TWI792449B - Electrolytic copper foil, and electrode and copper-clad laminate comprising the same - Google Patents

Abstract

Provided are an electrolytic copper foil, and an electrode and a copper-clad laminate comprising the same. The electrolytic copper foil has a temperature coefficient of resistance from 0.0012 K ^-1to 0.0039 K ^-1. With this characteristic, the thermostability of the electrolytic copper foil can be improved, thereby improving the value of subsequent applications.

Description

Electrolytic copper foil, electrode including same, and copper-clad laminate

This creation relates to an electrolytic copper foil, especially an electrolytic copper foil applicable to technical fields such as lithium-ion batteries and printed circuit boards. In addition, the present invention also relates to an electrode and a copper-clad laminate comprising the aforementioned electrolytic copper foil.

Copper foil has good electrical conductivity and has lower cost than precious metals such as silver, so it is not only widely used in basic industries, but also an important raw material for advanced technology industries; for example, copper foil can not only As the conduction material between the components of the circuit board and the basic material of the copper-clad laminate, it is used in the electronic industry such as smart phones and notebook computers. It can also be used as an electrode material for lithium-ion batteries and is used in portable electronic devices. electronic devices, PED), electric vehicles (electric vehicles, EV) and other fields.

As consumers have increasingly stringent requirements for the portability and lightweight of electronic and electrical products, the copper foil used inside is also becoming thinner and thinner. Therefore, the characteristics and quality of copper foil have great influence on the performance of electronic and electrical products. The impact is more pronounced. Since the aforementioned products tend to generate heat during use, if the thermal stability of the copper foil contained therein is not good, the performance of the aforementioned products is likely to be deteriorated, resulting in a shortened service life of the product. For example, if this kind of copper foil with poor thermal stability is used in lithium-ion batteries, it will reduce the cycle characteristics of lithium-ion batteries; if this kind of copper foil with poor thermal stability is used in the process of printed circuit boards, signal transmission may occur Because of the problem of excessive loss, it is necessary to improve the thermal stability of copper foil.

In view of this, the purpose of this creation is to improve the thermal stability of copper foil, so as to improve the quality of its subsequent application products, making it suitable for both lithium-ion batteries and printed circuit boards.

To achieve the aforementioned purpose, the present invention provides an electrolytic copper foil, wherein the temperature coefficient of resistance (referred to as α value) of the electrolytic copper foil is 0.0012 K ⁻¹ to 0.0039 K ⁻¹ .

By regulating the temperature coefficient of resistance of the electrolytic copper foil in an appropriate range, the invention can specifically improve the thermal stability of the electrolytic copper foil, thereby inhibiting or slowing down the deterioration of the electrolytic copper foil due to the heat generated by subsequent products after long-term use. The problem of greatly increasing the internal resistance of electrolytic copper foil, thereby improving the performance of products containing it.

According to the present invention, the temperature coefficient of resistance of the electrolytic copper foil refers to the temperature coefficient of resistance obtained by measuring the electrolytic copper foil after 6 hours of annealing treatment, and the annealing treatment is carried out in an environment with a constant temperature of 110°C. The microstructure of the electrolytic copper foil undergoes annealing treatment will change. The above-mentioned temperature and time are selected because the conditions are used to simulate the parameter conditions of subsequent processes, such as the preparation of lithium-ion batteries or the preparation of printed circuit boards.

According to the invention, the electrolytic copper foil includes a raw foil. In this specification, the raw foil is mainly composed of sulfuric acid and copper sulfate as the electrolyte, an insoluble metal as the anode (dimensionally stable anode, DSA), and a titanium roller with a polished surface as the cathode roller (cathode drum), and a direct current is passed between the two poles to electrodeposit copper ions in the electrolyte on the cathode drum. When the original foil reaches a certain thickness, it is obtained by peeling the original foil from the surface of the cathode roller and continuously winding it; wherein, the surface of the original foil in contact with the surface of the cathode roller is called "roller surface" ( drum side), and the opposite side is called the "deposited side".

In order to improve the anti-rust ability, maintain electrical conductivity, improve the adhesion between copper foil and active materials or dielectric materials, and heat resistance and chemical resistance, the original foil can be properly treated to make the electrolytic copper foil more At least one surface treatment layer is included, and the surface treatment layer is arranged on at least one of the roller surface and the deposition surface of the raw foil. In one embodiment, when the electrolytic copper foil includes a first surface treatment layer, the first surface treatment layer is disposed on one of the deposition surface or the roller surface; in another embodiment , when the electrolytic copper foil includes both the first surface treatment layer and the second surface treatment layer, the original foil is located between the first surface treatment layer and the second surface treatment layer; that is, the first surface treatment layer and the second surface treatment layer can be arranged on the deposition surface and the roller surface respectively, or the first surface treatment layer and the second surface treatment layer can also be arranged on the roller surface and the deposition surface respectively .

According to the present invention, the first surface treatment layer has a first treatment surface opposite to the original foil; the second surface treatment layer has a second treatment surface opposite to the original foil.

It should be noted that the two surfaces of the electrolytic copper foil refer to the two outermost surfaces of the electrolytic copper foil; in one embodiment, when the original foil is not subjected to subsequent surface treatment, the two surfaces of the electrolytic copper foil are The roller surface and the deposition surface of the original foil; in another embodiment, when the deposition surface and the roller surface of the original foil are both surface treated, the two surfaces of the electrolytic copper foil are respectively the first surface treatment layer and the outer surface of the second surface treatment layer, that is, the first treatment surface and the second treatment surface; in yet another embodiment, when the deposition surface is subjected to surface treatment and the roller surface is not subjected to surface treatment, The two surfaces of the electrolytic copper foil are the first treated surface and the roller surface; The surfaces are respectively the first treatment surface and the deposition surface.

According to this creation, without departing from the spirit of this creation, those skilled in the art can implement roughening treatment, copper coating treatment, passivation treatment, antirust treatment, silane coupling on the deposition surface and/or the roller surface according to the needs Any one or two or more surface treatments such as treatment, so that the first surface treatment layer and the second surface treatment layer can independently include a roughening layer, a copper clad layer, a nickel layer, a zinc layer, and an antirust layer , and at least one sublayer in the silane coupling treatment layer, but not limited thereto. The roughening layer, copper clad layer, nickel layer, zinc layer, anti-rust layer, and silane coupling treatment layer can all be collectively referred to as sub-layers. The first surface treatment layer and the second surface treatment layer may be a collection of the same or different sub-layers.

As for the roughening treatment, at least one of the roller surface or the deposition surface may be subjected to roughening treatment as required, and the outer surface of any sublayer may also be subjected to roughening treatment. The surface obtained by the roughening treatment has a fine concave-convex shape, and the shape may be spherical, needle-like, or plate-like, but not limited thereto. The roughening treatment can include a roughening treatment using metal ions such as copper, nickel, chromium, or zinc to conduct a single electrodeposition to form a single-layer roughened layer, or sequentially electrodeposit different types of metal ions The roughening treatment forms a multilayer structure roughening layer; in addition, mechanical abrasion or chemical microetching can also be used for roughening treatment, but not limited thereto.

In some embodiments, without departing from the spirit of the present invention, those skilled in the art may also perform copper cladding treatment on the outer surface of the roughened layer as required, so as to make the first and second surface treatment layers more It further includes a copper clad layer.

As far as passivation treatment is concerned, at least one of the roller surface or the deposition surface of the original foil may be subjected to passivation treatment as required, and the outer surface of any sub-layer may also be subjected to passivation treatment, for example, the roughened layer may be Passivation treatment is performed on the outer surface of or the outer surface of the copper clad layer. Specifically, zinc or zinc alloy can be selected for passivation treatment to obtain the zinc layer in the first and second surface treatment layers; in addition, nickel or nickel alloy can also be selected for passivation treatment to obtain the first , the nickel layer in the second surface treatment layer. The passivation layer obtained through passivation treatment can improve the chemical resistance of the electrolytic copper foil.

As far as antirust treatment is concerned, at least one of the roller surface or the deposition surface of the original foil may be subjected to antirust treatment, and the outer surface of any sublayer may also be subjected to antirust treatment, for example, it can be described in The outer surface of the roughened layer, the outer surface of the copper-clad layer or the outer surface of the passivation layer (such as a zinc layer or a nickel layer) is subjected to anti-rust treatment. Among them, the antirust treatment can include organic antirust treatment using azole compounds (azole), etc., so that the antirust layer is an organic antirust layer; or inorganic antirust treatment using chromium-containing raw materials, etc., to make the antirust layer The layer is an inorganic antirust layer such as a chromium layer. Specifically, the anti-rust treatment can be applied in any known way, for example, methods such as dip coating, spray coating, and electroplating can be used to attach the anti-rust elements to the surface to be applied. As far as azole compounds are concerned, triazole, benzotriazole, tolyltriazole, carboxybenzotriazole, chlorine-substituted benzotriazole (chloro -substituted benzotriazole), 3-amino-1,2,4-triazole (3-amino-1,2,4-triazole), 4-amino-1,2,4-triazole (4-amino- 1,2,4-triazole), or their derivatives and other triazole compounds; thiazole, isothiazole, 2-amino-4-methylthiazole (2-amino-4-methylthiazole ), or their derivatives and other thiazole compounds; and imidazole (imidazole), 1-methyl-2-mercaptoimidazole (2-mercapto-1-methylimidazole), 1-(β-hydroxyethyl)-2- Methylimidazole (1-(2-hydroxyethyl)-2-methylimidazole), 1-(β-chloroethyl)-2-methylimidazole (1-(2-chloroethyl)-2-methylimidazole), 2-amino For imidazole compounds such as benzimidazole (2-aminobenzimidazole) or their derivatives, the organic antirust treatment can also be performed using one or more of the aforementioned azole compounds. As far as chromium-containing raw materials are concerned, it usually refers to the use of chromic acid (chromic (VI) acid), chromium oxide, chromate (chromate) or dichromate (dichromate (VI)) to produce trivalent chromium or hexavalent chromium A chromium-containing feedstock of chromium; in some embodiments, the chromium-containing feedstock is chromium trioxide (CrO ₃ ).

As far as the silane coupling treatment is concerned, at least one of the roller surface or the deposition surface of the original foil can be subjected to silane coupling treatment, and the outer surface of any sublayer can also be subjected to silane coupling treatment. The outer surface of the roughened layer, the outer surface of the copper clad layer, the outer surface of the passivation layer, or the outer surface of the anti-rust layer is subjected to silane coupling treatment, and then the silane coupling treatment in the surface treatment layer is obtained. layer. The silane coupling agent may include, but not limited to, the group represented by the following chemical formula: Y-(R') _n -Si(OR) ₃ , wherein Y is selected from glycidyl (epoxy), amine , epoxycyclohexyl, ureido, urethane, malonate, carboxyl, mercapto, cyano, acetyloxy, acryloxy, methacryloxy, chloromethylbenzene A group consisting of base, pyridyl, vinyl, dialkylamino, phenylalkylamino and imidazolyl; n is an integer of 0 or 1; R' is methyl, ethyl, propyl, or A phenylene group substituted by an ethyl or propyl group, wherein the phenylene ring in the phenylene group is connected to Y; and R is a methyl group, an ethyl group, or a straight-chain or branched chain alkane with 3 to 6 carbons Specifically, the silane coupling agent can use epoxy-based silane, amino-based silane, methacryloxy-based silane, vinyl Silane (vinyl-based silane), mercapto-based silane (mercapto-based silane); silane coupling treatment can also use more than one silane coupling agent.

Preferably, before the surface treatment, the raw foil can be pickled to make the roller surface and deposition surface of the raw foil cleaner, which is helpful for subsequent surface treatment procedures.

According to the present invention, the surface morphology of the electrolytic copper foil is one of the important factors affecting the bonding strength between the electrolytic copper foil and the layer containing active materials or dielectric materials. Preferably, the average height (Rc) of the roughness curve elements of the first treatment surface is 0.34 μm to 9.72 μm. Wherein, Rc is measured according to the JIS B 0601:2013 standard method, which represents the average height of the roughness curve elements on the evaluation length.

Preferably, the Rc of the second treated surface is 0.34 μm to 9.72 μm.

When the Rc of the outer surface of the electrolytic copper foil (that is, the first treatment surface and/or the second treatment surface) is respectively in the aforementioned range, the outer surface of the electrolytic copper foil can provide an appropriate space to accommodate the active material or resin layer, so that The outer surface can provide a better anchor effect, so the electrolytic copper foil can have excellent peel strength.

When the first surface treatment layer includes an anti-rust layer, the Rc of the first treatment surface can be in the aforementioned range; preferably, the Rc of the first treatment surface is 0.34 μm to 1.63 μm; more preferably, the first treatment surface The Rc of the treated surface is 0.39 μm to 1.50 μm. When the second surface treatment layer includes an anti-rust layer, the Rc of the second treatment surface can also be in the aforementioned range; preferably, the Rc of the second treatment surface is 0.34 μm to 1.63 μm; more preferably, the second treatment surface The Rc of the two treated surfaces is 0.39 μm to 1.50 μm.

When the first surface treatment layer includes a roughened layer, the Rc of the first treatment surface can be in the aforementioned range; preferably, the Rc of the first treatment surface is 0.38 μm to 9.72 μm; more preferably, the first treatment surface The Rc of the treated surface is 0.42 μm to 8.91 μm. When the second surface treatment layer includes a roughened layer, the Rc of the second treatment surface can be in the aforementioned range; preferably, the Rc of the second treatment surface is 0.38 μm to 9.72 μm; more preferably, the second treatment surface The Rc of the treated surface is 0.42 μm to 8.91 μm.

Generally speaking, in addition to the source of copper ions, other organic additives, ions or current density used in the electrolyte may affect the current distribution, the copper foil deposition thickness distribution during electrolysis, and then affect the obtained The surface properties of the original foil. Specifically, the organic additive can be sulfur-containing compounds with mercapto group, disulfide or sulfonate, low molecular weight gel, hydroxyethyl cellulose (HEC ) or polyethylene glycol (polyethylene glycol, PEG), but not limited thereto; Mercapto-1-propanesulfonic acid sodium salt (3-mercapto-1-propanesulfonic acid sodium salt, MPS), N,N-dimethyldithioamide propanesulfonate (3-N,N-dimethylaminodithiocarbamoyl-1 -propanesulfonic acid sodium salt, DPS), 3-thio-isothiourea propyl sulfonic acid (3-(amidinothio)-1-propanesulfonic acid, UPS) or 3-(benzothiazole-2 mercapto)propanesulfonic acid sodium salt (3-(benzothiazolyl-2-mercapto)-propyl-sulfonic acid, sodium salt, ZPS), but not limited thereto. For example, the low molecular weight gel may include gelatin, but is not limited thereto. Specifically, the ions can be chromium (Cr), tungsten (W), silver (Ag), cerium (Ce), molybdenum (Mo), titanium (Ti), nickel (Ni), zinc (Zn), cobalt ( Co), tellurium (Te) ions, but not limited thereto.

The invention further provides an electrode for a lithium-ion battery, which includes the aforementioned electrolytic copper foil, at least one adhesive, and at least one active material. The electrolytic copper foil is suitable for use as a collector, and one or both sides of the electrolytic copper foil are coated with one or more active materials including active substances and binders to form electrodes. The electrode can be used as a negative electrode of a lithium ion battery or as a positive electrode; preferably, the electrode is a negative electrode.

Specifically, the adhesive may include polyvinylidene fluoride (poly-1,1-difluoroethene, PVDF), polyacrylic acid (poly(acrylic acid)), carboxymethyl cellulose (carboxymethyl cellulose, CMC), styrene Butadiene rubber (Styrene butadiene rubber, SBR), polyimide (polyimide, PI), polyvinyl alcohol (poly vinyl alcohol, PVA) or a combination thereof, but not limited thereto.

The active material can enable the electrode to obtain good cycle characteristics; for example, the active material can be a carbon-containing material, a silicon-containing material, a silicon-carbon composite, a metal, a metal oxide, a metal alloy or a polymer, among which preferably It is a carbon-containing substance or a silicon-containing substance, but not limited thereto. Specifically, the carbonaceous substance may be non-graphitizing carbon, coke, graphite, glasslike carbon, carbon fiber, activated carbon ), carbon black (carbon black) or high-polymer calcined products, but not limited thereto; wherein, coke includes pitch coke, needle coke or petroleum coke, etc.; phenol-formaldehyde resin) or furan resin (furan resin) and other high polymers to be obtained by carbonation. The silicon-containing substance has an excellent ability to form an alloy with lithium ions and an excellent ability to extract lithium ions from the alloy lithium. Moreover, when the silicon-containing substance is used to form a lithium-ion secondary battery, a secondary battery with a large energy density can be realized. Batteries; silicon-containing substances can be combined with cobalt (Co), iron (Fe), tin (Sn), nickel (Ni), copper (Cu), manganese (Mn), zinc (Zn), indium (In), silver (Ag ), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb), chromium (Cr), ruthenium (Ru), molybdenum (Mo) or combinations thereof to form an alloy material. The elements of the metal or metal alloy may be selected from the group consisting of cobalt, iron, tin, nickel, copper, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, chromium, ruthenium and molybdenum , but not limited to this. Examples of the metal oxide are ferric oxide, ferric oxide, ruthenium dioxide, molybdenum dioxide, and molybdenum trioxide, but are not limited thereto. Examples of such polymers are polyacetylene and polypyrrole, but not limited thereto.

In addition, without affecting the effect of the electrode used in lithium-ion batteries of this creation, other auxiliary additives can be added to the electrode, such as lithium hydroxide (LiOH), oxalic acid (H ₂ C ₂ O ₄ ), etc., but not limited to this.

According to the invention, the electrode can be applied to lithium-ion batteries, and the lithium-ion batteries are suitable for electronic devices such as mobile power supplies, smart phones, notebook computers, electric vehicles, etc., but not limited thereto.

The invention further provides a copper-clad laminate, which includes the aforementioned electrolytic copper foil and a resin substrate. The copper-clad laminate can also be applied to the fields of printed circuit boards such as rigid copper foil substrates, flexible copper foil substrates, and IC substrates, but is not limited thereto.

Specifically, the material of the resin substrate may be polyimide resin, epoxy resin, polyethylene terephthalate resin, liquid crystal polymer, etc., but is not limited thereto.

Below, several examples are cited to illustrate the implementation of the electrolytic copper foil, lithium-ion battery, and copper-clad laminate of the present invention, and several comparative examples are provided as a comparison. Those skilled in the art can learn from the following examples and comparative examples The content makes it easy to understand the advantages and effects that this creation can achieve. It should be understood that the examples listed in this specification are only used to illustrate the implementation of the invention, and are not intended to limit the scope of the invention. Those skilled in the art can use their common knowledge without departing from the spirit of the invention. Various modifications and changes are made to implement or apply the content of this creation.

《Electrolytic Copper Foil》

Example 1 to 4 : Electrolytic copper foil

Examples 1 to 4 used the production equipment shown in FIG. 1 , and sequentially produced electrodeposited copper foils through substantially the same electrodeposition steps and surface treatment steps. Examples 1 to 4 differ mainly in the composition of the electrolyte and the current density in the electrodeposition step.

As shown in Figure 1, the equipment for producing electrolytic copper foil includes an electrodeposition device 10, a series of guide rollers 20, and a surface treatment device 30; the electrodeposition device 10 includes a cathode roller 11, an anode plate 12, and a copper electrolyte 13 And feed pipe 14. The cathode roller 11 is rotatable, and the anode plate 12 is arranged along the arc of the lower half of the cathode roller 11 . The cathode roller 11 and the anode plate 12 are spaced apart from each other to accommodate the copper electrolyte 13 fed through the feed pipe 14 . The surface treatment device 30 includes an anti-rust treatment tank 31 and two sets of first pole plates 311a, 311b arranged therein; a series of guide rollers 20 include a first guide roller 211, a second guide roller 212, a third guide roller 213, Air knife (air knife) 22 and winding wheel 23 can be used to transport the electrodeposited raw foil 41 , surface-treated copper foil and finished products, and finally wind up the electrolytic copper foil 40 on the winding wheel 23 .

Using the equipment for producing electrolytic copper foil shown in FIG. 1 , the methods for manufacturing the electrolytic copper foil 40 of Examples 1 to 4 are collectively described below.

First, prepare the copper electrolyte solution 13 for the electrodeposition step as follows: 1. Basic solution: (1) Copper sulfate (CuSO ₄ ‧5H ₂ O): 305 grams/liter (g/L), (2) Sulfuric acid: 105 g/L; 2. Additions: (1) Chloride ion (from hydrochloric acid, purchased from RCI Labscan Ltd.): 27 mg/L (mg/L); (2) Gelatin (DV, purchased from Nippi Inc.): 4.5 mg/L; (3) ZPS: 2.0 mg/L to 10 mg/L; (4) Chromium ion (from H ₂ CrO ₄ or CrO ₃ ): 30 mg/L to 130 mg /L;

During the electrodeposition step, the temperature of the copper electrolyte solution 13 is controlled to be 45°C, and a current density of 45 amps/square decimeter (A/dm ² ) is applied to the cathode roller 11 and the anode plate 12, The copper ions in the copper electrolyte 13 are deposited on the surface of the cathode roller 11 to form the original foil 41 , and then the original foil 41 is peeled off from the cathode roller 11 and guided to the first guide roller 211 .

Table 1 lists the content ratios of ZPS and chromium ions in the copper electrolytic solution 13 used in manufacturing the electrolytic copper foil 40 of Examples 1 to 4, and the applied current density.

Anti-rust treatment

Subsequently, the original foil 41 is transported to the surface treatment device 30 by the first guide roller 211 for antirust treatment: the original foil 41 is immersed in the antirust treatment tank 31 filled with chromium antirust solution, and the two sets of first poles The plates 311a, 311b subject the roll side and the deposition side of the raw foil 41 to electrodeposition steps respectively to form surface treatment layers attached to the deposition side and the roll side.

Here, the formula of chromium antirust solution and the process conditions of antirust treatment are as follows: 1. Formula of chromium antirust solution: chromic acid (CrO ₃ ): 1.5 g/L; 2. Process conditions: (1) Chromium antirust Liquid temperature: 25°C; (2) Current density: 0.5 A/dm ² ; (3) Processing time: 2 seconds (sec).

After the anti-rust treatment is completed under the above conditions, guide the anti-rust treated copper foil to the second guide roller 212 and use the air knife 22 to dry it, and then transfer it to the winding wheel 23 by the third guide roller 213 The electrolytic copper foil 40 was obtained by winding up.

Electrodeposited copper foils 40 of Examples 1 to 4 can be produced according to the above-mentioned manufacturing method. As shown in Figure 2, the electrolytic copper foil 40 of each embodiment includes the original foil 41 and two surface treatment layers 42; wherein, the original foil 41 includes the opposite deposition surface 411 and the roller surface 412, and these surface treatment layers 42 include the second A surface treatment layer 42a (i.e. the first chromium layer) and a second surface treatment layer 42b (i.e. the second chromium layer); the first surface treatment layer 42a is directly covered on the deposition surface 411 of the original foil 41, and the second surface treatment layer The layer 42b then covers directly the roll face 412 of the raw foil 41 . The first surface treatment layer 42a has a first treatment surface 42a' opposite to the deposition surface 411, and the first treatment surface 42a' is the outer surface of the first chromium layer; the second surface treatment layer 42b has a surface opposite to the deposition surface 411. The second treated surface 42b' of the roller surface 412 is the outer surface of the second chrome layer.

comparative example 1 to 7 : Electrolytic copper foil

Comparative Examples 1 to 7 are used as the contrast of Examples 1 to 4, which adopt a method similar to the preparation method of Examples 1 to 4 to produce electrolytic copper foil, the difference mainly lies in the content ratio of ZPS and chromium ions in the copper electrolyte (ZPS : 0.8 mg/L to 15 mg/L; Chromium: 15 mg/L to 150 mg/L), and the applied current density (30 A/dm ² to 75 A/dm ² ) are listed in Table 1 ; In addition, the structure of the electrolytic copper foil of Comparative Examples 1 to 7 is also shown in FIG. 2 .

Example 5 to 7 : Electrolytic copper foil

In Examples 5 to 7, the production equipment shown in FIG. 3 was used, and the electrodeposited copper foils were produced through substantially the same electrodeposition steps and surface treatment steps in sequence. The difference between Examples 5 to 7 mainly lies in the process conditions of the surface treatment step and the surface on which the surface treatment is applied.

As shown in Figure 3, the equipment for producing electrolytic copper foil includes an electrodeposition device 10, a series of guide rollers 20, and a surface treatment device 30; the electrodeposition device 10 includes a cathode roller 11, an anode plate 12, and a copper electrolyte 13 And feed pipe 14. The anode plate 12 is arranged along the arc shape of the lower half of the cathode roller 11 , and the cathode roller 11 and the anode plate 12 are spaced apart from each other to accommodate the copper electrolyte 13 fed through the feed pipe 14 . The surface treatment device 30 includes a pickling tank 32, a roughening treatment tank 33 and a group of second pole plates 331 disposed therein, a copper clad treatment tank 34 and a group of third pole plates 341 disposed therein, and a nickel plating tank 35 and a group of fourth pole plates 351 disposed therein, a galvanized tank 36 and two groups of fifth pole plates 361a and 361b disposed therein, a chrome-plated tank 37 and two groups of sixth pole plates 371a and 371b disposed therein, Silane coupling agent spraying device 38, and oven 39; A series of guide rollers 20 include first guide roller 211, second guide roller 212, third guide roller 213, fourth guide roller 214, fifth guide roller 215, sixth guide roller The guide roller 216, the seventh guide roller 217 and the winding wheel 23 can be used to transport the electrodeposited raw foil 41, the copper foil and the finished product after various surface treatment procedures, and finally wind up on the winding wheel 23 to obtain electrolytic foil. Copper foil 40.

Using the equipment for producing electrolytic copper foil 40 shown in FIG. 3, the methods for manufacturing the electrolytic copper foils of Examples 5 to 7 are collectively described below.

Electrodeposition step

Embodiments 5 to 7 all carry out the same electrodeposition step, control the temperature of the copper electrolyte 13 to be 45°C, and apply a current density of 45 A/dm on the cathode roller 11 and the anode plate ¹² , so that the copper The copper ions in the electrolyte 13 are deposited on the surface of the cathode roller 11 to form the original foil 41, and then the original foil 41 is peeled off from the cathode roller 11 and guided to the first guide roller 211; wherein, the formula of the copper electrolyte 13 Identical to the formula adopted in Example 4.

Surface treatment steps

Since the surface treatment steps of Examples 5 to 7 are slightly different, the surface treatment steps adopted in each example are described below.

Example 5 electrolytic copper foil

The electrolytic copper foil manufacturing process of Production Example 5 additionally includes the following seven surface treatment procedures, and the process conditions of each surface treatment procedure are as follows:

I. Pickling treatment : the original foil 41 of embodiment 5 is transported in the pickling tank 32 by the first guide roller 211, and the two surfaces of the original foil 41 are cleaned by immersing the original foil 41 in the pickling solution; wherein, the pickling solution The formulation and process conditions are as follows: 1. The formulation of pickling solution: (1) Copper sulfate (CuSO ₄ ‧5H ₂ O): 200 g/L, (2) Sulfuric acid: 100 g/L; 2. Process conditions: (1) Pickling solution temperature: 25°C; (2) Processing time: 5 sec.

After being processed through the above steps, the pickled raw foil is guided to the second guide roller 212 and then transported to the roughening treatment tank 33 . Referring to FIG. 4A , in this embodiment, the pickled raw foil 41 includes a deposition surface 411 and a roller surface 412 opposite to each other.

II. Roughening treatment : immerse the pickled original foil in the roughening solution in the roughening treatment tank 33, and apply an electrodeposition step to the deposition surface 411 through the second electrode plate 331 to form an adhesion on the deposition surface 411 The roughening layer 421; wherein, the formulation and process conditions of the roughening solution are as follows: 1. The formulation of the roughening solution: (1) Copper sulfate (CuSO ₄ ‧5H ₂ O): 150 g/L, (2) Sulfuric acid: 100 g/L; 2. Process conditions: (1) Roughening solution temperature: 25°C; (2) Current density: 40 A/dm ² ; (3) Processing time: 10 sec.

After being processed through the above steps, the roughened copper foil is guided to the third guide roller 213 and transported to the copper clad treatment tank 34 .

III. Copper cladding treatment : immerse the roughened copper foil in the copper cladding liquid in the copper cladding treatment tank 34, and apply an electrodeposition step to the roughened layer 421 by the third plate 341 to form a copper clad layer 422; Among them, the formula and process conditions of the copper cladding solution are as follows: 1. The formula of the copper cladding solution: (1) copper sulfate (CuSO ₄ ‧5H ₂ O): 220 g/L, (2) sulfuric acid: 100 g/L; 2 . Process conditions: (1) Copper cladding solution temperature: 40°C; (2) Current density: 15 A/dm ² ; (3) Processing time: 10 sec.

After being processed by the above steps, the copper-clad copper foil is guided to the fourth guide roller 214 and transported to the nickel plating tank 35 .

IV. Nickel plating treatment : immerse the copper clad copper foil in the nickel electrolyte in the nickel plating bath 35, and apply an electrodeposition step to the copper clad layer 422 by the fourth pole plate 351 to form a nickel layer 423; wherein, The formulation and process conditions of the nickel electrolyte are as follows: 1. The formulation of the nickel electrolyte: (1) Nickel sulfate (NiSO ₄ ‧6H ₂ O): 170 g/L to 200 g/L, (2) Boric acid (H ₃ BO ₃ ): 20 g/L to 40 g/L; 2. Process conditions: (1) Nickel electrolyte temperature: 20°C; (2) Current density: 0.5 A/dm ² ; (3) Processing time: 10 sec .

After being processed by the above steps, the nickel-plated copper foil is guided to the fifth guide roller 215 and transported to the galvanizing tank 36 .

V. Galvanizing treatment : the nickel-plated copper foil is immersed in the zinc electrolyte in the galvanizing tank 36, and the nickel layer 423 and the roller surface 412 are subjected to electrodeposition steps by two sets of fifth pole plates 361a and 361b , and form the first zinc layer 424a and the second zinc layer 424b on the nickel layer 423 and the roller surface 412 respectively; wherein, the formula and process conditions of the zinc electrolyte are as follows: 1. The formula of the zinc electrolyte: (1) sulfuric acid Zinc (ZnSO ₄ ‧7H ₂ O): 5 g/L to 15 g/L, (2) Ammonium metavanadate (NH ₄ VO ₃ ): 0.1 g/L to 0.4 g/L; 2. Process conditions: ( 1) Zinc electrolyte temperature: 20°C; (2) Current density: 0.5 A/dm ² ; (3) Processing time: 10 sec.

After being processed through the above steps, the galvanized copper foil is guided to the sixth guide roller 216 and transported to the chrome plating tank 37 .

VI. Chromium plating treatment : immerse the galvanized copper foil in the chromium electrolyte in the chrome plating tank 37, and apply a coating to the opposite first zinc layer 424a and second zinc layer 424b by two sets of sixth pole plates 371a and 371b. Electrodeposition step, and form the first chromium layer 425a, the second chromium layer 425b on these zinc layers respectively; Wherein, the recipe of chromium electrolytic solution and process conditions are as follows: 1. The recipe of chromium electrolytic solution: chromic acid (CrO ₃ ): 1.6 g/L to 1.8 g/L; 2. Process conditions: (1) Chromium electrolyte temperature: 45°C; (2) Current density: 2.7 A/dm ² ; (3) Processing time: 10 sec.

After being processed by the above steps, the chrome-plated copper foil is guided to the seventh guide roller 217 .

VII. Silane coupling treatment : the chrome-plated copper foil is guided by the seventh guide roller 217 to the winding wheel 23, and the silane coupling agent solution is sprayed onto the surface of the first chromium layer 425a by the silane coupling agent spraying device 38, To form the silane coupling treatment layer 426 attached to the first chromium layer 425a; wherein, the formulation and process conditions of the silane coupling agent solution are as follows: 1. The formulation of the silane coupling agent solution: (3-glycidoxypropyl) Trimethoxysilane (the product model is KBM 403): 0.25 weight percent (wt%) aqueous solution; 2. Process conditions: Processing time: 10 sec.

After the seven surface treatment procedures are completed under the above conditions, the silane-coupling-treated copper foil is guided to the oven 39 for drying, and then sent to the winding wheel 23 for winding, and finally the electrolytic copper foil 40 is obtained.

As shown in FIG. 4A , the electrolytic copper foil 40 of Example 5 includes an original foil 41 , a first surface treatment layer 42 a and a second surface treatment layer 42 b. Wherein, the raw foil 41 includes a deposition surface 411 and a roller surface 412 opposite to each other. The first surface treatment layer 42a is disposed on the deposition surface 411, and includes a roughened layer 421, a copper clad layer 422, a nickel layer 423, a first zinc layer 424a, a first chromium layer 425a, and a silane coupling treatment layer 426 in sequence; The first surface treatment layer 42 a has a first treatment surface 42 a ′ opposite to the deposition surface 411 , and the first treatment surface 42 a ′ is the outer surface of the silane coupling treatment layer 426 . The second surface treatment layer 42b is disposed on the roller surface 412, and includes a second zinc layer 424b and a second chromium layer 425b in sequence; the second surface treatment layer 42b has a second treatment surface 42b opposite to the roller surface 412 ', the second treated surface 42b' is the outer surface of the second chrome layer 425b.

Example 6 electrolytic copper foil

The preparation method used to prepare the electrolytic copper foil of Example 6 is similar to the method for preparing the electrolytic copper foil of Example 5, the only difference being that the current density in the roughening step in Example 6 is adjusted to 50 A/dm ² . The structure of the obtained electrodeposited copper foil of Example 6 is also shown in FIG. 4A .

Example 7 electrolytic copper foil

The preparation method used to prepare the electrolytic copper foil of Example 7 is similar to the method for preparing the electrolytic copper foil of Example 5, the only difference is that in Example 7, the surface of the roller 412 of the original foil is roughened, galvanized Then the nickel layer 423 and the deposition surface 411 are treated.

As shown in FIG. 4B , the electrolytic copper foil 40 of Example 7 includes an original foil 41 , a first surface treatment layer 42 a and a second surface treatment layer 42 b. Wherein, the raw foil 41 includes a deposition surface 411 and a roller surface 412 opposite to each other. The first surface treatment layer 42a is disposed on the roller surface 412, and sequentially includes a roughened layer 421, a copper clad layer 422, a nickel layer 423, a first zinc layer 424a, a first chromium layer 425a, and a silane coupling treatment layer 426; The first surface treatment layer 42a has a first treatment surface 42a' opposite to the roller surface 412, and the first treatment surface 42a' is the outer surface of the silane coupling treatment layer 426; the second surface treatment layer 42b is disposed on the deposition surface 411, including a second zinc layer 424b and a second chromium layer 425b in sequence; the second surface treatment layer 42b has a second treatment surface 42b' opposite to the deposition surface 411, and the second treatment surface 42b' is the second The outer surface of the chrome layer 425b.

comparative example 8 and 9 : Electrolytic copper foil

Comparative Examples 8 and 9 are used as the comparison of Example 5. The original foil of the electrolytic copper foil is produced in a manner similar to the preparation method of Example 5, and the subsequent seven surface treatment procedures are also used. The difference is mainly in the preparation of the original foil. The content ratios of ZPS and chromium ions in the copper electrolyte are listed in Table 1; in addition, the structures of the electrolytic copper foils of Comparative Examples 8 and 9 are also shown in FIG. 4A.

analyze 1 : Average thickness of electrolytic copper foil

Each of the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 9 was cut into a sample whose length and width were 100 millimeters (mm), and a microbalance (available from AG-204 manufactured by Mettler Toledo Co., Ltd.) ) to measure the weight of the sample; and then divide the weighed weight by the area of the sample to obtain the weight per unit area of each electrolytic copper foil. Next, according to the IPS-TM-650 2.4.18 standard method, the density of the electrolytic copper foil is 8.909 grams/cubic centimeter (g/cm ³ ) (ie 8.909*10 ⁶ g/m ³ ), according to formula (I) The average thickness of the electrodeposited copper foils of Examples 1 to 7 and Comparative Examples 1 to 9 was calculated, and the analysis results of the average thickness of the electrodeposited copper foils of Examples 1 to 7 and Comparative Examples 1 to 9 are listed in Table 1. Average thickness (μm) = weight per unit area (g/m ² )/density of electrolytic copper foil (g/m ³ ) (I)

Table 1 serial number Current density (A/dm ² ) ZPS content ratio (mg/L) Chromium ion content (mg/L) Average thickness (μm) Example 1 45 3.5 30 6 Example 2 45 3.5 130 6 Example 3 45 2 30 6 Example 4 45 10 30 6 Example 5 45 10 30 35 Example 6 45 10 30 35 Example 7 45 10 30 35 Comparative example 1 30 3.5 30 6 Comparative example 2 75 3.5 30 6 Comparative example 3 45 3.5 15 6 Comparative example 4 45 3.5 150 6 Comparative Example 5 45 0.8 30 6 Comparative example 6 45 15 30 6 Comparative Example 7 45 3.5 30 6 Comparative Example 8 45 15 30 35 Comparative Example 9 45 3.5 140 35

analyze 2 : Temperature coefficient of resistance of electrolytic copper foil

The electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 9 were cut to appropriate sizes and then placed in an environment of normal pressure and kept at 110°C for annealing treatment for 6 hours to obtain Examples 1 to 7 and Comparative Examples 1 to 9 samples. Next, measure the resistance values of each sample at 10°C and 50°C respectively with a metal fine wire probe resistance measuring system, and calculate the values of Examples 1 to 7 and Comparative Example by formula (II) The temperature coefficients of resistance of the electrolytic copper foils of 1 to 9, and the analysis results of the temperature coefficients of resistance of the electrolytic copper foils of Examples 1 to 4 and Comparative Examples 1 to 7 are listed in Table 2. In addition, Examples 5 to 7, The analysis results of the temperature coefficient of resistance of the electrodeposited copper foils of Comparative Examples 8 and 9 are listed in Table 3. The relevant test conditions are described as follows: α (K ^-1 ) =[R _323K – R _283K (ohm, Ω)] / [R _50°C (Ω) x (323 K – 283 K)] (II) 1. Thin metal wire Wire probe resistance measurement system: LSR4-TG2L purchased from KeithLink Technology Co., Ltd.; 2. Electrolytic copper foil sample size: 100 mm (length) x 100 mm (width); 3. Test temperature: before 10° C (283 K) was held for 1 hour for measurement, and then heated to 50°C (323K) for 1 hour for measurement.

analyze 3 : Surface roughness of electrolytic copper foil

The surface roughness of the electrodeposited copper foils of Examples 1 to 7 and Comparative Examples 1 to 9 was analyzed with a surface roughness meter. According to the method stipulated in JIS B 0601:2013, the Rc of the first surface treatment layer of these electrolytic copper foils was measured respectively, and the experimental results of the electrolytic copper foils of Examples 1 to 4 and Comparative Examples 1 to 7 are listed in Table 2, the experimental results of the electrodeposited copper foils of Examples 5 to 7 and Comparative Examples 8 and 9 are listed in Table 3. In addition, the relevant test conditions are recorded as follows: 1. Electrolytic copper foil sample size: 100 mm (length) x 100 mm (width); 2. Surface roughness meter: purchased from SE600 manufactured by Kosaka Laboratory Co., Ltd.; 3. Radius of stylus tip: 2 μm; 4. The angle of the tip of the stylus: 90°; 5. Scanning speed: 0.5 mm/sec; 6. Filter cut-off value: 0.8 mm (λc), 2.5 μm (λs); 7. Evaluation length: 4 mm.

"Electrodes for Lithium Ion Batteries, and Lithium Ion Batteries Containing Them"

The first surface treatment layer of the electrolytic copper foil of the aforementioned Examples 1 to 4 and Comparative Examples 1 to 7 is further coated with negative electrode slurry, and after being dried, it is rolled by a rolling machine to produce Example 1- The electrodes of A to 4-A and Comparative Examples 1-A to 7-A, the aforementioned electrodes can be used as negative electrodes of lithium ion batteries. Wherein, 100 parts by weight of the negative electrode active material and 60 parts by weight of N-methylpyrrolidone (1-Methyl-2-pyrrolidone, NMP) are used to form the negative electrode slurry, and the formulation and process conditions of the negative electrode active material are as follows: 1. The formula of the negative electrode active material: (1) Mesophase Graphite Powder (MGP): 93.9 wt%; (2) Conductive additive: conductive carbon black (Super P ^® ): 1 wt%; (3) Solvent-based binder: polyvinylidene fluoride (PVDF 6020): 5 wt%; (4) oxalic acid: 0.1 wt%. 2. Process conditions: (1) Coating rate: 5 meters per minute (m/min); (2) Coating thickness: 200 μm; (3) Drying temperature: 160°C; (4) Roller Material, size and hardness of rolling rollers: high carbon chromium bearing steel (SUJ2); 250 mm × 250 mm; 62 to 65HRC; (5) Rolling speed and pressure: 1 m/min; 3000 pounds per square inch ( psi).

Each of the above-prepared negative electrodes was further matched with the positive electrode, and then a lithium-ion battery comprising the electrodes of Examples 1-A to 4-A and Comparative Examples 1-A to 7-A was prepared.

Specifically, the positive electrode of the lithium-ion battery can be generally prepared through the following steps.

The positive electrode slurry is coated on the aluminum foil, and then rolled with a rolling machine after the solvent evaporates to obtain the positive electrode. Wherein, 100 parts by weight of the positive electrode active material and 195 parts by weight of NMP are used to form the positive electrode slurry, and the formula of the positive electrode active material is as follows: 1. The positive electrode active material: lithium cobalt oxide (LiCoO ₂ ): 89 wt%; 2 . Conductive additives: (1) Flaked graphite (KS6): 5 wt%; (2) Conductive carbon black powder (Super P ^® ): 1 wt%; 3. Solvent-based binder: polyvinylidene fluoride Ethylene (PVDF 1300)): 5 wt%.

Subsequently, the positive electrode and the electrodes of Examples 1-A to 4-A and Comparative Examples 1-A to 7-A are cut to a specific size, and then the positive electrode and each negative electrode are sandwiched between the microporous isolation Membranes (model Celgard 2400, manufactured by Celgard) are stacked alternately, placed in a press-fit mold (model LBC322-01H, purchased from Shenzhen Xinzhoubang Technology Co., Ltd.) filled with electrolyte, and sealed to form a laminated lithium-ion battery , that is, the lithium ion batteries of Examples 1-B to 4-B and Comparative Examples 1-B to 7-B. The size of the laminated lithium-ion battery is 41 mm×34 mm×53 mm.

analyze 4 : Cycle Life Analysis of Li-ion Batteries

In this analysis, the lithium-ion batteries of Examples 1-B to 4-B and Comparative Examples 1-B to 7-B were selected as samples to be tested, and a charge-discharge cycle test was performed. The analysis conditions of the specific charge-discharge cycle test are as follows: 1. Charging mode: constant current-constant voltage (CCCV) (1) Charging voltage: 4.2 volts (V); (2) Charging current: 5C; 2. Discharge mode: constant current (CC) (1) Discharge voltage: 2.8 V; (2) Discharge current: 5C; (3) Test temperature: 55°C.

After the lithium-ion battery as the sample to be tested undergoes repeated charge-discharge cycles, when its capacity drops to 80% of the initial capacity, the number of charge-discharge cycles performed is defined as the cycle life of the lithium-ion battery. The lithium-ion batteries of Examples 1-B to 4-B (respectively comprising the electrolytic copper foils of Examples 1-4) and the lithium-ion batteries of Comparative Examples 1-B to 7-B (respectively comprising the electrolytic copper foils of Comparative Examples 1-7 Copper foil) charge-discharge cycle test results are also listed in Table 2.

Table 2 Electrolytic copper foil Lithium Ion Battery serial number alpha value Rc of the first treatment surface Electrode No. battery number cycle life Example 1 0.0014 K ^-1 0.71 μm Example 1-A Example 1-B 1403 times Example 2 0.0039 K ^-1 0.39 μm Example 2-A Example 2-B 1312 times Example 3 0.0012 K ^-1 1.63 μm Example 3-A Example 3-B 957 times Example 4 0.0027 K ^-1 0.34 μm Example 4-A Example 4-B 1048 times Comparative example 1 0.0052 K ^-1 0.43 μm Comparative Example 1-A Comparative Example 1-B 680 times Comparative example 2 0.0064 K ^-1 1.93 μm Comparative Example 2-A Comparative Example 2-B 643 times Comparative example 3 0.0008 K ^-1 1.01 μm Comparative Example 3-A Comparative Example 3-B 714 times Comparative example 4 0.0052 K ^-1 0.20 μm Comparative Example 4-A Comparative Example 4-B 637 times Comparative Example 5 0.0007 K ^-1 2.02 μm Comparative Example 5-A Comparative Example 5-B 611 times Comparative example 6 0.0064 K ^-1 0.29 μm Comparative Example 6-A Comparative Example 6-B 621 times Comparative Example 7 0.0041 K ^-1 0.24 μm Comparative Example 7-A Comparative Example 7-B 641 times

"Copper Clad Laminated Board"

The electrodeposited copper foils of Examples 5 to 7 and Comparative Examples 8 and 9 faced a resin substrate (purchased from S7439G manufactured by Shengyi Technology Co., Ltd.) with the first surface treatment layer to form a symmetrical stripline structure. samples to obtain the copper-clad laminates of Examples 5-A to 7-A, Comparative Examples 8-A and 9-A.

analyze 5 : Analysis of signal transmission loss of copper clad laminates

In this analysis, the copper-clad laminates of Examples 5-A to 7-A and Comparative Examples 8-A and 9-A will be selected as the samples to be tested. The specific conditions of the samples to be tested are as follows: 1. Dielectric material (that is, the resin substrate): (1) Thickness: 152.4 μm; (2) Dielectric constant (Dk): The Dk value of the dielectric material at a frequency of 10 GHz was measured by the standard method IPC-TM-650 No. 2.5.5.5, and the result was 3.74; (3) Dielectric loss (Df): The Df value of the dielectric material at a frequency of 10 GHz was measured by the standard method IPC-TM-650 No. 2.5.5.5, and the result was 0.006; 2. Conductor (that is, the electrolytic copper foil): (1) Length: 100mm; (2) Thickness: 35 μm; 3. Characteristic impedance: 50 Ω; 4. Status: No cover film.

The signal transmission loss of these copper clad laminates was analyzed with a network analyzer, and the analysis results are listed in Table 3. The specific test conditions are as follows: 1. Instrument model: PNA N5227B purchased from Keysight Technologies; 2. Scanning frequency range: 8 GHz; 3. Scanning points: 2000 points; 4. Calibration method: E-Cal (calibration kit: N4692D); 5. Test method: Cisco S3 method.

If the absolute value of the signal transmission loss of the copper-clad laminate at a frequency of 8 GHz is less than 0.75 decibels per inch (dB/in), it is recorded as "Class A", and if the copper-clad laminate is at a frequency of 8 GHz If the absolute value of the signal transmission loss of the copper-clad laminate is greater than or equal to 0.75 dB/in to less than or equal to 0.8 dB/in, it will be recorded as "Class B". If the absolute value of the signal transmission loss of the copper-clad laminate at a frequency of 8 GHz If it is greater than 0.8 dB/in, it is recorded as "Class C". table 3 Electrolytic copper foil copper clad laminate serial number alpha value Rc of the first treatment surface serial number signal transmission loss Example 5 0.0028 K ^-1 0.38 μm Example 5-A Grade A Example 6 0.0027 K ^-1 9.72 μm Example 6-A Grade B Example 7 0.0028 K ^-1 1.07 μm Example 7-A Grade A Comparative Example 8 0.0065 K ^-1 0.37 μm Comparative Example 8-A Grade C Comparative Example 9 0.0041 K ^-1 0.27 μm Comparative Example 9-A Grade C

"Experimental Results Discussion"

According to the results in Table 2, because the electrolytic copper foils of Examples 1 to 4 control the temperature coefficient of resistance of the electrolytic copper foils in an appropriate range (that is, the α value is 0.0012 K ^-1 to 0.0039 K ^-1 ), therefore, the inclusion of Example 1 The lithium-ion batteries 1-B to 4-B with the electrodes of -A to 4-A can reach more than 900 times in terms of charge and discharge cycle life. It can be proved that the electrolytic copper foil of the present invention can indeed improve the thermal stability, thereby prolonging the charge-discharge cycle life of the lithium-ion battery and improving its battery performance. In contrast to the electrolytic copper foils of Comparative Examples 1 to 7, because the temperature coefficient of resistance is not controlled in an appropriate range, the cycle life of the lithium-ion batteries of Comparative Examples 1-B to 7-B does not reach 800 times. The cycle life performance is significantly worse than that of the lithium ion batteries of Examples 1-B to 4-B.

According to the results in Table 3, because the electrolytic copper foils of Examples 5 to 7 control the temperature coefficient of resistance of the electrolytic copper foils in an appropriate range (that is, the α value is 0.0012 K ^-1 to 0.0039 K ^-1 ), therefore, the covering Copper laminates 5-A to 7-A performed well in the signal transmission loss analysis results. It can be proved that the electrolytic copper foil of the invention can indeed improve the thermal stability, thereby reducing the signal transmission loss of the copper-clad laminate including it, and improving the performance of the copper-clad laminate. In contrast to the electrolytic copper foils of Comparative Examples 8 and 9, since the temperature coefficient of resistance was not controlled within an appropriate range, the analysis results of the signal transmission loss of the copper-clad laminates including Comparative Examples 1-B to 7-B were significantly different. good.

Based on the results of the above Table 2 and Table 3, this creation can effectively suppress the increase in the internal resistance of the electrolytic copper foil caused by the temperature rise of the electrolytic copper foil due to product application by regulating the range of the temperature coefficient of resistance of the electrolytic copper foil phenomenon, thereby improving the thermal stability of electrolytic copper foil; in addition, this creation can also provide the effect of extending cycle life when it is subsequently applied to lithium-ion batteries, and provide effects such as reducing signal transmission loss when it is subsequently applied to printed circuit boards , thereby improving the quality of application products.

10: Electrodeposition device 11: Cathode roller 12: Anode plate 13: copper electrolyte 14: Feed pipe 20: guide roller 211: The first guide roller 212: Second guide roller 213: The third guide roller 214: The fourth guide roller 215: The fifth guide roller 216: The sixth guide roller 217: The seventh guide roller 22: Air Knife 23: Winding wheel 30: Surface treatment device 31: Anti-rust treatment tank 311a: the first plate 311b: the first plate 32: pickling tank 33: Coarsening treatment tank 331: second plate 34: Copper clad treatment tank 341: The third plate 35: Nickel plating tank 351: The fourth plate 36: Galvanizing tank 361a: fifth plate 361b: fifth plate 37: chrome tank 371a: the sixth plate 371b: the sixth plate 38: Silane coupling agent spraying device 39: Oven 40: Electrolytic copper foil 41: Raw foil 411: deposition surface 412: roller surface 42: Surface treatment layer 42a: first surface treatment layer 42a': the first processing surface 42b: Second surface treatment layer 42b': the second processing surface 421:Coarsening layer 422: copper clad layer 423: nickel layer 424a: the first zinc layer 424b: second zinc layer 425a: first chrome layer 425b: second chromium layer 426: Silane coupling treatment layer

FIG. 1 is a schematic diagram of the production process of the electrolytic copper foil of Example 1. FIG. 2 is a cross-sectional view of the electrodeposited copper foil of Example 1. FIG. 3 is a schematic diagram of the production process of the electrolytic copper foil of Example 5. FIG. 4A is a cross-sectional view of the electrodeposited copper foil of Example 5. FIG. FIG. 4B is a cross-sectional view of the electrodeposited copper foil of Example 7. FIG.

none

40: Electrolytic copper foil 41: Raw foil 411: deposition surface 412: roller surface 42: Surface treatment layer 42a: first surface treatment layer 42a': the first processing surface 42b: Second surface treatment layer 42b': the second processing surface

Claims (13)

An electrolytic copper foil, wherein the temperature coefficient of resistance (α value) of the electrolytic copper foil is 0.0012K ^-1 to 0.0039K ^-1 ; wherein the electrolytic copper foil includes an original foil and a first Surface treatment layer; the original foil has opposite deposition surface and roller surface, and the first surface treatment layer is arranged on the deposition surface or the roller surface of the original foil. The electrodeposited copper foil as described in Claim 1, wherein the temperature coefficient of resistance of the electrodeposited copper foil is measured from the electrodeposited copper foil that has been annealed for 6 hours, and the annealing process is carried out in an environment at a temperature of 110°C . The electrodeposited copper foil according to claim 1 or 2, wherein the first surface treatment layer has a first treatment surface opposite to the original foil; the average height (Rc) of the roughness curve elements of the first treatment surface is: 0.34 microns to 9.72 microns. The electrolytic copper foil according to claim 3, wherein the first surface treatment layer includes an anti-rust layer, and the Rc of the first treatment surface is 0.34 microns to 1.63 microns. The electrolytic copper foil according to claim 3, wherein the first surface treatment layer includes a roughened layer, and the Rc of the first treatment surface is 0.38 microns to 9.72 microns. The electrolytic copper foil as described in claim 5, wherein the first surface treatment layer further includes at least one sublayer selected from the group consisting of a copper clad layer, a nickel layer, a zinc layer, a chromium layer, and a silane coupling treatment layer. A layer is formed on the roughened layer. The electrolytic copper foil as described in claim 1, wherein the electrolytic copper foil further includes a second surface treatment layer disposed on the original foil; the original foil is located between the first surface treatment layer and the second surface treatment layer Between, the second surface treatment layer has a second treatment surface opposite to the original foil. The electrolytic copper foil according to claim 7, wherein the second surface treatment layer includes an anti-rust layer, and the Rc of the second treatment surface is 0.34 microns to 1.63 microns. The electrolytic copper foil according to claim 7, wherein the second surface treatment layer includes a roughened layer, and the Rc of the second treatment surface is 0.38 microns to 9.72 microns. The electrolytic copper foil as claimed in claim 9, wherein the second surface treatment layer further includes at least one sub-layer selected from the group consisting of a copper clad layer, a nickel layer, a zinc layer, a chromium layer, and a silane coupling treatment layer. A layer is formed on the roughened layer. The electrolytic copper foil according to claim 7, wherein the second surface treatment layer includes at least one sublayer selected from the group consisting of a copper clad layer, a nickel layer, a zinc layer, a chromium layer, and a silane coupling treatment layer . An electrode for a lithium ion battery, comprising the electrolytic copper foil according to any one of claims 1 to 11, at least one adhesive and at least one active material. A copper-clad laminate, comprising the electrolytic copper foil and a resin substrate as described in any one of Claims 1 to 11.

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