CN220439816U - Battery and battery device - Google Patents

Abstract

The utility model relates to the technical field of batteries, in particular to a battery and a battery device, wherein the battery comprises an electrode pole piece and an electrode output terminal, the electrode pole piece comprises a current collector, an active material layer and a conductive extension piece, the active material layer is arranged in a partial area on the surface of the current collector, the current collector is provided with an electric connection area, the electric connection area is positioned in an area where the active material layer is not arranged on the current collector, the conductive extension piece is provided with a first end part and a second end part, the first end part is connected with the electrode output terminal, the second end part is overlapped with the electric connection area, the first part of the second end part is welded with the electric connection area to form a connection area, and the second part of the second end part is positioned at one side of the first part, which is close to the active material layer; the length of the second part is a first length along the extending direction of the electric connection area, the distance between one end of the connection area, which is close to the active material layer, and the active material layer is a second length, and the ratio of the first length to the second length is 0.1-0.9.

Description

Battery and battery device

Technical Field

The present utility model relates to the field of battery technologies, and in particular, to a battery and a battery device.

Background

When the electrode plate of the battery adopts the design of the composite current collector, the composite current collector is provided with a non-conductive high polymer layer, so that the composite current collector of the multi-plate electrode plate cannot be directly welded. For this, a conductive splice tab is welded to the composite current collector. However, in the design scheme of the existing battery, the welding positions of the spliced electrode lugs and the composite current collector are improperly arranged, so that the problem that the welding area of the spliced electrode lugs and the composite current collector is insufficient, the welding effect is affected, the overcurrent requirement of the electrode pole pieces is difficult to meet, or the problem that the spliced electrode lugs and the high polymer layer are partially overlapped, uneven or even wrinkles are generated in the overlapped area after a plurality of electrode pole pieces are overlapped, lithium precipitation of the negative electrode pole pieces is caused, and the electric performance of the battery is reduced.

Disclosure of Invention

It is a primary object of the present utility model to overcome at least one of the above-mentioned drawbacks of the prior art by providing a battery in which the welding area of the conductive extension and the current collector is sufficient and overlapping with the active material layer is avoided.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

according to one aspect of the present utility model, there is provided a battery including an electrode tab including a current collector including a base layer and two conductive layers respectively provided on opposite surfaces of the base layer, an active material layer provided on a partial region of the surface of the current collector, and an electrode output terminal, the current collector having an electrical connection region in a region where the active material layer is not provided, and an electrode extension having a first end portion connected to the electrode output terminal and a second end portion overlapping the electrical connection region, a first portion of the second end portion being welded to the electrical connection region to form a connection region, and a second portion of the second end portion being located on a side of the first portion adjacent to the active material layer; the length of the second portion is a first length along the extending direction of the electric connection area, the distance between one end of the connection area, which is close to the active material layer, and the active material layer is a second length, and the ratio of the first length to the second length is 0.1-0.9.

According to the technical scheme, the battery provided by the utility model has the advantages and positive effects that:

the electrode plate of the battery comprises a current collector, an active material layer and a conductive extension piece, wherein a first end part of the conductive extension piece is connected with an electrode output terminal, a second end part of the conductive extension piece is provided with a first part and a second part, the first part is welded and connected with an electric connection area of the current collector to form a connection area, and the second part is positioned on one side of the first part, which is close to the active material layer. The length of the second part is a first length, the distance between one end of the connecting area, which is close to the active material layer, and the active material layer is a second length, and the ratio of the first length to the second length is 0.1-0.9. Through the design, the second part of the second end part of the conductive extension piece is prevented from being far away from the active material layer, so that the electric connection area of the first part of the second end part and the current collector is ensured to have enough welding area, the effective welding of the conductive extension piece and the current collector is ensured, and the overcurrent requirement of the electrode pole piece is met. Meanwhile, the utility model can avoid the second part from being too close to the active substance, thereby avoiding the second part from overlapping the active substance layer due to factors such as machining tolerance, positioning error and the like in the assembly process, ensuring the flatness of a plurality of electrode plates after overlapping, avoiding the occurrence of lithium precipitation of the negative electrode plate and ensuring the electrical property of the battery.

Another main object of the present utility model is to overcome at least one of the above drawbacks of the prior art, and to provide a battery device that can meet the overcurrent requirements of the electrode tab and has stable electrical properties.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

according to another aspect of the present utility model, there is provided a battery device, including the battery according to the present utility model.

As can be seen from the above technical solutions, the battery device provided by the present utility model has the following advantages and positive effects:

the battery device provided by the utility model can meet the overcurrent requirement of the electrode plate and ensure the electrical property of the battery.

Drawings

Various objects, features and advantages of the present utility model will become more apparent from the following detailed description of the preferred embodiments of the utility model, when taken in conjunction with the accompanying drawings. The drawings are merely exemplary illustrations of the utility model and are not necessarily drawn to scale. In the drawings, like reference numerals refer to the same or similar parts throughout. Wherein:

fig. 1 is a schematic perspective view of an electrode tab of a battery according to an exemplary embodiment;

FIG. 2 is an enlarged schematic view of portion A of FIG. 1;

FIG. 3 is a schematic plan view of FIG. 1;

FIG. 4 is an enlarged schematic view of portion B of FIG. 3;

FIG. 5 is a cross-sectional view taken along line C-C of FIG. 4;

fig. 6 to 8 are partial sectional views of electrode tabs of a battery according to several other exemplary embodiments, respectively;

fig. 9 is an enlarged partial schematic view of an electrode tab of a battery according to another exemplary embodiment.

The reference numerals are explained as follows:

100. electrode pole pieces;

110. a current collector;

111. an electrical connection region;

120. an active material layer;

130. a conductive extension;

131. a first end;

132. a second end;

1321. a first portion;

1322. a second portion;

133. a connection region;

140. a glue layer;

200. an electrode output terminal;

l1, a first length;

l2. second length.

Detailed Description

Exemplary embodiments that embody features and advantages of the present utility model are described in detail in the following description. It will be understood that the utility model is capable of various modifications in various embodiments, all without departing from the scope of the utility model, and that the description and drawings are intended to be illustrative in nature and not to be limiting.

In the following description of various exemplary embodiments of the utility model, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various exemplary structures, systems, and steps in which aspects of the utility model may be practiced. It is to be understood that other specific arrangements of parts, structures, example devices, systems, and steps may be utilized and structural and functional modifications may be made without departing from the scope of the present utility model. Moreover, although the terms "over," "between," "within," and the like may be used in this description to describe various exemplary features and elements of the utility model, these terms are used herein for convenience only, e.g., in terms of the orientation of the examples depicted in the drawings. Nothing in this specification should be construed as requiring a particular three-dimensional orientation of the structure in order to fall within the scope of the utility model.

Referring to fig. 1, there is representatively illustrated a schematic perspective view of an electrode tab 100 of a battery according to the present utility model. In this exemplary embodiment, the battery proposed by the present utility model is described as being applied to a vehicle-mounted battery as an example. Those skilled in the art will readily appreciate that many modifications, additions, substitutions, deletions, or other changes may be made to the specific embodiments described below in order to adapt the relevant designs of the present utility model to other types of battery devices, and such changes are still within the principles of the battery presented herein.

As shown in fig. 1, in an embodiment of the present utility model, a battery according to the present utility model includes an electrode tab 100 and an electrode output terminal 200. Referring to fig. 2-5 in conjunction, an enlarged schematic view of portion a of fig. 1 is representatively illustrated in fig. 2; FIG. 3 representatively illustrates a plan view of FIG. 1; an enlarged schematic view of portion B of fig. 3 is representatively illustrated in fig. 4; a cross-sectional view taken along line C-C in fig. 4 is representatively illustrated in fig. 5. The structure, connection mode and functional relationship of the main components of the battery according to the present utility model will be described in detail with reference to the above drawings.

As shown in fig. 1 to 5, in an embodiment of the present utility model, the electrode tab 100 includes a current collector 110, an active material layer 120, and a conductive extension 130. The current collector 110 includes a substrate layer and two conductive layers disposed on opposite surfaces of the substrate layer. The active material layer 120 is disposed on a partial area of the surface of the current collector 110, specifically, the active material layer 120 is disposed on a surface of the conductive layer facing away from the substrate layer, the current collector 110 has an electrical connection area 111, and the electrical connection area 111 is located in an area of the current collector 110 where the active material layer 120 is not disposed. The conductive extension 130 has a first end 131 and a second end 132, the first end 131 is connected to the electrode output terminal 200, the second end 132 overlaps the electrical connection region 111 of the current collector 110, and a first portion 1321 of the second end 132 is welded to the electrical connection region 111 to form a connection region 133, and a second portion 1322 of the second end 132 is located at a side of the first portion 1321 near the active material layer 120. On the basis, along the extending direction of the electrical connection region 111, the length of the second portion 1322 is a first length L1, the distance between the end of the connection region 133 near the active material layer 120 and the active material layer 120 is a second length L2, and the ratio of the first length L1 to the second length L2 is 0.1 to 0.9, for example, 0.1, 0.12, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.75, 0.8, 0.85, 0.9, etc. Through the design, the second part 1322 of the second end 132 of the conductive extension member 130 is prevented from being far away from the active material layer 120, so that the first part 1321 of the second end 132 and the electric connection region 111 of the current collector 110 are ensured to have enough welding area, the effective welding of the conductive extension member 130 and the current collector 110 is ensured, and the overcurrent requirement of the electrode plate 100 is met. Meanwhile, the utility model can avoid the second part 1322 from being too close to the active substance, thereby avoiding the second part 1322 from overlapping the active substance layer 120 due to factors such as processing tolerance, positioning error and the like in the assembly process, ensuring the flatness of a plurality of electrode slices 100 after overlapping, avoiding the occurrence of lithium precipitation of the negative electrode slices 100 and ensuring the electrical property of the battery.

Specifically, when the electrical connection region 111 of the current collector 110 is welded to the conductive extension member 130, the length of the connection region 133 does not coincide with the length of the overlapping portion (i.e., the second end 132) of the two, so that after the second end 132 of the conductive extension member 130 is welded to the electrical connection region 111, there is a free end (i.e., the second portion 1322) that is not fixed to the current collector 110. If the edge of the side of the conductive extension 130 facing the active material layer 120 and the edge of the connection region 133 are designed to be completely identical, or the distance between them is too short (e.g., the ratio of the first length L1 to the second length L2 is less than 0.1), then during the welding process, the machining tolerance may cause the connection region 133 to deviate toward the active material layer 120, resulting in insufficient actual welding area, and thus, the overcurrent requirement of the electrode tab 100 cannot be satisfied. Furthermore, when the length of the free end is too large (for example, the ratio of the first length L1 to the second length L2 is greater than 0.9), the machining tolerance may cause the free end to exceed the portion of the electrical connection region 111, and cause the free end to overlap with the active material layer 120, where the interface of the multilayer electrode sheet 100 at the overlapping region may be uneven after the multilayer electrode sheet 100 in the battery is overlapped and cold-pressed, and the ion transmission path at the overlapping region is blocked by the free end, which may cause the electrode sheet 100 to wrinkle during the cycling, and may also cause the negative electrode sheet 100 to generate lithium precipitation, thereby reducing the electrical performance of the battery.

As shown in fig. 2 to 5, in an embodiment of the present utility model, the area of the connection region 133 is smaller than the overlapping area of the second end 132 and the electrical connection region 111. The first portion 1321 of the second end 132 and the electrical connection region 111 may be connected by spot welding, and the connection region 133 may be composed of a plurality of welding spots arranged. Furthermore, the first portion 1321 of the second end 132 and the electrical connection region 111 may be integrally welded together, and the connection region 133 may have an elongated structure. In some embodiments, the first portion 1321 of the second end 132 and the electrical connection region 111 may be connected by other specific welding methods, so that the connection region 133 may have other shapes and structures, which is not limited to this embodiment.

As shown in fig. 2 and 5, in an embodiment of the present utility model, the current collector 110 may include a substrate layer and two conductive layers, the two conductive layers are respectively disposed on all areas of opposite surfaces of the substrate layer, and the two active material layers 120 are respectively disposed on surfaces of the two conductive layers facing away from the substrate layer. Since the two active material layers 120 are disposed only in a partial area of the current collector 110, that is, a partial area corresponding to a surface of the conductive layer facing away from the substrate layer is not provided with the active material layers 120, and the current collector 110 of the electrical connection region 111 also includes the substrate layer and the two conductive layers, the second end 132 of the conductive extension 130 is welded to the conductive layer via the first portion 1321 and forms the connection region 133.

Based on the design that the current collector 110 includes a substrate layer, in an embodiment of the utility model, the substrate layer may be made of one of PET, PP, PE, OPP, PI, PVC, ABS, PA, POM, PC, PA and PA 66.

Referring to fig. 6, there is representatively illustrated a partial cross-sectional view of an electrode sheet 100 in another exemplary embodiment of a battery capable of embodying principles of the present utility model in fig. 6, with particular reference to fig. 5 in the cut-out position of fig. 4.

As shown in fig. 6, in an embodiment of the present utility model, the surface of the partial region of the current collector 110 where the active material layer 120 is disposed is not parallel to the connection contact surface of the first end portion 131 and the electrode output terminal 200, in other words, the electrical connection region 111 of the current collector 110 is bent in the thickness direction of the electrode tab 100, and the second end portion 132 of the conductive extension 130 is located inside the electrical connection region 111 in the bending direction of the above-described bending structure. On this basis, the ratio of the first length L1 to the second length L2 may be further 0.1 to 0.8, for example 0.1, 0.12, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.65, 0.7, 0.75, 0.8, etc. By the above design, since the second end 132 of the conductive extension member 130 can be located at the inner side of the bending direction of the electrical connection region 111, compared with the embodiment shown in fig. 1 to 5, the second portion 1322 of the conductive extension member 130 in this embodiment is closer to the active material layer 120 after bending along with the electrical connection region 111 and forms a certain angle with the plane of the electrode sheet 100, and in this aspect, the upper limit value of the ratio of the first length L1 to the second length L2 is further reduced, so as to ensure that the second portion 1322 does not abut against or cover the active material layer 120, thereby avoiding scraping powder of the active material layer 120 and damaging the interface thereof, and in addition, avoiding the second portion 1322 from piercing the current collector 110 of the electrode sheet 100 and connecting adjacent positive and negative electrode sheets, so as to cause a short circuit inside the battery.

Referring to fig. 7, a partial cross-sectional view of an electrode tab 100 of a battery capable of embodying the principles of the present utility model in another exemplary embodiment is representatively illustrated in fig. 7 and may be illustrated in a cut-out position in particular in reference to fig. 5 in the cut-out position of fig. 4.

As shown in fig. 7, in an embodiment of the present utility model, still taking a design in which the surface of the partial region of the current collector 110 provided with the active material layer 120 is not parallel to the connection contact surface of the first end portion 131 and the electrode output terminal 200 as an example, that is, a design in which the electrical connection region 111 of the current collector 110 is bent in the thickness direction of the electrode tab 100 as an example, the second end portion 132 of the conductive extension member 130 may be located outside the electrical connection region 111 in the bending direction of the above-described bending structure. On this basis, the ratio of the first length L1 to the second length L2 may be further 0.1 to 0.8, for example 0.1, 0.12, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.65, 0.7, 0.75, 0.8, etc. With the above design, since the second end 132 of the conductive extension member 130 can be located outside the bending direction of the electrical connection region 111, compared with the embodiment shown in fig. 1 to 5, the second portion 1322 of the conductive extension member 130 in the embodiment is in a tilted state, and in this way, the upper limit value of the ratio of the first length L1 to the second length L2 is further reduced, so that the possibility that the tilted second portion 1322 overlaps the battery case is reduced, and the battery is prevented from being shorted.

Based on the design that the current collector includes two conductive layers, in an embodiment of the present utility model, the conductive extension 130 may have two second ends 132, the two second ends 132 are connected to the first ends 131, respectively, and the two second ends 132 are connected to the two conductive layers of the electrical connection region 111 of the current collector 110, respectively. Wherein the surface of the partial region of the current collector 110 provided with the active material layer 120 is not parallel to the connection contact surface of the first end portion 131 and the electrode output terminal 200, i.e., the electric connection region 111 is bent in the thickness direction of the electrode tab 100, and the two second end portions 132 are respectively located inside and outside the electric connection region 111 in the bending direction. On the basis, the ratio of the first length L1 to the second length L2 may be further 0.1 to 0.8, for example, 0.1, 0.12, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.65, 0.7, 0.75, 0.8, etc., for any one of the second end portions 132.

Referring to fig. 8, a partial cross-sectional view of an electrode tab 100 of a battery capable of embodying the principles of the present utility model in another exemplary embodiment is representatively illustrated in fig. 8 and may be illustrated in a cut-out position in particular in reference to fig. 5 in the cut-out position of fig. 4.

As shown in fig. 8, in an embodiment of the present utility model, still taking a design in which the electrical connection region 111 has a bent structure and the second end 132 is located outside in the bending direction of the electrical connection region 111 as an example, an edge of the second portion 1322 of the second end 132 may be adhered and fixed between the edge of the second portion 1322 and the electrical connection region 111 of the current collector 110 through the adhesive layer 140. Through the design, the second portion 1322 of the second end 132 of the conductive extension member 130 can be fixed by using the adhesive layer 140, so that the second portion 1322 is prevented from tilting when the electrical connection region 111 is in a bent structure, and the problem of short circuit of the battery caused by overlapping of the second portion 1322 and the battery housing is avoided, and the safety of the battery is further ensured.

Based on the design that the edge of the second portion 1322 is adhered to and fixed to the electrical connection region 111 by the adhesive layer 140, in an embodiment of the present utility model, the ratio of the first length L1 to the second length L2 may be further 0.15 to 0.8, for example, 0.15, 0.16, 0.17, 0.19, 0.2, 0.25, 0.3, 0.4, 0.5, 0.65, 0.7, 0.75, 0.8, and the like. Through the above design, the lower limit value of the ratio of the first length L1 to the second length L2 is further increased, so that when the adhesive layer 140 is provided, the moment of the second portion 1322 is prevented from being shorter due to too small length, and the second portion is difficult to bend along with the electrical connection region 111. Furthermore, when the adhesive layer 140 is disposed, if a gap still exists between the second portion 1322 and the electrical connection region 111, the adhesive layer 140 is easy to fail after a long time, and the present utility model can avoid the occurrence of the gap, and ensure the effectiveness of the adhesive layer 140.

Based on the design that the edge of the second portion 1322 is adhered to and fixed to the electrical connection region 111 by the adhesive layer 140, in an embodiment of the present utility model, the adhesive layer 140 may be an insulating adhesive layer. Through the design, the utility model can avoid the problem of short circuit of the battery caused by overlapping of the second part 1322 and the battery shell, and further ensure the safety of the battery.

Based on the design that the edge of the second portion 1322 is adhered to and fixed to the electrical connection region 111 by the adhesive layer 140, in an embodiment of the utility model, the adhesive layer 140 may also be a conductive adhesive layer, and the conductive adhesive layer connects the active material layer 120 and the surface of the conductive extension member 130 facing away from the current collector 110. Through the design, the conductive function can be realized by utilizing the conductive adhesive layer, so that the overcurrent capacity between the conductive extension piece 130 and the active material layer 120 is further improved.

Based on the design that the edge of the second portion 1322 is adhered and fixed to the electrical connection region 111 through the adhesive layer 140, and the adhesive layer 140 is a conductive adhesive layer, in an embodiment of the present utility model, an insulating adhesive tape (not shown in the drawings) may be further disposed on the outer portion of the conductive adhesive layer. Through the design, the utility model can avoid the problem of short circuit of the battery caused by the lap joint of the conductive adhesive layer and the battery shell, and further ensure the safety of the battery.

Referring to fig. 9, there is representatively illustrated a partially enlarged schematic view of an electrode tab 100 in another exemplary embodiment of a battery capable of embodying principles of the present utility model in fig. 9, with reference to fig. 2 in particular to the enlarged area of fig. 1.

Unlike the embodiment shown in fig. 1 to 8, which employs a design in which the conductive extension member 130 includes one second connection portion, as shown in fig. 9, in an embodiment of the present utility model, the conductive extension member 130 may include two second connection portions, which are respectively connected to the first connection portions, and the two second connection portions are respectively welded to opposite surfaces of the electrical connection region 111 of the current collector 110 with respective first portions 1321.

In one embodiment of the present utility model, the battery provided by the present utility model may include a case having a plurality of walls that enclose a receiving cavity that receives the electrode tab 100. The electrode output terminal 200 is disposed on the housing, and a pressure relief structure, such as but not limited to an explosion-proof valve, is further disposed on the housing. On this basis, the electrode output terminal 200 and the pressure relief structure may be located on the same wall surface. With the above design, when thermal runaway occurs in the battery, the high-temperature substances in the case may accumulate toward the pressure release structure, and the high-temperature substances may also submerge the internal components closer to the explosion-proof valve, such as the electrical connection region 111 in the battery case to which the electrode output terminal 200 is connected. The temperature of the high-temperature substance is usually 600 ℃ or higher, and the electric connection region 111 having the base material layer (the material melting point of the base material layer is generally lower than 400 ℃) as a base material can be quickly fused, so that the electric connection of the battery in which thermal runaway occurs can be cut off from the inside, and the risk of further temperature rise and fire of the battery in which thermal runaway occurs can be reduced.

It should be noted herein that the batteries shown in the drawings and described in this specification are only a few examples of the wide variety of batteries that can employ the principles of the present utility model. It should be clearly understood that the principles of the present utility model are in no way limited to any details or any components of the battery shown in the drawings or described in this specification.

In summary, the electrode tab 100 of the battery according to the present utility model includes the current collector 110, the active material layer 120 and the conductive extension member 130, wherein the first end 131 of the conductive extension member 130 is connected to the electrode output terminal 200, the second end 132 of the conductive extension member 130 has a first portion 1321 and a second portion 1322, the first portion 1321 is welded to the electrical connection region 111 of the current collector 110 and forms the connection region 133, and the second portion 1322 is located on one side of the first portion 1321 near the active material layer 120. The second portion 1322 has a first length, and the distance between the end of the connection region 133 near the active material layer 120 and the active material layer 120 is a second length, and the ratio of the first length to the second length is 0.1-0.9. Through the design, the second part 1322 of the second end 132 of the conductive extension member 130 is prevented from being far away from the active material layer 120, so that the first part 1321 of the second end 132 and the electric connection region 111 of the current collector 110 are ensured to have enough welding area, the effective welding of the conductive extension member 130 and the current collector 110 is ensured, and the overcurrent requirement of the electrode plate 100 is met. Meanwhile, the utility model can avoid the second part 1322 from being too close to the active substance, thereby avoiding the second part 1322 from overlapping the active substance layer 120 due to factors such as processing tolerance, positioning error and the like in the assembly process, ensuring the flatness of a plurality of electrode slices 100 after overlapping, avoiding the occurrence of lithium precipitation of the negative electrode slices 100 and ensuring the electrical property of the battery.

Based on the above detailed description of several exemplary embodiments of the battery set forth in the present utility model, an exemplary embodiment of the battery device set forth in the present utility model will be described below.

In one embodiment of the present utility model, the battery device according to the present utility model includes the battery according to the present utility model and described in detail in the above embodiment.

In an embodiment of the present utility model, the battery device provided by the present utility model may be a battery pack. In some embodiments, the battery device provided by the utility model can also be a battery module.

It should be noted herein that the battery devices shown in the drawings and described in this specification are only a few examples of the wide variety of battery devices that can employ the principles of the present utility model. It should be clearly understood that the principles of the present utility model are in no way limited to any details or any components of the battery device shown in the drawings or described in this specification.

In summary, the battery device provided by the utility model can meet the overcurrent requirement of the electrode plate and ensure the electrical performance of the battery.

Exemplary embodiments of the battery and the battery device according to the present utility model are described and/or illustrated in detail above. Embodiments of the utility model are not limited to the specific embodiments described herein, but rather, components and/or steps of each embodiment may be utilized independently and separately from other components and/or steps described herein. Each component and/or each step of one embodiment may also be used in combination with other components and/or steps of other embodiments. When introducing elements/components/etc. that are described and/or illustrated herein, the terms "a," "an," and "the" are intended to mean that there are one or more of the elements/components/etc. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements/components/etc., in addition to the listed elements/components/etc. Furthermore, the terms "first" and "second" and the like in the claims and in the description are used for descriptive purposes only and not for numerical limitation of their subject matter.

While the utility model has been described in terms of various specific embodiments, those skilled in the art will recognize that the utility model can be practiced with modification within the spirit and scope of the claims.

Claims (12)

1. The battery is characterized by comprising an electrode pole piece and an electrode output terminal, wherein the electrode pole piece comprises a current collector, an active material layer and a conductive extension piece, the current collector comprises a substrate layer and two conductive layers, the two conductive layers are respectively arranged on two opposite surfaces of the substrate layer, the active material layer is arranged on a part of the surface of the current collector, the current collector is provided with an electric connection area, the electric connection area is positioned in the area of the current collector, which is not provided with the active material layer, the conductive extension piece is provided with a first end part and a second end part, the first end part is connected with the electrode output terminal, the second end part is overlapped with the electric connection area, the first part of the second end part is welded with the electric connection area to form a connection area, and the second part of the second end part is positioned on one side, which is close to the active material layer, of the first part; the length of the second portion is a first length along the extending direction of the electric connection area, the distance between one end of the connection area, which is close to the active material layer, and the active material layer is a second length, and the ratio of the first length to the second length is 0.1-0.9.

2. The battery according to claim 1, wherein a surface of a partial region of the current collector where the active material layer is provided is not parallel to a connection contact surface of the first end portion and the electrode output terminal, the electric connection region is bent in a thickness direction of the electrode tab, and the second end portion is located inside the electric connection region in the bending direction; wherein the ratio of the first length to the second length is 0.1-0.8.

3. The battery according to claim 1, wherein a surface of a partial region of the current collector where the active material layer is provided is not parallel to a connection contact surface of the first end portion and the electrode output terminal, the electric connection region is bent in a thickness direction of the electrode tab, and the second end portion is located outside the electric connection region in the bending direction; wherein the ratio of the first length to the second length is 0.1-0.8.

4. A battery according to claim 3, wherein the edge of the second portion of the second end portion is adhesively secured to the electrical connection region of the current collector via a glue line.

5. The battery of claim 4, wherein the ratio of the first length to the second length is 0.15 to 0.8.

6. The battery of claim 4, wherein the glue layer is an insulating glue layer.

7. The battery of claim 4, wherein the glue layer is a conductive glue layer that connects the active material layer and the surface of the conductive extension facing away from the current collector, respectively.

8. The battery of claim 7, wherein an insulating tape is disposed outside of the conductive adhesive layer.

9. The battery according to any one of claims 1 to 8, wherein the current collector comprises a base material layer and two conductive layers, the two conductive layers are respectively disposed on all areas of opposite surfaces of the base material layer, and the two active material layers are respectively disposed on surfaces of the two conductive layers facing away from the base material layer.

10. The battery of claim 9, wherein the conductive extension has two second ends, the two second ends being respectively connected to the first ends, the two second ends being respectively connected to the two conductive layers of the current collector at the electrical connection region; wherein the surface of a partial region of the current collector provided with the active material layer is not parallel to the connection contact surface of the first end portion and the electrode output terminal, the electric connection region is bent in the thickness direction of the electrode sheet, and the two second end portions are respectively positioned at the inner side and the outer side of the electric connection region in the bending direction; wherein, for any one of the second end portions, the ratio of the first length to the second length is 0.1 to 0.8.

11. The battery according to any one of claims 1 to 8, wherein the battery comprises a case having a plurality of wall surfaces, a plurality of the wall surfaces enclosing to form a housing chamber housing the electrode tab, the electrode output terminal is provided in the case, and a pressure release structure is provided on the case; wherein the electrode output terminal and the pressure relief structure are positioned on the same wall surface.

12. A battery device comprising the battery according to any one of claims 1 to 11.