Vanadium oxide - poly(3,4-ethylenedioxythiophene) cathodes for zinc-ion batteries: effect of synthesis temperature

Abstract

Vanadium oxide composites with conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) were obtained by one-step microwave-assisted hydrothermal synthesis at two different temperatures: 120 and 170 °C (denoted as V-120 and V-170, respectively). The structure and composition of the obtained samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, X-ray photoelectron spectro­scopy (XPS), and thermogravimetric (TG) analysis. The detailed study of the electro­chemical properties of the composites as cathodes of aqueous zinc-ion battery was per­formed by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) at different current densities and by electrochemical impedance spectroscopy (EIS). It was shown that V-120 demonstrated excellent electrochemical performance in the 0.3 to 1.4 V vs. Zn/Zn2+ potential range reaching specific capacities of up to 390 mA∙h∙g−1 at 0.3 A∙g−1 with excel­lent capacity stability after 1000 charge-discharge cycles. Its functional parameters were found to be much better than those of the electrodes based on the V-170 composite obtained at a higher temperature. The effect of the synthesis temperature on the electro­chemical properties is discussed in terms of the crystallographic, compositional, and thermogravimetric properties of the samples.

Rational Design of Ni-Doped V2O5@3D Ni Core/Shell Composites for High-Voltage and High-Rate Aqueous Zinc-Ion Batteries

“…In a long-cycle stability test, even under a high current density of 4.8 A g −1 , the Ni-V2O5@3D Ni@CC-based ZIB still maintains a nearly non-decreased 100% CE after cycling over 500 times with a specific capacity of about 110 mAh g −1 (a volume specific capacity of about 430 mAh cm −3 , shown in Figure 4f). The performance reported here is better than that of other V2O5-based compounds such as V2O5/CC, V2O5/MXene, NH4 + -V2O5 and V2O5/rGO [46][47][48][49][50]. Meanwhile, the smaller resistance of the Ni-V2O5@3D Ni@CC-based ZIB in comparison with the V2O5@CC-based ZIB, proved by an electrochemical impedance spectroscopy (EIS) test (which can be seen in Figure S7), demonstrates well that the incorporation of Ni into the V2O5 active material not only benefits the ZIB's energy storage performance and cycle stability but also improves the Zn 2+ transport ability inside the cathode, giving the Ni-V2O5@3D Ni@CC-based ZIB better application potential.…”

High-Performance Supercapacitors Utilising PEDOT Composite Electrodes; Synthesis, Characterisation and Electrochemical Performance Analysis

“…Poly (3,4-ethylenedioxythiophene) (PEDOT) is a conductive polymer known for its low cost, flexibility and good electrical conductivity, which results in fast electrochemical redox reactions [24]. For such reasons, PEDOT has been considered a potential candidate for use in electrochemical energy sources with good performance in terms of power and energy density [25][26][27][28][29]. The synthesis of PEDOT can be achieved using either chemical or electrochemical methods.…”