Single Ion Research Articles

Analysis of polyanion single ion conductor based on preparation of gel electrolyte for lithium ion battery

Abstract This study achieved efficient preparation of polyanionic single ion conductors by selecting appropriate raw materials and controlling preparation conditions. The results show that the window stability of electrolytic gel with a wide ionic electrochemical conductor is 2-4.5 V and 0.74 lithium ion migration. Lithium iron phosphate battery (LFP) is the positive electrode, lithium metal is the negative electrode, and PVDF-HFP Pampsli ion is the electrolyte. When lithium salt is not added, the rated power of the battery is 125 mah·g-1, and the current density is 2 C. The battery has a range of more than 500 times. In the current high-density 5 C situation, it has a specific capacity of 100 mAh·g-1 and a stable cycling ability of over 300 cycles, while maintaining nearly 100% stable Colomb efficiency.

A multi-electrode two-dimensional position sensitive diamond detector

In multi-electrode devices, charge pulses at all the electrodes are induced concurrently by the motion of the excess charge carriers generated by a single ion. This charge-sharing effect is such that the pulse amplitude at each sensitive electrode depends on the device geometry, its overall electrostatic configuration, and the charge transport properties of the detecting material. Therefore, the cross-analysis of the charge pulses induced at each electrode offers implicit information on the position of the ion impact. In this work, we investigate the two-dimensional position sensitivity of a diamond detector fabricated by deep ion beam lithography. By exploiting the ion beam induced charge technique, the device was exposed to a 2 MeV Li+ ion micro-beam to map the spatial dependence of the charge collection efficiency (CCE) on the nominal micro-beam scanning position. The combination of the CCE maps revealed a two-dimensional position sensitivity of the device with micrometric resolution at the center of the active region.

Wideband and low-spurious optical waveform generator for optically addressable quantum systems manipulation and control

Optical manipulation of quantum systems requires stable laser sources able to produce complex waveforms over a large frequency range. In the visible region, such waveforms can be generated using an acousto-optic modulator driven by an arbitrary waveform generator, but these suffer from a limited tuning range typically of a few tens of MHz. Visible-range electro-optic modulators are an alternative option offering a larger modulation bandwidth, however they have limited output power which drastically restricts the scalability of quantum applications. There is currently no architecture able to perform phase-stabilized waveforms over several GHz in the visible or near infrared region while providing sufficient optical power for quantum applications. Here we propose and develop a modulation and frequency conversion set-up able to deliver optical waveforms over a large frequency range, with a high spurious extinction ratio, scalable to the entire visible/near infrared region with high optical power. The optical waveforms are first generated at telecom wavelength and then converted to the emitter wavelength through a sum frequency generation process. By adapting the pump laser frequency, the optical waveforms can be tuned to interact with a broad range of optical quantum emitters or qubits such as alkali atoms, trapped ions, rare earth ions, or fluorescent defects in solid-state matrices. Using this architecture, we were able to detect and study a single erbium ion in a nanoparticle. We also generated high bandwidth signals at 606 nm, which would enable frequency multiplexing of on-demand read-out Pr3+:Y2SiO5 quantum memories.

Infrared Photodissociation Spectroscopy of Water-Tagged Ions with a Widely Tunable Quantum Cascade Laser for Planetary Science Applications.

This work presents a benchtop method for collecting the room temperature gas phase infrared (IR) action spectra of protonated amino acids and their isomers. The adopted setup uses a minimally modified commercial electrospray ionization linear ion trap mass spectrometer (ESI-LIT-MS) coupled to a broadband continuous wave (cw) quantum cascade laser (QCL) source. This approach leverages messenger assisted action spectroscopic techniques using water-tagged molecular ions with complex formation, irradiation, and subsequent analysis, all taking place within a single linear ion trap stage. This configuration thus circumvents the use of multiple mass selection and analysis stages, cryogenic buffer cells, and complex high-power laser systems typically called upon to execute these techniques. The benchtop action spectrometer is used to collect the 935-1600 cm-1 (6.2-10.7 μm) IR action spectrum of a collection of amino acids and a dipeptide with results cross referenced against literature examples obtained with a free electron laser source. Recorded IR spectra are used for the analysis of binary mixture samples composed of constitutional isomers α-alanine and β-alanine with ratios determined to ∼4% measurement uncertainty without the aid of a front-end separation stage. This turn-key QCL-based approach is a major step in showing the viability of tag-based action spectroscopic techniques for use in future in situ planetary science sensors and general analytical applications.

Kinetic theory of weakly ionized plasma and electrolyte mixtures including Onsager matrix and frequency dispersion effects

AbstractWe summarize the method of hydrodynamic approximation for weakly ionized plasmas developed with Klimontovich in 1962 and give a generalization to many—component systems using Onsagers matrix theory and including dispersion effects. We develop the conductivity theory of complex plasma and electrolyte mixtures based on the model of charged hard spheres with given non‐additive contact distances, including frequency‐dependent electric fields. These generalizations are made with the aim to allow applications to complex natural systems as atmospheric plasmas and seawater. Finally, we give as an example a numerical calculation of the single ion conductivities of a six‐component seawater model.

Hydrolysis of Nerve Agent Simulants Accelerated by Stimuli-Responsive Dinuclear Catalysts.

The ability to control the catalytic activity of enzymes in chemical transformations is essential for the design and development of artificial catalysts. Herein, we report the synthesis and characterization of functional ligands featuring two 1,4,7,10-tetraazacyclododecane units linked by an azobenzene group and their corresponding dinuclear Zn(II) complexes. We show that the configuration switching (E/Z) of the azobenzene spacer in the ligands and their dinuclear Zn(II) complexes is reversibly controlled by irradiation with UV and visible light. The Zn(II)-metal complexes are light-responsive catalysts for the hydrolytic cleavage of nerve agent simulants, i.e., p-nitrophenyl diphenyl phosphate and methyl paraoxon. The catalytic activity of the Z-isomers of the dinuclear Zn(II) complexes outperformed that of the E-counterparts. Moreover, combining the less active E-isomers with gold nanoparticles induced an enhancement in the hydrolysis rate of p-nitrophenyl diphenyl phosphate. Kinetic analysis has shown that the catalytic site appears to involve a single metal ion. We explain our results by considering the different desolvation effects occurring in the catalyst's configurations in the solution and the catalytic systems involving gold nanoparticles.

Ion solvation in atomic baths: From snowballs to polarons

AbstractSolvation, the result of the complicated interplay between solvent–solute and solvent–internal interactions, is one of the most important chemical processes. Consequently, a complete theoretical understanding of solvation seems like a heroic task. However, it is possible to elucidate fundamental solvation mechanisms by looking into simpler systems, such as ion solvation in atomic baths. In this work, we study ion solvation by calculating the ground state properties of a single ion in a neutral bath from the high‐density to the low‐density regimes, finding common ground for these two, in principle, disparate regimes. Our results indicate that a single 174Yb+ ion in a bath of 7Li atoms forms a coordination complex at high densities with a coordination number of 8, with strong electrostriction characteristic of the snowball effect. On the contrary, treating the atomic bath as a dilute quantum gas at low densities, we find that the ion‐atom interaction's short‐range plays a significant role in the physics of many‐body‐bound states and polarons. Furthermore, in this regime, we explore the role of an ion trap necessary to experimentally realize this system, which drastically affects the binding mechanism of the ion and atoms from a quantum gas. Therefore, our results give a novel insight into the universality of ion‐neutral systems in the ultracold regime and the possibilities of observing exotic many‐body effects.Keypoints A global study of ion solvation in atomic baths from the high‐ to the low‐density regimes. The ion–atom short‐range interaction is critical to understanding the presence of many‐body‐bound states and polarons. The ion‐trapping potential drastically impacts many‐body‐bound states and polaron formation.

Ion transport in composites of binary electrolyte and single ion conductor—A chronoamperometry study

Composite electrolytes for lithium batteries typically combine materials with very different mechanical properties and ionic transport mechanisms and the degree to which these two phases affect each other is not well understood. In this work we used numerical simulations and experiments to investigate the transport in composite electrolytes consisting of polyethylene oxide (PEO) with lithium bis-trifluoromethanesulfonimide (LiTFSI) and Li1.3Al0.3Ti1.7(PO4)3 (LATP) lithium ion conducting glass-ceramic particles. In particular we are interested in how the introduction of a single ion conductor (SIC) changes the salt concentration gradients in the polymer electrolyte (PE) under applied potential. To study this, we performed numerical simulations and chronoamperometry experiments in electrolytes with different arrangements of the SIC and PE phases, i.e. layers and particulate composites. The results show that the particulate composites have the highest concentration gradients and take the longest time to reach steady state current. The best arrangement appears to have a layer of SIC impenetrable to anions in the polymer phase within the electrolyte membrane.

Experimental and density-functional theory simulation studies on the surface of Mn/Pb-activated scheelite

The results of this study indicate that lead and manganese ions can serve as effective activators for the flotation of scheelite using benzohydroxamic acid (BHA) collectors, and even the addition of a small amount of lead ions can significantly improve the recovery rate of scheelite. The roughness of scheelite treated with binary activators and BHA is 8.19 nm and 2.1 nm higher than that the roughness values of scheelite treated with Mn(NO3)2 and Pb(NO3)2 alone, respectively. The adsorbed products are uniformly distributed on the scheelite surface, and the adsorption forms a “strip-like and dot-like” morphology. Lead ions are mainly adsorbed on mineral surfaces through Pb-O(H)-Ca, and manganese ions are mainly adsorbed in the form of Mn (II) species (i.e., Mn-O-Ca). In the presence of BHA, compared with scheelite treated with manganese and lead ions alone, scheelite treated with binary activators exhibits a more negative zeta potential on its surface, a higher contact angle of 89.30°, and a more pronounced infrared adsorption characteristic peak (C-N-O). DFT calculations confirm that lead ions and manganese ions are adsorbed on the surface of scheelite (112) in the forms of Pb-O-W, Mn-O-W, and Mn-O(H)-Ca. Moreover, the Pb-O(H)-Mn structure covers the surface atoms of scheelite, forming a layer of active substance on the surface of scheelite, and the structure is more stable than in the case of single ion activation, according to the BHA adsorption calculations.

Effects of single and simultaneous Fe, He ions irradiations on CoCrFeMnNi high entropy alloy

Simultaneous irradiation was performed on CoCrFeMnNi high entropy alloy (HEA) at room temperature using Fe ions and He ions, and single Fe ions irradiation and single He ions irradiation were used as comparisons. The synergistic effect of the two ions on irradiation-induced defects such as dislocation loops and He bubbles, as well as the effect of irradiation damage on the nano-hardness were investigated. As the irradiation dose increased, a distribution with small and dense dislocation loops was first formed in CoCrFeMnNi HEA, and then these dislocation loops merged and grew. However, compared to pure metal, CoCrFeMnNi HEA entered the dislocation loop merging stage at a higher threshold dose due to its higher defect recombination capacity and higher critical stress of initial dislocation motion. Compared with the single Fe ions irradiation, the addition of He in the simultaneous irradiation accelerated the merging and growth of dislocation loops and decreased the density of dislocation loops. At the same He dose, simultaneous irradiation produced a higher vacancy concentration than single He ions irradiation, which increased He mobility, leading to wider He bubble layer and larger He bubble size. CoCrFeMnNi HEA hardened after irradiation with all three parameters in the order of single He ions irradiation > single Fe ions irradiation > simultaneous Fe+He ions irradiation. This study provided a deeper understanding of the irradiation damage mechanism of HEA in complex irradiation environment.

Noise characterization of an ultra-stable laser for optical clocks.

We report on the development and performance evaluation of an ultra-stable laser for an 27Al+ optical clock. After a series of noise suppressions, especially the vibrational and temperature fluctuation noise, the 30cm long cavity stabilized laser obtains a frequency instability of 1.3 × 10-16 @1s. This result is predicted by noise summation and confirmed by the three-cornered hat method. The 27Al+ optical clock transition is also used to characterize the laser frequency noise, and consistent results are yielded. This is the first reported instance of using single ion optical clocks to measure the frequency noise of ultra-stable lasers, as far as we know. With the implementation of the ultra-stable clock laser, an ultra-narrow linewidth clock transition of 2.8Hz is obtained.

Ultraviolet-B and Near-Infrared Dual-Band Luminescence in Bi3+/Bi2+ Codoped Persistent Phosphor for Optical Storage Application.

Discovering multifunctional luminescent materials to meet the demands of modern spectroscopy is of great significance. However, it is a standing challenge to enable multiple luminescence properties in a single material system via single metal ion doping. Here, we report the inherently Bi3+/Bi2+ codoped Ca3Ga2Ge3O12 persistent phosphor where Bi3+ is in situ reduced to Bi2+. This phosphor can act as an efficient multimodal luminescence material, which simultaneously exhibits long-lasting (>12 h) ultraviolet-B (UVB) and near-infrared (NIR) dual-band persistent luminescence after irradiation by 254 nm ultraviolet (UV) light. UVB and NIR afterglow are ascribed to the distinct Bi3+ and Bi2+ emitters, respectively, proven by comprehensive spectroscopic investigations including X-ray absorption near-edge structure spectra and X-ray photoelectron spectroscopy. Besides, this phosphor also exhibits exceptional photochromic features, accompanied by a rapid body color transformation from white to brown in response to 254 nm UV light within 60 s and excellent recovery capacity upon thermal or blue/white light stimulation. The combination of UVB persistent luminescence of Bi3+ and NIR afterglow of Bi2+ coupled with reversible white-to-brown photochromism phenomenon offers one type of promising multifunctional luminescence material, showing potential to be used for optical storage and anti-counterfeiting applications.

Innovative direct introduction-ion mobility-mass spectrometry (DI-IM-MS) approach for fast and robust isomer-specific quantification in a complex matrix: Application to 2'-fucosyllactose (2'-FL) in breast milk.

Identification and specific quantification of isomers in a complex biological matrix by mass spectrometry alone is not an easy task due to their identical chemical formula and therefore their same mass-to-charge ratio (m/z). Here, the potential of direct introduction combined with ion mobility-mass spectrometry (DI-IM-MS) for rapid quantification of isomers as human milk oligosaccharides (HMOs) was investigated. Differences in HMO profiles between various analyzed breast milk samples were highlighted using the single ion mobility monitoring (SIM2) acquisition for high ion mobility resolution detection. Furthermore, the Se+ (secretor) or Se- (non-secretor) phenotype could be assigned to breast milk samples studied based on their HMO contents, especially on the response of 2'-fucosyllactose (2'-FL) and lacto-N-fucopentaose I (LNFP I). The possibility of quantifying a specific isomer in breast milk by DI-IM-MS was also investigated. The standard addition method allowed the determination of the 2'-FL despite the presence of other oligosaccharides, including 3-fucosyllactose (3-FL) isomer in breast milk. This proof-of-concept study demonstrated the high potential of such an approach for the rapid and convenient quantification of isomers in complex mixtures.

Simulation and analysis of inverse-mode operation of single event transient mechanisms on NPN-SiGe HBT

This work presents the characteristics of the single event transient (SET) induced by a single heavy ion in the inverse mode NPN-SiGe HBT simulated with the Silvaco TCAD toolkit. The designed SiGe HBT technology structure was built on the DevEdit simulator and simulated on Deckbuild using device and radiation effect simulations. The characteristics of device SET distribution, including transient pulse current, corresponding collection charge, pulse current peak, and full width at half maximum (FWHM) levels, etc, were simulated and compared as they changed with heavy ion LETs (0.2 pC μm−1 ∼ 1.0 pC μm−1), striking angles (30° ∼ 120°), and device emitter bias voltage settings (0.6 V ∼ 1.8 V). Meanwhile, the electrostatic potential distribution was found to be impacted by the heavy ion SET at the initial time moment when the heavy ion began to strike the surface of the device. The mechanisms for SET variation and its influence on the device potential under different conditions were primarily analyzed and discussed.

Superior radiation resistance of ODS-RAFM steels revealed by Positron annihilation spectroscopy study

Oxide-dispersion-strengthened (ODS) reduced-activation ferritic/martensitic (RAFM) steels are considered as most promising structural materials for fusion reactors and other advanced nuclear systems due to its excellent irradiation resistance under high dose irradiations. However, the extreme complex synergistic effect between transmuted helium/hydrogen and displacement damage which most seriously affects the structure and mechanical properties of ODS-RAFM steels is very difficult to understand, especially the role of hydrogen still remains unclear. Taking advantage of very sensitive to small vacancy clusters of Positron annihilation spectroscopy (PAS) method, we conducted irradiation defect study on ODS-RAFM, RAFM and its corresponding model alloy Fe–9Cr and α-Fe to investigate their anti-swelling properties at the early stage of irradiation with hydrogen-helium synergism and the mechanism. Three distinct irradiation schemes including (1) single Fe ion beam, (2) simultaneous Fe and He (named Fe + He) ion beam, (3) subsequent H ion injection after Fe + He (named Fe + He/H) ion beam irradiation were performed. Hydrogen-helium synergistic effects on vacancy evolution within these steels were explored combining the first-principles calculation. The implantation of He was observed to significantly increase defect concentration among all four steels, while H exhibited interestingly complexity on affecting the evolution of helium bubbles. The H post-injection increased defect concentration obviously in the materials with abundant sinks, but improved poorly in ones with rare sinks. Through the systematic study of the interactions between H, He, and vacancies, it was revealed that even at the early irradiation stage, ODS-RAFM steels has already exhibited excellent irradiation resistance compared to other alloys across three irradiation schemes.

Double-Layer Distribution of Hydronium and Hydroxide Ions in the Air-Water Interface.

The acid-base nature of the aqueous interface has long been controversial. Most macroscopic experiments suggest that the air-water interface is basic based on the detection of negative charges at the interface that indicates the enrichment of hydroxides (OH-), whereas microscopic studies mostly support the acidic air-water interface with the observation of hydronium (H3O+) accumulation in the top layer of the interface. It is crucial to clarify the interfacial preference of OH- and H3O+ ions for rationalizing the debate. In this work, we perform deep potential molecular dynamics simulations to investigate the preferential distribution of OH- and H3O+ ions at the aqueous interfaces. The neural network potential energy surface is trained based on density functional theory calculations with the SCAN functional, which can accurately describe the diffusion of these two ions both in the interface and in the bulk water. In contrast to the previously reported single ion enrichment, we show that both OH- and H3O+ surprisingly prefer to accumulate in interfaces but at different interfacial depths, rendering a double-layer ionic distribution within ∼1 nm near the Gibbs dividing surface. The H3O+ preferentially resides in the topmost layer of the interface, but the OH-, which is enriched in the deeper interfacial layer, has a higher equilibrium concentration due to the more negative free energy of interfacial stabilization [-0.90 (OH-) vs -0.56 (H3O+) kcal/mol]. The present finding of the ionic double-layer distribution may qualitatively offer a self-consistent explanation for the long-term controversy about the acid-base nature of the air-water interface.

Investigating sulfide-based all solid-state cells performance through P2D modelling

All solid-state batteries, combining metallic lithium with a solid-state electrolyte, are now considered as a very promising answer to the growing need for higher energy density in safer batteries. While research interests are quickly raising on this topic, the number of experiments to perform in order to find the best combination of active material and solid electrolyte composition could be infinite. Therefore, an easy and low computational-cost model forecasting all solid-state cells performance could accelerate the optimization and lower the number of experiments, reaching more rapidly an up scalable solution.In this work, an innovative electrochemical model for a metallic lithium – argyrodite Li6PS5Cl – NMC622 cell is developed. In particular, two important aspects, characterizing this new battery generation, are implemented inside a P2D model.The first aspect is the implementation of a solid-state electrolyte, in substitution to liquid electrolyte, which means using the single ion conducting electrolyte theory, according to which Ohm's law is the only equation to be solved in the electrolyte domain. This reduces the number of parameters characterizing the electrolyte from three, for the liquid electrolyte (ionic conductivity, transference number, and mean molar activity coefficient), to only one, for the solid electrolyte (ionic conductivity). The second aspect regards the anode side, lithium metal is chosen, in substitution to graphite, and this implies a different treatment from an electrochemical point of view, which is to consider the anode as a boundary condition instead of a porous electrode. Such drastic simplification of the P2D model allows, after careful calibration and validation based on experimental data, to obtain reliable charge/discharge profiles at C/10 and C/5 for lithium – argyrodite Li6PS5Cl – NMC622 cells.

Three coordinated first row-transition metal complexes, [M{N(SiMe3)2}3]−1/0: Structure, bonding, and magnetic properties

Structure, bonding, and magnetic properties of [M{N(SiMe3)2}3]−1/0 (M = first row-transition metal, Sc-Cu in + 2/+3 oxidation state) complexes are studied. The atoms in molecules (AIM) analysis shows that non-covalent interactions between the methyl hydrogens are prevalent. Energy decomposition analysis coupled with natural orbital for chemical valence (EDA-NOCV) analysis shows that the ligand is bonded to the metal ions through σ and π bonding. In addition, the reasonable contribution from the dispersion interaction supports van der Waals' type of interaction. The highest value of magnetic anisotropy (D) is calculated in the NiII complex with a value of −382.945 (−234.145) cm−1 at the CASSCF (NEVPT2) level of theory. It is significantly higher than the previously reported values of −14.644 (−15.631) and −63.691 (−64.000) cm−1 in similar CrII and MnIII complexes, respectively. Ab Initio Ligand Field Theory (AILFT) is utilized to calculate the splitting of the d-orbitals in all the metal complexes. In the NiII complexes, the blocking barrier (Ueff) is found to be 127 cm−1. Thus, it has a high potential to be utilized as a single ion magnet (SIM).

Ag+-Mediated Folding of Long Polyguanine Strands to Double and Quadruple Helixes.

Metal-mediated base pairing of DNA has been a topic of extensive research spanning over more than four decades. Precise positioning of a single metal ion by predetermining the DNA sequence, as well as improved conductivity offered by the ions, make these structures interesting candidates in the context of using DNA in nanotechnology. Here, we report the formation and characterization of conjugates of long (kilo bases) homoguanine DNA strands with silver ions. We demonstrate using atomic force microscopy (AFM) and scanning tunneling microscope (STM) that binding of silver ions leads to folding of homoguanine DNA strands in a "hairpin" fashion to yield double-helical, left-handed molecules composed of G-G base pairs each stabilized by a silver ion. Further folding of the DNA-silver conjugate yields linear molecules in which the two halves of the double helix are twisted one against the other in a right-handed fashion. Quantum mechanical calculations on smaller molecular models support the helical twist directions obtained by the high resolution STM analysis. These long guanine-based nanostructures bearing a chain of silver ions have not been synthesized and studied before and are likely to possess conductive properties that will make them attractive candidates for nanoelectronics.

Different solvents accompanied by different structures: Catalyst-free one step construction of highly branched polythioureas and its properties

In this study, tris(2-aminoethyl)amine and carbon disulfide were used as raw materials for the construction of highly branched polythioureas. Firstly, a highly branched polythiourea adsorbent was synthesized through a heating condensation reaction using N, N-dimethylformamide (DMF) as solvent without any catalyst. Interestingly, this study also revealed that a highly branched polythiourea resin was successfully synthesized without any catalyst when water was used as the solvent. Through nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), gel chromatography column (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and other means to characterize the comprehensive properties of the polymer. Then, mercury ions were used as the adsorption model. The effects of adsorbent dosing, adsorption time, and different pH on the adsorption of mercury ions (Hg2+) were investigated by intermittent adsorption experiments. The adsorption kinetics, isotherm model, sensitivity test of mercury extraction, single metal ion test, and the adsorption capacity of the adsorbent for nine metal ions were studied. In addition, bond strength tests were utilized to explore the adhesive properties of the prepared aqueous phase highly branched polythioureas. The results show that in the adsorption performance test, when the dosage of highly branched polythiourea adsorbent is 10 mg, the pH is acidic or neutral, and the adsorption time is 60 min, the adsorption efficiency of P-DMF for Hg2+ is as high as 99.99 %. The adsorption follows the Langmuir isotherm model and fits well with the pseudo-second-order kinetic model. In addition, P-DMF has a certain selectivity for Hg2+, and the adsorption efficiency is positively correlated with the mercury ion concentration. When Hg2+ is 100 mg/L, the adsorption efficiency reaches 99.98 %. In the bond strength test, the dry shear strength of the plywood reached 1.6 MPa, and the strength after soaking in hot water and boiling water for 3 h was 1.5 MPa and 1.4 MPa respectively, exceeding the requirements of GB/T9846-2015 for type II plywood (≥0.7 MPa).