A new review of single-ion conducting polymer electrolytes in the light of ion transport mechanisms

With the depletion of fossil fuels and the demand for high-performance energy storage devices,solidstate lithium metal batteries have received widespread attention due to their high energy density and safety advantages.Among them,the earliest developed organic solid-state polymer electrolyte has a promising future due to its advantages such as good mechanical flexibility,but its poor ion transport performance dramatically limits its performance improvement.Therefore,single-ion conducting polymer electrolytes(SICPEs)with high lithium-ion transport number,capable of improving the concentration polarization and inhibiting the growth of lithium dendrites,have been proposed,which provide a new direction for the further development of high-performance organic polymer electrolytes.In view of this,lithium ions transport mechanisms and design principles in SICPEs are summarized and discussed in this paper.The modification principles currently used can be categorized into the following three types:enhancement of lithium salt anion-polymer interactions,weakening of lithium salt anion-cation interactions,and modulation of lithium ion-polymer interactions.In addition,the advances in single-ion conductors of conventional and novel polymer electrolytes are summarized,and several typical highperformance single-ion conductors are enumerated and analyzed in what way they improve ionic conductivity,lithium ions mobility,and the ability to inhibit lithium dendrites.Finally,the advantages and design methodology of SICPEs are summarized again and the future directions are outlined.

Elucidating Ion Transport Phenomena in Sulfide/Polymer Composite Electrolytes for Practical Solid-State Batteries

Despite the enormous interest in inorganic/polymer composite solid-state electrolytes(CSEs)for solid-state batteries(SSBs),the underlying ion transport phenomena in CSEs have not yet been elucidated.Here,we address this issue by formulating a mechanistic understanding of bi-percolating ion channels formation and ion conduction across inorganic-polymer electrolyte interfaces in CSEs.A model CSE is composed of argyrodite-type Li_6PS_5Cl(LPSCl)and gel polymer electrolyte(GPE,including Li~+-glyme complex as an ion-conducting medium).The percolation threshold of the LPSCl phase in the CSE strongly depends on the elasticity of the GPE phase.Additionally,manipulating the solvation/desolvation behavior of the Li~+-glyme complex in the GPE facilitates ion conduction across the LPSCl-GPE interface.The resulting scalable CSE(area=8×6(cm×cm),thickness~40μm)can be assembled with a high-mass-loading LiNi_(0.7)Co_(0.15)Mn_(0.15)O_(2)cathode(areal-mass-loading=39 mg cm~(-2))and a graphite anode(negative(N)/positive(P)capacity ratio=1.1)in order to fabricate an SSB full cell with bi-cell configuration.Under this constrained cell condition,the SSB full cell exhibits high volumetric energy density(480 Wh L_(cell)~(-1))and stable cyclability at 25℃,far exceeding the values reported by previous CSE-based SSBs.

Full-chain enhanced ion transport toward stable lithium metal anodes

The dendrite growth that results from the slow electrode process kinetics prevents the lithium(Li) metal anode from being used in practical applications. Here, full-chain enhanced ion transport for stabilizing Li metal anodes is proposed. Experimental and theoretical studies confirm that full-chain enhanced ion transport(electrocrystallization, mass transport in the electrolyte and diffusion in solid electrolyte interphase) under magnetoelectrochemistry contributes to a homogeneous, dense, and dendrite-free morphology. Specifically, the enhanced electrocrystallization behavior promotes the Li nucleation;the enhanced mass transport in the electrolyte alleviates the ion concentration gradient at the electrode surface, which helps to inhibit dendrite growth;and the enhanced diffusion in the solid electrolyte interphase further homogenizes the Li deposition behavior, obtaining regular and uniform Li particles.Consequently, the Li metal anode has exceptional cycling stability in both symmetric and full cells,and the pouch cell performs long cycles(170 cycles) in practice evaluation. This work advances fundamental knowledge of the magneto-dendrite effect and offers a new perspective on stabilizing metal anodes.

Molecular dynamics simulation of ion transportation through graphene nanochannels

The model of ion transportation through graphene nanochannels is established by the molecular dynamics simulation method. Statistics of the electric potential and charge distribution are made, respectively, on both sides of graphene nanopore with various diameters. Then, their changing relationship with respect to the nanopore diameter is determined. When applying a uniform electric field, polar water molecules are rearranged so that the corresponding relationship between the polarized degree of these molecules and the nanopore diameter can be created. Based on the theoretical model of ion transportation through nanochannels,the changing relationship between the concentration of anions/cations in nanochannels and bulk solution concentration is quantitatively analyzed. The results show that the increase of potential drop and charge accumulation, as well as a more obvious water polarization, will occur with the decrease of nanopore diameter. In addition, hydrogen ion concentration has a large proportion in nanochannels with a sodium chloride（NaCl） solution at a relative low concentration. As the NaCl concentration increases, the concentration appreciation of sodium ions tends to be far greater than the concentration drop of chloride ions. Therefore, sodium ion concentration makes more contribution to ionic conductance.

Effects of Hemp seed soft capsule on colonic ion transport in rats

AIM To investigate the effect of Hemp seed soft capsule(HSCC) on colonic ion transport and its related mechanisms in constipation rats.METHODS Sprague-Dawley male rats were randomly divided into three groups: normal group, constipation group and HSSC group. Rats in the constipation and HSSC groups were administrated loperamide 3 mg/kg per day orally for 12 d to induce the constipation model. Then, the HSSC group was given HSSC 0.126 g/kg per day by gavage for 7 d. The normal and constipation groups were treated with distilled water. After the treatment, the fecal wet weight and water content were measured. The basal short-circuit current(Isc) and resistance were measured by an Ussing Chamber. Besides the in vivo drug delivery experiment above, an in vitro drug application experiment was also conducted. The accumulative concentrations of HSSC(0.1 mg/m L, 0.5 mg/m L, 1.0 mg/m L, 2.5 mg/m L, 5.0 mg/m L, 10.0 mg/m L and 25.0 mg/m L) were added to the normal isolatedcolonic mucosa and the Isc was recorded. Further, after the application of either ion(Cl^-or HCO_3^-) substitution, ion channel-related inhibitor(N-phenylanthranilic acid, glybenclamide, 4,4-diisothiocyano-2,2-stilbenedisulfonic acid or bumetanide) or neural pathway inhibitor [tetrodotoxin(TTX), atropine, or hexamethonium], the Isc induced by HSSC was also measured. RESULTS In the constipation group, the fecal wet weight and the water content were decreased in comparison with the normal group(P < 0.01). After the treatment with HSSC, the fecal wet weight and the water content in the HSSC group were increased, compared with the constipation group(P < 0.01). In the constipation group, the basal Isc was decreased and resistance was increased, in comparison with the normal group(P < 0.01). After the treatment with HSSC, the basal Isc was increased(P < 0.05) and resistance was decreased(P < 0.01) in the HSSC group compared with the constipation group. In the in vitro experiment, beginning with the concentration of 1.0 mg/m L, differences in Isc were found between the experimental mucosa(with HSSC added) and control mucosa. The Isc of experimental mucosa was higher than that of control mucosa under the same concentration(1.0 mg/m L, P < 0.05; 2.5-25 mg/m L, P < 0.01). After the Cl^-or HCO_3^-removal and pretreated with different inhibitors(c AMPdependent and Ca^(2+)-dependent Cl^-channels, Na^+-K^+-2 Cl^-cotransporter(NKCC), Na^+-HCO_3^-cotransporter or Cl^-/HCO_3^-exchanger inhibitor), there were differences between experimental mucosa and control mucosa; the Isc of experimental mucosa was lower than that of control mucosa under the same concentration(P < 0.05). Meanwhile, after pretreatment with neural pathway inhibitor(TTX, atropine, or hexamethonium), there were no differences between experimental mucosa and control mucosa under the same concentration(P > 0.05).CONCLUSION HSSC ameliorates constipation by increasing colonic secretion, which is mediated via the coaction of c AMPdependent and Ca^(2+)-dependent Cl^-channels, NKCC, Na^+-HCO_3^-cotransporter or Cl^-/HCO_3^-exchanger.

TfR1 Extensively Regulates the Expression of Genes Associated with Ion Transport and Immunity

Transferrin receptor 1(TfR1),encoded by the TFRC gene,is the gatekeeper of cellular iron uptake for cells.A variety of molecular mechanisms are at work to tightly regulate TfR1 expression,and abnormal TfR1 expression has been associated with various diseases.In the current study,to determine the regulation pattern of TfR1,we cloned and overexpressed the human TFRC gene in HeLa cells.RNA-sequencing(RNA-seq)was used to analyze the global transcript levels in overexpressed(OE)and normal control(NC)samples.A total of 1669 differentially expressed genes(DEGs)were identified between OE and NC.Gene ontology(GO)analysis was carried out to explore the functions of the DEGs.It was found that multiple DEGs were associated with ion transport and immunity.Moreover,the regulatory network was constructed on basis of DEGs associated with ion transport and immunity,highlighting that TFRC was the node gene of the network.These results together suggested that precisely controlled TfR1 expression might be not only essential for iron homeostasis,but also globally important for cell physiology,including ion transport and immunity.

Lithium-ion transport in inorganic solid state electrolyte

An overview of ion transport in lithium-ion inorganic solid state electrolytes is presented, aimed at exploring and de signing better electrolyte materials. Ionic conductivity is one of the most important indices of the performance of inorganic solid state electrolytes. The general definition of solid state electrolytes is presented in terms of their role in a working cell （to convey ions while isolate electrons）, and the history of solid electrolyte development is briefly summarized. Ways of using the available theoretical models and experimental methods to characterize lithium-ion transport in solid state elec- trolytes are systematically introduced. Then the various factors that affect ionic conductivity are itemized, including mainly structural disorder, composite materials and interface effects between a solid electrolyte and an electrode. Finally, strategies for future material systems, for synthesis and characterization methods, and for theory and calculation are proposed, aiming to help accelerate the design and development of new solid electrolytes.

Investigation of Li-ion transport in Li7P3S11 and solid-state lithium batteries

The high Li-ion conductivity of the Li7P3S11 sulfide-based solid electrolyte makes it a promising candidate for all-solid-state lithium batteries. The Li-ion transport over electrode-electrolyte and electrolyteelectrolyte interfaces, vital for the performance of solid-state batteries, is investigated by impedance spectroscopy and solid-state NMR experiments. An all-solid-state Li-ion battery is assembled with the Li7P3S11 electrolyte, nano-Li2S cathode and Li-In foil anode, showing a relatively large initial discharge capacity of 1139.5 m Ah/g at a current density of 0.064 m A/cm^ 2 retaining 850.0 m Ah/g after 30 cycles. Electrochemical impedance spectroscopy suggests that the decrease in capacity over cycling is due to the increased interfacial resistance between the electrode and the electrolyte. 1D exchange ^7Li NMR quantifies the interfacial Li-ion transport between the uncycled electrode and the electrolyte, resulting in a diffusion coefficient of 1.70(3) ×10^-14cm^2/s at 333 K and an energy barrier of 0.132 e V for the Li-ion transport between Li2S cathode and Li7P3S11 electrolyte. This indicates that the barrier for Li-ion transport over the electrode-electrolyte interface is small. However, the small diffusion coefficient for Li-ion diffusion between the Li2S and the Li7P3S11 suggests that these contact interfaces between electrode and electrolyte are relatively scarce, challenging the performance of these solid-state batteries.

Luminal oxidants selectively modulate electrogenic ion transport in rat colon

AIM： To investigate the effects of luminal exposure to H2O2 and two related thiol oxidizing agents on basal and stimulated chloride secretion in native colon using electrophysiological and pharmacological approaches. METHODS： Unstripped rat distal colon segments were mounted in Ussing chambers. Potential difference, calculated resistance and short-circuit current across unstripped colon segments were monitored with a dual voltage/current clamp. Paracellular permeability was assessed by measuring the mucosa-to-serosa flux of a fluorescent probe （FITC）. RESULTS： Luminal exposure to hydrogen peroxide transitorily stimulated chloride secretion without altering barrier function. This stimulatory effect could be blocked by basolateral atropine but not indomethacin. The cysteine and methionine oxidizing compounds, phenylarsine oxide and chloramine T respectively, mimicked the effect of H2O2, except for a drop in transcolonic resistance after 30 min. In contrast to the observed stimulatory effect on basal secretion, cAMP-stimulated electrogenic ion transport was blunted by luminal H2O2. However, the Ca^2＋- activated response remained unchanged. CONCLUSION： H2O2 may be an important selective modulator of intestinal ion and water secretion in certain pathologic conditions such as inflammation or ischemiareperfusion by multiple mechanisms.

Semi-interpenetrating-network all-solid-state polymer electrolyte with liquid crystal constructing efficient ion transport channels for flexible solid lithium-metal batteries

The development of the solid-state polymer electrolytes (SPEs) for Li-ion batteries (LIBs) can effectively address the hidden safety issues of commercially used liquid electrolytes.Nevertheless,the unsatisfactory room temperature ion conductivity and inferior mechanical strength for linear PEO-based SPEs are still the immense obstacles impeding the further applications of SPEs for large-scale commercialization.Herein,we fabricate a series of semi-interpenetrating-network (semi-IPN) polymer electrolytes based on a novel liquid crystal (C6M LC) and poly(ethylene glycol) diglycidyl ether (PEGDE) via UV-irradiation at the first time.The LCs not only highly improve the mechanical properties of electrolyte membranes via the construction of network structure with PEGDE,but also create stable ion transport channels for ion conduction.As a result,a free-standing flexible SPE shows outstanding ionic conductivity(5.93×10^(-5) S cm^(-1) at 30℃),a very wide electrochemical stability window of 5.5 V,and excellent thermal stability at thermal decomposition temperatures above 360℃ as well as the capacity of suppressing lithium dendrite growth.Moreover,the LiFePO_(4)/Li battery assembled with the semi-IPN electrolyte membranes exhibits good cycle performance and admirable reversible specific capacity.This work highlights the obvious advantages of LCs applied to the electrolyte for the advanced solid lithium battery.

Ion Transport and Microstructure of Sandwich Cementitious Materials Exposed to Chloride Environment

Ion transport of sandwich cementitious materials（SCM） exposed to chloride environment was investigated by accelerated diffusion method and natural diffusion method. Pore structure and micromorphology of SCM were investigated by MIP and SEM-EDS. In comparison with the monolayer structural high performance concrete（HPC）, conductive charge for 6 hours, chloride diffusion coefficient, and apparent chloride diffusion coeffi cient of SCM were decreased by 30%-40%, two orders of magnitude and 40%-50%, respectively. Pore structure of ultra low ion permeability cementitious materials（ULIPCM） prepared for the facesheet is superior to that of HPC prepared for the core. As for porosity, the most probable pore radius, the content of pores with radius 50 nm and the surface area of pores, the order is ULIPCM

Ion Transport Measurements in a Multi-Dipole Argon Plasma by Broadband Laser Induced Fluorescence

Argon ion laser induced fluorescence measurements were carried out in a multipolar filament discharge with a broadband diode laser centered on 668 nm, which stimulated a transition from the metastable state in Ar（Ⅲ） 3d4F7/2 to 4p4D0 5/2. The intensity of the induced fluorescence at 442 nm was maximized by the optimization of the discharge parameters and the laser power. From the recovery of the background fluorescence after the laser was turned off, the ion diffusion coefficient was deduced and compared with the result inferred from the experiments of ion acoustic wave （IAW） damping.

Theoretical studies and molecular dynamics simulations on ion transport properties in nanochannels and nanopores

Control of ion transport and fluid flow through nanofluidic devices is of primary importance for energy storage and conversion, drug delivery and a wide range of biological processes. Recent development of nanotechnology, synthesis techniques, purification technologies, and experiment have led to rapid advances in simulation and modeling studies on ion transport properties. In this review, the applications of Poisson-Nernst-Plank （PNP） equations in analyzing transport properties are presented. The molecular dynamics （MD） studies of transport properties of ion and fluidic flow through nanofluidic devices are reported as well.

Regulating ion transport behaviors toward dendrite-free potassium metal batteries:recent advances and perspectives

With abundant potassium resources and high capacity,potassium metal batteries(PMBs)present a compelling option for the next generation of energy storage technology.However,PMBs suffer from an unstable anode interface caused by uncontrolled dendrite growth,which results in unsatisfactory cyclability and safety concerns.Extensive investigations suggest that significant progress has been made in enhancing the interfacial stability of PMBs.The various effective strategies for stabilizing interfaces can ultimately be attributed to the regulation of the sluggish ion transfer kinetics and irregular deposition,i.e.,the arrangement of ion transport behaviors at the interface.Rational modulation of ions transport rate and ions deposition directions makes it possible to obtain a dendrite-free and smooth deposition plane.Herein,the influencing factors and action mechanism of K^(+)interface transport behaviors are discussed to understand the nature of material design for constructing stable anode interfaces,including regulating the solvation and desolvation structures,accelerating K^(+)transport kinetics and controlling K^(+)deposition direction.In addition,the deficiencies and prospects of the research on electrolyte,separators and designed electrode involved in the manufacturing and testing and ion transport process of PMBs are discussed.This review is expected to provide some possible directions for constructing dendrite-free interfaces in advanced PMBs-related research and offer significant insights for prospective experimental research and commercial applications.

Ouabain-resistant phenomenon and changes of transmembrane ion transport in essential hypertensives with a family history of hypertension

Objective: To investigate the role of heredity in the ouabain-resistant phenomenon and the rela tionship between ouabain-resistance and transmembrane ion transport in essential hypertensives. Methods:A total of 52 essential hypertensives were investigated. of the patients, 23 were with a family history of hyper tension (FH+ group) and 29 were without (FH- group). Other 25 normotensives were employed to serve as the controls (control group). The percentage of 125I-digoxin binding to red blood cells (RBC-D% ) and plasma endogenous digoxin-like substance (EDLS) were measured with radioimmunoassay, 45Ca2+ influx in ATP-de pleted red cells by liquid scintillation counting. The rate constant of ouabain-sensitive sodium efflux (°Kos, h-1) was analyzed as half the increase in erythrocyte Na+ concentration during incubation with ouabain for 2 h. The maximal rate (Vmax) of red cell Na+/H+ exchange was determined as the influx promoted by an out ward H+ gradient then calculated. Results:The ouabain-sensitive Na+ efflux and RBC-D% were significantly lower but the levels of plasma EDLS and 45Ca2+ influx significantly higher in both FH+ and FH groups than in the control group. The plasma EDLS and ouabain-sensitive Na+ efflux were significantly higher but Ca2+ innux lower in FH+ group than in FH- group. Positive correlation was found between RBc-D% and ca2+ in flux in FH+ group. Conclusion: Ouabain-resistant phenomenon is related to the heredity of hypertension.The decrease in affinity of EDLS for membrane affects the transmembrane ion transport, which may partici pate in the pathogenesis of salt-sensitive hypertension.

Structural and Ion Transport Studies in (100-x) PVdF + xNH₄SCN Gel Electrolyte

In order to obtain highly conductive polymer gel electrolytes for electrochemical devices, Poly (vinylidene fluoride) (PVdF) based gel electrolytes namely (100–x)PVdF + xNH4SCN electrolyte system has been synthesized by solution cast technique and characterized by XRD, DSC, IR, SEM and electrical measurements. IR study of gel electrolytes shows interaction of PVdF matrix and dopant salt with prominence of α-phase. This result is also well supported by XRD and DSC studies. The electrolytes are electrochemically stable within ± 1.5 V. The optimum bulk electrical conductivity for 90PVdF + 10NH4SCN electrolyte has been found to be ~ 2.5 × 10–2 S●cm–1. Dielectric relaxation behavior shows low frequency dispersion and αc-related relaxation peak is observed in loss spectra. Polarization behavior of gel electrolyte shows ionic nature of charge transport (Tion. > 0.90). The temperature dependent conductivity shows VTF behavior.

Schrodinger-Langevin Equation and Ion Transport atNano Scale

Schrodinger-Langevin equation has been constructed for the ion-transport for K-ion channel. The stability of the solutions of this equation has been discussed under various physical situations. This will shed new light on the ion transport at nano-scale as well as the possibility of ion trapping and quantum information processing.

Sodium Ion Transport by Erythrocytes in hypertensives and Its Response to Antihypertensive Therapy

The transport of sodium ions by erythrocytes and the plasma level of endogenous digitalis-like compound (EDLC) were assessed in 59 patients with essential hypertension before and after theadminstration of nifedipine and prazosin. 20 normal subjects were studied similarly and served as con-trol. It was found that (1) EH patients had a pronounced defect of both the active and passive trans-port of sodium ions by the erythrocytes; (2) a higher plasma level of EDLC was detected in EH pa-tients as compared with that of the control, but the changes of EDLC and soudium pump were notparallel; (3) after the administration of nifedipine and prazosin, the function of sodium pump wasmarkedly improved and the plasma level of EDLC decreased. In addition, the relationship betweenthe transport of sodium ions by erythrocytes and the pathogenesis of EH, and the effects of anti-hypertensive agents were discussed.

Selective and asymmetric ion transport in covalent organic framework-based two-dimensional nanofluidic devices

Two-dimensional(2D)covalent organic framework(COF)mem-branes featuring well-aligned and programmable vertical nano-channels have emerged as a promising candidate for advanced nanofluidic devices and showcased vast potential in the fields of smart-gating,ion-separation,and energy-harvesting.However,the transverse interlayer nanochannels with a height of sub-nanometer-scale in 2D-COF membranes have scarcely been studied in com-parison.Here,we report the ion transport characteristics in 2D interlayer nanochannels of protonated CoF membranes.The dis-tinct surface-charge-governed ionic conductance in domination of electrolyte concentration below 1o-3 M as well as the exceptional anion/cation(Cl^(-)/K^(+))selectivity is revealed due to the pronounced charge and nano-confinement effects.Additionally,evident ion current rectification is witnessed when incorporating asymmetric geometry into the system,which is attributed to the dynamic process of ion enrichment and dissipation within the protonated nanochannels.This work offers immense prospects for 2D-COF membranes in the fields of biomimetic nanofluidic devices and cutting-edge electronic devices.

Ion heat transport in electron cyclotron resonance heated L-mode plasma on the T-10 tokamak

Anomalous ion heat transport is analyzed in the T-10 tokamak plasma heated with electron cyclotron resonance heating(ECRH) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECRH plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport is required. To study this effect two scans are presented: over the EC resonance position and over the ECRH power. The EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. The scan over the heating power is presented with on-axis and mixed ECRH regimes. Discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. The high ion heat transport regimes are distinguished by three parameters: the ratio Te/Ti, the normalized electron density gradient R/■, and the ion–ion collisionality νii~*. The combination of high Te/Ti, high νii~*, and R/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.