ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Influence of current density and W concentration on Co–W alloys used as catalysts in electrodes for Li–O2 batteries
Josiel Martins Costa, Thayane Carpanedo de Morais Nepel, and Ambrósio Florêncio de Almeida Neto
University of Campinas, Campinas, Brazil
Abstract: In this study, we verified the influence of tungsten (W) concentrations and current density for the electroplating of the cobalt–tungsten (Co–W) alloy on two substrates (nickel foam and steel mesh). The statistical evaluation showed a mathematical model that related the efficiency of deposition with the parameters analyzed. The efficiency varied from 0 to 60.05% for the nickel foam and 0 to 64.39% for the steel mesh. Scanning electron microscopy showed that to increase the current density made the surface less uniform, due to the size of the grains formed and X-ray diffraction pointed to the formation of amorphous coating alloys. Electrodeposition of the alloy in the steel mesh occurred with greater contribution by forced convection, as opposed to the nickel foam that had a smaller contribution, according to the effects of fluid dynamics. The Co–W alloys evidenced by energy-dispersive X-rays spectroscopy were tested in the cell with a constant pressure of O2 and presented an alternative for the use of catalysts in Li–O2 batteries.
Keywords: Coating materials ; Co–W alloy ; Electroplating ; Nickel foam ; Steel mesh
Full paper is available at www.springerlink.com.
Chemical Papers 73 (5) 1103–1112 (2019)