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The chemical composition and microstructure of the solid electrolyte interphase (SEI) on lithium metal in ether-based electrolytes are investigated using X-ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectrometry (ToF-SIMS) and scanning electron microscopy (SEM). Electrolytes based on 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL) solvents with lithium bis(trifluoromethane)sulfonamide (LiTFSI) conducting salt are employed to passivate lithium surfaces for different periods of time. Two types of model experiments (immersion-type and galvanostatic current load) are performed to generate self- and current-induced SEIs. Reference measurements of predicted SEI components and an advanced XPS signal coupling method facilitate the deconvolution of the spectroscopic and spectrometric data. Both ether solvents showed specific SEI formation for each experimental setup. DME appears to decompose immediately on the lithium surface and forms a thin passivation film of various salts in a lithium-alkoxide framework. DOL shows a slow SEI formation of organic and inorganic salts revealing problems in the lithium surface protection. Under current load the reaction rate is increased in DME maintaining the three-dimensional microstructure. For DOL the current load leads to a multi-layer structure of organic host materials comprising LiTFSI and lithium fluoride. Finally, two-dimensional schematic pictures of the SEI microstructure are developed.

This paper describes a systematic comparison of the photoelectrochemical properties of mesoporous TiO2films prepared by the two most prevalent templating methods: The use of preformed, crystalline nanoparticles is generally considered advantageous compared to the usage of molecular precursors such as TiCl4, since the latter requires a separate heat treatment at elevated temperature to induce crystallization. However, our photoelectrochemical experiments clearly show that sol−gel derived mesoporous TiO2films cause an about 10 times higher efficiency for the water splitting reaction than their counterparts obtained from crystalline TiO2nanoparticles. This result indicates that for electrochemical applications the performance of nanoparticle-based metal oxide films might suffer from insufficient electronic connectivity.

Under strongly reducing conditions at high temperatures titania develops a specific surface morphology, comprising a regular array of fibers with a diameter in the sub‐micrometer range. By a chemical diffusion experiment in a defined oxygen potential gradient it is shown that this surface structuring is caused by a diffusion‐driven morphological instability of an advancing reaction front (surface). The kinetics of the process is analyzed in terms of linear transport equations. The conditions for the occurrence of the surface instability are discussed and the required materials properties are analyzed. The observed surface structuring is not restricted to titania, rather it has to occur in all nonstoichiometric compounds with predominant cation mobility.

Herein, the proof of concept of a sodium polysulfide battery consisting of two electrode chambers being separated by a solid electrolyte is described. The concept is suited for dissolved polysulfide cathodes and has the advantage that both half reactions can be optimized separately. The formation of solid sulfide discharge products is identified as the major limiting factor for cell cycling. This issue can be alleviated by adding solid P2S5. Further improvement can be achieved by replacing diglyme (2G) as the cathode compartment solvent with tetramethylurea (TMU). Using TMU, the cell cycles with Coulombic efficiencies >99% and capacities of 800 mAh g−1are maintained for at least 30 cycles. Viscosity, density, conductivity, and the electrochemical stability window values of the 2G‐ and TMU‐based electrolytes are compared. The latter shows higher viscosity (2.806 vs 1.603 mPa s), higher density (1.016 vs 0.996 g cc−1), and higher conductivity (4.27 vs 1.45 mS cm−1). The oxidative stability limit of the TMU electrolyte is 3.2 V versus Na+/Na, which is sufficient for polysulfide redox reactions. Vis spectroscopy is used to follow the electrode reaction. In case of TMU, the reaction is based on the redox activity of S3−•radicals (blue coloration of the catholyte solution). A Na/polysulfide cell concept with two electrolyte chambers separated by Na‐β″‐aluminate is discussed. The concept allows tailoring of the electrolyte formulation for both half reactions. For the positive electrode, sulfide precipitation is effectively mitigated using P2S5as an additive, and cycle life is improved using tetramethylurea (TMU) as a solvent. This proof‐of‐concept study could be interesting for developing stationary energy stores.

The chemical composition and microstructure of the solid electrolyte interphase (SEI) on lithium metal in ether-based electrolytes are investigated using X-ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectrometry (ToF-SIMS) and scanning electron microscopy (SEM). Electrolytes based on 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL) solvents with lithium bis(trifluoromethane)sulfonamide (LiTFSI) conducting salt are employed to passivate lithium surfaces for different periods of time. Two types of model experiments (immersion-type and galvanostatic current load) are performed to generate self- and current-induced SEIs. Reference measurements of predicted SEI components and an advanced XPS signal coupling method facilitate the deconvolution of the spectroscopic and spectrometric data. Both ether solvents showed specific SEI formation for each experimental setup. DME appears to decompose immediately on the lithium surface and forms a thin passivation film of various salts in a lithium-alkoxide framework. DOL shows a slow SEI formation of organic and inorganic salts revealing problems in the lithium surface protection. Under current load the reaction rate is increased in DME maintaining the three-dimensional microstructure. For DOL the current load leads to a multi-layer structure of organic host materials comprising LiTFSI and lithium fluoride. Finally, two-dimensional schematic pictures of the SEI microstructure are developed.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a well-established technique in material sciences but has not yet been widely explored for implementation in life sciences. Here, we demonstrate the applicability and advantages of ToF-SIMS analysis for the study of minerals and biomolecules in osseous tissue. The locally resolved analysis of fragment ions deriving from the sample surface enables imaging and differentiation of bone tissue and facilitates histology on non-stained cross sections. In a rat model, bilateral ovariectomy combined with either a multi-deficiency diet or steroid treatment was carried out to create osteoporotic conditions. We focused our study on the Ca content of the mineralized tissue and monitored its decline. Calcium mass images of cross sections show the progressive degenerative changes in the bone. We observed a decreased Ca concentration in the edge region of the trabeculae and a decline in the Ca/P ratio. Additionally, we focused on the non-mineralized matrix and identified fragment ions that are characteristic for the collagen matrix. We observed trabeculae with wide ranges of non-mineralized collagen for the diet group owing to an impaired mineralization process. Here, the advantage of coeval monitoring of collagen and minerals indicated an osteomalacic model rather than an osteoporotic one.

The title thin film electrodes with both a well‐defined mesoporous morphology and a nanocrystalline framework are synthesized by a polymer‐directed sol—gel route from a mixture of Ti(OBu)4, EtOH, AcOH, LiOAc, 2‐methoxyethanol, and a poly(ethylene‐co‐butylene)‐block‐poly(ethylene oxide) diblock copolymer as the structure‐directing agent (dip‐coating on polar substrates, 300 °C, 12 h).

[C13H28N2] 5Cu2.1In17.9S33 ·17H2O is synthesized from a mixture of CuS, In, S, 4,4′‐trimethylenedipiperidine, H2O, and ethyleneglycol (autoclave, 190 °C, 5 d, <90% yield) and used as a precursor for the preparation of the title film by pulsed laser deposition.

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