Stability Of Electrode Research Articles

Constructing a stable and high-performance counter electrode for QDSSCs by modifying Co3S4 hollow nanocages with CuCo–B alloy-nanosheets

Counter electrode (CE) is a key part of enhancing power conversion efficiency (PCE) and strengthening cyclic stability in quantum dot sensitized solar cells (QDSSCs). Consequently, searching for alternative and high-quality CE materials has far-reaching consequences for extending the lifetime, increasing utilization and even further achieving commercialization of QDSSCs. Herein, we put forward an idea that the Co3S4 hollow nanocages were coated with CuCo–B alloy-nanosheets, and efficient Co3S4@CuCo–B composite CE was prepared by in-situ reduction method, and applied to QDSSCs. Because of its three-dimensional hollow structure, the Co3S4@CuCo–B composite has a higher specific surface area, encourages electrolyte diffusion, and enhances QDSSC stability. Alternatively, the work function analysis shows that Co3S4 modified by CuCo–B enhances the driving force of interfacial electric field and promotes electron transfer. The photovoltaic performance of QDSSC assembled with Co3S4@CuCo–B composite CE has demonstrated competitive ability via implementing a PCE up to 8.27 %, Jsc = 26.45 mA cm−2, Voc = 0.683 V and FF = 0.46. Among them, the PCE of Co3S4@CuCo–B composite CE respectively has ∼14.4 % and 29.6 % enhancements in comparison with pure CuCo–B and Co3S4 CEs. And Co3S4@CuCo–B composite CE displays stable current density after 200 cycle tests, demonstrating excellent cyclic stability. This work suggests that Co3S4@CuCo–B composite lays the theoretical foundation for becoming a high-performance CE.

Unraveling the impact of reverse currents on electrode stability in anion exchange membrane water electrolysis

Anion Exchange Membrane Water Electrolysis (AEMWE) stands out as one of the promising ways of producing green hydrogen. However, significant strides in performance and durability are necessary for commercial competitiveness. Shunt currents and reverse currents are common problems associated with electrolyzers using conductive liquid electrolytes during start/stop conditions and can enhance electrode degradation. This study incorporates a dual Pt-wire reference electrode within the flow cell consisting of a NiFe-layered double hydroxide anode and different cathode materials to decouple individual electrode kinetics under steady state and intermittent operating conditions. The performance of bimetallic cathode catalysts like PtRu/C and NiMo/C was assessed in comparison with traditional Pt/C catalysts in the context of the hydrogen evolution reaction. The initial observed catalyst activity displayed an evident trend in the order of PtRu/C > Pt/C > NiMo/C. When subjected to reverse currents, all three systems showed degradation in performance. The use of reference electrodes illustrated that all cathode coatings degraded as a result of the reverse currents while the anode remained relatively stable. The degradation followed the trend of NiMo/C > PtRu/C > Pt/C. This work thus shows that reverse currents are a real issue for AEMWE and demonstrates the importance of investigating electrodes under intermittent conditions.

3D Bismuth@N-Doped carbon microflowers for ultrahigh rate and stable sodium storage

Sodium-ion batteries (SIBs) are gaining attention in the energy storage market due to their high theoretical capacity and affordability. However, challenges such as volume expansion and sluggish dynamics during sodiation/desodiation hinder their practical application. A 3D bismuth@N-doped carbon microflowers (Bi@NC) anode was successfully prepared to address these issues. The Bi nanosheets expedite Na ions and electrons transport and inhibit particle pulverization, while the N-doped carbon layer maintains electrode stability and improves electronic conductivity. The Bi@NC anode exhibits ultrahigh rate (336.7 mAh/g at 20 A/g) and stable performance (92.9% capacity retention after 2500 cycles at 5 A/g).

Stable and reliable bio-interfacing electrodes based on conductive hydrogels

Stable and reliable bio-interfacing electrodes based on conductive hydrogels

Nanostructured MoS2 grafted by anthraquinone for energy storage

Two-dimensional materials such as molybdenum disulfide (MoS2) can be employed as an electrode material in energy systems due its good electrical conductivity and high reachable capacity/capacitance. We demonstrate the concept of a covalent modification of nanostructured MoS2 with anthraquinone (AQ) molecules through diazonium salt chemistry for electrochemical capacitors and lithium-ion storage. AQ molecules are chemically bonded to MoS2 which was proved experimentally by spectroscopic techniques. Here, AQ is grafted (ca. 20 wt%) to the outer surface of nanostructured MoS2, but also confined within the MoS2 interlayer spacing. Modified AQ-MoS2 exhibited faradaic response which improved the overall charge stored from 191 F g−1 (461 F cm−3) to 263 F g−1 (631 F cm−3) at 0.2 A g−1 in 1 M H2SO4. The process of intercalation of ions within interlayer spacing of AQ-MoS2 was not hindered by the presence of confined AQ molecules. Impedance spectroscopy and voltammetry analysis revealed comparable non-diffusion limited response of MoS2 before and after modification. The MoS2 modification was likely conducted on the defect sites limiting the catalytic activity of MoS2 towards hydrogen evolution improving stability of electrodes. In organic medium, the pseudocapacitive response of MoS2, enhanced by additional redox reactions of grafted AQ was observed during lithium-ion storage.

Design of Solid Polycationic Electrolyte to Enable Durable Chloride‐Ion Batteries

AbstractThe high energy density and cost‐effectiveness of chloride‐ion batteries (CIBs) make them promising alternatives to lithium‐ion batteries. However, the development of CIBs is greatly restricted by the lack of compatible electrolytes to support cost‐effective anodes. Herein, we present a rationally designed solid polycationic electrolyte (SPE) to enable room‐temperature chloride‐ion batteries utilizing aluminum (Al) metal as an anode. This SPE endows the CIB configuration with improved air stability and safety (i.e. free of flammability and liquid leakage). A high ionic conductivity (1.3×10−2 S cm−1 at 25 °C) has been achieved by the well‐tailored coordination structure of the SPE. Meanwhile, the solid polycationic electrolyte ensures stable electrodes|electrolyte interfaces, which effectively inhibit the growth of dendrites on the Al anodes and degradation of the FeOCl cathodes. The Al|SPE|FeOCl chloride‐ion batteries showcased a high discharge capacity around 250 mAh g−1 (based on the cathodes) and extended lifespan. Our electrolyte design opens a new avenue for developing low‐cost chloride‐ion batteries.

Design of Solid Polycationic Electrolyte to Enable Durable Chloride-Ion Batteries.

The high energy density and cost-effectiveness of chloride-ion batteries (CIBs) make them promising alternatives to lithium-ion batteries. However, the development of CIBs is greatly restricted by the lack of compatible electrolytes to support cost-effective anodes. Herein, we present a rationally designed solid polycationic electrolyte (SPE) to enable room-temperature chloride-ion batteries utilizing aluminum (Al) metal as an anode. This SPE endows the CIB configuration with improved air stability and safety (i.e. free of flammability and liquid leakage). A high ionic conductivity (1.3×10-2 S cm-1 at 25 °C) has been achieved by the well-tailored coordination structure of the SPE. Meanwhile, the solid polycationic electrolyte ensures stable electrodes|electrolyte interfaces, which effectively inhibit the growth of dendrites on the Al anodes and degradation of the FeOCl cathodes. The Al|SPE|FeOCl chloride-ion batteries showcased a high discharge capacity around 250 mAh g-1 (based on the cathodes) and extended lifespan. Our electrolyte design opens a new avenue for developing low-cost chloride-ion batteries.

Superior stable high‐voltage LiCoO2 enabled by modification with a layer of lithiated polyvinylidene fluoride‐derived LiF

AbstractHigh‐voltage LiCoO2 (LCO) can deliver a high capacity and therefore significantly boost the energy density of Li‐ion batteries (LIBs). However, its cyclability is still a major problem in terms of commercial applications. Herein, we propose a simple but effective method to greatly improve the high‐voltage cyclability of an LCO cathode by constructing a surface LiF modification layer via pyrolysis of the lithiated polyvinylidene fluoride (Li‐PVDF) coating under air atmosphere. Benefitting from the good film‐forming and strong adhesion ability of Li‐PVDF, the thus‐obtained LiF layer is uniform, dense, and conformal; therefore, it is capable of acting as a barrier layer to effectively protect the LCO surface from direct exposure to the electrolyte, thus suppressing the interfacial side reactions and surface structure deterioration. Consequently, the high‐voltage stability of the LCO electrode is significantly enhanced. Under a high charge cutoff voltage of 4.6 V, the LiF‐modified LCO (LiF@LCO) cathode demonstrates a high capacity of 201 mA h g−1 at 0.1 C and a stable cycling performance at 0.5 C with 80.5% capacity retention after 700 cycles, outperforming the vast majority of high‐voltage LCO cathodes reported so far.

Production and New Green Activation of Conductive 3D-Printed Cu/PLA Electrode: Its Performance in Hydrogen Evolution Reactions in Alkaline Media

In this study, Cu-polylactic acid (PLA) composite filaments were produced with an extruder and three-dimensional (3D) Cu/PLA electrodes were 3D printed with Fused Deposition Modelling (FDM) method. To improve the electrochemical performance of the 3D-Cu/PLA electrode, a novel electrochemical activation method, which differentiates from complex activation methods in the literature, was applied in 1 M KOH solution without using any solvent. Field emission scanning electron microscopy (FE-SEM), Energy-Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FT-IR), and RAMAN techniques were used to characterize the 3D-Cu/PLA electrode before and after activation. The results showed that Cu particles were released after the degradation of PLA after activation. In addition, the thermal stability of the 3D electrode was demonstrated by the TGA technique. The performance of the 3D Cu/PLA electrode before and after activation in the hydrogen evolution reaction (HER) in 1M solution was measured using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and cathodic polarization curves methods. The EIS results showed that the charge transfers resistance values of the 3D-Cu/PLA electrode in 1 M KOH decreased significantly after activation. Post-activation hydrogen content measurements of the 3D-Cu/PLA electrode after electrolysis at different potentials and energy efficiency tests at different current densities were also carried out. The results indicate that the electrocatalytic properties of 3D-Cu electrodes were improved for HER through the activation process.

Effects of foam cathode electrode structure on alkaline water electrolysis for hydrogen production

Hydrogen is widely recognized as a clean and sustainable energy source. One of the most promising methods for hydrogen production is alkaline water electrolysis. The efficiency and cost-effectiveness of this process heavily depend on the choice of a suitable porous electrode structure. This paper aims to investigate impact of the porous structure on the performance of alkaline electrolytic water through experiments and multi-physics field simulation. Specifically, the whole cell performance test and hydrogen-evolution reaction (HER) test of nickel foam were conducted in an electrolytic cell using 1 M KOH. Results revealed that various parameters of the electrode structure, such as specific surface area, pore density, thickness, and electronic conductivity, significantly influenced the hydrogen evolution. Increasing the specific surface area or pore density proved to enhance the hydrogen evolution under conventional voltage. Reducing the thickness has a similar effect. Additionally, materials with high conductivities increase the reaction rate. Based on experimental results, the optimal nickel foam cathode structure was 1000 μm thickness and 75 PPI pore density. The results of stability tests and electrolysis voltage efficiency analysis provide further support for the positive effect of this structure on hydrogen evolution. This study provides rational reference for designing efficient and stable porous electrode structures.

Constructing stable electrode–electrolyte interfaces by sulfone-based additive to improve the high-voltage performance of LiCoO2

LiCoO2 battery can provide high reversible capacity at a high voltage of 4.6 V, however, maintaining its stability at high voltages remains a major challenge. To address this issue, ethyl methyl sulfone (EMS) is employed as an electrolyte additive to construct stable interfaces between the electrode and electrolyte under high-voltage condition. The characterization results indicate that the addition of EMS can inhibit the decomposition of the standard electrolyte (STD) and the dissolution of Co2+ from cathode, as well as the formation of lithium dendrites on the Li anode, thereby enhancing the stability of both cathode/electrolyte and anode/electrolyte interfaces. Consequently, the cycling performance of LiCoO2 battery using STD+3 %EMS is augmented by 16.9 % at 1 C under a cut-off voltage of 4.6 V over 100 cycles, delivering a specific capacity of 137 mA h g−1. This research provides novel insights into the design of electrolyte additives for high-voltage LiCoO2 batteries and contributes to the further development of high-voltage lithium-ion batteries.

Electrochemical degradation of carbamazepine in water by a flow-through and pilot-scale reactor with carbon felt electrodes: Parametric study under realistic operational conditions

Carbamazepine (CBZ) is one of the most stable pharmaceutical compounds that is commonly found in the effluents of wastewater treatment plants (WWTP). In this context, this contribution presents a comprehensive analysis of the different operating parameters of a flow-through and pilot-scale cylindrical reactor for hydrogen peroxide (H2O2) generation, in which the degradation of CBZ takes place. The electrochemical system was evaluated using 8 L of electrolytes prepared with tap water in the presence of methanol as dissolved organic matter or spiked tertiary WWTP effluent, at a volumetric flow of 7 L min−1. This reactor (i) improves the mass transport due to its flow-through configuration using fibrous quasi-three-dimensional carbon felt electrodes, (ii) operates without an external oxygen supply to promote the H2O2 electrosynthesis because it is incorporated by a jet aerator (iii) achieves the Fenton reaction at circumneutral pH due to Fe(II) disposition from a cation exchange resin. At first, the carbonaceous materials were electrochemically characterized by cyclic voltammetry measurements. Different operating parameters were evaluated by factorial design methodologies for H2O2 generation, energetic consumption and CBZ removal. The application of a current density of 1.4 mA cm−2, in a cathode-anode-cathode arrangement immersed in a 120 mM ionic strength solution, allowed to obtain up to 6.4 mg H2O2 L−1 after 40 min, consuming 0.44 kWh m−3. Later, the Fenton reaction was validated by a florescence study, and by the incorporation of 0.75 g of granular activated carbon and 5 g of Fe(II) loaded resin, CBZ abatement yields of 68 % and 32 % were obtained using a synthetic solution and a spiked tertiary WWTP effluent, respectively, and up to 28 % of the dissolved total organic carbon was removed. Finally, an analysis of the stability of the carbon felt electrodes was tackled using scanning electron microscopy and energy-dispersive X-ray spectroscopy.

P‐108: High conductivity transparent electrode with In2O3 – ZnO periodic structure and gradient oxygen concentration

Multilayer structures based on the In‐Zn‐O (IZO) system with modulated oxygen doping have been developed as a TCF (transparent conductive film) alternative to ITO or IGZO layers in the LC and OLED displays. The minimum resistivity (3.37 Ohm*cm) and the maximum concentration of free charge carriers correspond to the layers synthesized in an atmosphere of pure argon, while the maximum mobility (39.18 cm2/V*s) corresponds to the layers synthesized in the atmosphere of both argon and oxygen 99.6%/0.4% mixture. Thin‐film periodic structures with gradient modulation of oxygen content in thickness have been fabricated by periodically changing the oxygen concentration in the composition of the working gas during spraying at a substrate temperature of 100 °C. The structures consist of alternating layers with a high concentration of free charge carriers and layers with high mobility. As a result of the single layers' thicknesses optimization the thin‐film periodic structures with a minimum resistivity of 2.89 Ohm*cm have been made. The resistivity is lower than in homogeneous layers of the same composition. The alternation of layers of optimal thickness provides high carrier mobility, it is inherent to layers synthesized in the atmosphere of 99.6/0.4 argon and oxygen mixture at high concentration. The mobility value is close to the value achieved in the layers synthesized in the pure argon atmosphere.This material provides fabrication of high quality, stable and low cost transparent electrodes or TFT layers with performances corresponding to parameters of traditional materials.

Sputter Deposited Crystalline MoO2 Films as a High-Capacity and Stable Electrode Material for Supercapacitors: Mechanistic/Electrochemical Insights

In this work, we have optimized and fabricated pristine molybdenum dioxide (MoO2) electrodes over the Silicon (Si) substrate and examined the impact of various ion-loaded aqueous electrolytes on their electrochemical behavior. The sputtered electrodes exhibited a high crystalline structure and a very low resistivity. These highly conductive electrodes were tested in three different aqueous electrolytes (acidic, neutral, and alkaline) to establish a relation between the electrode and the nature of the electrolyte to achieve optimal electrochemical performance and cyclability. The electrochemical kinetics showed that the charge storage mechanism was unique for all the electrolytes. The capacitive current was dominant in the neutral electrolyte, whereas it was diffusive dominant in alkaline and 70% capacitive in the acidic electrolyte. Our findings indicated that the MoO2@Si electrode exhibited superior electrochemical activity in an acidic electrolyte. The electrode showed a voltage window of 0.6 V with an areal capacity of 24 mF/cm2 at 0.1 V/s scan rate. Moreover, the electrode also demonstrated excellent cyclability and capacitance retention (∼145%) till 5000 cycles. These results highlighted that the binder-free MoO2@Si electrode showed outstanding electrochemical activity and stability, which makes it suitable for sulfuric acid electrolyte-based energy storage systems.

Gadolinium-doped SrFeO3 as a highly active and stable electrode for symmetrical solid oxide fuel cells

Symmetrical solid oxide fuel cells (SSOFCs) with identical electrodes have gained interesting attention because of their simplified fabrication procedure and reduced processing costs. However, their development is limited by their electrocatalytic activity and stability of the electrode materials used. Here, we report a prototypical SrFeO3-δ-based perovskite oxide with formula GdxSr1-xFeO3-δ (GSF) as a highly effective SSOFC electrode material. It was found that A-site Gd substitution in SrFeO3-δ greatly improved its structural stability under reducing atmosphere. Furthermore, doping Gd was able to significantly enhance the electrochemical activity, achieving area-specific resistances of 0.18 Ω cm2 for the cathode and 0.003 Ω cm2 for the anode at 800 °C, respectively. The lower polarization resistance could be attributed to the abundant surface oxygen species through the Gd-doping in SrFeO3-δ. Benefiting from superior electrochemical activity and structural stability, the symmetrical cell with GSF-0.2 electrode showed reasonable stability and electrochemical performance. These results show that the developed GSF perovskite oxide may be a promising candidate as electrode material for symmetrical SOFCs.

Unique Self-Phosphorylating Polybenzimidazole of the 6F Family for HT-PEM Fuel Cell Application.

High-temperature polymer-electrolyte membrane fuel cells (HT-PEMFCs) are a very important type of fuel cells since they operate at 150-200 °C, making it possible to use hydrogen contaminated with CO. However, the need to improve the stability and other properties of gas-diffusion electrodes still impedes their distribution. Self-supporting anodes based on carbon nanofibers (CNF) are prepared using the electrospinning method from a polyacrylonitrile solution containing zirconium salt, followed by pyrolysis. After the deposition of Pt nanoparticles on the CNF surface, the composite anodes are obtained. A new self-phosphorylating polybenzimidazole of the 6F family is applied to the Pt/CNF surface to improve the triple-phase boundary, gas transport, and proton conductivity of the anode. This polymer coating ensures a continuous interface between the anode and proton-conducting membrane. The polymer is investigated using CO2 adsorption, TGA, DTA, FTIR, GPC, and gas permeability measurements. The anodes are studied using SEM, HAADF STEM, and CV. The operation of the membrane-electrode assembly in the H2/air HT-PEMFC shows that the application of the new PBI of the 6F family with good gas permeability as a coating for the CNF anodes results in an enhancement of HT-PEMFC performance, reaching 500 mW/cm2 at 1.3 A/cm2 (at 180 °C), compared with the previously studied PBI-O-PhT-P polymer.

Non-flammable long chain phosphate ester based electrolyte via competitive solventized structures for high-performance lithium metal batteries

Safety remains a persistent challenge for high-energy–density lithium metal batteries (LMBs). The development of safe and non-flammable electrolytes is especially important in harsh conditions such as high temperatures. Herein, a flame-retardant, low-cost and thermally stable long chain phosphate ester based (tributyl phosphate, TBP) electrolyte is reported, which can effectively enhance the cycling stability of highly loaded high-nickel LMBs with high safety through co-solvation strategy. The interfacial compatibility between TBP and electrode is effectively improved using a short-chain ether (glycol dimethyl ether, DME), and a specially competitive solvation structure is further constructed using lithium borate difluorooxalate (LiDFOB) to form the stable and inorganic-rich electrode interphases. Benefiting from the presence of the cathode electrolyte interphase (CEI) and solid electrolyte interphase (SEI) enriched with LiF and LixPOyFz, the electrolyte demonstrates excellent cycling stability assembled using a 50 μm lithium foil anode in combination with a high loading NMC811 (15.4 mg cm−2) cathode, with 88% capacity retention after 120 cycles. Furthermore, the electrolyte exhibits excellent high-temperature characteristics when used in a 1-Ah pouch cell (N/P = 0.26), and higher thermal runaway temperature (238 °C) in the ARC (accelerating rate calorimeter) demonstrating high safety. This novel electrolyte adopts long-chain phosphate as the main solvent for the first time, and would provide a new idea for the development of extremely high safety and high-temperature electrolytes.

Molybdenum Sulfide Nanoflowers as Electrodes for Efficient and Scalable Lithium-Ion Capacitors.

Hybrid supercapacitors (HSCs) bridge the unique advantages of batteries and capacitors and are considered promising energy storage devices for hybrid vehicles and other electronic gadgets. Lithium-ion capacitors (LICs) have attained particular interest due to their higher energy and power density than traditional supercapacitor devices. The limited voltage window and the deterioration of anode materials upsurged the demand for efficient and stable electrode materials. Two-dimensional (2D) molybdenum sulfide (MoS2) is a promising candidate for developing efficient and durable LICs due to its wide lithiation potential and unique layer structure, enhancing charge storage efficiency. Modifying the extrinsic features, such as the dimensions and shape at the nanoscale, serves as a potential path to overcome the sluggish kinetics observed in the LICs. Herein, the MoS2 nanoflowers have been synthesized through a hydrothermal route. The developed LIC exhibited a specific capacitance of 202.4 F g-1 at 0.25 A g-1 and capacitance retention of >90 % over 5,000 cycles. Using an ether electrolyte improved the voltage window (2.0 V) and enhanced the stability performance. The ex-situ material characterization after the stability test reveals that the storage mechanism in MoS2-LICs is not diffusion-controlled. Instead, the fast surface redox reactions, especially intercalation/deintercalation of ions, are more prominent for charge storage.

Hierarchical carbon chain network ‘armor’ escorts long-term cycling stability for vanadium redox flow batteries

Nowadays, the bottleneck constraining the development of electrode materials for all-vanadium flow batteries lies in their poor performances at high current densities. Pertinently, we propose a high-stability hierarchical N and S co-doped carbon chain network ‘armor’ strategy to achieve long-term stability enhancement for electrodes. It is found that hierarchical carbon chain network can effectively enhance the voltage efficiency, energy efficiency, and long-term cycling stability for all-vanadium flow batteries. The modified electrode presents superior long-term stability over 1900 cycles, and the energy efficiency is maintained at about 80 % at 180 mA cm−2. In addition, the energy efficiency can also reach over 70 % at 320 mA cm−2, while at 280 mA cm−2 the modified electrode can circulate stably for over 800 turns. It is proved that the bridging effect of polydopamine facilitates the stable carbon chain network, and effectively regulates the N and S co-doping, further constructing the N and S co-doping sites to assemble electrochemical catalytic network. More importantly, the carbon chain network ‘armor’ design can effectively prevent electrode breakage. This work provides a reference way for the design of long-term stable electrodes, which is of great significance for advancing commercial applications of all-vanadium flow batteries.

Enhanced OER performance by varying Al-WO3 electrocatalyst thickness: Process optimization

Oxygen evolution reactions (OER) are highly significant and play a critical role in the advancement of fuel cells, electrolyzers, chemicals, and solar energy conversion devices. The challenge in the quest is attributed to the absence of an efficient electrocatalyst assembly that functions optimally. A simple method of electrodeposition of Al:WO3 on a fluorinated tin oxide (FTO) electrode was used to investigate the OER in this study. The electrodepositions were achieved by employing a three-electrode cell at various scan rates ranging from 10 to 100 mV/s. During this investigation, the influence of the scan rate on electrocatalyst loadings and the impact of electrocatalyst layer thickness on the OER were examined. The electrodepositions of Al:WO3@FTO were analyzed using a range of optical, chemical, and physical techniques such as SEM, XRD, FT-IR, Raman spectroscopy, EDX, EDS mapping, and electrochemical tests. The FTIR and Raman analysis confirmed the synthesis of AL:WO3 while the peaks detected at angles 38.7° and 43° by XRD with planes (111) and (200), served as a distinctive characteristic for identifying aluminum (Al). The peaks observed at angles of 27.8°, 30.7°, 33°, 50.45°, and 58° correspond to WO3 material. The characterization techniques also confirmed that the synthesized material is highly crystalline in nature. The OER potential using Al:WO3@FTO electrodes with different electrocatalyst thicknesses, ranging from 8 nm to 31 nm was investigated by studying various electrochemical techniques such as CV, LSV, CPE, Tafel slope, HP2P splitting, EIS, TOF, short and long-term electrode stability, and double layer capacitance. The linear regression coefficient (R2) was also calculated to measure the relationship between the electrocatalyst's thickness and each electrochemical test. The findings indicated that increasing the scan rates resulted in thinner and denser electrodepositions on the FTO substrate as the thinnest film was formed at 100 mV/s. An inverse relationship between electrocatalyst layer thickness and OER activity was observed. The electrode with the thinnest and most compact electrocatalyst layer, specifically ED Al:WO3@FTO08, exhibited the lowest onset potential of 1.48 V and a maximum current of 84 mA/cm2 at 1.76 V. It also demonstrated superior reaction kinetics, as evidenced by its lower Tafel slope value of 49 mV/dec, which is the lowest among all the electrodes that were prepared. In particular, the electrode with a thin and compact electrocatalyst layer worked better in OER operations than the other five electrodes that had higher amounts of Al:WO3.