Abstract: Provided is an electrolytic solution exhibiting excellent withstand voltage and satisfactory characteristics even at low and high temperatures. The invention is an electrolytic solution that includes a cyclic carbonate (I-1) represented by formula (I-1): (in the formula, R is an alkyl group having two or more carbon atoms, a fluorine-containing alkyl group having two or more carbon atoms, an alkoxy group or a fluorine-containing alkoxy group, in which an oxygen atom may be inserted between carbon atoms); a cyclic carbonate (I-2) different from the cyclic carbonate (I-1); and an electrolyte salt (II)).

Abstract: The present invention aims to provide an electrochemical device excellent in high temperature storage characteristics and cycling characteristics at high voltages, and a nonaqueous electrolyte for the electrochemical device.

Abstract: The present invention provides a lithium ion secondary cell excellent in high-temperature storage characteristics and high voltage cycle characteristics; and a nonaqueous electrolyte for the cell.

Abstract: The present invention directs to a non-aqueous electrolyte solution, including (I) at least one compound selected from the group consisting of fluorinated linear sulfones and fluorinated linear sulfonic acid esters, and (II) an electrolyte salt. Such a non-aqueous electrolyte solution has high oxidation resistance, minimizes its decomposition even when hydrofluoric acid is produced. Also, the solution is less likely to cause, in the case of being used for a secondary cell, swelling of the cell and lowering of the battery performance.

Abstract: A method of preparing a hard disc comprising steps of:immersing an aluminum or aluminum alloy substrate in a zincate solution containing a zinc compound, an alkali hydroxide, and at least one amine to thereby form a zincate film on the surface of the substrate,immersing the zincate film-formed substrate in an electroless nickel plating solution comprising a water-soluble nickel salt, a complexing agent, and a hypophosphite to thereby form a nickel--phosphorus alloy layer on the surface of the zincate film-coated substrate, and forming a magnetic layer on the nickel--phosphorus alloy layer.