Winding needle sleeve processing structure for cylindrical battery cell and battery cell product

Abstract

The utility model relates to the technical field of battery cells, in particular to a winding needle sleeve processing structure for a cylindrical cell and a battery cell product. The winding needle sleeve processing structure comprises N sub winding needles, the sleeves correspond to the sub winding needles in shape, the outer side of each sub winding needle is movably sleeved with one sleeve, and the sleeves are connected to form a columnar winding drum; the diaphragm is wound on the outer surface of the sleeve along the circumferential side of the winding drum; the battery cell strip is arranged between the interlayers of the diaphragm; according to the utility model, the sleeve is arranged, so that the diaphragm core pulling can be effectively avoided when the winding needle is unwound, meanwhile, the sleeve is reserved at the central hole of the battery cell, the central structure can be stabilized, and the influence on the electrochemical performance and the safety performance of the battery cell due to central hole collapse in the subsequent circulation process of the battery cell is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of battery cores, and in particular to a winding needle sleeve process structure for cylindrical cores and a battery core product. Background Art

[0002] The existing winding equipment and process structure of cylindrical batteries in actual production and application are as follows: Figure 1 As shown, in the prior art, the diaphragm 2 is first introduced into the middle of the two-phase fitting rectangular surfaces of the sub-winding needle 1, and then the first half winding needle 11 and the second half winding needle 12 arranged on the left and right clamp the diaphragm 2. After pre-winding 1-2 weeks to fix the position of the diaphragm 2, the battery cell strip 3 including the negative electrode strip 32 and the positive electrode strip 31 are rolled in turn. After the winding of the battery cell is completed, the winding needle is pulled out.

[0003] There are two main problems with the battery cell manufacturing process in the prior art: first, during the winding process of the battery cell, at the moment the winding needle is pulled out, the friction between the winding needle and the diaphragm 2 will cause the winding needle to bring out the diaphragm, resulting in a decrease in the winding yield; second, in the existing battery cell structure, the cylindrical battery cell will have a center hole with a diameter of about 4 mm after winding. In the later battery cell cycle process, due to the expansion of the electrode piece, a large stress will be generated in the battery cell. The existence of this stress will cause the center hole to collapse, causing the battery cell structure to deform, affecting the battery cell's cycle and safety performance. Utility Model Content

[0004] The purpose of the utility model is to provide a winding needle sleeve process structure for cylindrical battery cells to solve the above technical problems;

[0005] The utility model also aims to provide a battery cell product to solve the above technical problems.

[0006] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0007] A winding needle sleeve process structure for a cylindrical battery cell, comprising:

[0008] N sub-winding needles;

[0009] A sleeve corresponding to the shape of the sub-winding needle, wherein the outer side of each sub-winding needle is movably sleeved with the sleeve, and the sleeves are connected and arranged to form a cylindrical winding drum;

[0010] a diaphragm, wound around the outer surface of the sleeve along the circumference of the reel;

[0011] The battery strip is arranged between the interlayers of the separator;

[0012] Wherein N is a positive integer greater than or equal to 2.

[0013] Preferably, the winding drum is a cylindrical structure, N is 2, and the sub-winding needle includes a first half winding needle and a second half winding needle arranged on the left and right.

[0014] Preferably, the diaphragm is coated with adhesive.

[0015] Preferably, a heating device is provided inside the sub-winding needle.

[0016] Preferably, the inner diameter of the reel is 2.1 mm to 10.1 mm, and the thickness of the sleeve is 0.02 mm to 1 mm.

[0017] Preferably, the outer surface of the sleeve has a pre-rolled layer formed by winding the diaphragm for several rounds, and the battery core strip is arranged on the outer side of the pre-rolled layer.

[0018] Preferably, the battery core strip includes a positive electrode strip and a negative electrode strip arranged in sequence.

[0019] Preferably, the inner side and the outer side of the sleeve are coated with polyvinylidene fluoride.

[0020] Preferably, the sleeve is made of polypropylene, aluminum alloy or magnesium alloy.

[0021] A battery cell product comprises an outer shell, wherein battery electrodes are arranged on both sides of the outer shell in an axial direction, and inside the outer shell are arranged:

[0022] N sleeves, the sleeves are connected to form a cylindrical reel, and the reel is arranged along the axial direction of the outer shell;

[0023] a diaphragm, wound around the outer surface of the sleeve along the circumference of the reel;

[0024] The battery strip is arranged between the interlayers of the separator;

[0025] Wherein N is a positive integer greater than or equal to 2.

[0026] The beneficial effects of the utility model: Due to the adoption of the above technical scheme, the utility model can effectively avoid the core pulling of the diaphragm when the winding needle is unwinding by setting the sleeve, and at the same time retaining the sleeve at the center hole position of the battery cell, which can stabilize the center structure and avoid the center hole collapse of the battery cell during subsequent cycles, affecting the electrochemical performance and safety performance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a battery cell winding process in the prior art;

[0028] Figure 2 This is a schematic diagram of the needle sleeve manufacturing process structure in the embodiment of the utility model;

[0029] Figure 3 This is a schematic diagram of the sleeve disassembly structure in the embodiment of the utility model;

[0030] Figure 4 This is a schematic diagram of the reel structure in which the value of N is 3 in the embodiment of the utility model;

[0031] Figure 5 A top view of a battery cell in an embodiment of the utility model;

[0032] Figure 6 It is a cross-sectional view of a battery cell product in an embodiment of the utility model.

[0033] In the attached drawings: 1, sub-winding needle; 11, first half winding needle; 12, second half winding needle; 2, diaphragm; 3, battery cell strip; 31, positive electrode strip; 32, negative electrode strip; 4, sleeve; 5, winding drum; 6, battery cell; 7, outer shell. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0035] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0036] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0037] A cylindrical battery core winding needle sleeve process structure, such as Figures 2 to 6 As shown, including,

[0038] N sub-winding needles 1;

[0039] A sleeve 4 corresponding to the shape of the sub-winding needle 1, a sleeve 4 is movably sleeved on the outer side of each sub-winding needle 1, and the sleeves 4 are connected to form a cylindrical winding drum 5;

[0040] The diaphragm 2 is wound around the outer surface of the sleeve 4 along the circumferential side of the winding drum 5;

[0041] The battery strip 3 is arranged between the layers of the separator 2;

[0042] Wherein N is a positive integer greater than or equal to 2.

[0043] Specifically, the utility model mainly targets the two problems mentioned in the background technology, namely, the core pulling of the winding needle and the collapse of the center hole of the battery cell. The utility model improves the existing winding equipment and adds a winding needle sleeve process structure to solve the above two technical problems at the same time. Before the battery strip 3 is wound, the utility model installs a sleeve 4 of matching size on each sub-winding needle 1 constituting the winding needle. The diaphragm 2 contacts the sleeve 4 during the winding process. After the winding of the battery cell is completed, the sub-winding needle 1 is separated from the sleeve 4, and the sleeve 4 is retained inside the center hole of the battery cell to support the inside of the battery cell 6. As described above, the sleeve 4 is installed on the sub-winding needle 1 before each winding begins. After the winding is completed, the sleeve 4 remains inside the battery cell 6, which can solve the problems of core pulling of the winding needle and the collapse of the center hole at the same time.

[0044] In a preferred embodiment, the winding needle is a cylindrical structure, N is 2, and the sub-winding needle 1 includes a first half winding needle 11 and a second half winding needle 12 arranged on the left and right.

[0045] Specifically, the utility model takes two sub-winding needles as an example, and the sub-winding needle 1 includes a first half winding needle 11 and a second half winding needle 12 arranged on the left and right respectively. Each sub-winding needle 1 is a semi-cylindrical structure, and then the rectangular surfaces are spliced ​​together to form a winding needle with a complete cylindrical structure. The utility model preferably adds a sleeve 4, and the sleeve 4 is pre-applied to the sub-winding needle 1 before winding. The subsequent process is as described above. After the winding is completed, the sub-winding needle 1 is removed from the sleeve 4, which avoids the winding needle core pulling. At the same time, the sleeve 4 remains in the center hole of the battery cell to support the center hole.

[0046] Of course, the value of N is 2 mainly to solve the problem of two sub-winding needles in the prior art. The number of N can be adjusted arbitrarily, and can be 3, 4, 5 or more, based on the requirements of the clamped diaphragm or other application needs. For example, when the value of N is 3, the winding drum structure is as follows Figure 4 shown.

[0047] In a preferred embodiment, the diaphragm 2 is coated with adhesive; preferably, the adhesive coating has a better bonding effect, avoids loosening of the diaphragm 2, and maintains the stability of the bonding between the diaphragm 2 and the sleeve.

[0048] In a preferred embodiment, a heating device is provided inside the sub-winding needle 1.

[0049] Specifically, the heating device can be a heating resistor. Preferably, the diaphragm can be better adhered to the outer side of the sleeve after being heated, and the diaphragm can be better prevented from loosening.

[0050] In a preferred embodiment, the inner diameter of the reel is 2.1 mm to 10.1 mm, and the thickness of the sleeve 4 is 0.02 mm to 1 mm.

[0051] Specifically, in the utility model, N sub-winding needles 1 can be connected with each other to form a cylindrical winding needle, and the diameter of the winding needle ranges from 2mm to 10mm. In order to make the sub-winding needle 1 easier to escape from the sleeve 4, the inner diameter of the sleeve 4 is slightly larger than the sub-winding needle 1. Therefore, the inner diameter of the winding drum is enlarged by 0.1mm compared with the diameter of the winding needle.

[0052] To be more specific, in the present invention, a winding needle can be formed by the mutual engagement of the sub-winding needles 1. The size of the winding needle in this embodiment is 2mm to 10mm according to the prior art. However, it should be noted that due to the provision of the sleeve 4, the sub-winding needles 1 of the present invention are not directly in contact with each other, that is, the sub-winding needles 1 are not directly engaged to form a columnar winding needle, but a winding drum 5 is formed based on the sleeve 4.

[0053] In a preferred embodiment, the outer surface of the sleeve 4 has a pre-rolled layer formed by winding the separator 2 for several times, and the battery core strip 3 is arranged on the outside of the pre-rolled layer.

[0054] Specifically, in the present invention, the separator 2 is pre-rolled along the winding drum 5 for 1-2 turns to form a pre-rolled layer to fix the position of the separator 2, and then the negative electrode strip 32 and the positive electrode strip 31 are rolled in sequence.

[0055] In a preferred embodiment, the battery cell strip 3 includes a positive electrode strip 31 and a negative electrode strip 32 which are arranged in sequence.

[0056] In a preferred embodiment, the inner and outer sides of the sleeve 4 are coated with polyvinylidene fluoride.

[0057] Preferably, the inner side and outer wall of the sleeve 4 are coated with polyvinylidene fluoride (PVDF), which can further fix the sleeve 4 and the inner diaphragm 2, make the tension of the diaphragm 2 easier to control during the winding process, and make the structure of the center hole more stable.

[0058] In a preferred embodiment, the sleeve 4 is made of polypropylene, aluminum alloy or magnesium alloy; specifically, it can also be a sleeve made of other light alloys.

[0059] A battery cell product, such as Figure 5 , as shown in 6, comprises an outer shell 7, battery electrodes are provided on both sides of the outer shell along the axial direction, and the outer shell 7 is provided with,

[0060] N sleeves 4, which are connected to form a cylindrical reel 5, and the reel 5 is arranged along the axial direction of the outer shell 7;

[0061] The diaphragm 2 is wound around the outer surface of the sleeve 4 along the circumferential side of the winding drum 5;

[0062] The battery strip 3 is arranged between the layers of the separator 2;

[0063] Wherein N is a positive integer greater than or equal to 2.

[0064] Specifically, the battery cell product of the utility model retains the cell structure of the sleeve 4 after the winding needle is pulled out. By setting the sleeve 4, the diaphragm core pulling when the winding needle is unwinding can be effectively avoided. At the same time, the sleeve structure is introduced at the center hole position of the battery cell 6, which can stabilize the center structure and avoid the center hole collapse of the battery cell 6 during subsequent cycles, which affects the electrochemical performance and safety performance of the battery cell.

[0065] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A winding needle sleeve process structure for cylindrical battery cells, characterized in that: include, N sub-winding needles (1); A sleeve (4) having a shape corresponding to the sub-winding needle (1), wherein the outer side of each sub-winding needle (1) is movably sleeved with the sleeve (4), and the sleeves (4) are connected to form a columnar winding drum (5); A diaphragm (2) is wound around the outer surface of the sleeve (4) along the circumference of the reel (5); A battery core strip (3) is arranged between the interlayers of the separator (2); Wherein N is a positive integer greater than or equal to 2.

2. The cylindrical battery core winding needle sleeve manufacturing process structure according to claim 1, characterized in that: The winding drum (5) is a cylindrical structure, N is 2, and the sub-winding needle (1) comprises a first half winding needle (11) and a second half winding needle (12) arranged on the left and right.

3. The cylindrical battery core winding needle sleeve process structure according to claim 1, characterized in that: The diaphragm (2) is coated with adhesive.

4. The cylindrical battery core winding needle sleeve manufacturing process structure according to claim 1, characterized in that: The sub-winding needle (1) is provided with a heating device.

5. The winding needle sleeve process structure for cylindrical battery cells according to claim 1, characterized in that: The inner diameter of the reel (5) is 2.1 mm to 10.1 mm, and the thickness of the sleeve (4) is 0.02 mm to 1 mm.

6. The cylindrical battery core winding needle sleeve manufacturing process structure according to claim 1, characterized in that: The outer surface of the sleeve (4) has a pre-rolled layer formed by winding the diaphragm (2) for several turns, and the battery core strip (3) is arranged on the outside of the pre-rolled layer.

7. The cylindrical battery core winding needle sleeve manufacturing process structure according to claim 1, characterized in that: The battery core strip (3) comprises a positive electrode strip (31) and a negative electrode strip (32) which are arranged in sequence.

8. The cylindrical battery core winding needle sleeve manufacturing process structure according to claim 1, characterized in that: The inner side and the outer side of the sleeve (4) are coated with polyvinylidene fluoride.

9. The cylindrical battery core winding needle sleeve manufacturing process structure according to claim 1, characterized in that: The sleeve (4) is made of polypropylene, aluminum alloy or magnesium alloy.

10. A battery cell product, comprising an outer shell (7), wherein the outer shell (7) is provided with battery electrodes on both sides along the axial direction, characterized in that: The outer shell (7) is provided with: N sleeves (4), the sleeves (4) being connected to form a columnar reel (5), the reel (5) being arranged along the axial direction of the outer shell (7); A diaphragm (2) is wound around the outer surface of the sleeve (4) along the circumference of the reel (5); A battery core strip (3) is arranged between the interlayers of the separator (2); Wherein N is a positive integer greater than or equal to 2.

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