Electrochemical Performance Research Articles

Electrohydrodynamic Printing Grid-Structured Catalytic Layers with Excellent Bending Resistance for Flexible Al-air Batteries.

The catalytic film of a flexible Al-air battery is generally a brittle film formed by brushing a slurry onto the surface of carbon cloth. Fatigue bending can easily lead to cracking of the catalytic film and shedding of the active material. This study innovatively proposes a novel grid-structured catalytic layer prepared by electrohydrodynamic printing. Experiments have verified that, compared with traditional catalytic films, the grid-structured catalytic layer exhibits excellent bending resistance. After 10 000 fatigue bending cycles, its relative resistance is ≈1/9 that of the traditional catalytic film. The printed grid-structured catalytic layer is applied to a flexible Al-air battery, which maintains a power density retention rate as high as 92% after the same number of bending cycles. Compared to traditional catalytic films, the electrodynamically printed grid-structured catalytic layer proposed in this study demonstrates both excellent electrochemical performance and bending resistance. This advancement holds significant importance for the development and application of flexible metal-air batteries.

Surface Engineering via Rare Earth Oxide Composite Coating to Enhance the High-Voltage Stability of the LiCoO2 Cathode.

The commercial application of high-voltage LiCoO2 (LCO) faces significant challenges due to rapid capacity decay, primarily attributed to an unstable interface and structure at deeply delithiated states. Herein, a unique rare earth oxide composite coating comprising La2O3, Y2O3, and LaYO3 has been prepared to stabilize LCO at high voltage. The synergistic effect between these rare earth oxides significantly reinforces the protective capabilities of the coating, effectively enhancing the interfacial/structural stability of LCO. When tested at 4.6 V, the coated LCO exhibits an excellent capacity retention of 94.4% after 300 cycles at 1 C. Even after an ultralong charge/discharge test of 700 cycles at 2 C, the coated LCO retains 85.2% of its initial specific capacity, which significantly outperforms the uncoated LCO (6.3%). Moreover, the coated LCO shows enhanced cycling performance at a high temperature of 45 °C, owing to the outstanding thermal stability of the La-Y-O composite. Additionally, the superior cycling stability of the coated LCO at 4.7 V, compared to the uncoated LCO, demonstrated the promising potential of the La-Y-O composite coating in improving electrochemical performance of LCO at higher cutoff voltages. These findings highlight an efficacious strategy to enhance the interfacial/structural stability of high-voltage LCO using rare earth oxides.

Producing Activated Biochar from the Reuse of Discarded Coffee Grounds with Enhanced Adsorptive Features Explored Towards the Stripping Voltammetric Sensing of Copper (II)

AbstractThis work aims to allocate coffee grounds waste to the production of biochar from pyrolysis under different temperatures (350 °C and 500 °C), to add value to it. The resulting materials were characterized by immediate, elemental, thermogravimetric analysis, SEM, FT‐IR, XRD and Raman spectroscopy. Additionally, the need to activate the biochar produced for the desired use was evaluated. The obtained biochars were applied in electroanalysis in the manufacture of modified carbon paste electrodes. This choice was made due to the possibility of reaching a high sensitivity towards the determination of Cu2+ ions. The differential pulse adsorptive anodic stripping voltammetry technique was applied to perform the Cu2+ determination and, in this case, several parameters were optimized, including biochar’ percentage, pH of pre‐accumulation step and reduction/stripping step, pre‐accumulation time, potential and time of reduction of adsorbed‐Cu2+. From this, the proposed modified electrode showed a linear voltammetric response towards Cu2+ in the range of 66.1 to 3997.3 ppb, with a limit of detection of 31.8 ppb, in addition to having been satisfactorily applied in the analysis of water samples (recoveries close to 100 %). Thus, demonstrating the potential for reuse of discarded coffee grounds for the preparation of activated biochar with outstanding electrochemical performance.

Zinc cobalt sulfide with carbon (graphene oxide and CNT) based nanocomposite as positive electrode for asymmetric coin cell supercapacitors

Abstract The world dependence on portable electronic devices has increased the demand for high-performance energy storage devices. The use of transition metal sulfides as faradaic electrode materials for electrochemical energy storage is rapidly increasing due to their high energy density. Herein Zinc Cobalt Sulfide (ZCS) with graphene oxide (GO) and carbon nanotubes (CNT) were used to create an interconnected ZCS composite network using a solvothermal technique. The materials were characterized by utilizing XRD, FT-Raman, TGA, FESEM/EDX, XPS, and BET. The electrochemical performance of the materials was examined using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The prepared electrodes exhibited both pseudocapacitor behavior and double-layer capacitor behavior, indicating the hybrid nature. Furthermore, All the electrode ZCS, ZCS/GO, ZCS/CNT, and ZCS/GO/CNT electrodes demonstrated higher capacitance behavior, with values of 420, 551, 585 and 811 F g−1 at 1 A/g. Among these ZCS/GO/CNT electrode exhibits outstanding electrochemical properties, with a notable retention of 81.08% at 10 Ag−1 because Combining ZCS nanoparticles with interconnected GO and CNT provides excellent electronic conductivity and stability. The assembled ZCS/GO/CNT//graphene oxide asymmetric coin cell (ACC) supercapacitor showed a high energy density of 33.3 Wh kg–1 at a power density of 624 W kg–1. The 3D nanostructure of ZCS/GO/CNT/Graphene oxide has great potential for developing foldable energy storage devices.

Correction to: Synergistic enhancement of electrochemical performance in reversible solid oxide cells via deficiency-induced oxygen vacancy and nanoparticle generation

Correction to: Synergistic enhancement of electrochemical performance in reversible solid oxide cells via deficiency-induced oxygen vacancy and nanoparticle generation

Synthesis and Electrochemical Performances of Fluffy Carbonized Hexagonal KCoPO4 as Pseudocapacitive Electrode for High performing Hybrid Supercapacitor Applications

AbstractElectrochemical energy storage is one of the effective ways that can address the mentioned issues as alternative energy/power produced through solar or windmills can effectively be stored for continuous usage. Hybrid/Asymmetric supercapacitors can deliver a significant amount of power density as well as increased energy density with better rate capability and longer lifespan. The fluffy carbonized hexagonal KCoPO4 synthesized via a simple sol‐gel method accompanied by calcination has delivered high capacitance and longer cyclibility as a positive electrode in aqueous asymmetric supercapacitors. The fluffy carbonized hexagonal KCoPO4 exhibited a specific capacitance equal to 725 F/g at 0.5 A/g current density with excellent cyclic stability. The predominant intercalative pseudocapacitive charge storage behavior seems to be the reason behind the high capacitance of the electrode due to the active involvement of Co2+/3+ redox couple mediate charge storage as intercalative (inner) and capacitive, (outer) surface charges storage on the electrode were close to 37 % and 63 % respectively. Aqueous Asymmetric supercapacitor mode with KCoPO4 being a positive electrode and activated carbon being a negative electrode (KCoPO4//AC) was designed to address its performance in 2 M KOH aqueous electrolyte. The fabricated device in AASc mode (AC//KCoPO4) achieved the highest energy density close to 121.1 Wh/kg with a high power density of 6945 W/kg in the potential window of 1.5 V in 2 M KOH electrolyte.

Chitosan/Nitrogen-doped graphene nanocomposite for supercapacitor application

Abstract In this study, we explore the chitosan/nitrogen-doped graphene oxide (CS-NGO) nanocomposite using the hydrothermal method and incorporate it onto carbon paper by a deep coating technique for supercapacitor applications. The incorporation of CS-NGO, a non-toxic and environmentally friendly material, significantly enhances the electrochemical performance. The electrochemical properties are explored by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and impedance spectrum (EIS). The analyses reveal a specific capacitance increase from 2.84 μF cm−2 to 3.96 μF cm−2, a reduction in charge transfer resistance (Rct) from 24.75 Ω to 16.74 Ω, a decrease in Rs resistance from 4.9 Ω to 0 Ω, and a reduction of equivalent series resistance (ESR) from 12.87 Ω to 6.41 Ω. In addition, the results demonstrate remarkable enhancements in energy density and power density and an excellent cyclic stability of 100% over up to 1000 CV cycles of the CS-NGO electrode. These improvements are due to the potential of CS-NGO nanocomposite in developing high-performance, sustainable supercapacitors with the growing demand for green and safe energy storage solutions. This sign of success in this research is due to the new nanocomposite.

LiTFSI salt concentration effect for well‐balanced ion transport and physical properties in nanocellulose‐reinforced PEO#600 solid electrolytes

AbstractPoly(ethylene oxide) (PEO) with an oxygen group serves as a reactive site for the pathway of lithium‐ion transport. Reducing the PEO crystal domain in solid electrolytes is an extremely efficient approach for enhancing the mobility of ions. The present study applied various EO/Li molar ratios to modify the physical and electrochemical properties of PEO nanocomposite reinforced by nanocellulose. An elevated lithium salt concentration causes a gradual decline in crystallinity and mechanical strength. The electrochemical performance of the 13 EO/Li molar ratio voltammogram and charge–discharge shows efficient Li‐ion transport with 5.6 × 10−4 S/cm conductivity at room temperature and 131 mA h g−1 initial discharge capacity. The shifting glass transition and melting point at lower temperatures (−40.5 to −44.5°C and 45.3–43.8°C) suggest greater ion mobility throughout the large non‐crystalline structure. Lithium ions are limited by membrane weakening and re‐crystallization caused by high lithium salt (EM_11) concentrations. EM_13 has the highest specific capacity, operating voltage, and lithium transfer number depends on balanced electrochemical performance and physical features. XPS surface chemistry analysis explains LiF, Li2CO3, and Li2O solid electrolyte interfaces (SEI) in EM samples. A lower Li2O (11.62 at.%) than LiF (38.4 at.%) after cycling enhances Li‐ion diffusion and cell reversibility.

Using multi‐component carbon composite as current collector in ultra‐battery

AbstractThis study introduces a multi‐component composite as a substitute for lead grids in ultra‐battery structures. The presented composite decreases the weight and simultaneously extends the cycle life of the traditional lead‐acid battery. Overall, UBZCP (the sample containing metal oxides and polyaniline), as the best sample, increases the cyclic stability by 3.3 and 1.4 times under high rate partial state of charge (HRPSoC) mode, compared to Native and UB450 samples. Metal oxides predominantly enhance the electrical conductivity of carbon‐based composites due to catalytic effects in the reduction of graphene oxide during heat treatment. Poly aniline shows considerably positive effect of electrochemical performance due to the high pseudo‐capacitive properties, high interaction of lead ions and the nitrogen in the polymer chains and accordingly hydrogen evolution reaction (HER) inhibition. The synergistic effect of polyaniline and metal oxides makes the best performance in the UBZCP sample achieve. Also, the UBZCP sample represented an enhancement of about 1.21 and 1.39 times in battery life and specific capacity under deep discharge mode compared to the Native sample. As a result, the introduced multi‐component composite making a 3D conductive network, facilitates Pb/PbSO4 reaction reversibility, and reduces the lead sulfate crystal size.

Realizing Dual-Mode Zinc-Ion Storage of Generic Vanadium-Based Cathodes via Organic Molecule Intercalation.

Intercalation engineering is a promising strategy to promote zinc-ion storage of layered cathodes; however, is impeded by the complex fabrication routes and inert electrochemical behaviors of intercalators. Herein, an organic imidazole intercalation strategy is proposed, where V2O5 and NH4V3O8 (NVO) model materials are adopted to verify the feasibility of the imidazole intercalator in improving the zinc storage capabilities of vanadium-based cathodes. The intercalated imidazole molecules could not only expand interlayer spacing and strengthen structural stability by serving as extra "pillars" but also provide extra coordination sites for zinc storage via the coordination reaction between Zn2+ and the C═N group. This gives rise to a dual-mode ion storage mechanism and favorable electrochemical performances. As a result, imidazole-intercalated V2O5 delivers a capacity of 179.9 mAh g-1 after 5000 cycles at 20 A g-1, while the imidazole-intercalated NVO harvests a high capacity output of 170.2 mAh g-1 after 700 cycles at 2 A g-1. This work is anticipated to boost the application potentials of vanadium-based cathodes in aqueous zinc-ion batteries.

Enhancing Vanadium Redox Flow Battery Performance with ZIF-67-Derived Cobalt-Based Electrode Materials

Vanadium redox flow batteries (VRFBs) have emerged as a promising energy storage solution for stabilizing power grids integrated with renewable energy sources. In this study, we synthesized and evaluated a series of zeolitic imidazolate framework-67 (ZIF-67) derivatives as electrode materials for VRFBs, aiming to enhance electrochemical performance. Four materials—Co/NC-700, Co/NC-800, Co3O4-350, and Co3O4-450—were prepared through thermal decomposition under different conditions and coated onto graphite felt (GF) electrodes. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses confirmed the structural integrity and distribution of the active materials. Electrochemical evaluations revealed that electrodes with ZIF-67-derived coatings exhibited significantly lower charge transfer resistance (Rct) and higher energy efficiency (EE) compared to uncoated GF electrodes. Co/NC-800//GF delivered the highest energy efficiency and discharge capacity among the tested configurations, maintaining stable performance over 100 charge–discharge cycles. These results indicate that Co/NC-800 holds great potential for use in VRFBs due to its superior electrochemical activity, stability, and scalability.

Dual Strategies of Na+ Electrolyte Additives and Dendrites Protective Ti3C2TX‐MXene/Zn Anode with 2D MXene Nanosheet Encased Niobium Pyrophosphate (NbP2O7) Composite Binder‐Free Cathode for Stable Zinc‐Ion Storage

AbstractZinc‐ion capacitors (ZICs) are promising next‐generation energy storage systems (ESS) owing to high safety, material abundance, environmental friendliness, and low cost; however, the energy density of ZICs must be improved to compete with lithium‐ion batteries (LIBs). Here, the study implements three strategies to enhance the electrochemical performance and manage dendritic growth on Zn anodes, including crafting a highly efficient redox electroactive niobium pyrophosphate (NbP2O7)/Ti3C2TX‐MXene binder‐free cathode, incorporating a NaClO4 additive electrolyte, and applying a protective Ti3C2TX‐MXene layer on Zn anode. The cathode facilitates rapid Zn2+ ion diffusion and a stable host structure. An electrostatic protection layer formed in additive electrolyte and MXene layers regulates the uniform distribution of the electric fields and supports the equalization of nucleation sites. These results are supported by density functional theory (DFT) calculations. The ZICs display an excellent specific capacitance (113.3 F g−1 at 1.5 A g−1) in aqueous additive electrolytes. The flexible solid‐state ZICs exhibits a volumetric capacitance of 865.05 mF cm−3, and an energy density of 0.347 mWh cm−3 at 2.29 mW cm−3 along with capacitance retention of >100% over 38 000 charge‐discharge cycles.

Triazine-Based Large-Sized Single-Crystalline Two-Dimensional Covalent Organic Framework for High-Performance Lithium-Ion Batteries.

A large-sized single crystalline 2D COFs with excellent crystallinity and stability was prepared through the traditional thermal solvent method. The electrochemical performance can be significantly enhanced using a straightforward hybrid approach that involves in situ growth of the 2D COFs on multi-walled carbon nanotubes (MWCNTs). Both the advantages of COFs and CNTs are mutually enhanced. The single-crystalline feature of the obtained COFs improves the structural integrity and brings excellent chemical and electrochemical stabilities for lithium-ion battery applications. The resultant COF-CNT core-shell hybrids greatly improved the conductivity and demonstrated excellent lithium-ion storage performance with a high capacity of 228 mAh g-1 (0.2 A g-1).

Triazine‐Based Large‐Sized Single‐Crystalline Two‐Dimensional Covalent Organic Framework for High‐Performance Lithium‐Ion Batteries

AbstractA large‐sized single crystalline 2D COFs with excellent crystallinity and stability was prepared through the traditional thermal solvent method. The electrochemical performance can be significantly enhanced using a straightforward hybrid approach that involves in situ growth of the 2D COFs on multi‐walled carbon nanotubes (MWCNTs). Both the advantages of COFs and CNTs are mutually enhanced. The single‐crystalline feature of the obtained COFs improves the structural integrity and brings excellent chemical and electrochemical stabilities for lithium‐ion battery applications. The resultant COF‐CNT core–shell hybrids greatly improved the conductivity and demonstrated excellent lithium‐ion storage performance with a high capacity of 228 mAh g−1 (0.2 A g−1).

Combination Displacement/Intercalation Reaction of Ag0.11V2O5 Cathode Realizes Efficient Manganese Ion Storage Properties.

Aqueous manganese-ion batteries (AMIBs) are becoming more noticeable because of their excellent theoretical capacity, outstanding safety profile, and cost-effectiveness. However, there aren't many studies on cathode materials appropriate for AMIBs, and the manganese-ion storage mechanisms within these materials have not been thoroughly investigated. Furthermore, the electrochemical performance of existing cathode materials remains suboptimal. Here, Ag0.11V2O5 is designed and synthesized as the cathode material and introduces the combination displacement/intercalation reaction mechanism to the manganese ion storage for the first time. Ag0.11V2O5 demonstrates a capacity retention of 90.3% after 1200 cycles at 5 A g⁻¹ and achieves a high rate performance of 100.01 mAh g⁻¹ at 20 A g⁻¹. This impressive electrochemical performance is attributed to the reaction, which provides more Mn2+ storage sites and generates highly conductive Ag within the electrode. This study presents a novel approach to achieving high-capacity AMIBs.

Preparation of high strength and rigidity carbon layer on SiO material surface by dynamic CVD method using gas carbon source C2H2

The main issue in the application of silicon-based negative electrode materials is the inevitable volume expansion, leading to negative electrode material fracture, which severely impacts the performance of batteries. This study employed Chemical Vapor Deposition (CVD) (C2H2@SiO), solid-phase coating method (Pitch@SiO), and liquid-phase coating method (RGFQ@SiO) to coat the surface of SiO materials with a dense amorphous carbon structure. Material property analysis revealed that C2H2@SiO has a relatively small specific surface area (1.8 m2 g−1) and surface carbon increment (2.4 %). It exhibited high reversible specific capacity (1563.4 mAh g−1), high initial Coulombic efficiency (81.45 %), and low volume expansion rate (9.3 %). Mechanical performance testing indicated that the surface carbon layer Young's modulus of C2H2@SiO was the highest (35 GPa), suggesting that using the CVD method to obtain a dense carbon layer can enhance the structural strength of the material. Based on the electrochemical-mechanical coupling theory simulation analysis of the stress during the charge-discharge process of electrode materials, the evolution of concentration and stress field during lithium insertion process was obtained, showing that the coating can further improve the electrochemical and mechanical performance of the negative electrode materials effectively. Additionally, the negative electrode sheets fabricated using sample C2H2@SiO were assembled into 18650 cylindrical batteries, exhibiting excellent cycling performance in 1000 cycles at 25 °C with a capacity retention rate of 85.7 %, along with good rate capability and high/low-temperature performance. The conclusions of this study provide certain guidance for the design and optimization of negative electrode materials for battery electrodes.

Eco-Friendly High Microporosity Low Temperature Plasma Exposed Activated Carbon from Coconut Shell For nano Hybrid Super Capacitors

Abstract This study looked at the structural, chemical, and electrochemical properties of coconut shell activated carbon (CSAC) before and after plasma treatment. Structural analysis using X-ray diffraction (XRD) demonstrated that plasma treatment improves graphitic structure by plans at (002) and (101) for higher angles. Chemical investigation utilizing Fourier-transform infrared spectroscopy (FTIR) revealed an increase in hydroxyl groups and carboxylic content following plasma treatment, which enhances electrochemical performance. Raman spectroscopy revealed a drop in the ID/IG ratio from 1.00 to 0.90, indicating enhanced graphitic order. Scanning electron microscopy (FESEM) showed that plasma treatment improves surface shape, while elemental analysis assessed the high carbon content (76.56% by weight). Contact angle measurements showed a decrease from 114° to 65°, showing improved hydrophilicity after treatment. Electrochemical investigation shows that the plasma-treated CSAC had a maximum specific capacitance of 1612 F/g, compared to 729 F/g for the untreated CSAC, and a total capacitance of plasma treated1685 F/g are untreated 1400 F/g. The cyclic stability tests indicated that the plasma-treated CSAC retained 94% capacitance and 98% coulombic efficiency after 3000 cycles, which is superior to the untreated CSAC's 92% capacitance retention and 95% coulombic efficiency. This reveals that plasma-treated CSAC has significantly improved performance and stability, making it an excellent alternative for high-performance and cost-effective energy storage applications.

An Organic Small Molecule Electrode with Intermolecular Intercalation and Synergistic Effects for High‐Rate Alkali Metal‐Ion Batteries

AbstractDesignable molecular structures, unique ion‐coordination charge storage mechanisms, and resource sustainability enable organic electrode materials to become potential candidates for alkali metal‐ion batteries (AMIBs). Herein, integrating the excellent π–π stacking ability of Hexaazatriphenylene units and strong electron‐withdrawing properties of cyano (C≡N) groups into one moleuce, a π‐conjugated organic compound 1,4,5,8,9,11‐Hexaazatriphenylenehexacarbonitrile (HAT‐CN) is synthesized and systematically investigated as electrodes in Li/Na/K‐ion batteries. Explored by mechanism characterizations and density functional theory calculations, HAT‐CN can provide nine redox‐active sites for Na/K‐ions to intercalate/de‐intercalate, among which six Na/K‐ions are distributed evenly to both sides of conjugated skeletons through intermolecular intercalation and three Na/K‐ions are stored with the synergistic effect of C≡N groups. Employing HAT‐CN as electrodes, AMIBs are found to exhibit high reversible capacities, excellent rate capabilities, and stable cycle performances. After 100 cycles at the current density of 100 mA g−1, Na‐ion batteries present 415.6 mAh g−1 with a capacity fading rate of 1.2% per cycle. Meanwhile, K‐ion batteries maintain 345 mAh g−1 with a coulombic efficiency ≈100%. Li‐ion batteries display superlithiation performances with ultra‐high reversible capacity. This work emphasizes the necessity of comprehensively studying the electrochemical performance of organic electrodes in different secondary battery systems and is conducive to maximizing electrode functionality.

Recent Progress in Liquid Electrolytes for High‐Energy Lithium–Metal Batteries: From Molecular Engineering to Applications

AbstractLithium–metal batteries (LMBs) have garnered significant interests for their promising high gravimetric energy density (Eg) ∼ 750 Wh kg−1. However, the practical application of the LMBs is plagued by the high reactivity and large volume change during charging–discharging of the lithium–metal anode (LMA), seriously deteriorating the battery safety and cycle life. Great efforts have been devoted to tailoring the electrolytes to favor the Li–metal electroplating by uniformizing the deposition morphology and by suppressing the side reactions between electrolytes and LMA. The aggressive chemistries of both the LMA and its high‐voltage counterpart give new electrolyte components more opportunities, especially designing via molecular engineering. Here, a comprehensive and in‐depth overview of the scientific challenges, fundamental mechanisms, and particularly historical strategies of designing new molecules for electrolyte components including solvents, salts, and additives. Their important roles in tuning the Li+ solvation structure, interface composition, decomposition pathways, and the resultant electrochemical performance of LMBs are also presented. Finally, novel insights and promising research directions from the practical application viewpoints are proposed for future electrolyte designs for high‐voltage LMBs.

Unlocking Molecular Interactions of Biredox Eutectic Electrolyte for Non‐Aqueous Symmetrical Organic Redox Flow Batteries

AbstractBiredox deep‐eutectic solvents (DESs)‐based electrolytes have shown unique features in non‐aqueous asymmetrical redox flow batteries (RFBs) that can potentially mitigate the crossover issue. However, strong intermolecular interactions among the electrolyte constituents in DESs bring in practical challenges such as limited mass transfer rates, slow redox kinetics, and degraded cyclability. Here, by using a novel biredox‐type DES based on 4‐methoxy‐2,2,6,6‐tetramethyl‐1‐piperidinyloxy (4‐MeO‐TEMPO) and 3,3′‐dimethylazobenzene (3,3′‐Azo) as a model electrolyte system, the intermolecular interaction involving in the biredox DESs is unlocked by first‐principles calculations, and their influence on the electrochemical performance of biredox DESs couples is systematically investigated in comprehensive consideration of the solvents and the supporting salts. It demonstrates that employing tetrabutylammonium bis‐trifluoromethane sulfonimidate‐acetonitrile as the supporting electrolyte synergistically weakens the intermolecular interactions within the DESs, thereby significantly promoting the redox kinetics and electrochemical reversibility in non‐aqueous symmetrical RBFs. With such an optimized electrolyte, a prototype symmetrical cell under static mode is capable of delivering a high output voltage of ∼2.15 V, a decent cyclability, and the exceptional rate capability with a current density of 25 mA cm−2. This study provides a simple yet effective way to develop advanced RFBs with dependable electrolyte regulation.