Analysis of magnetic characteristics of three-phase reactor made of grain-oriented silicon steel

Flux and iron loss distributions of three-phase reactor are analyzed using the finite element method considering 2-D B-H curves and iron losses in arbitrary directions which are measured up to high flux density. It is shown that the total iron loss of reactor yoke does not change so much by the yoke dimension, although the local iron loss is increased when the width of yoke is decreased. The experimental verification of flux and iron loss distributions are also carried out </p

Destabilized Passivation Layer on Magnesium-Based Intermetallics as Potential Anode Active Materials for Magnesium Ion Batteries

Passivation of magnesium metal anode is one of the critical challenges for the development of magnesium batteries. Here we investigated the passivation process of an intermetallic anode: Mg3Bi2 synthesized by solid-state and thin film process. The Mg3Bi2 composite electrode shows excellent reversibility in magnesium bis(trifluoromethansulfonylamide) dissolved in acetonitrile, while Mg3Sb2, which has same crystal structure and similar chemical properties, is electrochemically inactive. We also fabricated the Mg3Bi2 thin film electrodes, which show reversibility with low overpotential not only in the acetonitrile solution but also glyme-based solutions. Surface layer corresponding to the decomposed TFSA anion is slightly suppressed in the case of the Mg3Bi2 thin film electrode, compared with Mg metal. Comparative study of hydrolysis process of the Mg3Bi2 and the Mg3Sb2 suggests that the both intermetallic anodes are not completely passivated. The bond valence sum mapping of the Mg3Bi2 indicates that the fast Mg2+ diffusion pathway between 2d tetrahedral sites is formed. The electrochemical properties of the Mg3Bi2 anode is mainly due to the less passivation surface with the fast Mg2+ diffusion pathways

Improved Cycling Performance of Intermetallic Anode by Minimized SEI Layer Formation

Electrochemical properties of bismuth composite electrode are investigated as potential negative electrode for lithium ion batteries. The electrode shows severe capacity decay typically observed in the case of alloy-based materials, using a conventional carbonate-based electrolyte solution. The electrode maintained only 10% of the theoretical capacity after 25 cycles of lithiation/delithiation process. The electrode shows poor coulombic efficiency of 98% of reversible capacity, even after 50 cycles. The bismuth electrode cycled in the LiBH4 electrolyte maintained relatively large bismuth particles compared with the electrode cycled in the carbonate-based electrolyte. In situ FTIR study proved the carbonate-based electrolyte forms passivation layer <0.7 V vs. Li, while the LiBH4 electrolyte does not passivate the electrode surface