CN216648361U

CN216648361U - Negative plate, preparation device of negative plate and battery cell

Info

Publication number: CN216648361U
Application number: CN202122764635.7U
Authority: CN
Inventors: 卢军太; 魏建良; 高书尧; 丁阳; 张传键; 朱金保
Original assignee: Jiangsu Zenio New Energy Battery Technologies Co Ltd
Current assignee: Jiangsu Zenio New Energy Battery Technologies Co Ltd
Priority date: 2021-11-12
Filing date: 2021-11-12
Publication date: 2022-05-31
Anticipated expiration: 2031-11-12

Abstract

The utility model discloses a negative plate, a preparation device of the negative plate and a battery cell, and relates to the technical field of batteries; the negative plate comprises a base film, a first copper layer, a second copper layer, a first lithium layer, a second lithium layer, a first negative electrode active material layer and a second negative electrode active material layer, wherein the first copper layer, the first lithium layer and the first negative electrode active material layer are sequentially arranged on the first side of the base film, and the second copper layer, the second lithium layer and the second negative electrode active material layer are sequentially arranged on the second side of the base film. On the one hand, this negative pole piece sets up copper layer and lithium layer through adopting the base member film and uses as the mass flow body after with the top layer of base member film, can avoid using whole copper foil as the mass flow body, can reduce cost, and because weight is also lower relatively to can improve energy density, on the other hand, the lithium ion that electric core charge-discharge in-process consumed can be replenished in the joining of lithium layer again, guarantees electric core capacity.

Description

Negative plate, preparation device of negative plate and battery cell

Technical Field

The utility model relates to the technical field of batteries, in particular to a negative plate, a negative plate preparation device and a battery cell.

Background

At present, a copper foil is generally adopted as a negative electrode current collector of a negative electrode piece of a lithium ion power battery, and the negative electrode piece is high in cost, heavy in weight and relatively low in energy density.

SUMMERY OF THE UTILITY MODEL

One of the purposes of the utility model is to provide a negative plate, on one hand, the surface layer of the matrix film is provided with a copper layer and a lithium layer and then is used as a current collector, so that the use of the whole copper foil as the current collector can be avoided, the cost can be reduced, and the energy density can be improved because the weight is relatively lower, and on the other hand, the addition of the lithium layer can supplement lithium ions consumed in the charge and discharge process of a battery cell, so as to ensure the capacity of the battery cell; meanwhile, the arrangement of the matrix film can also prevent or delay thermal runaway diffusion, so that the safety performance of the battery cell can be effectively improved.

The second objective of the present invention is to provide an apparatus for preparing the negative electrode sheet, which can rapidly and effectively prepare the negative electrode sheet and ensure the quality of the negative electrode sheet.

The utility model also provides a battery cell, which comprises the negative plate. Therefore, it also has advantages of low cost, high energy density, high capacity and high safety.

The embodiment of the utility model is realized by the following steps:

in a first aspect, the present invention provides a negative electrode sheet, comprising:

the lithium battery comprises a base film, a first copper layer, a second copper layer, a first lithium layer, a second lithium layer, a first negative electrode active material layer and a second negative electrode active material layer, wherein the first copper layer, the first lithium layer and the first negative electrode active material layer are sequentially arranged on the first side of the base film, and the second copper layer, the second lithium layer and the second negative electrode active material layer are sequentially arranged on the second side of the base film.

In an alternative embodiment, the first copper layer has a thickness of 3 to 10 μm; and/or the thickness of the second copper layer is 3-10 μm.

In an alternative embodiment, the first lithium layer has a thickness of 2 to 20 μm; and/or the thickness of the second lithium layer is 2-20 mu m.

In an alternative embodiment, the base film is a polymer insulating film.

In an alternative embodiment, the thickness of the base film is 3 to 20 μm.

In a second aspect, the present invention provides an apparatus for manufacturing a negative electrode sheet according to any one of the preceding embodiments, comprising:

the unreeling component, the copper plating component, the lithium plating component, the coating component and the reeling component are sequentially arranged in the vacuum chamber; the unwinding assembly is used for unwinding the matrix film, a plurality of conveying rollers for conveying the matrix film are arranged between the unwinding assembly and the winding assembly, and the winding assembly is used for winding the matrix film; the copper-plated assembly is used for plating a first copper layer and a second copper layer on the first side and the second side of the base film respectively, the lithium-plated assembly is used for plating a first lithium layer and a second lithium layer on the first copper layer and the second copper layer respectively, and the coating assembly is used for coating a first negative electrode active material layer and a second negative electrode active material layer on the first lithium layer and the second lithium layer respectively.

In an alternative embodiment, the copper plating assembly comprises a first copper plating member disposed on a first side of the base film for plating a first copper layer on the first side of the base film, and a second copper plating member disposed on a second side of the base film for plating a second copper layer on the second side of the base film;

and/or the presence of a gas in the gas,

the lithium plating assembly comprises a first lithium plating piece and a second lithium plating piece, the first lithium plating piece is arranged on the first side of the base film and used for plating a first lithium layer on the first copper layer, and the second copper plating piece is arranged on the second side of the base film and used for plating a second lithium layer on the second copper layer.

In an optional embodiment, the vacuum chamber comprises a first chamber and a second chamber which are independently arranged, the unreeling assembly and the copper plating assembly are arranged in the first chamber, and the lithium plating assembly, the coating assembly and the reeling assembly are arranged in the second chamber.

In an optional embodiment, a first cooling assembly is further arranged in the first chamber, and the first cooling assembly is used for cooling a first copper layer and a second copper layer formed by copper plating of the copper plating assembly;

and/or the presence of a gas in the gas,

and a second cooling assembly is further arranged in the second cavity and used for cooling the first lithium layer and the second lithium layer formed by lithium plating of the lithium plating assembly.

In a third aspect, the present invention provides a battery cell, including the negative electrode tab of any one of the foregoing embodiments.

The embodiment of the utility model has at least the following advantages or beneficial effects:

the embodiment of the utility model provides a negative plate which comprises a base film, a first copper layer, a second copper layer, a first lithium layer, a second lithium layer, a first negative electrode active material layer and a second negative electrode active material layer, wherein the first copper layer, the first lithium layer and the first negative electrode active material layer are sequentially arranged on a first side of the base film, and the second copper layer, the second lithium layer and the second negative electrode active material layer are sequentially arranged on a second side of the base film. On the one hand, this negative pole piece sets up the copper layer and uses as the mass flow body after the lithium layer through adopting the base member film with the top layer of base member film, can avoid using whole copper foil as the mass flow body, can reduce cost, and because weight is also lower relatively to can improve energy density, on the other hand, the lithium ion that electric core charge-discharge in-process consumed can be replenished in the addition on lithium layer again, guarantees electric core capacity.

The embodiment of the utility model also provides a preparation device of the negative plate, which can be used for quickly and effectively preparing the negative plate and ensuring the quality of the negative plate.

The embodiment of the utility model also provides a battery cell, which comprises the negative plate. Therefore, it also has the advantages of low cost, high energy density, and high capacity.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a negative electrode sheet provided in an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a negative electrode sheet preparation apparatus according to an embodiment of the present invention.

The icon is 100-negative plate; 101-a base film; 103-a first copper layer; 105-a second copper layer; 107-first lithium layer; 109-a second lithium layer; 111 — a first anode active material layer; 113 — a second anode active material layer; 200-a preparation device of the negative plate; 201-an unwinding assembly; 202-a copper plated component; 203-a first copper plated part; 205-a second copper plated part; 206-a lithium plated component; 207-first lithium plated item; 209-a second lithium plated part; 211-a coating assembly; 213-a winding component; 215-a first cooling element; 217-a second cooling element; 219 — third cooling element; 221-a fourth cooling member; 223-conveying rollers; 225-vacuum pumping mechanism; 227-a deviation correcting mechanism; 231-a first chamber; 233-second chamber.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element to which the description refers must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are required to be absolutely horizontal or pendant, but rather may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

At present, a copper foil is generally adopted as a negative electrode current collector of a lithium ion power battery, and the negative electrode current collector has the advantages of high cost, high density, heavy weight and relatively low energy density. In view of this, the present embodiment provides a negative electrode plate, which uses a composite structure formed by disposing a copper layer and a lithium layer on a surface layer of a matrix film as a current collector, and can avoid using the entire copper foil as the current collector, thereby reducing the cost, and since the weight is relatively lower, the energy density can be improved, and the safety performance can be effectively improved through the matrix film. The negative electrode sheet, the apparatus for preparing the negative electrode sheet, and the cell structure comprising the negative electrode sheet will be described in detail below.

Fig. 1 is a schematic structural diagram of a negative electrode sheet 100 provided in this embodiment. Referring to fig. 1, the present embodiment provides a negative electrode sheet 100, which includes a base film 101, a first copper layer 103, a second copper layer 105, a first lithium layer 107, a second lithium layer 109, a first negative electrode active material layer 111, and a second negative electrode active material layer 113. Further, the base film 101 is positioned in the middle, the first copper layer 103, the first lithium layer 107, and the first negative electrode active material layer 111 are sequentially provided on the first side of the base film 101, and the second copper layer 105, the second lithium layer 109, and the second negative electrode active material layer 113 are sequentially provided on the second side of the base film 101.

On the one hand, because the mass flow body of prior art adopts the copper foil preparation, its is with high costs, weight is big, and energy density is also relatively lower, therefore this embodiment sets up the surface layer of base film 101 and uses as the mass flow body after copper layer and lithium layer, can avoid using whole copper foil as the mass flow body, can reduce cost, and because weight is also lower relatively to can improve energy density. On the other hand, because among the prior art electric core when charging for the first time, because the formation of SEI membrane, can consume some lithium ion for this part lithium ion can't become the active lithium that can provide effective capacity for electric core, causes the loss of battery capacity, therefore the mass flow body that this embodiment provided includes the lithium layer, can also mend the lithium ion that electric core charge-discharge in-process consumed, guarantees electric core capacity, thereby guarantees electric core charge-discharge safety and the reliability of process. Meanwhile, the number of the copper layers and the number of the lithium layers in the embodiment are two, so that the energy density and the cycle life of the battery cell can be better ensured compared with the case that one layer is independently arranged.

Alternatively, in the present embodiment, the base film 101 is specifically selected to be a polyethylene terephthalate film, that is, a PET film. The PET film is selected as the base film 101, so that the safety of the battery can be effectively improved by utilizing the insulating property of the material, the current can be cut off in time when the short circuit occurs in the battery core, the occurrence probability of thermal runaway is reduced, and the safety and the stability of the battery core are ensured. Of course, in other embodiments, the substrate film 101 may also be selected as other polymer insulating films, such as a PP film, and the like, which is not described in detail in this embodiment.

In the present embodiment, the thickness of the base thin film 101 is 3 to 20 μm. The thickness of the matrix film 101 is controlled within the range, so that the overall weight of the current collector can be reduced, and the safety can be improved, so that the safety and the reliability of the charge and discharge operation of the battery cell can be fully ensured.

Further optionally, in this embodiment, the first copper layer 103 and the second copper layer 105 are disposed on both sides of the base film 101 by copper plating, and both thicknesses thereof are set to be 3 to 10 μm. Controlling the thickness of the copper layer within this range not only saves cost, but also ensures energy density. Meanwhile, the first lithium layer 107 and the second lithium layer 109 are also disposed above the copper layer by lithium plating, and the thickness of the lithium plating is 2-20 μm. The thickness of the lithium layer is controlled within the range, so that the weight of the whole current collector can be reduced, lithium can be fully supplemented, and the capacity of the battery cell is ensured, so that the safety, reliability and stability of the battery cell in the charging and discharging process can be further ensured, and the operating efficiency and quality are ensured.

The embodiment of the utility model also provides a battery cell, which comprises the negative plate 100, a positive plate and an isolating membrane, wherein the negative plate 100 and the positive plate are respectively arranged on two sides of the isolating membrane and then wound to form a flat structure. The battery cell has the advantages of low cost, high energy density and high capacity due to the inclusion of the negative plate 100. Meanwhile, the PET film in the negative plate 100 can also effectively prevent thermal runaway, so that the safety of the battery cell is fully improved, and the efficiency and quality of the battery cell charge-discharge operation can be further ensured.

Fig. 2 is a schematic structural diagram of a negative electrode sheet preparation apparatus 200 according to this embodiment. Referring to fig. 2, the present embodiment further provides a negative electrode sheet manufacturing apparatus 200, and the negative electrode sheet manufacturing apparatus 200 can manufacture the negative electrode sheet 100.

In detail, referring to fig. 2 again, in the present embodiment, the apparatus 200 for preparing a negative electrode sheet specifically includes an unwinding assembly 201, a copper plating assembly 202, a lithium plating assembly 206, a coating assembly 211, and a winding assembly 213 sequentially disposed in a vacuum chamber, wherein the vacuum chamber is vacuum-pressed at 100 Pa.

Unreel subassembly 201 including unreeling the roller and drive unreel the roller pivoted drive piece that unreels, base member film 101 can be convoluteed on unreeling the roller, when unreeling the drive of drive piece and unreeling the roller and rotate, unreel the roller and can unreel the operation. The winding assembly 213 is similar to the unwinding assembly 201 in structure, and includes a winding roller and a winding driving member for driving the winding roller to rotate, the substrate film 101 can be wound on the winding roller, and when the winding driving member drives the winding roller to rotate, the winding roller can perform winding operation. Meanwhile, in order to ensure that the substrate film 101 can move from the position of the unwinding assembly 201 to the position of the winding assembly 213, a plurality of conveying rollers 223 arranged at intervals are arranged between the unwinding assembly 201 and the winding assembly 213, and the conveying rollers 223 can support the substrate film 101 and rotate under the driving of the driving member to convey the substrate film 101, so that the substrate film 101 after the unwinding of the unwinding roller can be smoothly wound on the winding roller.

The copper plating assembly 202 and the lithium plating assembly 206 are disposed between the unwinding assembly 201 and the winding assembly 213, the copper plating assembly 202 is used for plating the first copper layer 103 and the second copper layer 105 on the first side and the second side of the base film 101, respectively, and the lithium plating assembly 206 is used for plating the first lithium layer 107 and the second lithium layer 109 on the first copper layer 103 and the second copper layer 105, respectively, to obtain a current collector structure.

The coating assembly 211 is disposed at a position close to the wind-up roll, and may be selected to have two coating heads located at two sides of the substrate film 101, or may be selected to be a coater capable of performing double-sided coating simultaneously, the coating assembly 211 may be configured to coat the first negative electrode active material layer 111 and the second negative electrode active material layer 113 on the first lithium layer 107 and the second lithium layer 109, respectively, the humidity of the coating environment may be controlled to be less than 1%, and the negative electrode sheet 100 may be obtained by drying after coating.

This negative pole piece's preparation facilities 200 is through setting up unreeling subassembly 201, copper facing subassembly 202, lithium plating subassembly 206, coating subassembly 211 and rolling subassembly 213 in the vacuum chamber, can guarantee preparation efficiency and quality, so that can set gradually first copper layer 103, first lithium layer 107 and first negative pole active material layer 111 under the cooperation of several above-mentioned subassemblies fast and reliably at the first side of matrix film 101, set gradually second copper layer 105 at the second side of matrix film 101, second lithium layer 109 and second negative pole active material layer 113, thereby can fully and effectively guarantee the security and the energy density of electric core.

In the copper plating or lithium plating process, the thickness is 3-10 μm for the copper layer and 2-20 μm for the lithium layer. In other embodiments, the thicknesses of the copper layer and the lithium layer may also be adjusted according to the cost, which is not described in detail in this embodiment.

Alternatively, in the present embodiment, the vacuum chamber includes the first chamber 231 and the second chamber 233 which are independently arranged, and the base film 101 can move to the second chamber 233 through the first chamber 231 and also move to the first chamber 231 through the second chamber 233. Meanwhile, the unwinding assembly 201 and the copper plating assembly 202 are disposed in the first chamber 231, and the lithium plating assembly 206, the coating assembly 211 and the winding assembly 213 are disposed in the second chamber 233. The chambers for copper plating and lithium plating are separately and independently arranged, so that mutual interference and pollution can be avoided, and the environment in the first chamber 231 and the environment in the second chamber 233 can be conveniently set to meet the requirements of copper plating and lithium plating, so that the efficiency and quality of lithium plating and copper plating can be fully ensured.

In this embodiment, the vacuum environments of the first chamber 231 and the second chamber 233 are obtained by performing the vacuum process by using the vacuum mechanism 225. The number of the vacuum pumping mechanisms 225 may be one, so as to sequentially perform vacuum pumping on the first chamber 231 and the second chamber 233, or may be two, so that the first chamber 231 and the second chamber 233 are respectively provided with one, so as to perform vacuum pumping, which is not limited in this embodiment.

Referring to fig. 2 again, in the present embodiment, the copper plating assembly 202 located in the first chamber 231 specifically includes a first copper plating member 203 and a second copper plating member 205. The first copper-plated part 203 and the second copper-plated part 205 can be both configured as a laser copper-plated structure, and the first copper-plated part 203 is disposed on the first side of the base film 101 for plating the first copper layer 103 on the first side of the base film 101, and the second copper-plated part 205 is disposed on the second side of the base film 101 for plating the second copper layer 105 on the second side of the base film 101. Similarly, the lithium plating assembly 206 located in the second chamber 233 specifically includes a first lithium plating member 207 and a second lithium plating member 209. The first lithium plating part 207 and the second lithium plating part 209 are both also in a laser lithium plating structure, and the first lithium plating part 207 is disposed on the first side of the base film 101 for plating the first lithium layer 107 on the first copper layer 103, and the second lithium plating part 209 is disposed on the second side of the base film 101 for plating the second lithium layer 109 on the second copper layer 105. The efficiency and quality of copper plating and lithium plating can be ensured through the first copper plating piece 203, the second copper plating piece 205, the first lithium plating piece 207 and the second lithium plating piece 209, so that the quality of the negative plate 100 can be ensured, and further the quality of the battery cell can be ensured.

Optionally, in this embodiment, a first cooling assembly is further disposed in the first chamber 231, and the first cooling assembly is configured to cool the first copper layer 103 and the second copper layer 105 formed by copper plating by the copper plating assembly 202 to a temperature below 45 ℃. The second chamber 233 is further provided with a second cooling assembly, and the second cooling assembly is used for cooling the first lithium layer 107 and the second lithium layer 109 formed by lithium plating of the lithium plating assembly 206, and is also cooled to below 45 ℃. The first cooling assembly and the second cooling assembly are arranged, so that the quality of copper plating and lithium plating can be further improved, the yield is improved, the waste is reduced, and the cost is further reduced.

The first cooling assembly specifically comprises a first cooling piece 215 and a second cooling piece 217, wherein the first cooling piece 215 and the second cooling piece 217 are respectively located on two sides of the base material film and are respectively used for cooling the surface plated with the first copper layer 103 and the surface plated with the second copper layer 105 so as to ensure the efficiency and quality of copper plating. Similarly, the second cooling assembly specifically comprises a third cooling member 219 and a fourth cooling member 221, and the third cooling member 219 and the fourth cooling member 221 are also respectively located on two sides of the substrate film and are respectively used for cooling the surface after the first lithium layer 107 is plated and the surface after the second lithium layer 109 is plated, so as to ensure the efficiency and quality of lithium plating. Of course, in other embodiments, a cooling element may be disposed in each of the first chamber 231 and the second chamber 233, so that one cooling element in the first chamber 231 can simultaneously cool the first copper layer 103 and the second copper layer 105 after copper plating, and one cooling element in the second chamber 233 can simultaneously cool the first lithium layer 107 and the second lithium layer 109 after lithium plating, which is not limited in this embodiment.

It should be noted that, in this embodiment, the cooling mode may be selected as cooling with cool air introduced into vacuum, or closed water cooling may also be adopted, so as to ensure the cooling effect, and this embodiment is not described again.

Further optionally, referring to fig. 2 again, in this embodiment, the negative plate manufacturing apparatus 200 further includes two deviation rectification mechanisms 227, one deviation rectification mechanism 227 is disposed adjacent to the unwinding assembly 201, and the other deviation rectification mechanism 227 is disposed adjacent to the winding assembly 213, so as to ensure stability of the winding and unwinding processes and ensure accuracy and reliability of the negative plate 100 manufacturing process.

The operation principle and advantageous effects of the apparatus 200 for manufacturing a negative electrode sheet according to an embodiment of the present invention will be described in detail as follows:

when the negative electrode sheet 100 is manufactured by using the negative electrode sheet manufacturing apparatus 200, the first chamber 231 and the second chamber 233 may be first vacuumized to below 100Pa by using the vacuuming mechanism 225, and then the unwinding assembly 201, the winding assembly 213, the copper plating assembly 202, the lithium plating assembly 206, and the coating assembly 211 are started, so that the first copper layer 103 is first plated on the first side of the base film 101, the second copper layer 105 is conveyed downstream after cooling, the second copper layer is conveyed into the second chamber 233 and is plated with the first lithium layer 107, the second lithium layer 109 is conveyed downstream after cooling, the first negative electrode active material layer 111 and the second negative electrode active material layer 113 are sequentially coated, and then the manufacturing operation is completed after drying.

In the negative electrode sheet 100 prepared by the above process, the first copper layer 103, the first lithium layer 107 and the first negative electrode active material layer 111 can be rapidly disposed on the first side of the base film 101 in sequence, and the second copper layer 105, the second lithium layer 109 and the second negative electrode active material layer 113 can be rapidly disposed on the second side of the base film 101 in sequence, so that the preparation efficiency and the quality are high. And on the one hand, compared with the method that the whole copper foil is adopted as a current collector, the cost can be reduced, and the weight is relatively lower, so that the energy density can be improved, and on the other hand, the lithium layer can supplement lithium ions consumed in the charge and discharge process of the battery cell, so that the capacity of the battery cell is ensured.

In summary, the embodiments of the present invention provide a negative electrode sheet 100 and a battery cell with low cost, high energy density and high capacity, and provide a manufacturing apparatus 200 for manufacturing a negative electrode sheet with high efficiency and quality.

The present invention has been described in terms of the preferred embodiment, and it is not intended to be limited to the embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A negative electrode sheet, comprising:

the lithium battery comprises a base film, a first copper layer, a second copper layer, a first lithium layer, a second lithium layer, a first negative electrode active material layer and a second negative electrode active material layer, wherein the first copper layer is sequentially arranged on the first side of the base film, and the second copper layer is sequentially arranged on the second lithium layer and the second negative electrode active material layer.

2. A negative electrode sheet according to claim 1, characterized in that:

the thickness of the first copper layer is 3-10 mu m; and/or the thickness of the second copper layer is 3-10 mu m.

3. A negative electrode sheet according to claim 1, characterized in that:

the thickness of the first lithium layer is 2-20 mu m; and/or the thickness of the second lithium layer is 2-20 mu m.

4. A negative electrode sheet according to claim 1, characterized in that:

the substrate film is a polymer insulating film.

5. The negative electrode sheet according to claim 1, wherein:

the thickness of the substrate film is 3-20 μm.

6. A negative-electrode-sheet production apparatus according to any one of claims 1 to 5, comprising:

the unreeling component, the copper plating component, the lithium plating component, the coating component and the reeling component are sequentially arranged in the vacuum chamber; the unwinding assembly is used for unwinding the base film, a plurality of conveying rollers for conveying the base film are arranged between the unwinding assembly and the winding assembly, and the winding assembly is used for winding the base film; the copper plating assembly is used for plating the first copper layer and the second copper layer on the first side and the second side of the base film respectively, the lithium plating assembly is used for plating the first lithium layer and the second lithium layer on the first copper layer and the second copper layer respectively, and the coating assembly is used for coating the first negative electrode active material layer and the second negative electrode active material layer on the first lithium layer and the second lithium layer respectively.

7. The negative-electrode-sheet manufacturing apparatus according to claim 6, characterized in that:

the copper plating assembly comprises a first copper plating piece and a second copper plating piece, the first copper plating piece is arranged on the first side of the base film and used for plating the first copper layer on the first side surface of the base film, and the second copper plating piece is arranged on the second side of the base film and used for plating the second copper layer on the second side surface of the base film;

and/or the presence of a gas in the gas,

the lithium plating assembly comprises a first lithium plating piece and a second lithium plating piece, the first lithium plating piece is arranged on the first side of the base film and used for plating the first lithium layer on the first copper layer, and the second copper plating piece is arranged on the second side of the base film and used for plating the second lithium layer on the second copper layer.

8. The negative-electrode-sheet manufacturing apparatus according to claim 6, characterized in that:

the vacuum chamber comprises a first chamber and a second chamber which are independently arranged, the unreeling assembly and the copper-plated assembly are arranged in the first chamber, and the lithium-plated assembly, the coating assembly and the rolling assembly are arranged in the second chamber.

9. The negative-electrode-sheet manufacturing apparatus according to claim 8, characterized in that:

the first cooling assembly is arranged in the first cavity and used for cooling the first copper layer and the second copper layer formed by copper plating of the copper plating assembly;

and/or the presence of a gas in the gas,

10. A battery cell, comprising the negative electrode sheet of any one of claims 1 to 5.