Određivanje optimalne koncentracije ZnSO4 elektrolita u grafen/cink hibridnom superkondenzatoru

undergraduate thesis

• Title (english): Determination of optimal ZnSO4 electrolyte concentration for graphene/zinc hybrid supercapacitor
• Author: Dora Lovrenčić
• Mentor: Marijana Kraljić Roković (mentor)
• Committee member: Marijana Kraljić Roković (predsjednik povjerenstva)
• Committee member: Helena Otmačić Ćurković (član povjerenstva)
• Committee member: Iva Movre Šapić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2022-09-08, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

U ovom radu provedena je sinteza i ispitivanje reduciranog grafenovog oksida (rGO) i rGO modificiranog acetilenskim crnilom (AC) s ciljem izrade superkondenzatora i hibridnog superkondenzatora. Ispitivanje je provedeno u troelektrodnom sustavu korištenjem metode cikličke voltametrije (CV) i elektrokemijske impedancijske spektroskopije (EIS). Modificirane elektrode sadržavale su 10 % i 20 % acetilenskog crnila. Utvrđeno je da sve elektrode pokazuju dobra kapacitivna svojstva u otopini Na2SO4 i ZnSO4 te da je u otopini ZnSO4 moguće istaložiti cink. Korištene su tri različite koncentracije ZnSO4 elektrolita pri čemu je najbolja reverzibilnost postignuta u otopini najveće koncentracije. Površine elektroda su snimljene optičkim mikroskopom čime je utvrđeno da poroznost sloja raste s dodatkom AC. Osim modificiranih elektroda, u ovom radu je uspješno priređen i rGO papir modificiran s 20 % AC (rGO/20 % AC papir). Dobiveni rGO/20 % AC papir korišten je kao aktivni materijal u superkondenzatoru s 0,5 mol dm-3 Na2SO4 kao osnovnim elektrolitom i hibridnom superkondenzatoru s 1 mol dm-3 ZnSO4 kao osnovnim elektrolitom. Sastavljeni superkondenzatori testirani su metodom CV i EIS te su ispitani tijekom 1000 ciklusa punjenja/pražnjenja. Dobivene vrijednosti specifičnih kapaciteta u slučaju superkondenzatora iznose od 20,15 do 21,62 F g^-1, dok hibridni superkondenzator ima nešto veće vrijednosti, od 28,21 do 31,78 F g^-1. Veće vrijednosti specifičnih kapaciteta kod hibridnog superkondenzatora dokaz su da je on uspješno priređen.

Abstract (english)

In this work, the synthesis and testing of reduced graphene oxide (rGO) and rGO modified with acetylene black (AC) was carried out with the aim of making a supercapacitor and a hybrid supercapacitor. The testing was conducted in a three electrode system using the method of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The modified electrodes contained 10 % and 20 % acetylene black. It was determined that all electrodes show good capacitive properties in Na2SO4 and ZnSO4 solutions. Also, it was possible to precipitate zinc in ZnSO4 solution. Three different concentrations of ZnSO4 electrolyte were used, whereby the best reversibility was achieved in the solution with the highest concentration. The surfaces of the electrodes were recorded with an optical microscope, which indicated that the porosity of the layer increases with the addition of AC. Except the modified electrodes, rGO paper modified with 20 % AC (rGO/20% AC paper) was also successfully prepared in this work. The obtained rGO/20 % AC paper was used as an active material in a supercapacitor containing 0.5 mol dm-3 Na2SO4 electrolyte and in a hybrid supercapacitor containing 1 mol dm-3 ZnSO4 as the base electrolyte. The assembled supercapacitors were tested using the CV and EIS methods. Additionally, they were tested during 1000 charge/discharge cycles. For the supercapacitor, the obtained values of specific capacitance range from 20.15 to 21.62 F g^-1, while the hybrid supercapacitor has slightly higher values, from 28.21 to 31.78 F g^-1. The higher values of the specific capacitance of the hybrid supercapacitor are proof that it has been successfully prepared.

• Keywords: acetilensko crnilo; cink; grafen; hibridni superkondenzator; rGO papir
• Keywords (english): acetylene black; graphene; hybrid supercapacitor; rGO paper; zinc
• Language: croatian
• URN:NBN: urn:nbn:hr:149:156651
• Study programme: Title: Applied Chemistry - Undergraduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2023-09-01
• Created on: 2023-03-03 12:22:39