Stabilization of Na-ion battery anode materials by aluminum oxide coatings
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
In this thesis work, hard-carbon anodes with a coating of Al2O3 in sodium-ion batteries have been investigated and compared with uncoated hard-carbon anodes. The Al2O3 coating on carbon particles was synthesized by a sol-gel method. The coating was characterized by SEM, XRD and XPS analysis. Electrochemical cells with hard-carbon anodes were assembled. The different electrolytes used were NaPF6 in EC:DEC (50:50), NaPF6 in EC:DEC:FEC (45:45:10) and NaPF6 in PC. The electrochemical behavior and the capacity of the cells were then characterized by cyclic voltammetry and galvanostatic cycling. Results from the galvanostatic cycling showed that the battery with the electrolyte NaPF6 in EC:DEC:FEC had a lower reversible capacity compared to the NaPF6 in EC:DEC electrolyte. Cyclic voltammetry results for the Al2O3 coated battery with the NaPF6 in PC electrolyte indicated that the aluminum from the coating reacted with the electrolyte. NaPF6 in EC:DEC was thus considered to be the most suitable electrolyte for coated hard-carbon anodes. The discharge capacity for the coated electrode in the NaPF6 in EC:DEC electrolyte during the first 5 cycles is slightly higher than for the uncoated electrode, but the capacity fading is also higher.
Place, publisher, year, edition, pages
2016. , 34 p.
UPTEC Q, ISSN 1401-5773 ; 16023
IdentifiersURN: urn:nbn:se:uu:diva-305616OAI: oai:DiVA.org:uu-305616DiVA: diva2:1038746
Subject / course
Master Programme in Materials Engineering
Kassman Rudolphi, ÅsaBrandell, Daniel