A new potassium dual-ion hybrid supercapacitor based on battery-type Ni(OH)2 nanotube arrays and pseudocapacitor-type V2O5-anchored carbon nanotubes electrodes

摘要

Hybrid supercapacitors (HSCs) with the characteristics of high energy density, long cycle life and without altering their power density need to be developed urgently. Herein, a novel dual-ion hybrid supercapacitors (DHSCs) with Ni(OH)(2) nanotube arrays (NTAs) as positive electrode and V2O5 directly grown on freestanding carbon nanotubes (CNTs) as negative electrode is assembled. In charging mechanism of DHSCs, K+ are inserted into the V2O5 negative while OH- react with Ni(OH)(2) positive; during discharge, the K+ and OH- are released from V2O5 negative and Ni(OH)(2) positive, respectively, and return back to the electrolyte, which is quite different from traditional metal ion or alkaline supercapacitors. Because of the merits combining dual-ion mechanism and HSCs, the DHSC displays excellent capacity retention of similar to 81.4% after 10,000 cycles, high energy density of -25.4 mu Wh cm(-2) and high power density of similar to 4.66 mW cm(-2), indicating the potential applications in the further on flexible wearable electronics.

关键词