Abstract: | Li‐ion capacitors (LICs) have demonstrated great potential for bridging the gap between lithium‐ion batteries and supercapacitors in electrochemical energy storage area. The main challenge for current LICs (contain a battery‐type anode as well as a capacitor‐type cathode) lies in circumventing the mismatched electrode kinetics and cycle degradation. Herein, a mesh‐like nitrogen (N)‐doped carbon nanosheets with multiscale pore structure is adopted as both cathode and anode for a dual‐carbon type of symmetric LICs to alleviate the above mentioned problems via a facile and green synthesis approach. With rational design, this dual‐carbon LICs exhibits a broad high working voltage window (0–4.5 V), an ultrahigh energy density of ( ), the highest power density of ( ) even under an ultrahigh energy density of ( ), as well as reasonably good cycling stability with capacity retention of 84.5% (only 0.0016% capacity loss per cycle) within 10 000 cycles under a high current density of 5 A g?1. This study provides an efficient method and option for the development of high performance LIC devices. |