Insertion reactions are of key importance for Li ion and hydrogen storage materials energy devices. The particle size dependence insertion has been investigated lithiated anatase TiO2, revealing progressively increasing capacity Li-ion solubility decreasing sizes, strongly deviating from the expected Li-rich Li-poor phase separation as occurs in bulk material. diagram alters significantly, changing properties already at sizes large 40 nm. A rationale is found surface strain that between...

The nanosized Li(4+x)Ti(5)O(12) spinel is investigated by electrochemical (dis)charging and neutron diffraction. near-surface environment of the particles allows higher Li ion occupancies, leading to a larger storage capacity. However, too high surface lithium leads irreversible capacity loss, most likely due reconstruction or mechanical failure. A mechanism where large ultimately rationalizes existence an optimal particle size. Recent literature attributes curved voltage profiles, reduced...

Water stable methyl modified MOF-5s have been synthesized via a solvothermal route. Methyl- and 2,5-dimethyl-modified show the same topology hydrogen uptake capability as that of MOF-5. The H2 capacity MOF-5, however, drops rapidly when exposed to ambient air, whereas capacities remain for 4 days.

The substantial influence of crystallite size on the properties Li-ion storage materials has spurred intensive research in emerging area nanoionics. development nanoscale offers a promising strategy to increase energy capabilities batteries, potentially making them suitable for electric vehicles. Nanosizing, which increases surface area, enhances importance interfaces and surfaces directly observable such as voltage profile phase diagram. As result, nanosized can show improved properties,...

7Li magic angle spinning solid-state nuclear magnetic resonance is applied to investigate the lithium local environment and ion mobility in tetragonal anatase TiO2 orthorhombic titanate Li0.6TiO2. Upon insertion, an increasing fraction of material changes its crystallographic structure from Phase separation occurs, as a result, Li-rich phase coexisting with Li-poor containing only small Li amounts ≈ 0.01. In both lattice, found be hopping over available sites activation energies 0.2 0.09 eV,...

Intercalation of Li in TiO2 anatase results a phase separation Li-poor and Li-rich phase. The local lithium configuration the coexisting crystallographic phases is resolved by detailed analysis neutron diffraction data. In each phases, two distinct positions within octahedral interstices are found, with temperature-dependent occupancy. A combination quasi-elastic scattering force field molecular dynamics simulations shows that hopping on picosecond time scale between sites interstices. also...

The reaction of hydrogen gas with magnesium metal, which is important for storage purposes, enhanced significantly by the addition catalysts such as Nb and V using nanostructured powders. In situ neutron diffraction on MgNb0.05 MgV0.05 powders give a detailed insight catalyst phases that exist during various stages cycling. During early stage hydriding (and deuteriding), MgH1<x<2 phase observed, does not occur in bulk MgH2 and, thus, appears characteristic small particles. abundant H...

The dopant mechanisms allowing high power in olivine compounds have been hotly debated. Here we conclusively prove that olivines are distinguished by having limited lattice solubility for aliovalent dopants (less than 3%). This is compensated lithium nonstoichiometry leading to an iron valence +2.

The zero strain Li4+xTi5O12 material as a two-phase system is, in contrast to common knowledge, unstable at room temperature (see figure), and it is fast Li insertion that leads kinetically induced effective reaction. solid-solution-induced disorder, resulting from the mixed 8a/16c occupation, most likely responsible for high rate capabilities Li4+xTi5O12.

Li(4)Ti(5)O(12) spinel as Li-ion electrode material combines good capacity, excellent cycleability with a high rate capability. Although the potential of about 1.56 V vs Li is relatively high, these features make it anode choice for state art power batteries. flat voltage profile reflects two-phase reaction during lithiation, small change in lattice parameters upon lithiation ("zero-strain" property) leads to solid solution equilibrium, recently demonstrated diffraction. In this study,...

Single-walled carbon nanotubes (SWNT) were reported to have record high hydrogen storage capacities at room temperature, indicating an interaction between and matrix that is stronger than known before. Here we present a study of the with activated charcoal, nanofibers, SWNT disproves these earlier reports. The capacity materials correlates surface area material, charcoal having largest. appear relatively low accessible due bundling tubes; does not enter voids tubes in bundles....

Thermodynamic theory reveals the impact of surface and interface energies on equilibrium properties solubility limits interstitial ions in nanosized crystallites. Applied to LixFePO4 especially energy contributions play important roles, their effect explains observations narrowing electrochemically measured miscibility gaps nanostructured electrodes.

Amorphous titanium oxide nanoparticles were prepared from isopropoxide. In situ measurements reveal an extraordinary high capacity of 810 mAh/g on the first discharge. Upon cycling at a charge/discharge rate 33.5 mA/g, this gradually decreases to 200 after 50 cycles. The origin fading was investigated using X-ray absorption spectroscopy and solid-state nuclear magnetic resonance. These that large fraction total amount consumed Li atoms is due reaction species adsorbed surface , explaining...

Because of its stability, nanosized olivine LiFePO4 opens the door toward high-power Li-ion battery technology for large-scale applications as required plug-in hybrid vehicles. Here, we reveal that thermodynamics first-order phase transitions in nanoinsertion materials is distinctly different from bulk demonstrated by decreasing miscibility gap appears to be strongly dependent on overall composition LiFePO4. In contrast our common thermodynamic knowledge, dictates solubility limits...

The structural behavior of both micro- and nanosized TiO2 rutile upon Li-ion insertion was determined from neutron diffraction measurements. In the solid solution regime in microsized rutile, which extends up to x ≈ 0.07 Li/Ti, Li ions mainly reside at tetrahedral position low temperatures octahedral higher temperatures. A rationale this effect found influence lattice dynamics, illustrated by molecular dynamics simulations diffusion structure. Maximum (chemically) lithiated microrutile...

Upon lithium insertion in the pristine TiO2 anatase phase theoretical maximum of LiTiO2 can be reached crystallite sizes less than ∼10 nm, whereas bulk compositions appear limited to Lix≈0.6TiO2 at room temperature. Both X-ray absorption spectroscopy (XAS) and ab initio calculations have been applied probe electronic structure newly formed phase. These results indicate that a large majority Li-2s electrons reside Ti-3d(t2g)/4s hybridized site. About 10% these are transferred non-localized...

Abstract Black phosphorus (BP) has received increasing research attention as an anode material in sodium‐ion batteries (SIBs), owing to its high capacity, electronic conductivity, and chemical stability. However, it is still challenging for BP‐based SIB anodes achieve a electrochemical performance utilizing cost‐effective materials synthetic methods. This work presents based on BP−carbon nanocomposite synthesized from commercial red low‐cost super P carbon black. Intimate interactions...

Silicon nanoparticles produced by expanding thermal plasma chemical vapor deposition show reversible electrochem­ical sodium uptake at room temperature. Sodiation of silicon occurs in a two-phase equilibrium reaction; whereas desodiation involves solid solution Na1−xSi (0 < x 1). nanomaterials appear as promising anode materials for sodium-ion batteries the first time. As service to our authors and readers, this journal provides supporting information supplied authors. Such are peer reviewed...

It is shown that the dissolution of elemental sulfur into, and its diffusion through, electrolyte allows cycling lithium–sulfur batteries in which initially far removed electrically insulated from current collector. These findings help to understand why liquid can be efficiently cycled, despite extremely insulating properties sulfur. As a service our authors readers, this journal provides supporting information supplied by authors. Such materials are peer reviewed may re-organized for online...

Large scale implementation of solar and wind powered renewable electricity generation will use up to continent sized connected grids built distribute the locally fluctuating power. Systematic power output variation then become manifest since has an evident diurnal period, but also surface winds—which are driven by temperatures—follow a periodic behavior lagging about 4 h in time. On ordinary day strong varying results when combining on such grid. Comparison with possible demand patterns...

Abstract Phosphorus and tin phosphide based materials that are extensively researched as the anode for Na‐ion batteries mostly involve complexly synthesized sophisticated nanocomposites limiting their commercial viability. This work reports a Sn 4 P 3 ‐P (Sn:P = 1:3) @graphene nanocomposite with novel facile mechanochemical method, which exhibits unrivalled high‐rate capacity retentions of &gt;550 371 mA h g −1 at 1 2 A , respectively, over 1000 cycles achieves excellent rate capability...