Kate

Less-defective graphene oxide sheets with a small average size of 0.7 µm are electrochemically reduced to form a hydrogel film with highly oriented porous structure. It is applied as the electrode of organic electrochemical capacitor (OEC) after solvent change with organic electrolyte and deep reduction in this organic medium. At 120 Hz, the typical OEC exhibits a high areal specific energy density of 472 µF V² cm⁻² with a wide workable voltage window of 2.5 V, a phase angle of −80.5°, a resistor-capacitor time constant (τ_RC) of 0.219 ms, and an excellent electrochemical stability. Thus, it is promising to replace aluminum electrolytic capacitors for AC line filtering. Furthermore, two identical OECs connected in series keep the performance of single device, making them practically applicable in electronics.

An organic electrochemical capacitor (OEC) based on electrochemically reduced less defective graphene oxide exhibits excellent AC line-filtering performance. At 120 Hz, it displays a high areal specific energy density, ultrafast rate capability, and excellent electrochemical stability. These OECs can be connected in series or parallel for practical applications.