Zn‐Ion Hybrid Micro‐Supercapacitors with Ultrahigh Areal Energy Density and Long‐Term Durability

Abstract

Abstract On‐chip micro‐supercapacitors (MSCs), as promising power candidates for microdevices, typically exhibit high power density, large charge/discharge rates, and long cycling lifetimes. However, as for most reported MSCs, the unsatisfactory areal energy density (<10 µWh cm −2 ) still hinders their practical applications. Herein, a new‐type Zn‐ion hybrid MSC with ultrahigh areal energy density and long‐term durability is demonstrated. Benefiting from fast ion adsorption/desorption on the capacitor‐type activated‐carbon cathode and reversible Zn stripping/plating on the battery‐type electrodeposited Zn‐nanosheet anode, the fabricated Zn‐ion hybrid MSCs exhibit remarkable areal capacitance of 1297 mF cm −2 at 0.16 mA cm −2 (259.4 F g −1 at a current density of 0.05 A g −1 ), landmark areal energy density (115.4 µWh cm −2 at 0.16 mW cm −2 ), and a superb cycling stability without noticeable decay after 10 000 cycles. This work will inspire the fabrication and development of new high‐performance microenergy devices based on novel device design.