Battery cell and battery

Abstract

The utility model discloses a battery cell and a battery, the battery cell comprises a battery cell body, the battery cell body comprises an anode pole piece, a diaphragm and a cathode pole piece which are mutually stacked and wound; the anode tab is provided with a first welding part and a first extension part, the first welding part is welded to the anode pole piece, and the first extension part extends from the first welding part and is exposed out of the anode pole piece in a protruding manner; the cathode tab is provided with a second welding part and a second extension part, the second welding part is welded to the cathode pole piece, and the second extension part extends from the second welding part and is exposed out of the cathode pole piece in a protruding manner; wherein at least one of the first welding part and the second welding part is provided with a single hollowed-out hole, and the area ratio of the area of the hollowed-out hole to the area of the tab where the hollowed-out hole is located is 20%-40%. According to the utility model, the safety performance of the acupuncture test of the battery cell is high.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, and particularly relates to a battery cell and a battery. Background Art

[0002] The lithium battery needle penetration test is to evaluate the heat and fire risks generated by a lithium battery when suffering external damage through a standardized test method and a battery needle penetration experiment under specific conditions.

[0003] When a lithium battery undergoes a needle penetration test experiment, internal short circuits are likely to occur between the positive and negative electrodes, instantaneously generating huge energy, resulting in a sharp rise in battery energy and temperature, causing thermal runaway of the battery cell, and then leading to a fire phenomenon. In related technologies, an empty foil area that can completely cover its circumference is usually provided at the tails of the anode electrode sheet and the cathode electrode sheet of the wound battery cell to prevent the needle from piercing the electrode sheet dressing during the needle penetration test and causing a short circuit instantaneously. However, when the steel needle reaches a certain speed, the steel needle is still likely to form a closed circuit by penetrating the anode tab and the cathode tab simultaneously, resulting in an increased current transmission, generating huge energy, and then thermal runaway causing a fire, with low safety performance. Summary of the Utility Model

[0004] The main object of the utility model is to propose a battery cell, aiming to solve the technical problem of low safety performance of the current battery cell during the needle penetration test.

[0005] To achieve the above object, the utility model proposes a battery cell, which includes:

[0006] A battery cell body, the battery cell body includes an anode electrode sheet, a separator, and a cathode electrode sheet that are stacked and wound with each other;

[0007] An anode tab, the anode tab has a first welding part and a first extension part, the first welding part is welded to the anode electrode sheet, and the first extension part extends and protrudes from the first welding part outside the anode electrode sheet;

[0008] A cathode tab, the cathode tab has a second welding part and a second extension part, the second welding part is welded to the cathode electrode sheet, and the second extension part extends and protrudes from the second welding part outside the cathode electrode sheet;

[0009] Wherein, at least one of the first welding part and the second welding part is provided with a single hollow hole, and the area ratio of the hollow hole to the area of the tab where it is located is 20% - 40%.

[0010] In some embodiments, the first welding part is provided with a first hollow hole, and the first hollow hole extends along the length direction of the anode tab.

[0011] In some embodiments, the ratio of the length of the first hollow hole to the length of the anode tab is 38% to 51%; and / or,

[0012] the ratio of the width of the first hollow hole to the width of the anode tab is 50% to 75%.

[0013] In some embodiments, the ratio of the area of the first hollow hole to the area of the anode tab is 26% to 39%.

[0014] In some embodiments, a second hollow hole is provided on the second welding portion, and the second hollow hole extends along the length direction of the cathode tab.

[0015] In some embodiments, the ratio of the length of the second hollow hole to the length of the cathode tab is 49% to 64%; and / or,

[0016] the ratio of the width of the second hollow hole to the width of the cathode tab is 50% to 75%.

[0017] In some embodiments, the ratio of the area of the second hollow hole to the area of the cathode tab is 24% to 35%.

[0018] In some embodiments, the shape of the hollow hole is oval or polygonal.

[0019] In some embodiments, the anode electrode sheet is sequentially provided with a first coating area for coating the dressing and a first empty foil area wound at least one turn from the inside to the outside along its winding direction, and the anode tab is located in the first empty foil area;

[0020] the cathode electrode sheet is sequentially provided with a second coating area for coating the dressing and a second empty foil area wound at least one turn from the inside to the outside along its winding direction, and the cathode tab is located in the second coating area.

[0021] The present invention also provides a battery, which includes a housing and the battery cell as described above, and the battery cell is disposed in the housing.

[0022] When the battery cell of the present invention is subjected to a needle puncture test, a steel needle punctures the battery cell body. If the steel needle reaches a certain speed and penetrates through the first welding portion of the anode tab and the second welding portion of the cathode tab at the same time, since at least one of the first welding portion and the second welding portion is provided with a single hollow hole, and the ratio of the area of the hollow hole to the area of the tab where it is located is 20% to 40%, the tab has a large-area hollow region, so that the tab can form an avoidance of the steel needle through the single hollow hole provided, thereby avoiding contact with the steel needle, and thus reducing the probability that the steel needle connects the cathode tab and the anode tab to form a closed circuit, greatly reducing the energy generated by an internal short circuit of the battery cell, avoiding ignition, and improving the safety performance. Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of the anode plate and the cathode plate of the battery cell in an embodiment of the present utility model;

[0024] Figure 2 It is a schematic structural diagram of the battery cell in an embodiment of the present utility model;

[0025] Figure 3 It is a schematic structural diagram of the anode plate and the anode tab in an embodiment of the present utility model;

[0026] Figure 4 It is a schematic structural diagram of the cathode plate and the cathode tab in an embodiment of the present utility model;

[0027] Explanation of the reference numerals in the drawings:

[0028] Label Name Label Name 100 Cell body 320 Second epitaxial part 110 Anode electrode L Hollow hole 120 Cathode electrode L1 First hollow hole 200 Anode tab L2 Second hollow hole 210 First welding part 111 First coating area 220 First epitaxial part 112 First empty foil area 300 Cathode tab 121 Second coating area 310 Second welding part 122 Second empty foil area

[0029] The realization, functional features and advantages of the object of the present utility model will be further described with reference to the embodiments and the accompanying drawings. Detailed Embodiments

[0030] Next, the solutions in the embodiments of the present utility model will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0031] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0032] It should also be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time.

[0033] In addition, the descriptions involving "first", "second", etc. in the present utility model are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions results in contradictions or cannot be realized, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0034] An embodiment of the present utility model provides a battery cell. Referring to Figures 1 to 4 , the battery cell includes: a battery cell body 100, an anode tab 200, and a cathode tab 300. The battery cell body 100 includes an anode plate 110, a separator, and a cathode plate 120 that are stacked and wound with each other; the anode tab 200 has a first welding portion 210 and a first extension portion 220. The first welding portion 210 is welded to the anode plate 110, and the first extension portion 220 extends from the first welding portion 210 and protrudes outside the anode plate 110; the cathode tab 300 has a second welding portion 310 and a second extension portion 320. The second welding portion 310 is welded to the cathode plate 120, and the second extension portion 320 extends from the second welding portion 310 and protrudes outside the cathode plate 120; wherein, at least one of the first welding portion 210 and the second welding portion 310 is provided with a single hollow hole L, and the area ratio of the hollow hole L to the area of the tab where it is located is 20% - 40%.

[0035] The battery cell of this embodiment mainly includes a battery cell body 100, an anode tab 200, and a cathode tab 300. The battery cell body 100 therein includes an anode plate 110, a separator, and a cathode plate 120. The separator is placed between the anode plate 110 and the cathode plate 120 to achieve the lamination of the three, and then wound to correspondingly form the battery cell body 100. As Figures 1 to 3 shown, both the anode tab 200 and the cathode tab 300 are strip-shaped tabs. For the anode tab 200, the first welding portion 210 and the first extension portion 220 of the anode tab 200 are integrally formed. The anode plate 110 is in a flat state before winding. The anode tab 200 is located on one side of the anode plate 110 and is welded to the anode plate 110 through its first welding portion 210, and its first extension portion 220 extends from the first welding portion 210 and protrudes outside the anode plate 110. As an optional size setting scheme, the length of the first welding portion 210 is less than or equal to the width of the anode plate 110, and the length of the first extension portion 220 is less than the length of the first welding portion 210. As Figure 4As shown, corresponding to the cathode tab 300, the second welding portion 310 and the second extension portion 320 of the cathode tab 300 are integrally formed. The cathode electrode sheet 120 is in a flat state during winding. The cathode tab 300 is located on one side of the cathode electrode sheet 120 and is welded to the cathode electrode sheet 120 through its second welding portion 310, while its second extension portion 320 extends from the second welding portion 310 and protrudes outside the cathode electrode sheet 120. As an optional dimension setting scheme, the length of the second welding portion 310 is less than or equal to the width of the cathode electrode sheet 120, and the length of the second extension portion 320 is less than the length of the second welding portion 310.

[0036] Furthermore, for the first welding portion 210 of the anode tab 200 and the second welding portion 310 of the cathode tab 300, a single hollow hole L is provided on at least one of them. That is, a single hollow hole L can be provided on the first welding portion 210 of the anode tab 200, or a single hollow hole L can be provided on the second welding portion 310 of the cathode tab 300, or a single hollow hole L can be provided on the first welding portion 210 of the anode tab 200 and the second welding portion 310 of the cathode tab 300 respectively. The shape of the hollow hole L can be various, such as rectangular, diamond-shaped, etc., and this embodiment does not limit this.

[0037] Among them, when a single hollow hole L is provided on the first welding portion 210 of the anode tab 200, the area of the hollow hole L on the first welding portion 210 of the anode tab 200 accounts for 20% - 40% of the area of the anode tab 200. The specific proportional value can be set according to the situation to make the anode tab 200 have a larger hollow area. When a single hollow hole L is provided on the second welding portion 310 of the cathode tab 300, the area of the hollow hole L on the second welding portion 310 of the cathode tab 300 accounts for 20% - 40% of the area of the cathode tab 300. The specific proportional value can be set according to the situation to make the cathode tab 300 have a larger hollow area. The hollow hole L provided on the tab can be used for avoidance. Specifically, during the pinprick test of the battery cell, if the steel needle pricks the tab, it will correspondingly pass through the hollow hole L, and the hollow hole L on the tab avoids the steel needle, thereby preventing contact between the steel needle and the tab.

[0038] Optionally, when a single hollow hole L is provided on the first welding portion 210 of the anode tab 200 and the second welding portion 310 of the cathode tab 300 respectively, the hollow holes L of the two at least partially overlap, that is, they can only partially overlap or completely overlap. Optionally,

[0039] When the battery cell is undergoing a needle penetration test, a steel needle penetrates the battery cell body 100. If the steel needle reaches a certain speed and simultaneously penetrates the first welding part 210 of the anode tab 200 and the second welding part 310 of the cathode tab 300, since at least one of the first welding part 210 and the second welding part 310 is provided with a single hollow hole L, and the area of the hollow hole L accounts for 20% - 40% of the area of the tab where it is located, the tab has a relatively large area of hollow region. Thus, the tab can form an avoidance of the steel needle through the single hollow hole L provided, thereby avoiding contact with the steel needle, reducing the probability that the steel needle connects the cathode tab 300 and the anode tab 200 to form a closed circuit, greatly reducing the energy generated by an internal short circuit in the battery cell, avoiding fire, and improving safety performance.

[0040] In some embodiments, referring to Figure 2 and Figure 3 , a first hollow hole L1 is provided on the first welding part 210, and the first hollow hole L1 extends along the length direction of the anode tab 200. Specifically, during the needle penetration experiment of the battery cell, the needle penetration position of the steel needle is usually the middle position in the height direction of the battery cell body 100, and the first welding part 210 of the anode tab 200 correspondingly passes through the middle position in the height direction of the battery cell body 100. In this embodiment, by providing the first hollow hole L1 on the first welding part 210 of the anode tab 200, and the first hollow hole L1 extends along the length direction of the anode tab 200. In this way, during the needle penetration experiment of the battery cell, if the steel needle penetrates the anode tab 200, it will correspondingly penetrate to the position of the first hollow hole L1 provided on its first welding part 210. The first hollow hole L1 avoids the steel needle, thereby avoiding contact between the steel needle and the anode tab 200, reducing the probability that the steel needle connects the cathode tab 300 and the anode tab 200 to form a closed circuit, greatly reducing the energy generated by an internal short circuit in the battery cell, avoiding fire, and improving safety performance.

[0041] In some embodiments, the proportion of the length of the first hollow hole L1 to the length of the anode tab 200 is 38% to 51%. In this embodiment, the proportion of the length of the first hollow hole L1 to the length of the anode tab 200 can be set within the range of 38% to 51%. For example, the proportion of the length of the first hollow hole L1 to the length of the anode tab 200 can be set to 38%, 45%, or 51%. According to the set length ratio relationship, when the length of the fabricated anode tab 200 changes, the length of the first hollow hole L1 changes with the change in the length of the anode tab 200. Since the specification size of the steel needle is usually fixed, the length of the first hollow hole L1 does not need to be set too large, as long as it is suitable for avoiding the steel needle. As an example, the proportion of the length of the first hollow hole L1 to the length of the anode tab 200 can be set with reference to the length of the tab. When the length of the anode tab 200 is relatively long, the proportion of the length of the first hollow hole L1 to the length of the anode tab 200 can be set at a small ratio, such as 38%; when the length of the anode tab 200 is medium, the proportion of the length of the first hollow hole L1 to the length of the anode tab 200 can be set at a medium ratio, such as 45%; when the length of the anode tab 200 is relatively short, the proportion of the length of the first hollow hole L1 to the length of the anode tab 200 can be set at a large ratio, such as 45%. Of course, in addition to this, the proportion of the length of the first hollow hole L1 to the length of the anode tab 200 can also be set with reference to other settings, and there is no limitation on this.

[0042] And / or, in some embodiments, the ratio of the width of the first hollow hole L1 to the width of the anode tab 200 is 50% to 75%. In this embodiment, the ratio of the width of the first hollow hole L1 to the width of the anode tab 200 can be set within the range of 50% to 75%. For example, the ratio of the width of the first hollow hole L1 to the width of the anode tab 200 can be set to 50%, 63% or 75%. According to the set width ratio relationship, when the width of the fabricated anode tab 200 changes, the width of the first hollow hole L1 changes with the change of the width of the anode tab 200. Since the specification size of the steel needle is usually fixed, the width of the first hollow hole L1 does not need to be set too large, as long as it is suitable for avoiding the steel needle. As an example, the ratio of the length of the first hollow hole L1 to the width of the anode tab 200 can be set with reference to the width of the tab. When the width of the anode tab 200 is relatively wide, the ratio of the width of the first hollow hole L1 to the width of the anode tab 200 can be set at a small ratio, such as 50%; when the width of the anode tab 200 is medium, the ratio of the width of the first hollow hole L1 to the width of the anode tab 200 can be set at a medium ratio, such as 63%; when the width of the anode tab 200 is relatively narrow, the ratio of the width of the first hollow hole L1 to the width of the anode tab 200 can be set at a large ratio, such as 75%. Of course, in addition to this, the ratio of the width of the first hollow hole L1 to the width of the anode tab 200 can also be set with reference to other settings, and there is no limitation on this.

[0043] In some embodiments, the proportion of the area of the first hollow hole L1 to the area of the anode tab 200 is 26% to 39%. In this embodiment, the proportion of the area of the first hollow hole L1 to the area of the anode tab 200 can be set within the range of 26% to 39%. For example, the proportion of the area of the first hollow hole L1 to the area of the anode tab 200 can be set to 26%, 33%, or 39%. According to the set area ratio relationship, when the area of the manufactured anode tab 200 changes, the area of the first hollow hole L1 changes with the change of the area of the anode tab 200. Since the specification size of the steel needle is usually fixed, the width of the first hollow hole L1 does not need to be set too large, as long as it is suitable for avoiding the steel needle. As an example, the proportion of the area of the first hollow hole L1 to the area of the anode tab 200 can be set with reference to the area of the tab. When the area of the anode tab 200 is large, the proportion of the area of the first hollow hole L1 to the area of the anode tab 200 can be set at a small ratio, such as 26%; when the area of the anode tab 200 is medium, the proportion of the area of the first hollow hole L1 to the area of the anode tab 200 can be set at a medium ratio, such as 33%; when the area of the anode tab 200 is small, the proportion of the area of the first hollow hole L1 to the area of the anode tab 200 can be set at a large ratio, such as 39%. Of course, in addition, the proportion of the area of the first hollow hole L1 to the area of the anode tab 200 can also be set with reference to other settings, and there is no limitation on this.

[0044] In some embodiments, referring to Figure 4 , a second hollow hole L2 is provided on the second welding portion 310, and the second hollow hole L2 extends along the length direction of the cathode tab 300. Specifically, during the needle puncture experiment of the battery cell, the puncture position of the steel needle is usually the middle position in the height direction of the battery cell body 100, and the second welding portion 310 of the cathode tab 300 correspondingly passes through the middle position in the height direction of the battery cell body 100. In this embodiment, by providing the second hollow hole L2 on the second welding portion 310 of the cathode tab 300, and the second hollow hole L2 extends along the length direction of the cathode tab 300. Thus, in the needle puncture experiment of the battery cell, if the steel needle punctures the cathode tab 300, it will correspondingly puncture the second hollow hole L2 provided on its second welding portion 310. The second hollow hole L2 avoids the steel needle, thereby preventing the steel needle from contacting the cathode tab 300, reducing the probability of the steel needle connecting the cathode tab 300 and the anode tab 200 to form a closed circuit, greatly reducing the energy generated by the internal short circuit of the battery cell, avoiding ignition, and improving the safety performance.

[0045] In some embodiments, the ratio of the length of the second hollow hole L2 to the length of the cathode tab 300 is 49% to 64%. In this embodiment, the ratio of the length of the second hollow hole L2 to the length of the cathode tab 300 can be set within the range of 49% to 64%. For example, the ratio of the length of the second hollow hole L2 to the length of the cathode tab 300 can be set to 49%, 57%, or 64%. According to the set length ratio relationship, when the length of the manufactured cathode tab 300 changes, the length of the second hollow hole L2 changes with the change of the length of the cathode tab 300. Since the specification size of the steel needle is usually fixed, the length of the second hollow hole L2 does not need to be set too large, as long as it is suitable for avoiding the steel needle. As an example, the ratio of the length of the second hollow hole L2 to the length of the cathode tab 300 can be set with reference to the length of the tab. When the length of the cathode tab 300 is long, the ratio of the length of the second hollow hole L2 to the length of the cathode tab 300 can be set at a small ratio, such as 49%. When the length of the cathode tab 300 is medium, the ratio of the length of the second hollow hole L2 to the length of the cathode tab 300 can be set at a medium ratio, such as 57%. When the length of the cathode tab 300 is short, the ratio of the length of the second hollow hole L2 to the length of the cathode tab 300 can be set at a large ratio, such as 64%. Of course, in addition to this, the ratio of the length of the second hollow hole L2 to the length of the cathode tab 300 can also refer to other settings, and there is no limitation on this.

[0046] And / or, in some embodiments, the ratio of the width of the second hollow hole L2 to the width of the cathode tab 300 is 50% to 75%. In this embodiment, the ratio of the width of the second hollow hole L2 to the width of the cathode tab 300 can be set within the range of 50% to 75%. For example, the ratio of the width of the second hollow hole L2 to the width of the cathode tab 300 can be set to 50%, 63%, or 75%. According to the set width ratio relationship, when the width of the manufactured cathode tab 300 changes, the width of the second hollow hole L2 changes with the change of the width of the cathode tab 300. Since the specification size of the steel needle is usually fixed, the width of the second hollow hole L2 does not need to be set too large, as long as it is suitable for avoiding the steel needle. As an example, the ratio of the length of the second hollow hole L2 to the width of the cathode tab 300 can be set with reference to the width of the tab. When the width of the cathode tab 300 is relatively wide, the ratio of the width of the second hollow hole L2 to the width of the cathode tab 300 can be set at a small ratio, such as 50%; when the width of the cathode tab 300 is medium, the ratio of the width of the second hollow hole L2 to the width of the cathode tab 300 can be set at a medium ratio, such as 63%; when the width of the cathode tab 300 is relatively narrow, the ratio of the width of the second hollow hole L2 to the width of the cathode tab 300 can be set at a large ratio, such as 75%. Of course, in addition to this, the ratio of the width of the second hollow hole L2 to the width of the cathode tab 300 can also be set with reference to other settings, and there is no limitation on this.

[0047] In some embodiments, the proportion of the area of the second hollow hole L2 to the area of the cathode tab 300 is 24% - 35%. In this embodiment, the proportion of the area of the second hollow hole L2 to the area of the cathode tab 300 can be set within the range of 24% - 35%. For example, the proportion of the area of the second hollow hole L2 to the area of the cathode tab 300 can be set to 24%, 30%, or 35%. According to the set area ratio relationship, when the area of the fabricated cathode tab 300 changes, the area of the second hollow hole L2 changes with the change of the area of the cathode tab 300. Since the specification size of the steel needle is usually fixed, the width of the second hollow hole L2 does not need to be set too large, as long as it is suitable for avoiding the steel needle. As an example, the proportion of the area of the second hollow hole L2 to the area of the cathode tab 300 can be set with reference to the area of the tab. When the area of the cathode tab 300 is large, the proportion of the area of the second hollow hole L2 to the area of the cathode tab 300 can be set at a small ratio, such as 24%; when the area of the cathode tab 300 is medium, the proportion of the area of the second hollow hole L2 to the area of the cathode tab 300 can be set at a medium ratio, such as 30%; when the area of the cathode tab 300 is small, the proportion of the area of the second hollow hole L2 to the area of the cathode tab 300 can be set at a large ratio, such as 35%. Of course, in addition to this, the proportion of the area of the second hollow hole L2 to the area of the cathode tab 300 can also be set with reference to other settings, and there is no limitation on this.

[0048] In some embodiments, referring to Figures 2 to 4 , the shape of the hollow hole L is oval or polygonal. In this embodiment, the shape of the hollow hole L can be set to oval, and the narrower ends of the hollow hole L extend along the length direction of the tab. Alternatively, the shape of the hollow hole L can be set to polygonal, and the polygon can be a rectangle, a rhombus, etc.

[0049] In some embodiments, referring to Figure 1 and Figure 2 , on the anode plate 110, a first coating area 111 for coating the dressing and at least one turn of a first empty foil area 112 are sequentially arranged from the inside to the outside along its winding direction, and the anode tab 200 is located in the first empty foil area 112;

[0050] On the cathode plate 120, a second coating area 121 for coating the dressing and at least one turn of a second empty foil area 122 are sequentially arranged from the inside to the outside along its winding direction, and the cathode tab 300 is located in the second coating area 122.

[0051] After the anode electrode sheet 110 is wound, an inner circle and an outer circle are correspondingly formed. Among them, the first coating area 111 provided on the anode electrode sheet 110 is coated with a dressing and is correspondingly located in the inner circle, while the first blank foil area 112 is not coated with a dressing and is correspondingly located in the outer circle. The first blank foil area 112 winds at least one circle along the winding direction in the outer circle. Correspondingly, after the cathode electrode sheet 120 is wound, an inner circle and an outer circle are correspondingly formed. Among them, the second coating area 121 provided on the cathode electrode sheet 120 is coated with a dressing and is correspondingly located in the inner circle, while the second blank foil area 122 is not coated with a dressing and is correspondingly located in the outer circle. The second blank foil area 122 winds at least one circle along the winding direction in the outer circle.

[0052] When the battery cell is subjected to a needle penetration test, the steel needle first penetrates the first blank foil area 112 of the anode electrode sheet 110 and the second blank foil area 122 of the cathode electrode sheet 120 on the periphery of the battery cell body 100. Since both the first blank foil area 112 of the anode electrode sheet 110 and the second blank foil area 122 of the cathode electrode sheet 120 are provided with empty materials, it is possible to prevent a short circuit from occurring instantaneously and generating a huge amount of energy.

[0053] An embodiment of the present invention further provides a battery, which includes a housing and a battery cell as described in the foregoing embodiment, and the battery cell is disposed in the housing. The specific structure of the battery cell refers to the above embodiment. Since this battery adopts all the technical solutions of the above all embodiments, it at least has all the technical effects brought by the technical solutions of the above embodiments, and will not be elaborated here one by one. Among them, the battery can be a lithium battery.

[0054] The above are only partial or preferred embodiments of the present invention. Whether in terms of text or drawings, the scope of protection of the present invention cannot be limited thereby. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the overall concept of the present invention, or any direct / indirect application in other related technical fields is included in the scope of protection of the present invention.

Claims

1. A battery cell, characterized in that, Comprising: A battery cell body, the battery cell body comprising an anode electrode sheet, a separator, and a cathode electrode sheet that are stacked and wound together; An anode tab, the anode tab having a first welding portion and a first extension portion, the first welding portion being welded to the anode electrode sheet, and the first extension portion extending from the first welding portion and protruding outside the anode electrode sheet; A cathode tab, the cathode tab having a second welding portion and a second extension portion, the second welding portion being welded to the cathode electrode sheet, and the second extension portion extending from the second welding portion and protruding outside the cathode electrode sheet; Wherein, at least one of the first welding portion and the second welding portion is provided with a single hollow hole, and the area of the hollow hole accounts for 20% to 40% of the area of the tab where it is located.

2. The battery cell according to claim 1, characterized in that, The first welding portion is provided with a first hollow hole, and the first hollow hole extends along the length direction of the anode tab.

3. The battery cell according to claim 2, characterized in that, The length of the first hollow hole accounts for 38% to 51% of the length of the anode tab; and / or, The width of the first hollow hole accounts for 50% to 75% of the width of the anode tab.

4. The battery cell according to claim 2, wherein, The area of the first hollow hole accounts for 26% to 39% of the area of the anode tab.

5. The battery cell according to claim 1, wherein The second welding portion is provided with a second hollow hole, and the second hollow hole extends along the length direction of the cathode tab.

6. The battery cell according to claim 5, wherein, The length of the second hollow hole accounts for 49% to 64% of the length of the cathode tab; and / or, The width of the second hollow hole accounts for 50% to 75% of the width of the cathode tab.

7. The cell according to claim 5, characterized in that The area of the second hollow hole accounts for 24% to 35% of the area of the cathode tab.

8. The battery cell according to any one of claims 1 to 7, characterized in that, The shape of the hollow hole is oval or polygonal.

9. The battery cell according to any one of claims 1 to 7, characterized in that, The anode electrode sheet is sequentially provided with a first coating area for coating a dressing and a first empty foil area wound at least one turn from the inside to the outside along its winding direction, and the anode tab is located in the first empty foil area; The cathode electrode sheet is sequentially provided with a second coating area for coating a dressing and a second empty foil area wound at least one turn from the inside to the outside along its winding direction, and the cathode tab is located in the second coating area.

10. A battery, characterized in that, Comprising a housing and a battery cell as described in any one of claims 1 to 9, the battery cell being disposed in the housing.

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