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

Zn‐ion hybrid micro‐supercapacitors with ultrahigh areal energy density (115.4 μWh cm⁻² at 0.16 mW cm⁻²) and long‐term durability are successfully fabricated by employing a capacitor‐type activated‐carbon cathode and a battery‐type electrodeposited Zn‐nanosheet anode in a ZnSO₄‐based aqueous electrolyte. The fabricated high‐performance hybrid microsupercapacitors offer great opportunities for new‐generation miniaturized energy‐storage devices.

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.

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