Abstract
Metal-ion batteries are key enablers in today’s transition from fossil fuels to renewable energy for a better planet with ingeniously designed materials being the technology driver. A ...central question remains how to wisely manipulate atoms to build attractive structural frameworks of better electrodes and electrolytes for the next generation of batteries. This review explains the underlying chemical principles and discusses progresses made in the rational design of electrodes/solid electrolytes by thoroughly exploiting the interplay between composition, crystal structure and electrochemical properties. We highlight the crucial role of advanced diffraction, imaging and spectroscopic characterization techniques coupled with solid state chemistry approaches for improving functionality of battery materials opening emergent directions for further studies.
This paper describes events of anomalously high energy transfer to a micro-object by fragments of nuclei generated in nuclear interactions in the environment on board a spacecraft in flight in ...low-Earth orbit. An algorithm has been developed that allows for the calculation of the absorbed energy from one or more fragments - products of nuclear interaction. With this algorithm the energy distributions for a spherical micro-volume in an aqueous medium were calculated. And the resulting absorbed energy spectra from nuclear fragments and from primary cosmic rays were compared. The role of nuclear interactions in events of large energy transfers in micro-objects in the field of primary cosmic radiation has been evaluated. The calculations performed in this study showed that the energy in a micro-volume from nuclear events can be several times higher compared to the energy imparted by primary space radiation.
The rapid progress in mass-market applications of metal-ion batteries intensifies the development of economically feasible electrode materials based on earth-abundant elements. Here, we report on a ...record-breaking titanium-based positive electrode material, KTiPO
F, exhibiting a superior electrode potential of 3.6 V in a potassium-ion cell, which is extraordinarily high for titanium redox transitions. We hypothesize that such an unexpectedly major boost of the electrode potential benefits from the synergy of the cumulative inductive effect of two anions and charge/vacancy ordering. Carbon-coated electrode materials display no capacity fading when cycled at 5C rate for 100 cycles, which coupled with extremely low energy barriers for potassium-ion migration of 0.2 eV anticipates high-power applications. Our contribution shows that the titanium redox activity traditionally considered as "reducing" can be upshifted to near-4V electrode potentials thus providing a playground to design sustainable and cost-effective titanium-containing positive electrode materials with promising electrochemical characteristics.
At present, there is concern about engineered nanoparticles in the environment, whereas natural nanoparticles (NPs) and their impact are often neglected. In our paper, we demonstrate the important ...role of nanoparticles of volcanic ash in transport of toxic elements on a global scale. A single volcanic eruption can eject millions of tons of ash. NPs of volcanic ash reach the upper troposphere and the stratosphere and may “travel” around the world for years affecting human health, environment, and even climate. So far, there is a gap in exposure assessment of volcanic ash NPs since their chemical composition remains largely unknown. Here we show for the first time that volcanic ash NPs can serve as an important carrier for potentially toxic elements. The concentrations of Ni, Zn, Cd, Ag, Sn, Se, Te, Hg, Tl, Pb, Bi in volcanic ash NPs (<100 nm) were found to be 10–500 times higher than total contents of these elements in bulk samples. This is valid for volcanoes from different regions of the world (Kamchatka, Far East of Russia and Andes, Chile). The work opens a new door into studies on biogeochemical impact of volcanic ash.
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•Nanoparticles (NPs) of volcanic ash were separated and quantitatively analyzed.•Samples of volcanic ash from different regions of the world were studied.•NPs are highly enriched by toxic elements as compared to bulk volcanic ash.•Dramatically high concentrations of Cd, Hg, Tl, Pb, Bi, Se, Te were found in NPs.•Volcanic ash NPs can serve as an important worldwide carrier for toxic elements.
The field of cosmic radiation at low-Earth orbit (LEO) has a complex composition. It always contains a component of secondary charged particles, formed by the products of nuclear interactions of the ...primary high-energy radiation with the nuclei of spacecraft’s shielding material, electronic components and biological matter on board. Generation of this secondary radiation can be observed in some track detectors in the form of “stars” formed by tracks—fragments with a common vertex. The energy absorbed by the medium in the region adjacent to the interaction vertex can reach abnormally high values because of its intersection by several particle fragments. In the present paper, a methodology is considered to calculate the energy imparted by such fragments to a spherical sensitive volume in an aqueous medium. The energy distributions for three fragment events were calculated for different positions of the vertex relative to the spherical volume. The obtained data were analyzed and were compared with the distribution for a uniform fluence of secondary particles. It was shown that as the fragmentation vertex approaches the boundary of the sensitive micro-volume, the probability of events with anomalously high energy transfers, higher than the energies from single fragments, increases. The method can be applied to calculate absorbed energy distributions from secondary radiation in media of different elemental composition than that used in the present work. In the future, it is of interest to apply the method for example to study the energy imparted from secondary fragments to a silicon medium, to quantify the number of single event upsets in electronic components.
We show how the nonlinear interaction effects ‘volume filling’ and ‘adhesion’ can be incorporated into the fractional subdiffusive transport of cells and individual organisms. To this end, we use ...microscopic random walk models with anomalous trapping and systematically derive generic non-Markovian and nonlinear governing equations for the mean concentrations of the subdiffusive cells or organisms. We uncover an interesting interaction between the nonlinearities and the non-Markovian nature of the transport. In the subdiffusive case, this interaction manifests itself in a nontrivial combination of nonlinear terms with fractional derivatives. In the long time limit, however, these equations simplify to a form without fractional operators. This provides an easy method for the study of aggregation phenomena. In particular, this enables us to show that volume filling can prevent “anomalous aggregation,” which occurs in subdiffusive systems with a spatially varying anomalous exponent.
•A microscopic stochastic model for subdiffusion with nonlinear interaction (volume filling and adhesion) is developed.•Macroscopic governing differential equations are derived which are consistent with the microscopic stochastic model.•Examples of stationary particle densities are computed which are subject to anomalous aggregation and nonlinear interaction.
An upgrade of the long baseline neutrino experiment T2K ND280 near detector is under development with the goal to reduce systematic uncertainties in the prediction of number of events at the ...Super-Kamiokande far detector. The upgrade program includes the design and construction of a new neutrino target, a novel highly granular fully active scintillator detector with 3D WLS fiber readout. The ∼2 tonnes 192 × 192 × 56 cm3 detector will be assembled from 2 × 106 plastic scintillator cubes of 1 × 1 × 1 cm3 size. Each cube is read out by three orthogonal Kuraray Y11 WLS fibers threaded through the detector. A detector prototype made of 125 cubes was assembled and tested in a charged particle beam at CERN in October 2017. This paper presents results from studies of light yield, time resolution and optical cross-talk between the cubes.
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