Ion Transport Behavior Research Articles

In Situ Copolymerizing ZrO2 with Hydrogel Electrolytes toward High‐Rate and Long‐Life Quasi‐Solid‐State Zn–Ion Batteries

AbstractHydrogel is adopted as a promising alternative electrolyte for the zinc–ion batteries (ZIBs) due to its water‐retaining capacity and high ionic conductivities. However, the high content of free water molecules will affect the operation of electrolytes in ZIBs, resulting in the uncontrolled growth of zinc dendrites and related side reactions. Herein, a functional hydrogel electrolyte is developed by in situ copolymerizing the ceramic ZrO2 with acrylamide and 2‐Acrylamido‐2‐methylpropane sulfonic acid to adjust the ion transport behavior, further improve zinc ions' depositional behavior. The interaction between ZrO2 and ─SO3H groups within the hydrogel is capable of inducing the free migration of zinc ions, resulting in a novel transport pathway, thereby enhancing the diffusion rate of zinc ions with an ionic conductivity of 38.3 mS cm−1. The hydrogen bonding between ceramic particles and free water molecules of the hydrogel electrolyte enables it to achieve stable operation under large current densities (8 mA cm−2, 4 mAh cm−2). Moreover, a full battery with polyaniline (PANI@ZrO2) displays excellent stability (1500 cycles) with a capacity retention rate of 79.2%. The proposed work provides an insightful design of high‐performance electrolyte materials for energy storage by manipulating the zinc behavior.

Scaling Behavior and Conductance Mechanisms of Ion Transport in Atomically Thin Graphene Nano/Subnanopores.

Ion transport through atomically thin nano/subnanopores, such as those in monolayer graphene, presents challenges to traditional ion conduction models, primarily due to extreme confinement effects and hydration interactions. Under these conditions, existing models fail to account for conductance behaviors at the nano- and subnanometer scales. In this study, we perform a combined experimental and theoretical investigation of ion transport in monolayer graphene nano/subnanopores across varying salt concentrations. We introduce a conductance model that accurately predicts the observed scaling behavior by addressing the interaction between counterions and the edges of atomically thin pores, where counterion movement is constrained by the pore's structure. This model also quantifies the hydration energy barrier, highlighting the impact of the hydration shell structures on ion transport efficiency. Our findings reveal that hydrated potassium ions traverse these pores with higher efficiency than previously estimated, offering new insights into ion transport mechanisms under atomic-scale confinement.

Asymmetric ion transport through heterogeneous bilayers of covalent organic frameworks

In recent years, with the development of interfacial polymerization methodologies, the successful preparation of covalent organic framework (COF) monolayers featuring ultrahigh pore density and molecule-scale thickness has become a reality. This advancement has enabled ion transport with ultrahigh flux across extremely short paths. Owing to these processes, the COF monolayers have shown wide potential applications ranging from energy conversion and artificial mechanosensing to ion sieving. To date, nanofluidic systems based on COF monolayers are homogeneous, leading to nearly symmetric ion transport properties. Studies on the ionic transport behavior within ultrathin COF heterojunctions are limited and remain challenging. Herein, using a two-step sequential self-assembly and subsequent interfacial polymerization strategy, bi-layered heterogeneous tetraphenylporphyrin-based COF membranes composed of negatively charged and positively charged monolayers were prepared. Using an electric field as a driving force, rectified ion transport was observed for the first time. Notably, this ionic current rectification property could be modulated by the salt concentration and the structural composition of the membrane, and it was universal for various COF heterojunctions with different chemical ingredients. These findings are beneficial for promoting the development of innovative nanofluidic materials and devices.

Reversed rectification of ionic liquid/water mixtures in conical nanochannels

Because of their remarkable properties, room-temperature ionic liquids (RTILs) are used widely in electrochemistry, fuel cells, supercapacitors, and even DNA sequencing, and many of these applications involve the transport of RTILs in nanoscale media. Particularly for single-molecule detection, the RTIL must be mixed with a solvent (e.g., water) so that the electrolyte has both high viscosity and conductivity to obtain excellent signals. If a RTIL contains a quantity of water in bulk, this has a significant effect on its properties (e.g., the electrochemical window), thereby limiting some applications. However, the physicochemical properties of RTILs containing water in nanoconfined spaces remain unclear, especially their ionic transport behavior. Therefore, reported here is a study of the ionic transport behavior of mixed RTIL/water solutions at the nanoscale using a single conical nanochannel as a nanofluidic platform. The conductivity of the mixtures in the nanoconfined space was closely related to the nanochannel size, and highly diluted mixed solutions resulted in a nonlinear rectification-reversed current, which was possibly due to the adsorption of cations on the nanochannel wall. The maximum rectification ratio was 114, showing excellent rectification that could be used to realize newly conceptualized nanofluidic diodes. In summary, this work provides an exhaustive understanding of the nonlinear ion transport of RTIL/water mixtures and a theoretical foundation for applying RTILs in energy storage and conversion and bio-sensing.

Ultrafast Lithium-Ion Transport Engineered by Nanoconfinement Effect.

Amid the burgeoning demand for electrochemical energy storage and neuromorphic computing, fast ion transport behavior has attracted widespread attention at both fundamental and practical levels. Here, based on the nanoconfined channel of graphene oxide laminar membranes (GOLMs), the lithium ionic conductivity typically exceeding 102 mS cm-1 is realized, one to three orders of magnitude higher than traditional liquid or solid lithium-ion electrolyte. Specifically, the nanoconfined lithium hexafluorophosphate (LiPF6)-ethylene carbonate (EC)/ dimethyl carbonate (DMC) electrolyte demonstrates the ionic conductivity of 170 mS cm-1, outperforming the bulk counterpart by ≈16 fold. At the ultralow temperature of -60°C, the nanoconfined electrolyte also maintains a practically useful conductivity of 11 mS cm-1. Furthermore, the in situ experimental and theoretical framework enables to attribute the enhanced ionic conductivity to the layer-by-layer cations and anions distribution induced by high surface charge and nanoconfinement effects in GO nanochannels. More importantly, integrating such rapid lithium-ion transport nanochannel into the LiFePO4 (LFP) cathode significantly improves the high-rate and long-cycle performance of lithium batteries. These results exhibit the convention-breaking ionic conductivity of nanoconfined electrolytes, inspiring the development of ultrafast ion diffusion pathways based on 2D nanoconfined channels for efficient energy storage applications.

Electrolyte-Gated Ionic Transistor for Highly Sensitive and Selective Iontronic Sensing.

Iontronic sensors based on confined space have garnered significant attention due to their promising applications, ranging from single-cell analysis to in vivo studies. However, their limited sensitivity has constrained their effectiveness in studying molecular information during physiological and pathological processes. Here, we demonstrate an electrolyte-gated ionic transistor (EGIT) by integrating the confined ion transport behavior in a double-barreled micropipet with an electrolyte-gated transistor configuration, achieving highly sensitive and selective sensing. Our EGIT operates at a gate voltage of less than 1 V and can amplify ion current variations by up to 2 orders of magnitude. Both experimental methods and finite element simulations reveal that signal amplification stems from the intensified electric field. Thanks to the easily modified inner surface of the micropipet and the transistor configuration, we develop a highly sensitive and selective iontronic sensing platform for neurochemicals such as ATP, dopamine, and serotonin. More importantly, by utilizing this iontronic sensor, we successfully achieve the detection of trace ATP in rat striatum microdialysate. This study not only expands the scope of transistor technologies but also introduces a novel approach for constructing highly sensitive iontronic sensors, which hold potential applications in biochemical sensing, health monitoring, and disease diagnosis.

The effect of ceramic nanofillers on conductivity and ion-transport behavior in potato starch-based solid bio-polymer electrolyte for advanced energy storage devices

The effect of ceramic nanofillers on conductivity and ion-transport behavior in potato starch-based solid bio-polymer electrolyte for advanced energy storage devices

Bioinspired solid-state nanochannels for molecular analysis.

The acute sensory behaviour in living organisms relies on the highly efficient transport behaviour of ions in biological nanochannels, which has inspired the design and applications of artificial solid-state nanochannels in the field of sensitive analysis. The application of nanochannels for analysis is now widely investigated, and a variety of sensors have been developed. By coupling reliable nanochannel fabrication techniques with a multitude of surface modification strategies, novel sensors with customized sensing capabilities are generated by the integration of recognition elements and nanochannels. The altered physicochemical properties of these solid-state nanochannel sensors will be manifested by steady-state currents when they are affected by the target analyte. In this mini-review, we focus on emerging solid-state nanochannels based on different fabrication processes such as electron-beam etching, anodic oxidation, ion track etching, and self-assembly. Also, modifications of recognition elements are discussed, including nucleic acids, proteins, small molecules, and responsive materials. The key factors of ion transport behaviour during detection are also reviewed, including surface charge, channel size, and wettability. The applications of these bioinspired nanochannels in the exploration of analysis of small molecules (gas molecules, drug molecules and biological molecules) are concisely presented. Furthermore, we discuss the future developments and challenges.

An interactive organic–inorganic composite interface enables fast ion-transport, low self-discharge and stable storage of lithium battery

An interactive organic–inorganic composite interface enables fast ion-transport, low self-discharge and stable storage of lithium battery

Ion Transport and Solution Behavior of Polyanion-Type Li Salts in Nonaqueous Solvents

To achieve fast charging and discharging of Li-ion batteries, it is important to improve the ionic conductivity (σ) of the electrolyte as well as the Li-ion transference number (t Li) [1]. While nonaqueous polyelectrolyte solutions exhibit high Li-ion transference number(t Li = 0.81) upon immobilization of the anion on a polymer backbone, the ionic conductivity (σ = 1.3 mS cm-1) is inferior to that of conventional electrolytes (σ ~10 mS cm-1). One of the reasons for the low ionic conductivity is low dissociation degree caused by the counter-ion condensation on the polymer backbone. To gain an insight into a design strategy of polyelectrolyte-based liquid electrolytes for LIBs, we studied the effects of polyelectrolyte structure and solvent polarity on the transport properties and Li-ion solvation of the polyelectrolytes in carbonate solvents. Here, we employed two polyelectrolyte copolymers with different sequences; random copolymers of the Li salt of a weakly coordinating polyanion, poly[(4-styrenesulfonyl)-(trifluoromethanesulfonyl)amide] (poly(LiSTFSA)) with neutral comonomer unit, and poly[(4-maleimide-N-[(trifluoromethyl)sulfonyl]-benzenesulfonamide lithium salt] (poly(sa-PMI))-based alternating copolymers with neutral comonomer unit. For the random copolymers, the ionic conductivity increased as the ratio of the neutral comonomer increased. This was attributed to the suppression of counter-ion condensation and increased dissociation. The alternating copolymer solution showed higher dissociation than the random copolymers. The highest ionic conductivity was unexpectedly observed for the lowest polar mixture (such as a dimethyl carbonate rich mixture) at the highest salt concentration despite the low dissociation degree of the polyelectrolytes. A unique conduction resulting from the faster diffusion of transiently solvated Li ions along the interconnected aggregates of polyanion chains was suggested in the highly concentrated polyelectrolyte solutions in low polar solvents. A Li/LiFePO4 cell using the polyelectrolyte solution demonstrated a good charge-discharge performance and rate capability[2].

Solvent-Confined Van Der Waals Gap Engineering to Improve Energy Storage in a 2D Layered Supercapacitor

Despite the rapidly growing demand for high-performance and eco-friendly supercapacitors in the pursuit of sustainable energy storage, achieving both high volumetric energy density and ultrafast charging remains a significant challenge. Two-dimensional layered materials (2DLM) have emerged as promising electrode materials due to their ability to form highly networked nanochannels. Understanding the transport behavior of ions within these nanochannels is crucial for efficient energy storage. Recent advancements have shown promise in creating nanochannels that enhance ion transport and storage. However, controlling the properties of nanochannels has been challenging due to their nanoscale size and limited choice of solvents primarily water.Here, we propose a manufacturing method of 2DLM films that confines various solvents within the van der Waals gap, allowing for adjustable thickness from nano to micro dimensions. The confined solvents serve as nanofluidic channels, improving ion transport and achieving high-density energy storage. Our ethanol-confined films demonstrate a gravimetric capacitance of 302 F g-1 and a volumetric capacitance of 1033 F cm-3, measured at a scan rate of 100 mV s-1, which is twice as high as water-confined films. By selectively controlling the nanochannels, we can regulate the channel distance and density of the film, effectively enhancing the electrode surface potential and enabling ultrafast ion transport. This demonstration offers valuable insights into the design of 2DLM films for energy storage and conversion applications.

Highly Efficient Blue Energy Harvesting By Nanoarchitectured Tri-Continuous Porous Structures with Ultrathin Light-Responsive Covalent-Organic Framework Membrane

Designing ion-selective membranes for directly energy harvesting from a salinity gradient between seawater and river water has attracted significant interest. Despite increasing efforts have been made, achieving simultaneously smart ion transport as well as high-performance blue energy output remains largely unexplored. Herein, we report a novel light-responsive ionic diode membrane (TpOMe-Azo/BANM), composed of a branched alumina nanochannel membrane (BANM) and an ultrathin light-responsive TpOMe-Azo covalent-organic framework (COF) layer. The design endows the heterogeneous membrane with tri-continuous porous structures of large-geometry gradient from submicro-scale to sub-3 nm-scale, amplifying diode-like directional ion transport property. The orderly and negatively charged sub-3 nm-scale ion channels in TpOMe-Azo COF makes it highly cation-selective. We demonstrate that the incorporation of the TpOMe-Azo COF endows the membrane with high light-regulated ion transport behavior up to 50% under the UV light irradiation. Benefiting from the merits of high cation-selectivity and ionic diode property, the exploited membrane can produce a high power density of 5.46 W/m2 under the concentration gradient condition of mixing seawater and river water, and even achieves an unprecedented value of up to 7.16 W/m2 under the UV light irradiation. This groundbreaking design of the ionic diode membrane not only marks a substantial advancement in materials science but also delves into novel avenues for light-amplified ion transport utilizing heterogeneous ionic diode membranes. Figure 1

Interface dynamics in electroosmotic flow systems with non-Newtonian fluid frontiers

Abstract Microfluidic applications involving liquid manipulation, selective membranes, and energy harvesting strongly emphasize the importance of the electrokinetic phenomenon, which is widely used at multiple fluid and electrochemical interfaces. However, critical scientific issues that address multifield coupling and multiscale physics have not been well addressed in non-Newtonian fluids. In this paper, electrical field–fluid flow–ion transport coupling is numerically implemented in two mainstream problems, i.e., induced electroconvection phenomena at ion-selective interfaces and induced charge electroosmosis in polarized cylinders. The effects of different non-Newtonian rheological properties, which are absent in Newtonian fluids, on the interfacial dynamics, instability and ion transport are examined. The results reveal that the non-Newtonian rheology significantly modulates the statistical data and interfacial phenomena. Generalized power-law fluids alter velocity and interfacial charge profiles, with shear thinning enhancing ion transport to lower overlimiting current thresholds and shear thickening broadening the limiting current region (with hindered ion transport). In Boger-type Oldroyd-B fluids, the addition of polymer decreases the velocity amplitude and increases the interface resistance. At low voltages, polymer viscoelasticity minimally affects the ohmic and limiting regions, but under convection-dominated flow, different rheological parameters, such as the viscosity ratio, Weissenberg number, anisotropic parameter, and electrohydrodynamic coupling constants, enable controllable regulation of ion transport behavior across a wide range. Finally, this paper states that modulated electroosmosis by complex charged polymers is the future cutting edge. The relevant results supplement the non-Newtonian physics of electrokinetic systems and provide guidance for the design and operation of microfluidic devices.

Poly(bis(1‐methylpiperazin‐1‐ium‐amide) Nanofilm Composite Membrane with Nanochannel‑Enabled Microporous Structure and Enhanced Steric Hindrance for Magnesium/Lithium Separation

AbstractEfficient lithium/magnesium (Li+/Mg2+) separation attainment is fundamental to the extraction of lithium from brine by nanofiltration membrane separation process, which is essential for resource recovery and a circular water economy. However, for poly(piperazine‐amide) nanofilm composite membranes, the higher electronegativity affects the Mg2+ rejection and consequently Li+/Mg2+ separation performance. Manipulating the positive charge density and pore size regulation of the nanofiltration membranes are determinative of the Li+/Mg2+ separation performance improvement. Here, a new monomer 1,1′‐(hexane‐1,6‐diyl)bis(1‐methylpiperazin‐1‐ium) bromide containing bis‐quaternary ammonium cations is employed as a molecular building block to fabricate polyamide nanofilms via interfacial polymerization. The dual quaternary ammoniums and the rod‐shaped conformation of the monomer confer enhanced electropositivity, steric hindrance, loosely packed microporous network structure (pore diameter∼0.8–1.35 nm), and high free volume. The resultant membrane exhibits high water permeance of 28.34 L m−2 h−1 bar−1 with good Li+/Mg2+ selectivity of up to 76.9. In addition, the membrane also exhibits chlorine stability performance owing to the lack of the chlorine sensitive −NH groups in the formed tertiary amide structures. Computational insights on the structural properties, nanofilm formation, and transmembrane water and ion transport behaviors are provided. This study offers insightful theoretical and technological concepts to design and construct membrane materials for energy‐efficient separations.

Manipulation of ionic transport behavior in smart nanochannels by diffuse bipolar soft layer

Soft bipolar nanochannels provide distinct and valuable understanding of the intricate relationship among shape, charge distribution, concentration, and flow dynamics. This study investigates the intriguing realm of nanoscale structures, where two distinct configurations of soft layers with varying charges provide an intricate but appealing setting for the movement and management of ions, as well as the regulation and control of ionic species in nanochannels with five various geometries. It generates cylindrical, trumpet, dumbbell, hourglass, and conical forms. The nanochannels are coated with a diffuse polyelectrolyte layer, and the charge density distribution in the soft layer is described using the soft step distribution function. To enhance accuracy, the impact of ionic partitioning is taken into account. To investigate the effect of soft layer polarity, two types were considered: Type I and Type II. In Type I, the negative pole is at the start, while in Type II, the positive pole is at the start. Thus, Type I features a bipolar soft layer arrangement of negative–positive (NP), whereas Type II has a positive–negative (PN) configuration. The research was conducted under stationary conditions using the finite element method, Poisson–Nernst–Planck, and Navier–Stokes equations. By manipulating variables such as the arrangement order, charge density of the soft layer, and bulk concentration, a numerical analysis was performed to investigate the impact of these variables on current–voltage parameters. The results demonstrate the soft layer with a positive charge serves as a more effective receiver layer for generating greater rectification. For instance, the dumbbell-shaped nanochannel exhibits a rectification of 2046 at a concentration of 1 mM and the lowest charge density in the soft layer. From an alternative perspective, the conductivity in bipolar nanochannels is significantly influenced by the bulk concentration. The study's findings on the fundamental principles of soft bipolar nanochannels have profound implications for the diverse applications of nanochannels. The capacity to regulate and manipulate ion transport through these nanochannels can result in enhanced efficiency, selectivity, and performance in various processes.

Ionic Potential Relaxation Effect in a Hydrogel Enabling Synapse-Like Information Processing.

The next-generation brain-like intelligence based on neuromorphic architectures emphasizes learning the ionic language of the brain, aiming for efficient brain-like computation and seamless human-computer interaction. Ionic neuromorphic devices, with ions serving as information carriers, provide possibilities to achieve this goal. Soft and biocompatible ionic conductive hydrogels are an ideal substrate for constructing ionic neuromorphic devices, but it remains a challenge to modulate the ion transport behavior in hydrogels to mimic neuroelectric signals. Here, we describe an ionic potential relaxation effect in a hydrogel device prepared by sandwiching a layer of polycationic hydrogel (CH) between two layers of neutral hydrogel (NH), allowing this device to simulate various electrical signal patterns observed in biological synapses, including short- and long-term plasticity patterns. Theoretical and experimental results show that the selective permeation and hysteretic diffusion of ions caused by the anion selectivity of the CH layer are responsible for potential relaxation. Such an effect allows us with hydrogels to enable synapse-like information processing functions, including tactile perception, learning, memory, and neuromorphic computing. Additionally, the hydrogel device can operate stably even under 180° bending and 50% tensile strain, expanding the pathway for implementing advanced brain-like intelligent systems.

Porous Organic Cage-Based Quasi-Solid-State Electrolyte with Cavity-Induced Anion-Trapping Effect for Long-Life Lithium Metal Batteries

Porous organic cages (POCs) with permanent porosity and excellent host–guest property hold great potentials in regulating ion transport behavior, yet their feasibility as solid-state electrolytes has never been testified in a practical battery. Herein, we design and fabricate a quasi-solid-state electrolyte (QSSE) based on a POC to enable the stable operation of Li-metal batteries (LMBs). Benefiting from the ordered channels and cavity-induced anion-trapping effect of POC, the resulting POC-based QSSE exhibits a high Li+ transference number of 0.67 and a high ionic conductivity of 1.25 × 10−4 S cm−1 with a low activation energy of 0.17 eV. These allow for homogeneous Li deposition and highly reversible Li plating/stripping for over 2000 h. As a proof of concept, the LMB assembled with POC-based QSSE demonstrates extremely stable cycling performance with 85% capacity retention after 1000 cycles. Therefore, our work demonstrates the practical applicability of POC as SSEs for LMBs and could be extended to other energy-storage systems, such as Na and K batteries.

Illuminating Biomimetic Nanochannels: Unveiling Macroscopic Anticounterfeiting and Photoswitchable Ion Conductivity via Polymer Tailoring.

Artificial photomodulated channels represent a significant advancement toward practical photogated systems because of their remote noncontact stimulation. Ion transport behaviors in artificial photomodulated channels, however, still require further investigation, especially in multiple nanochannels that closely resemble biological structures. Herein, we present the design and development of photoswitchable ion nanochannels inspired by natural channelrhodopsins (ChRs), utilizing photoresponsive polymers grafted anodic aluminum oxide (AAO) membranes. Our approach integrates spiropyran (SP) as photoresponsive molecules into nanochannels through surface-initiated atom transfer radical polymerization (SI-ATRP), creating a responsive system that modulates ionic conductivity and hydrophilicity in response to light stimuli. A key design feature is the reversible ring-opening photoisomerization of spiropyran groups under UV irradiation. This transformation, observable at the molecular level and macroscopically, allows the surface inside the nanochannels to switch between hydrophobic and hydrophilic states, thus efficiently modulating ion transport via changing water wetting behaviors. The patternable and erasable polySP-grafted AAO, based on a controllable and reversible photochromic effect, also shows potential applications in anticounterfeiting. This study pioneers achieving macroscopic anticounterfeiting and photoinduced photoswitching through reversible surface chemistry and expands the application of polymer-grafted structures in multiple nanochannels.

Drying-Wetting Correlation Analysis of Chloride Transport Behavior and Mechanism in Calcium Sulphoaluminate Cement Concrete.

In response to rising CO2 emissions in the cement industry and the growing demand for durable offshore engineering materials, calcium sulphoaluminate (CSA) cement concrete, known for its lower carbon footprint and enhanced corrosion resistance compared to Ordinary Portland Cement (OPC), is increasingly important. However, the chloride transport behavior of CSA concrete in both laboratory and marine environments remains underexplored and controversial. Accordingly, the chloride ion transport behaviors and mechanisms of CSA concrete in laboratory-accelerated drying-wetting cyclic environments using NaCl solution and seawater, as well as in marine tidal environments, were characterized using the rapid chloride test (RCT), X-ray diffraction (XRD), mercury infiltration porosimetry (MIP), and thermogravimetric analysis (TGA). The results reveal that CSA concrete accumulates more chloride ions in NaCl solution than in seawater, with concentrations 2-3.5 times higher at the same water-cement ratio. Microscopic analysis indicates that calcium and sulfate ions present in seawater facilitate the regeneration of ettringite, thereby increasing the density of the surface pore structure. The hydration and repair mechanisms of CSA concrete under laboratory conditions closely resemble those in marine tidal conditions when exposed to seawater. Additionally, this study found that lower chloride ion concentrations and pH levels inhibit the formation of Friedel's salt. Therefore, laboratory experiments with seawater can effectively simulate CSA concrete's chloride transport properties in marine tidal environments, whereas NaCl solution does not accurately reflect actual marine conditions.

Modular Customized Biomimetic Nanofluidic Diode for Tunable Asymmetric Ion Transport.

Artificial ion diodes, inspired by biological ion channels, have made significant contributions to the fields of physics, chemistry, and biology. However, constructing asymmetric sub-nanofluidic membranes that simultaneously meet the requirements of easy fabrication, high ion transport efficiency, and tunable ion transport remains a challenge. Here, a direct and flexible in situ staged host-guest self-assembly strategy is employed to fabricate ion diode membranes capable of achieving zonal regulation. Coupling the interfacial polymerization process with a host-guest assembly strategy, it is possible to easily manipulate the type, order, thickness, and charge density of each module by introducing two oppositely charged modules in stages. This method enables the tuning of ion transport behavior over a wide range salinity, as well as responsive to varying pH levels. To verify the potential of controllable diode membranes for application, two ion diode membranes with different ion selectivity and high charge density are coupled in a reverse electrodialysis device. This resulted in an output power density of 63.7W m-2 at 50-fold NaCl concentration gradient, which is 12 times higher than commercial standards. This approach shows potential for expanding the variety of materials that are appropriate for microelectronic power generation devices, desalination, and biosensing.