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Abstract Traditional linear carbonates including dimethyl carbonate (DMC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC) were investigated as co-solvents for the dimethyl-2,5-dioxahexane carboxylate (DMOHC)-based electrolyte in Na0.97Ca0.03[Mn0.39Fe0.31Ni0.22Zn0.08]O2 (NCMFNZO)/hard carbon (HC) pouch cells. The EMC-containing cell displays excellent electrochemical performance, exhibiting only a 1.6 mAh irreversible capacity loss during 500 hours of storage at 4V and 40°C, and maintaining over 80% capacity retention after 200 cycles up to 4V at 40°C. Severe gas evolution and Na plating issues are present in all the tested systems. 

Despite substantial research efforts in developing high-voltage sodium-ion batteries (SIBs) as high-energy-density alternatives to complement lithium-ion-based energy storage technologies, the lifetime of high-voltage SIBs is still associated with many fundamental scientific questions. In particular, the structure phase transition, oxygen loss, and cathode–electrolyte interphase (CEI) decay are intensely discussed in the field. Synchrotron X-ray and neutron scattering characterization techniques offer unique capabilities for investigating the complex structure and dynamics of high-voltage cathode behavior. In this review, to accelerate the development of stable high-voltage SIBs, we provide a comprehensive and thorough overview of the use of synchrotron X-ray and neutron scattering in studying SIB cathode materials with an emphasis on high-voltage layered transition metal oxide cathodes. We then discuss these characterizations in relation to polyanion-type cathodes, Prussian blue analogues, and organic cathode materials. Finally, future directions of these techniques in high-voltage SIB research are proposed, including CEI studies for polyanion-type cathodes and the extension of neutron scattering techniques, as well as the integration of morphology and phase characterizations. 

Methylamine (CH 3 NH 2 ) and methanimine (CH 2 NH) represent essential building blocks in the formation of amino acids in interstellar and cometary ices. In our study, by exploiting isomer selective detection of the reaction products via photoionization coupled with reflectron time of flight mass spectrometry (Re-TOF-MS), we elucidate the formation of methanimine and ethylenediamine (NH 2 CH 2 CH 2 NH 2 ) in methylamine ices exposed to energetic electrons as a proxy for secondary electrons generated by energetic cosmic rays penetrating interstellar and cometary ices. Interestingly, the two products methanimine and ethylenediamine are isoelectronic to formaldehyde (H 2 CO) and ethylene glycol (HOCH 2 CH 2 OH), respectively. Their formation has been confirmed in interstellar ice analogs consisting of methanol (CH 3 OH) which is ioselectronic to methylamine. Both oxygen-bearing species formed in methanol have been detected in the interstellar medium (ISM), while for methanimine and ethylenediamine only methanimine has been identified so far. In comparison with the methanol ice products and our experimental findings, we predict that ethylenediamine should be detectable in these astronomical sources, where methylamine and methanimine are present. 

Abstract The hitherto elusive monobridged Ge(μ‐H)GeH (X¹A′) molecule was prepared in the gas phase by bimolecular reaction of atomic germanium with germane (GeH₄). Electronic structure calculations revealed that this reaction commenced on the triplet surface with the formation of a van der Waals complex, followed by insertion of germanium into a germanium‐hydrogen bond over a submerged barrier to form the triplet digermanylidene intermediate (HGeGeH₃); the latter underwent intersystem crossing from the triplet to the singlet surface. On the singlet surface, HGeGeH₃predominantly isomerized through two successive hydrogen shifts prior to unimolecular decomposition to Ge(μ‐H)GeH isomer, which is in equilibrium with the vinylidene‐type (H₂GeGe) and dibridged (Ge(μ‐H₂)Ge) isomers. This reaction leads to the formation of cyclic dinuclear germanium molecules, which do not exist on the isovalent C₂H₂surface, thus deepening our understanding of the role of nonadiabatic reaction dynamics in preparing nonclassical, hydrogen‐bridged isomers carrying main group XIV elements.