Li+ effect on the cell wall of the yeast Saccharomyces cerevisiae as probed by FT-IR spectroscopy

The effect of Li⁺ ions as a transformation inducing agent on the yeast cell wall has been studied. Two Saccharomyces cerevisiae strains, p63-DC5 with a native cell wall, and strain XCY42-30D(mnn1) which contains structural changes in the mannan-protein complex, were used. Fourier transform infrared (FT-IR) spectroscopy has been used for the characterization of the yeast strains and for determination of the effect of lithium cations on the cell wall. A comparison of the carbohydrate absorption band positions in the 970–1185 cm^?1 range, of Na⁺ and Li⁺ treated yeast cells has been estimated. Absorption band positions of the cell wall carbohydrates of p63-DC5 were not influenced by the studied ions. On the contrary, the treatment of XCY42-30D(mnn1) cells with Li⁺ ions shifted glucan band positions, implying that the cell wall structure of strain XCY42-30D(mnn1) is more sensitive to Li⁺ ion treatment.     

Real-time measurements of quartz erosion in experiments modeling heat loads on divertor plates during disruption in tokamaks

Time-resolved measurements of quartz erosion are carried out to determine the density of the energy flux incident onto the sample surface. These data are needed to create a reliable code describing the interaction of a thermonuclear plasma with a solid surface. Experiments were performed in the 2MK-200 facilityunder the program of modeling heat loads on divertor plates during disruptions in tokamaks. A 10-mm-thick plate of fused quartz was exposed to a high-temperature deuterium-plasma stream with the temperature T _i +T _e ≤1 keV, density (5–10)×10¹⁵ cm⁻³ β=0.25, energy density up to 200 J/cm², and power density ∼10 MW/cm². It is shown that the quartz erosion begins almost immediately after the stream reaches the surface. The eroded material shields the quartz surface from further destruction. Under the given experimental conditions, the integral shielding factor (the ratio of the stream energy to the energy reaching the surface) was rather high (about seventeen). As a result, at a stream energy density of ∼150 J/cm², the total erosion depth was about 0.75 μm over 35 μs. Based on the measured time dependence of the erosion depth and the reference data on the thermal conductivity of the fused quartz, the power density incident onto the quartz sample was numerically calculated. __________ Translated from Fizika Plazmy, Vol. 27, No. 3, 2001, pp. 243–250. Original Russian Text Copyright ? 2001 by Arkhipov, Bakhtin, Vasenin, Zhitlukhin, Safronov, Toporkov.     

3D Vertically Aligned Li Metal Anodes with Ultrahigh Cycling Currents and Capacities of 10 mA cm−2/20 mAh cm−2 Realized by Selective Nucleation within Microchannel Walls

Although metallic lithium is regarded as the “Holy Grail” for next‐generation rechargeable batteries due to its high theoretical capacity and low overpotential, the uncontrollable Li dendrite growth, especially under high current densities and deep plating/striping, has inhibited its practical application. Herein, a 3D‐printed, vertically aligned Li anode (3DP‐VALi) is shown to efficiently guide Li deposition via a “nucleation within microchannel walls” process, enabling a high‐performance, dendrite‐free Li anode. Moreover, the microchannels within the microwalls are beneficial for promoting fast Li⁺ diffusion, supplying large space for the accommodation of Li during the plating/stripping process. The high‐surface‐area 3D anode design enables high operating current densities and high areal capacities. As a result, the Li–Li symmetric cells using 3DP‐VALi demonstrate excellent electrochemical performances as high as 10 mA cm^?2/10 mAh cm^?2 for 1500 h and 5 mA cm^?2/20 mAh cm^?2 for 400 h, respectively. Additionally, the Li–S and Li–LiFePO₄ cells using 3DP‐VALi anodes present excellent cycling stability up to 250 and 800 cycles at a rate of 1 C, respectively. It is believed that these new findings could open a new window for dendrite‐free metal anode design and pave the way toward energy storage devices with high energy/power density.     

Theoretical Investigation of 2D Layered Materials as Protective Films for Lithium and Sodium Metal Anodes

Rechargeable batteries based on lithium (sodium) metal anodes have been attracting increasing attention due to their high capacity and energy density, but the implementation of lithium (sodium) metal anode still faces many challenges, such as low Coulombic efficiency and dendrites growth. Layered materials have been used experimentally as protective films (PFs) to address these issues. In this work, the authors explore using first‐principles computations the key factors that determine the properties and feasibility of various 2D layered PFs, including the defect pattern, crystalline structure, bond length, and metal proximity effect, and perform the simulations on both aspects of Li⁺ (Na⁺) ion diffusion property and mechanical stability. It is found that the introduction of defect, the increase in bond length, and the proximity effect by metal can accelerate the transfer of Li⁺ (Na⁺) ion and improve the ionic conductivity, but all of them make negative influences on the stiffness of materials against the suppression of dendrite growth and weaken both critical strains and critical stress. The results provide new insight into the interaction mechanism between Li⁺ (Na⁺) ions and PF materials at the atomic level and shed light onto exploring a variety of layered PF materials in metal anode battery systems.     

Dielectric saturation of the aqueous boundary layers adjacent to charged bilayer membranes

Summary The surface charge density resulting from the adsorption of hydrophobic anions of dipicrylamine onto dioleyl-lecithin bilayer membranes has been measured directly using a high field pulse method. The surface charge density increases linearly with adsorbate concentration in the water until electrostatic repulsion of impinging hydrophobic ions by those already adsorbed becomes appreciable. Then Gouy-Chapman theory predicts that surface charge density will increase sublinearly, with the power [z ⁺/(z ⁺+2)] of the adsorbate concentration, wherez ⁺ is the cation valence of the indifferent electrolyte screening the negatively charged membrane surface. The predicted 1/3 and 1/2 power laws for univalent and divalent cations, respectively, have been observed in these experiments using Na⁺, Mg⁺⁺, and Ba⁺⁺ ions. Gouy-Chapman theory predicts further that the change from linear to sublinear dependence takes place at a surface charge density governed by the static dielectric constant of water and the concentration of indifferent electrolyte. Quantitative agreement with experiment is obtained at electrolyte concentrations of 10^–4 m and 10^–3 m, but can be maintained at higher concentrations only if the aqueous dielectric constant is decreased. A transition field model is proposed in which the Gouy-Chapman theory is modified to take account of dielectric saturation of water in the intense electric fields adjacent to charged membrane surfaces.     

An Anion‐Tuned Solid Electrolyte Interphase with Fast Ion Transfer Kinetics for Stable Lithium Anodes

The spatial distribution and transport characteristics of lithium ions (Li⁺) in the electrochemical interface region of a lithium anode in a lithium ion battery directly determine Li⁺ deposition behavior. The regulation of the Li⁺ solvation sheath on the solid electrolyte interphase (SEI) by electrolyte chemistry is key but challenging. Here, 1 m lithium trifluoroacetate (LiTFA) is induced to the electrolyte to regulate the Li⁺ solvation sheath, which significantly suppresses Li dendrite formation and enables a high Coulombic efficiency of 98.8% over 500 cycles. With its strong coordination between the carbonyl groups (C?O) and Li⁺, TFA^? modulates the environment of the Li⁺ solvation sheath and facilitates fast desolvation kinetics. In addition, due to relatively smaller lowest unoccupied molecular orbital energy than solvents, TFA^? has a preferential reduction to produce a stable SEI with uniform distribution of LiF and Li₂O. Such stable SEI effectively reduces the energy barrier for Li⁺ diffusion, contributing to low nucleation overpotential, fast ion transfer kinetics, and uniform Li⁺ deposition with high cycling stability. This work provides an alternative insight into the design of interface chemistry in terms of regulating anions in the Li⁺ solvation sheath. It is anticipated that this anion‐tuned strategy will pave the way to construct stable SEIs for other battery systems.     

Co–B Nanoflakes as Multifunctional Bridges in ZnCo2O4 Micro‐/Nanospheres for Superior Lithium Storage with Boosted Kinetics and Stability

Transition metal oxides hold great promise as high‐energy anodes in next‐generation lithium‐ion batteries. However, owing to the inherent limitations of low electronic/ionic conductivities and dramatic volume change during charge/discharge, it is still challenging to fabricate practically viable compacted and thick TMO anodes with satisfactory electrochemical performance. Herein, with mesoporous cobalt–boride nanoflakes serving as multifunctional bridges in ZnCo₂O₄ micro‐/nanospheres, a compacted ZnCo₂O₄/Co–B hybrid structure is constructed. Co–B nanoflakes not only bridge ZnCo₂O₄ nanoparticles and function as anchors for ZnCo₂O₄ micro‐/nanospheres to suppress the severe volume fluctuation, they also work as effective electron conduction bridges to promote fast electron transportation. More importantly, they serve as Li⁺ transfer bridges to provide significantly boosted Li⁺ diffusivity, evidenced from both experimental kinetics analysis and density functional theory calculations. The mesopores within Co–B nanoflakes help overcome the large Li⁺ diffusion barriers across 2D interfaces. As a result, the ZnCo₂O₄/Co–B electrode delivers high gravimetric/volumetric/areal capacities of 995 mAh g^?1/1450 mAh cm^?3/5.10 mAh cm^?2, respectively, with robust rate capability and long‐term cyclability. The distinct interfacial design strategy provides a new direction for designing compacted conversion‐type anodes with superior lithium storage kinetics and stability for practical applications.     

Muscle: A Three Phase System : The partition of divalent ions across the membrane

The partition of sulfate, Ca⁺⁺, and Mg⁺⁺ across the membrane of the sartorius muscle has been studied, and the effect of various concentrations of these ions in the Ringer solution on the cellular level of Na⁺, K⁺, and Cl^- has been determined. The level of the three divalent ions in toad plasma and muscle in vivo has been assayed. Muscle was found to contain an almost undetectable amount of inorganic sulfate. Increases in the external level of these ions brought about increases in intracellular content, calculated from the found extracellular space as determined with radioiodinated serum albumin or inulin. Less of the cell water is available to sulfate than to Cl^-, and the Mg⁺⁺ space is less than the Na⁺ space. An amount of muscle water similar to that found for Li⁺ and I^- appears to be available to these divalent ions. Sulfate efflux from the cell was extremely rapid, and it was not found possible to differentiate kinetically between intra- and extracellular material. These results are consistent with the theory of a three phase system, assuming the muscle to consist of an extracellular phase and two intracellular phases. Mg⁺⁺ and Ca⁺⁺ are adsorbed onto the ordered phase, and increments in cellular content found on raising the external level are assumed to occur in the free intracellular phase.     

Metal Sulfide‐Decorated Carbon Sponge as a Highly Efficient Electrocatalyst and Absorbant for Polysulfide in High‐Loading Li2S Batteries

Owing to its high theoretical specific capacity (1166 mA h g^?1) and particularly its advantage to be paired with a lithium‐metal‐free anode, lithium sulfide (Li₂S) is regarded as a much safer cathode for next‐generation advanced lithium–sulfur (Li–S) batteries. However, the low conductivity of Li₂S and particularly the severe “polysulfide shuttle” of lithium polysulfide (LiPS) dramatically hinder their practical application in Li–S batteries. To address such issues, herein a bifuctional 3D metal sulfide‐decorated carbon sponge (3DTSC), which is constructed by 1D carbon nanowires cross‐linked with 2D graphene nanosheets with high conductivity and polar 0D metal sulfide nanodots with efficient electrocatalytic activity and strong chemical adsorption capability for LiPSs, is presented. Benefiting from the well‐designed multiscale, multidimensional 3D porous nanoarchitecture with high conductivity, and efficient electrocatalytic and absorption ability, the 3DTSC significantly mitigates LiPS shuttle, improves the utilization of Li₂S, and facilitates the transport of electrons and ions. As a result, even with a high Li₂S loading of 8 mg cm^?2, the freestanding 3DTSC‐Li₂S cathode without a polymer binder and metallic current collector delivers outstanding electrochemical performance with a high areal capacity of 8.44 mA h cm^?2.     

Bioelectric effects of ions microinjected into the giant axon of Loligo

1. A technique is described for recording the bioelectric activity of the squid giant axon during and following alteration of the internal axonal composition with respect to ions or other substances. 2. Experimental evidence indicates that the technique as described is capable of measuring changes in local bioelectric activity with an accuracy of 10 to 15 per cent or higher. 3. Alterations of the internal K⁺ or Cl^- concentrations do not cause the change in resting potential expected on the basis of a Donnan mechanism. 4. The general effect of microinjection of K⁺ Rb⁺, Na⁺, Li⁺, Ba⁺⁺, Ca⁺⁺, Mg⁺⁺, or Sr⁺⁺ is to cause decrease in spike amplitude, followed by propagation block. 5. The resting potential decreases when the amplitude of the spike becomes low and block is incipient. 6. The decrease in resting potential and spike amplitude may be confined to the immediate vicinity of the injection. 7. At block, the resting potential decreases up to 50 per cent, but injection of small quantities of divalent cations may cause much larger localized depolarization. 8. The blocking effectiveness of K⁺, Na⁺, and Ca⁺⁺ expressed as reciprocals of the relative amounts needed to cause block is approximately 1:5:100. Rb⁺ has the same low effectiveness as does K⁺. Li⁺ resembles Na⁺. Ba⁺⁺ and Mg⁺⁺ are approximately as effective as Ca⁺⁺. 9. Microinjection of Na⁺ may cause marked prolongation of the spike at the injection site as well as decrease in its amplitude. 10. The anions used (Cl^-, HCO₃^-, NO₃^-, SO₄^-, aspartate, and glutamate) do not seem to exert specific effects. 11. A tentative explanation is offered for the insensitivity of the resting potential to changes in the axonal ionic composition. 12. New data are presented on the range of variation, in a large sample, of the magnitude of the resting potential and spike amplitude.     

Ca++ fluxes in resealed synaptic plasma membrane vesicles

The effect of the monovalent cations Na⁺, Li⁺, and K⁺ on Ca⁺⁺ fluxes has been determined in resealed synaptic plasma membrane vesicle preparations from rat brain. Freshly isolated synaptic membranes, as well as synaptic membranes which were frozen (?80°C), rapidly thawed, and passively loaded with K₂/succinate and ⁴⁵CaCl₂, rapidly released approximately 60% of the intravesicular Ca⁺⁺ when exposed to NaCl or to the Ca⁺⁺ ionophore A 23187. Incubation of these vesicles with LiCl caused a lesser release of Ca⁺⁺. The EC₅₀ for Na⁺ activation of Ca⁺⁺ efflux from the vesicles was approximately 6.6mM. exposure of the Ca⁺⁺-loaded vesicles to 150 mM KCl produced a very rapid (?1 sec) loss of Ca⁺⁺ from the vesicles, but the Na⁺-induced efflux could still be detected above this K⁺ - sensitive effect. Vesicles pre-loaded with NaCl (150 mM) exhibited rapid ⁴⁵Ca uptake with an estimated EC₅₀ for Ca⁺⁺ of 7–10 μM. This Ca⁺⁺ uptake was blocked by dissipation of the Na⁺ gradient. These observations are suggestive of the preservation in these purified frozen synaptic membrane preparations of the basic properties of the Na⁺Ca⁺⁺ exchange process and of a K⁺ - sensitive Ca⁺⁺ flux across the membranes.     

Toward a Four‐Electron Redox Quinone Polymer for High Capacity Lithium Ion Storage

Despite recent advances, current polymeric organic cathode materials have failed to incorporate a high degree of lithium storage in a small molecular framework, resulting in low capacities relative to monomers. This report discloses the development of a lithium salt polymer of dihydroxyanthraquinone (LiDHAQS) capable of storing four Li⁺ per monomer. The combination of storing four Li⁺ per monomer and a low molecular weight monomer results in a capacity of 330 mA h g^?1, a record for this class of material. The additional redox events responsible for added Li⁺ storage occur between 3.0 and 3.6 V versus Li/Li⁺ resulting in an average discharge potential of 2.5 V versus Li/Li⁺. These metrics combined yield a high energy density of 825 W h kg^?1 which is a 55% improvement over commercial lithium cobalt oxide. The high performance of LiDHAQS makes it a promising material for next generation Li⁺ cathodes.     

Decoupling the Ionic Conductivity and Elastic Modulus of Gel Electrolytes: Fully Zwitterionic Copolymer Scaffolds in Lithium Salt/Ionic Liquid Solutions

A critical barrier to overcome in the development of solid‐state electrolytes for lithium batteries is the trade‐off between sacrificing ionic conductivity for enhancement of mechanical stiffness. Here, a physically cross‐linked, polymer‐supported gel electrolyte consisting of a lithium salt/ionic liquid solution featuring a fully zwitterionic (ZI) copolymer network is introduced for rechargeable lithium‐based batteries. The ZI scaffold is synthesized using a 3:1 molar ratio of 2‐methacryloyloxyethyl phosphorylcholine and sulfobetaine vinylimidazole, and the total polymer content is varied between 1.1 and 12.5 wt%. Room‐temperature ionic conductivity values comparable to the base liquid electrolyte (≈1 mS cm^?1) are achieved in ZI copolymer‐supported gels that display compressive elastic moduli as large as 14.3 MPa due to ZI dipole–dipole cross‐links. Spectroscopic characterization suggests a change in the Li⁺ coordination shell upon addition of the zwitterions, indicative of strong Li⁺···ZI group interactions. Li⁺ transference number measurements reveal an increase in Li⁺ conductivity within a ZI gel electrolyte ( nearly doubles). ZI gels display enhanced stability against Li metal, dendrite suppression, and suitable charge–discharge performance in a graphite|lithium nickel cobalt manganese oxide cell. Fully ZI polymer networks in nonvolatile, ionic liquid‐based electrolytes represent a promising approach toward realizing highly conductive, mechanically rigid gels for lithium battery technologies.     

Triple helix formation and disulphide bonding during the biosynthesis of glomerular basement membrane collagen.

White erythrocyte membranes, or ghosts, were monoconcave discocytes when incubated in 50mM N-tris (hydroxymethyl) methyl-2-aminoethane sulfonic acid titrated to pH 7.4 with triethanolamine. If 3mM MgCl₂ was included in the incubation medium, the ghosts were predominantly echinocytes. The echinocytic form could also be induced by Co⁺⁺, Ni⁺⁺, Li⁺, Na⁺, K⁺, $\text{NH}{}_4{}^{\mathrm{+}}$ and tetramethylammonium ion, all as chloride salts. The concentration of cation necessary for 50% of the ghosts to be echinocytes was correlated with the hydrated charge density of the cation with the most highly charged cations being the most effective. The cations Ca⁺⁺, Sr⁺⁺, Ba⁺⁺ and La⁺⁺⁺, (also as chloride salts) did not induce the normal echinocytic form, but at high levels induced a few misshapen forms with some resemblance to echinocytes. Instead Ca⁺⁺, Sr⁺⁺, Ba⁺⁺ and La⁺⁺⁺ suppressed the formation of echinocytes in the presence of Mg⁺⁺ and other ions. This suggests the presence of a specific Ca⁺⁺ binding site important to shape control in the erythrocyte membrane.     

Further Studies on the Roles of Sodium and Potassium in the Generation of the Electro-Olfactogram : Effects of mono-, di-, and trivalent cations

In the negative EOG-generating process a cation which can substitute for Na⁺ was sought among the monovalent ions, Li⁺, Rb⁺, Cs⁺, NH₄⁺, and TEA⁺, the divalent ions, Mg⁺⁺, Ca⁺⁺, Sr⁺⁺, Ba⁺⁺, Zn⁺⁺, Cd⁺⁺, Mn⁺⁺, Co⁺⁺, and Ni⁺⁺, and the trivalent ions, Al⁺⁺⁺ and Fe⁺⁺⁺. In Ringer solutions in which Na⁺ was replaced by one of these cations the negative EOG's decreased in amplitude and could not maintain the original amplitudes. In K⁺-Ringer solution in which Na⁺ was replaced by K⁺, the negative EOG's reversed their polarity. Recovery of these reversed potentials was examined in modified Ringer solutions in which Na⁺ was replaced by one of the above cations. Complete recovery was found only in the normal Ringer solution. Thus, it was clarified that Na⁺ plays an irreplaceable role in the generation of the negative EOG's. The sieve hypothesis which was valid for the positive EOG-generating membrane or IPSP was not found applicable in any form to the negative EOG-generating membrane. The reversal of the negative EOG's found in K⁺- , Rb⁺- , and Ba⁺⁺-Ringer solutions was attributed to the exit of the internal K⁺. It is, however, not known whether or not Cl^- permeability increases in these Na⁺-free solutions and contributes to the generation of the reversed EOG's.     

Junctional membrane permeability

Summary Substitution of extracellular Na⁺ by Li⁺ causes depression of junctional membrane permeability inChironomus salivary gland cells; within 3 hr, permeability falls to so low a level that neither fluorescein nor the smaller inorganic ions any longer traverse the junctional membrane in detectable amounts (uncoupling). The effect is Li-specific: if choline⁺ is the Na⁺ substitute, coupling is unchanged. The Li-produced uncoupling is not reversed by restitution of Na⁺. Long-term exposure (>1 hr) of the cells to Ca, Mg-free medium leads also to uncoupling. This uncoupling is fully reversible by early restitution of Ca⁺⁺ or Mg⁺⁺. Coupling is maintained in the presence of either Ca⁺⁺ or Mg⁺⁺, so long as the total divalent concentration is about 12mm. The uncoupling in Ca, Mg-free medium ensues regardless of whether the main monovalent cation is Na, Li or choline.The uncouplings are accompanied by cell depolarization. Repolarization of the cells by inward current causes restoration of coupling; the junctional conductance rises again to its normal level. The effect was shown for Li-produced uncoupling, for uncoupling by prolonged absence of external Ca⁺⁺ and Mg⁺⁺, and for uncoupling produced by dinitrophenol. In all cases, the recoupling has the same features: (1) it develops rapidly upon application of the polarizing current; (2) it is cumulative; (3) it is transient, but outlasts the current; and (4) it appears not to depend on the particular ions carrying the current from the electrodes to the cell. The recoupling is due to repolarization of nonjunctional cell membrane; recoupling can be produced at zero net currernt through the junctional membrane. Recoupling takes place also as a result of chemically produced repolarization; restoration of theK gradients in uncoupled cells causes partial recoupling during the repolarization phase.An explanation of the results on coupling is proposed in terms of known mechanisms of regulation of Ca⁺⁺ flux in cells. The uncouplings are explained by actions raising the Ca⁺⁺ level in the cytoplasmic environment of the junctional membranes; the recoupling is explained by actions lowering this Ca⁺⁺ level.     

A New Perspective on the Role of A‐Site Cations in Perovskite Solar Cells

As the race toward higher efficiency for inorganic/organic hybrid perovskite solar cells (PSCs) is becoming highly competitive, a design scheme to maximize carrier transport toward higher power efficiency has been urgently demanded. In this study, a hidden role of A‐site cations of PSCs in carrier transport, which has been largely neglected is unraveled, i.e., tuning the Fröhlich electron–phonon (e–ph) coupling of longitudinal optical (LO) phonon by A‐site cations. The key for steering Fröhlich polaron is to control the interaction strength and the number of proton (or lithium) coordination to halide ions. The coordination to I^? alleviates electron–phonon scattering by either decreasing the Born effective charge or absorbing the LO motion of I. This novel principle discloses low electron–phonon coupling in several promising organic cations including hydroxyl–ammonium cation (NH₃OH⁺), hydrazinium cation (NH₃NH₂⁺) and possibly Li⁺ solvating methylamine (Li⁺???NH₂CH₃), on a par with methyl–ammonium cations. A new perspective on the role of A‐site cations could help in improving power efficiency and accelerating the application of PSCs.     

Li/Na exchange and Li active transport in human lymphoid cells U937 cultured in lithium media

Lithium transport across the cell membrane is interesting in the light of general cell physiology and because of its alteration during numerous human diseases. The mechanism of Li⁺ transfer has been studied mainly in erythrocytes with a slow kinetics of ion exchange and therefore under the unbalanced ion distribution. Proliferating cultured cells with a rapid ion exchange have not been used practically in study of Li⁺ transport. In the present paper, the kinetics of Li⁺ uptake and exit, as well as its balanced distribution across the plasma membrane of U937 cells, were studied at minimal external Li⁺ concentrations and after the whole replacement of external Na⁺ for Li⁺. It is found that a balanced Li⁺ distribution attained at a high rate similar to that for Na⁺ and Cl^? and that Li⁺/Na⁺ discrimination under balanced ion distribution at 1–10 mM external Li⁺ stays on 3 and drops to 1 following Na, K-ATPase pump blocking by ouabain. About 80% of the total Li⁺ flux across the plasma membrane under the balanced Li⁺ distribution at 5 mM external Li⁺ accounts for the equivalent Li⁺/Li⁺ exchange. The majority of the Li⁺ flux into the cell down the electrochemical gradient is a flux through channels and its small part may account for the NC and NKCC cotransport influxes. The downhill Li⁺ influxes are balanced by the uphill Li⁺ efflux involved in Li⁺/Na⁺ exchange. The Na⁺ flux involved in the countertransport with the Li⁺ accounts for about 0.5% of the total Na⁺ flux across the plasma membrane. The study of Li⁺ transport is an important approach to understanding the mechanism of the equivalent Li⁺/Li⁺/Na⁺/Na⁺ exchange, because no blockers of this mode of ion transfer are known and it cannot be revealed by electrophysiological methods. Cells cultured in the medium where Na⁺ is replaced for Li⁺ are recommended as an object for studying cells without the Na,K-ATPase pump and with very low intracellular Na⁺ and K⁺ concentration.     

Dendrite‐Suppressed Lithium Plating from a Liquid Electrolyte via Wetting of Li3N

Lithium metal is an ultimate anode material to provide the highest energy density for a given cathode by providing a higher capacity and cell voltage. However, lithium is not used as the anode in commercial lithium‐ion batteries because electrochemical dendrite formation and growth during charge can induce a cell short circuit that ignites the flammable liquid electrolyte. Plating of lithium through a bed of Li₃N particles is shown to transform dendrite growth into a 3D lithium network formed by wetting the particle surfaces; plating through a Li₃N particle is without dendrite nucleation. The Li₃N particles create a higher overpotential during Li deposition than that with dendrite growth in galvanostatic charge/discharge tests. The characteristic overpotential increase is correlated with the morphological changes and a more isotropic growth behavior. The Li₃N‐modified Li electrode shows a stable cycling performance at 0.5 and 1.0 mA cm^?2 for more than 100 cycles. The origin of the bonding responsible for wetting of the Li₃N particles by lithium and for plating through a Li₃N particle is discussed.     

Conductive and Catalytic Triple‐Phase Interfaces Enabling Uniform Nucleation in High‐Rate Lithium–Sulfur Batteries

Rechargeable lithium–sulfur batteries have attracted tremendous scientific attention owing to their superior energy density. However, the sulfur electrochemistry involves multielectron redox reactions and complicated phase transformations, while the final morphology of solid‐phase Li₂S precipitates largely dominate the battery's performance. Herein, a triple‐phase interface among electrolyte/CoSe₂/G is proposed to afford strong chemisorption, high electrical conductivity, and superb electrocatalysis of polysulfide redox reactions in a working lithium–sulfur battery. The triple‐phase interface effectively enhances the kinetic behaviors of soluble lithium polysulfides and regulates the uniform nucleation and controllable growth of solid Li₂S precipitates at large current density. Therefore, the cell with the CoSe₂/G functional separator delivers an ultrahigh rate cycle at 6.0 C with an initial capacity of 916 mAh g^?1 and a capacity retention of 459 mAh g^?1 after 500 cycles, and a stable operation of high sulfur loading electrode (2.69–4.35 mg cm^?2). This work opens up a new insight into the energy chemistry at interfaces to rationally regulate the electrochemical redox reactions, and also inspires the exploration of related energy storage and conversion systems based on multielectron redox reactions.