CN220829980U - Composite pole piece, battery and electric equipment - Google Patents

Abstract

The utility model provides a composite pole piece, a battery and electric equipment, which comprises a current collector, wherein the current collector is provided with an active material area and a blank area, the blank area is positioned between the edge of the current collector and the active material area, and the blank area is at least arranged at the opposite ends of the current collector; the composite pole piece also comprises a diaphragm, wherein at least two opposite ends of the diaphragm are respectively fixed with the surfaces of the blank areas at least at two opposite ends of the current collector. According to the composite pole piece, the white area is arranged on the current collector, and the diaphragm is fixed with the surface of the white area, so that the diaphragm is fixed with the current collector, the diaphragm wrinkling is reduced, the diaphragm is not blocked, the battery performance is improved, and meanwhile, the manufacturing efficiency of the laminated battery core can be improved. The utility model also provides a battery and electric equipment.

Description

Composite pole piece, battery and electric equipment

Technical Field

The utility model relates to the technical field of batteries, in particular to a composite pole piece, a battery and electric equipment.

Background

The battery core of the lithium ion battery mainly comprises a winding battery core and a lamination battery core, wherein the lamination battery core has the advantages of fast electrolyte infiltration, strong heat dissipation capacity, high qualification rate of pole pieces and the like.

The phenomenon of diaphragm wrinkling often occurs in the traditional manufacturing process of the laminated battery cell. In order to reduce the wrinkling of the diaphragm, a bag making process (namely, a diaphragm bag with a bag-shaped structure is used as the diaphragm, a pole piece is arranged in the diaphragm bag) and/or a thermal compounding process (namely, an adhesive is arranged between the pole piece and the diaphragm and then the pole piece and the diaphragm are bonded by hot pressing) are commonly used in the lamination process at present, so that the diaphragm and the pole piece are attached and fixed as much as possible. However, the pole piece and the diaphragm bag in the bag making process are not fixed, and the pole piece can shake in the diaphragm bag, so that deviation of a lithium ion transmission path occurs; in the thermal compounding process, as the adhesive is arranged between the active material on the pole piece and the diaphragm, the diaphragm is blocked by the adhesive, thereby affecting the transmission of lithium ions and reducing the performance of the battery.

How to fix the pole piece and the diaphragm, avoid the diaphragm blocking, ensure the normal transmission function of lithium ions of the diaphragm, and improve the lamination efficiency as much as possible is a problem to be considered by the person skilled in the art.

Disclosure of utility model

The utility model aims to provide a composite pole piece, wherein a white area is arranged on a current collector, and a diaphragm is fixed with the surface of the white area, so that the diaphragm is fixed with the current collector, the wrinkling of the diaphragm is reduced, the diaphragm is not blocked, the battery performance is improved, and meanwhile, the manufacturing efficiency of a laminated battery core can be improved.

One embodiment of the utility model provides a composite pole piece, which comprises a current collector, wherein the current collector is provided with an active material area and a blank area, the blank area is positioned between the edge of the current collector and the active material area, and the blank area is at least arranged at two opposite ends of the current collector; the composite pole piece also comprises a diaphragm, wherein at least two opposite ends of the diaphragm are respectively fixed with the surfaces of the blank areas at least at two opposite ends of the current collector.

In one implementation, a composite trace is formed on the surface of the blank area at a position fixed with the diaphragm, and the composite trace is a continuous structure or a discontinuous structure.

In one possible manner, the separator is disposed at opposite sides of the current collector in a thickness direction of the current collector, and covers surfaces of the opposite sides of the current collector.

In one implementation, the membrane is a sheet-like structure; the separator is disposed on opposite sides of the current collector in a thickness direction of the current collector and is stacked with the current collector.

In one implementation, the separator is a separator pouch of pouch-like structure, and the current collector is located within the separator pouch.

In one implementation, the composite pole piece further includes a tab, the diaphragm not covering the tab.

In one possible implementation, the width of the blank area is D1, and D1 ranges from 0.5mm to 5mm, or from 0.5mm to 2mm.

In one implementation, a composite trace is formed on the surface of the blank area at a position fixed with the diaphragm, and the width of the composite trace is D2, and D2 is more than or equal to 0.5mm and less than or equal to D1.

In one possible manner, a composite trace is formed on the surface of the blank space at a position fixed to the separator, and a gap is formed between the composite trace and the active material region.

In one implementation, the current collector has a rectangular structure, the current collector has a length direction and a width direction, and the blank areas are arranged at opposite ends of the current collector along the width direction;

Or the blank areas are arranged at two opposite ends of the current collector along the length direction;

Or the blank areas are arranged at opposite ends of the current collector along the length direction and at one end along the width direction;

Or the blank area is arranged at the opposite ends of the current collector along the width direction and the opposite ends along the length direction, and the blank area is arranged around the periphery of the active material area in a circle.

In one implementation, the composite electrode sheet is a positive electrode sheet and/or a negative electrode sheet.

The utility model further provides a battery, which comprises a plurality of positive plates and a plurality of negative plates, wherein the positive plates and the negative plates are sequentially and alternately overlapped, and the positive plates and/or the negative plates are the composite plates.

Another embodiment of the present utility model further provides an electrical device, including the above battery.

According to the composite pole piece provided by the utility model, the white areas are arranged at least two opposite ends of the current collector, the active material layers are not arranged on the surfaces of the white areas, and at least two opposite ends of the diaphragm are respectively fixed with the surfaces of the white areas at least two opposite ends of the current collector, so that the diaphragm can be adhered and fixed with the current collector, the wrinkling of the diaphragm is further reduced, the diaphragm is not blocked, and the battery performance is improved. Meanwhile, as the diaphragm and the current collector are compounded together in advance in the composite pole piece, when the composite pole piece is overlapped to form the laminated battery cell, the lamination battery cell is not required to be overlapped with the diaphragm, and the composite pole piece and the pole piece with the polarity opposite to that of the lamination battery cell are directly overlapped, so that the manufacturing efficiency of the laminated battery cell is improved.

Drawings

Fig. 1 is a schematic plan view of a composite pole piece according to an embodiment of the present utility model.

Fig. 2 is a schematic cross-sectional view of fig. 1 at A-A.

Fig. 3 is a schematic diagram of the explosive structure of fig. 1.

Fig. 4 is a schematic plan view of the current collector of fig. 3.

Fig. 5 is a schematic plan view of a current collector according to another embodiment of the present utility model.

Fig. 6 is a schematic plan view of a current collector according to another embodiment of the present utility model.

Fig. 7 is a schematic plan view of a current collector according to another embodiment of the present utility model.

Fig. 8 is a schematic cross-sectional view of a composite pole piece in another embodiment of the utility model.

Fig. 9 is a schematic cross-sectional view of a composite pole piece in another embodiment of the utility model.

Fig. 10 is another cross-sectional schematic view of the composite pole piece of fig. 9.

Fig. 11 is a schematic plan view of a current collector according to another embodiment of the present utility model.

Fig. 12a to 12c are schematic views of a manufacturing process of a composite pole piece according to an embodiment of the present utility model.

Fig. 13a to 13c are schematic views illustrating a manufacturing process of a composite pole piece according to another embodiment of the present utility model.

In the figure: 1-current collector, 11-active material area, 12-blank area, 120-composite trace, 13-tab, 2-active material layer, 20-gap, 200-active material, 3-separator, 4-foil, 40-foil monomer, 41-coating area, 42-blank area.

Detailed Description

The following describes in further detail the embodiments of the present utility model with reference to the drawings and examples. The following examples are illustrative of the utility model and are not intended to limit the scope of the utility model.

The terms "first," "second," "third," "fourth" and the like in the description and in the claims, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order.

The terms upper, lower, left, right, front, rear, top, bottom and the like (if any) in the description and in the claims are used for descriptive purposes and not necessarily for describing relative positions of structures in the figures and in describing relative positions of structures. It should be understood that the use of directional terms should not be construed to limit the scope of the utility model as claimed.

As shown in fig. 1 to 4, the composite pole piece provided by the embodiment of the utility model comprises a current collector 1, wherein an active material region 11 and a blank region 12 are arranged on the current collector 1. The blank area 12 is located between the edges of the current collector 1 (i.e., the sides of the current collector 1) and the active material area 11, i.e., the blank area 12 is disposed at the edge of the current collector 1, and the blank area 12 is disposed at least at two opposite ends of the current collector 1 (i.e., the blank area 12 is disposed at least between the edges of two opposite sides of the current collector 1 and the active material area 11). In the thickness direction T of the current collector 1, the active material layer 2 is provided on the surface of the active material region 11, and the active material layer 2 is not provided on the surface of the blank region 12. The composite pole piece further comprises a diaphragm 3, the diaphragm 3 is attached to the surface of the current collector 1, and at least two opposite ends of the diaphragm 3 are respectively fixed to the surfaces of the blank areas 12 at least at two opposite ends of the current collector 1.

Specifically, the composite pole piece provided in this embodiment, by disposing the blank area 12 at least two opposite ends of the current collector 1, the active material layer 2 is not disposed on the surface of the blank area 12, and at least two opposite ends of the separator 3 are respectively fixed with the surfaces of the blank area 12 at least two opposite ends of the current collector 1, so that the separator 3 can be adhered and fixed with the current collector 1, further, wrinkling of the separator 3 is reduced, and blocking of the separator 3 is not caused, thereby improving battery performance. Meanwhile, as the diaphragm 3 and the current collector 1 in the composite pole piece are compounded together in advance, when the composite pole piece is overlapped to form the laminated battery cell, the lamination battery cell is not required to be overlapped with the diaphragm, and the composite pole piece and the pole piece with the polarity opposite to that of the lamination battery cell are directly overlapped, so that the manufacturing efficiency of the laminated battery cell is improved.

As shown in fig. 1 to 3, as an embodiment, the diaphragm 3 is a sheet-like structure (i.e., the diaphragm 3 is a diaphragm sheet); the separator 3 is provided on at least one side of the current collector 1 in the thickness direction T of the current collector 1 and is laminated with the current collector 1.

As shown in fig. 1 to 3, as an embodiment, the separator 3 is disposed at least on the side of the current collector 1 provided with the active material layer 2, so that the separator 3 not only has a good insulating and blocking effect, but also has a protective effect on the active material layer 2, and reduces or prevents the active material layer 2 on the current collector 1 from falling off.

As shown in fig. 2, as an embodiment, an active material layer 2 is provided on the surface of the active material region 11 side, and a separator 3 is provided on the side of the current collector 1 where the active material layer 2 is provided, in the thickness direction T of the current collector 1. As another embodiment, the active material layer 2 is provided on the surface of the active material region 11 on one side, and the separator 3 is provided on opposite sides of the current collector 1 (i.e., the separator 3 is also provided on the side of the current collector 1 on which the active material layer 2 is not provided) in the thickness direction T of the current collector 1, and the separators 3 on the opposite sides are respectively fixed to the surfaces of the opposite sides of the blank region 12.

As another embodiment, the active material layer 2 is provided on the surfaces of the opposite sides of the active material region 11, and the separator 3 is provided on one side (either side) of the current collector 1 in the thickness direction T of the current collector 1.

As another embodiment, as shown in fig. 8, active material layers 2 are provided on the surfaces of the opposite sides of the active material region 11, and separators 3 are provided on the opposite sides of the current collector 1 in the thickness direction T of the current collector 1, the separators 3 on the opposite sides being fixed to the surfaces of the opposite sides of the white space 12, respectively.

As shown in fig. 9 and 10, as another embodiment, the separator 3 is a separator bag with a bag-shaped structure, the current collector 1 is located in the separator bag (i.e., the current collector 1 is wrapped by the separator bag), and the separator bag can be obtained by a bag-making process from the separator; the inner wall of the diaphragm bag is fixed to the surface of the blank area 12.

As shown in fig. 1 to 4, as an embodiment, the composite pole piece further includes a pole tab 13, where the pole tab 13 is connected to the white space 12 (specifically, the pole tab 13 and the white space 12 may be an integral structure; of course, the pole tab 13 may also be connected to the active material region 11); in the thickness direction T of the current collector 1, the separator 3 is disposed on one side of the current collector 1, the separator 3 completely covers the surface of one side of the current collector 1, and the separator 3 does not cover the tab 13 (i.e., the tab 13 protrudes out of the coverage of the separator 3). As another embodiment, the separator 3 is provided at opposite sides of the current collector 1 in the thickness direction T of the current collector 1, the separator 3 completely covers the surfaces of the opposite sides of the current collector 1, and the separator 3 does not cover the tab 13.

Specifically, when the separator 3 is in the sheet structure shown in fig. 1, the length and width dimensions of the separator 3 may be greater than or equal to the length and width dimensions of the current collector 1, respectively, at which time the separator 3 can completely cover the surface of the current collector 1 (when the separator 3 is disposed on one side of the current collector 1, the separator 3 covers the surface of one side of the current collector 1; when the separator 3 is disposed on the opposite sides of the current collector 1, the separator 3 covers the surfaces of the opposite sides of the current collector 1), and the separator 3 does not cover the tab 13. When the separator 3 has a pouch-like structure as shown in fig. 9, the current collector 1 is positioned in the separator pouch, and the separator pouch covers the surfaces of the opposite sides of the current collector 1, and the tab 13 protrudes out of the separator pouch.

As shown in fig. 3 and 4, as one embodiment, the current collector 1 and the separator 3 each have a rectangular structure, and the current collector 1 has a longitudinal direction L and a width direction W. The blank areas 12 are arranged at the opposite ends of the current collector 1 along the width direction W and the opposite ends of the current collector 1 along the length direction L, the blank areas 12 are arranged around the periphery of the active material area 11 in a circle, namely the blank areas 12 are arranged at the peripheral edge positions of the current collector 1, and the lugs 13 are connected with the blank areas 12 at one end of the blank areas; at this time, the peripheral edge positions of the separator 3 may be fixed to the blank areas 12 of the peripheral edges of the current collector 1, respectively. Of course, the opposite ends of the separator 3 may be respectively fixed to the blank areas 12 at the opposite ends of the current collector 1, or the adjacent three ends of the separator 3 may be respectively fixed to the blank areas 12 at the adjacent three ends of the current collector 1.

As shown in fig. 5, as another embodiment, the white space 12 is provided at opposite ends of the current collector 1 in the length direction L and at one end in the width direction W (i.e., the white space 12 is provided at the adjacent three ends of the current collector 1), and the tab 13 is connected to the white space 12 at one end of the current collector 1 in the width direction W; at this time, the adjacent three ends of the separator 3 are respectively fixed with the blank area 12 of the adjacent three ends of the current collector 1. Of course, the opposite ends of the separator 3 may be fixed to the blank areas 12 at the opposite ends of the current collector 1, respectively.

As another embodiment, as shown in fig. 6, the white regions 12 are provided at opposite ends of the current collector 1 in the width direction W, the tabs 13 are connected to the white regions 12 at one end thereof, and the opposite ends of the separator 3 are fixed to the white regions 12 at the opposite ends of the current collector 1, respectively.

As another embodiment, as shown in fig. 7, the white-reserving sections 12 are provided at opposite ends of the current collector 1 in the length direction L, the tabs 13 are connected to the white-reserving sections 12 at one end thereof, and the opposite ends of the separator 3 are fixed to the white-reserving sections 12 at the opposite ends of the current collector 1, respectively.

As shown in fig. 2 to 4, as an embodiment, the surface of the membrane 3 and the blank 12 may be compositely fixed by means of an adhesive (for example, adhesive bonding between the membrane 3 and the surface of the blank 12 at normal temperature), thermal compression bonding (i.e., adhesive bonding between the membrane 3 and the surface of the blank 12 after adhesive bonding), thermal fusion bonding (i.e., melting of the membrane 3 after heating and bonding with the surface of the blank 12), ultrasonic welding, or the like, and a composite trace 120 is formed on the surface of the blank 12 at a position where the membrane 3 is fixed (i.e., a trace (similar to a weld mark) is formed on the surface of the blank 12 when the surface of the blank 12 is fixed with the membrane 3; the trace may be an adhesive trace or the like according to the difference of the composite mode), and the composite trace 120 and the active material 11 have a gap 20 therebetween (i.e., a gap between the connection position of the blank 12 and the membrane 3 and the active material region 11), so as to avoid falling of the active material due to contact with the active material layer 2 during compositing.

As shown in fig. 4, as an embodiment, the composite trace 120 is a continuous structure (i.e., a continuous structure). Of course, as shown in fig. 11, as another embodiment, the compound trace 120 may be a discontinuous structure (i.e., a discontinuous structure).

As shown in fig. 4, as an embodiment, the width of the blank area 12 is D1, and D1 ranges from 0.5mm to 5mm; or 0.5mm to 3mm; or 0.5mm to 2mm; or 0.5mm to 1.5mm; or 0.8mm to 1.3mm; or 1mm.

As shown in FIG. 4, as one embodiment, the width of the composite trace 120 is D2,0.5mm < D2 < D1.

As an embodiment, the composite electrode sheet is a positive electrode sheet (i.e., a composite positive electrode sheet) and/or a negative electrode sheet (i.e., a composite negative electrode sheet).

As shown in fig. 4 and fig. 12a to 12c, the embodiment of the utility model further provides a method for manufacturing a composite pole piece, which comprises the following steps:

S1: providing a foil unit 40, wherein the foil unit 40 comprises a coating area 41 and an empty foil area 42, and the surface of the coating area 41 is coated with an active substance 200;

S2: compounding the empty foil area 42 of the foil unit 40 with the membrane 3;

s3: cutting the empty foil area 42 of the foil unit 40 and the diaphragm 3 to obtain a composite pole piece; the blank foil area 42 of the foil unit 40 forms the blank area 12 of the current collector 1 after cutting, the coating area 41 of the foil unit 40 is the active material area 11 of the current collector 1, and the active material 200 on the surface of the coating area 41 is the active material layer 2 on the surface of the active material area 11.

In one embodiment, in the step S1, the foil unit 40 is a copper foil or an aluminum foil.

In one embodiment, in the step S1, the tab is formed on the foil member 40 in advance by cutting, so that in the step S3, the tab is not required to be formed by cutting the foil member 40.

As shown in fig. 12a to 12c, as an embodiment, the step S1 specifically includes:

S11: as shown in fig. 12a, a strip-shaped foil 4 is provided, a plurality of coating areas 41 are arranged on the foil 4 at intervals along the length direction of the foil, and empty foil areas 42 are positioned at the periphery of each coating area 41 (namely, the empty foil areas 42 are positioned between adjacent coating areas 41 and between the coating areas 41 and two side edges of the foil 4);

s12: as shown in fig. 12b, the active material 200 is coated on the surface of each coating area 41 of the foil 4, and then the empty foil area 42 of the foil 4 is cut (i.e. along the cutting line S1 in fig. 12 b), so as to obtain a plurality of foil units 40 as shown in fig. 12c, wherein the empty foil area 42 is formed around the coating area 41 of the foil unit 40.

Then, the foil material monomer 40 is subjected to membrane compounding in the step S2 and cutting in the step S3. In this way, a composite pole piece having the current collector 1 shown in fig. 4 can be manufactured.

Of course, in other embodiments, in the step S12, the blank foil area 42 of the foil 4 may be cut in other manners to obtain a plurality of foil units 40, where the blank foil area 42 is formed at three sides of the coating area 41 of the foil unit 40 (i.e. the blank foil area 42 is disposed at three adjacent ends of the foil unit 40); then, the foil material monomer 40 is subjected to membrane compounding in the step S2 and cutting in the step S3. In this way, a composite pole piece having the current collector 1 shown in fig. 5 can be manufactured.

In the above two modes, the empty foil area 42 of the foil 4 is cut, so that the active material 200 is prevented from being cut, and dust caused by falling of the active material 200 is reduced.

As shown in fig. 13a to 13c, as another embodiment, the step S1 specifically includes:

S11: as shown in fig. 13a, an elongated foil 4 is provided, and a coating area 41 is continuously arranged along the length direction of the foil 4, and empty foil areas 42 are positioned at two sides of the coating area 41 (i.e. the empty foil areas 42 are positioned between the coating area 41 and two sides of the foil 4);

S12: as shown in fig. 13b, the active material 200 is coated on the surface of the coating area 41 of the foil 4, and then the coating area 41 and the empty foil area 42 of the foil 4 are cut (i.e., along the cutting line S2 in fig. 13 b), so as to obtain a plurality of foil units 40 as shown in fig. 13c, wherein the empty foil areas 42 are formed on opposite sides of the coating area 41 of the foil units 40.

Then, the foil material monomer 40 is subjected to membrane compounding in the step S2 and cutting in the step S3. In this way, a composite pole piece having the current collector 1 as shown in fig. 6 or 7 can be manufactured. Since this method requires cutting the coating region 41, the active material 200 is cut, and a part of the active material 200 is peeled off.

In one embodiment, in the step S2, the empty foil area 42 of the foil member 40 and the separator 3 may be combined by adhesive bonding, thermocompression bonding, hot melt bonding, ultrasonic welding, or the like.

The embodiment of the utility model also provides a battery, in particular to a laminated battery, which comprises a plurality of positive plates and a plurality of negative plates, wherein the positive plates and the negative plates are sequentially and alternately overlapped, and the positive plates and/or the negative plates are the composite plates.

The embodiment of the utility model also provides electric equipment, such as an electric vehicle, energy storage equipment and the like, comprising the battery.

According to the composite pole piece provided by the embodiment of the utility model, the white-keeping areas 12 are arranged at least two opposite ends of the current collector 1, the active material layer 2 is not arranged on the surfaces of the white-keeping areas 12, and at least two opposite ends of the diaphragm 3 are respectively fixed with the surfaces of the white-keeping areas 12 at least two opposite ends of the current collector 1, so that the diaphragm 3 can be adhered and fixed with the current collector 1, the wrinkling of the diaphragm 3 is reduced, the diaphragm 3 is not blocked, and the battery performance is improved. Meanwhile, as the diaphragm 3 and the current collector 1 in the composite pole piece are compounded together in advance, when the composite pole piece is overlapped to form the laminated battery cell, the lamination battery cell is not required to be overlapped with the diaphragm, and the composite pole piece and the pole piece with the polarity opposite to that of the lamination battery cell are directly overlapped, so that the manufacturing efficiency of the laminated battery cell is improved.

Examples

Preparing a composite negative plate: a coating area and a blank area are defined on the copper foil, the blank area is positioned between the periphery of the coating area and the edge of the copper foil, and the width of the blank area is 1mm; a negative electrode active material is coated on the surface of the coated region of the copper foil to form an active material layer. And compounding the blank area of the copper foil with the diaphragm, and then cutting the blank area of the copper foil and the diaphragm to align the edge of the diaphragm with the edge of the copper foil, wherein the diaphragm completely covers the copper foil at the moment to obtain the composite negative plate.

The composite mode of the blank area of the copper foil and the diaphragm can be as follows:

Diaphragm compound mode one: and (3) coating an adhesive with the width of 0.5mm on the periphery of the blank area far away from the active material layer, and bonding and fixing the flattened diaphragm and the blank area through the adhesive.

And a diaphragm compounding mode II: and (3) carrying out hot melting compounding on the flattened diaphragm and the blank area of the copper foil by a heating ironing head at the periphery of the blank area far away from the active material layer, wherein the compounding trace is 0.5mm.

And a diaphragm compounding mode III: and compounding the flattened diaphragm and the blank area of the copper foil by an ultrasonic welding head at the periphery of the blank area far away from the active material layer, wherein the compounding trace is 0.5mm.

Laminating the prepared composite negative plate and positive plate (the lugs of the positive plate are coated with ceramic layers) in a stacking mode to obtain a plate group; and then wrapping the laminated pole piece group by using a PET film for packaging, and obtaining the laminated battery cell after liquid injection.

The foregoing is merely illustrative embodiments of the present utility model, but the scope of the present utility model is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the technical scope of the present utility model, and the utility model should be covered. Therefore, the protection scope of the utility model is subject to the protection scope of the claims.

Claims (13)

1. A composite pole piece comprising a current collector (1), characterized in that the current collector (1) is provided with an active material region (11) and a blank region (12), the blank region (12) is located between the edge of the current collector (1) and the active material region (11), and the blank region (12) is at least arranged at opposite ends of the current collector (1); the composite pole piece further comprises a diaphragm (3), and at least two opposite ends of the diaphragm (3) are respectively fixed with the surfaces of the blank areas (12) at least at two opposite ends of the current collector (1).

2. A composite pole piece according to claim 1, characterized in that a composite trace (120) is formed on the surface of the blank area (12) at a position fixed to the diaphragm (3), the composite trace (120) being of a continuous or discontinuous structure.

3. A composite pole piece according to claim 1, wherein the separator (3) is provided on opposite sides of the current collector (1) in the thickness direction (T) of the current collector (1), and the separator (3) covers surfaces of the opposite sides of the current collector (1).

4. A composite pole piece according to claim 3, wherein the membrane (3) is of sheet-like construction; the separator (3) is disposed on opposite sides of the current collector (1) in the thickness direction (T) of the current collector (1) and is laminated with the current collector (1).

5. A composite pole piece according to claim 3, characterized in that the separator (3) is a separator pouch of pouch-like structure, the current collector (1) being located within the separator pouch.

6. The composite pole piece according to claim 1, further comprising a tab (13), the diaphragm (3) not covering the tab (13).

7. A composite pole piece according to claim 1, wherein the width of the blank area (12) is D1, D1 being in the range of 0.5mm to 5mm.

8. The composite pole piece of claim 7, wherein a composite trace (120) is formed on the surface of the blank area (12) at a position fixed with the diaphragm (3), and the width of the composite trace (120) is D2, D2 is more than or equal to 0.5mm and less than or equal to D1.

9. A composite pole piece according to claim 1, characterized in that a composite trace (120) is formed on the surface of the blank area (12) at a position fixed to the separator (3), the composite trace (120) and the active substance area (11) having a gap (20) therebetween.

10. The composite pole piece according to any one of claims 1 to 9, wherein the current collector (1) has a rectangular structure, the current collector (1) having a length direction (L) and a width direction (W), the blank areas (12) being disposed at opposite ends of the current collector (1) in the width direction (W);

Or the blank areas (12) are arranged at opposite ends of the current collector (1) along the length direction (L);

Or the blank area (12) is arranged at opposite ends of the current collector (1) along the length direction (L) and at one end along the width direction (W);

Or the blank area (12) is arranged at the opposite ends of the current collector (1) along the width direction (W) and the opposite ends along the length direction (L), and the blank area (12) is arranged around the periphery of the active material area (11) in a circle.

11. The composite pole piece of any of claims 1-9, wherein the composite pole piece is a positive pole piece and/or a negative pole piece.

12. A battery comprising a plurality of positive plates and a plurality of negative plates, wherein a plurality of the positive plates and a plurality of the negative plates are sequentially and alternately stacked, and the battery is characterized in that the positive plates and/or the negative plates are the composite plates according to any one of claims 1-11.

13. A powered device comprising the battery of claim 12.