20.500.12556/RUL-135999 Magnesium insertion and related structural changes in spinel-type manganese oxides Commercial LiMn$_2$O$_4$ powder was used as the base material for probing magnesiation, cycling behavior, and structural stability/changes in (Mg$_x$Li$_{1-x}$)Mn$_2$O$_4$ spinel cathodes in aqueous Mg(NO$_3$)$_2$ and non-aqueous Mg(TFSI)$_2$/diglyme and Mg(Mg(HFIP)$_2$ − 2Al(HFIP)$_3$/diglyme electrolytes. Each of the samples was delithiated and, then, magnesiated electrochemically in the corresponding electrolyte. The electrochemical activity of the cathode cycled in aqueous electrolyte showed high reversibility during the oxidation process; however, large polarization and a relatively fast capacity fading were the culprits of the system. Cycling in Mg(TFSI)2/diglyme electrolyte solution resulted in much lower initial specific capacity compared to an aqueous counterpart, as well as a much faster failure. On the other hand, cycling in Mg(HFIP)$_2$ − 2Al(HFIP)$_3$/diglyme electrolyte solution demonstrated excellent cycling performance with very low polarization in the first cycles. The observed voltages for this system were near theoretical values for the Mg insertion. Although the electrochemical measurements suggest reversible magnesiation, detailed structural and analytical STEM investigation revealed the differences in the atomic structure and Mn valence of all three cathode samples upon cycling. The electrolytes’ influence on the structural rearrangement during Mg insertion is discussed for each of the three systems. spinel manganese lithium magnesium TEM electrochemistry spinel mangan litij magnezij TEM elektrokemija true false true Angleški jezik Slovenski jezik Članek v reviji 2022-04-06 09:34:31 2022-04-06 09:34:31 2022-09-15 04:13:08 0000-00-00 00:00:00 2021 0 0 12 str. iss. 8, art. 984 Vol. 11 Aug. 2021 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.1:544.6 2073-4352 10.3390/cryst11080984 78444291 RAZ_Robba_Ana_2021.pdf RAZ_Robba_Ana_2021.pdf 1 E2982C6869D7530712CDEBBA0E416B23 1a4f8a7307651c57ee0d197781aa579c3ad4c7aa64d5815cc7502b6307fa31c7 45c68f95-b57c-11ec-8aca-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=155381 https://www.mdpi.com/2073-4352/11/8/984 0 f5fdfc80-b57b-11ec-8aca-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=155380 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0