阅读说明：本技术 钢壳扣式电池及其制备方法 (Steel shell button cell and preparation method thereof ) 是由 李路强 沈立强 朱剑峰 刘志伟 曾贤华 于 2021-09-28 设计创作，主要内容包括：本申请提供一种钢壳扣式电池及其制备方法。上述的钢壳扣式电池的制备方法包括以下步骤：将顶盖组件、底壳及密封盖进行冲制成型操作,其中底壳冲制有容纳腔、放置口和注液口,注液口与放置口分别开设于底壳的两侧；将电芯组件中的正极耳与顶盖组件进行第一次焊接操作；将电芯组件中的负极耳与底壳进行第二次焊接操作；将电芯组件放入底壳中,并进行合盖操作；将顶盖组件与底壳的边缘进行第一次激光焊接操作,得到待注液电池；在真空条件下对待注液电池进行注电解液操作；将密封盖盖设于注液口,并在真空条件下对密封盖与底壳进行第二次激光焊接操作,得到钢壳扣式电池。上述钢壳扣式电池的制备方法能够有效防止漏液和提高焊接效果。(The application provides a steel shell button cell and a preparation method thereof. The preparation method of the steel shell button cell comprises the following steps: performing punching molding operation on the top cover assembly, the bottom shell and the sealing cover, wherein the bottom shell is punched with an accommodating cavity, a placing opening and a liquid injection opening, and the liquid injection opening and the placing opening are respectively arranged on two sides of the bottom shell; carrying out first welding operation on a positive lug and a top cover assembly in the electric core assembly; carrying out secondary welding operation on the negative electrode lug and the bottom shell in the electric core assembly; placing the electric core component into the bottom shell, and performing cover closing operation; performing first laser welding operation on the edges of the top cover assembly and the bottom shell to obtain a battery to be injected; injecting electrolyte into the battery to be injected under the vacuum condition; and covering the sealing cover on the liquid injection port, and performing second laser welding operation on the sealing cover and the bottom shell under a vacuum condition to obtain the steel shell button cell. The preparation method of the steel shell button cell can effectively prevent liquid leakage and improve welding effect.)

1. The preparation method of the steel-shell button cell is characterized by comprising the following steps:

performing punching molding operation on the top cover assembly, the bottom shell and the sealing cover, wherein the bottom shell is provided with an accommodating cavity, a placing opening and a liquid injection opening, the liquid injection opening is communicated with the accommodating cavity, and the liquid injection opening and the placing opening are respectively formed on two sides of the bottom shell;

carrying out first welding operation on a positive electrode tab in the electrode core assembly and the top cover assembly;

carrying out secondary welding operation on a negative electrode tab in the battery pack and the bottom shell;

placing the electric core assembly into the bottom shell, and performing cover closing operation;

performing first laser welding operation on the top cover assembly and the edge of the bottom shell to obtain a battery to be injected;

injecting electrolyte into the battery to be injected under a vacuum condition;

and covering the sealing cover on the liquid injection port, and performing second laser welding operation on the sealing cover and the bottom shell under a vacuum condition to obtain the steel shell button cell.

2. The method for manufacturing a steel-shell button cell according to claim 1, wherein the method for manufacturing a steel-shell button cell further comprises the following steps after the step of performing the second welding operation on the negative electrode tab and the bottom shell in the electrode assembly and before the step of placing the electrode assembly in the bottom shell and performing the covering operation:

and carrying out laser engraving two-dimensional code operation on the outer part of the bottom shell.

3. The method for preparing a steel-shell button cell according to claim 1, wherein after the step of performing a first laser welding operation on the top cover assembly and the edge of the bottom shell to obtain a battery to be charged, and before the step of performing an electrolyte injection operation on the battery to be charged under vacuum conditions, the method for preparing a steel-shell button cell further comprises the following steps:

and carrying out primary sealing detection operation on the battery to be injected.

4. The method for preparing a steel-shell button cell according to claim 1, wherein after the step of performing a first laser welding operation on the top cover assembly and the edge of the bottom shell to obtain a battery to be charged, and before the step of performing an electrolyte injection operation on the battery to be charged under vacuum conditions, the method for preparing a steel-shell button cell further comprises the following steps:

and carrying out battery core baking operation on the battery to be injected.

5. The method for preparing a steel-shell button cell according to claim 1, wherein after the step of performing a first laser welding operation on the top cover assembly and the edge of the bottom shell to obtain a battery to be charged, and before the step of performing an electrolyte injection operation on the battery to be charged under vacuum conditions, the method for preparing a steel-shell button cell further comprises the following steps:

and carrying out first weighing operation on the battery to be injected.

6. The method for manufacturing a steel-shell button cell according to claim 5, wherein after the step of injecting the electrolyte into the cell under vacuum, and before the step of covering the sealing cover on the injection port and performing the second laser welding operation on the sealing cover and the bottom shell under vacuum to obtain the steel-shell button cell, the method further comprises the following steps:

and carrying out secondary weighing operation on the battery after liquid injection.

7. The method for preparing the steel-shell button cell according to claim 1, wherein the electrolyte injection operation specifically comprises the following steps:

carrying out primary liquid injection operation on the battery to be injected to obtain a pre-injected battery;

carrying out vacuum standing operation on the pre-injection battery;

and carrying out secondary liquid injection operation on the pre-injection battery after the vacuum standing operation is finished.

8. The method for preparing the steel-shell button cell according to claim 7, wherein the vacuum standing operation is performed for 1-2 hours.

9. The method for manufacturing a steel-shelled button cell according to claim 1, wherein after the step of covering a sealing cover on a liquid injection port and performing a second laser welding operation on the sealing cover and the bottom shell under vacuum conditions to obtain the steel-shelled button cell, the method for manufacturing a steel-shelled button cell further comprises the following steps:

and carrying out secondary sealing detection operation on the steel shell button cell.

10. A steel-shell button cell, which is characterized in that the steel-shell button cell is prepared by the preparation method of the steel-shell button cell according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of batteries, in particular to a steel shell button cell and a preparation method thereof.

Background

With the development of portable electronic products and smart wearable electronic products, batteries are required to be more miniaturized. While maintaining a long service life, the battery is required to have the highest possible volumetric energy and mass energy, so that the demand of the steel-shell button battery is increased.

The traditional steel shell button type battery generally adopts the following two packaging modes, namely, a positive shell and a negative shell of the steel shell button type battery are mutually buckled through an inner diameter difference and are fixedly connected through a clamping groove at the joint of the upper shell and the lower shell; and secondly, the upper edge of the anode shell is turned over, so that the anode cover is buckled by the upper edge of the anode shell, and the cathode cover is fixed. The traditional steel-shell button cell packaging mode and the traditional cover closing mode are easy to cause liquid leakage. In addition, after the top and bottom steel shells are soaked by the electrolyte, fog frost surfaces can be formed on the surfaces, and the fog frost layers can be heated and evaporated to generate bubbles during laser high-temperature welding, so that a welded joint has poor rosin joint and pores; electrolyte residues exist on the surface of the steel shell, and mixed gas is evaporated and released during laser high-temperature welding, so that the color of the surface of a welding line is poor.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a steel shell button cell which can effectively prevent liquid leakage, improve the welding effect and has better sealing property and a preparation method thereof.

The purpose of the invention is realized by the following technical scheme:

a preparation method of a steel-shell button cell comprises the following steps:

performing punching molding operation on the top cover assembly, the bottom shell and the sealing cover, wherein the bottom shell is provided with an accommodating cavity, a placing opening and a liquid injection opening, the liquid injection opening is communicated with the accommodating cavity, and the liquid injection opening and the placing opening are respectively formed on two sides of the bottom shell;

carrying out first welding operation on a positive electrode tab in the electrode core assembly and the top cover assembly;

carrying out secondary welding operation on a negative electrode tab in the battery pack and the bottom shell;

placing the electric core assembly into the bottom shell, and performing cover closing operation;

performing first laser welding operation on the top cover assembly and the edge of the bottom shell to obtain a battery to be injected;

injecting electrolyte into the battery to be injected under a vacuum condition;

and covering the sealing cover on the liquid injection port, and performing second laser welding operation on the sealing cover and the bottom shell under a vacuum condition to obtain the steel shell button cell.

In one embodiment, after the step of performing the second welding operation on the negative electrode tab and the bottom case in the battery assembly and before the step of placing the battery assembly in the bottom case and performing the cover closing operation, the method for manufacturing the steel-case button cell further comprises the following steps:

and carrying out laser engraving two-dimensional code operation on the outer part of the bottom shell.

In one embodiment, after the step of performing the first laser welding operation on the top cover assembly and the edge of the bottom case to obtain the battery to be injected, and before the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, the method for preparing the steel case button cell further comprises the following steps:

and carrying out primary sealing detection operation on the battery to be injected.

In one embodiment, after the step of performing the first laser welding operation on the top cover assembly and the edge of the bottom case to obtain the battery to be injected, and before the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, the method for preparing the steel case button cell further comprises the following steps:

and carrying out battery core baking operation on the battery to be injected.

In one embodiment, after the step of performing the first laser welding operation on the top cover assembly and the edge of the bottom case to obtain the battery to be injected, and before the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, the method for preparing the steel case button cell further comprises the following steps:

and carrying out first weighing operation on the battery to be injected.

In one embodiment, after the step of performing the electrolyte injection operation on the battery to be injected under vacuum conditions, and before the step of covering the sealing cover on the injection port and performing the second laser welding operation on the sealing cover and the bottom case under vacuum conditions to obtain the steel-case button cell, the method for manufacturing the steel-case button cell further comprises the following steps:

and carrying out secondary weighing operation on the battery after liquid injection.

In one embodiment, the electrolyte injection operation specifically includes the following steps:

carrying out primary liquid injection operation on the battery to be injected to obtain a pre-injected battery;

carrying out vacuum standing operation on the pre-injection battery;

and carrying out secondary liquid injection operation on the pre-injection battery after the vacuum standing operation is finished.

In one embodiment, the vacuum standing operation is performed for 1 hour to 2 hours.

In one embodiment, after the step of covering the sealing cover on the liquid injection port and performing the second laser welding operation on the sealing cover and the bottom case under vacuum conditions to obtain the steel-case button cell, the method for manufacturing the steel-case button cell further comprises the following steps:

and carrying out secondary sealing detection operation on the steel shell button cell.

A steel-shell button cell is prepared by the preparation method of the steel-shell button cell in any embodiment.

Compared with the prior art, the invention has at least the following advantages:

1. according to the preparation method of the steel-shell button cell, the top cover assembly, the bottom shell and the sealing cover are subjected to punching forming operation, wherein the bottom shell is provided with the accommodating cavity, the placing opening and the liquid injection opening, the accommodating cavity is used for placing the electric core assembly, the liquid injection opening is punched and formed in the bottom shell instead of the top cover assembly, and the liquid injection opening and the placing opening are formed in two sides of the bottom shell respectively, so that the electric core assembly placing operation and the liquid injection operation are conveniently performed in two different parts of the bottom shell respectively, the situation that partial electrolyte is remained in the placing opening after the electrolyte is injected into the electric core is prevented, and the stability of the cover combining welding operation of the steel-shell button cell is improved.

2. According to the preparation method of the steel-shell button cell, the positive pole tab in the cell assembly is welded to the top cover assembly, the negative pole tab is welded to the bottom shell, the cell assembly is placed into the bottom shell, the top cover assembly and the bottom shell are closed, and then the top cover assembly and the edge of the bottom shell are subjected to first laser welding operation, so that the top cover assembly and the bottom shell are sealed. Because the laser welding operation between top cap subassembly and the drain pan is accomplished before annotating the liquid for top cap subassembly and drain pan can eliminate the influence of remaining electrolyte effectively, thereby improve steel-shell button cell's laser welding stability effectively, improve steel-shell button cell's leakproofness simultaneously.

3. According to the preparation method of the steel-shell button cell, after the cell to be injected is obtained, the cell to be injected is subjected to electrolyte injection operation under the vacuum condition, then the sealing cover is covered on the electrolyte injection port, and the sealing cover and the bottom shell are subjected to second laser welding operation under the vacuum condition. The electrolyte injection operation and the sealing welding operation are all completed under the vacuum condition, so that the stability of the electrolyte injection operation is effectively guaranteed, the cleanness and tidiness of the periphery of the liquid injection port are improved, meanwhile, the interference of external conditions on the second laser welding operation is prevented, and the sealing performance of the steel shell button cell is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a flow chart of a method for manufacturing a steel case button cell in one embodiment;

FIG. 2 is a flow chart of the operation of injecting electrolyte in the preparation method of the steel-can button cell shown in FIG. 1;

fig. 3 is a schematic diagram of an explosion structure of the steel-case button cell prepared by the method for preparing the steel-case button cell shown in fig. 1;

fig. 4 is a schematic structural view of the assembled steel-shell button cell shown in fig. 3;

fig. 5 is a schematic cross-sectional structure view of the steel-can button cell shown in fig. 3;

fig. 6 is a schematic structural view of an automatic backflow structure in the steel-shell button cell shown in fig. 3;

fig. 7 is a schematic cross-sectional view of an automatic reflow structure in the steel-can button cell shown in fig. 3.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The application provides a preparation method of a steel-shell button cell. The preparation method of the steel shell button cell comprises the following steps: performing punching molding operation on the top cover assembly, the bottom shell and the sealing cover, wherein the bottom shell is provided with an accommodating cavity, a placing opening and a liquid injection opening, the liquid injection opening is communicated with the accommodating cavity, and the liquid injection opening and the placing opening are respectively formed on two sides of the bottom shell; carrying out first welding operation on a positive electrode tab in the electrode core assembly and the top cover assembly; carrying out secondary welding operation on a negative electrode tab in the battery pack and the bottom shell; placing the electric core assembly into the bottom shell, and performing cover closing operation; performing first laser welding operation on the top cover assembly and the edge of the bottom shell to obtain a battery to be injected; injecting electrolyte into the battery to be injected under a vacuum condition; and covering the sealing cover on the liquid injection port, and performing second laser welding operation on the sealing cover and the bottom shell under a vacuum condition to obtain the steel shell button cell.

In the preparation method of the steel-shell button cell, the top cover assembly, the bottom shell and the sealing cover are punched and molded, wherein the bottom shell is formed with a containing cavity, a containing opening and a liquid injecting opening, the containing cavity is used for containing the cell assembly, the liquid injecting opening is punched and molded on the bottom shell but not the top cover assembly, and the liquid injecting opening are formed on two sides of the bottom shell respectively, so that the cell assembly is placed and operated conveniently, the liquid injecting operation is performed on two different parts of the bottom shell respectively, the situation that partial electrolyte is remained on the containing opening after the electrolyte is injected into the cell is prevented, and the stability of the cover closing welding operation of the steel-shell button cell is improved. Further, weld the anodal utmost point ear in the battery cell subassembly in top cap subassembly and weld negative pole utmost point ear in the drain pan to after putting into the drain pan with the battery cell subassembly, close the lid operation with top cap subassembly and drain pan earlier, then carry out the laser welding operation for the first time with the edge of top cap subassembly and drain pan, thereby realize the sealed of top cap subassembly and drain pan. Because the laser welding operation between top cap subassembly and the drain pan is accomplished before annotating the liquid for top cap subassembly and drain pan can eliminate the influence of remaining electrolyte effectively, thereby improve steel-shell button cell's laser welding stability effectively, improve steel-shell button cell's leakproofness simultaneously. Further, after the battery to be injected is obtained, the battery to be injected is subjected to an electrolyte injection operation under vacuum conditions, then the sealing cover is covered on the electrolyte injection port, and the sealing cover and the bottom case are subjected to a second laser welding operation under vacuum conditions. The electrolyte injection operation and the sealing welding operation are all completed under the vacuum condition, so that the stability of the electrolyte injection operation is effectively guaranteed, the cleanness and tidiness of the periphery of the liquid injection port are improved, meanwhile, the interference of external conditions on the second laser welding operation is prevented, and the sealing performance of the steel shell button cell is improved.

In order to better understand the method for manufacturing the steel-casing button cell of the present invention, the method for manufacturing the steel-casing button cell of the present invention is further explained below, and as shown in fig. 1, one embodiment of the method for manufacturing the steel-casing button cell is used to manufacture the steel-casing button cell. Further, the preparation method comprises part or all of the following steps:

s100, the top cover assembly, the bottom shell and the sealing cover are subjected to punching forming operation, wherein the bottom shell is provided with a containing cavity, a placing opening and a liquid injection opening, the liquid injection opening is communicated with the containing cavity, and the liquid injection opening and the placing opening are formed in two sides of the bottom shell respectively.

In this embodiment, the top cover assembly includes an upper shell and a shell cap, and the upper shell, the shell cap, the bottom shell and the sealing cover are formed by punching so that the upper shell, the shell cap, the bottom shell and the sealing cover are combined into the outer shell of the steel-shell button cell. Further, the drain pan is formed with through stamping process and holds the chamber, places the mouth and annotates the liquid mouth, holds the chamber and is used for placing electric core subassembly, and electric core subassembly is from placing the mouth entering and holding the chamber, annotates the injection that the liquid mouth is used for electrolyte. It should be noted that, in the existing steel-shell button cell, the placing port for placing the battery core and the liquid injection port are the same opening, after the battery core is placed into the shell from the placing port, electrolyte is injected into the battery core from the placing port, and after the liquid injection is completed, the top cover is arranged on the placing port, and the sealing welding operation is performed. However, when the operation of closing the lid, because the top cap can lead to the fact an extrusion force to electric core, the electrolyte that makes in the electric core appears climbing the limit or the condition that spills over after the pressurized, has to appear partial electrolyte and remain in the condition of placing the mouth after the electrolyte pours into electric core into promptly to form the fog frost face on the box hat surface, the fog frost layer can be heated the evaporation and produce the bubble when laser high temperature fusion, leads to rosin joint and gas pocket to appear badly. And in this embodiment, annotate the liquid mouth shaping in the drain pan rather than top cap subassembly, and annotate the liquid mouth and place the mouth and set up respectively in the both sides of drain pan to be convenient for go on two different positions of drain pan with the operation of placing of electricity core subassembly with annotating the liquid operation respectively, avoided traditional box-hat button cell to appear partial electrolyte after electrolyte pours into electric core and remain in the condition of placing the mouth, thereby improve box-hat button cell's the stability of closing lid welding operation.

S200, carrying out first welding operation on the positive pole lug and the top cover assembly in the electric core assembly.

In this embodiment, the electric core subassembly includes core, anodal utmost point ear and negative pole utmost point ear, and the core is connected with anodal utmost point ear and negative pole utmost point ear respectively, and is equipped with anodal connecting portion in the top cap subassembly. Before the electric core assembly is placed into the accommodating cavity, the positive pole lug in the electric core assembly and the top cover assembly are subjected to first welding operation, so that the core body is conducted with the top cover assembly, and the positive pole of the steel shell button cell is formed.

S300, carrying out secondary welding operation on the negative pole lug and the bottom shell in the electric core assembly.

In this embodiment, the electric core assembly includes core, anodal utmost point ear and negative pole utmost point ear, and the core is connected with anodal utmost point ear and negative pole utmost point ear respectively, and is equipped with negative pole connecting portion in the drain pan. Before the electric core assembly is put into the containing cavity, the negative pole tab in the electric core assembly and the bottom shell are subjected to secondary welding operation, so that the core body is conducted with the bottom shell, and the negative pole of the steel shell button cell is formed.

S400, placing the electric core assembly into the bottom shell, and performing cover closing operation.

In this embodiment, the cover closing operation is to cover the top cover assembly over the placing opening of the bottom case, so as to perform a further laser welding operation on the top cover assembly and the bottom case. When the cell subassembly was put into the drain pan, with anodal utmost point ear and negative pole utmost point ear operation of buckling to in accomodate the cell subassembly better in holding the intracavity, thereby improve the planarization behind the top cap subassembly close the lid, prevent effectively that the top cap subassembly from closing the condition of taking place the dislocation behind the lid, and then be favorable to the further laser welding operation of top cap subassembly and drain pan. Further, a first groove is formed in the bottom shell, a second groove is formed in the top cover assembly, when the cell assembly is placed in the accommodating cavity, the positive pole lug and the negative pole lug are both in a bending shape, the bending positive pole lug is placed in the second groove, and the bending negative pole lug is placed in the first groove, so that the smoothness between the cell assembly and the bottom shell and the top cover assembly is improved, and the structural stability of the steel shell button cell is improved.

And S500, carrying out first laser welding operation on the edges of the top cover assembly and the bottom shell to obtain the battery to be injected.

In this embodiment, after the top cover assembly and the bottom case are closed, the top cover assembly and the edge of the bottom case are subjected to a first laser welding operation, including laser welding between the top cover assembly and the bottom case and laser welding between the upper case and the case cap, so as to seal the top cover assembly and the bottom case. And accomplish before leading the liquid process of annotating of laser welding operation between epitheca and the shell cap in this embodiment for top cap subassembly and drain pan can eliminate the influence of remaining electrolyte effectively, prevent that electrolyte from being heated and producing the bubble, thereby improve steel-shelled button cell's laser welding stability effectively, improve steel-shelled button cell's leakproofness simultaneously.

S600, injecting electrolyte into the battery to be injected under the vacuum condition.

In this embodiment, the battery to be injected with the electrolyte is subjected to an electrolyte injection operation under a vacuum condition, specifically, the electrolyte is injected into the accommodating cavity from the electrolyte injection port, so that the core body is soaked in the electrolyte. Furthermore, the electrolyte injection port is punched and formed in the bottom shell instead of the top cover assembly, and the top cover assembly and the bottom shell are welded and sealed, so that the electrolyte leakage can be avoided during the electrolyte injection operation. In addition, the operation of injecting the electrolyte is completed under the vacuum condition, so that the stability of the operation of injecting the electrolyte can be effectively ensured, and the tidiness of the periphery of the injection port is improved.

And S700, covering the sealing cover on the liquid injection port, and performing second laser welding operation on the sealing cover and the bottom shell under a vacuum condition to obtain the steel-shell button cell.

In this embodiment, after the electrolyte is injected into the battery to be injected under vacuum condition, the sealing cover is covered on the injection port, and the sealing cover and the bottom case are subjected to the second laser welding operation under vacuum condition, so that the sealing performance and stability of the steel-case button battery are improved. In addition, above-mentioned notes electrolyte operation and seal welding operation are all accomplished under vacuum condition to guarantee effectively and annotate the stability of electrolyte operation, improve and annotate the peripheral clean and tidy nature of liquid mouth, prevent simultaneously that external condition from to the interference of laser welding operation of second time, and then improve steel-shelled button cell's leakproofness, obtain steel-shelled button cell. It can be understood that the subsequent processes of the steel-shell button cell further include capacity grading, formation, standing and the like.

In one embodiment, after the step of performing the second welding operation on the negative electrode tab and the bottom case in the cell assembly and before the step of placing the cell assembly into the bottom case and performing the cover closing operation, the method for manufacturing the steel-case button cell further comprises the following steps: and carrying out laser engraving two-dimensional code operation on the outer part of the bottom shell. It can be understood that the steel-shell button cell includes more complicated links in the preparation process, wherein a plurality of links need to test and check related data of the steel-shell button cell, and because the data is more and more complicated, if the data recording is not comprehensive and accurate enough, the preparation process of the steel-shell button cell is easy to generate errors. In addition, because the volume of the steel-shell button cell is smaller, the related performance indexes of the steel-shell button cell are difficult to print on the surface of the shell. In order to improve the fine management of the production method of the steel-shell button cell, in this embodiment, after the step of performing the second welding operation on the negative electrode tab and the bottom case in the cell assembly, and before the step of placing the cell assembly into the bottom case and performing the lid-closing operation, the method for manufacturing the steel-shell button cell further includes the following steps: the laser engraving two-dimensional code operation is carried out on the outer portion of the bottom shell, the two-dimensional code can play a role in identifying and distinguishing the steel shell button cell, the two-dimensional code has high-density codes, the information capacity is large, the coding range is wide, the fault-tolerant capability is strong, the error correction function and the decoding reliability are high, the steel shell button cell can be identified and recorded through the two-dimensional code, a refined production mode of code scanning management can be adopted in the steel shell button cell manufacturing process, the test of each link in the manufacturing process and the automatic storage to an MES system after code scanning of inspection data are realized, the reliability of each performance index output of each finished steel shell button cell is improved, and the production efficiency and the yield are improved simultaneously. In addition, the two-dimensional code is engraved outside the bottom shell in a laser engraving mode, so that the two-dimensional code can be more easily identified on one hand; on the other hand, the two-dimension code is not easy to scratch or rub off in the preparation process, so that the stability of the two-dimension code is improved.

In one embodiment, after the step of performing the first laser welding operation on the top cover assembly and the edge of the bottom case to obtain the battery to be injected, and before the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, the method for preparing the steel case button cell further comprises the following steps: and carrying out primary sealing detection operation on the battery to be injected. It can be understood that after the first laser welding operation is performed on the edges of the top cover assembly and the bottom shell, some gaps which are not completely welded may occur, but are not easily identified by naked eyes, that is, the battery to be injected has a problem of poor sealing performance, and if the gaps are not processed in time, leakage is easily caused in the subsequent injection process. In order to improve the sealing performance of the steel-shell button cell, in this embodiment, after the step of performing the first laser welding operation on the edge of the top cover assembly and the edge of the bottom case to obtain the battery to be injected, and before the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, the method for manufacturing the steel-shell button cell further includes the following steps: under the vacuum condition, the battery to be injected is subjected to primary sealing detection operation, and through the vacuum sealing detection operation, whether the situation that the sealing performance is poor exists at the welding part of the top cover assembly and the edge of the bottom shell or not can be identified and judged, so that repair welding operation is timely performed, the sealing performance of the steel shell button battery is improved, and the situation that liquid leakage occurs in the steel shell button battery in the subsequent liquid injection process is avoided.

In one embodiment, after the step of performing the first laser welding operation on the top cover assembly and the edge of the bottom case to obtain the battery to be injected, and before the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, the method for preparing the steel case button cell further comprises the following steps: and carrying out battery core baking operation on the battery to be injected. It can be understood that, treat to annotate liquid battery before annotating the electrolyte operation, because electric core subassembly, top cap subassembly and drain pan exist moisture easily in the assembling process, make electrolyte pour into and cause mixed interference after treating to annotate liquid battery to influence steel-shelled button cell's performance. In order to improve the performance stability of the steel-shell button cell, in this embodiment, after the step of performing the first laser welding operation on the edge of the top cover assembly and the bottom case to obtain the battery to be injected, and before the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, the method for manufacturing the steel-shell button cell further includes the following steps: the battery core baking operation is carried out on the battery to be injected, so that the moisture existing in the battery to be injected is fully volatilized, the dryness of the structure of the battery to be injected is improved, the interference reaction caused by the mixing of the moisture and the electrolyte is avoided, and the performance stability of the steel shell button battery is improved.

In one embodiment, after the step of performing the first laser welding operation on the top cover assembly and the edge of the bottom case to obtain the battery to be injected, and before the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, the method for preparing the steel case button cell further comprises the following steps: and carrying out first weighing operation on the battery to be injected. It can be understood that, in the process of manufacturing the steel-shell button cell, the amount of electrolyte injected into each steel-shell button cell is easy to be different due to the error of the manufacturing process. If the difference of the injection amount is too large each time, the consistency between the steel-shell button cells is easy to be poor, the cell capacity difference of the steel-shell button cells can be gradually shown after long-term charge and discharge, and particularly for the steel-shell button cells used in combination, the problems of capacity attenuation and poor safety of the battery pack are easy to be caused. In order to improve the consistency of the steel-shell button cell, in this embodiment, after the step of performing the first laser welding operation on the edge of the top cover assembly and the edge of the bottom case to obtain the battery to be injected, and before the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, the method for manufacturing the steel-shell button cell further includes the following steps: the operation of weighing for the first time is carried out to the battery of treating annotating liquid, obtains the weight of treating annotating the liquid battery, and the weight of steel-shelled button cell before pouring into electrolyte promptly is marked as first weight value to in the steel-shelled button cell weight after pouring into electrolyte contrast, be favorable to more accurately obtaining the weight of pouring into electrolyte.

Further, after the step of performing the operation of injecting the electrolyte into the battery to be injected under the vacuum condition, and before the step of covering the sealing cover on the injection port and performing the second laser welding operation on the sealing cover and the bottom case under the vacuum condition to obtain the steel-case button cell, the method for manufacturing the steel-case button cell further comprises the following steps: and carrying out secondary weighing operation on the battery after liquid injection to obtain the weight of the steel shell button battery after the electrolyte is injected, recording the weight as a second weight value, and subtracting the first weight value from the second weight value to obtain a weight difference value, namely the weight of the injected electrolyte. Through the measurement of the weight of the injected electrolyte, the amount of the electrolyte injected each time can be further controlled, so that the consistency of the steel-shell button cell is effectively improved.

In one embodiment, after the step of injecting the electrolyte into the battery to be injected under vacuum condition, and before the step of covering the sealing cover on the injection port and performing the second laser welding operation on the sealing cover and the bottom case under vacuum condition to obtain the steel-case button cell, the method for manufacturing the steel-case button cell further comprises the following steps: and performing a rotation operation on the battery after the electrolyte is injected. It can be understood that, because the volume of the steel-shell button cell is small, the electrolyte is easily concentrated into one cell after being injected into the cell, and cannot be uniformly infiltrated into the edges and corners inside the steel-shell button cell. In order to improve the uniformity of the electrolyte inside the steel-shell button cell, in this embodiment, after the step of performing the electrolyte injection operation on the battery to be injected under the vacuum condition, and before the step of covering the sealing cover on the electrolyte injection port and performing the second laser welding operation on the sealing cover and the bottom shell under the vacuum condition to obtain the steel-shell button cell, the method for manufacturing the steel-shell button cell further includes the following steps: and rotating the battery injected with the electrolyte, specifically, placing the battery injected with the electrolyte in a rotating mechanism, and rotating the electrolyte in the battery along with the rotating mechanism. The electrolyte can be infiltrated into the edge and the corner of the steel shell button cell by the centrifugal force generated by rotation, so that the uniformity of the electrolyte in the steel shell button cell is improved, and the electrochemical performance of the steel shell button cell is improved. Further, the sealing cover is covered on the liquid injection port, and the sealing cover and the bottom shell are subjected to laser welding operation for the second time under vacuum conditions, and are simultaneously subjected to rotation operation. The electrolyte can be infiltrated into the edge and the corner of the steel shell button cell by the centrifugal force generated by rotation, so that the uniformity of the electrolyte in the steel shell button cell is improved, meanwhile, the welding positions of the sealing cover and the bottom shell are switched by the rotation of the steel shell button cell, the welding accuracy and stability can be effectively improved, and the efficiency of secondary laser welding is improved.

As shown in fig. 2, in one embodiment, the electrolyte injection operation specifically includes the following steps:

s610, carrying out primary liquid injection operation on the battery to be injected with the liquid to obtain the pre-injection battery.

It can be understood that, because the structure of the electric core assembly in the battery to be injected is compact, after the electrolyte is injected, the electrolyte can be completely soaked in the electric core assembly within a certain time. If the electrolyte is injected into the battery to be injected at one time, the problem of uneven bubble or electrolyte infiltration is easy to occur, so that the electrical performance of the steel-shell button battery is influenced. In order to improve the uniformity of the electrolyte after the electrolyte is injected into the battery to be injected, in the embodiment, the battery to be injected is subjected to a first injection operation, so that a part of the electrolyte firstly infiltrates the core body, and meanwhile, air in the battery to be injected is removed, so that the electrolyte is fully and uniformly infiltrated into the battery to be injected, and the problem that bubbles or uneven infiltration of the electrolyte easily occurs in the injection process is effectively solved.

And S620, carrying out vacuum standing operation on the pre-injection battery.

It can be understood that, because the structure of the electric core component in the battery to be injected is compact, after the electrolyte is injected through the first injection operation, a certain time is needed to enable the electrolyte to be completely soaked in the core in the electric core component. In order to further improve the uniformity of the electrolyte injected into the battery to be injected, in this embodiment, the battery to be injected is subjected to a vacuum standing operation, so that the electrolyte is more fully soaked in the edges and corners of the battery to be injected, thereby further improving the uniformity of the electrolyte injected into the battery to be injected.

And S630, performing secondary liquid injection operation on the pre-injection battery after the vacuum standing operation is completed.

It can be understood that after the pre-injection battery is subjected to a vacuum standing operation, the electrolyte injected for the first time is uniformly soaked in the bottom of the steel-shell button cell. In order to further fully and uniformly infiltrate the core body, in the embodiment, the pre-liquid injection battery after the vacuum standing operation is performed is subjected to a second liquid injection operation, so that the electrolyte is stably increased, meanwhile, because the air in the battery to be injected is driven away by the first liquid injection operation, the core body can be fully infiltrated in the electrolyte through the second liquid injection operation, and meanwhile, the problem that bubbles or the electrolyte is unevenly infiltrated in the liquid injection process is effectively solved, and further, the electrochemical performance of the steel shell button battery is effectively improved.

In one embodiment, the vacuum standing operation is performed for 1 hour to 2 hours. It can be understood that the vacuum standing operation can enable the electrolyte to be more fully soaked at the edge and the corner of the battery to be injected, so that the uniformity of the electrolyte after being injected into the battery to be injected is improved. However, if the vacuum standing operation time is short, the injected electrolyte is likely to be unable to sufficiently infiltrate into the edges and corners of the battery to be infused, so that the problem of uneven infiltration of bubbles or electrolyte is likely to occur; if the vacuum standing operation is carried out for a long time, the preparation efficiency of the steel-shell button cell is easily reduced. In order to further improve the uniformity of the electrolyte after being injected into the battery to be injected, in this embodiment, the time of the vacuum standing operation is 1 hour to 2 hours, so that the electrolyte injected by the first injection operation can be fully and uniformly soaked in the edge and the corner of the battery to be injected, thereby further improving the uniformity of the electrolyte after being injected into the battery to be injected, and further improving the electrochemical performance of the steel-shell button battery.

In one embodiment, after the step of covering the sealing cover on the liquid injection port and performing the second laser welding operation on the sealing cover and the bottom case under vacuum conditions to obtain the steel-case button cell, the method for manufacturing the steel-case button cell further comprises the following steps: and carrying out secondary sealing detection operation on the steel shell button cell. It can be understood that after the second laser welding operation is performed on the sealing cover and the bottom shell, some gaps which are not completely welded but are not easily identified by naked eyes may occur, that is, the battery to be filled has the problem of poor sealing performance, and if the sealing cover and the bottom shell are not processed in time, liquid leakage is easily caused. In order to further ensure the sealing performance of the steel-shell button cell, in this embodiment, after the step of covering the sealing cover on the liquid injection port and performing the second laser welding operation on the sealing cover and the bottom shell under the vacuum condition to obtain the steel-shell button cell, the method for manufacturing the steel-shell button cell further includes the following steps: the steel shell button cell is subjected to secondary sealing detection operation, and whether the sealing cover and the bottom shell welding part has the condition of poor sealing performance or not can be identified and judged through the secondary sealing detection operation, so that repair welding operation is timely performed, the sealing performance of the steel shell button cell is improved, and the condition of liquid leakage of the steel shell button cell in the subsequent use process is avoided. Further, the diameter of the sealing cover is 3 mm-4 mm. It can be understood that the diameter of the sealing cover where the liquid injection port of the existing steel-shell button cell is located is 12mm, the length of the sealing welding bead after liquid injection is 38mm, the sealing welding bead is long, which easily prolongs the process time, and the welding heating time of the shell 710 is long, which easily causes the electrolyte to be heated to generate bubbles, thereby affecting the performance of the steel-shell button cell. In order to seal the length of the welding bead after liquid injection, shorten the heating time and reduce bubbles generated by heating the electrolyte, in the embodiment, the diameter of the sealing cover is 3-4 mm, compared with the length of the sealing welding bead after the liquid injection of the existing steel shell button cell, the length of the sealing welding bead after the liquid injection is shortened from 37.8mm to 11mm, and the length of the sealing welding bead is reduced by 26.8 mm; the welding heating time is shortened from 8.5S/PCS to 3.5S/PCS, and the welding time is shortened by 5S, so that the length of a sealing welding bead is effectively reduced, the heating time is shortened, the electrolyte is prevented from being heated to generate bubbles, and the stability of the steel-shell button cell during sealing is further improved.

The application also provides a steel-shell button cell which is prepared by adopting the preparation method of the steel-shell button cell in any embodiment. Further, the preparation method of the steel-shell button cell comprises the following steps: carrying out punching molding operation on the top cover assembly, the bottom shell and the sealing cover, wherein the bottom shell is punched with an accommodating cavity, a placing opening and a liquid injection opening, the liquid injection opening is communicated with the accommodating cavity, and the liquid injection opening and the placing opening are respectively arranged on two sides of the bottom shell; carrying out first welding operation on a positive electrode tab in the electrode core assembly and the top cover assembly; carrying out secondary welding operation on a negative electrode tab in the battery pack and the bottom shell; placing the electric core assembly into the bottom shell, and performing cover closing operation; performing first laser welding operation on the top cover assembly and the edge of the bottom shell to obtain a battery to be injected; injecting electrolyte into the battery to be injected under a vacuum condition; and covering the sealing cover on the liquid injection port, and performing second laser welding operation on the sealing cover and the bottom shell under a vacuum condition to obtain the steel shell button cell.

As shown in fig. 3 and 4, in one embodiment, the steel-shell button cell 10 includes a top cover assembly 100, a cell assembly 200, a bottom shell 300 and a sealing cover 400, wherein a receiving cavity 312 is formed in the bottom shell 300, a placing opening 314 is formed in one side of the bottom shell 300, a liquid injection opening 316 is formed in the other side of the bottom shell 300, the placing opening 314 and the liquid injection opening 316 are both communicated with the receiving cavity 312, the diameter of the liquid injection opening 316 is smaller than that of the placing opening 314, the cell assembly 200 is placed in the receiving cavity 312, the top cover assembly 100 is covered on the placing opening 314, and the sealing cover 400 is covered on the liquid injection opening 316.

In this embodiment, the steel-shell button cell 10 includes a top cover assembly 100, a cell assembly 200, a bottom shell 300 and a sealing cover 400, wherein a containing cavity 312 is formed in the bottom shell 300, a placing opening 314 is opened on one side of the bottom shell 300, a liquid injection opening 316 is opened on the other side of the bottom shell 300, and the placing opening 314 and the liquid injection opening 316 are both communicated with the containing cavity 312. It can be understood that, among the present steel-shell button cell, the mouth of placing for placing electric core and annotate the liquid mouth is same opening, after electric core placed the casing from placing the mouth, carries out the injection of electrolyte from placing the mouth to electric core after that, annotates the liquid and locates the top cap lid after accomplishing again and place the mouth to carry out seal welding operation. However, when the cover is closed, because the top cover can cause an extrusion force to electric core, the electrolyte in the electric core appears climbing the limit or the condition that overflows after the pressurized to form the fog frost face on the box hat surface, the fog frost layer can be heated and evaporated and generate bubbles when the laser high temperature welding, and lead to the welding seam to appear rosin joint and the gas pocket is bad. In addition, when the top cover is closed, the top cover is easily dislocated up and down or left and right, so that the top cover slides into the bottom case 300, and the problem of edge sticking of the electrolyte occurs. And place electric core subassembly 200's opening and annotate liquid mouth 316 non-same mouth in this application, make electric core subassembly 200 place the operation and annotate the liquid operation and can go on in steel-shell button cell 10's two places respectively, place electric core subassembly 200 behind holding chamber 312, need not to annotate the liquid and can weld top cap subassembly 100 in the mouth 314 of placing of drain pan 300, improve steel-shell button cell 10's leakproofness, then keep away from in the drain pan 300 again and place the liquid mouth 316 of annotating of mouth 314 one side and pour into electrolyte into, thereby can effectively prevent the weeping, and avoid electrolyte to remain on the steel-shell surface and to the harmful effects that sealing weld caused, and then improve steel-shell button cell 10's leakproofness. Further, the liquid filling port 316 is opened on the side of the bottom case 300 away from the placement port 314, the sealing lid 400 is covered on the liquid filling port 316 after the liquid filling operation is completed through the liquid filling port 316, and the liquid filling port 316 is also equivalent to the sealing port of the steel-case button cell 10. Because the diameter of the liquid injection port 316 is smaller than that of the placing port 314, the sealing cover 400 is not easily polluted by electrolyte when being closed, so that the sealing cover 400 is easier to weld when being closed, and the welding efficiency is improved; meanwhile, the pressure of the sealing cover 400 on the battery cell is small when the cover is closed, so that the situation that electrolyte in the battery cell overflows from the surface of the steel shell due to extrusion can be effectively prevented, and the welding yield of the steel shell button cell 10 is improved.

As shown in fig. 3 and 5, in one embodiment, the top cap assembly 100 includes an upper case 110, a first gasket 120, and a case cap 130, the case cap 130 is connected to the electrical core assembly 200, the first gasket 120 is stacked on a side of the case cap 130 facing away from the electrical core assembly 200, and the upper case 110 is stacked on a side of the first gasket 120 facing away from the case cap 130. It can be appreciated that after the cell assembly 200 is placed in the receiving cavity 312, the top cover assembly 100 can be welded to the placement opening 314 of the bottom case 300 without filling liquid, thereby improving the sealing performance of the steel-case button cell 10. However, if the sealing property of the top lid assembly 100 itself is poor, a problem of liquid leakage is likely to occur. In order to improve the sealing performance of the top cap assembly 100, in the present embodiment, the top cap assembly 100 includes an upper case 110, a first sealing gasket 120, and a case cap 130, the case cap 130 is connected to the electric core assembly 200, the first sealing gasket 120 is stacked on a side of the case cap 130 away from the electric core assembly 200, and the upper case 110 is stacked on a side of the first sealing gasket 120 away from the case cap 130. When the cap assembly 100 is welded to the placement opening 314 of the bottom chassis 300, the first gasket 120 can enhance the sealing property of the cap assembly 100, effectively preventing the electrolyte from leaking from the cap assembly 100. And first sealed 120 and shell cap 130 deviate from one side of electric core subassembly 200 and range upon range of, and upper shell 110 and one side that first sealed 120 deviates from shell cap 130 are range upon range of, and the steadiness that can press from both sides tightly and promote first sealed 120 through shell cap 130 and upper shell 110 to guarantee the sealed effect of first sealed 120, and then improve top cap subassembly 100's leakproofness.

Further, the housing cap 130 includes a main body 1320 and a protrusion 1340, the protrusion 1340 is connected to the main body 1320, and the first sealing pad 120 is sleeved on the protrusion 1340. It is understood that the first sealing gasket 120 is stacked on the side of the housing cap 130 away from the core assembly 200, and the upper housing 110 is stacked on the side of the first sealing gasket 120 away from the housing cap 130, so that the stability of the first sealing gasket 120 can be improved by clamping the housing cap 130 and the upper housing 110. However, the first gasket 120 is easily slid with respect to the housing cap 130 and the upper housing 110, and thus a gap is easily formed, which affects the sealability of the cap assembly 100. In order to further improve the stability of the first sealing gasket 120, in this embodiment, the housing cap 130 includes a main brim body 1320 and a protrusion 1340, the protrusion 1340 is connected to the main brim body 1320, the first sealing gasket 120 is sleeved on the protrusion 1340, and the first sealing gasket 120 is provided with a through hole, and the size of the through hole matches with the size of the protrusion 1340. When the top cover assembly 100 is closed, the visor main body 1320 can support the top cover assembly 100, the protrusion 1340 is sleeved on the first sealing gasket 120, and the protrusion 1340 can fix the first sealing gasket 120, so that the stability of the first sealing gasket 120 is further improved, and the sealing performance of the top cover assembly 100 is further improved.

As shown in fig. 3 and 5, in one embodiment, the sealing cover 400 includes a sealing cover main body 410 and a second sealing gasket 420, one side of the second sealing gasket 420 is attached to the sealing cover 400, and the side of the second sealing gasket 420 away from the sealing cover main body 410 is covered on the pouring outlet 316. It is understood that, after the electrolyte injection is completed, the sealing cap 400 is placed on the injection port 316 to perform the operation of closing the sealing cap 400, and then laser welding is performed to seal the steel-shell button cell 10. However, when the sealing cap 400 is closed, electrolyte is likely to remain at the joint of the sealing cap 400 and the injection port 316, a frosted surface is formed on the surface of the case at the joint of the sealing cap 400 and the injection port 316 after the case is soaked in the electrolyte, and the frosted layer is heated and evaporated to generate bubbles during laser high-temperature welding, which causes cold welding and poor air holes in the welding line. In addition, electrolyte on the surface of the steel shell remains, and mixed gas is evaporated and released during laser high-temperature welding, so that the color of the surface of a welding seam is poor. In order to improve the sealing performance of the sealing cover 400 after the sealing cover 400 is closed, in this embodiment, the sealing cover 400 includes a sealing cover main body 410 and a second sealing gasket 420, one side of the second sealing gasket 420 is attached to the sealing cover 400, and one side of the second sealing gasket 420 departing from the sealing cover main body 410 is covered on the liquid injection port 316. When the sealing cover 400 is closed, the second sealing gasket 420 is covered above the liquid injection port 316, so that the second sealing gasket 420 seals the liquid injection port 316, and part of the second sealing gasket 420 is in contact with the electrolyte; because the second gasket 420 has better sealing performance, the electrolyte is not easy to overflow from the injection port 316 after the sealing cover 400 is closed. Since the second gasket 420 is made of a soft material, the structural strength of the second gasket 420 is weak, and the second gasket is easily damaged to cause leakage. Because the sealing cover 400 comprises the sealing cover main body 410 and the second sealing gasket 420, the sealing cover main body 410 is a hard shell, one side of the second sealing gasket 420 is attached to the sealing cover 400, and the side of the second sealing gasket 420 departing from the sealing cover main body 410 is covered on the liquid injection port 316. When sealed lid 400 closed, sealed lid main part 410 can play the support fixed action to the sealed 420 that fills of second to improve sealed lid 400's structural strength, sealed lid main part 410 can further extrude the sealed 420 that fills of second simultaneously, improves the sealed 420 of second and annotates the inseparability between liquid mouth 316, thereby improves the sealed effect of the sealed 420 that fills of second. In addition, laser welding can form the welding seam with the junction of sealed lid 400 and drain pan 300 to the gap between sealed lid 400 and the bottom is sealed completely in the shutoff, prevents the emergence of weeping condition effectively, and the second is sealed fills up 420 and can completely cut off the contact between electrolyte and the sealed lid main part 410 effectively, prevents that electrolyte from to the problem that laser welding caused the interference between sealed lid 400 and the drain pan 300, thereby improves laser welding's stability, and then improves steel-shelled button cell 10's leakproofness.

As shown in fig. 3, in one embodiment, the core assembly 200 includes a core 210, a positive tab 220 and a negative tab 230, the core 210 is connected to the positive tab 220 and the negative tab 230, respectively, the positive tab 220 is connected to the top cover assembly 100, and the negative tab 230 is connected to the bottom case 300. In this embodiment, the bottom case 300 is provided with a positive electrode connecting portion, the top cover assembly 100 is provided with a negative electrode connecting portion, and after the battery cell assembly 200 is placed in the bottom case 300, the positive electrode tab 220 is connected to the positive electrode connecting portion, and the negative electrode tab 230 is connected to the negative electrode connecting portion, so that the core 210 can be respectively conducted to the top cover assembly 100 and the bottom case 300. Further, a first groove is formed in the bottom case 300, a second groove is formed in the top cover assembly 100, when the cell assembly 200 is placed in the accommodating cavity 312, the positive electrode tab 220 and the negative electrode tab 230 are bent, the bent positive electrode tab 220 is placed in the second groove, and the bent negative electrode tab 230 is placed in the first groove, so that the flatness between the cell assembly 200 and the bottom case 300 and the top cover assembly 100 is improved, and the structural stability of the steel shell button cell 10 is improved.

In one embodiment, the core 210 is a wound or laminated cell. In the embodiment, the winding body battery cell has better high and low temperature performance, can work at-55 ℃ to 75 ℃, can normally start discharging and charging at-55 ℃, does not deform and swell when the battery is at high temperature of 80 ℃, and does not have the danger of explosion. Further, the spiral winding type is adopted in the winding body cell, and sulfuric acid is completely adsorbed by the winding body cell partition plate, so that no flowing liquid exists in the winding body steel shell button cell 10, liquid leakage does not occur even if the winding body steel shell button cell is inverted, and the leakage-proof effect of the steel shell button cell 10 is improved. The surface of the pole piece in the laminated cell is smooth, tension influence is avoided in the length direction, the pole piece and the diaphragm are in full contact, and therefore the consistency of interface reaction in the cell is improved.

In one embodiment, the bottom case 300 is provided with an automatic backflow structure, and the liquid injection port 316 is opened in the automatic backflow structure. In this embodiment, the automatic backflow structure is step-shaped, that is, there is a height difference between the automatic backflow structure and the plane where the liquid injection port 316 is located, and even if the electrolyte overflows from the liquid injection port 316, the automatic backflow structure can also enable the overflowing electrolyte to flow back into the casing, so as to effectively prevent the electrolyte in the casing from creeping into the casing, so that the overflowing electrolyte cannot reach the sealing cover 400, thereby improving the neatness of the sealing cover 400 and the stability of the sealing and welding of the steel-shell button cell 10. Further, when sealing lid 400 closes the lid, sealing lid 400 is connected with automatic backflow structure, makes automatic backflow structure can prevent sealing lid 400 when closing the lid with annotate the electrolyte contact of liquid mouth 316, can prevent that sealing lid 400 from sliding into the casing and taking electrolyte out when the assembly to further improve the clean and tidy nature of sealing lid 400 department, further improve steel-shelled button cell 10 seal welding's stability.

As shown in fig. 6, in one embodiment, the automatic backflow structure 700 includes a housing 710 and a sealing cover plate 720, the housing 710 includes a sealing housing 712 and an inverted housing 714, the inverted housing 714 is connected to the sealing housing 712, the inverted housing 714 is provided with an automatic backflow step 7142 and a liquid injection portion 7144, the liquid injection portion 7144 is connected to the automatic backflow step 7142, the automatic backflow step 7142 is connected to the sealing housing 712, and the liquid injection portion 7144 is provided with a liquid injection port 7146; the sealing cover plate 720 is disposed on the liquid injection portion 7144, and the sealing cover plate 720 is connected to the automatic backflow step 7142.

In this embodiment, the automatic backflow structure 700 includes a housing 710 and a sealing cover plate 720, the inverted housing 714 is connected to the sealing housing 712, the inverted housing 714 is provided with an automatic backflow step 7142 and an injection part 7144, the injection part 7144 is connected to the automatic backflow step 7142, the injection part 7144 is provided with an injection port 7146, the injection port 7146 is used for injecting electrolyte, and the electrolyte is injected or discharged through the automatic backflow step 7142; further, a sealing cover plate 720 is provided to cover the liquid injection portion 7144, and the sealing cover plate 720 is connected to the automatic backflow step 7142. Because the step-shaped structure of the automatic backflow step 7142, namely the height difference exists between the plane where the automatic backflow step 7142 and the liquid injection port 7146 are located, even if electrolyte overflows from the liquid injection port 7146, the automatic backflow step 7142 can also enable the overflowing electrolyte to flow back into the shell 710, so that the electrolyte in the shell 710 is effectively prevented from climbing, the overflowing electrolyte cannot reach the sealing cover plate 720, the tidiness of the sealing cover plate 720 is improved, and the stability of the sealing welding of the steel shell button cell is improved. Furthermore, the automatic backflow step 7142 not only can effectively prevent electrolyte in the housing 710 from creeping, so that the overflowed electrolyte cannot reach the sealing cover plate 720, but also can serve as a pressure-bearing step of the sealing cover plate 720. Because sealed apron 720 lid is located notes liquid portion 7144, sealed apron 720 is connected with automatic backward flow step 7142, makes automatic backward flow step 7142 can prevent that sealed apron 720 from closing the electrolyte contact of lid time with annotating liquid mouth 7146, can prevent promptly that sealed apron 720 from sliding into in the casing 710 and taking electrolyte out when the assembly to further improve the clean and tidy nature of sealed apron 720 department, further improve the sealed welded stability of steel-shelled button cell.

As shown in fig. 7, in one embodiment, the self-reflow structure 700 further includes a gasket 730, and the gasket 730 is attached to the self-reflow step 7142. It can be understood that, although the overflowed electrolyte can flow back into the case 710 when passing through the automatic backflow step 7142 due to the step-like structure of the automatic backflow step 7142, that is, the height difference exists between the automatic backflow step 7142 and the plane where the liquid injection port 7146 is located, a small amount of electrolyte is likely to remain on the surface of the automatic backflow step 7142 after the electrolyte flows back into the case 710. In order to prevent that sealed apron 720 is infected with remaining electrolyte when closing the lid, in this embodiment, automatic backflow structure 700 still includes sealed pad 730, sealed pad 730 laminates in automatic backward flow step 7142, sealed pad 730 can play better isolated and sealed effect to electrolyte to sealed apron 720 is infected with remaining electrolyte when closing the lid, guarantees the clean and tidy nature after sealed apron 720 closes the lid, and then improves steel-shelled button cell seal welding's stability. In addition, the sealing gasket 730 can also play a better insulating role, thereby improving the performance stability of the steel-shell button cell.

Further, the gasket 730 has a larger orthographic area than the liquid injection part 7144. It can be understood that sealed pad 730 can play better isolated and sealed effect to electrolyte to sealed apron 720 is infected with remaining electrolyte when closing the lid, guarantees the clean and tidy nature of sealed apron 720 after closing the lid, and then improves steel-shelled button cell seal welding's stability. In addition, the gasket 730 can also perform a better insulating function. In order to further improve the adhesion tightness between the gasket 730 and the automatic backflow structure 7142 and prevent leakage of the electrolyte, in the present embodiment, the orthographic area of the gasket 730 is larger than the orthographic area of the liquid injection portion 7144, so that the gasket 730 can completely seal the liquid injection port 7146 and the liquid injection portion 7144 around the liquid injection port 7146, thereby further improving the sealing performance of the gasket 730 and further improving the anti-creeping effect of the automatic backflow structure 700.

Further, the sealing cap plate 720 is half-wrapped in the sealing gasket 730. It can be understood that the sealing cover plate 720 covers the liquid injection portion 7144, the sealing cover plate 720 is connected to the self-reflow step 7142, and if the sealing cover plate 720 directly contacts the self-reflow step 7142, the edge of the sealing cover plate 720 is easily contaminated by the overflowing electrolyte. In order to further prevent the sealing cover plate 720 from contacting with the electrolyte, in this embodiment, the sealing cover plate 720 is half-wrapped in the sealing gasket 730, so as to avoid the direct contact between the sealing cover plate 720 and the dynamic return step, effectively prevent the sealing cover plate 720 from contacting with the electrolyte, and meanwhile, the sealing gasket 730 can better prevent the sealing cover plate 720 from sliding into the liquid injection port 7146 and taking out the electrolyte when the sealing cover plate is closed, thereby improving the safety of the sealing cover plate 720 when the sealing cover plate is closed. In addition, the sealing cover plate 720 is half wrapped in the sealing gasket 730, and the sealing gasket 730 can also play a good buffering role on the sealing cover plate 720, so that the stability of the automatic backflow structure 700 is improved.

As shown in fig. 7, in one embodiment, the automatic reflow structure 700 further includes a sealing hot-melt adhesive ring 740, and the sealing hot-melt adhesive ring 740 is sleeved between the sealing cover plate 720 and the automatic reflow step 7142. It is understood that after the sealing cover plate 720 is covered on the liquid filling part 7144, a groove is formed between the circumference of the sealing cover plate 720 and the sealing housing 712. In order to improve the sealing performance and the insulating performance at the sealing cover plate 720, in this embodiment, the automatic backflow structure 700 further includes a sealing hot-melt rubber ring 740, the sealing hot-melt rubber ring 740 is sleeved between the sealing cover plate 720 and the automatic backflow step 7142, the automatic backflow step 7142 is connected with the sealing housing 712, and the sealing hot-melt rubber ring 740 can improve the sealing performance between the sealing cover plate 720 and the automatic backflow step 7142 and improve the sealing performance between the sealing cover plate 720 and the sealing housing 712. In addition, the sealing hot-melt rubber ring 740 has good insulation performance, and the sealing cover plate 720 and the automatic backflow step 7142 are sleeved with the sealing hot-melt rubber ring 740, so that the insulation performance of the automatic backflow structure 700 can be effectively improved.

In one embodiment, the height of the auto-reflow step 7142 is equal to the sum of the height of the sealing cover 720 and the height of the gasket 730. It can be understood that the automatic backflow step 7142 not only can effectively prevent electrolyte in the case 710 from creeping, so that the overflowed electrolyte cannot reach the sealing cover plate 720, but also the automatic backflow step 7142 can also serve as a pressure-bearing step of the sealing cover plate 720. Because sealed apron 720 lid is located notes liquid portion 7144, sealed apron 720 is connected with automatic backward flow step 7142, makes automatic backward flow step 7142 can prevent that sealed apron 720 from closing the electrolyte contact of lid time with annotating liquid mouth 7146, can prevent promptly that sealed apron 720 from sliding into in the casing 710 and taking electrolyte out when the assembly to further improve the clean and tidy nature of sealed apron 720 department, further improve the sealed welded stability of steel-shelled button cell. However, if the sealing cover plate 720 is disposed on the liquid injection part 7144 and then the sealing cover plate 720 is higher than the sealing case 712 or lower than the sealing case 712, the steel-case button cell case 710 is not flat. In order to improve the flatness of the steel-casing button cell housing 710, in the embodiment, the height of the automatic backflow step 7142 is the same as the sum of the heights of the sealing cover plate 720 and the gasket 730, so that the sealing cover plate 720 is covered on the liquid injection part 7144, that is, the sealing cover plate 720 and the sealing housing 712 are in the same plane after the sealing cover plate is covered, thereby effectively improving the flatness of the steel-casing button cell housing 710.

In one embodiment, the angle of inclination of the auto-reflow step 7142 is 20 to 80 degrees. It can be understood that, due to the step-shaped structure of the automatic backflow step 7142, that is, the height difference exists between the plane where the automatic backflow step 7142 and the liquid injection port 7146 are located, even if the electrolyte overflows from the liquid injection port 7146, the automatic backflow step 7142 can also enable the overflowing electrolyte to flow back into the shell 710, so that the electrolyte in the shell 710 is effectively prevented from creeping, the overflowing electrolyte cannot reach the sealing cover plate 720, the tidiness of the sealing cover plate 720 is improved, and the stability of the sealing welding of the steel shell button cell is improved. However, if the inclination angle of the automatic backflow step 7142 is too small, the liquid-climbing prevention effect is likely to fail; if the inclination angle of the automatic backflow step 7142 is too large, the area of the automatic backflow step 7142 is easily small, the pressure bearing effect is poor, and the closing of the sealing cover plate 720 is not facilitated. In order to improve the anti-creeping liquid effect of the automatic backflow step 7142, in this embodiment, the inclination angle of the automatic backflow step 7142 is 20-80 degrees, so that the automatic backflow step 7142 has a good anti-creeping liquid effect, and meanwhile, the inclination angle of 20-80 degrees can enable the opening direction area of the automatic backflow step 7142 to be larger than the area of the sealing cover plate 720, thereby being beneficial to the cover closing of the sealing cover plate 720, and being beneficial to improving the pressure bearing effect of the automatic backflow step 7142 on the sealing cover plate 720.

In one embodiment, the diameter of the sealing cap plate 720 is 3mm to 4 mm. It can be understood that the sealing cover plate 720 of the liquid filling port 7146 of the existing steel-shell button cell has a diameter of 12mm, the length of the sealing welding bead after liquid filling is 38mm, the sealing welding bead is long, which easily prolongs the process time, and the shell 710 has long welding heating time, which easily heats the electrolyte to generate bubbles, thereby affecting the performance of the steel-shell button cell. In order to optimize the length of the sealing weld bead after the liquid injection of the automatic backflow structure 700, shorten the heating time and reduce bubbles generated by heating the electrolyte, in the embodiment, the diameter of the sealing cover plate 720 is 3 mm-4 mm, compared with the length of the sealing weld bead after the liquid injection of the existing steel shell button cell, the length of the sealing weld bead after the liquid injection is shortened from 37.8mm to 11mm, and the length of the sealing weld bead is reduced by 26.8 mm; the welding heating time is shortened from 8.5S/PCS to 3.5S/PCS, and the welding time is shortened by 5S, so that the length of a sealing weld bead is effectively reduced, the heating time is shortened, the electrolyte is prevented from being heated to generate bubbles, and the stability of the automatic backflow structure 700 during sealing is further improved.

In one embodiment, the sealing cover plate 720 includes a cover plate body and an anti-adhesive liquid layer coupled to the cover plate body. It is understood that a sealing cover plate 720 is provided to cover the liquid injection part 7144, and the sealing cover plate 720 is connected to the self-refluxing step 7142. Due to the step-shaped structure of the automatic backflow step 7142, that is, the height difference exists between the plane where the automatic backflow step 7142 and the liquid injection port 7146 are located, even if the electrolyte overflows from the liquid injection port 7146, the automatic backflow step 7142 can enable the overflowing electrolyte to flow back into the shell 710. However, after the electrolyte flows back into the case 710, a residual part of the electrolyte is easily adhered to the sealing cover plate 720, so that a small amount of electrolyte is easily overflowed, and the welding of the steel-shell button cell is affected. In order to prevent the electrolyte from flowing back into the case 710, a small amount of the electrolyte still remains to be adhered to the sealing cover plate 720, in the present embodiment, the sealing cover plate 720 includes a cover plate main body and an anti-sticking liquid layer connected to the cover plate main body, and the anti-sticking liquid layer can effectively prevent the electrolyte from being adhered to the sealing cover plate 720, thereby further improving the anti-creeping effect of the automatic backflow structure 700.

As shown in fig. 3 and 5, in one embodiment, the steel-can button cell 10 further includes a first insulating gasket 500, and the first insulating gasket 500 is installed between the cell assembly 200 and the bottom can 300. It can be understood that the battery cell is easy to contact with the tab and the steel shell to generate friction when the battery cell shrinks in the repeated charging and discharging process, and the abnormal damage condition of the diaphragm can be generated by vibration and impact in the use process. In order to improve the structural stability of the steel-shell button cell 10 in the charging and discharging process, in this embodiment, the steel-shell button cell 10 further includes a first insulating gasket 500, the first insulating gasket 500 is installed between the cell assembly 200 and the bottom shell 300, so as to eliminate the friction generated by the contact between the cell and the negative electrode tab 230 and the bottom shell 300 when the cell shrinks in the repeated charging and discharging process, and the damage to the diaphragm caused by the shock impact of the steel-shell button cell 10 in the using process, thereby effectively prolonging the service life of the steel-shell button cell 10, and ensuring the performance stability of the steel-shell button cell 10 under extreme conditions such as shock impact.

As shown in fig. 3 and 5, in one embodiment, the steel-can button cell 10 further includes a second insulating gasket 600, and the second insulating gasket 600 is installed between the core assembly 200 and the top cap assembly 100. It can be understood that the battery cell is easy to contact with the tab and the steel shell to generate friction when the battery cell shrinks in the repeated charging and discharging process, and the abnormal damage condition of the diaphragm can be generated by vibration and impact in the use process. In order to improve the structural stability of the steel-casing button cell 10 during the charging and discharging processes, in this embodiment, the steel-casing button cell 10 further includes a second insulating spacer 600, the second insulating spacer 600 is installed between the cell assembly 200 and the top cap assembly 100, so as to eliminate the friction generated by the contact between the cell and the positive electrode tab 220 and the contact between the cell and the top cap assembly 100 when the cell shrinks during the repeated charging and discharging processes, and the damage to the diaphragm caused by the shock impact during the use of the steel-casing button cell 10, thereby effectively prolonging the service life of the steel-casing button cell 10, and ensuring the performance stability of the steel-casing button cell 10 under extreme conditions such as shock impact

As shown in fig. 4, in one embodiment, the bottom chassis 300 is provided with a two-dimensional code area 310. In this embodiment, the two-dimensional code can be sprayed in the two-dimensional code area 310 of the bottom case 300, the two-dimensional code can distinguish the steel-case button cell 10, and the two-dimensional code has high-density codes, and has a large information capacity, a wide coding range and strong fault-tolerant capability, and has the advantages of error correction function and high decoding reliability, and the steel-case button cell 10 can be identified and recorded by the two-dimensional code, so that a refined production mode of two-dimensional code scanning management can be adopted in the process of the steel-case button cell 10, and the test and inspection data of each link in the process can be automatically stored in the MES system after scanning the code, thereby improving the reliability of each performance index output of each finished steel-case button cell 10, and simultaneously improving the production efficiency and the yield.

Compared with the prior art, the invention has at least the following advantages:

1. according to the preparation method of the steel-shell button cell, the top cover assembly, the bottom shell and the sealing cover are punched and formed, wherein the bottom shell is punched and formed with the accommodating cavity, the placing opening and the liquid injection opening, the accommodating cavity is used for placing the electric core assembly, the liquid injection opening is punched and formed in the bottom shell instead of the top cover assembly, and the liquid injection opening and the placing opening are respectively formed in two sides of the bottom shell, so that the electric core assembly placing operation and the liquid injection operation are respectively performed at two different parts of the bottom shell, the situation that partial electrolyte is remained in the placing opening after the electrolyte is injected into the electric core is prevented, and the stability of the cover combining and welding operation of the steel-shell button cell is improved.

2. According to the preparation method of the steel-shell button cell, the positive pole tab in the cell assembly is welded to the top cover assembly, the negative pole tab is welded to the bottom shell, the cell assembly is placed into the bottom shell, the top cover assembly and the bottom shell are closed, and then the top cover assembly and the edge of the bottom shell are subjected to first laser welding operation, so that the top cover assembly and the bottom shell are sealed. Because the laser welding operation between top cap subassembly and the drain pan is accomplished before annotating the liquid for top cap subassembly and drain pan can eliminate the influence of remaining electrolyte effectively, thereby improve steel-shell button cell's laser welding stability effectively, improve steel-shell button cell's leakproofness simultaneously.

3. According to the preparation method of the steel-shell button cell, after the cell to be injected is obtained, the cell to be injected is subjected to electrolyte injection operation under the vacuum condition, then the sealing cover is covered on the electrolyte injection port, and the sealing cover and the bottom shell are subjected to second laser welding operation under the vacuum condition. The electrolyte injection operation and the sealing welding operation are all completed under the vacuum condition, so that the stability of the electrolyte injection operation is effectively guaranteed, the cleanness and tidiness of the periphery of the liquid injection port are improved, meanwhile, the interference of external conditions on the second laser welding operation is prevented, and the sealing performance of the steel shell button cell is improved.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.