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Hierarchical porous carbon materials have received significant attention for application in catalytic water splitting because of their high efficiency, cost-effectiveness, and biocompatibility. In this study, laser-induced graphene (LIG) was fabricated on a carbon film- (CF-) type substrate for an efficient hydrogen evolution reaction (HER). The LIG-CF electrode was fabricated via laser-induced graphitization on a commercial polyimide (PI) film, followed by the pyrolysis of the LIG on the PI film (LIG-PI). During pyrolysis, the microscopic and material properties of the LIG remained intact, as verified through various characterizations. The as-prepared all-carbon electrode was then utilized as an electrode for the HER study in a 1.0 M KOH electrolyte and compared with LIG-PI and Pt electrodes. In the HER experiments, the optimized LIG-CF electrode exhibited excellent catalytic performance with zero-onset potential, and the potentials required to achieve high current densities of 10 and 20 mA/cm2 were 134 and 139 mV (vs. reversible hydrogen electrode (RHE)), respectively. The excellent performance of the LIG-CF electrode originates from the hierarchical porous structure of the LIG material, which serves as an electrochemically active site, and carbon substrate that facilitates the fast transport of ions at the electrode/electrolyte interface. Additionally, the carbon substrate shortens the transportation length of electrons which played a significant role for the enhanced performance of the LIG-CF electrode. [ABSTRACT FROM AUTHOR]

Electrode materials for large-scale applications from the earth-abundant material need to be developed in the energy storage system. Based on earth-abundant material, sodium-based batteries with Fe system-based positive electrodes seem attractive for a cost-effective system for large-scale storage applications. Instead of partial substitution of transition metals with Fe, in the present work, we choose surface coating to analyze the electrochemical performance of NaFeO2. SnO was coated on the NaFeO2 surface, and the electrochemical characteristic property is studied in detail. Spongy nanoball coating is confirmed on the surface of NaFeO2. The reversible capacity of SnO-coated NaFeO2 is about 158 mAh·g-1 at 0.25 C. The SnO coating greatly enhances electron transport during cycling, and 80% of capacity is retained after 1000 cycles. The enhanced electrode can be used as a cost-effective, eco-friendly natured electrode with high performance for large-scale energy storage applications. [ABSTRACT FROM AUTHOR]

Summary: In this article, the electrode performance of the misfit‐layered calcium cobaltite (C349), as cathode for solid oxide fuel and anode for solid oxide electrolysis cell (SOEC), is analysed by electrochemical impedance spectroscopy using a 3‐probe cell configuration. The addition of Ce0.8Gd0.2O2−δ (CGO20) as a composite electrode phase significantly boosts the electrochemical processes, decreasing the polarisation resistance (Rp) by approximately half an order of magnitude over the studied temperature range (550°C‐700°C). Electrical measurements under cathodic and anodic polarisation indicate that the C349/CGO20 composite is a promising oxygen electrode for reversible solid oxide cells with enhanced performance when operated as a SOEC anode. Short‐term stability testing of 50 h, under anodic polarisation at 700°C, demonstrates a stable current density with no observable microstructure delamination after measurements, being promising to avoid common degradation issues during SOEC operation. [ABSTRACT FROM AUTHOR]

Summary: Construction of a high‐sulphur‐loading electrode is an effective approach for achieving a high‐specific energy density in lithium‐sulphur batteries. The polymer binder has an important influence on the microstructural and electrochemical behaviours of high‐sulphur‐loading electrodes. In the study, three commonly used binders, namely polyvinylidene fluoride (PVDF), polyacrylonitrile (LA133), and polyacrylic acid (PAA), were used with high‐sulphur‐loading electrodes, and their electrochemical performance characteristics were investigated. The water‐soluble binders LA133 and PAA showed significantly better performance than PVDF. The PAA binder effectively decreased the overpotential polarisation and resistance, increasing the lithium‐ion diffusion coefficient and accelerating the redox reaction of polysulphides. The CNTs@S electrode with PAA as the binder showed the first discharge specific capacity of 703 mAh g−1 at a sulphur loading of 5.1 mg cm−2 at 0.3 C, with a decay rate of 0.1% over 150 cycles. Even with a higher sulphur loading of 7.1 mg cm−2, the electrode exhibited an initial capacity of 6.3 mAh cm−2 at a current density of 1.19 mA cm−2 and capacity retention of 98.4% over 50 cycles. In addition, the electrode with the PAA binder showed significantly increased volume energy density. The aqueous PAA binder is more suitable for the fabrication of high‐sulphur‐loading electrodes for lithium‐sulphur batteries. [ABSTRACT FROM AUTHOR]

Summary: One of the challenging problems to solve in the design of high‐performance supercapacitors (SCs) is converting the surface of the electrodes to porous nature. Therefore, this study is aimed to increase the surface area of the NiZn electrodes by using a fast and low‐cost technique which is based on alloying/dealloying the metals. Nickel/Zinc (NiZn) alloy was obtained by depositing Zn electrochemically on porous Ni foam. Later, by using the galvanostatic scanning technique, Zn was dealloyed and the surface area was further enlarged. Electrochemical properties of alloyed and dealloyed NiZn electrodes were first evaluated as half‐cell configuration in 6 M potassium hydroxide (KOH) solution with respect to Pt electrode. Then, two different asymmetric SCs, Cu‐NiZn(alloyed) and Cu‐NiZn (dealloyed) were constructed and characterized as the two‐electrode configurations in the same electrolyte. Cyclic voltammetry at different scan rates from 5 to 200 mV/s and galvanostatic charge‐discharge techniques at different current densities varying from 2 to 50 A/g were used to carry out the capacitive properties of the SCs. It was clearly observed that dealloying the electrode results in increasing electrochemical performance as expected where the maximum energy and power densities increased to 12.2 Wh/kg and 30.4 kW/kg, respectively. [ABSTRACT FROM AUTHOR]

Summary: Nitrogen and sulfur heteroatom‐doped graphene oxide (GO) electrodes were produced with a fast, eco‐friendly, and, more significantly, functional group‐controlled technique, chronoamperometry. N‐doped GOs (N‐GOs) and S‐doped GOs (S‐GOs) as binder‐free positive electrodes were designed to boost the performance of vanadium redox flow battery as the positive electrodes. The prepared as positive electrode materials for vanadium redox battery were characterized with cyclic voltammetry, Raman spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy. The electrochemical performance of the prepared GO electrodes was investigated through cyclic voltammetry and electrochemical impedance spectroscopy. While S‐GOs containing S, and O‐containing functional groups were shown high electrical conductivity and stability, N‐GOs, containing N and O‐containing functional groups were slightly lower electrochemical performance. Among the high‐performance electrodes, the S‐GO21 synthesized by applying +2.1 V constant potential via the chronoamperometry method exhibited the best performance as the positive electrode for vanadium redox battery. This electrochemical activity result can be correlated to the more S‐ and O‐containing functional groups on the surface of GO. [ABSTRACT FROM AUTHOR]

Summary: Considering the limit of resources and the frequent use of energy, energy storage is nowadays the subject that everyone cares about. In the present work, we investigate trijunction metal oxides as supercapacitor electrode for energy storage application. A MnO2/NiO/ZnO trijunction electrode is synthesized for the first time using a successive three electrochemical deposition steps onto stainless steel (SS) substrate. This approach can effectively yield a good distribution and adhesion of all metal oxides onto the substrate with enhanced hydrophilicity and wettability. The specific capacitance of this trijunction electrode, as studied by cyclic voltammetry was higher than that of individual metal oxide electrodes. The maximum specific capacitance was estimated to be 1569.75 g−1 at a scan rate of 5 mV s−1. The enhanced electrochemical performance of this trijunction electrode compared to single metal oxide electrodes (MnO2, NiO, or ZnO) is mainly due to the improvement of ion and electron transportation pathways in the combination of three metal oxides electrode. In addition, this study presents an Artificial Neural Network (ANN) model to predict cyclic voltammetry behavior of the prepared trijunction supercapacitor electrode, with a high satisfactory performance for the predicted performance with <0.05% error. The low and simply synthesized hierarchical trijunction electrode with superior electrochemical performance and the good correlation between experimental and theoretical results prove huge potential for its practical application in supercapacitors (SCs). [ABSTRACT FROM AUTHOR]

Summary: In this study, stimulating approach electrodeposition has been espoused to fabricate binder‐free electrodes of transition metal sulfides to achieve high electrochemical performance for energy storage devices. Here, the effect of Co and Cu with MnS has been scrutinized by gradually replacing Co with Cu concentration. The fabricated electrodes have been examined by FESEM to analyze the structural morphology of the material. Furthermore, electrochemical characterizations have been carried out for exploring the electrode performance which reveals that the S4 electrode (Cu0.75Co0.25MnS) exhibits the best performance as compared to contender electrodes. This electrode exhibits a high specific capacitance of 4800 F/g at 10 A/g current density with a smaller ESR value of 0.48 Ω. Additionally, the S4 electrode has been used as a cathode and activated carbon (AC) as an anode in assembling of supercapacitor device. Device S4//AC portrayed a maximum energy density of 118 Wh/kg with a power density of 960 W/kg at 1.2 A/g. The obtained results prophesied that the electrochemical performance of metal sulfides has been intensified by varying the concentration of material for superior electrochemical applications. [ABSTRACT FROM AUTHOR]

Summary: In this work, SnS/SnS2 heterostructured film on a nickel foam (NF) through solution process was grown and employed directly as cathode and anode to the urea oxidation reaction (UOR). The as‐fabricated SnS/SnS2 film achieves high efficiency toward UOR with a lower potential of 1.38 V vs RHE to deliver 50 mA cm−2, which is approximately 200 mV less than the potential demanded for the oxygen evolution reaction (OER). More importantly, the electrolyzer consisting of two identical electrodes with the SnS/SnS2/NF ǁ SnS/SnS2/NF vs RHE assembly oxidizes urea at a lower potential of 1.36, 1.38, and 1.39 V vs RHE to deliver a current density of 10, 50, and 100 mAcm−2, respectively. The superior UOR performance of the SnS/SnS2‐based electrode is attributed to the combined merits of the SnS and SnS2 phases in the heterostructure, enhancing the catalytic active sites and providing the easy charge transport between the electrode and electrolyte. [ABSTRACT FROM AUTHOR]

Summary: This work is aimed to synthesize hybrid nanocomposite electrode materials for supercapacitor applications. The carbon nanotubes (CNTs) are incorporated into MoS2 as well as TiO2 to form different hybrid electrode materials such as MoS2/CNTs, TiO2/CNTs, and MoS2/TiO2/CNTs in an effort to improve the electrochemical performance. The resulting hybrid electrode materials are examined by SEM, TEM, XRD, XPS, and Raman studies. Cyclic voltammetry and galvanostatic charge‐discharge tests are used to evaluate the specific capacitance and charge‐discharge stability of the synthesized MoS2/TiO2/CNTs. Among the hybrid electrode materials investigated, the MoS2/TiO2/CNTs exhibits superior electrochemical performance with specific capacitance of 1252.57 mA h/g at a scan rate 20 mV/s as compared with MoS2/CNTs (810.53 mA h/g), TiO2/CNTs (607.10 mA h/g), and CNTs (204.35 mA h/g). All electrochemical tests were carried out in a solution of 1 M KOH. The Rct and Rf for the MoS2/TiO2/CNTs electrode were found to be 1.7 Ω.cm2 and 2.1 Ω.cm2, respectively, which were significantly lower than the corresponding Rct (40.2 Ω.cm2) and Rf (51.1 Ω.cm2) for the CNTs electrode, indicating that the MoS2/TiO2/CNTs has a significantly lower overall impedance, which could be one of the key factors responsible for the improved electrochemical performance of the MoS2/TiO2/CNTs. Moreover, this MoS2/TiO2/CNTs hybrid electrode displays good cycling stability with the capacitance retention of 98.83% after 10 000 cycles of charge‐discharge at 1 A/g. The energy density and power density of MoS2/TiO2/CNTs composites are found to be 757.80 Wh/kg and 4546.80 W/kg respectively. [ABSTRACT FROM AUTHOR]

Summary: The applications of electrophoretic deposition (EPD) to the development of electrochemical energy storage (EES) devices such as batteries and supercapacitors are reviewed. A discussion on the selection of parameters for optimizing EPD electrode performance, such as light‐directed EPD, co‐deposition of active materials such as metal oxides and materials manufactured with high porosity and fibrous properties is highlighted. Additionally, means for overcoming obstacles in the improvement of the mechanical properties, conductivity and surface area of EES materials are discussed. The exceptional benefits of EPD such as low cost, small processing time, simple apparatus requirements, homogeneous coatings, binder‐free deposits and selective modification associated with thickness and mass loadings leading to effective EES electrode materials are highlighted. Finally, EPD processes have evolved as modern manufacturing tools to produce technologically improved solid electrolytes and separators for lithium‐ion and/or sodium‐ion batteries, and further research and development programmes are encouraged towards industrialisation. [ABSTRACT FROM AUTHOR]

Summary: Design of advanced highly porous heteroatom‐doped carbon is desirable for their wide presence in applications like electrochemical energy storage systems, gas adsorption, and separation processes. In this work, porous nitrogen‐doped carbon was developed from ethylenediamine via an in situ self‐doping solvothermal process followed by pyrolysis and KOH activation under high temperature. Micropore‐rich nitrogen‐containing carbon materials were prepared through variation of the KOH/C ratio during activation and their electrochemical performance in alkaline electrolyte as well as CO2 sorption behaviour was evaluated. The porous carbon developed using KOH/C ratio of 2 delivered highest supercapacitor performance in 6 M KOH achieving high specific capacitance of 353 F g−1 with 1 A g−1 of current due to its high pore volume and micropore rich surface. The functionalized carbon delivered CO2 uptake capacities of 4.48 and 3.0 mmol g−1 under temperatures of 273 and 298 K, respectively, at 1 bar pressure with a good CO2/N2 selectivity of 20.58 and CO2/CH4 selectivity of 3.83. The existence of nitrogen functional groups, high surface area, and micropore‐rich porous structures may be the essential reasons behind superior electrode performance and CO2 capture capacity of the material. This work hopefully offers a simple development of N‐doped carbon for effective energy storage and CO2 adsorption systems. [ABSTRACT FROM AUTHOR]

Summary: Nanostructured Ag‐decorated Co‐Co3O4 composite thin film (Ag/Co‐Co3O4) synthesized on nickel foam (NF) by a combination of cyclic voltammetry and pulse reverse potential electrodeposition modes presents higher specific capacitance and its retention. The higher specific capacitance of 2800 F/g on Ag/Co‐Co3O4/NF composite thin film in comparison with 2580 F/g on Co‐Co3O4/NF at 1 A/g is attributable to the presence of nanostructured Ag in the composite film enhancing the ionic and electronic conductivity of the material. The morphology revealed by the scanning electron microscope correlates the electrochemical and capacitance behavior while the energy‐dispersive X‐ray spectroscopy spectra confirmed the presence of Co, Ag, and O in the Ag/Co‐Co3O4/NF composite thin film. The attenuated total reflection‐Fourier transform infrared spectra obtained further confirmed the presence of Co–O bonds. The Ag/Co‐Co3O4/NF composite thin film presented an amorphous nature as revealed by the X‐ray diffraction spectra. In addition, the Ag/Co‐Co3O4/NF electrode exhibited a maximum specific energy of 69.5 Wh/kg, specific power of 6.6 kW/kg and capacitance retention of 82.6% after 1000 cycles, while the Co‐Co3O4 electrode (with no Ag) showed lower specific energy of 60.8 Wh/kg, specific power of 5.8 kW/kg, and a capacitance retention of 78.2% after 1000 cycles. Furthermore, by the incorporation of Ag, the composite electrode showed a reduction in the equivalence series resistance value from 1.5 Ω cm2 (Co‐Co3O4/NF) to 1.0 Ω cm2 (Ag/Co‐Co3O4/NF) as well as in the charge transfer resistance (Rct) from 2.86 Ω cm2 (Co‐Co3O4/NF) to 0.96 Ω cm2 (Ag/Co‐Co3O4/NF) indicating the positive influence of the presence of Ag in the film. The electrochemical evaluation indicates that a synergistic effect between Ag and Co‐Co3O4 enhances supercapacitor electrode performance. [ABSTRACT FROM AUTHOR]

Summary: This paper focuses on the long‐term tests for 1000 hours of different Membrane‐Electrode‐Interconnect Assemblies (MEIAs), consisting of a steel interconnect and an asymmetrical solid electrochemical cell based on the Ce0.8Sm0.2O2−δ electrolyte, the double‐layer working electrode with the La2NiO4+δ – Ce0.8Sm0.2O2−δ composite functional layer and the LaNi0.6Fe0.4O3−δ current collector layer, and the platinum reference electrode (O2, LaNi0.6Fe0.4O3−δ|La2NiO4+δ – Ce0.8Sm0.2O2−δ|Ce0.8Sm0.2O2−δ|Pt, O2). These tests were carried out on MEIAs with two types of Cr‐based stainless steels, Crofer 22 APU and 08X17T, with and without protective coatings at 850°C in air. The electrochemical performance of MEIAs was studied without polarization as well as under cathodic and anodic polarization (current density was 0.5 A cm−2) by means of electrochemical impedance spectroscopy (EIS) and the distribution of relaxation times method (DRT). It was found that the proposed protective coatings for the stainless steels inhibit chromium poisoning without polarization and under anodic polarization: for Crofer 22 APU the degradation of the polarization resistance after ~1100 hours of exposure was 0.35 ± 0.05 Ω cm2, and for 08X17T it was from 0.40 ± 0.05 Ω cm2. In the case of cathodic polarization, the degradation of the polarization resistance remained at a very high level, comparable to uncoated samples: for Crofer 22 APU and 08X17T with coatings, it was about 0.6 to 0.8 Ω cm2 after ~1100 hours. Post‐test analysis of the microstructure and chemical composition of the interconnect ‐ double‐layer electrode interface was carried out using scanning electron microscopy (SEM), wavelength dispersive X‐ray spectrometry (WDS), and respective image analysis of the obtained data. The influence of chromium poisoning on the degradation was considered for different stages of the electrode performance. It was demonstrated that chromium predominantly accumulates in the current collector layer in the case of anodic polarization and in the functional layer in the cases of open circuit and cathodic polarization. For the first time, a combined electrochemical‐chemical degradation mechanism of the La2NiO4+δ – Ce0.8Sm0.2O2−δ functional layer was discussed. Highlights: Long‐term tests of Membrane‐Electrode‐Inteconnect Assembles (MEIAs) were done.Chromium poisoning was detected on MEIAs with the interconnects without coating.Cathodic polarization terminates the protective properties of the coatings.Chromium poisoning decreases electrode activity to oxygen exchange and diffusivity.A combined electrochemical‐chemical degradation mechanism of the functional layer was revealed. [ABSTRACT FROM AUTHOR]

Summary: Modified (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO)‐mediated oxidation (MTMO) is introduced to fabricate low‐defected carboxylic acid functional group–rich carbon nanotube (TEMPO‐CNT) through facile and eco‐friendly chemical preparation. Due to the MTMO, the O=C‐O portion (18.2%), representing the amount of active site to vanadium ion redox reaction (VIRR), reaches the nearly same with conventionally acid‐treated CNT (AT‐CNT, 18.9%). However, the intensity ratio of D to G band of TEMPO‐CNT is measured lower value (1.14) than that of AT‐CNT (1.29) in Raman spectra, showing the MTMO is the better strategy to functionalize carboxylic groups on CNT with the uniform structure and low‐defected feature. Furthermore, when the TEMPO‐CNT is utilized for the catalyst for VIRR, the catalytic activity increases to 2.11 (negolyte) and 2.03 (posolyte) times compared to AT‐CNT, and the reversibility of VIRR is also improved. These results attribute to the 41.6% lower charge transfer resistance than AT‐CNT, demonstrating that the low‐defected CNT structure of TEMPO‐CNT induced a facile electron transfer, resulting in the high catalytic performance. With that, the energy efficiency (EE) and discharge capacity of vanadium redox flow battery (VRFB) adopting TEMPO‐CNT display 58.8% and 16.8 Ah L−1 even at high current density (250 mA cm−2), whereas those of AT‐CNT are only 52.3% and 6.8 Ah L−1. Regarding long‐term stability, the TEMPO‐CNT and AT‐CNT preserved 98.8% and 91.4% of retention rate in EE at 200 mA cm−2 for 200 cycles, respectively, indicating that the MTMO is the promising option to fabricate the catalyst to use in the practical VRFB. [ABSTRACT FROM AUTHOR]

Summary: Lithium‐ion battery (LIB) systems provide a very promising range of power supply systems for diverse applications like electric vehicles, hybrid plug‐in electric vehicles, grid storage systems, and microelectronics. Nevertheless, the features of lithium‐ion batteries (LIBs), which include energy density and power, cycle lifetime, safety, as well as cost, must be enhanced in order to achieve all these feasible applications. Atomic layer deposition (ALD), as a result of its unique benefits above other thin‐film methods of deposition, emerges as a very useful approach for use in improving the efficiency of LIBs. This review summarizes ALD's advanced successes in designing new nanostructured solid‐state electrolytes and electrode materials, as well as the adjustment of the interfaces of electrodes and electrolytes through the application of surface coatings for the avoidance of undesirable side reactions to attain maximum adequate performance of the electrode. Also covered are ideas for the potential advancement of ALD studies and technology for the applications of LIBs. This review paper is anticipated to furnish researchers within the LIB and ALD fields with valuable information that would encourage much more extensive research on the use of ALD to produce new generation LIBs. Novelty Statement: This review presents the recent advancements in electrode materials as well as some new electrode fabrication processes for Li‐ion batteries. Certain prospective materials with improved electrochemical performance have also been reported, along with a review of the recent precursors utilized for the ALD of battery materials. The efficiency of the ALD process in providing sufficient solutions to the problems associated with the utilization of Lithium‐ion batteries is also discussed. [ABSTRACT FROM AUTHOR]

Summary: The electrode materials with high rate capability are required to meet the ever‐demanding performance of rechargeable batteries. Herein, sulfur‐doped molybdenum phosphide (S:MoP) is prepared using (thio)urea‐phosphate‐assisted strategy and investigated as anode material for Li‐ and Na‐ion batteries. This approach provides the self‐doping of sulfur in MoP lattice that stabilizes the least stable oxidation state of phosphorus (P−3) of MoP through Mo/P–S bonds, enhances the electronic conductivity, and maximizes the Li‐/Na ions adsorption sites. The phase pure hexagonal S:MoP is obtained at 700°C (S:MoP‐7) and the complete reduction of phosphate is confirmed through X‐ray diffraction as well as X‐ray absorption spectroscopy. The presence of chemical bonding of Mo‐P/S and P‐S is detected by X‐ray photoelectron spectroscopy. S:MoP‐7 anode shows excellent rate capability where it delivers 112 mAh g−1 capacity at 12.8 C rate and high stability with 436 mAh g−1 capacity at 100th cycle at 0.1 C rate when tested in lithium‐ion batteries. The S:MoP‐7 as an anode exhibits high rate capability in sodium‐ion batteries and delivers 133 mAh g−1 capacity at 6.4 C rate and 307 mAh g−1 at 0.1 C rate at the 100th cycle. The high performance of the S:MoP‐7 electrode is attributed to the interconnected porous network, increased active sites for Li‐ and Na‐ions via S‐doping, and reduced charge transfer resistance as observed using electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]

Summary: This study reports the enhanced performance of protonic ceramic fuel cells by adopting electrode‐electrolyte cathode functional layers (CFLs). PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) and BaZrxCe0.8−xY0.1Yb0.1O3−δ (BZCYYb) were used as cathode and electrolyte materials, respectively. Thin‐film CFLs comprising PBSCF and BZCYYb composites were inserted between the electrode and the electrolyte. Power output in the cells with CFLs was enhanced by approximately 4% to 20% at a temperature range of 450°C to 550°C, compared to those without CFLs. Impedance analysis confirmed that the polarization electrode resistance significantly reduced with the adoption of CFLs. The extended interface between the cathode and electrolyte in the CFLs was considered to have contributed to the reduced electrode impedance. The distribution of relaxation times analyzed by fitting the impedance data revealed the charge transfer and proton incorporation steps along with the PBSCF/BZCYYb interface in CFLs as the main contribution to the electrode performance enhancement in cathodic polarization reactions. [ABSTRACT FROM AUTHOR]

Summary: An appropriate electrode microstructure design should be necessary to achieve high‐performance anion exchange membrane fuel cells (AEMFCs). In general, the electrodes are fabricated from catalyst slurries which contain self‐assembled agglomerates of catalyst particles with ionomer dispersed in a solvent. Therefore, solvent nature greatly affects the microstructure of the electrode, such as the pore structure and the formation of triple‐phase boundaries for electrochemical reactions. Here, we investigate the influence of solvent on the microstructure of I2 ionomer‐based electrode and its performance using three alcohol‐based solvents (ethanol, 2‐propanol, and 2‐methyl‐2‐propanol [tBuOH)) with different dielectric constants and similar boiling points. Various physical and electrochemical characterization confirmed that the electrode pore structure changes significantly depending on the type of solvent while the electrochemically active surface area hardly changes. Furthermore, the efect of the three electrodes with different pore structures on AEMFC performance is observed for anode and cathode, respectively. It is demonstrated that the porous electrode with large pores is more advantageous in performance than a dense electrode at both the anode and the cathode for AEMFC. Consequently, the membrane electrode assembly with porous tBuOH‐based electrodes exhibits more than 40% higher performance (1.32 W cm−2) than dense ethanol‐based electrodes (0.94 W cm−2). [ABSTRACT FROM AUTHOR]

Summary: Extensive attention has been given for the fabrication of stable and cost‐effective electrolytes materials for wearable energy storage systems. Herein, glycerol (Gly) and H3PO4 (P) based bio‐electrolyte for electrical double layer capacitance (EDLC) was produced and then converted to redox‐mediated gel bio‐electrolytes via doping with cobalt ions (Co) at various compositions to form glycerol‐H3PO4‐Co (GlyPCoX; X: 1%, 3%, 5%, 10% w/w). The gel electrolyte forms a hierarchical framework for effective ion conduction between the pores of the carbon composite electrodes that is triggered by bias during charging and discharging processes. The supercapacitors (SCs) were assembled with activated carbon‐based composite electrodes and device performances were tested according to redox‐mediated electrolyte compositions. Remarkable device performance was obtained from the Gly, which contained 5 M H3PO4 (P5) and 5% Co (Co5), (GlyP5Co5) and showed a specific capacitance of 349 F g−1. The corresponding specific energy and specific power were calculated as 47 and 420 W kg−1. Excellent operational stability (91%) was obtained after 15 000 charge/discharge cycles. In addition, the electrolyte is cost effective, retained extraordinary performance during galvanostatic charge‐discharge (GCD), and successfully powered light‐emitting diode (LED) device (1‐4 cm) at various bending angles. Thus, the gel electrolyte has excellent stability and flexibility for use in wearable energy storage systems. [ABSTRACT FROM AUTHOR]

Summary: The development of high‐performance porous electrode is highly desired in microfluidic fuel cells (MFCs) to improve their output for real‐world applications. Previous studies have mainly focused on the electrochemical modification of the porous electrodes to enhance their reaction kinetics. Yet, less attention was paid on the optimization of the electrode porous structure for improved mass transport. To identify proper optimization strategies, a computational model of flow‐through type MFC with porous electrodes is established in this work and systematic numerical analyses are conducted to compare the effects of the kinetic and structural parameters of the anode and cathode on the cell performance. Simulation results show that the constraint from the anode is more severe and concentration polarization brought by the insufficient mass transfer in the porous electrodes dominates the cell performance. Thus, structure optimization of the porous electrode for enhanced mass transfer is more promising in the performance enhancement of MFCs in comparison with the electrochemical modification. The specific surface area of the anode is identified as the most influencing factor. After proper structure optimization, an increase of 62.2% can be obtained in the current density at 0.8 V, which is three times of that in the electrochemical modification case. Based on the results, useful guidance is provided for the future development of MFCs. Novelty Statement: A computational model of MFC with flow‐through porous electrodes is established. Simulation results show that structure optimization of the porous electrode for enhanced mass transfer is more promising in the performance enhancement of MFCs in comparison with the electrochemical modification. After proper structure optimization, an increase of 62.2% can be obtained in the current density at 0.8 V. [ABSTRACT FROM AUTHOR]

Summary: A conductive agent, which is typically added to overcome the low electronic conductivity of Ni‐rich‐layered oxides, plays a significant role toward performance improvement of layered‐oxide‐based cathodes. Herein, the effects of the specific surface area, powder density, and aggregation characteristics of a conductive agent on Li1.03Ni0.88Co0.08Mn0.04O2 (Ni‐rich NCM) cathode performance are studied. The aggregation of conductive agents is disadvantageous for the distribution/arrangement of active materials and leads to polarization on the electrode surface. The specific surface area, which is proportional to porosity, contributes to the acceleration of electrode kinetics. However, the application of high pressure that makes a conductive agent excessively dense can degrade kinetic performance in the electrode. The low powder density of a conductive agent results in a nonhomogeneous electrode morphology and inhibits the mobility of Li ions in the electrolyte because of the segregation of the active materials from conductive agents. Powder density has a dominant effect on electrochemical performance. Even if the same active material is used, cycle retention is improved by 15%. In conclusion, the larger the specific surface area, the lower the powder density. Moreover, the less well‐aggregated the conductive agent, the higher the performance of the Ni‐rich NCM cathodes. [ABSTRACT FROM AUTHOR]

Summary: In this work, as an alternative to the silicon‐based anodes, Li22Si5/rGO composite electrodes were synthesized and their electrochemical performances were investigated by the electrochemical impedance spectroscopy, cyclic voltammetry, and charge/discharge tests. The effects of rGO and PVDF contents on the performance of the composite electrodes were also observed. Although the composite electrodes with the low PVDF content exhibited a high discharge capacity, their cyclic performances were very poor. The excess amount of PVDF content, however, even in the presence of high rGO content, caused the charge transfer resistance and the discharge capacity irreversibility to increase in the composite electrodes. The composite electrode with 70% Li22Si5 alloy, 15% rGO, and 15% PVDF (LSRGO15) contents exhibited the best electrode performance in this work. The LSRGO15 electrode had 822 mA h g−1 discharge capacity at the 100th cycle. These performance values demonstrated that Li22Si5/rGO composite electrodes were highly promising as the alternative anode materials for the LIBs. [ABSTRACT FROM AUTHOR]

As a promising technology to address the energy storage challenge, reversible solid oxide cell (RSOC) plays a vital role in conversion between chemical energy and electrical power. Over the last several decades, developing high performance fuel electrodes suitable for reversible operation have attracted extensive attentions. This work develops La0.1Sr0.85Ti0.35Fe0.6Ni0.05O3-δ which is an A-site deficient design with B-site having additional 5% nickel as the fuel electrode through in-situ metal exsolution. The in-situ exsolution process results in FeNi3 alloy particles, about 40 nm in size, while maintaining the perovskite structure of the parent oxide. The FeNi3 nanoparticles greatly improve the electrochemical performance as RSOC fuel electrode such as reducing the interfacial polarization resistance at 800°C by 13.6%, increasing the peak power density by 19% in the fuel cell mode and increasing the current density by 30% in the electrolysis mode. Furthermore, RSOC operation is demonstrated by 20-cycle reverse tests that are conducted by switching between the fuel cell and electrolysis modes. The stable RSOC performance indicates that La0.1Sr0.85Ti0.35Fe0.6Ni0.05O3-δ with in-situ constructed FeNi3 nanoparticles is a potential fuel electrode material for RSOC. [ABSTRACT FROM AUTHOR]

Summary: Transition metal oxides have attracted a special interest in the applications of energy storage and conversion devices because of their distinctive structural, electronic, and catalytic properties. In the current study, the effect of substrate temperature on binder‐free undoped CuO and Cr‐doped CuO (~4.5 at. %) thin‐film electrodes prepared by radio frequency sputtering technique is reported for supercapacitor applications. X‐ray diffraction studies revealed the formation of undoped CuO and Cr‐doped CuO films with monoclinic structure, while field emission scanning electron microscopy showed a significant change in the shape and size of the grains as a function of the substrate temperature. X‐ray mapping indicated a uniform distribution of the elements present in these films. Substitution of Cr of ~4.5 at. % has not altered the primary monoclinic structure of CuO, but the doped CuO thin‐film electrodes showed an improved conductivity. The electrochemical supercapacitive performance of the thin‐film electrodes was studied using cyclic voltammetry, galvanostatic cycling with potential limitation, and electrochemical impedance spectroscopy techniques in 1 M KOH. The electrochemical measurements revealed that the thin‐film electrode of Cr‐doped CuO electrode developed at the substrate temperature of 573 K exhibited the highest areal capacitance of 209 mF cm−2 at a scan speed of 10 mV s−1, which is five times higher than that of the pure CuO (38 mF cm−2) thin‐film. Furthermore, the Cr‐doped CuO thin‐film electrode exhibited excellent cycling stability with the capacity retention of 88% for 3000 continuous CV cycles in 1 M KOH. These results suggested that the binder‐free Cr‐doped CuO film electrodes prepared at the substrate temperature of 573 K is an excellent candidate material for the supercapacitor applications. [ABSTRACT FROM AUTHOR]

Summary: Modification of volume expansion and poor conductivity of ternary metal molybdates as an anode for lithium‐ion batteries (LIBs) results in the improvement of their reversibility and rate capability. Herein, porous rod‐like cobalt molybdate incorporated with nitrogen (N) doped reduced graphene oxide (rGO) was fabricated using a silicone oil‐bath method and further heated at 500°C (designated as CMO500@N‐G) and 600°C (CMO600@N‐G). The well‐designed CMO500@N‐G and CMO600@N‐G electrodes were explored as an anode for LIBs. Notably, the CMO500@N‐G electrode exhibited a discharge capacity of 612 mA h g−1 over 250 cycles at 100 mA g−1, while the CMO600@N‐G was restricted to 199.5 mA h g−1. Besides, the CMO500@N‐G electrode was sustained for 2000 cycles with a remarkable discharge capacity of 665 mA h g−1 even at a high current density of 1000 mA g−1. Finally, using a newly developed CMO500@N‐G anode, a full cell LIB was also fabricated and showed good reversibility and excellent rate performance. This outstanding performance of the electrode can be ascribed to the unique rod‐like morphology of cobalt molybdate with a highly conductive N doped rGO, which suggests a new strategy to fabricate high‐capacity anode materials for LIBs. [ABSTRACT FROM AUTHOR]

Summary: The supercapattery has achieved significant prominence for its high specific energy and power: however, still craved for electrodes with high ionic conduction and superior electrochemical performance. The study demonstrates the tuned electrochemical performance of cobalt phosphate via introducing a magnetron sputtered copper interfacial layer. Cobalt phosphate nanomaterials synthesized via the sonochemical approach was utilized as active electrode material. The magnetron sputter technique was employed to deposit copper on current collector (nickel foam). The structural studies and morphological aspects and elemental analysis were analyzed via X‐ray diffraction, scanning electron microscopy (SEM), and energy‐dispersive X‐ray spectroscopy. Atomic force microscopy (AFM) was performed to scrutinize the surface morphology of magnetron sputtered copper. The cobalt phosphate deposited on copper sputtered nickel foam profits a specific capacity (Qs) of 403.1 C/g (120.9% as compared to bare nickel foam) at 3 mV/s and 348.4 C/g (135.7% as compared with bare nickel foam) at 0.6 A/g in three electrode assembly. This electrode was further utilized in an asymmetric architecture (supercapattery device) that delivers outstanding Qs of 265.2 C/g with excellent Es of 62.6 Wh/kg and Ps of 425 W/kh at 0.5 A/g. The device also delivers an excellent Ps of 7924 W/kg while retaining Es of 11.8 Wh/kg at 7 A/g. Moreover, outstanding capacitive retention of 92.9% was observed after 5000 consecutive charge discharge cycles. In addition, the hybrid performance of the designed supercapattery was also explored via a theoretical methodology. The maximum diffusive and capacitive contribution of 88.81% (at 3 mV/s) and 55.11% (at 100 mV/s) was grasped by the device. To the best of our knowledge, this is the first approach toward the utilization of magnetron sputtered interfacial nanograins layer to tune the electrochemical performance of electrode material for potential supercapattery devices. [ABSTRACT FROM AUTHOR]

Summary: Porous carbon nanofibers (PCNFs) were produced from polyacrylonitrile (PAN)/polyvinyl alcohol (PVA) hybrid nanofibers with different mixing ratios and used as the free‐standing, flexible, high performance electrodes for the supercapacitors. The effect of PAN/PVA ratio, PVA removing and stabilization/carbonization process on the chemical structure, and the morphology of PAN/PVA hybrid nanofibers and PCNF were investigated by Fourier transform infrared (FT‐IR), field emission scanning electron microscopy (FE‐SEM), and thermogravimetric analyzer (TGA). It was proved by FT‐IR and FE‐SEM analyses that PAN/PVA hybrid nanofibers are successfully produced and carbonized. In addition, the electrochemical performance of PCNF electrodes was analyzed by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) methods. Results showed that PCNFs exhibit higher specific capacitance and better electrochemical performance than neat carbon nanofibers (N‐CNF). The specific capacitance of the EK5 PCNF (67/33 PAN/PVA wt ratio) was 157 F/g at 5 mV/s scan rate in 1 M H2SO4, while the specific capacitance of N‐CNF was 96 F/g at the same conditions. Moreover, the PCNF showed excellent cyclic stability without losing performance through 2500 charge/discharge cycles at a current density of 2 A/g. As a result, free‐standing, flexible, and high‐performance PCNFs are excellent candidates as supercapacitor electrodes for flexible energy‐storage devices. [ABSTRACT FROM AUTHOR]

Summary: An ideal catalyst material in the air electrode can reduce the over‐potentials and obtain an excellent electrochemical performance for lithium‐oxygen batteries. In this paper, Ag modified NixAlyMnzO2 polynary metal oxides (Ag@NAM) is synthesized by a facile precipitation method and as a bifunctional catalyst for high performance air electrode of lithium‐oxygen batteries. X‐ray diffraction and Raman spectrum test results show that the Ag@NAM catalyst has high crystallinity, which can prevent the lattice distortion caused by manganese dissolution and Ag staying on the surface can change the bond energy in order to supply some special catalytic effects. Through scanning electron microscope observation, Ag@NAM with the proportion of Ag and NixAlyMnzO2 polynary metal oxides to 8.5:1.5 has regular block morphology and uniform grain size. When an air electrode catalyst for lithium‐oxygen batteries, Ag@NAM can provide a large electrochemical reaction space along with enough oxygen atoms and lithium ions for electrocatalytic and electrochemical reactions. Specific discharge capacities can achieve to 6834.83, 6477.07, and 4357.14 mAh g−1 at 0.1, 0.2, and 0.3 mA cm−2 current densities, respectively. In addition, this air electrode can carry out stable 28‐time charge and discharge cycles. Hence, we feel that Ag@NAM catalyst can play an ideal bifunctional catalytic role and effectively reduce the polarization resistance. [ABSTRACT FROM AUTHOR]

Summary: Strontium (Sr) incorporated LaMnO3 (La0.7Sr0.3MnO3) nanoparticles have been synthesized by ball‐milling‐assisted solid‐state reaction to study their performance as electrode material for energy storage applications. The La0.7Sr0.3MnO3 nanoparticles exhibit superior electrochemical performance in neutral aqueous electrolyte (1 M Na2SO4) in comparison to LaMnO3 and SrMnO3 nanoparticles. This neutral electrolyte provides relatively higher ionic conductivity and viscosity compared to the ionic liquids and a wider potential window compared to the alkaline electrolytes. Electrochemical study of the electrodes prepared using La0.7Sr0.3MnO3 nanoparticles reveals pseudocapacitive behaviors with fast reversible Faradaic charge storage, which plays a key role in charge storage. The composite materials exhibit highest specific capacitance of 393.5 F g−1 at a scan rate of 2 mV s−1. Asymmetric supercapacitors fabricated using La0.7Sr0.3MnO3 nanoparticle and activated carbon operates over a wide potential window of 1.8 V, and it reveals high specific capacitance (197 F g−1) as well as high capacitive retention (87%) even after 4000 charge–discharge cycles. [ABSTRACT FROM AUTHOR]

Summary: Nanorods‐like structured ternary metal sulfides of Ni1‐xCuxS with various compositions (x = 0.1, 0.2 and 0.3), and binary sulfides of NiS and Cu9S5 were synthesised via a single‐step hydrothermal process. The structural properties and the functional groups of the synthesized materials were characterized by X‐ray diffraction (XRD) and Fourier transform infrared (FTIR) studies. Surface structure and chemical composition of the samples were inspected using field emission scanning electron microscopy (FE‐SEM) and energy dispersive X‐ray spectroscopy (EDAX). The electrochemical properties of the as‐synthesised metal sulfide based electrodes were investigated by cyclic voltammetry (CV) and galvanostatic charge‐discharge (GCD) analyses and the maximum specific capacitance (SC) of ~1092 F/g was achieved for the Ni0.8Cu0.2S at a current density of 15 mA/g, while pure NiS and Cu9S5 electrodes showed the minimum SC of ~575 and ~70 F/g, respectively. Further, the electrochemical impedance studies (EIS) revealed low Rct value (3.4 Ω) for the Ni0.8Cu0.2S electrode and improved electrochemical supercapacitor properties of Ni0.8Cu0.2S electrode because of to the synergistic effect and its well crystalline nanorods structure which offers more electrochemical active sites for faradaic reactions and fast electrolyte ions diffusion in to electrode. Additionally, the stability performance of the Ni0.8Cu0.2S electrode was performed at a fixed current density of 20 mA/g, and the Ni0.8Cu0.2S sample possesses the good cycling stability with the retention of 80% capacitance after 3000 GCD cycles. These results demonstrate that the as‐synthesised binary and ternary metal sulfides are suitable cost effective and pollution free electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

Summary: A three‐dimensional model was developed for an air‐breathing micro direct methanol fuel cell (μDMFC) with an extended anode catalyst region on the cell channels. The model was evaluated against experimental studies for a μDMFC under several anode distribution conditions, and the results showed a close agreement. The model was employed to study if catalysts coated on the fluid‐flow channel walls could enhance the power generation performance. Further, the effects of the anode catalyst loading of channel walls on the overall cell and individual electrode performances were examined. The modeling results indicated that the fuel cell with anodes both on the proton‐exchange membrane and on channel walls did not show superior performance to the fuel cell with anode catalysts only on the membrane since the overall power generation was mainly limited by the kinetics of the methanol electrode reaction but not the methanol transfer. The modeling results also demonstrated that increasing the anode catalyst loading on channel walls decreased the cathode potential due to an increase in the ohmic loss for the fuel cell with anode catalysts both on the membrane and on channel walls. Reducing channel dimensions decreased the ionic resistance and increased the methanol concentration at the anode and the methanol crossover flux to the cathode. [ABSTRACT FROM AUTHOR]

Summary: In this study, we report a new phosphotungstic acid‐Titania embedded polyaniline (PANI/PTA/TiO2) nanocomposite modified hybrid electrode for efficient methanol electro‐oxidation reaction. The PANI/PTA/TiO2 nanocomposite was prepared via a simple in‐situ polymerization method. The fabricated modified electrode's surface morphology and elemental analysis were characterized using field‐emission scanning electron microscopy with energy‐dispersive X‐ray spectroscopy and mapping technique. The phase structure and molecular vibrational studies were identified using an X‐ray diffraction and Fourier‐transform infrared spectroscopic techniques. The electrochemical performance of the modified electrodes was studied using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopic techniques. The PANI/PTA/TiO2 nanohybrid modified electrode displayed the superior electro‐catalytic activity towards methanol oxidation reaction at 0.2 V potential with the charge transfer resistance of 218 Ω, and showed excellent stability up to 1200s in an alkaline medium. The developed nanocomposite material can be used as a potential nanohybrid anode catalyst for the application of direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

Summary: Considering the low temperature demand (~550°C maximum) and high efficiency (~43%), Cu–Cl thermochemical water splitting cycle has immense potential as a futuristic scalable hydrogen generation process. CuCl/HCl electrolysis is the crucial hydrogen generation step in the Cu–Cl thermochemical cycle. The efficiency of this electrolysis process is highly dependent on the performance of the membrane electrode assembly (MEA) employed. To explore the suitability of the platinized membrane for this step, in this study, we have investigated a Pt/Nafion‐117 MEA prepared by in‐situ impregnation‐reduction method for CuCl/HCl electrolysis. A single‐cell PEM‐type electrolyser (4 cm2 active area) consisting of serpentine channels (2 cm × 2 cm) grooved in graphite flow field plates was designed and fabricated to carry out the CuCl/HCl electrolysis. Platinum electrocatalyst was deposited on Nafion‐117 membrane on the cathodic side by reduction of hexachloroplatinic acid (H2PtCl6) with sodium borohydride (NaBH4) by the impregnation‐reduction method which served as the MEA. Monodispersed nanocrystalline Pt particles formed a ~30 μm thick electrocatalyst layer on the membrane. Pt/Nafion‐117 MEA was found to be effective for CuCl /HCl electrolysis. In a PEM‐type electrolyser with Ar‐purged 0.2 M CuCl in ~2 M HCl solution as anolyte flowing at ~ 8.8 mLmin−1, a current density of ~100 mA cm−2 was achieved at a cell voltage of 1 V. However, undesired Cu‐crossover could be noticed from anode to cathode side during operation. [ABSTRACT FROM AUTHOR]

Summary: In this study, graphite (G) electrode was coated with nickel and decorated with silver nanoparticles (G/Ni/Ag) with the help of galvanostatic method, and electrodes were used as a cathode in alkaline water electrolysis system. The characterization was achieved using X‐ray diffraction and field emission scanning electron microscopy. Hydrogen evolution performance of electrodes was investigated via cyclic voltammetry, chronoamperometry, cathodic polarization curves, and electrochemical impedance measurements. Electrochemical results showed that hydrogen production efficiency significantly increased and charge transfer resistance decreased via G/Ni/Ag. The electrochemical water splitting performance of G/Ni/Ag, was established in a joint experimental and computational effort. Water and proton adsorption on Ag‐decorated Ni surface were investigated using density functional theory. Electronic structure calculations identified the role of Ag adatom and Ni surface on water and proton adsorptions. From the computational studies, O in water was more reliable to adsorb at the bridge position of the Ag and Ni atoms, leading improved orbital overlap between H and Ni atoms and maximized chemical and physical interactions between the H2O molecules. Therefore, the Ag‐decorated Ni(111) surface provides preferable adsorption site for the O atom in water and direct interactions between water Hs and available surface Ni atoms promote water dissociation. [ABSTRACT FROM AUTHOR]

Summary: Pure NiO or lithiated NiO with distinct Li/Ni atomic proportions (50/50—LN55 and 30/70—LN37) were tested as protective barrier layers (PBLs) to enhance the stability of LaCoO3 (LC) electrodes in cells with composite electrolytes (CEs) consisting of Gd‐doped ceria (CGO) and a eutectic mixture of Na and Li carbonates (NLCs). PBLs and LC layers were sequentially deposited by screen printing before firing at 700°C and 550°C, respectively, to yield symmetrical cells (LC|PBL|CE|PBL|LC). Electrochemical testing involved impedance spectroscopy measurements in air in the 500°C to 650°C range. Scanning electron microscopy combined with energy‐dispersive X‐ray spectroscopy (SEM/EDS) revealed that distinct PBLs possess uneven wetting tendency, with impact on the role of LC layers. The best electrode performance (0.55 Ω cm2 electrode area specific resistance at 550°C in air) was observed using the LN37 PBL, stable throughout endurance tests up to 200 hours. Possible electrode mechanisms consistent with experimental evidence suggest an active role of the molten phase as an intermediate provider of O2− transport between the electrode and CGO. [ABSTRACT FROM AUTHOR]

Summary: Graphene‐based electrodes have great potential for using as positive electrode material of vanadium redox flow batteries. However, production of heteroatom doped graphene oxide in classical methods had many steps and time‐consuming procedure. In this work, binder‐free sulfur‐doped graphene oxide electrodes (S‐GOEs) were obtained from graphite by the chronoamperometric method in eco‐friendly media (sulphuric acid/water) and one step at room temperature. The effects of functional groups ratio on the positive electrolyte performance of vanadium redox battery was investigated via electrochemical methods such as cyclic voltammetry (CV), chrono charge‐discharge, and electrochemical impedance spectroscopy (EIS). Microscopic methods were also used for investigation of the surface morphology of the modified electrodes. Detailed chemical composition of modified electrodes surfaces was investigated by X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR‐ATR) spectroscopy and energy‐dispersive X‐ray spectroscopy (EDS) techniques. CSOxC(x = 2, 3), CSO, hydroxyl, carboxyl and epoxy groups were formed on the modified electrodes during the preparation of graphene oxide based electrodes from the graphite. According to cyclic voltammetry analysis, the electrodes prepared over 3 minutes by chronoamperometric method at 1.9 V (S‐GOE3) showed the best performance as a positive electrode of the vanadium redox battery. The cyclic charge‐discharge test demonstrated that the discharge capacity considerably increased from 171.9 mA h to 179 mA h at 3.2 mA cm−2 discharge current density. Energy efficiency of cell was also climbing by 5% in S‐GOE3 as positive electrode to bare electrode. [ABSTRACT FROM AUTHOR]

Summary The development of an efficient water electrolyser is essential for sustainable hydrogen production; however, its application remains limited by the insufficient performance of the electrode. Herein, we report a rapid, simple, and cost‐effective fabrication of an Ni‐Co‐S cathode for the hydrogen evolution reaction (HER), which is directly usable for an anion exchange membrane water electrolyser (AEMWE). The Ni‐Co‐S electrocatalysts are prepared on a carbon paper (CP) substrate by a one‐step electrodeposition method by controlling deposition parameters such as the deposition potential, time, and electrolyte composition. The optimized Ni‐Co‐S/CP electrode demonstrates a high HER activity with an overpotential of 91 mV at −10 mA/cm2 in 1.0 M KOH. An AEMWE single cell employing the Ni‐Co‐S/CP cathode coupled with a commercial IrO2/CP anode exhibits a current density of 1.7 A/cm2 at 2.4 Vcell, which is higher than that of an AEMWE single cell with a commercial Pt/C/CP cathode; this is attributable to the enhancement of the electron and reactant/product transfer via appropriate cathode design. [ABSTRACT FROM AUTHOR]

Summary: In present study, zinc oxide/zinc sulfide (ZnO/ZnS) nanostructures were fabricated by anodization of Zn. The morphological, structural and compositional properties of ZnO/ZnS were studied by field emission scanning electron microscopy (FESEM) and X‐ray diffraction (XRD). From FESEM results, well‐defined and smooth spherical‐like ZnO/ZnS nanostructures were obtained with tube‐like ZnO nanostructures underneath the compact layer. XRD patterns revealed that achieved materials offer high crystallinity hexagonal ZnO as dominant with hexagonal close‐packed polycrystalline Zn. Moreover, measure of water contact angle was realized to learn about wetting property of the electrodes. Electrochemical impedance spectroscopy (EIS) was recorded to examine electrocatalytic performance of electrodes against hydrogen evolution reaction (HER) in 1 M KOH solution. The values of energy consumption and energy efficiency were calculated as 571.9 kJ mol−1 and 49.5% at current density of 50 mA cm−2 for the HER on 40‐ZnO/ZnS/Zn electrode at 25°C. [ABSTRACT FROM AUTHOR]

Summary: Microbial fuel cells (MFCs) are bioelectrochemical transducers that can be used to produce electrical power under the activity of microbes during the wastewater treatment processes. In the present study, the electrode spacing was considered as a parameter to investigate the influence on the performance of MFCs. The electrode spacing was defined as the distance of the anode electrode plate to the polymer exchange membrane in the MFCs. Three values were set at 0.0, 3.0, and 6.0 cm, respectively. In addition, a flow device, like a honeycomb type flow straightener, was introduced and implemented in the anode chamber for creating a uniform flow. The inner diameter of the honeycomb was 0.7 cm. Results showed that a higher limiting current density with 4108.7 mA/m2 and a lower resistance with 2.51 Ω can be found in the case of the 0.0 cm electrode spacing. These results also indicated that the shorter electrode spacing with flow straightener devices would improve the performance of MFCs, leading to lower internal resistance and higher power density. In addition, the scanning electron microscopy was employed to analyze the biofilm thickness for MFCs with different electrode spacing. It was also found that the biofilm thickness with 0 cm electrode spacing was larger than the other two cases, leading to a lower internal resistance in the MFCs. [ABSTRACT FROM AUTHOR]

Summary: The study deals with the modification of commercial Ni/GDC powder with iron and its use as fuel functional electrode for Solid Oxide H2O electrolysis. The Fe‐NiO/GDC samples were prepared with the Deposition‐Precipitation method and characterized, in their oxidized and reduced form, by using BET, HR‐TEM, SAED, XRD, XPS and TG analysis in the presence of H2O. The electrochemical investigation deals with the comparison of single SOECs at 900°C, under various pH2O/pH2 ratios. In the oxidized powders iron was detected, both in the bulk and on the surface, in the form of crystallized Fe2O3 species, which during H2‐reduction interacted with NiO towards the formation of a Ni‐Fe alloy. The latter promoted the electrochemical performance of the Fe‐Ni/GDC electrodes, where there are indications of strong dependence on the Fe wt% content. Specifically, the performance of the cell with 0.5 wt% Fe‐Ni/GDC was threefold higher than that with Ni/GDC. On the other hand, the cell with 2 wt% Fe‐Ni/GDC was worse, implying that the promoting effect of Fe lies on quite low wt% content. Finally, the examined Fe‐doped electrodes exhibited increase of polarization in high pH2O. This is primarily ascribed to the fact that Fe‐Ni/GDC electrodes seem more susceptible to H2O oxidation. Overall, Fe is considered as a promising Ni/GDC dopant, capable to substitute noble metals like Au, but further investigation is required for the elucidation of key preparation and performance parameters. [ABSTRACT FROM AUTHOR]

Summary: Solid oxide fuel cell (SOFC) is known as the most efficient fuel cell, with an efficiency of 60% in converting fuel to electricity and up to 80% in fuel to energy conversion (including heat). A SOFC consists of three primary components, namely, anode, electrolyte and cathode. Given the demand for reducing the operating temperature below 800°C, not only thin electrolytes have become a necessity for their ability to reduce ohmic losses but also high‐quality porous electrode (anode and cathode) films for their ability to accelerate electrochemical reactions with fuels. In this context, screen printing is known for its capability to form high‐quality porous electrode films in a cost‐effective manner. In addition, screen printing offers fabrication‐related parameters that can be easily manipulated to produce different film qualities depending on the requirements which have been explored in various applications. However, screen printing is only utilised in SOFC application as a fabrication tool to produce electrode films, neglecting the effects of its fabrication‐related parameters on electrode performance, as indicated by the limited number of related works. Despite limited resources, this study aims to review the fabrication‐related parameters in producing SOFC electrodes through screen printing and their effects on electrochemical performance. The parameters at different stages (ie, prior, during and post printing), including ink formation, printing numbers and sintering, are extensively reviewed. To the best of our knowledge, this study is not only the first review that discusses the effects of screen‐printing fabrication‐related parameters on electrode potentials but also offers suggestions on future directions regarding these parameters towards the improvement of SOFC performance. Novelty Statement: Among all thin‐film fabrication methods, screen printing is known for its capability to form homogenous‐porous SOFC electrode films; however, the processing parameters of screen printing at three primary stages (prior, during, and postprinting) are rarely explored. As such, the current paper highlights important parameters in screen printing, such as ink rheology, printing number, and sintering, to contribute to the understanding of the influence of these parameters on SOFC electrode film quality and their effects on electrochemical performance. [ABSTRACT FROM AUTHOR]

Summary: Nitrogen‐doped porous carbon nanoribbons (NPCNs) are facilely prepared by carbonization of polypyrrole (PPy) nanotubes followed by a chemical activation process. NPCN counter electrodes are subsequently fabricated by depositing NPCNs onto Ti mesh for quantum dot‐sensitized solar cells (QDSCs). Electrochemical tests are carried out to evaluate the electrocatalytic performance of obtained NPCN electrode. The data of electrochemical tests suggest that the NPCN electrode has a superior electrocatalytic ability towards polysulfide (S22−/S2−) electrolyte regeneration reaction and displays a high stability in polysulfide electrolyte. The excellent electrocatalytic performance of NPCN electrode can be ascribed to their large surface area, 2D porous nanoribbon morphology, and nitrogen atom doping, which provides abundant electrocatalytic active sites and facilitates the electrolyte diffusion. Consequently, a power conversion efficiency of 3.27% is obtained by using NPCN electrode as the counter electrode for QDSC. This efficiency is close to the QDSC assembled with commonly used PbS electrode (4.0%). [ABSTRACT FROM AUTHOR]

Summary: The effect of 8.0 MeV carbon ions (C++) radiations on features and performances of MnO2–NiO–ZnO@GO electrodes (thin films). MnO2–NiO–ZnO@GO thin films were produced using the hydrothermal technique. 8.0 MeV carbon ions (C++) with doses of 2.25 × 1015, 5.0 × 1015, 7.5 × 1015 and 1.0 × 1016 ions/cm2 were irradiated on MnO2–NiO–ZnO@GO thin films. The XRD spectra indicate crystalline nature of the films while SEM images show rod‐like structures. The XRD calculated crystallite sizes varied from 1.24 to 5.58 nm. Energy‐dispersive X‐ray spectroscopy, Proton induced X‐ray emission (PIXE) and Rutherford back scattering (RBS) analysis are used to evaluate the elemental compositions of samples. Optical studies show reduced bandgap energies of various oxides due to the addition of graphene oxide. The electrochemical studies obtained a specific capacitance of 1627 and 1960 F/g for electrodes illuminated with radiation doses of 5.0 × 1015 and 7.5 × 1015 ions/cm2, respectively. Results indicate that carbon ion irradiation with low doses improved the performances of the nanostructured thin films while radiation with high doses induces adverse disorder and flaw to the MnO2–NiO–ZnO@GO thin film properties. These results show that ion beam irradiation is a useful tool to enhance or damage the properties of nanostructured materials depending on the dosages radiation beamed on the material. [ABSTRACT FROM AUTHOR]

Summary: Electrocatalytical conversion of CO2 into various chemicals like hydrocarbons and CO is regarded as a promising approach to mitigate carbon emission and, meanwhile, to provide sustainable energy and value‐added chemicals. Two different reactors are used in this work. One is based upon the two‐electrode configuration powered by a DC power supply or Si solar cell, which is suitable for practical applications. Another is three‐electrode one powered by a potentiostat, which is feasible to study the electrode performance. Polycrystalline Cu electrode is used as the cathode, and hematite is the anode. Performance of CO2 reduction using the two‐ and three‐electrode configurations is studied by measuring electrode potential, cell voltage, current density, Faradaic efficiency, and reduction selectivity of CO2. Cu cathode used here exhibits a low overpotential for CO2 reduction, specifically for the cell with two‐electrode configuration. No obvious difference can be observed between the two types of configurations at a low bias like −0.3 and −0.4 V; while the reactor with two‐electrode configuration exhibits better performance at a high bias like −0.8 V than the one with three‐electrode configuration. Thus, the reactors with two‐electrode configuration are desirable for practical applications, specifically considering solar cells can be used as the power source to provide green and sustainable energy. [ABSTRACT FROM AUTHOR]

Summary: Compared with symmetric supercapacitors, asymmetric supercapacitors are been widely applied in energy storage devices because of delivering an impressible energy density. Herein, a simple temple strategy was used to fabricate the porous hollow carbon spheres (PHCS) with high specific surface area of 793 m2 g−1, large pore volume of 1.0 cm3 g−1 and pore size distribution from micropores to mesopores, serving as the capacitive electrodes of asymmetric supercapacitors. Subsequently, manganese dioxide (MnO2) was impregnated into the PHCS to form a faradic electrode with a promising performance, owing to a synergistic effect between high capacity MnO2 and conductive PHCS. Furthermore, the flexible asymmetric solid‐state devices were constructed with PHCS anode, PHCS@MnO2 cathode, and PVA/LiCl electrolyte, extending a voltage window up to 1.8 V. The extensive voltage window would lead to an increased energy density. In our case, the flexible asymmetric sandwich exhibit excellent electrochemical performance in terms of a high energy density capacity of 26.5 W·h kg−1 (900 W kg−1) and superior cycling performance (10 000 cycles). Therefore, the developed strategy provides a strategy to achieve the PHCS‐based composites for the application in the asymmetric solid‐state supercapacitors, which will enable a widely field of flexible energy storage devices. [ABSTRACT FROM AUTHOR]

Summary: A hydrogen ion supercapacitor cell was constructed with an electrochemical double‐layer carbon material as positive electrode and an electrochemical hydrogen storage composite material as negative electrode. The electrochemical performances of both electrodes and hybrid device were investigated by varying of the mass ratio of positive and negative electrode. It was found to be that both electrodes went through the different hydrogen ion storage processes and the capacity of this hybrid supercapacitor was highly correlated with the negative to the positive electrode ratio. The highest capacity was achieved at ratio of 1:7; further increasing of this ratio may downgrade the performance of the hybrid system. With this optimized ratio, the hybrid device demonstrated good electrochemical performance. Novelty Statement: A new hybrid supercapacitor is developed using an electrochemical hydrogen storage cobalt/carbon composite material as negative electrode and a double‐layer porous carbon material as positive electrode. In this device, the charge carrier is hydrogen ions generated through the electrolysis of the aqueous electrolyte and, like lithium ion supercapacitor, the H ions rock‐chaired between positive and negative electrode during the operation. The structure of this new device is engineered, and the energy storage and conversion mechanisms on both electrodes during the operation are also discussed. [ABSTRACT FROM AUTHOR]

Summary: Traditional three‐dimensional (3D) graphene has a large pore structure, which makes the graphene structure not well interact with the anion and cation during the desalination process, thereby restricting the capacitive deionization (CDI) ability of the 3D graphene. In this work, we prepared a nitrogen‐doped self‐shrinking porous 3D graphene electrode by adding a pyrrole monomer to a graphene oxide solution, which was then applied to a CDI electrode. The results show that the electrochemical performance of the as‐prepared nitrogen‐doped self‐shrinking porous 3D graphene (NSPG) is significantly improved. Compared with traditional 3D graphene, NSPG has a denser pore structure with a larger specific surface area, thus exhibiting a good CDI performance: The NSPG electrode has an electroadsorption capacity of 13.16 mg/g. [ABSTRACT FROM AUTHOR]

Summary: Lithium‐rich layered oxides (LRLOs) are highly attractive cathode materials for next‐generation lithium‐ion batteries because of their high reversible capacity, but poor cycle performance and voltage decay are two main problems that strongly limit their practical applications. These challenges also apply to the Ru‐based LRLOs of Li2RuO3. The Li2RuO3 cathode material is highly attractive because of their high conductivity and favourable electrochemical reaction kinetics. To overcome the problems associated with Li2RuO3, in contrast to normal single atom doping, here, we propose a Na, Cr co‐doping strategy with the design of Li2−xNaxRu0.95Cr0.05O3 (x = 0, 0.02, 0.06, and 0.1) series materials. Cr doping increases capacity, and Na doping suppresses voltage decay. As a result, the discharge capacity of the optimal Li1.98Na0.02Ru0.95Cr0.05O3 sample over 240 mAh/g after 50 charge‐discharge cycles at 0.2 C is maintained, and the capacity retention reaches a value of 80.5% compared with 69.1% for the undoped Li2RuO3. The value of the voltage decay in the Li1.98Na0.02Ru0.95Cr0.05O3 sample is 125 mV after 100 cycles at a rate of 1 C, and the voltage decay is 188.4 mV for the undoped Li2RuO3. This finding will expand the scope for designing novel layered electrodes with excellent performance. [ABSTRACT FROM AUTHOR]

Summary: Three‐dimensional microstructure of infiltrated solid oxide fuel cell electrodes with dual‐phase backbone is simulated numerically. This work employs LSM (lanthanum strontium manganite) infiltrated LSM yttria‐stabilized zirconia composite electrodes as an example. Important geometric properties, including percolation probability of LSM, total and percolated three‐phase boundary (TPB) lengths, and total and percolated surface areas of LSM, are calculated under various LSM nanoparticle loadings. One important finding is that compared with pure yttria‐stabilized zirconia backbone, dual‐phase backbone results in lower TPB length and has little impact on the surface area of LSM particles. Therefore, the addition of LSM backbone may be ineffective, even negative in promoting the electrode performance, however, can significantly reduce the LSM infiltration threshold loading to form a percolating network. The trade‐off between decreasing infiltration cycle and increasing TPB length demands an optimized content of LSM in backbone. [ABSTRACT FROM AUTHOR]