Current collector, electrode, secondary battery and capacitor

Abstract

Provided are a current collector which has an excellent high-rate property and exerts a sufficient safety function when employed in a secondary battery or a capacitor, as well as an electrode, a secondary battery or a capacitor in which said current collector is employed. According to the invention, a current collector is provided which comprises: metal foil; and a conductive layer with a film thickness of 0.1 μm to 10 μm formed on a surface of said metal foil. Here, said conductive layer includes a conductive material and a binder material. A melting point of said binder material is 80° C. to 150° C. Further, said binder material shows, in differential scanning calorimetry (DSC) in a range from room temperature to 200° C., one or more endothermic peaks in the heating-up process. In a case where said binder material shows two or more endothermic peaks, each difference between said peaks is 15° C. or more. Moreover, said binder material shows one or more exothermic peaks in the cooling-down process. In a case where said binder material shows only one exothermic peak, said exothermic peak falls within a range of 50 to 120° C., and a width at half maximum of said exothermic peak is 10° C. or less. On the other hand, in a case where said binder material shows two or more exothermic peaks, a maximum exothermic peak among said exothermic peaks falls within a range of 50 to 120° C., and a width at half maximum of said exothermic peak is 10° C. or less.