A simple method of analyzing the phase transition behavior of a Na-Sn battery using energy-dispersive X-ray spectroscopy

© The Korean Institute of Metals and Materials. Anode materials of the Na-Sn battery experience a series of phase transitions during charging and discharging. These phase transitions in many cases are accompanied by a large volume change in the electrode materials, which leads to pulverization, a major source of reducing the battery capacity. In contrast to the rich literature on the phase transition behaviors of the Li-Si battery, those of the Na-Sn battery are much less understood due to experimental difficulties in determining the chemical composition of the phases. In this study, we demonstrate a simple method of analyzing the composition of the reaction compounds of the Na-Sn battery electrodes using energy dispersive X-ray spectroscopy

A simple method of analyzing the phase transition behavior of a Na-Sn battery using energy-dispersive X-ray spectroscopy

© The Korean Institute of Metals and Materials. Anode materials of the Na-Sn battery experience a series of phase transitions during charging and discharging. These phase transitions in many cases are accompanied by a large volume change in the electrode materials, which leads to pulverization, a major source of reducing the battery capacity. In contrast to the rich literature on the phase transition behaviors of the Li-Si battery, those of the Na-Sn battery are much less understood due to experimental difficulties in determining the chemical composition of the phases. In this study, we demonstrate a simple method of analyzing the composition of the reaction compounds of the Na-Sn battery electrodes using energy dispersive X-ray spectroscopy

Understanding of electrochemical K+/Na+ exchange mechanisms in layered oxides

Ion-exchange reactions are commonly used to develop novel metastable electrode materials for alkali-ion batteries that cannot be synthesized using direct chemical reactions. In this study, the electrochemical K to Na ion-exchange reaction mechanisms in a layered KxCoO2 cathode as a model system were investigated using operando and ex situ structure characterization techniques. Some level of K ions was observed to remain in the layered structure during the electrochemical ion-exchange reactions. Interestingly, the K ions are well separated from the Na-rich phases in the discharged state, and they form an intermediate phase in which K and Na ions are mixed at the top of charge. We discovered that such residual K ions prevent the collapse of the layered structure in the high-voltage regime, thereby improving the cycling stability in a Na-battery system

Expanding the clinical and metabolic phenotype of DPM2 deficient congenital disorders of glycosylation.

Pathogenic alterations in the DPM2 gene have been previously described in patients with hypotonia, progressive muscle weakness, absent psychomotor development, intractable seizures, and early death. We identified biallelic DPM2 variants in a 23-year-old male with truncal hypotonia, hypertonicity, congenital heart defects, intellectual disability, and generalized muscle wasting. His clinical presentation was much less severe than that of the three previously described patients. This is the second report on this ultra-rare disorder. Here we review the characteristics of previously reported individuals with a defect in the DPM complex while expanding the clinical phenotype of DPM2-Congenital Disorders of Glycosylation. In addition, we offer further insights into the pathomechanism of DPM2-CDG disorder by introducing glycomics and lipidomics analysis.status: Published onlin