Electromotive Research Articles

Novel Differential Protection for a Powerformer Considering Capacitive Current Compensation

A Powerformer is a special type of generator whose peak capacitive current is approximately 30 times larger than that of conventional generators with the same rated apparent power. Powerformer stator fault relays may be misoperated by using conventional differential protection strategies, thus degrading network reliability. Therefore, a novel differential protection scheme for a Powerformer is proposed in this paper. First, the nonlinear distribution laws of the Powerformer stator winding capacitance and induced electromotive force (EMF) are analyzed. Next, an equivalent distributed parameter circuit model of the Powerformer considering cable-windings with graded insulation is established and verified by using FEM-based analysis. Furthermore, to eliminate the influence of the capacitive current on the differential protection, the capacitive current is analyzed, and a novel differential protection scheme considering capacitive current compensation is proposed. A simulation model is established by using MATLAB and PSCAD, and extensive simulation studies verify the effectiveness of the proposed protection approach.

Enhanced Excitation Converter With Parallel/Series DC-Link Based on TAB for DFIG to Improve the LVRT Capability Under Severe Grid Faults

The low-voltage ride-through (LVRT) capability of the doubly-fed induction generator (DFIG) based on the conventional excitation converter is insufficient under severe grid faults. The reason is that the dynamic rotor electromotive forces (EMF) will far exceed the dc-link voltage. To solve this issue, this letter proposes an enhanced excitation converter with parallel/series dc-link based on the triple active bridge (TAB) for DFIG. The dc-link of the enhanced excitation converter consists of the TAB and switching circuit, replacing the capacitive-type dc-link. Based on this topology, the dc-link voltage can increase instantaneously during severe grid faults to resist rotor EMF and improve the LVRT capability of DFIG. Compared with existing LVRT schemes, the enhanced excitation converter enables DFIG to achieve LVRT and inject the reactive current requirements of the grid code into the grid under severe grid faults. Finally, experiments verified the effectiveness of the proposed enhanced excitation converter and its control strategy.

Demagnetization Fault Diagnosis of Permanent Magnet Direct Drive Generator Based on Improved Residual Neural Network

The permanent magnet direct drive wind turbine is the core equipment of the wind turbine. Barrier analysis ensures its safe and reliable operation. The demagnetization failure of the permanent magnet motor will occur because the wind energy equipment works under bad conditions. Taking the permanent magnet direct drive wind turbine as the research object, this paper uses ANSYS simulation software to build a two-dimensional electromagnetic field model of the generator to simulate the uniform demagnetization fault of the permanent magnet direct drive generator to obtain the back electromotive force waveform under different operating conditions and convert the back electromotive force waveform into images as input data for fault diagnosis of the improved residual neural network. Two kinds of materials are used to verify the effect of the diagnosis model, and the simulation results show that both materials can be used for demagnetizing fault diagnosis, which proves the effectiveness of the fault diagnosis strategy.

An Optimized PLL With Time Delay and Harmonic Suppression for Improved Position Estimation Accuracy of PMSM Based on Levenberg–Marquardt

This paper proposes an optimized phase-locked loop (OPLL) based on Levenberg-Marquardt (LM) to improve the estimation accuracy of the sliding mode observer (SMO) based position estimator. The position estimation suffers from dc bias caused by digital control delay, and harmonic caused by inverter nonlinearity and flux spatial harmonics. The OPLL is constructed with two parts to overcome the above negative effects. The delay phase is preliminarily calculated based on linear prediction, so as to compensate for the lag phase in the estimated back electromotive force (back-EMF); secondly, the objective function is built based on the reference and feedback position error, the former contains an unknown harmonic. The objective function can be minimized by the LM to solve for the harmonic amplitude, then the obtained harmonic is used to offset the harmonic components in the estimated position. Wherein, the required partial derivatives of the LM method can be deduced based on the transfer function of PLL and the delay-compensated back-EMF to achieve a stable update of harmonic amplitude. Finally, the corresponding comparative experiments in steady-state and dynamic conditions proved the superiority of the proposed method applied to permanent magnet synchronous motors.

RESEARCH THE EFFECT OF THE FRACTIONAL NUMBER SLOTS OF POLE ON WIND TURBINE GENERATION USING THE ENHANCED SPOTTED HYENA OPTIMIZATION ALGORITHM

The design of machines with permanent magnets is actively developing day by day and is often used in wind energy. The main advantages of such variable speed drives are high efficiency, high power density and torque density. When designing a wind generator with two rotors and permanent magnets, it is necessary to solve such a problem as the correct choice of the number of poles and slots to increase efficiency and minimize the cost of the machine. In this work, an improved spotted hyena optimization algorithm is used to obtain the optimal combination of slots and poles. This optimization algorithm makes it possible to obtain the number of fractional slots per pole and evaluate the operating efficiency of a wind generator with a double rotor and ferrite magnets. At the first stage of machine design, various combinations of slots are installed. Next, the optimal combination is selected from various slot-pole combinations, taking into account the Enhanced Spotted Hyena Optimization (ESHO) algorithm, in which a multi-objective function is configured. Accordingly, the multi-objectives are the integration of reverse electromotive force, output torque, gear torque, flux linkage, torque ripple along with losses. Analysis of the results obtained shows that the proposed algorithm for determining the optimal slot combination is more efficient than other slot combinations. It has also been found that the choice of slot and pole combination is critical to the efficient operation of permanent magnet machines.

Research and development of gas electrode potential oxygen sensors in saturated oxygen liquid LBE

Oxygen sensors play a crucial role in the effective operation of the Active Oxygen Control System (OCS) in liquid LBE systems. In this study, the performance of LSCF/air, LSM/air and Pt/air reference electrode sensors with yttrium stabilized zirconia (YSZ) as the solid electrolyte in the static oxygen saturated liquid lead bismuth eutectic alloy (LBE) was evaluated with varying temperature range by measuring the electromotive force. Compared with the activation temperature of Pt electrode sensor (420 °C), the activation temperature of LSCF electrode and LSM electrode sensor is as low as 320 °C. The LSCF/air and LSM/air sensors show good performance in the high and low temperature tests. However, the electrochemical balance of the Pt/air reference sensor has an irreversible effect at the lowest temperature, leading to the sensor malfunction. During the temperature transient process, the electromotive force (EMF) measured by the sensor shows a deviation from the theoretical value. Besides, the LSCF/air reference sensor has the smallest deviation and the Pt/air reference sensor has the largest deviation. Therefore, the LSCF electrode sensor exhibits best performance in the low operating temperature region.

Comparative Analysis of Consequent-Pole Flux-Switching Machines with Different Permanent Magnet Arrangements for Outer-Rotor In-Wheel Direct-Drive Applications

Recently, the interest in consequent-pole flux-switching permanent magnet (CP-FSPM) machines has been increasing because of the flux-focusing PM arrangements and the removal of the flux-barrier effect. A simple and rigid outer-rotor salient pole rotor structure can be adopted in CP-FSPM machines, making them applicable for in-wheel direct-drive applications. In this study, three CP-FSPM machines with II-shaped (II-PM), V-shaped (V-PM), and straight U-shaped PM (SU-PM) arrays are analyzed and compared. Moreover, a CP-FSPM machine with inclined U-shaped PM (IU-PM) arrays is proposed to improve the flux-focusing effect and stator slot utilization. The working principles of CP-FSPM machines are analyzed by adopting a semi-analytical model. Combining the finite element analysis (FEA) results of air gap flux density and the analytical model of phase back electromotive force (EMF), the contributions of multiple working harmonics to the back EMF are quantitatively analyzed. Additionally, 6/16 and 6/17 CP-FSPM machines with different PM arrangements are globally optimized. Both the no-load and on-load performance of the optimized machines are included in the performance comparison. The results illustrate that the 6/16 and 6/17 machines exhibit their respective merits, and the IU-PM machine shows the best torque production ability in these CP-FSPM machines with the same design criteria.

Spin pumping and inverse spin Hall effect in magnetron-sputtered large area MoS2/Co40Fe40B20 bilayers

Transition metal dichalcogenides (TMDs) are novel class of quantum materials which show potentials for optoelectronics, valleytronics, opto-valleytronics etc. TMDs are also found to exhibit high spin orbit coupling and therefore, they have been extensively studied for spin to charge conversion or spin pumping phenomena. The robustness of MoS2 and its high availability in nature as molybdenite, have made it a suitable candidate for device applications. Among all the methods designed to fabricate large area TMDs on industrially compatible substrates, the sputtering technique offers advantage to prepare large area films. Here we report the observation of spin to charge conversion in large area magnetron-sputtered MoS2 by inverse spin Hall effect (ISHE) via microwave driven ferromagnetic resonance spectroscopy. In the continuous MoS2/CoFeB thin films, angle dependent measurements of ISHE have been performed to identify various galvanometric rectification effects. The spin diffusion length, real part of spin mixing conductance and the electromotive force (emf) arising due to inverse spin Hall effect are found to be 7.83 ± 0.57 nm, (1.43 ± 0.019) × 1019 m−2 and 4.38 ± 0.12 μV, respectively. These results show that the MoS2 films exhibit high spin orbit coupling for spin to charge conversion physics and their relevance in SOT based applications.

Determination of phase equilibria in the CuxZryCr1-ySe2 system by the EMF method

Layered materials ZrSe2, CuZrSe2 and CuCr0.8Zr0.2Se2 were synthesized, and the structure of the obtained compounds was determined. The phase states in CuxZrSe2 and CuxZr0.2Cr0.8Se2 systems were determined by coulometric titration and electromotive force methods. An increase in the potential difference in the electrochemical cells Cu|Cu+|CuxZryCr1-ySe2 upon substituting Zr4+ for Cr3+ (0 < x < 0.5) was also noted. The copper diffusion coefficients for CuZrSe2 and CuCr0.8Zr0.2Se2 were estimated to be 10─9 and 10─10 respectively.

An Improved Full-Speed Domain Sensorless Control Scheme for Permanent Magnet Synchronous Motor Based on Hybrid Position Observer and Disturbance Rejection Optimization

A sensorless control algorithm not only reduces the cost of a permanent magnet synchronous motor (PMSM) system, but also broadens its application scope. Expanding speed threshold and enhancing dynamic performance are crucial aspects. To optimize the adaptability of observers and the immunity of the controller in a full-speed domain, an improved sensorless control scheme for a PMSM based on a hybrid position observer and disturbance compensation is proposed. Firstly, the precise detection of the initial position and the scheme of starting with the load at any position are proposed based on high-frequency rotation injection, magnetic pole direction calibration and square-wave high-frequency injection (HFI). Secondly, a higher-order sliding mode observer (HSMO) is designed to improve high-speed observation performance by introducing an extended electromotive force (EEMF). Correspondingly, a speed controller called PI plus is developed utilizing a reverse control algorithm and the observed disturbance quantity, which further enhances the system’s disturbance rejection capability. Subsequently, a linearly weighted observer switching method and a linear signal withdrawal scheme are proposed to suppress torque and speed oscillations in medium-speed threshold. Furthermore, a normalized linear extended state observer (LESO) is designed to enhance rotor information estimation accuracy and enable the observation of unknown disturbances in full-speed thresholds. Finally, the effectiveness of the proposed sensorless control system is tested through experiments involving variations in speed, load, and parameter. The experimental results indicate that the proposed sensorless strategy is capable of achieving a loaded start. The designed observer switching strategy and the scheme of injection signal withdrawal contribute to a smoother acceleration process. Furthermore, load variation test results at high-speed thresholds demonstrate that the proposed controller can reduce speed drop by 45 rpm compared to a traditional PI. Additionally, the results of parameter variation testing validate the observer’s robustness in the disturbances of ψf within the range of ±0.3 pu.

Properties of “Higher Manganese Silicide-Silicon” Heterostructure

Based on the diffusion technology, many scientists and specialists have conducted research on obtaining materials that are fundamentally different in electrical and photo-thermal parameters from the original material by introducing various input atoms into semiconductor materials and creating deep energy levels in their band gap. The electrical, photoelectric, optical, and magnetic properties of these semiconductor materials have been extensively studied with metal group elements, isovalent elements, and rare earth elements added to silicon through the process of growth, ion implantation, or diffusion from the gaseous state. The technology of introducing impurity atoms into silicon by the diffusion method is distinguished from other methods in its simplicity, energy efficiency, and low cost. Up-to-date, the technology of changing the resistivity and conductivity of the initial sample by diffusion of manganese atoms into single-crystal silicon is studied insufficiently. In the article, it was determined that when manganese atoms diffuse into silicon, a high-manganese silicide is formed on its surface and in the near-surface layer. Based on the analysis of the experimental results, the thermal EMF (electromotive force) in Mn4Si7-Si -&lt;Mn&gt;-Mn4Si7 structures in a certain temperature range and under illumination (with monochromatic or integrated light) is explained by the fact that it based on the Pelte effect, observed in semiconductors.The volt-ampere characteristics (VAC) of the obtained structures were measured at various temperatures, in the dark and in the light. Formation of a boundary layer with high resistivity at the boundary of the higher manganese-silicon transition, the transition from higher manganese silicide to the base of the structure due to the effect of ionization of pores during illumination of structures and external influence. The applied field was clarified based on VAC results. The manganese high silicide layer formed on the silicon surface has the properties of a semiconductor, and the formation of a heterojunction upon transition to silicon is shown on the basis of the sphere diagram.

Improving Instantaneous Angular Speed Monitoring by Means of Sinusoidal EMF Signals Delivered by a Two-Phase n Poles AC Generator Used as a Sensor

Abstract This paper introduces a new approach in instantaneous angular speed monitoring using a two-phase n poles AC generator as sensor. A two-phase n poles (n=50) stepper motor plays the role of sensor. Its rotor is firmly connected to the rotary part whose instantaneous angular speed should be measured. The sensor produces two identical sinusoidal EMF (electromotive force) signals (theoretically shifted with π/2 radians) with the same periods T. This paper proposes to use the mathematical product of the numerical descriptions of these EMF signals in order to define a new EMF signal with a period T/2 whose analysis allows the determination of 4·n=200 samples of instantaneous angular velocity on each full rotation. Each period of this new EMF signal (with an overlap of a semi period) is involved in the description of the instantaneous angular speed. In this way, the sensor is virtually converted in a single-phase 2·n poles (2·n=100) AC generator. The experimental results confirm the validity of this approach.

Development of an Energetic Material Information Self-Destruction Microsystem Based on Bistable Off-On Actuator Composed of Fusible Alloy

The physical self-destruction of an information storage chip (ISC) driven by a detonation wave generated using energetic materials is an important method to ensure the security of key core information. To solve the related problems of high electrostatic sensitivity, poor overcurrent capability, and easy erroneous triggering, a bistable off-on actuator (BO-OA)-based energetic material information self-destruction microsystem is proposed based on a fusible alloy. First, the BO-OA model based on the fusible alloy is constructed. By performing a finite element numerical analysis and experimenting, the response time of the Bi-Sn alloy with a continuous temperature rise from 22°C to 138°C is obtained. Second, a model of the energetic material dose and detonation wave transmission in an air domain is constructed. An analysis using LS-DYNA software indicates that copper azide can produce GPa-level stress waves in a millimeter-level air domain to realize ISC physical self-destruction. Finally, through bulk silicon processing and in situ reaction of the energetic materials, self-destruction module preparation and functional integration are realized. Experiments and simulations show that when driven by a 12 V electromotive force, the BO-OA reaches the fusible alloy melting point of 138°C within 320 μs, and can realize electrical conduction within 33 μs. 0.45 mg of copper azide can generate a 3.27 GPa detonation wave within 5.9 μs at 0.3 mm in the air domain to realize the physical self-destruction of the ISC. This scheme can greatly improve the safety of the energetic materials and provides strong practical value for information self-destruction.

Novel Harmonic Current Controller for DC-Biased Vernier Reluctance Machines Based on Virtual Winding

Direct current-biased vernier reluctance machine (DC-biased VRM) adopts a doubly salient structure and sinusoidal phase currents. It has better performance than switched reluctance machines and variable flux reluctance machines. The back electromotive force (EMF) waveforms of DC-biased VRMs contain low-order harmonics. It leads to harmonic currents in phase windings. The current harmonics increase the losses and worsen controller performance. The suppression of current harmonics has become a hot research topic in literatures. However, the existing harmonic suppression methods have their inherent defects. In this paper, a novel harmonic current controller based on virtual winding is proposed. Harmonic currents are decoupled and transformed into different harmonic planes, and independent closed-loop control is realized. The characteristics of harmonic planes and the relationship between them are analyzed. According to the analysis, the method of choosing valid planes and harmonic distribution is introduced. The major advantage of the proposed method is that, harmonic current sampling and control can be realized without the use of filters, and it avoids complicated design of controller parameters. Experimental results based on a DC-biased VRM are presented. It verifies that the proposed current control strategy based on virtual winding shows excellent harmonic control performance.

Topology Optimization of Synchronous Reluctance Motors Considering the Optimal Current Reference in the Field-Weakening and Maximum-Torque-Per-Voltage Regions

The torque performance of the synchronous reluctance motors (SynRMs) is primarily determined by the geometric design and current control. The motor structure needs to be designed to yield the maximum output torque under the given current and voltage limitations. The current reference supplied to the stator coils also needs to be determined to maximize the output torque while suppressing the back electromotive force (EMF) to protect a power supply system. However, in the field of design optimization, it has been challenging to simultaneously consider the geometric design and current control due to their complicated relationships. To solve the aforementioned issue, this study proposes a new topology optimization that can cover the maximum-torque-per-ampere (MTPA), field weakening (FW), and maximum-torque-per-voltage (MTPV) controls under both the current and voltage limitations, thereby maximizing the output torque in an entire rotational speed range. To effectively investigate the coupling effects between the geometric design and current reference, this study proposes the design parameterization for the FW and MTPV operation by performing the electromagnetic finite element (FE) analysis and then expresses the optimal current reference in terms of design variables. At every iteration, the structural FE analysis is also performed under the design-dependent loads to obtain a structurally meaningful design. By doing so, both the optimal design and the corresponding optimal current reference can be simultaneously determined. The optimized SynRM is manufactured and experimentally validated to demonstrate the effectiveness of the proposed optimization framework.

Investigation of Permanent Magnet Vernier Machines with different PM Arrays

Two new five-phase out-rotor inner-stator permanent magnet (PM) vernier machines (PMVM) with different PM arrays are proposed to investigate the performance compared with an existing PMVM. The Halbach arrays and consequent arrays are adopted to enhance torque density. Also, the operation principle of PMVM is discussed by an analytical method. Moreover, some parameters are optimized to achieve better performance. Finally, performance such as back electromotive force, torque, loss, and efficiency are discussed by the finite element method.

Analysis and Calculation of Inductor Parameter for PWM rectifier

In the PWM rectifier, the rationality of the AC side filter inductance design directly affects the performance of the whole system. It not only limits the power output, but also affects the dynamic and static response of the current loop. It has an important influence on the four quadrant stable operation of the motor, the isolation of the grid electromotive force and the harmonic suppression of the current. According to the waveform characteristics of the sinusoidal current, the maximum change rate of the current occurs at the zero-crossing point. In this paper, the inductor is designed to meet the requirement of the change rate of the current near the zero-crossing point, so as to meet the tracking requirement of the current at any time in the whole cycle. In addition, for the design of the AC side inductance, this paper comprehensively designs from the perspective of meeting the requirements of power index and meeting the requirements of suppressing harmonic current.

Catalysis Under Alternating Magnetic Field: Rethinking the Origin of Enhanced Hydrogen Evolution Activities

AbstractMagnetic fields are proposed to be a clean and powerful tool to boost the heterogeneous reaction processes, from the simple two‐electron transfer hydrogen evolution to the complicated proton‐coupling of multi‐electron transfer reactions. Although many mechanisms are proposed to explain the field‐assistant enhancement of activities, it remains an open question of how to understand the contradictory experiment results. In this study, the interplay between the alternating magnetic field (AMF) and the working electrodes from the viewpoint of their relative geometric positions is investigated. It is found that the HER current is almost doubled at an AMF of 25 mT when Pt foil and AMF are parallelly arranged, which is more significant than the perpendicularly arranged configuration. A significant increase in solution resistance is observed, which is in contradiction to previous works. The changing of currents with the AMF strength is investigated for the diamagnetic Cu, ferromagnetic Ni, and paramagnetic Ti and Pt wire, all suggesting the vital role of the induced electromotive force, which is a result of the relative geometric positions between the electrode and AMF. The findings provide an alternative mechanism for the magnetic field‐assisted electrocatalytic processes, which is helpful for the rational design of high‐performance catalysts.

(Invited) Thermodynamic Properties of Rare-Earth Alloys Relevant for Efficient Rare-Earth Recovery in Molten Salts

Electrode materials of Fe, liquid Bi, and Sn were investigated to enhance the electrochemical recovery of rare-earth elements in molten salts (eutectic LiCl-KCl) at 500‒700 °C, leveraging their chemical interactions with rare-earth elements. Using Nd as a prototypical example, the degree of interactions was quantified based on electromotive force (emf) measurements of Nd alloys (Nd-Fe, Nd-Bi, and Nd-Sn). Temperature-dependent emf values of the Nd alloys were used to determine the thermodynamic properties such as the partial molar Gibbs energy (chemical potential), entropy, and enthalpy of Nd. In addition, the phase behavior of Nd alloys was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) to determine transition temperatures and microstructures of Nd alloy electrodes. Based on these fundamental properties of Nd alloys, the Nd-Sn alloy at mole fraction, x Nd = 0.10 was selected as the reference electrode and employed for electrochemical measurements in three-electrode cells in molten chloride salt (LiCl-KCl-NdCl3). The stability of Nd-Sn reference electrode was maintained less than 1 mV deviation between identical constructs during entire measurements, originating from the two phase (liquid + NdSn3) stability of the binary Nd-Sn alloy at 500‒700 °C. Finally, electrodeposition of Nd onto these interacting electrode materials was conducted to assess the recovery efficiency of Nd from molten chloride salt.

Flow Battery Driven by a Difference in Solvation Toward the Effective Use of Diverse Forms of Energy

Further utilization of renewable and waste energy is a crucial factor for the decarbonization of energy systems. We have recently proposed a concept of an electrochemical cell using a difference in solvation [1]. Figure 1 shows a flow battery derived from the concept, called solvation difference flow battery (SDFB). Although the anolyte and catholyte employ the same redox species, the ratio in the binary solvent is different. In this situation, the difference in the solvation states of the redox couple between the anolyte and catholyte generates the electromotive force. As shown in Fig.1, ferro-/ferricyanide ions (Fe(CN)6 4-/3-) are employed as the redox species in both anolyte and catholyte. The electrolyte solvent is composed of dimethyl sulfoxide (DMSO) and water. The anolyte is water-lean and the catholyte is water-rich, respectively. After discharging, the SDFB can be charged by transferring the water from the water-rich side (spent catholyte) to the water-lean side (spent anolyte), which means that the transfer of water regenerates the spent anolyte as the fresh catholyte, and vice versa. It is noteworthy that transferring the solvent can be performed by utilizing diverse forms of energy, such as thermal and mechanical energy as an energy input for the charge.We previously reported that the combination of DMSO and water allows a large cell voltage [1] owing to the significant difference in the electron acceptability between the solvents [2, 3]. However, the cell performance and its rate-determining processes have not been fully understood. In this work, we investigated the current-voltage (IV) characteristic of the DMSO/water-based SDFB using the prototype flow cell.For the electrolyte, tetraethyl ammonium salts of Fe(CN)6 4-/3- and tetraethyl ammonium bromide as redox species and a supporting electrolyte, respectively, were dissolved in DMSO and pure water was added to the solution to adjust the molar ratio of DMSO and water. The molar ratios of water in the anolyte and catholyte were kept at 0.1 and 0.8, respectively. The carbon paper electrodes were employed for both anode and cathode of the flow cell. The anion exchange membrane (AEM) was used as a separator. Therefore, bromide ion works as a carrier ion in this flow cell. As a result, the maximum power density of 4.5 W m-2 was observed for the prototype SDFB.We also conducted Electrochemical impedance spectroscopy (EIS) for the flow cell applying a symmetric electrolyte system to investigate the crucial factor that limits the power density. Both water-lean and water-rich electrolytes were prepared for the EIS to investigate the effect of the solvent composition. Moreover, in addition to the AEM used in the investigation of IV characteristics, porous filter was also used as the flow cell's separator to clarify the total cell resistance factor. The Nyquist plots represented the large cell resistance when the AEM and water-lean electrolyte was applied. On the other hand, the cell resistance was small when the porous filter was utilized as the separator, regardless of the molar ratio of water in the electrolyte. The Nyquist plots also indicated that the reaction resistance was relatively small.Therefore, these results indicate that the large AEM resistance influences the total cell resistance in the water-lean electrolyte (anolyte). These results imply that it should be a practical approach to develop an alternative SDFB electrolyte that can avoid the significant AEM resistance for increasing the power density. From the viewpoint of the cell assembly, the exploration of alternative separators that exhibits both high ion conductivity in the water-lean electrolyte and low permeability of solvent molecules should drastically improve the power density of the DMSO/water-based SDFB.