Ugradnja V2O5 u reducirani grafenov oksid i njegova primjena u vodenim Zn-ionskim baterijama

master's thesis

• Title (english): Graphene-encapsulated V2O5 for application in aqueous Zn-ion battery
• Author: Anđela Mišković
• Mentor: Marijana Kraljić Roković (mentor)
• Committee member: Marijana Kraljić Roković (predsjednik povjerenstva)
• Committee member: Helena Otmačić Ćurković (član povjerenstva)
• Committee member: Elvira Vidović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2024-02-23, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

U ovom radu provedena je ugradnja V2O5 u reducirani grafenov oksid (rGO) te karakterizacija dobivenog materijala u troelektrodnom sustavu. Osim toga provedena je sinteza i karakterizacija rGO papira u koji je ugrađen V2O5. Cilj rada bio je dobiti stabilan, savitljiv i samostojeći materijal koji će biti pogodan kao katoda u Zn-ionskim vodenim baterijama. Ispitivanje različitih rGO/V2O5 elektroda je pokazalo da se u 2 mol dm^-3 otopini ZnSO4 dobivaju veći kapaciteti u odnosu na 3 mol dm^-3 otopina ZnSO4. Isto tako pokazano je da su veći kapaciteti dobiveni kod elektroda s 50 % V2O5 nego kod elektroda s 70% V2O5 te da je materijal bolje iskorišten kad je manja masa aktivnog materijala nanesena na elektrodu. U ovom istraživanju pripravljen je GO papir s 70 % V2O5 koji je reduciran elektrokemijskim putem pri -1.4 V, pri čemu je grafenov oksid (GO) preveden u rGO.
U priređenoj bateriji Zn je imao ulogu anode dok je rGO/V2O5 korišten kao katoda. Svojstva Zn//rGO/V2O5 baterije su ispitana metodama kronoamperometrije (CA) i cikličke voltametrije (CV). U cikličkim voltamogramima zabilježeni su anodni i katodni strujni vrhovi koji odgovaraju redoks reakciji V2O5. Vrijednosti kapaciteta baterije, dobiveni metodom CV kreću se u rasponu od 41.06 mAh g^-1 do 311.85 mAh g^-1 pri brzinama promjene potencijala od 50 do 1 mV s^-1 Proveden je i galvanostatski proces punjenja i pražnjenja baterije. Vrijednosti kapaciteta baterije, zabilježeni tijekom galvanostatskog ispitivanja, kreću se u rasponu od 77.78 mAh g^-1 pri najvećoj struji (4.3 mA, 5.0 A g^-1 ), do 306.07 mAh g^-1 pri najmanjoj struji (0.7 mA, 0.8 A g^-1).

Abstract (english)

In this work, the incorporation of V2O5 into reduced graphene oxide (rGO) and the characterization of the obtained material in a three-electrode system were carried out.
In addition, the synthesis and characterization of rGO paper in which V2O5 was incorporated was carried out. The goal of the work was to obtain a stable, flexible and free-standing material that will be suitable as a cathode material in Zn-ion water based batteries. Examination of different rGO/ V2O5 electrodes showed that higher capacities are obtained in 2 mol dm^-3 ZnSO4 solution compared to 3 mol dm^-3 ZnSO4 solution. It was also shown that highercapacities were obtained with electrodes with 50% V2O5 than with electrodes with 70% V2O5 and that the material was better utilised when a smaller mass of active material was applied to the electrode. In this research, GO paper with 70% V2O5 was prepared and it was reduced electrochemically at -1.4 V, in order to convert graphene oxide (GO to rGO. In the prepared battery, Zn played the role of the anode while rGO/ V2O5 was used as the cathode. The properties of the Zn//rGO/ V2O5 battery were tested by chronoamperometry (CA) and cyclic voltammetry (CV) methods. In the cyclic voltammograms, anodic and cathodic current peaks corresponding to the V2O5 redox reaction were recorded. The battery capacity values, obtained by the CV method, range from 41.06 mAh g^-1 to 311.85 mAh g^-1 at scan rates from 50 to 1 mV s^-1. The galvanostatic process of charging and discharging the battery was also carried out. The battery capacity values, recorded during the galvanostatic test, range from 77.78 mAh g^-1 at the highest current (4.3 mA, 5.0 A g^-1 ),
to 306.07 mAh g^-1 at the lowest current (0 .7 mA, 0.8 A g^-1 ).

• Keywords: grafenov oksid; grafenski papir; V2O5; Zn-ionska baterija
• Keywords (english): graphene oxide; graphene paper; V2O5; Zn-ion battery
• Language: croatian
• URN:NBN: urn:nbn:hr:149:451607
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-01-01
• Created on: 2024-02-29 09:56:15