Ion Flux Research Articles

Diurnal humidity cycle driven selective ion transport across clustered polycation membrane

The ability to manipulate the flux of ions across membranes is a key aspect of diverse sectors including water desalination, blood ion monitoring, purification, electrochemical energy conversion and storage. Here we illustrate the potential of using daily changes in environmental humidity as a continuous driving force for generating selective ion flux. Specifically, self-assembled membranes featuring channels composed of polycation clusters are sandwiched between two layers of ionic liquids. One ionic liquid layer is kept isolated from the ambient air, whereas the other is exposed directly to the environment. When in contact with ambient air, the device showcases its capacity to spontaneously produce ion current, with promising power density. This result stems from the moisture content difference of ionic liquid layers across the membrane caused by the ongoing process of moisture absorption/desorption, which instigates selective transmembrane ion flux. Cation flux across the polycation clusters is greatly inhibited because of intensified charge repulsion. However, anions transport across polycation clusters is amplified. Our research underscores the potential of daily cycling humidity as a reliable energy source to trigger ion current and convert it into electrical current.

Graphene Field‐Effect Transistors for Sensing Ion‐Channel Coupled Receptors: Toward Biohybrid Nanoelectronics for Chemical Detection

AbstractGraphene field effect transistors (G‐FETs) have appeared as suitable candidates for sensing charges and have thus attracted large interest for ion and chemical detections. In particular, their high sensitivity, chemical robustness, transparency, and bendability offer a unique combination for interfacing living and soft matters. Here demonstrated their ability to sense targeted biomolecules is demonstrated, by combining them with ion channel‐coupled receptors (ICCRs). These receptors are naturally or artificially expressed within living cell membranes to generate ion fluxes in the presence of chemicals of interest. Here, those biosensors are successfully combined with a G‐FET array which converts the bio‐activation of the ICCRs into readable electronic signals. This hybrid bioelectronic device leverages the advantages of the biological receptor and the graphene field effect transistor enabling the selective detection of biomolecules, which is a current shortcoming of electronic sensors. Additionally, the G‐FET allows for discrimination of the polarity of the ion fluxes which otherwise remains hidden from conventional electrophysiological recordings. The multisite recording ability offered by the G‐FET array raises numerous possibilities for multiscale sensing and high throughput screening of cellular solutions or analytes, which is of both fundamental and applied interest in health and environment monitoring.

Multi-physics modeling of tungsten collector probe samples during the WEST C4 He campaign

We describe the results of a multi-scale, multi-physics modeling assessment of SOLPS-ITER, hPIC2, RustBCA and Xolotl, in which five single-crystal tungsten (W) samples were placed in a reciprocating collector probe and exposed to helium (He) plasma in the WEST fusion device. In our models, we considered a pure (100 %) He plasma, as well as one with oxygen (O) present (95% He 5% O) corresponding to the impurity concentration estimated during the C4 He campaign in WEST. Our SOLPS simulations approximately match experimental reciprocating Langmuir probe plasma measurements of plasma density and temperature. Using these plasma parameters as input, hPIC2 and RustBCA predict that the presence of oxygen impurities lead to a 15%–20% decrease in ion and heat fluxes to the surface, and an order of magnitude higher sputtering yields (compared with a pure He plasma). Xolotl predictions for the response of tungsten to plasma surface interactions (PSIs) agree with experimental LAMS analysis, and indicate large near-surface He concentrations, which quickly decay with depth. Our model also shows an increasing role of erosion—in removing the near-surface He—with time. Overall, slightly higher retention is predicted for tungsten exposed to a pure He plasma, with the largest differences in the near-surface gas content caused by the large oxygen-induced erosion. This highlights the important role that impurities play in PSI. Therefore, future work will focus on providing a fully self-consistent description of oxygen (and oxides, etc.) in our models, through multi-species implementation in GITR and inclusion of oxygen and tungsten oxide formation in Xolotl.

Ionic conductivity and hydrogen permeability of microporous polysulfone membranes grafted by acrylic acid

Energy losses and purity of product gases in alkaline water electrolysis strongly depend on properties of a separator positioned between the electrodes. This paper reports on heterogeneous separators based on microporous polysulfone membranes modified by graft co-polymerization of acrylic acid. After neutralization with KOH, the pores of the modified membranes were filled with potassium polyacrylate, a superabsorbent material forming hydrogel upon intake of an aqueous electrolyte. Under electrolysis conditions of 50 °C and atmospheric pressure, increasing amount of hydrogel in pores suppresses hydrogen permeability without apparent reduction of ionic conductivity. We have identified the product of ionic resistance and hydrogen flux as a suitable parameter to compare performance of separators of various thickness. In terms of this parameter, present separators surpass the performance of Zirfon™ Perl UTP 500 tested under the identical conditions. Ex-situ aging test in 30 wt% KOH at 60 °C has revealed preservation of high wettability for up to 1340 h.

Promoted Stability and Reaction Kinetics in Ni-Rich Cathodes via Mechanical Fusing Multifunctional LiZr2(PO4)3 Nanocrystals for High Mass Loading All-Solid-State Lithium Batteries.

Sulfide all-solid-state lithium battery (ASSLB) with nickel-rich layered oxide as the cathode is promising for next-generation energy storage system. However, the Li+ transport dynamic and stability in ASSLB are hindered by the structural mismatches and the instabilities especially at the oxide cathode/sulfide solid electrolyte (SE) interface. In this work, we have demonstrated a simple and highly effective solid-state mechanofusion method (1500 rpm for 10 min) to combine lithium conductive NASICON-type LiZr2(PO4)3 nanocrystals (∼20 nm) uniformly and compactly onto the surface of the single crystallized LiNi0.8Co0.1Mn0.1O2, which can also attractively achieve Zr4+ doping in NCM811 and oxygen vacancies in the LZPO coating without solvent and annealing. Benefiting from the alleviated interface mismatches, sufficient Li+ ion flux through the LZPO coating, promoted structural stabilities for both NCM811 and sulfide SE, strong electronic coupling effect between the LZPO and NCM811, and enlarged (003) d-spacing with enriched Li+ migration channels in NCM811, the obtained LZPO-NCM811 exhibits superior stability (185 mAh/g at 0.1C for 200 cycles) and rate performance (105 mAh/g at 1C for 1300 cycles) with high mass loading of 27 mgNCM/cm2 in sulfide ASSLB. Even with a pronounced 54 mgNCM/cm2, LZPO-NCM811 manifests a high areal capacity of 9.85 mAh/cm2. The convenient and highly effective interface engineering strategy paves the way to large-scale production of various coated cathode materials with synergistic effects for high performance ASSLBs.

Silicon weakens the outer apoplastic barrier in roots of rice and delays its formation, resulting in increased Na+ and Cl− fluxes to the shoot

In rice, silicon can mitigate abiotic and biotic stresses. We therefore investigated the effect of Si on key root traits related to soil flooding and salinity tolerance with emphasis on the outer apoplastic barrier and cortical aerenchyma. We tested the hypothesis that Si application alters the phenotypic response of these root traits by growing rice in nutrient solutions without or with Si, designed to mimic drained or flooded soils. We measured the barrier strength through resistance to O2 and water of the outer parts of adventitious roots along with cortical aerenchyma and other root structural traits. We found that Si delayed the barrier formation and caused lower amounts of inducible cortical aerenchyma. The delay in barrier formation resulted in higher xylem loading of Na+ and Cl-, i.e., the sap flux of both ions was significantly higher for plants with access to Si. The increased ion fluxes correlated with lower lignin and suberin deposition in the outer part of the root. Consequently, we do not recommend using Si application to alleviate combined stress of salinity and soil flooding in rice, since the barrier was more permeable to O2, and the aerenchyma formation was less pronounced in roots with Si.

Aequorin-Based In Vivo Luminescence Imaging Detects Calcium Signalling in Response to Biotic and Abiotic Stresses in Tomato

The tomato (Solanum lycopersicum L.), a widely cultivated and economically important vegetable crop, is subject to a number of biotic and abiotic stresses in nature. Several abiotic and biotic stresses have been demonstrated to elevate the concentration of cytosolic free Ca2+ ([Ca2+]i) in Arabidopsis due to the influx of calcium ions. In this study, recombinant aequorin was introduced into the tomato in order to investigate the change in [Ca2+]i when treated with exogenous Ca2+. This resulted in strong luminescence signals, which were mainly observed in the roots. Luminescence signals were also detected in the whole plant, including the leaves, when a surfactant (Silwet L-77) was added to coelenterazine. The concentration of [Ca2+]i increased with the dosage of NaCl/elf18. The luminescence signals also showed a lower increase in intensity with elf18 treatment compared to NaCl treatment. Furthermore, the [Ca2+]i responses to other abiotic or biotic stresses, such as H2O2 and Pep1, were also evaluated. It was found that this transgenic tomato expressing aequorin can effectively detect changes in [Ca2+]i levels. The transgenic tomato expressing aequorin represents an effective tool for detecting changes in [Ca2+]i and provides a solid basis for investigating the adaptation mechanisms of tomatoes to various abiotic and biotic stresses. Moreover, the aequorin-based system would be a highly valuable tool for studying the specificity and crosstalk of plant signalling networks under abiotic and biotic stresses in tomatoes.

Biomarkers and Endophenotypes of Post-traumatic Headaches.

To review existing literature on biomarkers for post-traumatic headache (PTH). Preclinical models and clinical findings have started to elucidate the biology that underlies PTH. Traumatic brain injury results in ionic flux, glutamatergic surge, and activation of the trigeminal cervical complex resulting in the release of pain neuropeptides. These neuropeptides, including calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP), play a key role in the pathophysiology of migraine and other primary headache disorders. Only two studies were identified that evaluated CGRP levels in PTH. Neither study found a consistent relationship between CGRP levels and PTH. One study did discover that nerve growth factor (NGF) was elevated in subjects with PTH. There is no conclusive evidence for reliable blood-based biomarkers for PTH. Limitations in assays, collection technique, and time since injury must be taken into account. There are multiple ideal candidates that have yet to be explored.

Encapsulation of photosensitizer worsen cell responses after photodynamic therapy protocol and polymer micelles act as biomodulators on their own

Photodynamic therapy (PDT) is a photochemical therapeutic modality used clinically for dermatological, ophthalmological and oncological applications. Pheo a was used as a model photosensitizer, either in its free form or encapsulated within poly(ethylene oxide)-block-poly(ε-caprolactone) (PEO-PCL) polymer micelles. Block copolymer micelles are water-soluble biocompatible nanocontainers with great potential for delivering hydrophobic drugs. Empty PEO-PCL micelles were also tested throughout the experiments. The goal was to conduct an in vitro investigation into human colorectal tumor HCT-116 cellular responses induced by free and encapsulated Pheo a in terms of cell architecture, plasma membrane exchanges, mitochondrial function, and metabolic disturbances. In a calibrated PDT protocol, encapsulation enhanced Pheo a penetration (flow cytometry, confocal microscopy) and cell death (Prestoblue assay), causing massive changes to cell morphology (SEM) and cytoskeleton organization (confocal), mitochondrial dysfunction and loss of integrity (TEM), rapid and massive ion fluxes across the plasma membrane (ICP-OES, ion chromatography), and metabolic alterations, including increased levels of amino acids and choline derivatives (1H NMR). The detailed investigation provides insights into the multifaceted effects of encapsulated Pheo-PDT, emphasizing the importance of considering both the photosensitizer and its delivery system in understanding therapeutic outcomes. The study also raises questions as to the broader impact of empty nanovectors per se, and encourages a more comprehensive exploration of their biological effects.

Modulating the zinc ion flux and electric field intensity by multifunctional metal-organic complex interface layer for highly stable Zn anode

The uncontrollable growth of Zn dendrites accompanied by side reactions severely impedes the industrialized process of zinc ion electrochemical energy storage devices. Herein, we propose a practical metal-organic complex interface layer to manipulate the zinc ion flux and electric field intensity, enabling highly homogeneous zinc electrodeposition. The zinc-terephthalic acid complex (ZnPTA) with lower adsorption energy for zinc ion (−1.3 eV) builds a zincophilic interface favoring the ordered nucleation and growth of Zn. Moreover, the ZnPTA layer can serve as physical barrier to protect the newly deposited Zn from corrosion in the aqueous electrolyte. The modified Zn anode with the ZnPTA layer (ZnPTA@Zn) demonstrates excellent cycling stability more than 3000 h at 1 mA/cm2. Besides, the zinc-ion battery and zinc-ion hybrid capacitor using the ZnPTA@Zn electrode deliver outstanding cycle performance (up to 5500 cycles with high residual capacity ratio of 77.9%). This work provides a promising metal-organic complex interface design on enhancing the performance of Zn metal anode.

Effect of TTYH3 on cholangiocarcinoma invasion, metastasis and lymph node metastasis through Wnt/β-catenin pathway.

57 Background: Cholangiocarcinoma is a malignant tumor originating from the bile duct epithelium. Metastasis is an important factor affecting the prognosis of cholangiocarcinoma. To explore the role and mechanism of calcium-activated chloride channel protein Tweety homolog 3 (TTYH3) in cholangiocarcinoma metastasis. Methods: TTYH3 was overexpressed and knocked down in cholangiocarcinoma cells, and in vitro experiments were performed to clarify the biological function of TTYH3 in cholangiocarcinoma. Experiments on xenograft tumor mice model have shown that TTYH3 promotes tumorigenesis of cholangiocarcinoma cells. Analysis of the relationship between TTYH3 expression and patient prognosis and lymph node metastasis in cholangiocarcinoma tissue specimens. Exosomes were extracted from bile of patients with cholangiocarcinoma and bile duct stones, and the expression of TTYH3 in exosomes was compared. TTYH3 overexpressed exosomes were used to treat endothelial cells, and their function and mechanism in promoting lymphangiogenesis were analyzed. Results: In vitro experiments confirmed that TTYH3 promoted the migration and invasion of cholangiocarcinoma cell line QBC939. In vivo experiments confirmed that TTYH3 promotes the tumorigenesis of cholangiocarcinoma cells. TTYH3 promotes epithelial-to-mesenchymal transition of cholangiocarcinoma cells through the Wnt/β-catenin signaling pathway. TTYH3 promotes cholangiocarcinoma cell self-expression through positive feedback. TTYH3 is highly expressed in cholangiocarcinoma tissues. Patients with high TTYH3 expression have poor prognosis and a high incidence of lymph node metastasis. The TTYH3 protein content of bile exosomes in patients with cholangiocarcinoma is increased, which promotes the invasion and metastasis of cholangiocarcinoma cells, while also promoting lymphangiogenesis and increased permeability. TTYH3 promotes the uptake of exosomes by lymphatic cells and promotes lymphangiogenesis by regulating the influx of calcium ions and chloride ions in lymphatic cells. Conclusions: TTYH3 promotes the invasion and metastasis of cholangiocarcinoma cells through the Wnt/β-catenin signaling pathway, and exosome TTYH3 promotes lymphangiogenesis and lymph node metastasis.

A synthetic method to assay polycystin channel biophysics.

Ion channels are biological transistors that control ionic flux across cell membranes to regulate electrical transmission and signal transduction. They are found in all biological membranes and their conductive state kinetics are frequently disrupted in human diseases. Organelle ion channels are among the most resistant to functional and pharmacological interrogation. Traditional channel protein reconstitution methods rely upon exogenous expression and/or purification from endogenous cellular sources which are frequently contaminated by resident ionophores. Here we describe a fully synthetic method to assay functional properties of polycystin channels that natively traffic to primary cilia and endoplasmic reticulum organelles. Using this method, we characterize their oligomeric assembly, membrane integration, orientation and conductance while comparing these results to their endogenous channel properties. Outcomes define a novel synthetic approach that can be applied broadly to investigate channels resistant to biophysical analysis and pharmacological characterization.

Tunable Cytosolic Chloride Indicators for Real-Time Chloride Imaging in Live Cells.

Chloride plays a crucial role in various cellular functions, and its level is regulated by a variety of chloride transporters and channels. However, to date, we still lack the capability to image instantaneous ion flux through chloride channels at single-cell level. Here, we developed a series of cell-permeable, pH-independent, chloride-sensitive fluorophores for real-time cytosolic chloride imaging, which we call CytoCl dyes. We demonstrated the ability of CytoCl dyes to monitor cytosolic chloride and used it to uncover the rapid changes and transient events of halide flux, which cannot be captured by steady-state imaging. Finally, we successfully imaged the proton-activated chloride channel-mediated ion flux at single-cell level, which is, to our knowledge, the first real-time imaging of ion flux through a chloride channel in unmodified cells. By enabling the imaging of single-cell level ion influx through chloride channels and transporters, CytoCl dyes can expand our understanding of ion flux dynamics, which is critical for characterization and modulator screening of these membrane proteins. A conjugable version of CytoCl dyes was also developed for its customization across different applications.

(Invited) Electrolyte Engineering for Disruptive Cost Reduction of Electrolyzer: Hydrogen Generation from Dense Carbonate Buffer Solution

Water electrolysis using renewable electricity is a key process for generating green hydrogen, a crucial element in the pursuit of a sustainable society. To make substantial strides in lowering the cost of green hydrogen, it is imperative to address not only the expense of the electricity involved but also the cost associated with the electrolyzer itself [1]. The current challenge lies in the materials chosen for electrolyzers operating under extreme acidic or alkaline conditions, which necessitate the use of costly corrosion-resistant components. A viable solution involves considering non-extreme pH water as an electrolyte, allowing for the utilization of affordable and readily available materials, such as iron or stainless steel, in key electrolyzer components like the frame or bipolar plate [2]. Despite the reported inferior performance of non-extreme pH electrolysis compared to extreme pH conditions, primarily due to inevitable pH shifts (resulting in concentration overpotential) and elevated solution resistance, advancements in technology and research hold the potential to overcome these challenges.Our research group has been actively engaged in the exploration of electrolyte engineering, a concept centered on optimizing the diffusion flux of buffer ions to mitigate the previously mentioned challenges in non-extreme pH conditions [3,4]. Our approach involves leveraging a dense buffer solution to maximize the flux of buffer ions, resulting in a significant reduction in concentration overpotential. This strategy becomes even more impactful when the operating temperature is elevated to the commercially viable range of 80-100 °C [5]. The synergistic effect of employing a dense buffer solution, combined with elevated temperatures, proves to be a promising avenue for advancing electrolyte engineering and optimizing the performance of electrolysis systems in non-extreme pH conditions. In this presentation, we will delve into our discoveries concerning non-noble metal electrocatalysts, specifically focusing on their efficacy in both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER).Our research has led us to identify transition metal-based electrocatalysts that demonstrate exceptional efficiency in catalyzing OER within a carbonate buffer electrolyte at near-neutral pH [6]. Among the diverse materials we explored, the iron-nickel composite, coupled with copper or gold on electrochemically activated Ni (ECA-Ni) substrates [7], stands out as a superior performance. Notably, these electrodes exhibited a remarkable OER catalysis rate of 1 A cm−2 and an overpotential of approximately 330 mV, becoming competitive with highly alkaline counterpart.Next, our research has uncovered noteworthy electrocatalysts based on copper and molybdenum, demonstrating exceptional efficiency in catalyzing the hydrogen evolution reaction (HER) within a carbonate buffer electrolyte at pH 10.5 [8]. The most promising sample achieved a current density of 1 A cm−2 at an overpotential of approximately 0.2 V, a performance comparable to previously reported HER results in highly alkaline conditions. Detailed characterization of these electrocatalysts unveiled that the addition of copper resulted in a rougher surface structure, contributing to the largest double-layer capacitance. These characteristics are indicative of an enlarged active surface area, which is pivotal for enhanced catalytic activity. Furthermore, the introduction of copper element correlated with a decreased apparent Tafel slope, suggesting a tailored nature of the active sites. These insights not only shed light on the structural modifications induced by copper but also underscore its role in optimizing the electrocatalytic performance.Finally, we integrated the previously developed HER and OER catalysts with a carefully selected polyether sulfone (PES) diaphragm [8]. This strategic combination resulted in a notable enhancement of overall cell performance within a 3.0 mol kg− 1 K-carbonate solution at pH 10.5 and a temperature of 353 K. The resultant cell performance, factoring in the series resistance, achieved a 1 A cm− 2 at a voltage of approximately 2.0 V. This achievement stands competitively against the top-class commercial alkaline electrolyzers. These findings not only highlight the feasibility of non-extreme pH electrochemical electrolyzers in industrial applications but also underscore the potential for further advancements and optimizations. The demonstrated success serves as a compelling indicator of the viability of our approach and opens avenues for refining non-extreme pH electrolysis for even greater efficiency and applicability in industrial settings.Reference[1] M. Chatenet, et al., Chem. Soc. Rev. 2022, 51, 4583.[2] M. Pourbaix, “Atlas of Electrochemical Equilibria in Aqueous solutions”, 1974.[3] T. Shinagawa and K. Takanabe, ChemSusChem 2017, 10, 1318.[4] T. Shinagawa et al., ChemCatChem 2019, 11, 5961.[5] T. Naito, et al., ChemSusChem 2022, 8, e202102294.[6] T. Nishimoto, et al., ChemSusChem 2022, e202201808.[7] T. Shinagawa, et al., Angew. Chem. Int. Ed. 2017, 56, 5061.[8] T. Nishimoto, et al., ACS Catal. 2023, 13, 14725.

Understanding Electrochemical and Mechanical Durability of Bipolar Membranes Used in Electrodialysis

Using renewable energy to drive direct carbon capture systems is a powerful way to contribute to net negative emissions. When using liquid alkaline sorbents for CO2 direct air capture, it is critical to reduce the energy demand for CO2 concentration and sorbent regeneration. Electrodialysis is an ideal candidate technology to integrate renewable energy into this process, however, to enable this ion-exchange membrane separators that can operate at high ion flux and low voltage are needed. Bipolar membranes (BPMs), that generate protons and hydroxide ions from the dissociation of water when operated in reverse bias, are the enabling component to generate acid and base in electrodialysis systems. Bipolar membrane electrodialysis (BPMED) uses a BPM to create acidifying and basifying chambers which are well suited to concentrate and release CO2 and concentrate the remaining alkaline effluent to cycle back to the capture process. Current BPM durability, however, sufferers at high current density (ion flux) and physical scale. BPMs have several known degradation mechanisms including chemical breakdown of ion exchange polymers, loss of junction adhesion, or physical breakdown due to shearing force and pressure swings in an electrodialysis cell.To assess the electrochemical and mechanical durability of BPMs under operational conditions, we investigated how fabrication conditions (including preconditioning, hot pressing, and catalyst loading) impact the adhesion of custom made BPMs. T-peel studies were performed ex-situ to quantify adhesive forces of BPMs made of different compositions and prepared under different conditions, and BPMED experiments were performed to assess the electrochemical performance of the corresponding BPMs. The BPMED results show that, while adhesion is necessary to physically maintain the BPM junction, mechanical adhesion alone cannot overcome poor ion and water transport management at the water dissociation junction. The results of this systematic comparison indicate that in order for BPMs to operate at high current densities, high adhesion forces made during fabrication of BPMs will need to be balanced with water dissociation kinetics and ion/water transport through the individual membrane layers.

Enhancing Reversibility and Stability of Mg Metal Anodes: High-Exposure (002) Facets and Nanosheet Arrays for Superior Mg Plating/Stripping.

Magnesium metal batteries (MMBs), recognized as promising contenders for post-lithium battery technologies, face challenges such as uneven magnesium (Mg) plating and stripping behaviors, leading to uncontrollable dendrite growth and irreversible structural damage. Herein, we have developed a Mg foil featuring prominently exposed (002) facets and an architecture of nanosheet arrays (termed (002)-Mg), created through a one-step acid etching method. Specifically, the prominent exposure of Mg (002) facets, known for their inherently low surface and adsorption energies with Mg atoms, not only facilitates smooth nucleation and dense deposition but also significantly mitigates side reactions on the Mg anode. Moreover, the nanosheet arrays on the surface evenly distribute the electric field and Mg ion flux, enhancing Mg ion transfer kinetics. As a result, the fabricated (002)-Mg electrodes exhibit unprecedented long-cycle performance, lasting over 6000 h (>8 months) at a current density of 3 mA cm-2 for a capacity of 3 mAh cm-2. Furthermore, the corresponding pouch cells equipped with various electrolytes and cathodes demonstrate remarkable capacity and cycling stability, highlighting the superior electrochemical compatibility of the (002)-Mg electrode. This study provides new insights into the advancement of durable MMBs by modifying the crystal structure and morphology of Mg.

Enhancing the Performance of Electrochemical RAM (ECRAM) through Modeling Guided Device Engineering

Traditionally, the only ions allowed or welcomed by the microelectronic industry are those that act as fixed dopants. The issue of mobile ions became welcome primarily due to the memristor technology however, thin film transistor technologies benefit from them too. The electrochemical (transistor) random access memory (ECRAM) is emerging as a promising building block for multi-level neuromorphic computing. Using FAB-compatible materials we construct the ECRAM using CuOx as the gate and ions source (Cu+). The morphology of the HfOx gate insulator layer is tuned to render it ion transporting such that it can act as a uniform electrolyte layer. Lastly, the channel material is WOx with tungsten metal as the source/drain contact.While there are several reports of ECRAM devices, the operation mechanisms are not fully known/understood thus withholding progress of this field. Using the Sentaurus device simulator by Synopsis, including the hydrogen diffusion module, we simulate the mixed ionic electronic operation of the device. We have recently reported that by fitting the simulation to the device performance, we could identify the potentiation mechanism (i.e., insulator charging) and the occurrence of copper plating that takes place under high Cu+ ion flux (as in fast charging of Li batteries).[1]In the first part of the talk, we will expand on the chemical-physics details of the ECRAM device mentioned above. Next, we will present a new device architecture where we remove the WOx layer and study the ionic-electronic conduction of a modified HfOx layer. By fine-tuning the stoichiometry of the HfOx layer, it assumes both roles of ionic electrolyte and electronic conducting channel. Following detailed modelling of the measured properties, we introduce AlO2 as an ionic barrier layer at the WOx/HfOx interface to enhance the ionic retention of the HfOx layer. Using the above three device architectures in conjunction with the mixed ionic-electronic device simulation we reveal the role of the two memory mechanisms: a) Electric field-activated ion transport and b) Structure-induced trapping by ion-barrier layers.Reference[1] Nir Tessler, Nayeon Kim, Heebum Kang, Jiyong Woo; Switching mechanisms of CMOS-compatible ECRAM transistors—Electrolyte charging and ion plating. J. Appl. Phys. 21 August 2023; 134 (7): 074501. https://doi.org/10.1063/5.0154153 Figure 1

Enhancing Reversibility and Stability of Mg Metal Anodes: High‐Exposure (002) Facets and Nanosheet Arrays for Superior Mg Plating/Stripping

AbstractMagnesium metal batteries (MMBs), recognized as promising contenders for post‐lithium battery technologies, face challenges such as uneven magnesium (Mg) plating and stripping behaviors, leading to uncontrollable dendrite growth and irreversible structural damage. Herein, we have developed a Mg foil featuring prominently exposed (002) facets and an architecture of nanosheet arrays (termed (002)‐Mg), created through a one‐step acid etching method. Specifically, the prominent exposure of Mg (002) facets, known for their inherently low surface and adsorption energies with Mg atoms, not only facilitates smooth nucleation and dense deposition but also significantly mitigates side reactions on the Mg anode. Moreover, the nanosheet arrays on the surface evenly distribute the electric field and Mg ion flux, enhancing Mg ion transfer kinetics. As a result, the fabricated (002)‐Mg electrodes exhibit unprecedented long‐cycle performance, lasting over 6000 h (>8 months) at a current density of 3 mA cm−2 for a capacity of 3 mAh cm−2. Furthermore, the corresponding pouch cells equipped with various electrolytes and cathodes demonstrate remarkable capacity and cycling stability, highlighting the superior electrochemical compatibility of the (002)‐Mg electrode. This study provides new insights into the advancement of durable MMBs by modifying the crystal structure and morphology of Mg.

Electrochemical Recovery of Biomolecules in Redox-Mediated Electrodialysis Platform

In the chemical and biochemical manufacturing industry, the recovery and purification of organic species are amongst the most energy-demanding steps, due to the complexity of product streams, involving unreacted reactants, byproducts, inorganic salts along with the final products.1, 2 Membrane-integrated electrochemical methods have garnered interest as promising candidates for selective recovery of organic molecules, such as whey protein from cheese whey waste.3 Nonetheless, they still encounter a bottleneck in discriminating among charged species, primarily due to the lack of intrinsic ion selectivity on the ion-exchange membrane.1, 4 Here, we demonstrate a layer-by-layer (LBL) functionalization method to control the membrane selectivity, enabling the recovery of organic acids from a multicomponent mixture within a redox-mediated electrodialysis platform. Tailoring the physicochemical properties of ion-exchange membranes through LBL approach enables complete retention of succinate, while enhancing the overall flux for inorganic ions.1 This remarkable retention capability of the LBL membrane extends to mono- (pyruvate) and multivalent organic acids (succinate and citrate), highlighting the robustness of LBL membrane in recovering various organic species, regardless of their charges. Integration of functionalized membrane into the redox-mediated ED system facilitates the continuous enrichment of succinate with high energy efficiency and membrane stability compared to conventional electrodialysis system. Furthermore, we demonstrate continuous up-concentration of succinate in tandem with the partitioning of unreacted sugar and inorganic ions, paving the way for modular multicomponent separations in biomanufacturing processes.

Ions Selectively Intrigued Ionologic Devices for Logic Operation

Capacitive analogues of semiconductor diodes (CAPodes) present a new avenue for energy-efficient and nature-inspired next-generation computing devices. Here, we disclose the generalized concept for bias-direction-adjustable n- and p-CAPodes based on selective ion sieving. Controllable-unidirectional ion flux is realized by blocking electrolyte ions from entering sub-nanometer pores. The resulting CAPodes exhibit charge-storage characteristics with a high rectification ratio (96.29 %). The enhancement of capacitance is attributed to the high surface area and porosity of an omnisorbing carbon as counter electrode. Furthermore, we demonstrate the use of an integrated device in a logic gate circuit architecture to implement logic operations (‘OR’, ‘AND’). This work demonstrates CAPodes as a generalized concept to achieve p-n and n-p analogue junctions based on selective ion electrosorption, provides a comprehensive understanding and highlights applications of ion-based diodes in ionologic architectures. Figure 1