Pole piece capable of preventing foil from being cut and wound battery cell having the same

Abstract

The utility model discloses a pole piece with a function of preventing foil from being cut, comprising a pole piece body, a pole ear for welding with the pole piece body, and an anti-cutting protection structure. The pole ear is horizontally placed on the pole piece body in a stacked manner along the width direction of the pole piece body, the first end of the pole ear is biased inward relative to the pole piece body, and the second end opposite to the pole ear extends out of the pole piece body. The anti-cutting protection structure is arranged on the pole piece body and / or the first end of the pole ear, and the anti-cutting protection structure on the first end of the pole ear also surrounds the first end. The pole piece with a function of preventing foil from being cut of the utility model can prevent the risk of burrs on the first end of the pole ear piercing the diaphragm and / or the foil in the pole piece body during the winding process. In addition, the utility model also discloses a wound battery cell.

Description

Technical Field

[0001] The utility model relates to a secondary battery (such as but not limited to a lithium battery), and in particular to a pole piece with a foil-breaking prevention function in the secondary battery and a wound battery core with the pole piece. Background Art

[0002] With the vigorous development of the new energy industry, a huge market is provided for the battery industry, thereby accelerating the pace of development of the battery industry.

[0003] At present, lithium-ion cylindrical batteries have gradually become the mainstream products in the new energy industry due to their advantages such as high energy density, high charge and discharge rate, and good capacity consistency. Among them, the use of tab structure is also the structural direction of cylindrical batteries determined by traditional manufacturers. Its common problems are as follows:

[0004] As battery performance improves, the thickness of foil gradually decreases. When using tabs as the positive and negative lead-out terminals of the battery cell, the burrs in the cutting of the tabs pose a risk of piercing the foil or diaphragm during winding, thus causing battery safety problems.

[0005] At the same time, during high-rate discharge or long cycles of the battery, due to the expansion and contraction of the negative electrode, the tab can easily cause the foil to break and cause a short circuit when it is exposed.

[0006] Therefore, there is an urgent need for a pole piece with a foil-preventing function and a wound battery cell with the pole piece to overcome the above-mentioned defects. Utility Model Content

[0007] One object of the utility model is to provide a pole piece with the function of preventing foil from being cut, so as to prevent the risk of burrs piercing the foil in the diaphragm and / or the pole piece body.

[0008] Another object of the utility model is to provide a wound battery core that can prevent the risk of burrs piercing the diaphragm and / or the foil in the pole piece body.

[0009] To achieve the above-mentioned purpose, the pole piece with the function of preventing foil from being cut in the utility model comprises a pole piece body, a pole ear and an anti-cutting protection structure. The pole ear is used for welding with the pole piece body, and the pole ear is placed horizontally on the pole piece body in a stacked manner along the width direction of the pole piece body, and the first end of the pole ear is biased inward relative to the pole piece body, and the second end opposite to the pole ear extends out of the pole piece body. The anti-cutting protection structure is provided on the pole piece body and / or the first end of the pole ear, and the anti-cutting protection structure on the first end of the pole ear also surrounds the first end.

[0010] Compared with the prior art, by means of the design that "the anti-cutting protection structure is arranged on the first end of the pole piece body and / or the pole ear, and the anti-cutting protection structure on the first end of the pole ear also surrounds the first end", the burrs at the cross section of the first end of the pole ear are wrapped up, so that the burrs can be prevented from piercing the diaphragm and / or the foil in the pole piece body during the winding process and / or the high-rate discharge or long cycle of the battery, thereby ensuring the safety of the battery with the pole piece of the utility model.

[0011] Preferably, the anti-cutting protection structure on the first end of the pole ear is a high-temperature adhesive tape, and the anti-cutting protection structure on the pole piece body is a high-temperature adhesive layer or a high-temperature adhesive tape.

[0012] Preferably, the anti-cutting protection structure of the pole piece body protrudes from the anti-cutting protection structure on the first end of the pole ear in the length direction and the width direction of the pole piece body.

[0013] Preferably, the anti-fracture protection structure on the first end of the pole ear protrudes from the first end along the width direction of the pole piece body.

[0014] Preferably, the anti-splitting protection structure on the first end of the pole ear is open from head to tail in the circumferential direction, and the open portion is arranged opposite to the pole piece body.

[0015] Preferably, the pole piece body has a welding area located between the anti-fracture protection structure and the second end of the pole lug along the width direction of the pole piece body, and the pole lug is welded to the welding area.

[0016] Preferably, the tab is ultrasonically welded to the welding area.

[0017] Preferably, the pole lug has a bending structure located between its first end and second end, which is bent in a direction away from the pole piece body, and the bending structure makes the first end of the pole lug staggered with the second end of the pole lug in the thickness direction of the pole piece body.

[0018] Preferably, the bending structure is arranged adjacent to the anti-cutting protection structure.

[0019] To achieve the above purpose, the wound battery cell of the utility model comprises a rolled positive electrode sheet, a rolled negative electrode sheet and a rolled separator separating the positive electrode sheet and the negative electrode sheet. At least one of the positive electrode sheet and the negative electrode sheet is the aforementioned electrode sheet with the function of preventing the foil from being cut.

[0020] Compared with the prior art, by means of the design that "the anti-cutting protection structure is arranged on the first end of the pole piece body and / or the pole ear, and the anti-cutting protection structure on the first end of the pole ear also surrounds the first end", the burrs at the cross section of the first end of the pole ear are wrapped up, so that the burrs can be prevented from piercing the diaphragm and / or the foil in the pole piece body during the winding process and / or the high-rate discharge or long cycle of the battery, thereby ensuring the safety of the battery with the wound battery cell of the utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The utility model is a plan view of a wound battery cell having a pole piece for preventing foil from being cut.

[0022] Figure 2 It is a three-dimensional diagram of the pole piece of the utility model which has the function of preventing the foil from being cut when it is not wound, and the three-dimensional diagram only shows a part of the pole piece body.

[0023] Figure 3 yes Figure 2 Plan view along the direction indicated by arrow B.

[0024] Figure 4 yes Figure 2 A plan view viewed from the direction opposite to that indicated by arrow C. DETAILED DESCRIPTION

[0025] Embodiments of the present invention will now be described with reference to the accompanying drawings, in which like reference numerals represent like elements.

[0026] See also Figure 2 The utility model has a pole piece 10 for preventing the foil from being cut and is applied to Figure 1 In the wound battery cell 100 shown in FIG. 1 , burrs in the wound battery cell 100 are prevented from piercing the separator 40 (see FIG. Figure 1 ) and the foil risk in the pole piece body 11. In addition, although Figure 1 The wound battery cell 100 shown is circular, but it can be square or other shapes according to actual needs. Figure 1 Limits shown.

[0027] Recombination Figure 3 and Figure 4The utility model has a pole piece 10 for preventing foil from being cut, which comprises a pole piece body 11 , a pole ear 12 and an anti-cutting protection structure 13 . The pole ear 12 is used for welding with the pole piece body 11 to meet the need of electrically connecting the pole piece body 11 with external components (such as a cover plate, a battery casing, etc.) by means of the pole ear 12; the pole ear 12 is horizontally placed on the pole piece body 11 in a stacked manner along the width direction of the pole piece body 11, that is, the pole ear 12 is horizontally placed on the pole piece body 11 along the width direction of the pole piece body 11, and the pole ear 12 horizontally placed on the pole piece body 11 is also stacked with the pole body 11, so that the stacking direction of both the pole ear 12 and the pole piece body 11 is parallel to the thickness direction of the pole piece body 11; the first end 121 of the pole ear 12 is biased inwardly relative to the pole piece body 11 to meet the need that the first end 121 of the pole ear 12 does not extend out of the pole piece body 11 in the width direction of the pole piece body 11 (see the direction indicated by arrow A and the opposite direction); the second end 121 opposite to the pole ear 12 extends out of the pole piece body 11, and the state is shown in FIG. Figures 2 to 4 shown.

[0028] At the same time, the anti-splitting protection structure 13 is provided on the first end 121 of the pole piece body 11 and the pole ear 12, that is, the pole piece body 11 and the first end 121 of the pole ear 12 are each provided with an anti-splitting protection structure 13, and the anti-splitting protection structure 13 on the first end 121 of the pole ear 12 also surrounds the first end 121; so as to more effectively prevent the burrs at the cross section of the first end 121 of the pole ear 12 from piercing the diaphragm 40 during the winding process of the pole piece 10 of the utility model (see Figure 1 ) and / or the risk of foil in the pole piece body 11. It should be noted that, since the pole ear 12 is obtained by cutting the free end of the unwound pole ear roll, there are burrs at the cross section of the end of the pole ear 12. Therefore, in other embodiments, the anti-splitting protection structure 13 can also be only provided on the pole piece body 11 or the first end 121 of the pole ear 12. As long as the anti-splitting protection structure 13 provided on the pole piece body 11 or the first end 121 of the pole ear 12 covers the first end 121 of the pole ear 12 during the winding process, it is not necessary to Figures 2 to 4 More specifically, as follows:

[0029] like Figure 2 and Figure 4 As shown, as an example, the anti-splitting protection structure 13 of the pole piece body 11 protrudes from the anti-splitting protection structure 13 on the first end 121 of the pole ear 12 in the length direction (see the direction indicated by arrow B and the opposite direction) and the width direction (see the direction indicated by arrow A and the opposite direction) of the pole piece body 11, so as to form at least one circle of surrounding surrounding layer during the winding process of the pole piece 10 of the utility model, thereby maximally preventing the burrs on the first end 121 of the pole ear 12 from piercing the diaphragm 40 (see Figure 1) and / or the foil risk in the pole piece body 11. Figure 2 and Figure 4 As an example, the anti-splitting protection structure 13 on the first end 121 of the pole lug 12 protrudes from the first end 121 along the width direction of the pole piece body 11 to better cover the burrs at the cross section of the first end 121 of the pole lug 12. Figure 2 and Figure 4 As shown, as an example, the anti-splitting protection structure 13 on the first end 121 of the pole lug 12 is open at the head and tail in the circumferential direction, and the open part 131 is arranged opposite to the pole piece body 11, so as to facilitate the circumferential bonding operation of the anti-splitting protection structure 13 on the first end 121 of the pole lug 12. For example, as an example, the anti-splitting protection structure 13 on the first end 121 of the pole lug 12 is a high-temperature adhesive tape, so that the anti-splitting protection structure 13 can be operated around the first end 121; the anti-splitting protection structure 13 on the pole piece body 11 is a high-temperature adhesive layer, so that the anti-splitting protection structure 13 on the pole piece body 11 and the anti-splitting protection structure 13 on the first end 121 of the pole lug 12 are bonded and fixed; obviously, according to actual needs, the anti-splitting protection structure 13 on the pole piece body 11 can also be a high-temperature adhesive tape.

[0030] like Figures 2 to 4 As an example, the pole piece body 11 has a welding area located between the anti-splitting protection structure 13 and the second end 122 of the pole ear 12 along the width direction of the pole piece body 11, see Figure 4 The dotted square indicated by the middle number 111 is where the pole ear 12 is welded to the welding area 111; optionally, as an example, the pole ear 12 is ultrasonically welded to the welding area 111 to ensure the stability of the welding between the pole ear 12 and the pole piece body 11. Figures 2 to 4 As an example, the pole ear 12 has a bending structure 123 bent in a direction away from the pole piece body 11 at a position between the first end 121 and the second end 122. Optionally, Figure 2 and Figure 4In the figure, as an example, the bending structure 123 is arranged adjacent to the anti-cut protection structure 13, and the bending structure 123 makes the first end 121 of the pole lug 12 staggered with the second end 121 of the pole lug 12 in the thickness direction of the pole piece body 10; such a design can ensure that the pole lug 12 is closely connected with the welding area 111 of the pole piece body 11 (for example, face to face), and can ensure that the anti-cut protection structure 13 on the pole piece body 11 is closely connected with the anti-cut protection structure 13 on the first end 121 of the pole lug 12, thereby effectively preventing the close connection between the pole lug 12 and the welding area 111 from being affected by the anti-cut protection structure 13 on the first end 121 of the pole lug 12 and the pole piece body 11. It should be noted that the dotted square indicated by the reference numeral 111 is only one type of welding area. Of course, the shape and size of the welding area can also be other, so it is not used as an example. Figure 4 Limits shown.

[0031] See also Figure 1 The wound battery cell 100 of the present invention includes a rolled positive electrode sheet 20, a rolled negative electrode sheet 30, and a rolled separator 40 separating the positive electrode sheet 20 from the negative electrode sheet 30. The positive electrode sheet 20 and the negative electrode sheet 30 are both the aforementioned electrode sheets 10 with the function of preventing the foil from being cut; of course, according to actual needs, the positive electrode sheet 20 or the negative electrode sheet 30 can also be the aforementioned electrode sheet 10 with the function of preventing the foil from being cut.

[0032] Compared with the prior art, the anti-splitting protection structure 13 is provided on the first end 121 of the pole piece body 11 and / or the pole ear 12, and the anti-splitting protection structure 13 on the first end 121 of the pole ear 12 also surrounds the first end 121, so that the burrs at the cross section of the first end 121 of the pole ear 12 are wrapped up, so that the burrs are prevented from piercing the diaphragm 40 and / or the foil in the pole piece body 11 during the winding process and / or the high-rate discharge or long cycle of the battery, thereby ensuring the safety of the battery with the pole piece 10 of the utility model. Similarly, the wound battery cell 100 with the pole piece 10 also has the aforementioned effect.

[0033] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A pole piece with a function of preventing foil from being cut, comprising a pole piece body and a pole ear for welding with the pole piece body, wherein the pole ear is stacked and horizontally arranged on the pole piece body along the width direction of the pole piece body, the first end of the pole ear is biased inward relative to the pole piece body, and the second end of the pole ear is extended out of the pole piece body, characterized in that: The pole piece with the function of preventing foil from being cut also includes an anti-cutting protection structure, which is arranged on the pole piece body and / or the first end of the pole ear. The anti-cutting protection structure on the first end of the pole ear also surrounds the first end.

2. The pole piece with the function of preventing foil from being cut according to claim 1, characterized in that: The anti-cutting protection structure on the first end of the pole ear is a high-temperature adhesive tape, and the anti-cutting protection structure on the pole piece body is a high-temperature adhesive layer or a high-temperature adhesive tape.

3. The pole piece with the function of preventing foil from being cut according to claim 1, characterized in that: The anti-crack protection structure of the pole piece body protrudes from the anti-crack protection structure on the first end of the pole ear in the length direction and the width direction of the pole piece body.

4. The pole piece with the function of preventing foil from being cut according to claim 1, characterized in that: The anti-splitting protection structure on the first end of the pole ear protrudes from the first end along the width direction of the pole piece body.

5. The pole piece with the function of preventing foil from being cut according to claim 4, characterized in that: The anti-splitting protection structure on the first end of the pole ear is open from beginning to end in the circumferential direction, and the open portion is arranged opposite to the pole piece body.

6. The pole piece with the function of preventing foil from being cut according to claim 1, characterized in that: The pole piece body has a welding area located between the anti-fracture protection structure and the second end of the pole lug along the width direction of the pole piece body, and the pole lug is welded to the welding area.

7. The pole piece with the function of preventing foil from being cut according to claim 6, characterized in that: The pole tab is ultrasonically welded to the welding area.

8. The pole piece with the function of preventing foil from being cut according to claim 1, characterized in that: The pole lug has a bending structure located between the first end and the second end thereof, which is bent in a direction away from the pole piece body. The bending structure causes the first end of the pole lug to be offset from the second end of the pole lug in the thickness direction of the pole piece body.

9. The pole piece with the function of preventing foil from being cut according to claim 8, characterized in that: The bending structure is arranged adjacent to the anti-splitting protection structure.

10. A wound battery cell, comprising a rolled positive electrode sheet, a rolled negative electrode sheet and a rolled separator separating the positive electrode sheet from the negative electrode sheet, characterized in that: At least one of the positive electrode sheet and the negative electrode sheet is the electrode sheet with the function of preventing foil from being cut according to any one of claims 1 to 9.

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