Cell, battery, and battery pack

Abstract

The present disclosure discloses a cell (10), a battery (100), and a battery pack. The battery core (10) includes: at least one core (20), where each core (20) has a plurality of tabs (201), the plurality of tabs (201) successively form, after being converged, a tab end-portion staggered layer region (203), a tab soldering region (204), and a pre-soldered press-fit region (205), parts of the plurality of tabs (201) exposed out of the core (20) form a tab exposure region (206), and a length of the tab (201) exposed out of the core (20) in the tab exposure region (206) is determined according to a width of the tab end-portion staggered layer region (203), a width of the tab soldering region (204), a width of the pre-soldered press-fit region (205), a thickness of the core (20), and a tab bending angle of the tab (201).

Description

CELL, BATTERY, AND BATTERY PACK CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present disclosure claims priority to and benefits of Chinese Patent Application No. 202010898785.4, entitled "CELL, BATTERY, AND BATTERY PACK" and filed by BYD Co., Ltd. on August 31, 2020. FIELD

[0002] The present disclosure relates to the field of batteries, and particularly, to a cell, a battery, and a battery pack. BACKGROUND

[0003] In the related art, a plurality of tabs of a core are soldered together after being converged, and parts of the plurality of tabs exposed out of the core form a tab exposure region. If the length of the tab exposure region is designed too long, the movable length of the tab is increased, and a larger bending space is required for accommodating the tab. The design of a larger bending space leads to a capacity loss of the cell. If the bending space is not increased, the tab is compressed, which is likely to cause positive and negative electrodes to come into contact with each other, posing a safety risk.

[0004] If the length of the tab exposure region is designed too short, the tab after bending is likely to be pulled to cause tearing of the tab. Once the tab is torn, some electrode plates cannot output electricity, resulting in a capacity loss of the cell. SUMMARY

[0005] The present disclosure aims to resolve at least one of the technical problems existing in the prior art. In view of this, the present disclosure provides a cell. The cell can prevent a tab from being pulled after bending, can avoid a capacity loss of the cell, and can also prevent the tab from being compressed, so as to improve the safety of the battery in use.

[0006] The present disclosure further provides a battery.

[0007] The present disclosure further provides a battery pack.

[0008] The cell according to the present disclosure includes: at least one core, where each core has a plurality of tabs, the plurality of tabs successively form, after being converged, a tab end-portion staggered layer region, a tab soldering region, and a pre-soldered press-fit region, parts of the plurality of tabs exposed out of the core form a tab exposure region, and a length of the tab exposed out of the core in the tab exposure region is determined according to a width of the tab end-portion staggered layer region, a width of the tab soldering region, a width of the pre- soldered press-fit region, a thickness of the core, and a tab bending angle of the tab.

[0009] According to the cell in the present disclosure, the length of the tab exposed out of the core in the tab exposure region can be made more appropriate, and the tab after bending can be prevented from being pulled and torn, and therefore, the capacity loss of the cell can be avoided. Moreover, the movable length of the tab can also be made appropriate, and the bending space can be made appropriate, and therefore, the capacity loss of the cell can be avoided. In addition, the tab can be prevented from being compressed, so as to improve the safety of the cell in use.

[0010] According to some embodiments of the present disclosure, the width of the tab end-portion staggered layer region is <com:Math><semantics>d1<annotation encoding="application / x-tex">d_1< / annotation>< / semantics>< / com:Math>, the tab soldering region is provided with a tab protection sheet, a width of the tab protection sheet is <com:Math><semantics>d2<annotation encoding="application / x-tex">d_2< / annotation>< / semantics>< / com:Math>, the width of the pre-soldered press-fit region is <com:Math><semantics>d3<annotation encoding="application / x-tex">d_3< / annotation>< / semantics>< / com:Math>, the thickness of the core is D, and the tab bending angle of any one tab in the plurality of tabs is A, the length of the exposed tab in the tab exposure region is L, and a relational expression <com:Math><semantics>L=d1+d2+d3+D / 2*tanA<annotation encoding="application / x-tex">L=d_1+d_2+d_3+D / 2*tan A< / annotation>< / semantics>< / com:Math> is satisfied.

[0011] According to some embodiments of the present disclosure, A satisfies a relational expression 45° \( \leq A \leq 135° \).

[0012] According to some embodiments of the present disclosure, a ratio of <com:Math><semantics>d2<annotation encoding="application / x-tex">d_2< / annotation>< / semantics>< / com:Math> to <com:Math><semantics>d1<annotation encoding="application / x-tex">d_1< / annotation>< / semantics>< / com:Math> is B, and satisfies a relational expression <com:Math><semantics>4<B<10<annotation encoding="application / x-tex">4 < B < 10< / annotation>< / semantics>< / com:Math>.

[0013] According to some embodiments of the present disclosure, a ratio of <com:Math><semantics>d2<annotation encoding="application / x-tex">d_2< / annotation>< / semantics>< / com:Math> to <com:Math><semantics>d3<annotation encoding="application / x-tex">d_3< / annotation>< / semantics>< / com:Math> is C, and satisfies a relational expression <com:Math><semantics>4<C<24<annotation encoding="application / x-tex">4 < C < 24< / annotation>< / semantics>< / com:Math>.

[0014] According to some embodiments of the present disclosure, a relational expression 0 mm<com:Math><semantics><<annotation encoding="application / x-tex"><< / annotation>< / semantics>< / com:Math> d<com:Sub>1< / com:Sub><com:Math><semantics><<annotation encoding="application / x-tex"><< / annotation>< / semantics>< / com:Math>8 mm is satisfied.

[0015] According to some embodiments of the present disclosure, a relational expression 8 mm <com:Math><semantics>≤<annotation encoding="application / x-tex">\leq< / annotation>< / semantics>< / com:Math> d<com:Sub>2< / com:Sub> <com:Math><semantics>≤<annotation encoding="application / x-tex">\leq< / annotation>< / semantics>< / com:Math> 12 mm is satisfied.

[0016] According to some embodiments of the present disclosure, a relational expression 0.5 mm <com:Math><semantics>≤<annotation encoding="application / x-tex">\leq< / annotation>< / semantics>< / com:Math> d<com:Sub>3< / com:Sub><com:Math><semantics>≤<annotation encoding="application / x-tex">\leq< / annotation>< / semantics>< / com:Math> 2 mm is satisfied.

[0017] The battery according to the present disclosure includes the cell.

[0018] The battery pack according to the present disclosure includes the battery.

[0019] The additional aspects and advantages of the present disclosure will be set forth in part in the description below, parts of which will become apparent from the description below, or will be understood by the practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a schematic diagram of a battery according to an embodiment of the present disclosure;

[0021] FIG. 2 is a schematic diagram in which tabs of a core of a cell have not been bent after being converged according to an embodiment of the present disclosure; and

[0022] FIG. 3 is another schematic diagram in which tabs of a core of a cell have not been bent after being converged according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] A detail description of the embodiments of the present disclosure will be made in the following, and examples thereof are illustrated in the accompanying drawings, throughout which identical or similar elements or elements having identical or similar functions are represented with identical or similar reference numerals. The embodiments that are described with reference to the accompanying drawings are exemplary, and are only used to interpret the present disclosure, instead limiting the present disclosure.

[0024] A cell 10 according to the embodiments of the present disclosure is described below with reference to FIG. 1 to FIG. 3.

[0025] As shown in FIG. 1 to FIG. 3, the cell 10 according to the embodiments of the present disclosure includes: at least one core 20, where each core 20 has a plurality of tabs 201, the plurality of tabs 201 successively form, after being converged, a tab end-portion staggered layer region 203, a tab soldering region 204, and a pre-soldered press-fit region 205. It is to be noted that free ends of the plurality of tabs 201 jointly form the tab end-portion staggered layer region 203, because curved radians of the tabs 201 are different after the plurality of tabs 201 are converged. The pre-soldered press-fit region 205 is a region formed by press-fitting the plurality of tabs 201, which have been converged, at the position of convergence by ultrasonic soldering or other soldering methods. The tab soldering region 204 is a region formed by soldering the tabs 201 and a tab lead-out sheet in a laser soldering or another soldering manner in the pre-soldered press- fit region 205. The parts of the plurality of tabs 201 exposed out of the core 20 form the tab exposure region 206. In an extension direction of the tab 201, that is, a left-right direction shown in FIG. 2, a length of the tab exposed out of the core 10 in the tab exposure region 206 is determined according to a width of the tab end-portion staggered layer region 203, a width of the tab soldering region 204, a width of the pre-soldered press-fit region 205, a thickness of the core 20, and a tab bending angle of the tab 201.

[0026] According to some embodiments of the present disclosure, a width direction of the tab end-portion staggered layer region 203, a width direction of the tab soldering region 204, and a width direction of the pre-soldered press-fit region 205 are all the left-right direction shown in FIG. 2. A thickness direction of the core 20 is an up-down direction shown in FIG. 2, and when the tabs 201 of the core 20 have not been bent after being converged, the exposed tab extends in the left-right direction shown in FIG. 2. Each core 20 has a plurality of separators 202, and parts of the plurality of tabs 201 exposed out of the separators 202 form the tab exposure region 206.

[0027] By determining the length of the tab exposure region 206 according to the width of the tab end-portion staggered layer region 203, the width of the tab soldering region 204, the width of the pre-soldered press-fit region 205, the thickness of the core 20, and the tab bending angle of the tab 201, the length of the tab in the tab exposure region 206 exposed out of the core 20 can be made more appropriate, so as to prevent the tab 201 from being pulled and torn after bending, and avoid the problem that some electrode plates cannot output electricity, thereby avoiding a capacity loss of the cell 10. In addition, the movable length of the tab 201 can also be made appropriate, and the bending space for accommodating the tabs 201 can be made appropriate, so as to avoid the capacity loss of the cell 10, and prevent the tabs 201 from being compressed to cause positive and negative electrodes of the cell 10 to come into contact with each other and cause a short circuit of the cell 10, thereby improving the safety of the cell 10 in use.

[0028] In some embodiments of the present disclosure, as shown in FIG. 2, the width of the tab end-portion staggered layer region 203 is <com:Math><semantics>d1<annotation encoding="application / x-tex">d_1< / annotation>< / semantics>< / com:Math>, the tab soldering region 204 is provided with a tab protection sheet 207, a width of the tab protection sheet 207 is <com:Math><semantics>d2<annotation encoding="application / x-tex">d_2< / annotation>< / semantics>< / com:Math>, a width direction of the tab protection sheet 207 is the left-right direction shown in FIG. 2, the width of the pre-soldered press- fit region 205 is d₃, the thickness of the core 20 is D, the tab bending angle of any one tab 201 in the plurality of tabs 201 is A, the length of the exposed tab in the tab exposure region 206 is L, and a relational expression <com:Math><semantics>L=d1+d2+d3+D / 2*tanA<annotation encoding="application / x-tex">L=d_1+d_2+d_3+D / 2*tan A< / annotation>< / semantics>< / com:Math> is satisfied. Such a setting can ensure that the length of the tab exposed out of the core 20 in the tab exposure region 206 is more appropriate, can further prevent the tabs 201 from being pulled after bending, further prevent the tabs 201 from being torn, and avoid the problem that some electrode plates cannot output electricity, thereby further avoiding the capacity loss of the cell 10. In addition, the movable length of the tab 201 can be ensured to be more appropriate, and the bending space for accommodating the tabs 201 can be made more appropriate, so as to avoid the capacity loss of the cell 10, and further prevent the tabs 201 from being compressed to cause positive and negative electrodes of the cell 10 to come into contact with each other, so as to better prevent a short circuit of the cell 10, thereby further improving the safety of the battery 100 in use.

[0029] According to some embodiments of the present disclosure, A satisfies a relational expression <com:Math><semantics>45∘≤A≤135∘<annotation encoding="application / x-tex">45^{\circ} \le A \le 135^{\circ}< / annotation>< / semantics>< / com:Math>, and preferably, <com:Math><semantics>60∘≤A≤120∘<annotation encoding="application / x-tex">60^{\circ} \le A \le 120^{\circ}< / annotation>< / semantics>< / com:Math>. Such a setting makes the bending angle of the tab 201 more appropriate, can make the length of the tab exposed out of the core 20 in the tab exposure region 206 appropriate, and prevent the separator 202 from being compressed to cause the positive and negative electrode of the cell 10 to come into contact with each other, so as to better prevent a short circuit of the cell 10.

[0030] In some embodiments of the present disclosure, a ratio of <com:Math><semantics>d2<annotation encoding="application / x-tex">d_2< / annotation>< / semantics>< / com:Math> to <com:Math><semantics>d1<annotation encoding="application / x-tex">d_1< / annotation>< / semantics>< / com:Math> is B, and satisfies a relational expression <com:Math><semantics>4<B<10<annotation encoding="application / x-tex">4 < B < 10< / annotation>< / semantics>< / com:Math>. Further, a ratio of <com:Math><semantics>d2<annotation encoding="application / x-tex">d_2< / annotation>< / semantics>< / com:Math> to <com:Math><semantics>d3<annotation encoding="application / x-tex">d_3< / annotation>< / semantics>< / com:Math> is C, and satisfies a relational expression <com:Math><semantics>4<C<24<annotation encoding="application / x-tex">4 < C < 24< / annotation>< / semantics>< / com:Math>. Such a setting makes the ratio of <com:Math><semantics>d2<annotation encoding="application / x-tex">d_2< / annotation>< / semantics>< / com:Math> to <com:Math><semantics>d1<annotation encoding="application / x-tex">d_1< / annotation>< / semantics>< / com:Math> and the ratio of <com:Math><semantics>d2<annotation encoding="application / x-tex">d_2< / annotation>< / semantics>< / com:Math> to <com:Math><semantics>d3<annotation encoding="application / x-tex">d_3< / annotation>< / semantics>< / com:Math> appropriate, which facilitates the production and manufacture of the core 20. In addition, the soldering width of the tab soldering region 204 can be made appropriate, so as to ensure that the plurality of tabs 201 can be soldered together reliably, thereby improving the reliability of the cell 10 in use.

[0031] In some embodiments of the present disclosure, a relational expression 0 mm<com:Math><semantics><<annotation encoding="application / x-tex"><< / annotation>< / semantics>< / com:Math>d<com:Sub>1< / com:Sub><com:Math><semantics><<annotation encoding="application / x-tex"><< / annotation>< / semantics>< / com:Math>8 mm is satisfied. Preferably, d<com:Sub>1< / com:Sub> is 4 mm. Such a setting makes the width of the tab end- portion staggered layer region 203 appropriate, which can prevent the width of the tab end-portion staggered layer region 203 from being too large, so as to make the length of the tab exposure region 206 more appropriate.

[0032] In some embodiments of the present disclosure, a relational expression 8 mm<com:Math><semantics>≤<annotation encoding="application / x-tex">\leq< / annotation>< / semantics>< / com:Math>d<com:Sub>2< / com:Sub><com:Math><semantics>≤<annotation encoding="application / x-tex">\leq< / annotation>< / semantics>< / com:Math>12 mm is satisfied. Preferably, d<com:Sub>2< / com:Sub> is 10 mm. Such a setting makes the width of the tab protection sheet 207 appropriate, and the soldering width of the tab soldering region 204 can be ensured, so as to make the length of the tab exposure region 206 appropriate, thereby further facilitating the production and manufacture of the core 20.

[0033] In some embodiments of the present disclosure, a relational expression 0.5 mm<com:Math><semantics>≤<annotation encoding="application / x-tex">\leq< / annotation>< / semantics>< / com:Math>d<com:Sub>3< / com:Sub><com:Math><semantics>≤<annotation encoding="application / x-tex">\leq< / annotation>< / semantics>< / com:Math>2 mm is satisfied. Preferably, d<com:Sub>3< / com:Sub> is 1.5 mm. When soldering the plurality of tabs 201, setting d<com:Sub>3< / com:Sub> to 1.5 mm can make the width of the pre-soldered press-fit region 205 appropriate, so that a pre-soldering and pressing block can firmly press the plurality of tabs 201, so as to ensure the soldering quality of the plurality of tabs 201, thereby ensuring the production quality of the cell 10.

[0034] A battery 100 according to the embodiments of the present disclosure includes the cell 10 in the foregoing embodiments, and the cell 10 is disposed on the battery 100. Therefore, the length of the tab exposed out of the core 20 in the tab exposure region 206 can be made more appropriate, and the tab 201 after bending can be prevented from being pulled and torn, so as to avoid a capacity loss of the cell 10 and further to avoid the capacity loss of the battery 100. Moreover, the movable length of the tab 201 can be made appropriate, the bending space can be made appropriate, and therefore, the capacity loss of the cell 10 can be avoided. In addition, the tab 201 can be prevented from being compressed, so as to improve the safety of the cell 10 in use, and further to improve the safety of the battery 100 in use.

[0035] A battery pack according to the embodiments of the present disclosure includes the battery 100 in the foregoing embodiments. The battery 100 is disposed in the battery pack, which can avoid the capacity loss of the battery pack and improve the safety of the battery pack in use.

[0036] In the description of this specification, the description of the reference terms such as "an embodiment", "some embodiments", "exemplary embodiments", "example", "specific example", or "some examples" means that specific features, structures, materials or characteristics described with reference to the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, exemplary descriptions of the foregoing terms do not necessarily refer to the same embodiment or example. In addition, the described specific features, structures, materials, or characteristics may be combined in a proper manner in any one or more of the embodiments or examples.

[0037] Although the embodiments of the present disclosure are already shown and described above, a person of ordinary skill in the art is to be understood that various changes, modifications, replacements, and variations may be made to the embodiments without departing from the principles and spirit of the present disclosure, and the scope of the present disclosure is defined by the appended claims and their equivalents.

Claims

1. A cell, comprising: at least one core, wherein each core has a plurality of tabs, the plurality of tabs successively form, after being converged, a tab end-portion staggered layer region, a tab soldering region, and a pre-soldered press-fit region, parts of the plurality of tabs exposed out of the at least one core form a tab exposure region, wherein the tab end-portion staggered layer region is jointly formed by free ends of the plurality of tabs, the tab soldering region is a region formed by soldering the plurality of tabs, and the pre-soldered press-fit region is a region formed by press-fitting the plurality of tabs, wherein a length of a tab exposed out of the at least one core in the tab exposure region, a width of the tab end-portion staggered layer region, a width of the tab soldering region, and a width of the pre-soldered press-fit region are all in a first direction that is an extension direction of the tab, wherein a thickness of the at least one core is in a second direction, and wherein the length of the tab exposed out of the at least one core in the tab exposure region is determined according to the width of the tab end-portion staggered layer region, the width of the tab soldering region, the width of the pre-soldered press-fit region, the thickness of the at least one core, and a tab bending angle of the tab, wherein the width of the tab end-portion staggered layer region is d 1 d_1 , the tab soldering region is provided with a tab protection sheet, a width of the tab protection sheet in the first direction is d 2 d_2 , the width of the pre-soldered press-fit region is d 3 d_3 , the thickness of the at least one core is D, and the tab bending angle of any one tab in the plurality of tabs is A, the length of the exposed tab in the tab exposure region is L, and a relational expression L = d 1 + d 2 + d 3 + D / 2 * t a n A L=d_1+d_2+d_3+D / 2*tan A is satisfied.

2. The cell according to claim 1, wherein A satisfies a relational expression 45 ∘ ≤ A ≤ 135 ∘ 45^{\circ} \le A \le 135^{\circ} .

3. The cell according to claim 1, wherein a ratio of d 2 to d 1 is B, and satisfies a relational expression 4<B<10.

4. The cell according to claim 1 or 3, wherein a ratio of d 2 to d 3 is C, and satisfies a relational expression 4<C<24.

5. The cell according to claim 1 or 3 or 4, wherein a relational expression 0 mm<d 1 <8 mm is satisfied.

6. The cell according to claim 1 or any one of claims 3 to 5, wherein a relational expression 8 m m ≤ d 2 ≤ 12 mm mm \le d_2 \le 12 \text{ mm} is satisfied.

7. The cell according to claim 1 or any one of claims 3 to 6, wherein a relational expression 0.5 m m ≤ d 3 ≤ 2 mm mm \le d_3 \le 2 \text{ mm} is satisfied.

8. A battery, comprising the cell according to any one of claims 1 to 7.

9. A battery pack, comprising the battery according to claim 8.