20.500.12556/RUL-186965 Termo-odzivno sproščanje litijeve soli iz mikrokapsul v litij-ionskih baterijah Thermo-responsive release of lithium salt from microcapsules in lithium-ion batteries Kljub temu da se v sodobni družbi tehnologija litij-ionskih baterij že dolgo uspešno razvija in uporablja za učinkovito shranjevanje energije, se še vedno iščejo strategije, osredotočene na problematiko neizogibnega krajšanja življenjske dobe celice zaradi degradacijskih procesov. Eden ključnih je izguba litijevega inventarja, ki se ireverzibilno porablja predvsem pri tvorbi medfaznih plasti na katodi in anodi ter v reakcijah na njih. V diplomskem delu je bila raziskana strategija kompenzacije te izgube s pomočjo mikrokapsul, ki po termični aktivaciji iz jedra sprostijo litijevo žrtveno sol. Mikrokapsule v jedru vsebujejo litijev skvarat, sledi porozna lupina iz SiO2, ta pa je obdana s termoodzivnim polimerom, ki je zaslužen za časovno nadzorovano sprostitev soli ob povišani temperaturi. Mikrokapsule so bile v masnem deležu 2 ut. % med pripravo elektrode vgrajene v katodni kompozit na osnovi litij-mangan-železovega fosfata (LMFP), kot anoda pa je bila uporabljena elektroda iz naravnega grafita. LMFP v primerjavi s sorodnim litij-železovim fosfatom (LFP) omogoča obratovanje celice pri višji povprečni napetosti, kar ji posledično daje večjo energijsko gostoto. Za karakterizacijo katodnega kompozita sta bili uporabljeni tehniki elektronska vrstična mikroskopija (SEM) in energijsko-disperzijska rentgenska spektroskopija (EDX). Elektrokemijsko karakteriziranje celic tako polčlenov kot polnih členov je bilo izvedeno z metodo galvanostatskega cikličnega merjenja z omejitvijo potenciala (GCPL). Strategija je bila kvalitativno ocenjena s primerjavo različnih testnih režimov, poleg tega pa je bil na kratko predstavljen tudi vpliv razmerja med kapaciteto anode in katode (N/P) na delovanje celice po termični aktivaciji. Although lithium-ion battery technology has already been successfully developed and used in modern society for efficient energy storage over a long period of time, strategies are still being sought to address the problem of the inevitable shortening of cell lifetime caused by degradation processes. One of the key contributors is the loss of lithium inventory, which is irreversibly consumed primarily through the formation of interphase layers on the cathode and anode and through reactions occurring on them. This thesis investigates a strategy for compensating this loss by means of microcapsules that, upon thermal activation, release a sacrificial lithium salt from their core. The core of the microcapsules contains lithium squarate, enclosed by a porous SiO2 shell, which is in turn surrounded by a thermo-responsive polymer responsible for the time-controlled release of the salt at elevated temperature. During electrode preparation, the microcapsules were incorporated into the cathode composite, based on lithium manganese iron phosphate (LMFP), at a mass fraction of 2 wt.%, while a natural graphite electrode was used as the anode. Compared with the related lithium iron phosphate (LFP), LMFP enables cell operation at a higher average voltage, which consequently results in a higher energy density. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the cathode composite. Electrochemical characterization of both half-cells and full cells was performed using the galvanostatic cycling with potential limitation (GCPL) method. The strategy was qualitatively evaluated by comparing different test regimes, and the effect of the anode-to-cathode capacity ratio (N/P) following thermal activation was also briefly presented. litij-ionska baterija LMFP mikrokapsule litijev skvarat termična aktivacija lithium-ion battery LMFP microcapsules lithium squarate thermal activation true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-09-08 08:45:02 2026-09-08 08:45:13 2026-09-09 04:22:05 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1970-01-01 26111 Zibert_Mark_-_Termo-odzivno_sproscanje_litijeve_soli_iz_mikrokapsul_v_litij-ionskih_baterijah.pdf Zibert_Mark_-_Termo-odzivno_sproscanje_litijeve_soli_iz_mikrokapsul_v_litij-ionskih_baterijah.pdf 1 52EFB328BB13E36EABBDA22E49E785A7 a4b404209d9d8e7cb49dd4da8320dc0104ba4d3b19b86ec0fb80e713a508fdfd dabf9983-ab50-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=246373 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0