Electrical Conduction in CoWO4 Flanked by Carbon and ZnFe2O4 Nanoparticulate Assembly and a Poly(ethylene oxide) Gel for Enhanced Electrochemical Activity

Deshagani, Sathish and Naskar, Ishita and Padval, Gaurav Ganesh and Ghosal, Partha and Deepa, Melepurath (2022) Electrical Conduction in CoWO4 Flanked by Carbon and ZnFe2O4 Nanoparticulate Assembly and a Poly(ethylene oxide) Gel for Enhanced Electrochemical Activity. ACS Applied Energy Materials. pp. 1-15. ISSN 2574-0962

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Abstract

Semiconducting cobalt tungstate flanked by carbon (CoWO4@C) polyhedral microstructures with smooth facets and zinc ferrite (ZnFe2O4) polydisperse interconnected nanoparticles via intrinsic mechanisms of hole polaron transfer from Co3+ to Co2+ sites and electron hopping between Fe2+ and Fe3+ states, respectively, were endowed with high room-temperature electrical conductivities (>0.9 mS cm(-1)), thus enabling the fabrication of a high-performance asymmetric supercapacitor (ASC) possessing an outstanding rate capability as well as a good trade-off between power (P) and energy (E) densities. Furthermore, electrochemical response comparison of CoWO4@C//ZnFe2O4 ASCs encompassing three different electrolytes (aqueous KOH, KOH-PEO gel, and KOH-PVA gel) revealed that the KOH-PEO gel cell outperformed the other two ASCs, with a specific capacity (SC) of 339 F g(-1) (at 1 A g(-1)) and E-max and P-max of 105 Wh kg(-1) and 3.2 kW kg(-1) achieved over an operational voltage window of 1.5 V while retaining 97% of the original SC after 10,000 cycles. With KOH and KOH-PVA gel, while the P-max remained the same, SCs of 300 and 322 F g(-1) and E-max's of 93 and 100 Wh kg(-1) were obtained. The high ionic conductivity (81.6 mS cm(-1)) of the KOH-PEO gel is attributed to the hydrogen bonded networked structure of the gel with free spaces that allows ions to move freely within the polymer matrix. Further, the oxygens along the polymer chains ensure a high dissociation of KOH. The gel also serves as an ion-reservoir and these factors cumulatively resulted in the enhanced performance of the ASC. This study showcases that scalable, low-cost, leak-proof supercapacitors can be fabricated using environmentally friendly electroactive materials that can be synthesized easily using simple wet chemistry techniques.

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IITH Creators:

IITH Creators	ORCiD
Deepa, Melepurath	https://orcid.org/0000-0001-7070-5100

Item Type:

Article

Additional Information:

Financial support from the Department of Science & Technology of India (Project: India-UK Center for Education and Research in Clean Energy (IUCERCE) , Grant DST/RCUK/JVCCE/2015/04 (1) (G) ) is gratefully acknowledged by M. Deepa, I. Naskar, and S. Deshagani. I.N. is thankful to the Council of Scientific and Industrial Research for a junior research fellowship.

Uncontrolled Keywords:

supercapacitor ,gel liquid ,conduction, cobalt tungstate, zinc ferrite

Subjects:

Chemistry

Divisions:

Department of Chemistry

Depositing User:

. LibTrainee 2021

Date Deposited:

21 Nov 2022 09:44

Last Modified:

21 Nov 2022 09:47