Ion Flux Research Articles

The chemo-mechanics of initiation of crack advance in Niobium Tungsten Oxide single crystals due to delithiation

Niobium tungsten oxide (NWO) micron-sized single crystals show promise as the active particles in the anodes of lithium ion batteries due to their fast charge/discharge and high storage capabilities. Within the “block” phases such as Nb16W5O55, Nb14W3O44 and the HNb2O5 polymorph, Li ion diffusion occurs in a unidirectional manner along a single axis of the crystal and lithiation/delithiation results in significant length changes in this direction. A chemo-mechanics analysis is developed for delithiation of an NWO “block” phase single crystal that contains a pre-existing flaw in the form of a through-thickness edge crack. Galvanostatic delithiation occurs by the flux of Li ions through the free ends of the crystal and also through the faces of the crack, with concomitant shrinkage of the surface layer over a depth equal to that of the crack. The induced tensile stress in the surface layer can be of sufficient magnitude to advance the crack in the NWO crystal, consistent with recent experimental observations for Nb14W3O44. A 2D full-field finite element version of the chemo-mechanics model is used to explore the sensitivity of cracking to crack length, delithiation rate of the anode, diffusivity of Li ions within the NWO single crystal storage particle and to the kinetics of Li ion transfer across the particle surface-electrolyte interface. Additionally, a simplified, lumped parameter model is developed by assuming that the Li ion occupancy is spatially uniform in a surface layer that extends to a depth of the pre-existing crack, and has a spatially uniform but different value than that of the underlying core of the particle. This simplified model can be expressed as a set of first order differential equations in time and gives the main features of delithiation and the associated transient stress state in the single crystal. Both the full model and the lumped parameter version predict that crack advance from a pre-existing defect is triggered by a high delithiation rate, consistent with the experimental literature.

Resveratrol Inhibits VDAC1-Mediated Mitochondrial Dysfunction to Mitigate Pathological Progression in Parkinson's Disease Model.

An increase in α-synuclein (α-syn) levels and mutations in proteins associated with mitochondria contribute to the development of familial Parkinson's disease (PD); however, the involvement of α-syn and mitochondria in idiopathic PD remains incompletely understood. The voltage-dependent anion channel I (VDAC1) protein, which serves as a crucial regulator of mitochondrial function and a gatekeeper, plays a pivotal role in governing cellular destiny through the control of ion and respiratory metabolite flux. The ability of resveratrol (RES), which is a potent phytoalexin with antioxidant and anti-inflammatory properties, to regulate VDAC1 in PD is unknown. The objective of this study was to evaluate the role of VDAC1 in the pathological process of PD and to explore the mechanism by which resveratrol protects dopaminergic neurons by regulating VDAC1 to maintain the mitochondrial permeability transition pore (mPTP) and calcium ion balance. The effects of RES on the motor and cognitive abilities of A53T mice were evaluated by using small animal behavioral tests. Various techniques, including immunofluorescence staining, transmission electron microscopy, enzyme-linked immunoadsorption, quantitative polymerase chain reaction (PCR), and Western blotting, among others, were employed to assess the therapeutic impact of RES on neuropathy associated with PD and its potential in regulating mitochondrial VDAC1. The findings showed that RES significantly improved motor and cognitive dysfunction and restored mitochondrial function, thus reducing oxidative stress levels in A53T mice. A significant positive correlation was observed between the protein expression level of VDAC1 and mitochondrial α-syn expression, as well as disease progression, whereas no such correlation was found in VDAC2 and VDAC3. Administration of RES resulted in a significant decrease in the protein expression of VDAC1 and in the protein expression of α-syn both in vivo and in vitro. In addition, we found that RES prevents excessive opening of the mPTP in dopaminergic neurons. This may prevent the abnormal aggregation of α-syn in mitochondria and the release of mitochondrial apoptosis signals. Furthermore, the activation of VDAC1 reversed the resveratrol-induced decrease in the accumulation of α-syn in the mitochondria. These findings highlight the potential of VDAC1 as a therapeutic target for PD and identify the mechanism by which resveratrol alleviates PD-related pathology by modulating mitochondrial VDAC1.

Effects of power on ion behaviors in radio-frequency magnetron sputtering of indium tin oxide (ITO)

This study delves into ion behavior at the substrate position within RF magnetron discharges utilizing an indium tin oxide (ITO) target. The positive ion energies exhibit an upward trajectory with increasing RF power, attributed to heightened plasma potential and initial emergent energy. Simultaneously, the positive ion flux escalates owing to amplified sputtering rates and electron density. Conversely, negative ions exhibit broad ion energy distribution functions (IEDFs) characterized by multiple peaks. These patterns are clarified by a combination of radiofrequency oscillation of cathode voltage and plasma potential, alongside ion transport time. This elucidation finds validation in a one-dimensional model encompassing the initial ion energy. At higher RF power, negative ions surpassing 100 eV escalate in both flux and energy, posing a potential risk of sputtering damages to ITO layers.

On the Formation Mechanism of Martian Dayside Ionospheric Plasma Depletion Events

AbstractPlasma Depletion Events (PDEs) are characterized by abrupt, localized reductions in ionospheric plasma density at least by an order of magnitude decrease. These events are observed over a limited range of altitudes, typically spanning a few tens of kilometers. We use Mars Atmosphere and Volatile Evolution spacecraft data to investigate the properties and possible formation mechanism of daytime PDEs, typically observed at altitudes above 250 km. We show, using two example events and statistical analysis, that the depletion events are associated with electrostatic fluctuations and increased electron temperatures. The events are further accompanied by enhanced fluxes of suprathermal electrons and light energetic ions. These are indicative of local plasma heating, possibly mediated by the electrostatic fluctuations. The heated plasma may eventually escape from the depletion region through the ambipolar diffusion.

Mathematical modeling of rare earth element separation in electrodialysis with adjacent anion exchange membranes and ethylenediaminetetraacetic acid as chelating agent

This research delves into the effective use of electrodialysis for the separation of rare earth elements (REEs), specifically separating dysprosium (Dy) from praseodymium (Pr) and neodymium (Nd). A robust mathematical model based on the extended Nernst-Planck equation is introduced, simulating the process within a configuration that includes two adjacent anion exchange membranes. The model integrates aspects such as feed equilibrium, ion exchange within the membrane, and overall ion flux. Validation of the model's predictability was conducted through Chi-squared tests and root mean square error (RMSE) calculations, affirming its capability to accurately predict ion concentrations across different compartments. The study examines essential parameters such as applied voltage, rinse solution concentration, and feed concentration, assessing their impacts on separation performance and energy efficiency. Results indicate that higher voltages above 8 V, while speeding up separation, detrimentally impact energy use. It also highlights a critical balance in rinse solution concentration; lower concentrations below 0.05 mol/L enhance energy efficiency but may undercut separation efficacy due to early depletion. A linear correlation between the necessary rinse concentration and feed concentration was established, with higher feed concentrations demonstrating reduced specific energy consumption, thus enhancing overall efficiency. However, challenges remain in current efficiency due to the independent migration of SO42− ions in this specific setup. The findings advocate exploring alternative configurations, like alternating cation and anion exchange membranes, to optimize both environmental and economic aspects of REE separation. This study provides valuable insights and recommendations for refining electrodialysis systems in REE processing, contributing to sustainable and cost-effective electrodialysis systems.

Recent progress in heterostructured materials for room‐temperature sodium‐sulfur batteries

AbstractRoom‐temperature sodium‐sulfur (RT Na‐S) batteries are a promising next‐generation energy storage device due to their low cost, high energy density (1274 Wh kg−1), and environmental friendliness. However, RT Na‐S batteries face a series of vital challenges from sulfur cathode and sodium anode: (i) sluggish reaction kinetics of S and Na2S/Na2S2; (ii) severe shuttle effect from the dissolved intermediate sodium polysulfides (NaPSs); (iii) huge volume expansion induced by the change from S to Na2S; (iv) continuous growth of sodium metal dendrites, leading to short‐circuiting of the battery; (v) huge volume expansion/contraction of sodium anode upon sodium plating/stripping, causing uncontrollable solid‐state electrolyte interphase growth and “dead sodium” formation. Various strategies have been proposed to address these issues, including physical/chemical adsorption of NaPSs, catalysts to facilitate the rapid conversion of NaPSs, high‐conductive materials to promote ion/electron transfer, good sodiophilic Na anode hetero‐interface homogenized Na ions flux and three‐dimensional porous anode host to buffer the volume expansion of sodium. Heterostructure materials can combine these merits into one material to realize multifunctionality. Herein, the recent development of heterostructure as the host for sulfur cathode and Na anode has been reviewed. First of all, the electrochemical mechanisms of sulfur cathode/sodium anode and principles of heterostructures reinforced Na‐S batteries are described. Then, the application of heterostructures in Na‐S batteries is comprehensively examined. Finally, the current primary avenues of employing heterostructures in Na‐S batteries are summarized. Opinions and prospects are put forward regarding the existing problems in current research, aiming to inspire the design of advanced and improved next‐generation Na‐S batteries.

An alternative 3′ splice site of PeuHKT1;3 improves the response to salt stress through enhancing affinity to K+ in Populus

Alternative splicing (AS) serves as a crucial post-transcriptional regulator in plants that contributes to the resistance to salt stress. However, the underlying mechanism is largely unknown. In this research, we identified an important AS transcript in Populus euphratica, PeuHKT1:3a, generated by alternative 3′ splice site splicing mode that resulted in the removal of 252 bases at the 5′ end of the first exon in PeuHKT1:3. Protein sequence comparison showed that the site of AS occurred in PeuHKT1:3 is located at a crucial Ser residue within the first pore-loop domain, which leads to inefficient K+ transport in HKT I-type transporters. Expressing PeuHKT1;3a in an axt3 mutant yeast strain can effectively compensate for the lack of intracellular K+, whereas the expression of PeuHKT1;3 cannot yield the effect. Furthermore, in transgenic Arabidopsis and poplar plants, it was observed that lines expressing PeuHKT1;3a exhibited greater salt tolerance compared to those expressing the PeuHKT1;3 strain. Analysis of ion content and flux demonstrated that the transgenic PeuHKT1;3a line exhibited significantly higher K+ content compared to the PeuHKT1;3 line, while there was no significant difference in Na+ content. In conclusion, our findings revealed that AS can give rise to novel variants of HKT I-type proteins in P. euphratica with modified K+ selectivity to keep a higher K+/Na+ ratio to enhanced salt tolerance.

The effects of microplastics on ionoregulatory processes in the gills of freshwater fish and invertebrates: A prospective review

From review of the very few topical studies to date, we conclude that while effects are variable, microplastics can induce direct ionoregulatory disturbances in freshwater fish and invertebrates. However, the intensity depends on microplastic type, size, concentration, and exposure regime. More numerous are studies where indirect inferences about possible ionoregulatory effects can be drawn; these indicate increased mucus production, altered breathing, histopathological effects on gill structure, oxidative stress, and alterations in molecular pathways. All of these could have negative effects on ionoregulatory homeostasis. However, previous research has suffered from a lack of standardized reporting of microplastic characteristics and exposure conditions. Often overlooked is the fact that microplastics are dynamic contaminants, changing over time through degradation and fragmentation and subsequently exhibiting altered surface chemistry, notably an increased presence and diversity of functional groups. The same functional groups characterized on microplastics are also present in dissolved organic matter, often termed dissolved organic carbon (DOC), a class of substances for which we have a far greater understanding of their ionoregulatory actions. We highlight instances in which the effects of microplastic exposure resemble those of DOC exposure. We propose that in future microplastic investigations, in vivo techniques that have proven useful in understanding the ionoregulatory effects of DOC should be used including measurements of transepithelial potential, net and unidirectional radio-isotopic ion flux rates, and concentration kinetic analyses of uptake transport. More sophisticated in vitro approaches using cultured gill epithelia, Ussing chamber experiments on gill surrogate membranes, and scanning ion selective electrode techniques (SIET) may also prove useful. Finally, in future studies we advocate for minimum reporting requirements of microplastic properties and experimental conditions to help advance this important emerging field.

Experimental study of the plasma flow created by a low-power helicon source and approaches to increase the average energy of its ion component

The article presents the results of an experimental study of the characteristics of a low-power helicon ion source. Particular attention is paid to the parameters of the particle flow emerging from the source and the possibilities for increasing ion energy. It was found that the voltage drop at the output of the source is small (10–15 V), and the main voltage drop is localized at the grounded elements. The ion flux density non-monotonically depends on the magnetic field, while the ion energy remains constant. Applying a constant voltage to the additional electrode inside the discharge chamber does not increase the potential drop at the output of the source. Switching to a lower operating frequency or narrower output orifices allows increasing ion energy, but leads to a decrease in ion flux. At the exit from the source, in the presence of a magnetic field, a directed flow of electrons was detected, the energy of which increases significantly with increasing magnetic field induction. The presence of wave processes in the discharge chamber, which may be responsible for the appearance of an accelerated electron flow, has been demonstrated.

Enhanced boron removal without pre-pH adjustment via redox-mediated electrodialysis assisted by ion-exchange resins

Boron presents challenges in desalination owing to its small size and lack of charge. While various methods, such as reverse osmosis, capacitive deionization, and electrodeionization, have been utilized to control boron, they often suffer from high levels of energy consumption and complex processes requiring pH adjustment to generate the charged form of boron. Herein, we introduce a novel approach, i.e., redox-mediated electrodialysis (redox-ED) assisted by ion-exchange resins, aimed at energy-efficient boron control without requiring pH adjustment. Our system displays a remarkable boron removal efficiency of 99% with a low energy consumption of 0.009 kWh/g (0.09 kWh/m3). These results are likely due to the dissociation of water on the surface of the ion-exchange resins, which led to a local pH gradient and reduced systemic resistance through additional ion flux. Furthermore, via techno-economic analysis, the total cost of the redox-ED for boron removal revealed a 50% reduction with the scale-up strategy of electrode stacking, compared to those of traditional EDI systems. Overall, this study demonstrates the new potential of a sustainable boron removal technology without pH adjustment through the redox-ED system assisted by ion-exchange resins, providing an attractive option applicable to the boron removal industry.

Engineering Sb/Zn4(OH)6SO4·5H2O interfacial layer by in situ chemically reacting for stable Zn anode

Rechargeable aqueous zinc ion batteries with abundant resources and high safety have gained extensive attention in energy storage technology. However, the cycle stability is largely limited by notorious Zn dendrite growth and water-induced interfacial side reactions. Here, a uniform and robust protection layer consisting of metal antimony (Sb) nanoparticles and micrometer-size sheets Zn4(OH)6SO4·5H2O (ZHS) is purposely designed to stabilize Zn anode via an in situ chemical reaction strategy. The two-phase protection layers (Sb/ZHS) induce a reinforcement effect on the Zn anode (Zn@Sb/ZHS). Specifically, Sb nanoparticles play the part of nucleation sites to facilitate uniform Zn plating and homogenize the electric field around the Zn surface. ZHS micrometer-size sheets possess sufficient electrolyte wettability, fast ion transfer kinetics, and anti-corrosion, thus guaranteeing uniform ion flux and inhibiting H2O decomposition. As expected, the symmetric Zn@Sb/ZHS//Zn@Sb/ZHS cells achieve a minimal voltage hysteresis and a reversible cycle of over 2000 h at 1 mA cm−2. By pairing with the MnO2 cathode, the full cell exhibits a significantly improved stability (∼94.17 % initial capacity after 1500 cycles). This study provides a new strategy to design artificial protection layers.

Dependence of Lunar Pickup Ion Flux on Source Location: ARTEMIS Observations

The Moon is enveloped in an exosphere, which is comprised of a variety of neutral atoms and molecules. Once exospheric neutrals are ionized by photons, protons, or electrons from the Sun, the resulting ions are accelerated by the electromagnetic fields of their surroundings and can thereby travel away from their source locations. These ions are the so-called pickup ions and are frequently observed by the two Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon’s Interaction with the Sun (ARTEMIS) spacecraft. In this study, we identify 115 events from an 11 yr period of ARTEMIS observations, which contain a total of 11,987 samples for our statistics. By using analytical ion trajectory calculations, we trace the source location of each pickup ion observation. Most pickup ion trajectories originate near the subsolar point, consistent with the efficiency of sputtering. We find that the flux of pickup ions strongly anticorrelates with the source altitude, providing indirect evidence of decreasing exospheric ion flux with increasing altitude. We also find that the flux of pickup ions does not show a significant relationship with the crustal magnetic field intensity. This implies that a depression of sputtering efficiency or the trapping of near-surface freshly born ions by a crustal magnetic anomaly may not reduce the subsequent pickup ion flux as effectively as expected. In summary, the present paper provides a statistical view of lunar pickup ion fluxes in association with the altitude, local time, and local crustal magnetic field of their source locations.

Characterization and Performance Evaluation of Digital Light Processing 3D Printed Functional Anion Exchange Membranes in Electrodialysis

With the rapid development of 3D printing technologies, more attention has been focused on using 3D printing for the fabrication of membranes. This study investigated the application of digital light processing (DLP) 3D printing combined with quaternization processes to develop dense anion exchange membranes (AEMs) for electrodialysis (ED) separation of Cl− and SO42− ions. It was discovered that at optimal curing times of 40 min, the membrane pore density was significantly enhanced and the surface roughness was reduced, and this resulted in an elevation of desalination rates (97.5–98.7%) and concentration rates (165.8–174.1%) of the ED process. Furthermore, increasing the number of printed layers improved the membranes’ overall polymerization and performance, with double-layer printing showing superior ion flux. This study also highlights the impact of the polyethylene glycol diacrylate (PEGDA) molecular weight on membrane efficacy, where PEGDA-700 outperformed PEGDA-400 in ion transport capabilities and desalination efficiency. Additionally, higher 4-vinylbenzyl chloride (VBC) content improved the quaternary ammonium group concentration and membrane conductivity, and hence elevated the ED performance. Under optimized conditions, DLP 3D printed membranes demonstrated exceptional selectivity of 24.0 for Cl−/SO42− and a selective purity of 81.4%. With a current density of 400 A/m2, the current efficiency and energy consumption were in the range of 82.4% to 99.7%, and 17.2 to 25.4 kW‧h‧kg−1, respectively, showcasing the potential of advanced manufacturing techniques in creating efficient and functional ion exchange membranes.

Nano-optogenetics for Disease Therapies.

Optogenetic, known as the method of 21 centuries, combines optic and genetic engineering to precisely control photosensitive proteins for manipulation of a broad range of cellular functions, such as flux of ions, protein oligomerization and dissociation, cellular intercommunication, and so on. In this technique, light is conventionally delivered to targeted cells through optical fibers or micro light-emitting diodes, always suffering from high invasiveness, wide-field illumination facula, strong absorption, and scattering by nontargeted endogenous substance. Light-transducing nanomaterials with advantages of high spatiotemporal resolution, abundant wireless-excitation manners, and easy functionalization for recognition of specific cells, recently have been widely explored in the field of optogenetics; however, there remain a few challenges to restrain its clinical applications. This review summarized recent progress on light-responsive genetically encoded proteins and the myriad of activation strategies by use of light-transducing nanomaterials and their disease-treatment applications, which is expected for sparking helpful thought to push forward its preclinical and translational uses.

Soil-inspired multi-stage heterogeneous nanochannel membranes for enhanced osmotic energy conversion

The nanofluidic ion transporting channels for harvesting blue osmotic energy between river water and seawater have received great attentions recently. However, the design of excellent ion selective nanochannel membranes while retaining high mechanical strength and ion flux remains a challenge. Herein, we present a novel multi-stage heterogeneous nanochannel membranes consisting of alternating TEMPO oxidized cellulose nanofibers (TOCNFs) and MXene layers inspired by the multi-layer structure of natural soil. The ingenious binding of “soft layer” of TOCNFs acting as ion selective layer and “hard layer” of MXene acting as ion permeable/structural support layer contributes to the fast cationic transport through the robust nanochannel membranes. In hypersaline solutions, a remarkable power density of 95.13 W m−2 is produced. This work provides a new strategy for heterogeneous nanochannel membranes for osmotic energy generation.

Effects of exogenous chloride ions on the migration and transformation of Cd in a soil-rice system

Soil cadmium (Cd) contamination has emerged as a significant global environmental concern, posing numerous risks to individual organisms and entire ecosystems. Concurrently, the global increase in pesticide usage has elevated the influx of chloride ions (Cl−) into the soil. Given Cl−’s robust ability to coordinate and complex with various heavy metal ions, understanding its influence on the migration and transformation of Cd in soil-rice systems is essential for the rational application of pesticides and the effective mitigation of soil heavy metal pollution. In this paper, we explained the effect of Cl− on the environmental behavior of Cd in the soil-rice system in terms of growth traits, Cd uptake and accumulation by rice, and Cd solid-solution phase interface behavior through pot experiments and sand culture experiments. The results showed that Cd concentrations in all parts of the rice treated with CaCl2 during the filling period were lower than those in the Ca(NO3)2-treated group, with Cd accumulation diminishing as Cl− concentration increased. This suggests that the filling period is critical for Cd uptake and accumulation in rice. Unlike the accompanying anion NO3−, exogenous Cl− reduced Cd concentrations in the soil solution but increased them in rice. Notably, when the Cd/Cl ratio ranged from 0.625 to 2.5, Cl− formed predominantly CdCl+-complexes with free Cd2+ in the soil solution, enhancing the mobilization of Cd bound to soil particles and its subsequent absorption by rice. This study aims to assess Cl−’s effect on Cd migration and transformation in soil-rice systems, providing insights for safe rice production on Cd-contaminated soils and rational use of chlorine-containing pesticides.

Stable anode/separator interface enabled by graft modification of polypropylene separator via electron beam irradiation technique toward high-performance sodium metal batteries

Sodium metal batteries (SMBs) are considered as strong alternatives to lithium-ion batteries (LIBs), due to the inherent merits of sodium metal anodes (SMAs) including low redox potential (−2.71 V vs. SHE), high theoretical capacity (1166 mAh g−1), and abundant resources. However, the uncontrollable Na dendrite growth has significantly impeded the practical deployment of SMBs. Separator modification has emerged as an effective strategy for substantially enhancing the performance of SMAs. Herein, for the first time, we present the successful grafting polyacrylic acid (PAA) onto polypropylene (PP) separators (denoted as PP-g-PAA) using highly efficient electron beam (EB) irradiation to improve the cyclability of SMAs. The polar carboxyl groups of PAA can facilitate the electrolyte wetting and provide ample mechanical strength to resist dendrite penetration. Consequently, the regulation of Na+ ion flux enables uniform Na+ deposition with dendrite-free morphology, facilitated by the favorable anode/separator interface. The PP-g-PAA separator significantly enhances the cyclability of fabricated cells. Notably, the lifespan of Na||Na symmetric cells can be extended up to 5519 h at 1 mA cm−2 and 1 mAh cm−2. The stable design of the anode/separator interface achieved through polyolefin separator modification presented in this study holds promise for the further advancement of next-generation advanced battery systems.

Dissecting the causal polymorphism of the Lr67res multipathogen resistance gene.

Partial resistance to multiple biotrophic fungal pathogens in wheat (Triticum aestivum L.) is conferred by a variant of the Lr67 gene, which encodes a hexose-proton symporter. Two mutations (G144R and V387L) differentiate the resistant and susceptible protein variants (Lr67res and Lr67sus). Lr67res lacks sugar transport capability and was associated with anion transporter-like properties when expressed in Xenopus laevis oocytes. Here, we extended this functional characterization to include yeast and in planta studies. The Lr67res allele, but not Lr67sus, induced sensitivity to ions in yeast (including NaCl, LiCl, and KI), which is consistent with our previous observations that Lr67res expression in oocytes induces novel ion fluxes. We demonstrate that another naturally occurring single amino acid variant in wheat, containing only the Lr67G144R mutation, confers rust resistance. Transgenic barley plants expressing the orthologous HvSTP13 gene carrying the G144R and V387L mutations were also more resistant to Puccinia hordei infection. NaCl treatment of pot-grown adult wheat plants with the Lr67res allele induced leaf tip necrosis and partial leaf rust resistance. An Lr67res-like function can be introduced into orthologous plant hexose transporters via single amino acid mutation, highlighting the strong possibility of generating disease resistance in other crops, especially with gene editing.

Synergy of modulating in-plane pores and zincophilic sites on the flexible graphene paper for efficient and dendrite-free hosted Zn anode

The practical advancement of Zn-ion batteries (ZIBs) in the portable/wearable electronics field is still hindered by the notorious Zn dendrites formation and the lack of an appropriate host to construct a highly effective flexible Zn anode. Herein, we present a three-dimensional (3D) N-doped graphene paper framework with abundant in-plane pores (rHGP-N) as an efficient Zn plating/stripping scaffold. Remarkably, the rHGP-N paper electrode exhibits an unprecedentedly low Zn nucleation overpotential of 5.2 mV and maintains a high average Coulombic efficiency (∼99.3%) over a superior long Zn plating/stripping cycling of 1400 h. DFT calculation results demonstrate that pyrrolic-nitrogen on graphene possesses the strongest adsorption energy for Zn2+, serving as zincophilic sites to guide Zn uniform nucleation. Moreover, the finite elements simulation results illustrate that flexible graphene paper with abundant in-plane pores can mitigate structural stress and inhibit the formation of Zn dendrites by spatially homogenizing Zn2+ ions flux throughout the entire electrode. The assembled ZIBs full cell (rHGP-N@Zn//rHGP-N@Mn3(PO4)2) demonstrates an impressive volumetric energy density of 77 mWh/cm3, as well as excellent flexibility and mechanical stability with negligible capacity decay under harsh deformation conditions. Our approach can be potentially utilized in designing dendrite-free metal-based flexible anodes for Mg, Ca, or Al-ion batteries.

A Precursor-Derived Ultramicroporous Carbon for Printing Iontronic Logic Gates and Super-Varactors.

A liquid precursor for 3D printing ultramicroporous carbons (pore width <0.7nm) to create a novel in-plane capacitive-analog of semiconductor-based diodes (CAPodes) is presented. This proof-of-concept integrates functional EDLCs into microstructured iontronic devices. The working principle is based on selective ion-sieving, controlling the size of the electrolyte ions, and the nanoporous sieving carbon's pore size. By blocking bulky electrolyte ions from entering the sub-nanometer pores, a unidirectional charging characteristic with controllable ion flux is achieved, leading to diodic U-I characteristics with a high rectification ratio. The liquid precursor approach enables successful printing of miniaturized in-plane CAPodes. A combination of inkjet and extrusion printing techniques with suitable inks is explored to fabricate electrode materials with engineered porosity. Deliberate fine-tuning of the ultramicroporous carbon's porosity and surface area is achieved using a customized carbon precursor and CO2 etching techniques. Electrochemical evaluation of the printed CAPodes demonstrates successful miniaturization compared with macroscopic film assembly. 3D manufacturing and miniaturization allow for the integration of CAPodes into logic gate circuits (OR, AND). For the first time, these switchable devices are used as variable capacitors in a high-pass filter application, adjusting the cut-off frequency of applied alternating voltage analogous to an I-MOS varactor.