In situ SEM observation of a lithium deposition and dissolution process in an all-solid-state lithium metal battery using a sulfide-based solid electrolyte (SE) was carried out. We revealed visually that the morphology of lithium deposition varies with the operating current densities. At current densities higher than 1 mA cm⁻², local lithium deposition triggers large cracks, leading to a decrease in the reversibility of lithium deposition and dissolution. On the other hand, at a low current density of 0.01 mA cm⁻², its homogeneous deposition, which enables the reversible deposition and dissolution, hardly brings about the occurrence of unfavorable cracks. These results suggest that homogeneous lithium deposition on the SE and the suppression of the growth of lithium metal along the grain boundaries inside the SE are keys to achieve the repetitive lithium deposition and dissolution reaction without deterioration of the SE.

The effect of the viscosity of room temperature molten salt (RTMS) electrolyte has been investigated on the performance of dye-sensitized solar cell (DSSC). Both the short circuit photocurrent and conversion efficiency are increased with decreasing the viscosity of RTMS as in the case of conventional electrolytes. The conversion efficiency of 2.1% observed for the cell of EMIm-F·2.3HF is the highest value reported for all the DSSC consisted of RTMS.

Transcellular Mg²⁺ transport across epithelia, involving both apical entry and basolateral extrusion, is essential for magnesium homeostasis, but molecules involved in basolateral extrusion have not yet been identified. Here, we show that CNNM4 is the basolaterally located Mg²⁺ extrusion molecule. CNNM4 is strongly expressed in intestinal epithelia and localizes to their basolateral membrane. CNNM4-knockout mice showed hypomagnesemia due to the intestinal malabsorption of magnesium, suggesting its role in Mg²⁺ extrusion to the inner parts of body. Imaging analyses revealed that CNNM4 can extrude Mg²⁺ by exchanging intracellular Mg²⁺ with extracellular Na⁺. Furthermore, CNNM4 mutations cause Jalili syndrome, characterized by recessive amelogenesis imperfecta with cone-rod dystrophy. CNNM4-knockout mice showed defective amelogenesis, and CNNM4 again localizes to the basolateral membrane of ameloblasts, the enamel-forming epithelial cells. Missense point mutations associated with the disease abolish the Mg²⁺ extrusion activity. These results demonstrate the crucial importance of Mg²⁺ extrusion by CNNM4 in organismal and topical regulation of magnesium. Magnesium is an essential element for living organisms. Its absorption occurs at the intestine through the barrier comprised of epithelial cells. In this process, transcellular Mg²⁺ transport across epithelia, involving both entry from one side and extrusion from the other side, is important. Previous studies have revealed the role of Mg²⁺-permeable channel protein in Mg²⁺ entry into the epithelial cells. However, the identity of proteins involved in Mg²⁺ extrusion to the inner parts of body has remained unknown. Mice genetically engineered not to express CNNM4, which localizes to the epithelial membrane facing to the inner parts of body, show hypomagnesemia due to the defect in magnesium absorption. Functional analyses using culture cells directly reveal that CNNM4 can extrude intracellular Mg²⁺ to the outside of cells. These results indicate that CNNM4 mediates transcellular Mg²⁺ transport across the intestinal epithelia. Furthermore, we also show that these CNNM4-lacking mice also have a defect in amelogenesis, which is consistent with the disease symptoms of Jalili syndrome that is known to be caused by mutations in the CNNM4 gene.

Reaction of 1-ethyl-3-methylimidazolium chloride (EMICl) and anhydrous hydrogen fluoride gives a nonvolatile, room temperature molten salt, <mml:math display="inline"><mml:mo>EMIF</mml:mo><mml:mo>⋅</mml:mo><mml:mn>2.3</mml:mn><mml:mo>HF</mml:mo><mml:mo>.</mml:mo></mml:math>EMIF⋅2.3HF. The elemental analysis, vibrational, and nuclear magnetic resonance spectroscopy suggests the presence of oligomeric anions, <mml:math display="inline"><mml:mo stretchy="false">(</mml:mo><mml:mo>HF</mml:mo><mml:msub><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:msup><mml:mo>F</mml:mo><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup></mml:math>(HF)nF− in the salt. The liquid is stable in air and able to be handled in a Pyrex glass vessel. The specific conductivity is 100 mS cm⁻¹ at 298 K, which is extremely high compared with other salts of this kind. The high conductivity is realized by its low viscosity (4.85 cP at 298 K). The liquid temperature ranges from 180 to 350 K, and electrochemical window is about 3.2 V when a vitreous carbon is used for the electrode material. © 2001 The Electrochemical Society. All rights reserved.