Abstract: [Summary] Provided is a cathode active material for a lithium secondary battery having a layered rock salt structure, including a secondary grain formed of a large number of primary grains each having an average grain size of 0.01 ?m or more and 5 ?m or less, in which the secondary grain has the following characteristics: a (003) plane orientation degree of 60% or more; an average grain size of 1 ?m or more and 100 ?m or less; an aspect ratio of 1.0 or more and less than 2; a voidage of 3% or more and 30% or less; an average pore size of 0.1 ?m or more and 5 ?m or less; and a value obtained by dividing the average grain size of each of the primary grains by the average pore size of 0.1 or more and 5 or less.

Abstract: DLC film formed on at least one surface of a plastic film, and this DLC film has a composition comprising 75 to 55 mol% of carbon and 25 to 45 mol% of hydrogen. And this DLC film is formed by a plasma deposition process while the plastic film is loaded with a tensile force in a biaxial direction.