20.500.12556/RUL-133336 Advanced Structural, chemical and electrochemical characterization of sodium layered cathode Advanced Structural, chemical and electrochemical characterization of sodium layered cathode Ta raziskovalni projekt je bil osredotočen na natrijeve okside kot katodne materiale za Na-ionske baterije. Pravzaprav imajo veliko prednosti, vendar se zaradi svoje nestabilnosti v atmosferskih razmerah ne uporabljajo široko. Glavni cilj teme je bil stabilizacija tega gradiva. Primerjali smo dva procesa sinteze za NaNi0,5Mn0,5O2. Klasična metoda je dala dobre rezultate, vendar je nova sintezna pot pod suhim zrakom pokazala material z veliko bolj zanimivimi lastnostmi glede cikličnosti in potenciala, tudi če bi bilo treba zmogljivost še povečati. Stabilnosti obeh vzorcev v zunanjem zraku je sledila rentgenska difrakcija. Ugotovljeno je bilo, da sinteza suhega zraka omogoča pridobivanje zračno stabilne spojine brez strukturne degradacije. Raziskane so bile elektrokemijske lastnosti pri visokem potencialu vzorca suhega zraka in ugotovljeno je bilo, da je pri 4,2 V udeležba redoks -reakcije kisika omogočila doseči kapaciteto 210 mAh/g. Kljub temu po nekaj ciklih ta pojav izgine in zmogljivost spet zbledi na 95 mAh/g. Stabilizacija tega pojava je bila raziskana zahvaljujoč sodelovanju z Umicorejem z vnosom cinka v material. This research project was focused on sodium layered oxides as cathode materials for Na-ion batteries. Actually, they present a lot of advantages, but they are not widely used because of their instability under atmosphere conditions. The stabilization of this material was the main objective of the topic. Two synthesis processes for NaNi0.5Mn0.5O2 have been compared. The classical method gave good results, but the new synthesis path under dry air showed a material with much more interesting properties in terms of cyclability and potential, even if the capacity still needed to be increased. The stability in ambient air of both samples was followed by X-ray diffraction. It has been found out the dry air synthesis allows to get an air-stable compound with no structural degradation. The electrochemical properties at high potential of the dry air sample were investigated, and it has been found out that at 4.2V, the participation of the oxygen redox reaction enabled to reach a capacity of 210 mAh/g. Nevertheless, after a few cycles, this phenomenon disappears and the capacity fades again to 95 mAh/g. The stabilization of this phenomenon has been investigated thanks to the collaboration with Umicore, by the introduction of Zinc within the material. Na-ionske baterije večplastni oksid zračna stabilnost anionski redoks Na-ion Batteries layered oxide air stability anionic redox true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2021-11-23 09:10:07 2021-11-23 09:10:13 2022-09-12 04:15:50 0000-00-00 00:00:00 2021 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1970-01-01 19481 Fakulteta za kemijo in kemijsko tehnologijo 0 0 1