Ion Transport Research Articles

Improved Mechanical Strength without Sacrificing Li-Ion Transport in Polymer Electrolytes.

Next-generation batteries demand solid polymer electrolytes (SPEs) with rapid ion transport and robust mechanical properties. However, many SPEs with liquid-like Li+ transport mechanisms suffer a fundamental trade-off between conductivity and strength. Dynamic polymer networks can improve bulk mechanics with minimal impact to segmental relaxation or ionic conductivity. This study demonstrates a system where a single polymer-bound ligand simultaneously dissociates Li+ and forms long-lived Ni2+ networks. The polymer comprises an ethylene oxide backbone and imidazole (Im) ligands, blended with Li+ and Ni2+ salts. Ni2+-Im dynamic cross-links result in the formation of a rubbery plateau resulting in, consequently, storage modulus improvement by a factor of 133× with the introduction of Ni2+ at rNi = 0.08, from 0.014 to 1.907 MPa. Even with Ni2+ loading, the high Li+ conductivity of 3.7 × 10-6 S/cm is retained at 90 °C. This work demonstrates that decoupling of ion transport and bulk mechanics can be readily achieved by the addition of multivalent metal cations to polymers with chelating ligands.

From Bulk to Interface: Solvent Exchange Dynamics and Their Role in Ion Transport and the Interfacial Model of Rechargeable Magnesium Batteries.

Multivalent battery chemistries have been explored in response to the increasing demand for high-energy rechargeable batteries utilizing sustainable resources. Solvation structures of working cations have been recognized as a key component in the design of electrolytes; however, most structure-property correlations of metal ions in organic electrolytes usually build upon favorable static solvation structures, often overlooking solvent exchange dynamics. We here report the ion solvation structures and solvent exchange rates of magnesium electrolytes in various solvents by using multimodal nuclear magnetic resonance (NMR) analysis and molecular dynamics/density functional theory (MD/DFT) calculations. These magnesium solvation structures and solvent exchange dynamics are correlated to the combined effects of several physicochemical properties of the solvents. Moreover, Mg2+ transport and interfacial charge transfer efficiency are found to be closely correlated to the solvent exchange rate in the binary electrolytes where the solvent exchange is tunable by the fraction of diluent solvents. Our primary findings are (1) most battery-related solvents undergo ultraslow solvent exchange coordinating to Mg2+ (with time scales ranging from 0.5 μs to 5 ms), (2) the cation transport mechanism is a mixture of vehicular and structural diffusion even at the ultraslow exchange limit (with faster solvent exchange leading to faster cation transport), and (3) an interfacial model wherein organic-rich regions facilitate desolvation and inorganic regions promote Mg2+ transport is consistent with our NMR, electrochemistry, and cryogenic X-ray photoelectron spectroscopy (cryo-XPS) results. This observed ultraslow solvent exchange and its importance for ion transport and interfacial properties necessitate the judicious selection of solvents and informed design of electrolyte blends for multivalent electrolytes.

Engineering a Low-Strain Si@TiSi2@NC Composites for High-Performance Lithium-Ion Batteries.

The huge volume expansion/contraction of silicon (Si) during the lithium (Li) insertion/extraction process, which can lead to cracking and pulverization, poses a substantial impediment to its practical implementation in lithium-ion batteries (LIBs). The development of low-strain Si-based composite materials is imperative to address the challenges associated with Si anodes. In this study, we have engineered a TiSi2 interface on the surface of Si particles via a high-temperature calcination process, followed by the introduction of an outermost carbon (C) shell, leading to the construction of a low-strain and highly stable Si@TiSi2@NC composite. The robust TiSi2 interface not only enhances electrical and ionic transport but also, more critically, significantly mitigates particle cracking by restraining the stress/strain induced by volumetric variations, thus alleviating pulverization during the lithiation/delithiation process. As a result, the as-fabricated Si@TiSi2@NC electrode exhibits a high initial reversible capacity (2172.7 mAh g-1 at 0.2 A g-1), superior rate performance (1198.4 mAh g-1 at 2.0 A g-1), and excellent long-term cycling stability (847.0 mAh g-1 after 1000 cycles at 2.0 A g-1). Upon pairing with LiNi0.6Co0.2Mn0.2O2 (NCM622), the assembled Si@TiSi2@NC||NCM622 pouch-type full cell exhibits exceptional cycling stability, retaining 90.1% of its capacity after 160 cycles at 0.5 C.

Ultramicrotomy‐Assisted Fabrication of Nanochannels for Efficient Ion Transport and Energy Generation

Ultramicrotomy‐Assisted Fabrication of Nanochannels for Efficient Ion Transport and Energy Generation

NCX1/Ca2+ promotes autophagy and decreases bortezomib activity in multiple myeloma through non-canonical NFκB signaling pathway

Although bortezomib (BTZ) is the cornerstone of anti-multiple myeloma (MM) therapy, the inevitable primary and secondary drug resistance still seriously affects the prognosis of patients. New treatment strategies are in need. Sodium-calcium exchanger 1 (NCX1) is a calcium-permeable ion transporter on the membrane, and our previous studies showed that low NCX1 confers inferior viability in MM cells and suppressed osteoclast differentiation. However, the effect of NCX1 on BTZ sensitivity of MM and its possible mechanism remain unclear. In this study, we investigated the effect of NCX1 on BTZ sensitivity in MM, focusing on cellular processes of autophagy and cell viability. Our results provide evidence that NCX1 expression correlates with MM disease progression and low NCX1 expression increases BTZ sensitivity. NCX1/Ca2+ triggered autophagic flux through non-canonical NFκB pathway in MM cells, leading to attenuated the sensitivity of BTZ. Knockdown or inhibition of NCX1 could potentiate the anti-MM activity of BTZ in vitro and vivo, and inhibition of autophagy sensitized NCX1-overexpressing MM cells to BTZ. In general, this work implicates NCX1 as a potential therapeutic target in MM with BTZ resistance and provides novel mechanistic insights into its vital role in combating BTZ resistance.

Recent Advances in Catalyst Design and Performance Optimization of Nanostructured Cathode Materials in Zinc-Air Batteries.

This review focuses on the advanced design and optimization of nanostructured zinc-air batteries (ZABs), with the aim of boosting their energy storage and conversion capabilities. The findings show that ZABs favor porous nanostructures owing to their large surface area, and this enhances the battery capacity, catalytic activity, and life cycle. In addition, the nanomaterials improve the electrical conductivity, ion transport, and overall battery stability, which crucially reduces dendrite growth on the zinc anodes and improves cycle life and energy efficiency. To obtain a superior performance, the importance of controlling the operational conditions and using custom nanostructural designs, optimal electrode materials, and carefully adjusted electrolytes is highlighted. In conclusion, porous nanostructures and nanoscale materials significantly boost the energy density, longevity, and efficiency of Zn-air batteries. It is suggested that future research should focus on the fundamental design principles of these materials to further enhance the battery performance and drive sustainable energy solutions.

Mg-Composition Dependent Cycle Stability in Zn<sub>1-x</sub>Mg<sub>x</sub>O Li-ion Battery: Transition from Electronic Transport-Limited to Ionic Transport Limited Cycles

This study explores Mg-composition dependent cycle stability in a Zn<sub>1-x</sub>Mg<sub>x</sub>O Li-ion battery, where battery cycles transition from an electronic transport-limited to an ionic transport limited regime. We investigated the impact of Mg doping in Zn<sub>1-x</sub>Mg<sub>x</sub>O nanocrystals on Li-ion battery performance, focusing on Mg compositions between x=0.05 and x=0.15. Mg composition dependent structural and electrical properties were explored using field effect transistors (FETs) and various microscopic/spectroscopic methods. The electronic conductivity was found to be sensitive to changes in Mg composition. Consistently, the initial capacity decreased with an increase in Mg composition, aligning with the reduction in electronic conductivity due to Mg doping. However, with successive cycles, the capacity became independent of the electronic conductivity, an outcome attributed to the formation of a solid-electrolyte interphase (SEI) and the conversion reactions. Initially, Mg doping reduces electronic conductivity due to increased carrier trapping, leading to lower discharge capacity. However, as cycling progresses, the impact of Mg doping diminishes. The formation of the SEI layer becomes more influential, significantly affecting Li-ion transport. Over time, factors like SEI formation, conversion reaction dynamics, and structural changes within the electrode start to dominate the battery's capacity, rather than the initial electronic conductivity influenced by Mg doping. This understanding can guide the development of materials with lower resistance, facilitating faster charging and discharging rates. More importantly, this study indicates that the initial capacity is closely tied to the conductivity of the Zn<sub>1-x</sub>Mg<sub>x</sub>O material.

131 DNA methylation profile in bovine fetal liver is affected by maternal vitamin and mineral supplementation during early gestation

Abstract Early gestation is the critical period for successful pregnancy establishment. During this period, maternal nutrition affects fetal development with potentially long-lasting consequences on offspring performance. Despite the known effects of vitamins and minerals on embryonic development, supplementation is still not a widely adopted practice. Here we focused on the effects of maternal vitamin and mineral supplementation from pre-breeding to d 83 of gestation. We hypothesized that the DNA methylation pattern of genes involved with fetal hepatic metabolism and function would be altered in response to vitamin and mineral supplementation during early gestation. Sixteen Angus crossbred heifers (~16 mo of age) were randomly assigned to either a treatment (vitamin and mineral supplementation, VTM, n = 8) or control (corn-based carrier without supplementation, NoVTM, n = 8) group. Supplemented heifers received 0.45 kg •heifer-1•d-1 of to provide 113 g of vitamin-mineral premix (Purina Wind & Rain Storm All-Season 7.5 Complete, Land O’Lakes, Inc., Arden Hills, MN) from d 71 to 148 before breeding to d 83 of gestation. All heifers received 100% of NRC recommended nutritional requirements targeting 0.28 kg •heifer-1•d-1 of gain. The heifers were bred through artificial insemination following a 7-d Co-Synch + CIDR estrus synchronization protocol. All pregnant heifers were surgically ovariohysterectomized on d 83, and liver samples were collected from the fetuses. DNA methylation profiles from 16 fetuses (8 per treatment) were determined using Reduced Representation Bisulfite Sequencing (RRBS). The analysis was conducted using methylKit pipeline where data was normalized using principal components. We identified 794 differentially methylated cytosines (DMCs) for the control (NoVTM) vs VTM comparison. Most of the DMCs were found in introns followed by intergenic, promoter, and exonic regions. Among these DMCs, 60% (479) were hypermethylated and 40% (315) were hypomethylated, potentially regulating 739 nearby genes (FDR < 0.1). Biological processes over-represented by these genes included transport of ions through voltage gated channels (KCNK13, KCNT1, CACNA1B, KCNK9, LRRC55, KCNAB2, CACNA1S, KCNJ2, CACNG5, CLIC5, TPCN2, KCNQ1), which may be associated to pregnancy establishment by inducing pregnancy-associated relaxation and uterine artery dilatation. Some genes associated with structural development were also regulated by VTM supplementation (i.e., TIAM1, COL18A1, DYSF, BMP10, RXRA, EHMT1, COL4A2, PLEC, ZFAT, MTMR2, NAV1, ANHX, ACACB, and LIMK2). Collectively, these results suggest that periconceptual maternal vitamin and mineral supplementation affects the methylation pattern and potentially regulates the expression of genes involved in fetal liver development and ion transport.

PSV-3 Effects of maternal early gestational weight gain on multigenerational skeletal muscle gene regulation in offspring

Abstract Maternal nutrition during the periconceptional period may have multigenerational effects on the gene regulation of fetal skeletal muscle. This study aimed to investigate the impact of maternal rate of body weight gain (F0) during early gestation on the differential gene expression in the skeletal muscle of newborn (F1) and second-generation fetuses (F2) female offspring. To this end, crossbred Angus heifers (F0) were assigned to either a low gain (LG; 0.28 kg/d; n = 8) or moderate gain (MG; 0.79 kg/d; n = 8) group during the first 84 d of gestation. Subsequently, heifers (F0) were managed as a single group on a forage-based diet until the weaning of the F1 offspring (8 mo). The F1 heifers were estrus synchronized and bred via AI at 15 mo, and F2 fetuses were harvested on d 84 of gestation. Longissimus dorsi muscle was collected at birth (F1) and the 84-d harvest in F1 heifers and their F2 fetuses for multigenerational RNA-Seq analysis. Differentially expressed genes (DEGs) were identified using the DESeq2 R-package. Significant genes were retrieved based on P - value ≤ 0.05 and log2 fold change|0.5|. We previously reported that F1 heifers from MG dams at birth were ~2 kg heavier (P < 0.03), and herein we report the impact on the gene regulation of skeletal muscle in the F1 and F2 generations. At birth, F1 heifers from MG cows exhibited 275 DEGs, of which 98 were downregulated, and 177 genes were upregulated, related to the immune system (TNFAIP3, TLR5), cellular signaling and transduction (RASGRP2, NFE2), and extracellular matrix (TGM3, MMP17). Changes in gene expression persisted in F1 heifers through development, breeding, and until the evaluation at d 84 of gestation. At this time point, we identified 75 upregulated genes out of 177 DEGs. These genes were underlying cellular functions (USP43, PASK), hematopoiesis (THPO), metabolism, and enzymatic activity (SMOX, OAT) as possible metabolic adaptations. Similarly, 102 genes were downregulated, mainly associated with immune and inflammatory response (CHI3L1, LDAF1). Regarding the F2 fetuses, 151 DEGs were differentially expressed. Among them, 63 were upregulated in the MG group and involved with biological functions such as ion channels and transport (KCNAB1, SLC9A3), transcriptional regulation, and signaling (ZNF75D, TMEM106B, DPP6), enzymatic activity, and metabolism (B3GNT4, FAM20A, ALDH5A1, and PRSS23). Likewise, 88 downregulated genes were associated with the cell cycle and proliferation (APOOL, CIR1, and STIL). In conclusion, periconceptional maternal nutrition aimed at moderate weight gains can have multigenerational effects on the gene regulation of fetal muscle tissue.

Ion Dynamics at the Intermediate Charging State of the Sodium Vanadium Fluorophosphate Cathode.

Na super ionic conductor (NASICON)-type polyanionic vanadium fluorophosphate Na3V2O2(PO4)2F (NVOPF) is a promising cathode material for high-energy sodium-ion batteries. The dynamic diffusion and exchange of sodium ions in the lattice of NVOPF are crucial for its electrochemical performance. However, standard characterizations are mostly focused on the as-synthesized material without cycling, which is different from the actual battery operation conditions. In this work, we investigated the hopping processes of sodium in NVOPF at the intermediate charging state with 23Na solid-state nuclear magnetic resonance (ssNMR) and density functional theory (DFT) calculations. Our experimental characterizations revealed six distinct sodium coordination sites in the intermediate structure and determined the exchange rates among these sites at variable temperatures. The theoretical calculations showed that these dynamic processes correspond to different ion transport pathways in the crystalline lattice. Our combined experimental and theoretical study uncovered the underlying mechanisms of the ion transport in cycled NVOPF and these understandings may help the optimization of cathode materials for sodium-ion batteries.

A Cu/MnOx Composite with Copper-Doping-Induced Oxygen Vacancies as a Cathode for Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries are anticipated to be the next generation of important energy storage devices to replace lithium-ion batteries due to the ongoing use of lithium resources and the safety hazards associated with organic electrolytes in lithium-ion batteries. Manganese-based compounds, including MnOx materials, have prominent places among the many zinc-ion battery cathode materials. Additionally, Cu doping can cause the creation of an oxygen vacancy, which increases the material's internal electric field and enhances cycle stability. MnOx also has great cyclic stability and promotes ion transport. At a current density of 0.2 A g-1, the Cu/MnOx nanocomposite obtained a high specific capacitance of 304.4 mAh g-1. In addition, Cu/MnOx nanocomposites showed A high specific capacity of 198.9 mAh g-1 after 1000 cycles at a current density of 0.5 A g-1. Therefore, Cu/MnOx nanocomposites are expected to be a strong contender for the next generation of zinc-ion battery cathode materials in high energy density storage systems.

Negative Differential Resistance in Conical Nanopore Iontronic Memristors.

Emerging ion transport dynamics with memory effects at nanoscale solution-substrate interfaces offers a unique opportunity to overcome the bottlenecks in traditional computational architectures, trade-offs in selectivity and throughput in separation, and electrochemical energy conversions. Negative differential resistance (NDR), a decrease in conductance with increasing potential, constitutes a new function from the perspective of time-dependent instead of steady-state nanoscale electrokinetic ion transport but remains unexplored in ionotronics to develop higher-order complexity and advanced capabilities. Herein, NDR is introduced in hysteretic and rectified ion transport through single conical nanopipettes (NPs) as ionic memristors. Deterministic and chaotic behaviors are controlled via an electric field as the sole stimulus. The NDR arises fundamentally from the availability and redistribution of the ionic charges during the hysteretic and rectified transport at asymmetric nanointerfaces. The elucidated mechanism is generalizable, and the drastically simplified operations enable tunable state-switching dynamics with higher-order complexity besides the first-order synaptic functions in multiple excitatory and inhibitory states.

Differential Impact of Surface Conduction and Electroosmotic Flow on Ion Transport Enhancement by Microscale Auxiliary Structures.

Our research investigates the impact of auxiliary structures on ion transport in electrochemical systems such as batteries and microscale desalination units, whose importance for sustainable development has increased dramatically in recent decades. The electrochemical systems typically feature ion-selective surfaces, such as electrodes and ion exchange membranes, where ion depletion can cause performance issues including metal dendrite formation and flow instability. Recent research has shown that auxiliary structures in these electrochemical systems can enhance ion transfer near ion-selective surfaces, thereby resolving the instability problem and improving the energy conversion efficiency of the system. Our study leverages recent advancements in nanoscale electrokinetics to model these auxiliary structures as pillar arrays near an ion exchange membrane in a microchannel. We examine how these structures enhance ion transports relative to the characteristic length scale of microchannel depth and pillars' proximity to the ion-selective surface. Results show that the effect of the pillars varies significantly with their placement. Specifically, in deeper microchannels, where electrokinetic convection is stronger, the closer the auxiliary structure is to the ion-selective membrane, the better the ion transfer. However, in the thinner microchannel, the proximity of the auxiliary structure to the ion selective membrane has a less significant correlation with the ion transfer. Therefore, this finding highlights the importance of spatial arrangement of the auxiliary structures in improving the performance of electrochemical devices. Conclusively, this study can help to better understand energy conversion systems such as fuel cells, salinity gradient power generation systems, and electrochemical desalination systems, where auxiliary structures can be used in the vicinity of ion-selective surfaces. Especially, our fundamental electrokinetic study provides an effective means for designing the efficient electrochemical platforms utilizing micro/nanofluidics.

Water, Salt, and Ion Transport and Its Response to Water-Saving Irrigation in the Hetao Irrigation District Based on the SWAT-Salt Model

Soil salinization is one of the main hazards affecting the sustainable development of agriculture in the Hetao Irrigation District (HID) of Inner Mongolia. To grasp the water and salt transport patterns and spatial–temporal distribution characteristics of the HID at the regional scale, the improved Soil and Water Assessment Tool with a salinity module (SWAT-Salt) model was used to establish the distributed water and salt transport model for the watershed in this study. The results demonstrated that the modified model could more accurately represent the process of water and salt changes in the HID. The coefficient of determination (R2) in the simulation of streamflow and discharge salt loading was 0.83 and 0.86, respectively, and the Nash–Sutcliffe efficiency (NSE) was 0.80 and 0.74, respectively. Based on this, different hydrological processes (surface runoff, lateral flow, groundwater, soil seepage) as well as spatial–temporal distribution characteristics of water salinity in groundwater and soil were analyzed in the HID. Differences in groundwater and soil salinity in different land uses and soil types were also compared. Of these, surface runoff and lateral flow salt discharge loading are concentrated in the southwestern portion of the basin, while groundwater salt discharge loading is concentrated in the eastern as well as southwestern portions of the basin. The salt discharge loading from groundwater accounts for about 98.7% of the total salt discharge loading from all hydrological pathways and is the major contributing part of salt discharge from the irrigation area. Soil salinity increases gradually from west to east. Groundwater salinity (2946 mg/L) and soil water electrical conductivity (0.309 dS/m) were minimized in the cropland. Meanwhile, rational allocation of irrigation water can appropriately increase the amount of salt discharge loading. In conclusion, the model could provide a reference for the investigation of soil salinization and water–salt management measures in irrigation areas.

Engineering Interconnected Nanofluidic Channel in a Hydrogel Supernetwork toward K+ Ion Accelerating Transport and Efficient Sensing.

Ion transportation via the mixed mechanisms of hydrogels underpins ultrafast biological signal transmission in nature, and its application to the rapid and sensitive sensing detection of human specific ions is of great interest for the field of medical science. However, current research efforts are still unable to achieve transmission results that are comparable to those of bioelectric signals. Herein, 3D interconnected nanochannels based on poly(pyrrole-co-dopamine)/poly(vinyl alcohol) (P(Py-co-DA)/PVA) supernetwork conductive hydrogels are designed and fabricated as stimuli-responsive structures for K+ ions. Distinct from conventional configurations, which exhibit rapid electron transfer and permeability to biosubstrates, interconnected nanofluidic nanochannels collaborated with the P(Py-co-DA) conductive polymer in the supernetwork conductive hydrogel significantly improve conductivity (88.3 mS/cm), ion transport time (0.1 s), and ion sensitivity (74.6 mV/dec). The faster ion response time is attributed to the synergism of excellent conductivity originating from the P(Py-co-DA) polymer and the electronic effect in the interconnected nanofluidic channels. Furthermore, the supernetwork conductive hydrogel demonstrates K+ ion selectivity relative to other cations in biofluids such as Na+, Mg2+, and Ca2+. The DFT calculation indicates that the small solvation energy and low chemical transfer resistance are the main reasons for the excellent K+ ion selectivity. Finite element analysis (FEA) simulations further support these experimental results. Consequently, the P(Py-co-DA)/PVA supernetwork conductive hydrogels enriched with the 3D interconnected nanofluidic channels developed in this work possess excellent sensing of K+ ions. This strategy provides great insight into efficient ion sensing in traditional biomedical sensing that has not been explored by previous researchers.

Hydrated Calcium Vanadate Nanoribbons with a Stable Structure and Fast Ion Diffusion as a Cathode for Quasi-Solid-State Zinc-Ion Batteries.

We demonstrated the use of hydrated calcium vanadate (CaV6O16·3H2O, denoted as CaVO-2) as a cathode for aqueous zinc-ion batteries (AZIBs). Nanoribbons of hydrated calcium vanadate facilitated shortening of the Zn2+ transport distance and accelerated zinc-ion insertion. The introduction of interlayer structure water increased the interlayer spacing of calcium vanadate and as a "lubricant". Ca2+ insertion also expanded the interlayer spacing and further stabilized the interlayer structure of vanadium-based oxide. The density functional theory results showed that the introduction of Ca2+ and structured water could effectively improve the diffusion kinetics, resulting in the rapid transport of zinc ions. As a result, AZIBs based on the CaVO-2 cathode offered high specific capacity (329.6 mAh g-1 at 200 mA g-1) and fast charge/discharge capability (147 mAh g-1 at 10 A g-1). Impressively, quasi-solid-state zinc-ion batteries based on the CaVO-2 cathode and polyacrylamide-cellulose nanofiber hydrogel electrolytes maintained an outstanding specific capacity and long cycle life (162 mAh g-1 over 10 000 cycles at 5 A g-1). This study provided a reliable strategy for metal-ion insertion and the structural water introduction of oxides to produce a high-quality cathode for ZIBs. Meanwhile, it provides ideas for the combination of vanadium-based materials and gel electrolytes to construct solid-state zinc-ion batteries.

Drosophila Nhe2 Over-expression Induces Autophagic Cell Death.

Autophagy is a conserved catabolic process where double membrane-bound structures form around macromolecules or organelles targeted for degradation. Autophagosomes fuse with lysosomes to facilitate degradation and macromolecule recycling for homeostasis or growth in a cell autonomous fashion. In cancer cells, autophagy is often upregulated and helps cancer cells survive nutrient deprivation and stressful growth conditions. Here, we propose that the increased intracellular pH (pHi) common to cancer cells is sufficient to induce autophagic cell death. We previously developed tools to increase pHi in the Drosophila eye via over-expression of DNhe2, resulting in aberrant patterning and reduced tissue size. We examined fly eyes at earlier stages of development and found fewer interommatidial cells. We next tested whether this decrease in cell number was due to increased cell death. We found that the DNhe2-induced cell death was caspase-independent, which is inconsistent with apoptosis. However, this cell death required autophagy genes, which supports autophagy as the mode of cell death. We also found that expression of molecular markers supports increased autophagy. Together, our findings suggest new roles for ion transport proteins in regulating conserved, critical developmental processes and provide evidence for new paradigms in growth control.

Synergistic Cathode Design for High-Performance Dual-Salt Magnesium/Lithium-Ion Batteries Using 2D/2D 1T/2H-MoS2@Ti3C2Tx MXene Nanocomposite.

Magnesium-ion batteries (MIBs) and dual-salt magnesium/lithium-ion batteries (MLIBs) have emerged as promising contenders for next-generation energy storage. In contrast to lithium metal anode in lithium metal batteries, magnesium metal anode in MIBs and MLIBs presents a safer alternative due to the limited dendrite growth and higher volumetric capacity, along with higher natural abundance. This study explores a MLIB configuration with a novel cathode design by employing a 2D/2D nanocomposite of 1T/2H mixed phase MoS2 and delaminated Ti3C2Tx MXene (1T/2H-MoS2@MXene) to address challenges associated with slow kinetics of magnesium ions during cathode interactions. This cathode design takes advantage of the high electrical conductivity of Ti3C2Tx MXene and the expanded interlayer spacing with enhanced conductivity of the 1T metallic phase in 1T/2H mixed phase MoS2. Through a designed synthesis method, the resulting nanocomposite cathode maintains structural integrity, enabling the stable and reversible storage of dual Mg2+ and Li+ ions. The nanocomposite cathode demonstrates superior performance in MLIBs compared to individual components (253 mAh g-1 at 50 mA g-1, and 36% of capacity retention at 1,000 mA g-1), showcasing short ion transport paths and fast ion storage kinetics. This work represents a significant advancement in cathode material design for cost-effective and safeMLIBs.

Discovering new genes for alfalfa (Medicago sativa) growth and biomass resilience in combined salinity and Phoma medicaginis infection through GWAS

Salinity and Phoma medicaginis infection represent significant challenges for alfalfa cultivation in South Africa, Europe, Australia, and, particularly, Tunisia. These constraints have a severe impact on both yield and quality. The primary aim of this study was to establish the genetic basis of traits associated with biomass and growth of 129 Medicago sativa genotypes through genome-wide association studies (GWAS) under combined salt and P. medicaginis infection stresses. The results of the analysis of variance (ANOVA) indicated that the variation in these traits could be primarily attributed to genotype effects. Among the test genotypes, the length of the main stem, the number of ramifications, the number of chlorotic leaves, and the aerial fresh weight exhibited the most significant variation. The broad-sense heritability (H²) was relatively high for most of the assessed traits, primarily due to genetic factors. Cluster analysis, applied to morpho-physiological traits under the combined stresses, revealed three major groups of accessions. Subsequently, a GWAS analysis was conducted to validate significant associations between 54,866 SNP-filtered single-nucleotide polymorphisms (SNPs) and seven traits. The study identified 27 SNPs that were significantly associated with the following traits: number of healthy leaves (two SNPs), number of chlorotic leaves (five SNPs), number of infected necrotic leaves (three SNPs), aerial fresh weight (six SNPs), aerial dry weight (nine SNPs), number of ramifications (one SNP), and length of the main stem (one SNP). Some of these markers are related to the ionic transporters, cell membrane rigidity (related to salinity tolerance), and the NBS_LRR gene family (associated with disease resistance). These findings underscore the potential for selecting alfalfa genotypes with tolerance to the combined constraints of salinity and P. medicaginis infection.

One-step hydrothermal synthesis of vanadium dioxide/carbon core–shell composite with improved ammonium ion storage for aqueous ammonium-ion battery

Aqueous nonmetallic ion batteries have garnered significant interest due to their cost-effectiveness, environmental sustainability, and inherent safety features. Specifically, ammonium ion (NH4+) as a charge carrier has garnered more and more attention recently. However, one of the persistent challenges is enhancing the electrochemical properties of vanadium dioxide (VO2) with a tunnel structure, which serves as a highly efficient NH4+ (de)intercalation host material. Herein, a novel architecture, wherein carbon-coated VO2 nanobelts (VO2@C) with a core–shell structure are engineered to augment NH4+ storage capabilities of VO2. In detail, VO2@C is synthesized via the glucose reduction of vanadium pentoxide under hydrothermal conditions. Experimental results manifest that the introduction of the carbon layer on VO2 nanobelts can enhance mass transfer, ion transport and electrochemical kinetics, thereby culminating in the improved NH4+ storage efficiency. VO2@C core–shell composite exhibits a remarkable specific capacity of ∼300 mAh/g at 0.1 A/g, which is superior to that of VO2 (∼238 mAh/g) and various other electrode materials used for NH4+ storage. The NH4+ storage mechanism can be elucidated by the reversible NH4+ (de)intercalation within the tunnel of VO2, facilitated by the dynamic formation and dissociation of hydrogen bonds. Furthermore, when integrated into a full battery with polyaniline (PANI) cathode, the VO2@C//PANI full battery demonstrates robust electrochemical performances, including a specific capacity of ∼185 mAh·g−1 at 0.2 A·g−1, remarkable durability of 93 % retention after 1500 cycles, as well as high energy density of 58 Wh·kg−1 at 5354 W·kg−1. This work provides a pioneering approach to design and explore composite materials for efficient NH4+ storage, offering significant implications for future battery technology enhancements.