Morphometric study of hybridogenic species in Veronica subgenus Pseudolysimachium (Plantaginaceae)

We demonstrate the results of morphometric investigations of hybrids in Veronica subg. Pseudolysimachium (V. × altaica Kosachev und V. × kolyvanensis Kosachev et Shmakov) and their parents. Based on PCoA analysis with seven morphological characters, we reveal an intermediate position of the investigated hybrids and the most important taxonomic characters: ratio of length and width of the lamina of the upper leaves, height of plants, length of the longest corolla lobe and calyx lobe, presence of hairs on the calyx and their position, as well as the length of hairs on the internode below the inflorescence

SEI Formation on TiO2 Rutile

X-ray photoelectron spectroscopy (XPS) and symmetric electrochemical impedance spectroscopy (EIS) are carried out to identify and determine the nature of the solid electrolyte interface (SEI) formation on TiO2 rutile anodes in lithium ion batteries. The recorded XPS spectra (O1s, C1s, P2p and Li1s and Ti2p) evidence an SEI layer formation at 0.8 V vs. Li/Li+ in a TiO2/Li cell with a lithium reference and an organic electrolyte (LiPF6 in EC : DMC (1 : 1 by wt%)). When the cell is discharged down to 0.1 V, the SEI mainly consists of ether and carbonyl groups and some alcohol or alkoxide groups. Upon charge the SEI additionally evidences some carboxylic groups. EIS measurements exhibit an additional RQ element at 0.8 V, supporting the formation of the SEI at this potential. The EIS evaluation shows that the SEI is mainly formed in the first cycle but evolves further on in the following cycles

Lithium transition metal (Ti, Nb, V) oxide mesoporous thin films: contrasting results when attempting direct synthesis by evaporation-induced self assembly

This work investigates the possibility to prepare mesoporous thin films of Li-Ti, Li-Nb, Li-Nb-V and Li-V oxides through a direct sol-gel EISA route by dissolving a lithium salt in the precursor solution. Experimental conditions involve a hydrolysis molar ratio H2O/TM ~10 (TM = Ti,Nb,V) and the common Pluronic structuring agent P123 (EO20-PO70-EO20). Systematic formation of lithium-containing oxides as first-crystallizing phases points to a significant intermixture of lithium and transition metal ions in the inorganic network. In the case of Ti-based and Nb-based oxide films, addition of lithium to the precursor solution is compatible with the formation of amorphous mesoporous films at 350°C. On the contrary, addition of lithium has a detrimental effect on the notoriously difficult formation of vanadium-based mesostructured films: even when replacing half of the vanadium by niobium as a stabilizer, formation of mesostructured films has not been possible in the investigated range of experimental conditions.Inanoma

Cu/Li4Ti5O12 scaffolds as superior anodes for lithium-ion batteries

Nanostructured active materials with both high-capacity and high-rate capability have attracted considerable attention, but they remain a great challenge to be realized. Herein, we report a new route to fabricate a bicontinuous Cu/Li4Ti5O12 scaffold that consists of Li4Ti5O12 nanoparticles (LTO NPs) with highly exposed (111) facets and nanoporous Cu scaffolds, which enable simultaneous high-capacity and high-rate lithium storage. It is a 'one stone, two birds' strategy. When tested as the anode in lithium-ion batteries LIBs, Cu/LTO showed superior performance, such as a lifespan greater than 2000 cycles and an ultrafast charging time (<45 s). Notably, the ultrahigh capacity slightly larger than the theoretical value was also observed in Cu/LTO at low current density. Density functional theory calculations and detailed characterizations revealed that the highly exposed (111) facets on the edge are the reason for its unique storage mechanism (8a+16c), which is different from the transition between 8a and 16c in bulk LTO

Insights into solid electrolyte interphase formation on alternative anode materials in lithium-ion batteries

To gain new insights into the formation of the solid electrolyte interphase (SEI), as a basis for the safe and efficient use of new anode materials, we studied SEI formation on silicon and lithium titanate (LTO) anodes by electrochemical impedance spectroscopy (EIS) and ex situ X-ray photoelectron spectroscopy (XPS) measurements. While EIS measurements performed at equidistant voltage intervals provided insights into the SEI formation process, ex situ X-ray photoelectron spectroscopy (XPS) measurements supplied data on the chemical composition of the SEI layer. On silicon anodes we observed that resistance decreases in the second cycle which suggests the formation of a stable SEI with SiO2, Li4SiO4, LiF and different carbonates as its main components. On LTO anodes, however, resistance increases by a factor of two indicating incomplete SEI formation. Here LiF and different carbonates were identified as the SEI’s main components