▎ 摘　　要

NOVELTY - Use of electrochemical capacitor consisting of electrochemically exfoliated graphene, for AC line filter, is claimed. USE - Use of electrochemical capacitor for AC line filter (claimed), and as decoupling capacitors in power supply circuits. ADVANTAGE - The use of electrochemical capacitor is economical, and provides larger capacitance per volume than other types of electrostatic capacitors. The electrochemically exfoliated graphene is prepared by an economically efficient and easy-to-perform process, which enables preparation of electrochemical capacitors having low RC time constant. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) manufacture of AC line filter, which involves preparing graphene by electrochemical exfoliation, manufacturing an electrochemical capacitor having at least one electrode made of electrochemically exfoliated graphene, and manufacturing an AC line filter containing electrochemical capacitor; and (2) electrochemical capacitor, which has resistor-capacitor (RC) time constant of less than 1.0 millisecond at 120 Hz.