Differential thickness steel shell for battery and production method thereof

Abstract

The present invention discloses a battery steel shell with differential thickness and a production method thereof, wherein the battery steel shell with differential thickness comprises: a barrel body, a sealing end, and a transition section between the barrel body and the sealing end; wherein the differential thickness score line of the battery steel shell with differential thickness is located on the barrel body. The battery steel shell with differential thickness disclosed by the present invention sets the differential thickness score line on the barrel body, and since the transition section is located between the barrel body and the sealing end, the differential thickness score line and the transition line are separated, thereby improving the strength of the transition section and effectively reducing the probability of the battery bulging in the easily deformed area when the battery is sealed and curled; at the same time, the probability of the battery bulging in the easily deformed area when the battery is sealed and curled can be reduced by only changing the position of the differential thickness score line, without increasing the workstation and mold structure, and without increasing the production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of battery shells, and more specifically, to a differential thickness steel shell for a battery and a production method thereof. Background Art

[0002] Due to its significant advantages, the difference thickness steel shell is gradually being widely used in batteries. Figure 1 As shown, the differential thickness steel shell includes: a barrel body 13, a positive terminal 14 located at the bottom end of the barrel body 13, a sealing end 11 located at the top end of the barrel body 13, and a transition section 12 located between the barrel body 13 and the sealing end 11; wherein, the barrel body 13 is thinner, called a thin-walled section, and the thickness t1 of the thin-walled section is less than the thickness of the raw material; the sealing end 11 is thicker, called a thick-walled section, and the thick-walled section retains the thickness of the raw material, that is, the thickness t2 of the thick-walled section is greater than or equal to the material thickness. Because the differential thickness steel shell has a thin-walled section and a thick-walled section, and is determined by a multi-station stretching process, there is an objective joint mark between the thin-walled section and the thick-walled section, that is, a differential thickness score line 17, and the differential thickness score line 17 is located in the transition section 12.

[0003] The battery production method is as follows: first fill the steel shell with different thickness, then perform wire rolling on the steel shell with different thickness. The wire rolling position is generally at the transition section 12 to form a wire rolling groove 15. Figure 2 As shown, the negative electrode seal and current collector assembly are then installed, and finally the seal is crimped, as shown in FIG. Figure 2 During the sealing and curling process, a large axial pressure will be generated, and the difference in thickness of the steel shell itself will weaken the compressive strength of the steel shell. The location of the difference in thickness score line 17, that is, the transition section 12 is the weakest position of the entire difference in thickness steel shell. The area near the difference in thickness score line 17 is the easy deformation area 16. When the sealing and curling is performed, it is easy to produce a battery bulging phenomenon in the easy deformation area 16, resulting in serious defects in the battery.

[0004] In summary, how to design a battery steel shell with a differential thickness to improve the strength of the transition section, thereby reducing the probability of battery bulging in the deformable zone 16 during sealing and curling, is a problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a battery steel shell with a differential thickness, so as to improve the strength of the transition section, thereby reducing the probability of the battery bulging in the easily deformed area when the battery is sealed and curled. Another purpose of the present invention is to provide a method for producing a battery steel shell with a differential thickness.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A battery steel shell with differential thickness comprises: a barrel body, a sealing end, and a transition section between the barrel body and the sealing end; wherein the differential thickness score line of the battery steel shell with differential thickness is located on the barrel body.

[0008] Preferably, the distance between the differential thickness score line and the transition section is 1.5 mm-4.0 mm.

[0009] Preferably, the distance between the thickness difference score line and the top of the sealing end is 5.0 mm-7.5 mm.

[0010] Preferably, the thickness of the barrel body is 0.16mm-0.20mm, and the thickness of the sealing end is 0.25mm-0.28mm.

[0011] The differential thickness steel shell for batteries provided by the present invention has a differential thickness score line set on the barrel body. Since the transition section is located between the barrel body and the sealing end, the differential thickness score line and the transition line are separated, thereby improving the strength of the transition section, that is, improving the strength of the steel shell at the position where the rolling groove is located when the battery is made, and effectively reducing the probability of the battery bulging in the easy deformation area when the battery is sealed and curled.

[0012] At the same time, the differential thickness steel shell for the battery provided by the present invention can reduce the probability of battery bulging in the easily deformed area when the battery is sealed and curled simply by changing the position of the differential thickness score line, without adding workstations and mold structures, and will not increase production costs.

[0013] Based on the above-mentioned battery steel shell with differential thickness, the present invention provides a method for producing a battery steel shell with differential thickness, and the method for producing a battery steel shell with differential thickness comprises the steps of:

[0014] 1) thinning and stretching a workpiece so that the workpiece has a first thick-walled section and a first thin-walled section, and a thickness difference line is formed between the first thick-walled section and the first thin-walled section;

[0015] 2) forming the barrel body so that the workpiece has a second thick-walled section and a second thin-walled section, and a transition section is provided between the second thick-walled section and the second thin-walled section;

[0016] 3) Sealing end molding;

[0017] 4) Positive terminal forming;

[0018] 5) Punching shell waste;

[0019] The material volume of the second thin-walled section is greater than that of the first thin-walled section, and the thickness difference score line is located in the second thin-walled section.

[0020] Preferably, the distance between the differential thickness score line and the transition section is 1.5 mm-4.0 mm.

[0021] Preferably, the distance between the differential thickness score line and the top of the differential thickness steel shell for the battery is 5.0 mm to 7.5 mm.

[0022] Preferably, the thickness of the second thin-wall section is 0.16 mm-0.20 mm, and the thickness of the second thick-wall section is 0.25 mm-0.28 mm.

[0023] Preferably, the step 1) further includes the following steps:

[0024] 11) stretching the workpiece without thinning for the first time;

[0025] 12) stretching the workpiece without thinning for a second time;

[0026] 13) stretching the workpiece without thinning for a third time;

[0027] 14) The workpiece is stretched without thinning for a fourth time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0029] Figure 1 A schematic diagram of the structure of a battery with a different thickness steel shell provided by the prior art;

[0030] Figure 2 A schematic diagram of a rolling line and a sealing crimping edge in a battery production method provided by the prior art;

[0031] Figure 3 A schematic diagram of the structure of a steel shell with a difference in thickness for a battery provided in an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of a method for producing a steel shell with a differential thickness for a battery provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] like Figure 3As shown, the battery differential thickness steel case provided by the embodiment of the present invention comprises: a barrel body 24, a sealing end 21, and a transition section 22 located between the barrel body 24 and the sealing end 21; wherein, the differential thickness score line 23 of the battery differential thickness steel case is located at the barrel body 24. It can be understood that the differential thickness score line 23 is located at the side of the transition section 22 close to the positive terminal of the battery differential thickness steel case.

[0035] The battery steel shell with differential thickness provided in the embodiment of the present invention has the differential thickness score line 23 set on the barrel body 24. Since the transition section 22 is located between the barrel body 24 and the sealing end 21, the differential thickness score line 23 and the transition line 22 are separated, thereby improving the strength of the transition section 22 and effectively reducing the probability of the battery bulging in the easy deformation area when the battery is sealed and curled. The easy deformation area is Figure 2 The deformable zone 16 is shown in FIG.

[0036] At the same time, the battery steel shell with differential thickness provided in the embodiment of the present invention can reduce the probability of battery bulging in the easily deformable area when the battery is sealed and curled by simply changing the position of the differential thickness score line 23, without adding workstations and mold structures, and without increasing production costs. Figure 2 The deformable zone 16 is shown in FIG.

[0037] In the above-mentioned battery steel shell with differential thickness, the distance between the differential thickness score line 23 and the transition section 22 is selected according to actual needs, and the embodiment of the present invention does not limit this. Preferably, the distance between the above-mentioned differential thickness score line 23 and the transition section 22 is 1.5mm-4.0mm. Figure 3 As shown, the distance between the thickness difference line 23 and the transition section 22 is L1, L1 = 1.5mm-4.0mm. Of course, the distance between the thickness difference line 23 and the transition section 22 can also be selected to be other values ​​according to actual needs, and is not limited to this.

[0038] In the above-mentioned battery steel shell, the specific position of the thickness difference score line 23 is designed according to actual needs. Preferably, the distance between the thickness difference score line 23 and the top of the sealing end 21 is 5.0mm-7.5mm. Figure 3 As shown, the distance between the thickness difference score line 23 and the top of the sealing end 21 is L2, L2 = 5.0mm-7.5mm. Of course, the distance between the thickness difference score line 23 and the top of the sealing end 21 can also be selected to be other values, and is not limited to the above embodiment.

[0039] Preferably, the thickness of the barrel body 24 is 0.16mm-0.20mm, and the thickness of the sealing end 21 is 0.25mm-0.28mm. Of course, the thickness of the barrel body 24 and the sealing end 21 can be appropriately adjusted according to actual needs, and are not limited thereto.

[0040] Based on the battery thickness difference steel shell provided in the above embodiment, the present invention also provides a method for producing the battery thickness difference steel shell, such as Figure 4 As shown, the production method of the battery thickness difference steel shell specifically includes the following steps:

[0041] S01) thinning and stretching the workpiece so that the workpiece has a first thick-walled section 31 and a first thin-walled section 32, and a thickness difference score line 37 is formed between the first thick-walled section 31 and the first thin-walled section 32:

[0042] Specifically, the position of the thickness difference score line 37 is adjusted by adjusting the height of the first thick-walled section 31 .

[0043] S02) The barrel body is formed so that the workpiece has a second thick-walled section 33 and a second thin-walled section 34, and a transition section 38 is provided between the second thick-walled section 33 and the second thin-walled section 34:

[0044] It can be understood that the material volume of the second thin-walled section 34 is greater than the material volume of the first thin-walled section 32 , thus ensuring that the differential thickness score line 37 is located in the second thin-walled section 34 .

[0045] Specifically, the first thin-walled section 32 is further stretched until the cylinder is straightened and formed, and the positive electrode blank is pre-punched, and the thickness of the second thin-walled section 34 is controlled to be 0.16 mm-0.20 mm.

[0046] S03) Sealing end molding:

[0047] It can be understood that this station only forms the sealing end of the second thick-walled section 33 and does not change the position of the differential thickness score line 37 .

[0048] After the sealing end is formed, the workpiece has a third thick-walled section 35 and a third thin-walled section 36 . The thickness of the third thick-walled section 35 is controlled to be 0.25 mm-0.28 mm, and the third thin-walled section 36 still retains the shape and size of the second thin-walled section 34 .

[0049] S04) Positive terminal forming:

[0050] Specifically, the positive terminal molding can be completed once or in two or more steps. Preferably, the positive terminal molding includes the steps of positive terminal pre-molding and positive terminal molding.

[0051] S05) Punching shell waste:

[0052] Once the waste is cut off, production is complete.

[0053] It should be noted that the rolling groove of the battery is in the transition section 38 of the battery's steel shell with different thickness.

[0054] The method for producing a differential thickness steel shell for a battery provided in an embodiment of the present invention sets the differential thickness score line 37 in the second thin-walled section 34, and finally the differential thickness score line 37 is located in the barrel body, thereby separating the differential thickness score line 37 and the transition line 38, thereby improving the strength of the transition line 38 and effectively reducing the probability of the battery bulging in the easy deformation zone when the battery is sealed and curled. The easy deformation zone is Figure 2 The deformable zone 16 is shown in FIG.

[0055] At the same time, the method for producing a battery steel shell with a differential thickness provided in the embodiment of the present invention can reduce the probability of battery bulging in the easily deformable area during sealing and curling by simply changing the position of the differential thickness score line 37, without adding workstations and mold structures, and without increasing production costs. Figure 2 The deformable zone 16 is shown in FIG.

[0056] Preferably, the distance between the thickness difference line 37 and the transition section 38 is 1.5 mm to 4.0 mm. Of course, the distance between the thickness difference line 37 and the transition section 38 can also be selected to be other values ​​according to actual needs, and is not limited thereto.

[0057] Preferably, the distance between the thickness difference score line 37 and the top of the thickness difference steel shell for the battery is 5.0 mm to 7.5 mm. Figure 4 As shown, the distance between the thickness difference line 37 and the top of the battery thickness difference steel shell is L2, L2 = 5.0mm-7.5mm. Of course, the distance between the thickness difference line 37 and the top of the battery thickness difference steel shell can also be selected to be other values, and is not limited to the above embodiment.

[0058] Preferably, in the production method of the differential thickness steel shell for the battery, the thickness of the second thin-walled section 34 is 0.16 mm-0.20 mm, and the thickness of the second thick-walled section 33 is 0.25 mm-0.28 mm. Of course, the thickness values ​​of the second thin-walled section 34 and the second thick-walled section 33 can also be appropriately adjusted according to actual needs, and are not limited thereto.

[0059] The specific steps of the above-mentioned thinning and stretching are designed according to actual needs. Preferably, the step S01) further includes the following steps:

[0060] S011) stretching the workpiece without thinning for the first time;

[0061] S012) stretching the workpiece without thinning for the second time;

[0062] S013) stretching the workpiece without thinning for the third time;

[0063] S014) The workpiece is stretched without thinning for the fourth time.

[0064] It can be understood that non-thinning stretching means that there is no thickness difference in the wall thickness of the entire workpiece after stretching. The specific stretching coefficient of each non-thinning stretching is set according to actual needs, and the embodiment of the present invention does not limit this.

[0065] The above four steps can be performed in four stations respectively. Specifically, the first non-thinning and stretching workpiece is performed in the first non-thinning and stretching station, the second non-thinning and stretching workpiece is performed in the second non-thinning and stretching station, the third non-thinning and stretching workpiece is performed in the third non-thinning and stretching station, and the fourth non-thinning and stretching workpiece is performed in the fourth non-thinning and stretching station. Of course, a transition station can also be set between two adjacent stations, for example, a transition station is set between the station that completes step S011 and the station that completes step S012, and the embodiment of the present invention does not limit this.

[0066] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery steel shell with a differential thickness, comprising: A barrel body, a sealing end, and a transition section between the barrel body and the sealing end; characterized in that the differential thickness score line of the battery differential thickness steel shell is located on the barrel body, and the differential thickness score line is the joint between the thin-walled section and the thick-walled section obtained by thinning and stretching in the process of producing the battery differential thickness steel shell; the differential thickness score line is located on the side of the transition section close to the positive end of the battery differential thickness steel shell; the transition section is used to set the rolling line groove.

2. The battery steel shell with differential thickness according to claim 1, characterized in that: The distance between the thickness difference score line and the transition section is 1.5 mm to 4.0 mm.

3. The battery steel shell with differential thickness according to claim 1, characterized in that: The distance between the thickness difference score line and the top of the sealing end is 5.0 mm to 7.5 mm.

4. The battery steel shell with differential thickness according to claim 1, characterized in that: The thickness of the barrel body is 0.16mm-0.20mm, and the thickness of the sealing end is 0.25mm-0.28mm.

5. A method for producing a steel shell with a difference in thickness for a battery, characterized in that: Includes steps: 1) thinning and stretching a workpiece so that the workpiece has a first thick-walled section and a first thin-walled section, and a thickness difference score line is provided between the first thick-walled section and the first thin-walled section, and the thickness difference score line is a joint mark between the first thick-walled section and the first thin-walled section; 2) forming the barrel body so that the workpiece has a second thick-walled section and a second thin-walled section, and a transition section is provided between the second thick-walled section and the second thin-walled section; 3) Sealing end molding; 4) Positive terminal forming; 5) Punching shell waste; Among them, the material volume of the second thin-walled section is greater than the material volume of the first thin-walled section, the differential thickness mark line is located in the second thin-walled section, and the differential thickness mark line is located on the side of the transition section close to the positive end of the differential thickness steel shell for the battery; the transition section is used to set the rolling line groove.

6. The production method according to claim 5, characterized in that The distance between the thickness difference score line and the transition section is 1.5 mm to 4.0 mm.

7. The production method according to claim 5, characterized in that: The distance between the thickness difference score line and the top of the thickness difference steel shell for the battery is 5.0 mm to 7.5 mm.

8. The production method according to claim 5, characterized in that: The thickness of the second thin-wall section is 0.16 mm-0.20 mm, and the thickness of the second thick-wall section is 0.25 mm-0.28 mm.

9. The production method according to claim 5, characterized in that: The step 1) also includes the following steps: 11) stretching the workpiece without thinning for the first time; 12) stretching the workpiece without thinning for a second time; 13) stretching the workpiece without thinning for a third time; 14) The workpiece is stretched without thinning for a fourth time.

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