High‐Performance Ytterbium‐Doped V₂O₅ ⋅ H₂O Binder‐Free Thin‐Film Electrodes for Supercapacitors

Abstract

In this work, honeycomb-like Yb-doped V 2 O 5 • nH 2 O binder-free thin film electrodes are synthesized via a simple and convenient sol-gel method. Benefiting from the synergy of V 2 O 5 • nH 2 O and rare-earth metal ion Yb 3 + , thin-layer honeycomb-like morphology formed upon the introduction of Yb 3 + into the V 2 O 5 • nH 2 O, which markedly promotes the electrochemical performance of the V 2 O 5 • H 2 O thin-film electrode. After the condition optimization, 8 % YbÀ V 2 O 5 • H 2 O exhibits superior electrochemical performance with a specific capacitance of 703 F g À 1 (at 1 A g À 1 )and outstanding cycling stability. Besides, owing to the ultrahigh conductivity of oxide super-P (OSP) nanoparticles, the V 2 O 5 • H 2 O@OSP-4 binder-free film electrode shows a high specific capacitance of 627 F g À 1 , which was prepared by the same simple sol-gel strategy. The assembled 8 % YbÀ V 2 O 5 • nH 2 O//V 2 O 5 • nH 2 O@OSP-4 device delivers a high specific energy density and excellent cycling stability. This study may have certain inspirations for the fabrication of thin-film electrodes for high-efficiency energy storage systems.