Defects engineering of Fe_2O_3@Sn_2O_3 nanosheet arrays for high-performance hybrid supercapacitor

摘要

Developing new-type electrode materials with high surface area, stable microstructure and high performance is important to global sustainability. Herein, we successfully fabricate an oxygen-deficient Fe2O3@Sn2O3 nano composite composed of Fe2O3 and Sn2O3 nanosheet-arrays on Ni foam. Benefiting from this kind of binder-free nanosheet-arrays microstructure and the oxygen vacancy, the electrode oxygen-deficient Fe2O3@Sn2O3 (V-O- Fe2O3@Sn2O3) nanocomposite possesses an excellent specific capacity (694.8 C g(-1)) at a current density of 1 mA cm(-2), superior rate capability (it still maintains 477.6 C g(-1) at 10 mA cm(-2)), and long cycle stability. The hybrid supercapacitor, assembled with V-O-Fe2O3@Sn2O3 nanosheet arrays as the cathode, active carbon (AC) as the anode and polyvinyl alcohol (PVA)/KOH as the gel electrolyte, delivers a high energy density of 39.1 W h kg(-1) at a power density of 1.28 kW kg(-1) and a retention rate of 81.4% even after 10,000 cycles at 1.6 A g(-1). Furthermore, two assembled devices in series can power a commercial LED for a long time.