A Ni-plated steel sheet includes a base steel sheet and a Ni-based coating layer that is disposed on a surface of the base steel sheet. The distribution of carbon concentration in a depth direction obtained by performing GDS analysis on the Ni-plated steel sheet has a peak indicating the carbon concentration that is equal to or more than twice the carbon concentration of a thickness middle portion of the base steel sheet in the vicinity of an interface between the base steel sheet and the Ni-based coating layer.

Disclosed herein are a surface-treated copper foil for a negative electrode current collector for secondary batteries, a method for producing the same, and a negative electrode for secondary batteries including the same. The surface-treated copper foil includes needle-shaped copper particles formed on at least one surface thereof, wherein the copper particles have an average major-axis length of about 0.6 μm to about 2.0 μm and are separated from one another by a distance of about 1 μm to about 5 μm.

A steel sheet includes: a predetermined chemical composition; and a steel structure represented by, in area %, first martensite in which two or more iron carbides each having a circle-equivalent diameter of 2 nm to 500 nm are contained in each lath: 20% to 95%, ferrite: 15% or less, retained austenite: 15% or less, and the balance: bainite, or second martensite in which less than two iron carbides each having a circle-equivalent diameter of 2 nm to 500 nm are contained in each lath, or the both of these, in which the total area fraction of ND//<111> orientation grains and ND//<100> orientation grains is 40% or less, and the content of solid-solution C is 0.44 ppm or more.

A surface-treated copper foil includes a treating surface, and a peak extreme height (Sxp) of the treating surface being in a range of 0.4-2.5 μm, where the hysteresis loop of the surface-treated copper foil includes a first magnetization and a second magnetization when the magnetic field strength of the hysteresis loop is zero, and the absolute difference between the value of the first magnetization and the value of the second magnetization is in a range of 20-1200 emu/m.sup.3.

A method for compact and flat bismuth metal preparation by electrolysis is provided. In the method, one or more of β-naphthol, acacia, sulfonated and vulcanized alkylphenol ethoxylate and naphthol ethoxylate oxides are added to the acidic solution of bismuth methanesulfonate as additives, and the cathodic bismuth is obtained by electrolysis at 20-80° C. The method for bismuth metal preparation is simple and easy to promote, environment-friendly, and the obtained bismuth metal has a flat and compact surface and good plate formation effect.

The present invention relates to an electrolytic copper foil having excellent handling characteristics in the manufacture of copper foil and in post-processing for manufacturing a secondary battery. The present invention provides an electrolytic copper foil having a first surface and a second surface, wherein the texture coefficient of the (220) plane of the electrolytic copper foil is 0.4-1.32, the difference (|Δ(Rz/Ra)|) between Rz/Ra on the first surface and Rz/Ra on the second surface, of the electrolytic copper foil, is less than 2.42, and the difference (|ΔPD|) in peak density (PD) between the first surface and the second surface, of the electrolytic copper foil, is 96 ea or less.

A roughened nickel-plated sheet including a roughened nickel layer on at least one surface of a metal substrate as the outermost layer thereof, the roughened nickel layer being formed of a plurality of nickel protrusions. When the structure of the roughened nickel-plated sheet is observed at height positions with a focused ion beam scanning electron microscope (FIB-SEM), the absolute value of the change rate of the nickel occupancy is equal to or less than a predetermined value, and the nickel occupancy and the number of nickel protrusions present at a height position located 2.0 μm from the base position of the roughened nickel layer toward the surface in the height direction are equal to or more than predetermined values, respectively.

Provided is a steel sheet having excellent image clarity after painting, including: carbon (C): 0.001% to 0.03%, silicon (Si): 0.001% to 0.35%, manganese (Mn): 0.05% to 2.2%, phosphorus (P): 0.003% to 0.1%, sulfur (S): 0.001% or 0.025%, aluminum (Al): 0.01% to 0.1%, nitrogen (N): 0.001% to 0.007%, and a remainder of iron (Fe) and inevitable impurities. The microstructure of the steel sheet mainly is ferrite phases. An R-cube texture of a surface layer of the steel sheet is 5% or less by area %.

An electrolytic copper foil includes a raw foil layer having a first surface and a second surface opposite to the first surface. In the X-ray diffraction spectrum of the first surface, a ratio of the diffraction peak intensity I(200) of the (200) crystal face of the first surface relative to the diffraction peak intensity I(111) of the (111) crystal face of the first surface is between 0.5 and 2.0. In the X-ray diffraction spectrum of the second surface, a ratio of the diffraction peak intensity I(200) of the (200) crystal face of the second surface relative to the diffraction peak intensity I(111) of the (111) crystal face of the second surface is also between 0.5 and 2.0. A method for producing the electrolytic copper foil, and a lithium ion secondary battery is also provided.

A method for electro-depositing a radioactive material onto a metal substrate is disclosed. This is particularly well-suited for true random number generators. The method includes (a) at least partially masking the metal substrate to expose a metallic surface on the metal substrate; (b) connecting the metal substrate to a cathode of a current source; (c) submersing the exposed metallic surface into a solution containing radioactive metal ions, wherein the solution is connected to an anode of the current source; (d) removing the exposed metallic surface from the solution; (e) removing the solution from the exposed metallic surface; (f) measuring the amount of radioactivity emitted from the exposed metallic surface; and (g) repeating steps (c) through (f) until the amount of radioactivity measured in step (f) is stabilized relative to a previous measurement.