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

Tungsten oxide (WO 3 ) 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-WO 3 ) 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-WO 3 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-WO 3 product also delivers an ultralong cyclic stability with 97.4% capacitance retention after 5000 cycles. Such these optimized properties of the ER-WO 3 nanostructure electrode will promote its applications in the field of science and technology.