Tungsten oxide and carbide composite synthesized by hot filament chemical deposition as electrodes in aqueous-based electrochemical capacitors

Author(s)

Soares, Davi M. ^[1] ; Vicentini, Rafael ^[1] ; Peterlevitz, Alfredo C. ^[1] ; Rodella, Cristiane B. ^[2] ; da Silva, Leonardo M. ^{[3, 4]} ; Zanin, Hudson ^[1]

Affiliation

^[1] Univ Estadual Campinas, Ctr Innovat New Energies, Sch Elect & Comp Engn, Adv Energy Storage Div, Carbon Sci Tech Labs, Av Albert Einstein 400, BR-13083852 Campinas, SP - Brazil

^[2] Brazilian Ctr Energy & Mat CNPEM, Brazilian Synchrotron Light Lab LNLS, CP 6192, BR-13083970 Campinas, SP - Brazil

^[3] Fed Univ Jequitinhonha & Mucuris Valley, Inst Sci & Technol, Highway MGT 367, Km 583, 5000, BR-39100000 Diamantina, MG - Brazil

^[4] Fed Univ Jequitinhonha & Mucuris Valley, Fac Chem Engn, Highway MGT 367, Km 583, 5000, BR-39100000 Diamantina, MG - Brazil

• Document type: Journal article
• Source: JOURNAL OF ENERGY STORAGE; v. 26, DEC 2019.
• Web of Science Citations: 4

Abstract

Developing more sustainable, low cost and feasible energy storage devices is a keystone of aerospace, automobile, and electronics industries. In research new materials and techniques that allow their production in large scale are studied by researchers around the world. Regarding materials, supercapacitors, for instance, may have carbon based materials on electrodes, owing to their chemical stability, low cost, and safety; however, their specific capacitance is lower when compared to other materials. Additionally, materials that may provide higher capacitance-due to faradaic or redox reactions - are also studied. Within this group, transition metal oxides are potential candidates for that, once faradaic behavior may provide higher capacitance values; however, not cyclability in most cases. Thus, this work presents a composite material with tungsten carbide (W2C) and tungsten oxide species (WxOy), which showed both faradaic behavior and cyclability. This composite material was synthesized by deposition of tungsten using a technique known as hot filament chemical vapor deposition (HFCVD). In this process, sublimation of tungsten occurred under H-2 constant flow; thus, reducing the metallic tungsten; while oxide species were formed by spontaneous passivation. Experimental results indicate that the efficiency improved from 59% to 85% for first and 10, 000th cycles, respectively, with boost of specific capacitance of 160%. In sum, the material reported herein presents the unique aspect of improving its properties during cyclability. Therefore, such feature and synthesis process may enable its use as renewable energy storage devices. (AU)

• FAPESP's process: 17/11958-1 - CINE - Advanced Energy Storage Division
• Grantee: Rubens Maciel Filho
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 17/19222-4 - Development of storage and supplier device of electric power and methodology of dynamic analysis in operation mode
• Grantee: Lenon Henrique da Costa
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 16/25082-8 - Development of prototype of energy storer and supplier
• Grantee: Lenon Henrique da Costa
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/02163-7 - Development of supercapacitors devices from graphene, carbon nanotubes and diamonds
• Grantee: Hudson Giovani Zanin
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 17/03640-1 - Development of prototype of powerful energy storer and supplier
• Grantee: Otavio Cristiano Vilas Boas
• Support Opportunities: Scholarships in Brazil - Master