Macroporous defective tungsten oxide nanostructure electrodes deliver ultrahigh capacitance and remarkable long cyclic durability in LiCl electrolyte

Abstract

Tungsten oxide (WO3) has been considered as an fascinating candidate for supercapacitors (SCs) material because of its desirable physico-chemical properties and electrochemical behaviors. Nevertheless, it is still a significant challenge to enhance its electrochemical properties and stability. Herein, we report an electroreduction strategy to fabricate the macroporous defective tungsten oxide nanostructure (ER-WO3) as a negative electrode material with outstanding electrochemical behavior and remarkable cycling durability in 5 M LiCl aqueous electrolyte, which attributes to the introduction of oxygen deficiencies. The ER-WO3 electrode exhibits a large areal capacitance of 244.7 mF cm−2 and an ultrahigh gravimetric specific capacitance of 266.6 F g−1 at scan rate of 50 mV s−1. More importantly, the ER-WO3 product also delivers an ultralong cyclic stability with 97.4% capacitance retention after 5000 cycles. Such these optimized properties of the ER-WO3 nanostructure electrode will promote its applications in the field of science and technology.