▎ 摘　　要

Miniaturization of energy storage devices with enhanced performance metrics can reduce the footprint of microdevices being used in our daily life. Micro-supercapacitor architectures with planar geometry provides several advantages, such as, the ability to control and reduce the distances ions travel between two electrodes, easy integration to microdevices, and offer the potential of being extended into 3D without compromising the interelectrode distances. Here, focused ion beam (FIB) technology is used to directly write miniaturized planar electrode systems of reduced graphene oxide (FIB-rGO) on films of graphene oxide. Using optimized ion beam irradiation, interdigitated FIB-rGO electrode designs with 40 m long and 3.5 m wide fingers with ultrasmall interelectrode spacing of 1 m demonstrate a large capacitance (102 mF cm(-2)), ultrasmall time response (0.03 ms), low equivalent series resistance (0.35 m cm(2)), and retain 95% of the capacitance after 1000 cycles at an ultrahigh current density of 45 mA cm(-2). These performance metrics show remarkable improvements on several counts of supercapacitor performance over existing reports due to the miniaturized electrode dimensions and minimal damage to the graphene sheets. It is believed that these results can provide avenues for large-scale fabrication of arrayed, planar, high-performance micro-supercapacitors with a small environmental footprint.