Results for “CoWO4” | Engineering Papers

DOE OSTI2020

Materials Data on CoWO4 by Materials Project

CoWO4 is zeta iron carbide-derived structured and crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. W6+ is bonded to six O2- atoms to form distorted WO6 octahedra that share corners with eight equivalent CoO6 octahedra and edges with two equivalent WO6 octahedra. The corner-sharing octahedra tilt angles range from 46–55°. There are a spread of W–O bond distances ranging from 1.84–2.12 Å. Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with eight equivalent WO6 octahedra and edges with two equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 46–55°. There are a spread of Co–O bond distances ranging from 2.10–2.13 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent W6+ and one Co2+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one W6+ and two equivalent Co2+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2022

Robust hierarchical three dimensional nickel cobalt tungstate-MXene nanocomposite for high performance symmetric coin cell supercapacitors

Design of rational electrode materials with hierarchically structured pseudocapacitive materials has been identified as a successful strategy for revamping the electrochemical characteristics of supercapacitors. However, the simultaneous assurance of strong electrical conductivity and higher specific capacitance via a simple and cost-effective synthesis protocol is of concern today. In this work, Ni-CoWO 4 incorporated MXene nanocomposite has been successfully prepared by a facile hydrothermal process. The structure, morphology, stoichiometry, and chemical characterization of the prepared Ni-CoWO 4 , Ti 3 C 2 T x , and Ni-CoWO4@MXene nanocomposite were explored extensively. MXene demonstrated a layered 2D nanoscale structure whereas pure Ni-CoWO 4 was composed of spherical nanoparticles. The composite Ni-CoWO 4 @MXene revealed the morphology of spherical Ni-CoWO 4 nanoparticles decorated on MXene sheets. Furthermore, a series of electrochemical characterizations illustrated the contribution of the delightful morphology of Ni-CoWO 4 @MXene composite to excellent electrochemistry. The resultant Ni-CoWO 4 @MXene electrode exhibited high specific capacitance of 582 Fg -1 at 1 A g -1 and 93.5 % capacitance retention over the 10,000 cycles., which is higher than that of the individual counterparts Ni-CoWO 4 and MXene. The excellent electrochemical performance of Ni-CoWO 4 @MXene is attributed to the synergistic interaction between Ni-CoWO4 nanoparticles and nanolayered MXene that may create new active sites that enhanced the charge transfer, charge/discharge kinetics and the electrical conductivity. Significantly, the unique Ni-CoWO 4 @MXene supercapacitor prototype delivered a higher energy density of 85.7 Wh kg -1 and power density of 0.85 kW kg -1 establishing its superiority over other Cosingle bondW based supercapacitors. A theoretical study was also performed to correlate the improved charge storage capacity of the prepared Ni-CoWO 4 @MXene composite.

25 ENERGY STORAGE↗