CN116169303A - Composite copper foil, manufacturing method thereof and battery - Google Patents

Abstract

The application provides a composite copper foil, a manufacturing method thereof and a battery. Wherein, the compound copper foil includes: the conductive part comprises a substrate, a conductive part and a copper layer, wherein a groove is formed in the surface of the substrate; the conductive part is arranged in the groove; the copper layer is arranged on the surface of the base material and covers the conductive part. According to the technical scheme, heat generation in the composite copper foil can be reduced, and the internal overheating condition of the battery is reduced.

Description

Composite copper foil, manufacturing method thereof and battery

Technical Field

The application relates to the technical field of copper foil production, in particular to a composite copper foil, a manufacturing method thereof and a battery.

Background

The current copper foil material is mainly copper, and is generally processed by an electrolytic mode, and is also called electrolytic copper foil. The composite copper foil is formed by using a polymer material instead of a part of copper. The composite copper foil has the advantages of high energy density and lower cost.

However, the reduction in the thickness of the copper layer in the composite copper foil compared with the conventional electrolytic copper foil leads to an increase in the resistance value of the composite copper foil, resulting in a large amount of heat generated during use of the battery of the composite copper foil. And the polymer substrate is used as an insulator, so that heat generated in the running process of the battery is difficult to transfer and release to the outside, the decomposition of various active substances in the battery is accelerated, the service life of the battery is reduced, and potential safety hazards caused by overheat in the battery are also brought.

Disclosure of Invention

An object of the present application is to provide a composite copper foil, a method for manufacturing the same, and a battery, which can reduce heat generation in the composite copper foil and reduce overheating of the inside of the battery.

According to one aspect of the present application, there is provided a composite copper foil comprising:

a substrate, the surface of which is provided with a groove;

the conductive part is arranged in the groove;

and the copper layer is arranged on the surface of the base material and covers the conductive part.

In one aspect, the grooves are arranged in a plurality, and the grooves are distributed on the surface of the base material at equal intervals.

In one aspect, the conductive portion includes at least one of inorganic non-metallic conductive particles or metallic conductive particles.

In one aspect, the inorganic nonmetallic conductive particles comprise at least one of graphene or carbon nanotubes;

the metal conductive particles include at least one of gold, silver, copper, iron, nickel, tin, or aluminum.

In one aspect, the composite copper foil further comprises a conductive seed layer, wherein the conductive seed layer is arranged between the conductive part and the copper layer, and the conductive seed layer and the copper layer are the same in material.

In one aspect, the conductive portion has a thickness D, which satisfies: d is more than or equal to 0.1um and less than or equal to 0.5um.

In one aspect, the substrate has a first surface and a second surface disposed opposite to each other, the first surface is provided with grooves which are first grooves, the second surface is provided with grooves which are second grooves, and the first grooves and the second grooves are staggered with each other.

In addition, in order to solve the above problems, the present application also provides a method for manufacturing a composite copper foil, the method for manufacturing a composite copper foil comprising:

providing a substrate;

providing a groove on the surface of the base material;

covering the surface of the substrate and exposing the grooves, and depositing conductive particles in the grooves to form conductive parts;

and a copper layer is arranged on the surface of the base material provided with the conductive part.

In one aspect, the step of providing a copper layer on a surface of a substrate provided with the conductive portion includes:

depositing a conductive seed layer on the surface of the substrate;

and forming the copper layer according to the electroplating of the conductive seed layer.

In addition, in order to solve the above-described problems, the present application also provides a battery including a positive electrode terminal and a negative electrode terminal, the negative electrode terminal including the composite copper foil as described above.

In the technical scheme of this application, regard as the basis at the substrate, set up the recess at the surface of substrate, set up conductive part in the recess. The copper layer covers the surface of the substrate, and when the copper layer transmits current, the current can also pass through the conductive part. The sectional area of the current flowing through the conductor at the position of the groove is increased, and the resistance is reduced, so that the heat in the composite copper foil can be reduced, the internal overheat condition of the battery is reduced, and the use safety of the battery is ensured.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The above and other objects, features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

Fig. 1 is a schematic structural view of a composite copper foil according to a first embodiment of the present application.

Fig. 2 is a schematic structural view of the groove in the first embodiment of the present application.

Fig. 3 is a schematic view of the structure of the bottom surface of the groove with an arc shape in the present application.

Fig. 4 is a schematic structural view of the bottom surface of the groove with a triangular shape in the present application.

Fig. 5 is a schematic view of the structure of the groove extending along the length direction of the substrate.

Fig. 6 is a schematic view of the structure of the groove extending in the width direction of the substrate in the present application.

FIG. 7 is a schematic view of the structure of the grooves uniformly arranged on the surface of the substrate.

FIG. 8 is a schematic view of the arrangement of grooves in the middle and edges of the surface of a substrate in the present application.

Fig. 9 is a schematic structural view of the arrangement of grooves on both surfaces of a substrate in the present application.

Fig. 10 is a schematic step flow diagram of a method for manufacturing a composite copper foil according to a second embodiment of the present application.

Fig. 11 is a flowchart illustrating steps S410 and S420 of a method for manufacturing a composite copper foil according to a second embodiment of the present application.

The reference numerals are explained as follows:

110. a substrate; 120. a conductive portion; 130. a copper layer; 140. a conductive seed layer;

101. a first surface; 102. a second surface; 111. a groove; 111a, a first groove; 111b, a second groove; 112. a channel.

Detailed Description

While this application is susceptible of embodiment in different forms, there is shown in the drawings and will herein be described in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the application and is not intended to limit the application to that as illustrated herein.

Thus, reference to one feature indicated in this specification will be used to describe one of the features of an embodiment of the application, and not to imply that each embodiment of the application must have the described feature. Furthermore, it should be noted that the present specification describes a number of features. Although certain features may be combined together to illustrate a possible system design, such features may be used in other combinations not explicitly described. Thus, unless otherwise indicated, the illustrated combinations are not intended to be limiting.

In the embodiments shown in the drawings, indications of orientation (such as up, down, left, right, front and rear) are used to explain the structure and movement of the various elements of the present application are not absolute but relative. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the description of the position of these elements changes, the indication of these directions changes accordingly.

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The drawings are merely schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus a repetitive description thereof will be omitted.

Preferred embodiments of the present application are further elaborated below in conjunction with the drawings of the present specification.

Example 1

Referring to fig. 1, the composite copper foil in the technical scheme of the present application includes: a substrate 110, a conductive portion 120, and a copper layer 130. The material of the base material 110 is a polymer material, the base material 110 is used as a basic structure, the conductive portion 120 and the copper layer 130 are sequentially arranged on the surface of the base material 110, and the base material 110 is used as a basic structure to support the arrangement of the conductive portion 120 and the copper layer 130.

The surface of the substrate 110 is provided with a groove 111; the grooves 111 may be formed by laser etching or by simultaneous formation of the substrates 110. For example, when the substrate 110 is cured, the surface is embossed with the raised surface abrasive, and the grooves 111 are formed after curing. The laser etching method is mainly to apply a laser beam to the surface of the substrate 110, break chemical bonds of the substrate 110 under the action of photoelectricity or photo-thermal, and burn or evaporate before carbonization. The thickness of the substrate 110 is typically between 3um and 8um, such as 3um, 4um, 5um, 6um, 7um, or 8um.

The substrate 110 may be PET (polyethylene terephthalate), which is commonly referred to as polyethylene terephthalate, and is a milky white or pale yellow, highly crystalline polymer with a smooth and glossy surface. Creep resistance, fatigue resistance, abrasion resistance, good dimensional stability, small abrasion, high hardness and stable toughness; the influence of temperature is small. Has no toxicity, weather resistance, good chemical resistance stability, low water absorption, weak acid resistance and organic solvent resistance.

The base material 110 may also be PP (Polypropylene) material, namely polypropylene, which is a thermoplastic synthetic resin with excellent performance, is colorless semitransparent thermoplastic lightweight general-purpose plastic, and has chemical resistance, heat resistance, electrical insulation, high strength mechanical properties, good high wear resistance processing performance and the like.

The substrate 110 may also be PI (Polyimide) Polyimide, which is a highly reliable and flexible material with a low weight.

The conductive part 120 is arranged in the groove 111; the conductive portion 120 may be disposed in the recess 111 by vapor deposition or by filling. The conductive portion 120 is disposed within the recess 111 such that the surface of the conductive portion 120 is flush with the surface of the substrate 110. The copper layer 130 is facilitated to be able to contact the conductive portion 120, and the current is smoothly able to flow through the conductive portion 120. If the conductive portion 120 protrudes from the groove 111, the conductive portion 120 protruding from the surface of the substrate 110 may be removed by etching or polishing.

The copper layer 130 is disposed on the surface of the substrate 110 and covers the conductive portion 120. The copper layer 130 is used primarily to transmit current as the negative electrode of the cell. By using the base material 110 as a base structure, the copper layer 130 is disposed on the surface of the base material 110, and the copper layer 130 may directly contact the conductive portion 120 or may indirectly contact the conductive portion 120 through other components, so that when the copper layer 130 transmits a current, the current can flow through the conductive portion 120, which is equivalent to increasing the cross-sectional area of the copper layer 130 at the position of the groove 111.

In this regard, it can be explained by the formula that r=ρl/S, where L is the length of the copper layer 130 and ρ resistivity is constant, and the cross-sectional area S is inversely proportional to the resistance value R, which decreases with an increase in the cross-sectional area S. Q=i according to the formula joule law ² Rt shows that Q represents heat, I represents current, and t represents time. In the case of a constant time t and current I, the heat quantity Q is proportional to the resistance value R, and in the case of a decrease in the resistance value R, the heat quantity generated is reduced accordingly.

In the technical solution of the present embodiment, based on the substrate 110, a groove 111 is formed on the surface of the substrate 110, and a conductive portion 120 is disposed in the groove 111. The copper layer 130 covers the surface of the substrate 110, and when the copper layer 130 transmits a current, the current can also pass through the conductive portion 120. The cross-sectional area of the current flowing through the conductor at the position of the groove 111 is increased, and the resistance is reduced, so that the heat generation in the composite copper foil can be reduced, the internal overheat condition of the battery is reduced, and the use safety of the battery is ensured. At this time, the heat generated in the composite copper foil can be reduced, and the excessive metal copper dosage can be avoided.

Referring to fig. 2 to 4, the shape of the groove 111 is not limited to square, but may be arc-shaped or triangular, and the substrate 110 is required to be bent when the composite copper foil is wound, and the substrate 110 is easily tensioned. By providing the grooves 111, the tension can be released at the positions of the grooves 111, thereby avoiding the substrate 110 from being deformed too much to crack and even causing the substrate 110 and the copper layer 130 to separate.

Referring to fig. 5 and 6, the extending direction of the groove 111 may be along the length direction of the substrate 110 or may be along the width direction of the substrate 110. The X direction is the length direction, and the Y direction is the width direction. If the extending direction of the groove 111 is the X direction, the rolling direction of the substrate 110 is along the Y direction. When the extending direction of the groove 111 is the Y direction, the rolling direction of the substrate is along the X direction. Thus, the problem of disordered deformation in the rolling process of the base material 110 can be improved, and the rolling is easy. In addition, when the composite copper foil is wound, winding tension can be generated in the composite copper foil, and the tension can be released to a certain extent at the position of the groove 111 through the arrangement of the groove 111, so that the deformation problem is relieved.

Referring to fig. 7, in order to more effectively ensure the safety of the battery, a plurality of grooves 111 are provided, and the plurality of grooves 111 are arranged on the surface of the substrate 110 at equal intervals. And the grooves 111 are provided with the communicated channels 112, and conductive metal can be arranged at the positions of the channels 112, so that the conductive parts 120 can be communicated, and the conductivity is further improved.

In addition, as shown in fig. 8, in order to reduce the overheating condition of the middle area of the composite copper foil, the arrangement of the grooves 111 may be more dense in the middle position of the substrate 110, and less dense in the edge position of the substrate 110. The edge of the substrate 110 is close to the outside, so that heat dissipation is fast, and the arrangement of the conductive portion 120 can be reduced. In the middle area, the environment is relatively closed, and the heat dissipation is slow. At this time, by providing more conductive portions 120, the resistance of the intermediate region is reduced, and thus the heat generation in the middle is reduced.

In addition, by arranging more conductive parts 120 in the middle and arranging fewer conductive parts 120 at the edge positions, the heat dissipation effect of the middle heat and the edge heat of the composite copper foil can be balanced, the situation that the local position of the composite copper foil is larger in thermal deformation is reduced, and the extrusion deformation among the internal structures of the composite copper foil is reduced.

In order to ensure that the conductive portion 120 can exert a conductive effect, the conductive portion 120 includes at least one of inorganic non-metallic conductive particles or metallic conductive particles.

These include three cases, the first case being that the conductive portion 120 includes inorganic nonmetallic conductive particles; in the second case, the conductive part 120 includes metal conductive particles. In the third case, the conductive part 120 includes a mixture of inorganic nonmetallic conductive particles and metallic conductive particles. By disposing these conductive particles within the recess 111, the recess 111 can be filled as fully as possible.

A conductive paste may be further disposed in the conductive part 120, and inorganic non-metal conductive particles or metal conductive particles may be mixed with the conductive paste to fill the corner positions of the grooves 111 through fluidity of the conductive paste.

The conductive adhesive is an adhesive with certain conductivity after being solidified or dried. The conductive adhesive is provided with conductive particles, and can connect various conductive materials together to form an electric path between the connected materials. Specifically, the conductive particles are present separately in the adhesive before curing or drying, and are not in continuous contact with each other, and thus are in an insulating state. After the conductive adhesive is cured or dried, the volume of the adhesive is contracted due to the volatilization of the solvent and the curing of the adhesive, so that the conductive particles are in a stable continuous state with each other, and thus the conductivity is exhibited. The conductive paste can extend around the groove 111 to fill more positions of the groove 111.

In one aspect, the inorganic nonmetallic conductive particles include at least one of graphene or carbon nanotubes. Carbon Nanotubes (CNTs) are a coaxial, seamless tubular carbon material of nanometer diameter formed by one or more graphite layers rolled up according to a certain helical angle. Carbon nanotubes are generally classified into single-walled carbon nanotubes and multi-walled carbon nanotubes. The carbon nano tube has rich electric transport characteristics, better electric and thermal conductivity, stable chemical performance and capability of effectively improving the physical performance of the main material according to the coincidence of the carbon nano tube and the high polymer material.

Graphene (Graphene) is a material consisting of carbon atoms in sp ² Hybrid track composition sixThe angle type two-dimensional carbon nano material is in honeycomb lattice. The basic characteristics of graphene are high-strength flexibility, heat and electricity conduction and optical properties. Graphene has electron mobility exceeding 15000cm at normal temperature ² Vs, and resistivity of only about 10-6 Ω cm, lower than copper or silver. As one of important applications of graphene, a graphene transparent conductive film exhibits good conductivity, chemical stability, and flexibility.

The metal conductive particles comprise at least one of gold, silver, copper, iron, nickel, tin, or aluminum. Gold, silver, copper, iron, nickel, tin, and aluminum are all capable of achieving electrical conductivity. The properties of the metal conductive particles are close to those of the copper layer 130, and the properties of the inorganic non-metal conductive particles are close to those of the substrate 110, so that the metal conductive particles and the inorganic non-metal conductive particles have certain metal properties and non-metal properties through mixing. The grooves 111 are filled with the mixture of the two materials, one surface of the substrate 110 can be well bonded, and the other surface of the substrate can be well bonded with the copper layer 130. At this time, the conductive portion 120 has adhesion to both the base material 110 and the copper layer 130, and the combination of the base material 110 and the copper layer 130 can be well realized by the cooperation of the conductive adhesive, thereby improving the combination force of the two.

Further, when the conductive portion 120 and the copper layer 130 are both made of the same material, the bonding force between the base material 110 and the copper layer 130 can be improved. The substrate 110 is made of a polymer material, and the copper layer 130 is made of a metal, so that an effective bonding force is difficult to form on the contact surface of the substrate and the copper layer 130, and the contact area between the copper layer 130 and the substrate 110 can be enlarged by providing the grooves 111. Thereby improving the bonding effect of the copper layer 130 and the substrate 110 and reducing the separation between the two.

The conductive portion 120 may be formed by injecting a conductive paste mixed with inorganic nonmetallic conductive particles or metallic conductive particles into the groove 111 in an injection manner when the conductive portion 120 is provided. Conductive particles may be deposited in the grooves 111 by vacuum magnetron sputtering to form the conductive portions 120. Further, it is also conceivable that the conductive portion 120 is formed by ultrasonic spraying (spraying a conductive particle suspension) to move the conductive particles toward the grooves 111 and deposit the conductive particles on the grooves 111 by ultrasonic action on the suspended conductive particles.

The copper layer 130 is relatively thick, and may be electroplated to reduce damage to the substrate 110 by high temperature and high speed particles during the provision of the copper layer 130. Specifically, the composite copper foil further includes a conductive seed layer 140, the conductive seed layer 140 is disposed between the conductive portion 120 and the copper layer 130, and the material of the conductive seed layer 140 is the same as that of the copper layer 130. The conductive seed layer 140 may be disposed by vacuum magnetron sputtering, and the substrate 110 is exposed to the magnetron sputtering environment for a short time due to the thin thickness of the conductive seed layer 140, so that the substrate 110 is not damaged greatly. The thickness of the conductive seed layer 140 is typically between 30nm and 70nm. The thickness of the conductive seed layer 140 may be 30nm, 31nm, 32nm, 33nm, 34nm, 35nm, 36nm, 37nm, 38nm, 39nm, 40nm, 41nm, 42nm, 43nm, 44nm, 45nm, 46nm, 47nm, 48nm, 49nm, 50nm, 51nm, 52nm, 53nm, 54nm, 55nm, 56nm, 57nm, 58nm, 59nm, 60nm, 61nm, 62nm, 63nm, 64nm, 65nm, 66nm, 67nm, 68nm, 69nm, or 70nm. The thickness of the copper layer 130 is between 1um and 2um, and may be 1um, 1.1um, 1.2um, 1.3um, 1.4um, 1.5um, 1.6um, 1.7um, 1.8um, 1.9um, or 2um.

The thickness D of the conductive portion 120 satisfies: d is more than or equal to 0.1um and less than or equal to 0.5um. The thickness of the conductive portion 120 may also be understood as the depth of the recess 111. The thickness of the conductive portion 120 may be 0.1um, 0.2um, 0.3um, 0.4um, or 0.5um.

Referring to fig. 9, the substrate 110 has a first surface 101 and a second surface 102 disposed opposite to each other, the groove 111 disposed on the first surface 101 is a first groove 111a, the groove 111 disposed on the second surface 102 is a second groove 111b, and the first groove 111a and the second groove 111b are staggered with each other. By the mutual staggering of the first grooves 111a and the second grooves 111b, the arrangement of the grooves 111 in the same orthographic projection area of the surface of the substrate 110 is avoided. If the grooves 111 are provided in the same orthographic projection area, the thickness of the base material 110 at that position is likely to be too thin, and if the thickness is too thin, the tear resistance of the base material 110 is likely to be deteriorated, and the composite copper foil is likely to be broken.

Example two

Referring to fig. 10, the present application further provides a method for manufacturing a composite copper foil, where the method for manufacturing a composite copper foil includes:

step S10, providing a substrate 110; the substrate 110 is usually made of a polymer material, and the substrate 110 is used as a basic structure to support the conductive portion 120 and the copper layer 130.

Step S20, providing a groove 111 on the surface of the substrate 110; by means of laser etching, grooves 111 are etched in the surface of the substrate 110. The laser may be controlled to move on the surface of the substrate 110 according to a predetermined movement path, thereby etching the grooves 111 on the surface of the substrate 110. The depth of the grooves 111 can be accomplished by controlling the power of the laser and the etching time.

Step S30, covering the surface of the substrate 110 and exposing the grooves 111, and depositing conductive particles in the grooves 111 to form conductive portions 120; the surface of the substrate 110 is covered by a mask plate in a masking manner, the groove 111 is exposed, and an opening area corresponding to the groove 111 is formed in the mask plate. There are various ways to deposit the conductive portion 120, for example, by vapor deposition. In addition, a mode of injecting conductive adhesive or ultrasonic spraying can be adopted. Among them, magnetron sputtering is one of physical vapor deposition (Physical Vapor Deposition, PVD). Magnetron sputtering bombards the conductive particles out of the target and deposits them into the grooves 111. The magnetron sputtering can be used for preparing multiple materials such as metal, semiconductor, insulator and the like, and has the advantages of simple equipment, easy control, large coating area, strong adhesive force and the like. Magnetron sputtering increases the sputtering rate by introducing a magnetic field at the target cathode surface, and increasing the plasma density by confining the charged particles by the magnetic field.

In step S40, the copper layer 130 is provided on the surface of the substrate 110 provided with the conductive portion 120.

In the technical solution of this embodiment, the substrate 110 is used as a basic structure, the surface of the substrate 110 is provided with the grooves 111 by means of laser etching, and the conductive particles are disposed in the grooves 111 to form the conductive portions 120. The copper layer 130 covers the surface of the substrate 110, and when the copper layer 130 transmits a current, the current can also pass through the conductive portion 120. The cross-sectional area of the current flowing through the conductor at the position of the groove 111 is increased, and the resistance is reduced, so that the heat generation in the composite copper foil can be reduced, the internal overheat condition of the battery is reduced, and the use safety of the battery is ensured.

Referring to fig. 11, the step of disposing a copper layer 130 on the surface of the substrate 110 on which the conductive portion 120 is disposed includes:

step S410, depositing a conductive seed layer 140 on the surface of the substrate 110; the conductive seed layer 140 is made to cover the conductive portion 120. The conductive seed layer 140 may be provided by physical vapor deposition, such as magnetron sputtering. At this time, the mask is removed, and the surface of the substrate 110 and the conductive portion 120 are exposed to the magnetron sputtering environment. Thus, copper ions gradually deposit a conductive seed layer 140 on the surface of the substrate 110 under the action of the magnetic field.

In step S420, the copper layer 130 is formed according to the electroplating of the conductive seed layer 140. The substrate 110 provided with the conductive seed layer 140 is immersed in a solution containing copper ions, and the conductive seed layer 140 is electroplated as a cathode, whereby copper ions are deposited on the surface of the conductive seed layer 140 and cover the conductive seed layer 140. The solution containing copper ions comprises a copper sulfate solution and can also be a copper fluoroborate solution.

Example III

The present application also provides a battery comprising a positive terminal and a negative terminal, the negative terminal comprising a composite copper foil as described above.

The specific embodiments and beneficial effects of the battery are referred to the above-mentioned composite copper foil examples, and are not described herein.

While the present application has been described with reference to several exemplary embodiments, it is understood that the terminology used is intended to be in the nature of words of description and illustration rather than of limitation. As the present application may be embodied in several forms without departing from the spirit or essential attributes thereof, it should be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalences of such metes and bounds are therefore intended to be embraced by the appended claims.

Claims (10)

1. A composite copper foil, characterized in that the composite copper foil comprises:

a substrate, the surface of which is provided with a groove;

the conductive part is arranged in the groove;

and the copper layer is arranged on the surface of the base material and covers the conductive part.

2. The composite copper foil according to claim 1, wherein a plurality of the grooves are provided, and a plurality of the grooves are arranged on the surface of the base material at equal intervals.

3. The composite copper foil of claim 1, wherein the conductive portion comprises at least one of inorganic non-metallic conductive particles or metallic conductive particles.

4. The composite copper foil of claim 3, wherein the inorganic nonmetallic electroconductive particles comprise at least one of graphene or carbon nanotubes;

the metal conductive particles include at least one of gold, silver, copper, iron, nickel, tin, or aluminum.

5. The composite copper foil of claim 1, further comprising a conductive seed layer disposed between the conductive portion and the copper layer, wherein the conductive seed layer is the same material as the copper layer.

6. The composite copper foil according to claim 1, wherein the conductive portion has a thickness D that satisfies the following conditions: d is more than or equal to 0.1um and less than or equal to 0.5um.

7. The composite copper foil according to any one of claims 1 to 6, wherein the substrate has a first surface and a second surface disposed opposite to each other, the first surface being provided with grooves which are first grooves, the second surface being provided with grooves which are second grooves, the first grooves and the second grooves being staggered with each other.

8. The manufacturing method of the composite copper foil is characterized by comprising the following steps of:

providing a substrate;

providing a groove on the surface of the base material;

covering the surface of the substrate and exposing the grooves, and depositing conductive particles in the grooves to form conductive parts;

and a copper layer is arranged on the surface of the base material provided with the conductive part.

9. The method of producing a composite copper foil according to claim 8, wherein the step of providing a copper layer on a surface of a substrate on which the conductive portion is provided comprises:

depositing a conductive seed layer on the surface of the substrate;

and forming the copper layer according to the electroplating of the conductive seed layer.

10. A battery comprising a positive terminal and a negative terminal, the negative terminal comprising the composite copper foil of any one of claims 1-7.

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