upper shell or the lower shell opposite to the upper and lower end surfaces of the winding body through a sticky conductive layer. Its disadvantages are: (1) the patent uses a sticky conductive layer to achieve the bonding and conductive function between the tabs and the inner surface of the battery shell, and insulating plates are attached to the upper and lower parts of the winding body to block the conduction between the winding body and the inner surface of the shell. The insulating plates still need to occupy the internal space of the battery shell, reducing the space utilization rate; (2) in order to make the winding body exert a certain pressure on the sticky conductive layer and the tabs during the pressing process, the height of the winding body, the sticky conductive layer, the tabs and the insulating plates is slightly larger than the distance between the two inner surfaces of the shell. The applied pressure will cause certain damage to the winding body, and when injecting liquid, the electrode group as a whole is higher than the battery shell, the injection space is limited, and the injection is relatively difficult; (3) the patent provides an insulating sleeve on the outer peripheral wall of the upper shell, the lower part of the insulating sleeve is bent and covered to the lower part of the inner peripheral wall of the upper shell, and the inner peripheral wall of the lower shell is pressed on the outer periphery of the insulating sleeve to achieve electrical insulation and sealing of the upper and lower shells. The use of the insulating sleeve expands the external dimensions of the battery, and a certain deformation is required to achieve the sealing function. Summary of the Invention

[0004] The object of the present invention is to overcome the deficiencies of the above-mentioned technologies and to provide a button battery and a method for manufacturing the same.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: a button battery and a manufacturing method thereof, characterized in that: a button battery comprises a wound electrode group, a combined shell and a cover plate, the wound electrode group is inside the combined shell, and the combined shell is connected to the cover plate and sealed after folding; the wound electrode group comprises a positive electrode sheet, a negative electrode sheet and a separator; wherein the separator is separated between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet, the separator and the negative electrode sheet are wound to form the wound electrode group, and the positive electrode sheet and the negative electrode sheet are respectively welded with a positive electrode ear and a negative electrode ear, characterized in that: the combined shell It includes a shell, a through-hole tube, and an integrated circuit device; wherein, the shell and the through-hole tube are an integral part, and the through-hole tube is coaxial with the shell, and the ends of the integrated circuit device are respectively welded with a positive terminal, a negative terminal and a protection plate; the integrated circuit device passes through the through-hole tube, and the positive and negative terminals at the ends extend into the interior of the battery and are connected to the positive and negative ears of the wound electrode group, and the protection plate extends to the outside of the battery, and the integrated circuit device is connected and sealed with the through-hole tube by sealant; the wound electrode group is inside the combined shell, and the through-hole tube is inserted into the center hole of the wound electrode group.

[0006] Preferably, the inner wall of the combined shell is coated with a coating that can achieve insulation function.

[0007] Preferably, the opening of the combined shell is higher than the end surface of the wound pole group.

[0008] Preferably, the cover plate is connected to and sealed with the folded combined shell.

[0009] A method for manufacturing a button battery, characterized in that it comprises the following steps:

[0010] a) Pole group winding: At least one positive electrode and one negative electrode, as well as a separator separating the positive and negative electrodes, are wound into a pole group using a circular winding needle in a clockwise / counterclockwise direction, with the positive and negative tabs of the pole group placed at the two ends of the pole group diameter respectively;

[0011] b) Inserting the pole group into the shell: Insert the wound pole group into the assembled shell coaxially, and pass the through-hole round tube through the center hole of the wound pole group;

[0012] c) Tab welding: bend the positive and negative tabs of the wound electrode group and the positive and negative terminals of the integrated circuit device towards each other, and then weld them together;

[0013] d) Injection: injecting electrolyte into the battery;

[0014] e) Folding: Fold the mouth of the combined shell;

[0015] f) Encapsulation: Place the cover on top of the assembled housing and then weld it to seal it;

[0016] g) Formation: Activate the battery by charging and discharging.

[0017] Preferably, in step d), the electrolyte is injected in one of the following ways: the first way is to place an injection cup at the mouth of the combined shell, and inject the electrolyte into the injection cup; the second way is to drip the electrolyte directly into the battery; the third way is to inject the electrolyte into the combined shell by immersing the electrode group into the shell;

[0018] The beneficial effects of the present invention are: 1) the inner wall of the combined shell realizes the insulation function, which can reduce the use of insulating gaskets and further improve the utilization rate of the internal space of the battery; 2) the wound electrode group is inserted into the combined shell, and the mouth of the combined shell is higher than the end face of the wound electrode group, which can more advantageously realize liquid injection; 3) by folding the edges of the combined shell and then welding the cover to seal it, the sealing method is simple and reliable, and the processing and manufacturing process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Figure 2 It is a structural schematic diagram of the combined housing of the present invention;

[0021] Figure 3 This is another preferred structure of the present invention. DETAILED DESCRIPTION

[0022] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings and preferred embodiments. Figure 1 、 Figure 2As shown, a button battery includes a wound electrode group 1, a combined shell 2 and a cover plate 3, wherein the wound electrode group 1 includes a positive electrode sheet 11, a negative electrode sheet 12 and a separator 13; wherein the separator 13 is separated between the positive electrode sheet 11 and the negative electrode sheet 12, the positive electrode sheet 11, the separator 13 and the negative electrode sheet 12 are wound to form the wound electrode group 1, and the positive electrode sheet 11 and the negative electrode sheet 12 are respectively welded with a positive electrode ear 14 and a negative electrode ear 15; the combined shell 2 includes a shell 21, a through-hole circular tube 22, and an integrated circuit device 23; wherein the shell 21 and the through-hole circular tube 22 are integral parts, and the through-hole circular tube 22 is coaxial with the shell 21 The ends of the integrated circuit device 23 are welded to a positive terminal 231, a negative terminal 232, and a protective plate 233. The integrated circuit device 23 passes through the through-hole circular tube 22, with the positive and negative terminals 231 and 232 at the ends extending into the battery interior, and the protective plate 233 extending outward from the battery exterior. The integrated circuit device 23 is connected and sealed to the through-hole circular tube 22 with sealant. The wound electrode assembly 1 is located within the combined housing 2, with the through-hole circular tube 22 inserted into the center hole of the wound electrode assembly 1. The positive and negative terminals 231 and 232 at the ends of the integrated circuit device 23 are connected to the positive and negative tabs 14 and 15 of the wound electrode assembly. The inner wall of the combined housing employed in the present invention provides insulation, reducing the need for insulating washers and further improving internal battery space utilization.

[0023] Preferably, the inner wall of the combined shell 2 is coated with a coating that can achieve an insulating function to improve the safety of the battery and further improve the utilization rate of the internal space of the battery.

[0024] Preferably, the opening of the combined housing 2 is higher than the end face of the wound electrode assembly 1, which facilitates liquid injection. The cover plate 3 is connected and sealed to the folded combined housing 2. This cover plate can compress the electrode assembly, completely filling the internal space of the battery, ensuring that there is no relative movement between the electrode assembly and the battery case during use, thereby improving safety. The combined housing opening employed in the present invention is higher than the end face of the wound electrode assembly, allowing for liquid injection methods such as immersion, cup filling, and dripping, achieving more advantageous liquid injection.

[0025] The present invention further provides a method for manufacturing a button battery, which is applied to manufacture the button battery provided by the above technical solution, and comprises:

[0026] a) Pole group winding: At least one positive electrode and one negative electrode, as well as a separator separating the positive and negative electrodes, are wound into a pole group using a circular winding needle in a clockwise / counterclockwise direction, with the positive and negative tabs of the pole group placed at the two ends of the pole group diameter respectively;

[0027] b) Inserting the pole group into the shell: Insert the wound pole group into the assembled shell coaxially, and pass the through-hole round tube through the center hole of the wound pole group;

[0028] c) Tab welding: bend the positive and negative tabs of the wound electrode group and the positive and negative terminals of the integrated circuit device towards each other, and then weld them together;

[0029] d) Injection: The electrolyte is injected into the battery. One of the following methods can be used: the first method is to place an injection cup at the mouth of the assembled shell and inject the electrolyte into the injection cup; the second method is to drip the electrolyte directly into the battery; the third method is to inject the electrolyte into the assembled shell by immersing the electrode group into the shell;

[0030] e) Folding: Fold the mouth of the combined shell;

[0031] f) Encapsulation: Place the cover on top of the assembled housing and then weld it to seal it;

[0032] g) Formation: Activate the battery by charging and discharging.

[0033] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A button battery, comprising a wound electrode assembly, a combined housing, and a cover plate, wherein the wound electrode assembly is inside the combined housing, and the combined housing is folded and connected to the cover plate and sealed; the wound electrode assembly comprises a positive electrode sheet, a negative electrode sheet, and a separator; wherein: The diaphragm is separated between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet, the diaphragm and the negative electrode sheet are wound to form the wound electrode group, and the positive electrode sheet and the negative electrode sheet are respectively welded with a positive electrode ear and a negative electrode ear, and the characteristic is that: the combined shell comprises a shell, a through-hole round tube, and an integrated circuit device; wherein, the shell and the through-hole round tube are an integral part, and the through-hole round tube and the shell are coaxial, and the ends of the integrated circuit device are respectively welded with a positive terminal, a negative terminal and a protection plate; the integrated circuit device passes through the through-hole round tube, and the positive and negative terminals at the ends extend into the interior of the battery and are connected to the positive and negative ears of the wound electrode group, the protection plate extends to the outside of the battery, and the integrated circuit device is connected and sealed to the through-hole round tube by a sealant; the wound electrode group is inside the combined shell, and the through-hole round tube is inserted into the center hole of the wound electrode group; The inner wall of the combined shell is coated with a coating that can achieve insulation function; The opening of the combined shell is higher than the end surface of the wound pole group.

2. The button battery according to claim 1, wherein: The cover plate is connected to the folded combined shell and sealed.

3. A method for manufacturing a button battery according to claim 1 or 2, characterized in that: It includes the following steps: a) Pole group winding: At least one positive electrode and one negative electrode, as well as a separator separating the positive and negative electrodes, are wound into a pole group using a circular winding needle in a clockwise / counterclockwise direction, with the positive and negative tabs of the pole group placed at the two ends of the pole group diameter respectively; b) Inserting the pole group into the shell: Insert the wound pole group into the assembled shell coaxially, and pass the through-hole round tube through the center hole of the wound pole group; c) Tab welding: bend the positive and negative tabs of the wound electrode group and the positive and negative terminals of the integrated circuit device towards each other, and then weld them together; d) Injection: injecting electrolyte into the battery; e) Folding: Fold the mouth of the combined shell; f) Encapsulation: Place the cover on top of the assembled housing and then weld it to seal it; g) Formation: Activate the battery by charging and discharging.

4. The method for manufacturing a button battery according to claim 3, wherein: In step d), the electrolyte is injected in one of the following ways: the first way is to place an injection cup at the mouth of the combined shell and inject the electrolyte into the injection cup; the second way is to drip the electrolyte directly into the battery; the third way is to inject the electrolyte into the combined shell and immerse the electrode group into the shell.

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