Uporaba trdnih elektrolitov na osnovi Li$_{5,67}$La$_3$Zr$_{1,48}$Ta$_{0,52}$O$_{12}$ v Li-ion akumulatorjih

Jerovšek, Jan (author), Dominko, Robert (mentor)

Uporaba trdnih elektrolitov predstavlja obetavno tehnologijo za nove generacije Li-ion akumulatorjev, ki omogočajo izboljšanje varnosti, stabilnosti in energijske gostote. Raziskave na tem področju se osredotočajo na razvoj materialov, ki omogočajo visoko ionsko prevodnost in stabilnost v širokem temperaturnem in napetostnem območju. V magistrskem delu smo izvajali analizo polimernih elektrolitov na osnovi PEO-LiTFSI, kompozitnih elektrolitov na osnovi PEO-LiTFSI in Ta-LLZO ter keramičnih elektrolitov na osnovi Ta-LLZO keramike. Na podlagi LSV meritev smo ugotovili, da kompozitni elektroliti na osnovi PEO-LiTFSI in Ta-LLZO izkazujejo izboljšano napetostno stabilnost (5,5 V proti Li/ Li$^+$), kar omogoča integracijo kompozitnih elektrolitov z visokonapetostnimi katodnimi materiali. Na podlagi meritev ionske prevodnosti z EIS smo ugotovili nižje ionske prevodnosti kompozitnih elektrolitov v primerjavi s polimernim PEO-LiTFSI elektrolitom (3×10$^{-4}$ S cm$^{-1}$ in 2×10$^{-3}$ S cm$^{-1}$). Polimerne in kompozitne elektrolite smo v konfiguraciji z LFP in LTO analizirali z galvanostatskimi meritvami, kjer smo ugotovili, da kompozitni elektroliti omogočajo stabilnejše delovanje kot polimerni elektrolit. Prav tako smo v sklopu magistrske naloge izdelali keramični elektrolit, kjer smo optimizirali sestavo keramične suspenzije in sintranje. Tako pripravljeno keramično membrano smo analizirali z uporabo XRD in SEM.

• Language: Slovenian
• Keywords: trdni elektroliti, Li-ion akumulatorji, Ta-LLZO
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2024
• PID: 20.500.12556/RUL-161260
• COBISS.SI-ID: 207421443
• Publication date in RUL: 09.09.2024

Secondary language

• Language: English
• Title: Solid-state electrolytes based on Li$_{5,67}$La$_3$Zr$_{1,48}$Ta$_{0,52}$O$_{12}$ for use in Li-ion batteries

Abstract

The use of solid-state electrolytes represents a promising technology for the next generation of Li-ion batteries, offering improved safety, stability and energy density. Research in this field focuses on the development of materials that provide high ionic conductivity and stability across a wide temperature and potential range. In this master thesis we have analysed polymer electrolytes based on PEO-LiTFSI, composite electrolytes based on PEO-LiTFSI and Ta-LLZO and ceramic electrolytes based on Ta-LLZO ceramics. Based on LSV measurements, we found that composite electrolytes based on PEO-LiTFSI and Ta-LLZO demonstrate improved voltage stability (5.5 V vs. Li/ Li$^+$), which enables the integration of composite electrolytes with high-voltage cathode materials. Measurements of ionic conductivity using EIS revealed lower ionic conductivities of the composite electrolytes compared to the polymer PEO-LiTFSI electrolyte (3×10$^{-4}$ S cm$^{-1}$ and 2×10$^{-3}$ S cm$^{-1}$). Polymer and composite electrolytes were analyzed in configurations with LFP and LTO using galvanostatic measurements, and we found that composite electrolytes provide more stable performance than the polymer electrolyte. Furthermore, as part of the thesis, we fabricated a ceramic electrolyte and optimised the composition for the tape casting and sintering process. The resulting ceramic membrane was analysed with XRD and SEM.

• Keywords: Solid-State electrolytes, Li-ion batteries, Ta-LLZO