Electrolyte Layer Research Articles

Production and Performance Evaluation of a Novel Ionic Electroactive Polymer Actuator With Ag/RGO Electrodes

ABSTRACTOver the past 15 years, graphene (also known as reduced graphene oxide, RGO) with metal nanoparticle hybrid structures has garnered significant attention as a promising electrode material in electroactive polymer (EAP) actuators, owing to its high electrical conductivity, large surface area, and flexibility, which are particularly beneficial for actuators. In this paper, flexible biocompatible actuators were fabricated by hot‐pressing a chitosan/ionic liquid/glycerol electrolyte layer sandwiched between two electrically conductive Ag‐doped RGO electrode layers. The electrical conductivity of Ag/RGO electrodes was measured as 106.4 S/cm. The electrical conductivity values allow effective ion migration. This results in significant bending displacement of the actuator at very low applied voltages (< 4 V). As a result of the bending tests, the maximum output displacement of the Ag/RGO‐CHI/IL actuator prepared by the three‐step reduction method was 3.5 mm. This study highlights the role of the Ag‐doped RGO electrode and chitosan electrolyte combination in improving the electrical performance and actuation response of the actuator to be flexible, lightweight, and cost effective compared to noble metal electrodes.

Coordination‐Induced Plastic Ceramic‐Ether Coupling Electrolyte for High‐Voltage Lithium Metal Batteries

AbstractThe high‐voltage reactivity and flammability of electrolytes remain critical challenges for high‐safety and high‐energy‐density lithium metal batteries (LMBs). Here, a novel ceramic‐ether coupling electrolyte (CCE) is reported, in which a thin liquid layer of the ether electrolyte is immobilized on the particle surface of Li6.4La3Zr1.4Ta0.6O12 (LLZTO) matrix through coordination interactions. With an LLZTO content exceeding 82%, it demonstrates high plasticity, non‐flammability, and a high oxidation voltage threshold above 5.0 V. strong coordination interactions between LLZTO and solvent molecules or anions are revealed, which generate cohesive forces that impart high‐plastic rheological behavior to the LLZTO matrix, ensuring conformal contact at solid/solid interfaces. These interactions also lead to a loose Li+ solvation sheath in the ether electrolyte, which not only accelerates Li+ transport, achieving a high ionic conductivity of 2.7 × 10−4 S cm−1, but also promotes anion decomposition to form an inorganic‐rich cathode electrolyte interphase (CEI). This enables the Li/LiNi0.8Co0.1Mn0.1O2 (NCM811) cells to operate stably at a cut‐off voltage of 4.5 V. This work can open up new insights into the design of electrolytes for high safety and high‐voltage LMBs.

Robust interface and reduced operation pressure enabled by co-rolling dry-process for stable all-solid-state batteries

The dry-process is a sustainable and promising fabrication method for all-solid-state batteries by eliminating solvents. However, a pragmatic fabrication design for thin and robust solid-state electrolyte (SSE) layers has not been established. Herein, we report a dry-process approach that enhances mechanical stability of SSE layers from film fabrication to cell operation. By co-rolling thick SSE and positive electrode feeds, a uniform, thin SSE layer (50 µm) and a high loading positive electrode layer (5 mAh cm−2) with high active material ratio (80 wt%) are simultaneously achieved. This SSE-positive electrode integrated film exhibits enhanced physical properties and cyclability (> 80% retention after 500 cycles) at low stack pressure (2 MPa) compared to the freestanding counterparts, attributed to reinforced and intimate SSE-positive electrode interface constructed during co-rolling process. Additionally, an all-solid-state pouch cell with high stack-level specific energy (310 Wh kg−1) and energy density (805 Wh L−1) operating at 30 °C and 5 MPa is demonstrated.

Determining the controlling factor of the stress corrosion cracking of 2024 aluminum alloy with different heat treatments in thin electrolyte layer environment

Determining the controlling factor of the stress corrosion cracking of 2024 aluminum alloy with different heat treatments in thin electrolyte layer environment

Electronic/Ionic Conductive MoS6-Based Composites for All-Solid-State Lithium Batteries.

The transition metal polysulfide cathodes driven by anion redox show high reversible specific capacity, demonstrating great application potential in all-solid-state lithium batteries (ASSLBs). However, their inferior electron/ion conductivities and large volume expansion are critical challenges. In this work, the MoS6-10%rGO@15%Li7P3S11 cathode material is synthesized and utilized in ASSLBs. The cooperation of reduced graphene oxide (rGO) can significantly mitigate the volume changes of MoS6 during the cycling and enhance electronic conductivity of the cathode from 2.56 × 10-8 S cm-1 for MoS6 to 0.28 S cm-1 for MoS6-10%rGO. Besides, a thin Li7P3S11 solid electrolyte layer is in situ coated on the surface of MoS6-10%rGO, realizing intimate contact. Meanwhile, the ionic conductivity of the MoS6-10%rGO@15%Li7P3S11 composite reaches 8.4 × 10-4 S cm-1, 3 orders of magnitude greater than that of MoS6 with 2.8 × 10-7 S cm-1. The ASSLBs utilizing the MoS6-10%rGO@15%Li7P3S11 cathode deliver an initial discharge specific capacity of 1111.97 mAh g-1 at 0.1 A g-1. Notably, it achieves a reversible ultrahigh energy density of 1750.94 Wh kg-1 based on the active material at the second cycle. Furthermore, the batteries possess superior cycling stability, maintaining a discharge specific capacity of 729.53 mAh g-1 after 500 cycles at 0.5 A g-1. This work provides a high-energy-density active material for ASSLBs.

Highly Conductive and Self‐Healing Polymer‐Silver Nanocomposite Hydrogel‐Based All‐in‐One Stretchable Supercapacitor

Stretchable supercapacitors offer strong potential as energy storage solutions for next‐generation stretchable electronics. However, maintaining stable and durable electrical output under various deformations, such as bending, twisting, and stretching, remains a challenge. This study presents an all‐in‐one stretchable supercapacitor that utilizes a polymer‐silver nanocomposite hydrogel as the unified base for both the electrode and electrolyte layers. Nonstoichiometric nickel oxide nanoparticles are synthesized and integrated into the polymer‐silver nanocomposite hydrogel to form the hydrogel electrode, which exhibits an elongation at break of up to 1711%, an ultimate tensile strength of 250.7 kPa, and an energy at break of 1.65 MJ m−3. The supercapacitor device is constructed by placing the nanocomposite hydrogel electrolyte layer (swollen in a lithium chloride solution) between two hydrogel electrode layers, with an areal capacitance of 6.4 mF cm−2 at 0.5 mA cm−2. The device demonstrates excellent self‐healing capability with self‐healing efficiencies of ≥80% for mechanical properties and 98% for electrochemical performance. These findings provide a promising avenue for next‐generation stretchable energy storage devices.

Electrochemical Characterization and Simulation of Ion Transport in Anion Exchange Membranes for Water Treatment Applications.

This study presents a comprehensive electrochemical characterization and simulation of anion exchange membranes (AEMs) for water treatment applications, focusing on ion transport behavior. Experimental techniques, including chronopotentiometry, current-voltage (I-V) curve measurements, and electrochemical impedance spectroscopy (EIS), were employed to investigate the kinetics and dynamics of ion transport at the membrane interface. The results were validated and further explored through finite element method (FEM) simulations using COMSOL Multiphysics. The study revealed key insights into the role of membrane resistance, ion diffusion, and capacitive effects on overall membrane performance. Parametric analyses of electrolyte layer thickness, bulk solution concentration, and membrane porosity provided guidelines for optimizing membrane design. The findings highlight the importance of considering these factors in enhancing the efficiency and applicability of AEMs in water treatment processes. Future work will focus on refining simulation models and exploring advanced materials to further improve membrane performance.

Strategic Material Design for Highly Reliable QLC 3D V-NAND Using Bypass Resistive Random Access Memory.

To overcome the limitation of conventional flash memory, electrochemical random-access memory (ECRAM)-based bypass memory (bypass RRAM) has been proposed as a potential candidate for V-NAND memory application. While bypass RRAM demonstrates excellent memory characteristics through ion hopping conduction, the key parameters governing multilevel cell (MLC) operation remain unexplored. In this study, we propose design guidelines for bypass RRAM, targeting highly uniform quadruple-level cell (QLC) operation by using quantized oxygen vacancy (Vo) injections. To achieve the uniform QLC operation, we precisely controlled ion migration using material engineering in the bypass RRAM. By leveraging the unique electrical characteristic of the WOx resistive switching (RS) layer, we minimized Vo migration (from WO2.65 to WO2.73), which enabled low-voltage operation (<5 V) and a significant on/off ratio (>106) with a minimal stoichiometry (Δx < 0.08) change. Additionally, key parameters, such as ionic barrier (Ea,ion) in the electrolyte layer and ion diffusivity (Dion) in the RS layer, were identified to achieve both a high on/off ratio and a uniform sensing margin based on MATLAB simulations and experimental results. As a result, optimized parameters led to superior QLC performance, featuring a highly uniform distribution (σ/μ ∼ 0.01) and a uniform sensing margin (ΔG ∼ 4 μS) between each state without read disturbance issues. Finally, we also confirmed that the substantial reduction of the Vo migration at the nanometer scale suggests the potential for extending beyond QLC levels with quantized Vo injection, ensuring highly uniform switching for V-NAND memory.

Confined water distribution in the ionomer within the catalyst layers of polymer electrolyte fuel cells: A small-angle neutron scattering study

Confined water distribution in the ionomer within the catalyst layers of polymer electrolyte fuel cells: A small-angle neutron scattering study

Sandwich-Structured Aqueous Electrolyte with Water-Content Gradient for Enhanced Longevity and Reaction Kinetics in Zinc Metal Batteries.

Conventional low-concentration aqueous electrolytes (AqE) for Zn metal batteries face undesirable parasitic reactions, severely deteriorating thei.r sustainability. Although low-water-content electrolytes have shown promise in mitigating water splitting, their high viscosity and limited ion transport lead to sluggish reaction kinetics. In this work, we propose a water-content gradient electrolyte (GE) by constructing a sandwich-like structure, where two molecular crowding electrolyte (MCE) layers are applied on both electrode surfaces, while a conventional AqE occupies the space in between. The low-water-content MCE effectively suppresses electrode corrosion and dissolution, while the high-water-content AqE improves ionic conductivity. As a result, Zn/Zn symmetric cells utilizing the GE demonstrate exceptional long-term cycling for over 2000 hours at 2 mA cm-2 to 4 mAh cm-2 and over 300 hours at 7.5 mA cm-2 to 15 mAh cm-2. The Zn-vanadium and Zn-manganese full cells in GE also show remarkable longevity, with cycling lives exceeding several thousand cycles at 2 A g-1, and excellent reaction kinetics across varying current densities. Overall, the GE successfully integrates the benefits of both AqE and MCE, leading to enhanced electrode protection without compromising ion transport, thereby offering a new avenue for developing long-lasting aqueous Zn metal batteries.

Near-sensor reservoir computing for Braille recognition via high stability memristors

Converting external physical information into tactile sensations for efficient dynamic processing like human beings is crucial for edge applications such as intelligent prosthetics and robotics. Reservoir computing, a bio-inspired computing paradigm, excels at processing temporal signals and offers advantages like low training costs and easy deployment on edge devices. Many applications have been developed for reservoir computing using physical devices. However, there has been a paucity of research using reservoir computing to simulate the human tactile system. Furthermore, the implementation of a reusable physical reservoir computing system is of significant importance. Herein, we implement a near-sensor physical reservoir computing system for haptic simulation, utilizing a simple peripheral circuit design. The reservoir's high-dimensional, nonlinear, and short-term memory requirements are physically realized by a memristor with an integrated lithium polymer electrolyte and polycrystalline tungsten oxide layer, which exhibits good cycle-to-cycle consistency. As a proof of concept, the system completes the learning and classification tasks for Braille numerals and characters, achieving a high recognition accuracy of up to 96% within 400 cycles. This approach offers innovative insights for developing human–machine interaction applications with enhanced intelligent perception capability.

An electrochromic alginate fiber based on a W18O49/PEDOT:PSS composite layer.

An electrochromic alginate fiber based on a W18O49/PEDOT:PSS composite layer.

A self-assembly capsule-like solvation structure electrolyte for lithium metal batteries

A self-assembly capsule-like solvation structure electrolyte for lithium metal batteries

Understanding the corrosion evolution of galvanic steel under simulated marine atmospheric environment using real-time EIS measurement

PurposeThe application of galvanized steel is widespread across industries due to its protective zinc coating that protects against atmospheric corrosion. However, previous studies have primarily focused on long-term corrosion rates rather than the full-scale corrosion behavior of the zinc. This paper aims to study the full-scale corrosion evolution of galvanic steel under simulated marine atmospheric environment using real-time EIS measurement.Design/methodology/approachElectrochemical impedance spectroscopy (EIS) provides an advanced method in monitoring such behavior. Therefore, the EIS method has been used to conduct a comprehensive investigation on the corrosion behavior of galvanic steel in a full-time manner.FindingsThe results indicate that the corrosion process of galvanic steel can be divided into three stages: an initial stage with an increased corrosion rate, a subsequent stage with a reduced corrosion rate, and finally a third stage with the lowest and constant corrosion rate. The evolution of corrosion resistance is closely related to changes in composition and structure of the patina layer. In the initial stage, galvanized steel undergoes the formation of soluble ZnCl2 and needle-like Zn5(OH)8Cl2·H2O, which promotes the generation and maintenance of an electrolyte layer, consequently leading to an increase in corrosion rate. With prolonged corrosion time, there is a continuous accumulation of Zn5(OH)8Cl2·H2O within the patina layer, which reduces the content of soluble components and promotes the development of a denser inner layer, thus enhancing corrosion resistance.Originality/valueThis work holds significance in the monitoring of corrosion, understanding the evolution of corrosion and predicting the lifespan of galvanized steel.

Research Progress in Ionic Liquid-Based Electrolytes for Electrochromic Devices.

Electrochromic (EC) technology has become one of the smart technologies with the most potential for development and application at this stage. Based on electrochromic devices (ECDs), this technology has shown extraordinary potential in the fields of smart windows, display devices, and sensing systems. With the optimization and iteration of various core components in ECDs, the electrolyte layer, a key component, evolved from its initial liquid state to a quasi-solid state and solid state. As driven by increasing application demands, the development trend indicates that all-solid-state, transparent electrolytes will likely become the future form of the electrolyte layer. Recently, the application of ionic liquid (IL)-based electrolytes in the field of electrochromism attracted a lot of attention due to their ability to bring outstanding EC cycling stability, thermal stability, and a wider operating voltage range to ECDs, and they are regarded as the new generation of electrolyte materials with the most potential for application. Although compared with conventional electrolytes, IL-based electrolytes have the characteristics of high price, high viscosity, and low conductivity, they are still considered the most promising electrolyte materials for applications. However, so far, there has been a lack of comprehensive analysis reports on "Research progress in ionic liquid-based electrolytes for electrochromic devices" within the EC field. In this article, the research progress of IL-based electrolytes in ECDs will be summarized from three perspectives: liquid, quasi-solid, and solid state. The future development directions of IL-based electrolytes for ECDs are discussed.

Visualization of Local Strain Distributions in All‐Solid‐State Batteries with Silicon Negative Electrodes Using Digital Image Correlation for Operando/In situ Microscopy Images

AbstractInvestigating local strain distributions is essential for developing long‐life all‐solid‐state batteries (ASSBs) because capacity fading primarily results from cracks and contact loss caused by volume changes in electrode active materials during battery operation. Digital image correlation (DIC) analysis can be used to create strain distribution maps from continuous images of materials under applied pressure. In this study, DIC analysis of operando confocal microscopy images of an ASSB cross‐section was conducted to elucidate the mechanical degradation mechanism in ASSBs with Si electrodes exhibiting ~300 % volume change. The Si electrode layer exhibited irreversible strain changes, whereas the solid electrolyte (SE) layer exhibited no significant strain changes. Furthermore, DIC analysis was performed using in situ SEM images focused on the Si electrode layer to investigate detailed strain distribution maps for individual Si particles. Higher strain changes were observed in the vertical direction within the SE layer, which led to cracks forming in relatively large Si particles at the beginning of the lithiation process. Visualizing local strain distribution in the electrode layer through DIC analysis of operando/in situ images is a powerful approach for understanding how and where cracks form.

Ionic association and Wien effect in 2D confined electrolytes.

Recent experimental advances in nanofluidics have allowed to explore ion transport across molecular-scale pores, in particular, for iontronic applications. Two-dimensional nanochannels-in which a single molecular layer of electrolyte is confined between solid walls-constitute a unique platform to investigate fluid and ion transport in extreme confinement, highlighting unconventional transport properties. In this work, we study ionic association in 2D nanochannels, and its consequences on non-linear ionic transport, using both molecular dynamics simulations and analytical theory. We show that under sufficient confinement, ions assemble into pairs or larger clusters in a process analogous to a Kosterlitz-Thouless transition, here modified by the dielectric confinement. We further show that the breaking of pairs results in an electric-field dependent conduction, a mechanism usually known as the second Wien effect. However the 2D nature of the system results in non-universal, temperature-dependent, scaling of the conductivity with electric field, leading to ionic coulomb blockade in some regimes. A 2D generalization of the Onsager theory fully accounts for the non-linear transport. These results suggest ways to exploit electrostatic interactions between ions to build new nanofluidic devices.

Investigation for the Influences of Factors Within the Semi-Additive Process (SAP) on Nanovoid Formation in the Cu-Cu Interface by STEM Analysis

Electroless copper deposition is widely used in the electronics industry. In recent years, electronic components tend to be densified as the performance of electronic devices increases. The densification of electronics components means the decreasing of conductor width and spaces formed as the circuit patterns and reducing the diameter of Blind Via Holes used as an interconnect between the circuit layers within the electronic substrates. If voids exist in reduced diameter BVHs, the reliability of electronics components could decrease. Thus, voids formed in the electrolytic Cu / electroless Cu interface and electroless Cu / inner layer Cu interface and the cause of the formation of voids have been the focus of attention in recent years. Although there are some studies regarding voids formation in the interfaces of electrolytic Cu / electro-less Cu / inner layer Cu for such this reason, factors relating to the formation of nanovoids in the interfaces are not clearly mentioned. Therefore, the purpose of this paper is investigation for various factors that could cause void formation in the interface. Experiments performed on actual substrates consisting of copper foil, electroless copper layer, electrolytic copper layer and glass epoxy resin are very practical and easy to understand. On the other hand, it will be hard to find out the root cause of void formation owing to too complicated processes for production of these substrates. We adopted a special method of experiment to prepare samples in order to investigate the effect of just one factor from many factors. This method will be included in the process for preparing actual substrates for the formation of voids. STEM-EDX was used to confirm whether voids exist in the interface or not and the area of electroless copper layer is identified from EDX Ni-mapping results. AES also was used for analysis on surface of inner layer copper. The TEM lamellae were prepared with FIB. The results obtained from these experiments clarify that the formation of voids was related to the presence of copper oxide on the inner layer copper.

Toward Higher Energy Density All‐Solid‐State Batteries by Production of Freestanding Thin Solid Sulfidic Electrolyte Membranes in a Roll‐to‐Roll Process

AbstractAll‐solid‐state batteries (SSB) show great promise for the advancement of high‐energy batteries. To maximize the energy density, a key research interest lies in the development of ultrathin and highly conductive solid electrolyte (SE) layers. In this work, thin and flexible sulfide solid electrolyte membranes are fabricated and laminated onto a non‐woven fabric using a scalable and solvent‐free, continuous roll‐to‐roll process (DRYtraec). These membranes show significantly improved tensile strength compared to unsupported sheets, which facilitates cell assembly and allows a continuous component production using a single‐step calendering process. By tuning the thickness, densified membranes with thicknesses ranging from 40 to 160 µm are obtained after a compression step. The resulting SE membranes retain a high ionic conductivity (1.6 mS cm−1) at room temperature. An excellent rate capability is demonstrated in a SSB pouch cell with a Li2O–ZrO2‐coated LiNi0.9C0.05Mn0.05O2 cathode, a 55 µm thin SE membrane, and a columnar silicon anode fabricated by a scalable physical vapor deposition process. At stack level, a promising energy density of 673 Wh L−1 (and specific energy of 247 Wh kg−1) is achieved, showcasing the potential for high energy densities by reducing the SE membrane thickness while retaining good mechanical properties.

Insights on proton‐conducting ceramic electrochemical cell fabrication

AbstractThis study investigates the key factors influencing sintering behavior and grain growth in (BCZYYb4411)–NiO negatrodes and BCZYYb electrolytes for protonic ceramic electrochemical cells (PCECs). Elastic net machine learning models are applied to a dataset of nearly 200 individual PCEC button cells fabricated over the course of more than 3 years to identify the key processing parameters that significantly affect negatrode shrinkage and electrolyte grain growth. The shrinkage rate of the BCZYYb4411–NiO negatrode is primarily governed by the solid‐state sintering behavior. Higher sintering temperatures, longer dwell times, and smaller NiO particle size are the primary determinants that lead to greater shrinkage. New or lightly‐used setters and more compact negatrodes are also found to increase shrinkage. Electrolyte grain growth is chiefly controlled by the liquid‐phase sintering of the BCZYYb phase. Increased cerium content on the B‐site leads to the largest enhancement in grain size, followed by increasing maximum sintering temperature. We find that the parameters used to tune the spray deposition of the electrolyte layer are also critical, with wetter and more uniform sprays promoting grain enlargement. Finally, we find that the sintering environment (e.g. presence/absence of sintering neighbors or sacrificial powders and the ambient humidity level) also substantially impacts both shrinkage and grain growth. This work comprehensively analyzes data from nearly 200 PCECs without “success bias,” meaning that poor performers and fabrication failures were included in the analysis. By doing so, the study provides valuable insight into the critical factors controlling shrinkage and grain growth in BCZYYb‐based PCECs. The findings offer foundational guidance for processing optimization that could lead to better repeatability, increased yields, and higher performance.