CN113594466B

CN113594466B - Current collector, battery core and electricity utilization device

Info

Publication number: CN113594466B
Application number: CN202110758263.9A
Authority: CN
Inventors: 汪慧明
Original assignee: Dongguan Poweramp Technology Ltd
Current assignee: Dongguan Poweramp Technology Ltd
Priority date: 2021-07-05
Filing date: 2021-07-05
Publication date: 2023-07-28
Anticipated expiration: 2041-07-05
Also published as: CN113594466A

Abstract

The embodiment of the application relates to the technical field of batteries and discloses a current collector, an electric core and an electric device. The battery cell comprises a pole piece, wherein the pole piece comprises a current collector. The current collector comprises a foil layer and a conductive material layer; the foil layer has a major surface defined by a length and a width of the foil layer, and the layer of conductive material is disposed on the major surface. The conductive material layer comprises a conductive layer, the conductive layer comprises more than one conductive material, and the standard electrode potential of at least one conductive material in the conductive layer is larger than the standard electrode potential of the foil layer. The active material layer is arranged on one side of the conductive material layer, which is away from the foil layer. The battery cell can improve the current situation that the surface of the pole piece of the current battery cell is likely to separate out metal simple substances in the charging and discharging process.

Description

Current collector, battery core and electricity utilization device

[ field of technology ]

The embodiment of the application relates to the technical field of batteries, in particular to a current collector, an electric core and an electric device.

[ background Art ]

A battery cell is a device that converts external energy into electric energy and stores the electric energy therein to supply power to external devices (e.g., portable electronic devices) at a desired time. At present, the battery cell is widely applied to electronic products such as mobile phones, flat plates, notebook computers and the like.

Generally, the battery cell includes a case, an electrode assembly, a tab, and an electrolyte filled in the case. The electrode assembly comprises a cathode plate, an anode plate and a separation film arranged between the cathode plate and the anode plate. The pole piece (the anode piece or the cathode piece) comprises a current collector and an active material layer coated on the current collector; wherein the current collector is a metal foil such as copper foil or aluminum foil.

When the battery cell is over-discharged or reversely charged, the current collector of the anode sheet is partially oxidized and dissolved in the process; when the battery core is fully charged again, metal simple substances (such as copper simple substances) can be separated out from the surface of the anode sheet; this may lead to internal shorting of the cells, which may in turn cause safety accidents. Of course, the factor of precipitation of the metal element on the surface of the anode sheet is not limited thereto, and it may be caused by a charging process after long-time storage or the like. In addition, in some cases, the current collector in the cathode sheet may be dissolved, so that a metal simple substance is separated out from the surface of the cathode sheet in the process of charging and discharging the battery cell.

[ invention ]

The embodiment of the application aims to provide a current collector, a battery cell and an electricity utilization device, so as to improve the current situation that the surface of a pole piece of the current battery cell is likely to separate out a metal simple substance in the charging and discharging process.

The technical scheme adopted for solving the technical problems in the embodiment of the application is as follows:

an electrical cell includes a pole piece including a current collector and an active material layer. The current collector comprises a foil layer and a conductive material layer; the foil layer has a major surface defined by a length and a width of the foil layer, and the layer of conductive material is disposed on the major surface. The conductive material layer comprises a conductive layer, the conductive layer comprises more than one conductive material, and the standard electrode potential of at least one conductive material in the conductive layer is larger than the standard electrode potential of the foil layer. The active material layer is arranged on one side of the conductive material layer, which is away from the foil layer.

In the area of the foil layer covered by the conductive material higher than the standard electrode potential in the conductive layer, even if the potential at the pole piece is slightly higher than that of the foil layer, the foil layer is partially oxidized to be in an ionic state, but due to the arrangement of the conductive material layer, the conductive layer can prevent the ions from dissociating to the surface of the pole piece in a physical isolation mode, so that the metal simple substance of the foil layer is prevented from being separated out from the surface of the pole piece in the battery cell. In addition, as the standard electrode potential of at least one conductive material in the conductive layer is greater than that of the foil layer, the conductive material above the standard electrode potential of the foil layer is not easy to oxidize before the potential rises to the point that the foil layer is completely oxidized and dissolved; that is, the conductive material layer of the current collector is not easy to oxidize, so that simple substance is separated out in the charge and discharge process. In summary, the battery cell provided by the embodiment of the application can improve the current situation that the metal element may be separated out from the surface of the pole piece in the charging and discharging process of the current battery cell.

As a further improvement of the above, the at least one conductive material includes at least one of silver, platinum, and gold.

As a further improvement of the above, the conductive material layer further includes a conductive base material layer. The conductive substrate layer is arranged on the main surface, and the conductive layer is arranged on one side, away from the foil layer, of the conductive substrate layer. The bonding force between the conductive substrate layer and the conductive layer is larger than a preset threshold, the bonding force between the conductive substrate layer and the foil layer is larger than the preset threshold, and the preset threshold is the bonding force value of the conductive layer and the foil layer in direct bonding.

As a further improvement of the above, the conductive substrate layer includes at least one of a carbon nanocarbon layer, a carbon nanotube, and a conductive carbon black.

As a further improvement of the above, the thickness of the foil layer is 3 μm to 20 μm, the thickness of the conductive layer is 0.2 μm to 20 μm, and the thickness of the conductive base material layer is 0.2 μm to 2 μm.

As a further improvement of the above solution, the foil layer has two opposite main surfaces, both of which are provided with the conductive material layer.

As a further improvement of the above solution, in the extending direction of the broad side of the current collector, two ends of the conductive layer respectively exceed two ends corresponding to the active material layer by a distance greater than 0.5mm.

As a further improvement of the above, in the extending direction of the long side of the current collector, both ends of the conductive layer respectively exceed both ends of the active material layer.

Another embodiment of the present application also provides a current collector including a foil layer having a major surface defined by a length and a width of the foil layer. The current collector also includes a layer of conductive material disposed on the major surface. The conductive material layer comprises a conductive layer, the conductive layer comprises at least one conductive material, and the standard electrode potential of at least one conductive material in the conductive layer is greater than the standard electrode potential of the foil layer.

As a further improvement of the above, the conductive material layer further includes a conductive base material layer. The conductive substrate layer is arranged on the main surface, and the roughness of one side of the conductive substrate layer, which is away from the foil layer, is larger than that of the foil layer; the conductive layer is arranged on one side of the conductive substrate layer, which is away from the foil layer.

The other embodiment of the application also provides an electric device which comprises any one of the electric cores.

[ description of the drawings ]

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which the figures of the drawings are not to scale, unless expressly stated otherwise.

FIG. 1 is a top view of a pole piece according to one embodiment of the present disclosure in a flat state;

FIG. 2 is a front view of the pole piece of FIG. 1;

FIG. 3 is a top view of a pole piece according to another embodiment of the present application in a flat state;

FIG. 4 is a front view of the pole piece of FIG. 3;

FIG. 5 is a schematic diagram of a battery cell according to one embodiment of the present disclosure;

fig. 6 is a schematic diagram of an electrical device according to an embodiment of the present application.

In the figure:

100. a pole piece;

110. a current collector; 111. a foil layer; 112. a conductive material layer; 1121. a conductive layer; 1122. a conductive substrate layer; 101. a major surface; 1011. a long side; 1012. a broadside; 1013. a thickness edge;

120. an active material layer;

100b, pole pieces;

110b, a current collector; 111b, foil layers; 112b, a layer of conductive material; 1121b, a conductive layer; 1122b, a conductive substrate layer; 101b, major surface;

120b, an active material layer;

1. a battery cell;

2. and (5) an electric device.

[ detailed description ] of the invention

In order to facilitate an understanding of the present application, the present application will be described in more detail below with reference to the accompanying drawings and specific examples. It will be understood that when an element is referred to as being "fixed" to "/" affixed "to" another element, it can be directly on the other element or one or more intervening elements may be present therebetween. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or one or more intervening elements may be present therebetween. The terms "vertical," "horizontal," "left," "right," "inner," "outer," and the like are used in this specification for purposes of illustration only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used in this specification includes any and all combinations of one or more of the associated listed items.

In addition, the technical features described below in the different embodiments of the present application may be combined with each other as long as they do not collide with each other.

In this specification, the term "mounting" includes welding, screwing, clamping, adhering, etc. to fix or limit a certain element or device to a specific position or place, where the element or device may be fixed or limited to be removable or not removable, and the embodiment of the present application is not limited thereto.

Referring to fig. 1 and fig. 2, a top view and a front view of a pole piece 100 according to one embodiment of the present disclosure when being unfolded in a flat state are shown, where the pole piece 100 includes a current collector 110 and an active material layer 120. Wherein the current collector 110 comprises a foil layer 111 and a conductive material layer 112. The foil layer 111 has a major surface 101 defined by the length and width of the foil layer 111. The conductive material layer 112 is disposed on the main surface 101 and includes a conductive layer 1121, the conductive layer 1121 includes more than one conductive material, and a standard electrode potential of at least one conductive material in the conductive layer 1121 is greater than a standard electrode potential of the foil layer 111. Next, a specific structure of the pole piece 100 will be described by taking the pole piece 100 as an example of an anode piece in the battery cell; it should be understood that in other embodiments of the present application, the electrode sheet 100 may also be applied as a cathode sheet in a battery cell, and of course, the materials used when the electrode sheet 100 is applied as a cathode sheet and when it is applied as an anode sheet may be different.

For the current collector 110, please combine fig. 1 and fig. 2, the current collector 110 specifically includes a foil layer 111 and a conductive material layer 112. The foil layer 111 is a substrate of the current collector 110, and the conductive material layer 112 and the active material layer 120 are directly or indirectly attached to the foil layer 111. The foil layer 111 has a flat strip-like structure as a whole, and the thickness of each part is basically uniform, and the thickness is between 3 micrometers and 20 micrometers (mum). In this embodiment, the pole piece 100 is an anode piece, and the foil layer 111 includes copper foil; it is understood that in other embodiments of the present application, the foil layer 111 may be any foil applicable to the pole piece, such as stainless steel foil, aluminum foil, nickel platinum, etc., without being limited to the pole piece 100 being applied as an anode piece. Foil layer 111 has a long side 1011, a wide side 1012, and a thick side 1013; the long side 1011 is a side extending in the longitudinal direction of the current collector 110 when the current collector 110 is in a flat state, the wide side 1012 is a side extending in the width direction of the current collector 110 when the current collector 110 is in a flat state, and the thick side 1013 is a side extending in the thickness direction of the current collector 110 when the current collector is in a flat state. The foil layer 111 has two main surfaces 101, the main surfaces 101 being defined by the long side 1011 and the wide side 1012, and the two main surfaces 101 being arranged opposite to each other along the extending direction of the thickness side 1013.

The conductive material layer 112 is disposed on the main surface 101, and in this embodiment, the conductive material layer 112 is disposed on both main surfaces 101; of course, in other embodiments, only one main surface 101 may be provided with the conductive material layer 112. Specifically, the conductive material layer 112 includes a conductive layer 1121, and the conductive layer 1121 is disposed on the main surface 101 and covers at least a portion of the main surface 101; the conductive layer comprises more than one conductive material, and the standard electrode potential of at least one conductive material in the conductive layer 1121 is greater than the standard electrode potential of the foil layer 111. In this embodiment, the at least one conductive material includes platinum, and the conductive layer 1121 is entirely made of platinum and covers at least part of the main surface 101 by plating, coating, or the like. The thickness of the conductive layer 1121 is between 0.2 μm and 20 μm, so that the foil layer 111 is prevented from being partially exposed by the covered region due to the too thin thickness, and the energy density of the battery cell is prevented from being influenced due to the too large thickness. In the area where the foil layer 111 is covered by the conductive layer 1121, even if the potential at the pole piece is slightly higher than that of the foil layer, the foil layer is partially oxidized to form copper ions, which will not be dissociated to the surface of the current collector 110 and not to the surface of the active material layer 120 under the physical barrier of the conductive layer 1121; therefore, even if the copper ions in the above region have a tendency to precipitate copper simple substance during the charging process after the battery cell is over-discharged (or reversely charged), the copper simple substance will not precipitate on the surface of the current collector 110 or the surface of the active material layer 120, but between the conductive layer 1121 and the foil layer 111. Meanwhile, the standard electrode potential of the platinum is higher than that of the copper, so that the platinum is not easy to oxidize before the copper foil is completely oxidized and dissolved; therefore, the conductive layer 1121 is not easy to precipitate the platinum simple substance on the surface of the pole piece 100 in the charging process of the current collector 110 after the battery cell is over-discharged (or reversely charged). In summary, at the portion covered by the conductive layer 1121, the probability of separating out the simple substance of copper and the simple substance of platinum in the process of charging and discharging the battery cell by the pole piece 100 is low. Preferably, the conductive layer 1121 completely covers the foil layer 111; thus, the metal element is not easy to be separated out from the positions of the outer surface of the pole piece 100 corresponding to the main surface 101.

It will be appreciated that, even though the conductive layer 1121 includes only platinum in the present embodiment, the application is not limited thereto, as long as the standard electrode potential of at least one conductive material in the conductive layer 1121 is higher than that of the foil layer 111 and covers at least a portion of the main surface 101, so that the hidden danger of precipitation of metal elements on the surface of the pole piece 100 can be reduced. For example, in other embodiments of the present application, the conductive layer 1121 comprises silver. For another example, in other embodiments of the present application, the conductive layer 1121 includes gold. For example, in still other embodiments of the present application, the conductive layer 1121 comprises at least two of silver, platinum, and gold; the distribution of the different metals in the conductive layer 1121 is not particularly limited, and one of the above-mentioned silver, platinum, and gold may cover one region of the main surface 101, the other one covers another region of the main surface 101, or the above-mentioned silver, platinum, and gold may be uniformly distributed on each portion of the main surface 101 after being mixed. It should be noted that when the conductive layer 1121 is an alloy including a plurality of materials, it is preferable that the standard electrode potential of each material is higher than that of the foil layer 111.

It should be understood that even though the conductive material layer 112 in the present embodiment includes only the conductive layer 1121, the conductive layer 1121 is directly attached to the main surface 101 to cover at least a portion of the main surface 101, the present application is not limited thereto, but only by ensuring that the conductive material layer 112 includes the conductive layer 1121 described above. For example, fig. 3 and 4 show a top view and a front view, respectively, of a pole piece 100b according to another embodiment of the present application when the pole piece 100b is unfolded to be in a flat state, where the pole piece 100b includes a current collector 110b and an active material layer 120b; the current collector 110b includes a foil layer 111b and a conductive material layer 112b. The pole piece 100b differs from the pole piece 100 of the previous embodiment primarily in that the conductive material layer 112b of the pole piece 100b includes another conductive substrate layer 1122b in addition to the conductive layer 1121 b. Specifically, the conductive base material layer 1122b is provided on the main surface 101, and is made of a conductive material; in this embodiment, the conductive substrate layer 1122b includes a nanocarbon layer formed by mixing at least nanocarbon and an adhesive; it will be appreciated that in other embodiments of the present application, the conductive substrate layer 1122b is also other materials; for example, in some embodiments, the conductive substrate layer 1122b may include carbon nanotubes, or conductive carbon black, or other materials including at least two of the foregoing carbon nanolayers, carbon nanotubes, and conductive carbon black. The conductive layer 1121b is disposed on a side of the conductive substrate layer 1122b facing away from the foil layer 111 b. That is, the conductive layer 1121b indirectly covers at least part of the main surface 101 by being attached to the conductive base material layer 1122b. Preferably, the conductive substrate layer 1122b is configured to: the adhesion between the conductive substrate layer 1122b and the conductive layer 1121b is greater than a predetermined threshold, and the adhesion between the conductive substrate layer 1122b and the foil layer 111b is greater than the predetermined threshold; the preset threshold value is an adhesion force value of the conductive layer 1121b and the foil layer 111b when directly adhered. When the conductive layer 1121b includes only metal, the adhesion between it and the foil layer 111b is generally small, so there is a risk of falling off during use of the conductive layer cell; the above arrangement is advantageous in reducing the risk of the conductive layer 1121b falling off when directly coated on the foil layer 111 b. It should be noted that even when the present document defines the "preset threshold", a description is introduced that the conductive layer 1121b is directly bonded to the foil layer 111 b; it should be understood that the conductive layer 1121b is not actually in direct contact with the foil layer 111b, and the above description is intended only to define the "preset threshold value".

Further, the conductive substrate layer 1122b is also configured to: the roughness of the side of conductive substrate layer 1122b facing away from foil layer 111b is greater than the roughness of foil layer major surface 101 b. Since the main surface 101 of the foil layer 111b is generally smooth, if the conductive layer 1121b is directly coated on the main surface 101 by a coating process, a slipping phenomenon may occur, so that the thickness of the conductive layer 1121b is uneven, and a partial area of the foil layer 111b may be exposed; and partial exposure of the foil layer 111b may still cause precipitation of elemental elements of the foil layer 111b on the surface of the pole piece. The above arrangement of the conductive substrate layer 1122b is beneficial to increasing the friction force when the conductive layer 1121b is coated, so as to reduce the probability of the occurrence of the slipping phenomenon, further ensure that the thickness of the conductive layer 1121b is relatively uniform, and reduce the hidden trouble of separating out the metal simple substance of the foil on the surface of the pole piece 100 to a certain extent. More preferably, the roughness of the side of the conductive base material layer 1122b in contact with the foil layer 111 is greater than the roughness of the side of the conductive layer 1121b facing the foil layer 111 b; this is advantageous in increasing the friction force when the conductive base material layer 1122b is applied to the foil layer 111 b. In this embodiment, the conductive substrate layer 1122b is a nano-carbon layer with a better roughness. Of course, in other embodiments of the present application, the conductive substrate layer 1122b may be attached to the main surface 101 by other methods than coating, such as spraying. Alternatively, the thickness of the conductive substrate layer 1122b is between 0.2 μm and 2 μm.

For the active material layer 120, please further combine fig. 1 and 2, the active material layer 120 is a core material layer of the pole piece 100, and is disposed on a side of the conductive layer 1121 facing away from the foil layer 111. The active material layer 120 includes graphite, a conductive agent, an adhesive, and deionized water, and the materials are uniformly mixed and coated on the conductive material layer 112, thereby obtaining the active material layer 120. It will be appreciated that the specific composition of the active material layer 120 is in fact varied and is not limited in this application; for example, in other embodiments, the active material layer 120 may also include carbon-containing compounds.

It should be noted that, when the active material layer 120 is coated on the conductive material layer 112, the active material layer 120 generally falls within the edge of the conductive material layer 112 due to limitations in the accuracy of the coating process. Specifically, along the extending direction of the long side, the active material layer 120 is entirely located between the two ends of the conductive layer 1121, that is, the two ends of the conductive layer 1121 respectively exceed the two ends of the active material layer 120. Alternatively, the conductive layer 1121 is provided to exceed the dimension Δl of the active material layer 120 by more than 0.5mm on each side in the above-described long-side direction, the dimension range being set so as to avoid too small a difficulty in completion at the time of coating; further alternatively, the dimension Δl is between 0.5mm and 2mm, and the dimension range is set to avoid excessively large resulting in low energy density of the battery cell using the pole piece 100. Similarly, along the extending direction of the wide edge, the active material layer 120 is entirely located between two ends of the conductive layer 1121, that is, two ends of the conductive layer 1121 respectively exceed two ends of the active material layer 120. Alternatively, the conductive layer 1121 is provided to have a dimension Δw exceeding the active material layer 120 by more than 0.5mm on one side in the above-described broadside direction, the dimension being set so as to avoid too small a dimension that would cause an excessive difficulty in coating; further alternatively, the dimension Δw is between 0.5mm and 2mm, and the dimension range is set to avoid excessively large resulting in low energy density of the battery cell using the pole piece 100. Of course, the portion of the conductive layer 1121 beyond the active material layer 120 may be removed by cutting, thereby improving the energy density of the entire pole piece 100.

The current collector 110 of the pole piece 100 provided in the embodiment of the present application includes, in addition to the foil layer 111, a conductive material layer 112 provided on the main surface 101 of the foil layer 111. Wherein the conductive material layer 112 comprises a conductive layer 1121, the standard electrode potential of at least one conductive material in the conductive layer 1121 is higher than the standard electrode potential of the foil layer 111. In the area where the foil layer 111 is directly or indirectly covered by the conductive material above the standard electrode potential, the conductive layer 1121 can prevent the metal element from being deposited on the outer surface of the conductive layer 1121, that is, the outer surface of the current collector 110, by means of physical isolation, even if the foil layer 111 has a tendency of depositing the metal element, so as to avoid depositing the metal element of the foil on the surface of the electrode plate in the battery cell. Further, since the standard electrode potential of at least one conductive material in the conductive layer 1121 is greater than the standard electrode potential of the foil layer 111; therefore, the conductive material above the standard electrode potential of the foil layer is not easily oxidized before the potential is increased to the point that the foil layer is completely oxidized and dissolved; therefore, the conductive layer 1121 is not easily oxidized, and simple substances are prevented from being separated out on the surface of the pole piece in the charge and discharge process. In conclusion, the surface of the pole piece 100 is not easy to separate out metal simple substance; therefore, the pole piece 100 provided in the embodiment of the present application can improve the current situation that the metal element may be separated out from the surface of the pole piece in the charging and discharging process of the current battery cell.

Based on the same inventive concept, another embodiment of the present application further provides a current collector, which has the same structure as the current collector in the pole piece 100 in any of the above embodiments, so that a detailed structure of the current collector is not described herein. Similarly, when the current collector is applied to the battery cell, the current situation that the surface of the pole piece of the battery cell is likely to separate out metal simple substances in the charging and discharging process can be improved.

Based on the same inventive concept, another embodiment of the present application further provides a battery cell, specifically, please refer to fig. 5, which shows a schematic diagram of the battery cell 1, and in combination with fig. 1 to 4, the battery cell 1 includes a housing, an electrode assembly, and a tab. The electrode assembly includes two electrode sheets of opposite polarity, at least one of which is electrode sheet 100 in any of the embodiments described above. In this embodiment, the anode sheet of the battery core 1 is the above-mentioned pole piece 100, and the cathode sheet is a pole piece with a conventional structure. It will be appreciated that in other embodiments of the present application, both pole pieces may be the pole piece 100 described above; of course, at this time, the materials of the two electrode sheet foil layers are different materials, for example, the foil layer of the anode sheet comprises copper foil, and the foil layer of the cathode sheet comprises aluminum foil; similarly, the active material layers of the two pole pieces are also made of different material compositions. The battery cell can improve the current situation that the surface of the electrode plate is likely to separate out metal simple substances in the charging and discharging process of the battery cell.

Based on the same inventive concept, another embodiment of the present application further provides an electrical device 2, referring specifically to fig. 6, and referring to fig. 1 to 5, the electrical device 2 includes the electrical core in the foregoing embodiment. In this embodiment, the power consumption device 2 is a mobile phone; it will be appreciated that in other embodiments of the present application, the power consumption device 2 may be a tablet computer, a computer, an unmanned aerial vehicle, or other power consumption devices that need to be driven by electricity.

The battery cell 1 in the embodiment is included, so that the current situation that the surface of the pole piece of the battery cell in the current power utilization device possibly precipitates a metal simple substance in the charging and discharging process can be improved by the power utilization device 2.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; the technical features of the above embodiments or in the different embodiments may also be combined under the idea of the present application, the steps may be implemented in any order, and there are many other variations of the different aspects of the present application as described above, which are not provided in details for the sake of brevity; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A current collector comprising a foil layer having a major surface defined by a length and a width of the foil layer, characterized by further comprising a layer of conductive material;

the conductive material layer is arranged on the main surface, the conductive material layer comprises a conductive substrate layer and a conductive layer, the conductive substrate layer is arranged on the main surface, and the roughness of one side of the conductive substrate layer, which is away from the foil layer, is larger than that of the main surface; the conductive layer comprises more than one conductive material, the conductive layer is arranged on one side, away from the foil layer, of the conductive substrate layer so as to cover at least part of the main surface, the standard electrode potential of at least one conductive material in the conductive layer is greater than that of the foil layer, and the conductive layer can prevent metal simple substances of the foil layer from precipitating to the outer surface of the conductive layer in a physical isolation mode.

2. The current collector of claim 1, wherein the at least one conductive material comprises at least one of silver, platinum, and gold.

3. The current collector of claim 1, wherein an adhesion force between the conductive substrate layer and the conductive layer is greater than a preset threshold, the adhesion force between the conductive substrate layer and the foil layer is greater than the preset threshold, and the preset threshold is an adhesion force value of the conductive layer and the foil layer when directly adhered.

4. A current collector as in claim 3, wherein the material of the conductive substrate layer comprises at least one of a carbon nanocarbon layer, carbon nanotubes, and conductive carbon black.

5. A current collector according to claim 3, wherein the foil layer has a thickness of 3 μm to 20 μm, the conductive layer has a thickness of 0.2 μm to 20 μm, and the conductive base layer has a thickness of 0.2 μm to 2 μm.

6. A current collector according to any one of claims 1 to 5 wherein the foil layer has two opposed major surfaces, both of which are provided with the layer of electrically conductive material.

7. A cell comprising a pole piece, characterized in that the pole piece comprises an active material layer and a current collector according to any one of claims 1 to 6, the active material layer being provided on a side of the conductive layer facing away from the foil layer.

8. The cell of claim 7, wherein the conductive layer has ends that extend beyond the corresponding ends of the active material layer by a distance greater than 0.5mm in the direction of extension of the broad sides of the current collector.

9. The cell defined in claim 7, wherein the conductive layer has ends that extend beyond the corresponding ends of the active material layer in the direction of extension of the long sides of the current collector.

10. An electrical device comprising a cell as claimed in any one of claims 7 to 9.