ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

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

E-mail: josiel.martins.costa@gmail.com

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.

DOI: 10.1007/s11696-018-0661-x

Chemical Papers 73 (5) 1103–1112 (2019)