The present invention relates to an electrolytic copper foil for a secondary battery, having excellent flexural resistance, and a method for producing the electrolytic copper foil. The electrolytic copper foil for a secondary battery has excellent flexural resistance even without the use of many additives in a copper electrolyte when producing a copper foil. The electrolytic copper foil for a secondary battery according to the present invention is an electrolytic copper foil for a secondary battery, which is produced from a plating solution, containing total organic carbon (TOC), cobalt and arsenic, by using a drum and is coated with a negative electrode active material, wherein the ratio between the TOC, cobalt and arsenic contained in the electrolytic copper foil follows the following formula 1:
TOC/(cobalt+arsenic)=1.30-1.55.  [Formula 1]

The present invention relates to an electrolytic copper foil for a secondary battery, having excellent flexural resistance, and a method for producing the electrolytic copper foil. The electrolytic copper foil for a secondary battery has excellent flexural resistance even without the use of many additives in a copper electrolyte when producing a copper foil. The electrolytic copper foil for a secondary battery according to the present invention is an electrolytic copper foil for a secondary battery, which is produced from a plating solution, containing total organic carbon (TOC), cobalt and arsenic, by using a drum and is coated with a negative electrode active material, wherein the ratio between the TOC, cobalt and arsenic contained in the electrolytic copper foil follows the following formula 1:
TOC/(cobalt+arsenic)=1.30-1.55.  [Formula 1]

Provided is a metal matrix nanocomposite comprising: (a) a metal or metal alloy as a matrix material; and (b) multiple graphene sheets that are dispersed in said matrix material, wherein said multiple graphene sheets are substantially aligned to be parallel to one another and are in an amount from 0.1% to 95% by volume based on the total nanocomposite volume; wherein the multiple graphene sheets contain single-layer or few-layer graphene sheets selected from pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof and wherein the chemically functionalized graphene is not graphene oxide. The metal matrix exhibits a combination of exceptional tensile strength, modulus, thermal conductivity, and/or electrical conductivity.

A copper foil having high fracture energy to be strong against breakage is disclosed. An electrode for secondary batteries and a secondary battery exhibiting, by including the copper foil, excellent characteristics in terms of, for example, cycle lifespan, safety, and workability are also disclosed.

A copper foil having high fracture energy to be strong against breakage is disclosed. An electrode for secondary batteries and a secondary battery exhibiting, by including the copper foil, excellent characteristics in terms of, for example, cycle lifespan, safety, and workability are also disclosed.

A copper foil having high fracture energy after heat treatment to be strong against breakage is disclosed. Also disclosed are an electrode for secondary batteries and a secondary battery exhibiting, by including the copper foil, excellent characteristics in terms of, for example, cycle lifespan, safety, and workability.

A manufacturing method of copper foil and circuit board assembly for high frequency transmission are provided. Firstly, a raw copper foil having a predetermined surface is produced by an electrolyzing process. Subsequently, a roughened layer including a plurality of copper particles is formed on the predetermined surface by an arsenic-free electrolytic roughening treatment and an arsenic-free electrolytic surface protection treatment. Thereafter, a surface treatment layer is formed on the roughened layer, and the roughened layer is made of a material which includes at least one kind of non-copper metal elements and the concentration of the non-copper metal elements is smaller than 400 ppm. By controlling the concentration of the non-copper elements, the resistance of the copper foil can be reduced.

A manufacturing method of copper foil and circuit board assembly for high frequency transmission are provided. Firstly, a raw copper foil having a predetermined surface is produced by an electrolyzing process. Subsequently, a roughened layer including a plurality of copper particles is formed on the predetermined surface by an arsenic-free electrolytic roughening treatment and an arsenic-free electrolytic surface protection treatment. Thereafter, a surface treatment layer is formed on the roughened layer, and the roughened layer is made of a material which includes at least one kind of non-copper metal elements and the concentration of the non-copper metal elements is smaller than 400 ppm. By controlling the concentration of the non-copper elements, the resistance of the copper foil can be reduced.

Provided is an electrodeposited copper foil having high smoothness and at the same time exhibiting high flexibility (particularly, high flexibility after annealing at 180° C. for 1 hour) suitable for a flexible substrate. This electrodeposited copper foil has a ten-point average roughness Rz of 0.1 μm or larger and 2.0 μm or smaller on at least one surface, has a tensile strength measured in accordance with IPC-TM-650 of 56 kgf/mm.sup.2 or more and less than 65 kgf/mm.sup.2 in an unannealed original state, and has a tensile strength measured in accordance with IPC-TM-650 of 15 kgf/mm.sup.2 or more and less than 25 kgf/mm.sup.2 after annealing at 180° C. for 1 hour.

Provided is an electrodeposited copper foil having high smoothness and at the same time exhibiting high flexibility (particularly, high flexibility after annealing at 180° C. for 1 hour) suitable for a flexible substrate. This electrodeposited copper foil has a ten-point average roughness Rz of 0.1 μm or larger and 2.0 μm or smaller on at least one surface, has a tensile strength measured in accordance with IPC-TM-650 of 56 kgf/mm.sup.2 or more and less than 65 kgf/mm.sup.2 in an unannealed original state, and has a tensile strength measured in accordance with IPC-TM-650 of 15 kgf/mm.sup.2 or more and less than 25 kgf/mm.sup.2 after annealing at 180° C. for 1 hour.