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

Zhang, Panpan; Li, Yang; Wang, Gang; Wang, Faxing; Yang, Sheng; Zhu, Feng; Zhuang, Xiaodong; Schmidt, Oliver G et al. · Adv Mater · 2019

basic_science · Level V

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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<sup>-2</sup> ) 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<sup>-2</sup> at 0.16 mA cm<sup>-2</sup> (259.4 F g<sup>-1</sup> at a current density of 0.05 A g<sup>-1</sup> ), landmark areal energy density (115.4 µWh cm<sup>-2</sup> at 0.16 mW cm<sup>-2</sup> ), 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.