Search Results (4,878)

The accelerating growth of the global population and the depletion of conventional energy resources have intensified the dual challenges of water scarcity and sustainable energy production. Microbial fuel cells (MFCs) have emerged as a promising bioelectrochemical technology capable of simultaneously treating wastewater and generating renewable electricity. Their performance is strongly dependent on electrode materials, particularly cathodes, which govern the kinetics of the oxygen reduction reaction (ORR) and overall energy conversion efficiency. Therefore, in order to improve the electro-kinetics of ORR, it is necessary to use catalysts with specific catalytic properties. An ideal catalyst for ORR must combine fast kinetics, high conductivity, high durability, and cost-effectiveness. Although platinum-based electrodes remain the most efficient ORR catalysts, their scarcity and prohibitive cost are hindering their commercialization. Therefore, research has focused on viable alternatives, such as metal oxides, perovskites, heterojunction composites, and emerging carbon-based materials, paving the way toward highly effective energy conversion and industrial-scale implementation of MFCs. Full article

High-temperature proton exchange membranes (HT-PEMs) are critical components of high-temperature fuel cells, facilitating proton transport and acting as a barrier to fuel and electrons; however, their performance is hampered by persistent issues of phosphoric acid leaching and oxidative degradation. Herein, a novel HT-PEM with abundant hydrogen bond network is constructed by incorporating nanoscale polyhedral oligomeric silsequioxane functionalized with eight pendent sulfhydryl groups (POSS-SH) into poly(4,4′-diphenylether-5,5′-bibenzimidazole) (OPBI) matrix. POSS, a cage-like nanostructured hybrid molecule, features a well-defined silica core and highly designable surface organic groups, offering unique potential for enhancing membrane performance at the molecular level. Through controlled reactions between sulfhydryl groups and allyl glycidyl ether (AGE), two functional POSS crosslinkers—octa-epoxide POSS (OE-POSS) and mixed sulfhydryl-epoxy POSS (POSS-S-E)—were synthesized. These were subsequently used to fabricate crosslinked OPBI membranes (OPBI-OE-POSS and OPBI-POSS-S-E) via epoxy–amine coupling. The OPBI-POSS-S-E membranes demonstrated exceptional oxidative stability, which is attributed to the free radical scavenging ability of the retained sulfhydryl groups on the nano-sized POSS framework. After soaking in Fenton’s reagent at 80 °C for 108 h, the OPBI-POSS-S-E-20% membrane retained 79.4% of its initial weight, significantly surpassing both the OPBI-OE-POSS-20% and pristine OPBI membranes. The PA-doped OPBI-POSS-S-E-20% membrane achieved a proton conductivity of 50.8 mS cm⁻¹ at 160 °C, and the corresponding membrane electrode assembly delivered a peak power density of 724 mW cm⁻², highlighting the key role of POSS as a nano-modifier in advancing HT-PEM performance. Full article

In this work, by employing NH₄F as a structure-directing agent (SDA) and VO(acac)₂, we have manipulated the morphology of Co₃O₄, leading to the creation of a novel hexagram-like structure with exceptional evenness in distribution. To comprehend the growth mechanism and elucidate the functions of various agents involved, experiments were conducted under diverse conditions with varying reagent ratios. The results indicate that, under the influence of NH₄F as the structure-directing agent (SDA), the hexagram-shaped Co₃O₄ structure exhibits sensitivity to both reaction time and temperature, implying that its growth mechanism is regulated by the Kirkendall effect and involves partial cation exchange. Additionally, with alteration of reagent ratios, Co₃O₄ with ball-flower morphology was synthesized successfully. Through cross-section SEM examination, the observed growth mechanisms for both the hexagram and ball-flower structures were substantiated. Lastly, electrochemical performance tests of the hexagram and ball-flower structures on SC electrode were carried out, and specific capacitances were 452 C/g (1062 F/g) and 696 C/g (1339 F/g), respectively. The hexagram-shaped Co₃O₄ structure displays exceptional SC electrode material characteristics, retaining an outstanding capacitance of 93.1% even after 10,000 cycles, highlighting its superior cycle performance. This paper hopes to inspire further SC electrode materials studies based on its novel morphology modulation strategy. Full article

Nitrate pollution in groundwater poses severe threats to ecosystems and human health, making the electrochemical nitrate reduction reaction (NO₃RR) a promising remediation technology. Conductive metal–organic frameworks (cMOFs) with π-d conjugation, dispersed active sites, and tunable structures are ideal candidates for electrocatalysis. Herein, we synthesized a series of cMOFs (M₃(HHTP)₂, M = Fe, Zn, Cu, Co, Ni) via conjugated coordination between hexahydroxytriphenylene (HHTP) ligands and metal ions and systematically investigated their NO₃RR performance. Electrochemical tests revealed that Fe₃(HHTP)₂ exhibits superior catalytic performance for nitrate reduction, achieving a high NH₃ selectivity of 99.5% and a yield rate of 676.4 mg·g_cat⁻¹·h⁻¹ at −1.0 V vs. RHE (reversible hydrogen electrode), along with excellent cyclic and structural stability. In situ attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy identified key intermediates (*NO₂, *NH₂OH) and proposed the reaction pathway: NO₃⁻ → *NO₃ → *NO₂ → *NO → *NOH → *NH₂OH → *NH₂ → *NH₃. DFT calculations revealed that Fe center exhibited a lower energy barrier for NO₃RR compared to other metal ions (Zn, Cu, Co, Ni). This study demonstrates the significant potential of Fe₃(HHTP)₂ for efficient NO₃RR and provides new insights into the structure-function relationship of cMOF-based electrocatalysts. Full article

Microbial fuel cells (MFCs) have attracted increasing attention due to their potential applications in renewable energy generation, waste utilization, and biomass upgrading, offering a promising alternative to traditional fossil fuels. By directly converting carbon-rich wastes into electricity, MFCs provide a unique approach to simultaneously address energy demand and waste management challenges. This review systematically examines the effects of various carbon-rich substrates on MFC performance, including lignocellulosic biomasses, molasses, lipid waste, crude glycerol, and C1 compounds. These substrates, characterized by wide availability, low cost, and high carbon content, have demonstrated considerable potential for efficient bioelectricity generation and resource recovery. Particular emphasis is placed on the roles of microbial community regulation and genetic engineering strategies in enhancing substrate utilization efficiency and power output. Additionally, the application of carbon-rich wastes in electrode fabrication is discussed, highlighting their contributions to improved electrical conductivity, sustainability, and overall system performance. The integration of carbon-rich substrates into MFCs offers promising prospects for alleviating energy shortages, improving wastewater treatment efficiency, and reducing environmental pollution, thereby supporting the development of a circular bioeconomy. Despite existing challenges related to scalability, operational stability, and system cost, MFCs exhibit strong potential for large-scale implementation across diverse industrial sectors. Full article

Low-voltage primary batteries broadly power small electronics used in health, biomedical, and wearable applications. These devices are generally more sensitive to volumetric capacity than gravimetric capacity. The current state-of-the-art button battery is Zn-Ag₂O, where contributors that limit volumetric capacity include the incorporation of inactive materials in the electrode microstructure such as gelling agents, binders, and conductive additives. Herein, cathode materials of CuO and FeS₂ will be described for small form factor coin/button cells. When paired with Li metal anodes, the operating voltage is similar to Zn-Ag₂O. The key innovation is that they will be processed into all-active-material (AAM) electrode architectures, where the electrodes will comprise only electroactive materials and pores that are filled with electrolyte during cell fabrication. The AAM architecture significantly enhanced electroactive material volume utilization, and thus volumetric capacity. FeS₂ and CuO were processed into AAM electrodes under various processing conditions, and Li-FeS₂ and Li-CuO primary batteries were fabricated and evaluated. At the cell level, volumetric capacity of 1300 mAh cm⁻³ was achieved, and in a button cell form factor 395/927, nearly 100 mAh was delivered, which compares favorably with commercially available options, which typically range from 27 to 55 mAh. Full article

Supercapacitors have attracted significant interest as increased energy storage devices due to their high power density, rapid charge/discharge performance, and long cyclability. In this study, NiO, Co₃O₄, NCO, and NCO/rGO composite electrodes were prepared and evaluated for high-performance supercapacitor applications. The uniform distribution of elements and the effective incorporation of rGO into the composite were confirmed by structural and morphological characterizations. Among the evaluated materials, the NCO/rGO electrode exhibited high electrochemical performance, delivering a specific capacitance of 998 F g⁻¹ in a three-electrode configuration, attributed to the enhanced redox activity of NiCo₂O₄ coupled with the enhanced electrical conductivity of rGO. Additionally, an asymmetric supercapacitor device with activated carbon as the negative electrode and NCO/rGO as the positive electrode showed a power density of 750 W kg⁻¹, an energy density of 29.2 Wh kg⁻¹, and a specific capacitance of 93.7 F g⁻¹. After 5000 charge/discharge cycles, the device maintained 85% of its initial capacitance and a coulombic efficiency of 99%, demonstrating exceptional cyclability. These results highlight the strong potential of the NiCo₂O₄/rGO composite as an advanced electrode material for next-generation energy storage systems. Full article

Current electrical self-sensing methods for composite structural health monitoring face significant limitations. Firstly, they often require complicated electrode layouts. Secondly, accurately determining both the location and amplitude of external loads remains a significant challenge. In this study, a deep learning-based self-sensing method is developed to identify the location and amplitude of external mechanical loads in resin-based conductive composites with a simple electrode layout. First, conductive filler-filled resin composites are prepared, and three-dimensional conductive networks are constructed within them. Subsequently, four electrodes are installed at the edges of the composite plate, and boundary electrical resistance responses are collected when applying mechanical loads at various positions on the composite plate. Finally, a residual learning-based CNN model is proposed for the accurate localization and amplitude identification of the applied loads. Research results demonstrate that the trained CNN model can accurately and effectively determine both the load amplitude and position. The obtained localization error and amplitude error are 0.91 mm and 0.13 N, respectively, surpassing the reported error values in previous studies. The research presented here opens a new avenue for achieving highly accurate and efficient prediction of load location and amplitude, which can be widely applied in composite structural health monitoring. Full article

Optimizing efficient electrode materials that combine high energy density, rapid charge transport, and excellent cycling stability remains a challenge for advanced supercapacitors. Here, we report the synthesis of an innovative copper(I)-based metal–organic framework (MOF), Cu₃(NDI)₃, prepared via a simple solvothermal method using N,N’-bis(3,5-dimethylpyrazol-4-yl)-naphthalene diimide (H₂NDI-H) as a linker. Structural analyses (XRD, FTIR, SEM, EDX, and BET) confirmed the formation of a highly crystalline, porous MOF. Integration of this MOF into laser-induced graphene (LIG) matrices yielded hybrid electrodes with enhanced structural characteristics and electrochemical activity, compared to its only-LIG counterpart. Electrochemical studies (CV, CD, EIS) revealed that the LIG–MOF electrode exhibited the highest performance, delivering a specific capacitance of 4.6 mF cm⁻² at 0.05 mA cm⁻², and an areal energy density of 60.03 μWh cm⁻² at a power density of 1292.17 μW cm⁻², outperforming both LIG and MOF–LIG configurations. This enhancement arises from the synergetic interaction between the conductive LIG network and the redox-active Cu₃(NDI)₃ framework, highlighting the potential of LIG–MOF hybrids as next-generation materials for high-performance supercapacitors. Full article

The Mixed-Conduction Model for oxide films is used to quantitatively interpret in situ electrochemical and ex situ surface analytical results on the corrosion of AISI 316L (an internal reactor material) and Alloy 690 (a steam generator tube material) in small modular reactor primary coolant with the addition of soluble Zn. The model parameters of alloy oxidation and corrosion release are estimated with the time of exposure up to 168 h and anodic polarization potential (up to −0.25 V vs. standard hydrogen electrode) using fitting of the transfer function to experimental impedance spectra. Model parameters of individual alloy constituents are estimated by fitting of the model equations to the atomic fraction profiles of respective elements in the formed oxide obtained by Glow-Discharge Optical Emission Spectroscopy (GDOES). Conclusions on the effect of Zn addition on film growth and cation release processes in boron-free SMR coolant are drawn and future research directions are outlined. Full article

Graphene oxide (GO) and reduced graphene oxide (rGO) have solidified their role as cornerstone nanomaterials in the pursuit of sustainable technology. This review synthesizes recent advances in harnessing the unique properties of GO and rGO such as their tunable surface chemistry and exceptional electrical conductivity for applications spanning environmental remediation and energy storage. In the environmental domain, they function as superior adsorbents and catalysts for the removal of hazardous pollutants. Concurrently, in the energy sector, their integration into supercapacitors and battery electrodes significantly enhances energy and power density. The adaptability of these materials also facilitates the creation of highly sensitive sensors and biosensors. However, the transition from laboratory research to widespread industrial application is hindered by challenges in scalable production, environmental health and safety concerns, and long-term stability. This review enhances the understanding of GO and rGO’s diverse applications and paves the way for future sustainable technologies in energy and environmental sectors. Full article

Background and Objectives: Epilepsy is a chronic neurological disorder characterized by recurrent seizures caused by abnormal brain activity. Reliable near-real-time seizure detection is essential for preventing injuries, enabling early interventions, and improving the quality of life for patients with drug-resistant epilepsy. This study presents a near-real-time epileptic seizure detection framework designed for low-latency operation, focusing on improving both clinical reliability and patient comfort through electrode reduction. Method: The framework integrates bidirectional long short-term memory (BiLSTM) networks with wavelet-based feature extraction using Electroencephalogram (EEG) recordings from the EPILEPSIAE dataset. EEG signals from 161 patients comprising 1032 seizures were analyzed. Wavelet features were combined with raw EEG data to enhance temporal and spectral representation. Furthermore, electrode reduction experiments were conducted to determine the minimum number of strategically positioned electrodes required to maintain performance. Results: The optimized BiLSTM model achieved 86.9% accuracy, 86.1% recall, and an average detection delay of 1.05 s, with a total processing time of 0.065 s per 0.5 s EEG window. Results demonstrated that reliable detection is achievable with as few as six electrodes, maintaining comparable performance to the full configuration. Conclusions: These findings demonstrate that the proposed BiLSTM-wavelet approach provides a clinically viable, computationally efficient, and wearable-friendly solution for near-real-time epileptic seizure detection using reduced EEG channels. Full article

Waterborne polyurethane (WPU) and waterborne poly(urethane-urea) (WPUU) dispersions allow safer and more sustainable manufacturing of rechargeable batteries via water-based processing, while offering tunable adhesion and segmented-domain mechanics. Beyond conventional roles as binders and coatings, WPU/WPUU chemistries also support separator/interlayer and polymer-electrolyte designs for lithium-ion and lithium metal systems, where interfacial integrity, stress accommodation, and ion transport must be balanced. Here, we review WPU/WPUU fundamentals (building blocks, dispersion stabilization, morphology, and film formation) and review prior studies through a battery-centric structure–processing–property lens. We point out key performance-limiting trade-offs—adhesion versus electrolyte uptake and ionic conductivity versus storage modulus—and relate them to practical formulation variables, including soft-/hard-segment selection, ionic center/counterion design, molecular weight/topology control, and crosslinking strategies. Applications are reviewed for (i) electrode binders (graphite/Si; cathodes such as LFP and NMC), (ii) separator coatings and functional interlayers, and (iii) gel/solid polymer electrolytes and hybrid composites, with a focus on practical design guidelines for navigating these trade-offs. Future advancements in WPU/WPUU chemistries will depend on developing stable, low-impedance interlayers, enhancing electrochemical behavior, and establishing application-specific design guidelines to optimize performance in lithium metal batteries (LMB). Full article

Lithium thermal batteries are primary reserve batteries utilizing solid molten salt electrolytes. They are regarded as ideal power sources for high-reliability applications due to their high power density, rapid activation, long shelf life, wide operating temperature range, and excellent environmental adaptability. However, existing electrode systems are limited by insufficient conductivity and the use of high-impedance MgO binders. This results in sluggish electrode reaction kinetics and incomplete material conversion during high-temperature discharge, causing actual discharge capacities to fall far below theoretical values. To address this, FeS₂-CoS₂ multi-component composite cathode materials were synthesized via a high-temperature solid-phase method. Furthermore, two distinct MgO binders were systematically investigated: flake-like MgO (MgO-F) with a sheet-stacking structure and spherical MgO (MgO-S) with a low-tortuosity granular structure. Results indicate that while MgO-F offers superior electrolyte retention via physical confinement, its high tortuosity limits ionic conduction. In contrast, MgO-S facilitates the construction of a wettability-enhanced continuous ionic network, which effectively reduces interfacial impedance and enhances system conductivity. This regulation promoted Li⁺ migration and accelerated interfacial reaction kinetics. This study provides a feasible pathway for improving the electrochemical performance of lithium thermal batteries through morphology-oriented MgO binder regulation. Full article

In recent years, electrochemical pressure (ECP) sensors with self-powered and both dynamic and static pressure detection capabilities have received widespread attention. To improve pressure sensing performances while reducing the thickness of conventional sandwich structure ECP sensors, we propose an ECP sensor with a simple electrode coplanar structure. Specifically, it consists of Cu/Zn foil electrodes and LiCl/polyvinyl alcohol (PVA) modified filter paper. Among them, the Cu/Zn coplanar electrodes are used for redox reactions, the LiCl provides conductive ions, and the PVA is used to provide a humid environment to promote the ionization and conduction of LiCl. The rough surface microstructure of the filter paper is used to enhance the pressure sensing performances of the sensor. The results show that the ECP sensor with an electrode coplanar structure can spontaneously output current in the pressure range of 0.4–100 kPa, with sensitivities of 0.273 kPa⁻¹ (0.6–20 kPa) and 0.036 kPa⁻¹ (20–100 kPa). Specifically, compared to ECP sensors with a sandwich structure, it has a wider response range and higher sensitivity. Through the current response, morphological characterizations, and redox reactions, the pressure sensing mechanism is elucidated. Furthermore, the proposed ECP sensor can be used for respiratory state recognition combined with machine learning. This research provides a new approach for developing a high-performance ECP sensor with a simple electrode coplanar structure. Full article