A method for manufacturing a copper foil with a rough surface in a plating tank includes causing an electrolyte solution to flow between an anode and a cathode with a current density of 5 ASF-40 ASF. The copper foil with a rough surface including dense nodules of single copper crystals is deposited on the cathode. The electrolyte solution includes chloride ions (20 ppm-80 ppm), polyethylene glycol (PEG) with a molecular weight of 400-8000 (100 ppm-700 ppm), sulfuric acid (20 g/L-200 g/L), copper sulfate pentahydrate (70 g/L-320 g/L) and a sulfur compound (1 ppm-60 ppm).

An electrolyzed copper foil and a current collector of an energy storage device are provided. The electrolyzed copper foil includes a transition layer and a nano-twin copper layer formed on the transition layer. The transition layer has an equiaxial grain of a (111) plane having a volume ratio of 20-40%, a (200) plane having a volume ratio of 20-40%, and a (220) plane having a volume ratio of 20-40%. A thickness of the transition layer is 0.2 μm to 1.5 μm. The nano-twin copper layer has a columnar grain of the (111) plane having a volume ratio of more than 85%, and a thickness of the nano-twin copper layer is 3 μm to 30 μm.

Surface-treated copper foils including a copper foil having a first side and an opposite-facing second side and two treatment layers disposed on the first side and the second side respectively are described. Each treatment layer provides a treated surface which exhibit a ten-point average roughness Rz in a range of 1.2 m to 4.6 m and a peak density (Spd) in a range of 490,000 to 1,080,000 mm.sup.2. Additionally, the Cr content in each of the treatment layers is a range of 25 to 70 g/dm.sup.2. The surface-treated copper foils have excellent electrode active material coating properties, such as good adhesion and uniformity.

Provided are an electrolytic copper foil, and an electrode and a copper-clad laminate comprising the same. The electrolytic copper foil comprises a base copper layer having a drum side and a deposited side; wherein the electrolytic copper foil has a Charpy impact strength from 0.4 J/mm.sup.2 to 5.8 J/mm.sup.2.

The present invention relates to an electrolytic copper foil for a secondary battery and a method of producing the same. The electrolytic copper foil for a secondary battery, in which a burr and curl of a negative electrode plate are inhibited from being formed after an electrolytic copper foil is coated with a negative electrode active material, thereby increasing the loading volume of a negative electrode and increasing a capacity. The electrolytic copper foil for a secondary battery is produced from a plating solution containing Total Organic Carbon (TOC) by using a drum, in which the electrolytic copper foil is formed of one surface that is in direct contact with the drum and the other surface that is an opposite surface of the one surface, and an average cross-sectional grain size of the one surface is 80% or less of an average cross-sectional grain size of the other surface.

The present invention provides a surface treated copper foil in which a dropping of the roughening particles from a roughening treatment layer on the surface of the copper foil is suppressed and an occurrence of wrinkles or stripes when bonding with an insulating substrate is suppressed. The surface of the roughening treatment layer satisfies one or more of the following: a roughness Ra is 0.08 to 0.20 m, a roughness Rz is 1.00 to 2.00 m, a roughness Sq is 0.16 to 0.30 m, a roughness Ssk is 0.6 to 0.35, a roughness Sa is 0.12 to 0.23 m, a roughness Sz is 2.20 to 3.50 m, a roughness Sku is 3.75 to 4.50, and a roughness Spk is 0.13 to 0.27 m, a glossiness of a TD of the surface of the side of the roughening treatment layer of the surface treated copper foil is 70% or less.

The present invention provides a surface treated copper foil in which a dropping of the roughening particles from a roughening treatment layer provided on the surface of the copper foil is favorably suppressed and an occurrence of wrinkles or stripes when bonding with an insulating substrate is favorably suppressed. The surface treated copper foil comprises a copper foil, and a roughening treatment layer on at least one surface of the copper foil, wherein an aspect ratio of roughening particles of the roughening treatment layer satisfies one or more of the following items (1) and (2), the aspect ratio being a height of the roughening particles/a thickness of the roughening particles: (1) the aspect ratio of the roughening particles is 3 or less, (2) the aspect ratio of the roughening particles satisfies any one of the following items (2-1) or (2-2): (2-1) the aspect ratio of the roughening particles is 10 or less in the case that the height of the roughening particles is more than 500 nm and 1000 nm or less, (2-2) the aspect ratio of the roughening particles is 15 or less in the case that the height of the roughening particles is 500 nm or less; and a glossiness of a TD of the surface of the side of the roughening treatment layer of the surface treated copper foil is 70% or less.

Electrodeposited copper foils possessing properties for manufacturing lithium ion rechargeable secondary batteries are described, including methods of making the electrodeposited copper foils, methods for making the battery, and the resultant battery. The electrodeposited copper foils have a specific burst strength in the range of 1.5 to 4.3 kPa*m.sup.2/g and a tensile strength in the range of 30 to 40 kgf/mm.sup.2. The deposited side of the electrodeposited copper foil has a surface hardness in the range of 0.2 to about 2.0 Gpa by nano indentation analysis to resist wrinkling during pressing of the active materials on the electrodeposited copper foil. The foil exhibits reduced copper burr formation and burr size after clipping.

A micro-roughened electrodeposited copper foil and a copper foil substrate are provided. The micro-roughened electrodeposited copper foil includes a micro-rough surface. The micro-rough surface has a plurality of peaks, a plurality of V-shaped grooves and a plurality of micro-crystal clusters. Each of the V-shaped grooves is defined by adjacent two of the peaks and has an average depth less than 1 m. The micro-crystal clusters are correspondingly located on the tops of the peaks and each thereof has an average height less than 1.5 m. The micro-rough surface of the micro-roughened electrodeposited copper foil has an Rlr value less than 1.06.

The present invention relates to: an electrolytic copper foil having high dimensional stability and texture stability in a high temperature environment of a process for manufacturing an Li secondary battery; and a manufacturing method therefor. The electrolytic copper foil of the present invention has a thermal expansion coefficient of 17.1-22 m/(m.Math. C.) in a temperature region of 30-190 C., has a variation of full width at half maximum of the (220) plane of 0.81-1.19 according to heat treatment for 30 minutes at 190 C., and has a weight deviation of 5% or less in the transverse direction.