Formiranje inhibirajućih slojeva na elektrodi od kalcija u Ca(BF4)2/acetonitril elektrolitu

master's thesis

• Title (english): The formation of inhibiting layers on the calcium electrode in Ca(BF4)2/acetonitrile electrolyte
• Author: Paola Grobenski
• Mentor: Zoran Mandić (mentor)
• Committee member: Zoran Mandić (predsjednik povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Committee member: Vladimir Dananić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2024-09-13, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

U ovom radu ispitana je ćelija s metalnom kalcijevom anodom i katodom od aktivnog ugljika uz 0,5 M otopinu elektrolita Ca(BF4)2 u acetonitrilu, s ciljem razvijanja reverzibilne kalcijeve negativne elektrode. Za određivanje elektrokemijskih svojstava mjerenja su provedena u troelektrodnom sustavu metodama cikličke voltametrije i elektrokemijske impedancijske spektroskopije, a nastali sloj na elektrodi karakteriziran je infracrvenom spektroskopijom s Fourierovim transformacijama. Predloženi su modeli ekvivalentnih električnih krugova. Mjerenje napona otvorenog kruga pokazuje pad napona uslijed aktivacije elektrode, te postupni porast popraćen inhibiranjem površine zbog nastajanja SEI sloja. Iz rezultata cikličke voltametrije vidljivo je intenzivno otapanje kalcija, praćeno pojavom jamičaste korozije. Rezultati ukazuju na stvaranje SEI sloja koji prekriva površinu elektrode i onemogućuje difuziju Ca2+ iona, čineći elektrodu ireverzibilnom.

Abstract (english)

In this study, a cell with a metallic calcium anode and an activated carbon cathode was examined using a 0,5 M solution of Ca(BF4)2 electrolyte in acetonitrile, with the aim of developing a reversible calcium negative electrode. To determine the electrochemical properties, measurements were conducted in a three-electrode system using cyclic voltammetry and electrochemical impedance spectroscopy, and the resulting layer on the electrode was characterized by Fourier transform infrared spectroscopy. Equivalent electrical circuit models are proposed. The open circuit voltage measurement showed a drop in voltage due to electrode activation, followed by a gradual increase accompanied by surface inhibition due to the formation of a solid electrolyte interphase (SEI) layer. Cyclic voltammetry measurements reveal intense calcium stripping, accompanied by pitting corrosion.
The results indicate the formation of an SEI layer that covers the electrode surface and prevents the diffusion of Ca2+ ions, rendering the electrode irreversible.

• Keywords: kalcij; SEI sloj; reverzibilnost; multivalentne baterije
• Keywords (english): calcium; SEI layer; reversibility; multivalent batteries
• Language: croatian
• URN:NBN: urn:nbn:hr:149:058188
• 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: Open access
• Created on: 2024-09-24 12:48:58