▎ 摘　　要

The actual relevance of supercapacitors for powering daily-life electronic devices as well as in future outerspace applications demands for innovative, high-performance and low-cost electrode materials. In this regard, the present contribution reports the electrochemical performance of a new supercapacitor electrode based on a layer-by-layer assembled maghemite/magnetite/reduced graphene oxide (MAG-RGO) nanocomposite film. The MAG-RGO electrode displays specific capacitance as high as 691.29 F g(-1) at 5.6 A g(-1). Its enhanced charge-storage ability is accomplished by proper adjustment of the electrode porosity with the Fe2+ to RGO mass ratio and the number of deposited MAG-RGO bilayers, which work synergistically in a combination of EDLC and pseudocapacitive behaviors. Fitting of the electrochemical impedance of different electrodes with a transmission line based equivalent circuit shows that the appropriate porosity is attained at Fe2+/RGO 5:1 and between 7 and 10 bilayers, when the electrode's specific capacitance reaches its maximum and remains practically unaltered (87.5% of retention) over 10,000 charge-discharge cycles. Since the nanocomposite preparation and subsequent film assembly are relatively simple and inexpensive, while providing full control of its electrochemical behavior at the nanometer range, the MAG-RGO nanocomposite film electrode is a promising cog-effective alternative for future supercapacitor development and applications.