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Electrochemical CO2 reduction reaction (CO2RR) coupled with renewable electricity holds promises for efficient mitigation of carbon emission impacts on the environment and turning CO2 into valuable chemicals. One important task in CO2RR development is the design and fabrication of efficient electrodes for stable operation in the long term. Gas‐diffusion electrodes (GDEs) have been employed to continuously feed CO2 to the electrolyzers. Despite significant advances in GDE design and tailoring GDE properties, the present GDEs often suffer from the critical issue of flooding due to the electrowetting of carbon‐based substrates, which hinders the transition to industrial application. To address flooding, GDEs with intrinsically hydrophobic polymeric substrates have been recently fabricated and have shown promising performances. Herein, the advances and challenges associated with carbon‐free GDEs are reviewed for CO2RR. This review first briefly outlines GDE and electrolyzers basics. Through critical discussion around the shortcomings of conventional carbon‐based GDEs, the most recent efforts to resolve flooding are summarized. Subsequently, the advances, advantages, and challenges of carbon‐free GDEs are elaborated. Finally, priorities for future studies are suggested, with the aim to support the advancement and scale‐up of carbon‐free GDEs and extend them to other electrochemical systems where gas and the electrolyte are in contact. [ABSTRACT FROM AUTHOR]

An ever-increasing market demand has stimulated the soaring enthusiasm of researchers to develop wide-temperature super-capacitors (SCs). The active electrode is one of the most important parts of SC, which is directly related to the energy density, power transmission and long-term cyclability of the device in the wide-temperature environment. Compared with the SC electrodes aimed for room-temperature application, the SC electrodes for operating at wide-temperature scene often face greater challenges. In this review, the main challenges of SC electrodes under various temperature conditions, including low, high and cross-fade temperatures, are summarized. The relevant performance decay and failure mechanisms of wide-temperature SC electrodes are analyzed. In addition, this review deals with the recent studies and developments in robust wide-temperature SC electrodes with respect to the rational design of electrode structures and the exploitation of advanced active materials. Finally, the future directions for exploring reliable wide-temperature SCs are also proposed. [ABSTRACT FROM AUTHOR]

Aqueous potassium‐ion batteries (AKIBs) with mild aqueous electrolytes can significantly mitigate the safety and environmental issues raised from traditional nonaqueous batteries, positioning them as promising candidates for grid‐scale applications. Nonetheless, the progression of AKIBs is currently impeded by the insufficient energy density, largely attributed to the limited voltage window of aqueous electrolytes. This review aims to introduce foundational knowledge about aqueous batteries, illustrates recent advancements in AKIBs, and offers valuable perspectives on designing electrode materials and optimizing electrolytes. To provide a systematic overview, the focus is on the following seven key sections: i) development history, ii) electrode materials, iii) electrolyte design, iv) current collectors, v) aqueous interphase chemistry, vi) full cell configurations, and vii) future prospects. Finally, constructive insights and suggestions are provided for the development of AKIBs with higher energy density. [ABSTRACT FROM AUTHOR]

This study presents a novel approach to developing high-performance lithium-ion battery electrodes by loading titania-carbon hybrid spherogels with sulfur. The resulting hybrid materials combine high charge storage capacity, electrical conductivity, and core-shell morphology, enabling the development of next-generation battery electrodes. We obtained homogeneous carbon spheres caging crystalline titania particles and sulfur using a template-assisted sol-gel route and carefully treated the titania-loaded carbon spherogels with hydrogen sulfide. The carbon shells maintain their microporous hollow sphere morphology, allowing for efficient sulfur deposition while protecting the titania crystals. By adjusting the sulfur impregnation of the carbon sphere and varying the titania loading, we achieved excellent lithium storage properties by successfully cycling encapsulated sulfur in the sphere while benefiting from the lithiation of titania particles. Without adding a conductive component, the optimized material provided after 150 cycles at a specific current of 250 mA g-1 a specific capacity of 825 mAh g-1 with a Coulombic efficiency of 98%.

Traditional electrical discharge machining (EDM) electrodes have several limitations such as long machining time, low material removal rate MRR, hazard emissions and high energy consumption. To overcome these limitations, new electrodes (plane and frame U-shaped) were manufactured considering the electrode manufacturing classifications, such as electrode flushing mechanism, electrode cross-sectional area and electrode bottom machining area. Experiments were performed on a die-sinking EDM machine using copper electrodes and aluminum alloy workpieces. The results were compared with those obtained using the conventional electrode. The newly manufactured electrodes significantly improved the EDM process performance, reducing the machining time by more than 50%, which implies a higher MRR. The reduced machining time also led to lower costs, emissions and energy consumption for efficient EDM processes. Additionally, surface roughness measurements were performed to compare the surface quality of the machined areas using different pulse-code generator systems and electrodes. The results showed an improvement in the machined surface quality when using the new electrodes in comparison with the conventional electrode when using a roughing pulse code generator system. [ABSTRACT FROM AUTHOR]

Current liquid crystal (LC) lenses cannot achieve lossless arbitrary movement of the optical axis without mechanical movement. This article designs a novel bottom electrode through simulation and optimization, which forms a special LC lens with an Archimedean spiral electrode, realizing a 3D LC wedge and an arbitrarily movable LC lens. When only the bottom electrode is controlled, it achieves a maximum beam steering angle of 0.164°, which is nearly an order of magnitude larger than the current design. When the top and bottom electrodes are controlled jointly, a 0.164° movement of the lens optical axis is achieved. With focal length varies, the movement of the optical axis ranges from zero to infinity, and the lens surface remains unchanged during movement. The focus can move in a 3D conical area. When the thickness of the LC layer is 30 μm, the fastest response time reaches only 0.635 s, much faster than now. [ABSTRACT FROM AUTHOR]

Anion-exchange-membrane water electrolyzers (AEMWEs) provide a promising pathway to utilize low-carbon renewable electricity to produce clean hydrogen at high efficiency and purity, while maintaining low system costs compared to incumbent technologies. Though significant progress has been made in developing membranes and catalysts, AEMWEs still require better performance and durability to realize widespread deployment. Here, we overcome these challenges by decoupling anode and cathode polarization behavior via integration of a reference electrode in the membrane-electrode assembly. This measurement identified that the mass-transport losses dominate the cathode overpotential if feeding with electrolytes, while kinetic losses dominate the anode overpotential. These losses are mitigated by varying electrode properties and operating strategies, where a more hydrophobic, optimal loaded cathode, a high porosity anode, and operating with the cathode dry exhibited the best performance. These findings eventually enabled achieving a high-performing and durable complete PGM-free AEMWE operating at 1.5 A cm−2 for over 500 h with negligible degradation, demonstrating significant progress for AEMWEs.

Developing a hydrogen evolution reaction (HER) electrocatalyst that can steadily drive a large current density is of great significance for industrial electrochemical water‐splitting technology. Herein, the compositionally complex noble‐metal‐lean system Co–Cu–Mo–Pd–Re is investigated for alkaline HER by a scanning droplet cell‐assisted high‐throughput screening of co‐sputtered thin‐film material libraries. The identified hit compositions are used to prepare a catalyst‐coated Ni foam‐based layer that is hot‐pressed with a specifically designed PEEK‐covered carbon‐based gas diffusion layer to obtain a novel‐design gas diffusion electrode (GDE). H2 bubbles that collect on the electrode surface are effectively reduced by controlling the hydrophobicity of the catalyst layer of the GDE, hence enabling a high current (−1 A cm−2) operation for HER in alkaline water electrolysis. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) are regarded as next‐generation secondary batteries and complement to lithium‐ion batteries (LIBs) for large‐scale electrochemical energy storage applications due to the abundant availability, even distribution, and cost‐effectiveness of raw sodium resources. The phosphate‐based polyanions stand out of various cathode material owing to their high operation voltage, stable structure, superior safety, and excellent sodium‐storage properties. The undesirable electric conductivities and specific capacities limit their large‐scale industrialization. Herein, a recent research development of phosphate‐based polyanion cathodes including orthophosphate, oxyphosphate, pyrophosphate, and mixed phosphates is thoroughly reviewed. Subsequently, the effect of modification strategies including element doping, surface coating, morphology control, and electrode design toward high‐performance cathode materials for SIBs are systematically explored. Finally, the future research directions of phosphate‐based polyanion cathodes based on electrochemical performance including reversible capacity, voltage, energy density, rate capacity, cycling stability, and commercial applications are comprehensively concluded. It is believed that current review will present instructive perspectives into developing practicable phosphate‐based polyanion cathode materials for SIBs. [ABSTRACT FROM AUTHOR]

The accelerated oxidative degradation observed in all‐solid‐state batteries (ASSBs), particularly focusing on the argyrodite solid electrolyte in conjunction with Ni‐rich positive electrode surfaces is demonstrated. The formation of oxidative intermediates of the solid electrolyte oxidation process increases the amount of oxidation on the NCM surface with conductive carbon. The introduction of high‐weight‐composition conductive carbon additives results in a reduction of solid electrolytes within the positive electrode and the amount of solid electrolytes retained after formation. Consequently, cells with high concentrations of carbon additives demonstrate a decrease in both the cycle and power performances of ASSBs. The energy density of ASSBs is significantly limited by the fundamental failure mechanism induced by conductive carbon, particularly pronounced in cells with high active material contents. Consequently, this study provides pivotal insights for the design of high‐energy‐density ASSBs with NCM electrodes and high active material contents. To mitigate failure induced by high‐volumetric‐occupied carbon additives, carbon fiber‐type additives are further utilized to interconnect the NCMs by decreasing the occupation of the solid electrolyte domain by carbon. Morphological alteration of the carbon additive significantly improves the electrochemical performance of ASSBs by preventing the deterioration of the electrode structure even after prolonged cycling and suppressing electrolyte degradation. [ABSTRACT FROM AUTHOR]

Cochlear implants are crucial for addressing severe-to-profound hearing loss, with the success of the procedure requiring careful electrode placement. This scoping review synthesizes the findings from 125 studies examining the factors influencing insertion forces (IFs) and intracochlear pressure (IP), which are crucial for optimizing implantation techniques and enhancing patient outcomes. The review highlights the impact of variables, including insertion depth, speed, and the use of robotic assistance on IFs and IP. Results indicate that higher insertion speeds generally increase IFs and IP in artificial models, a pattern not consistently observed in cadaveric studies due to variations in methodology and sample size. The study also explores the observed minimal impact of robotic assistance on reducing IFs compared to manual methods. Importantly, this review underscores the need for a standardized approach in cochlear implant research to address inconsistencies and improve clinical practices aimed at preserving hearing during implantation. [ABSTRACT FROM AUTHOR]

Electrical discharge machining (EDM), especially the die-sinking variant, is a well-known slow machining process among non-conventional manufacturing processes. Different approaches are being researched to improve EDM performance characteristics especially increasing its material removal rate (MRR) and reducing the tool wear rate (TWR). This study aims to improve the EDM process performance through modifications in tool design and employing different tool materials. The performance of conventional EDM tool is compared with different tool designs while machining D2 steel. Moreover, tool designs are employed on different tool materials including copper (Cu), copper-tungsten alloy (CuW), and graphite (Gr) to investigate the combined effect of tool designs and materials on important performance indicators of EDM die-sinking. The machining time (MT), material removal rate (MRR), lateral tool wear (TWR_L), and diametric tool wear (TWR_D) are selected as the response measures. The modified tool designs reduce the machining time by 45%. Likewise, Cu and CuW remarkably improve the material removal rate by 80%. Similarly, the lateral and diametric tool wear of modified designs are less than the wear corresponding to conventional design. Microscopic analysis revealed two wear zones which are named as aggressive sparking zone and mild sparking zone. All materials (Cu, CuW, and Gr) with the modified tool designs show significantly less sparking zone compared with the conventional design. Moreover, the most appropriate combination of tool design and material is proposed to achieve better EDM performance.

For decades, radiofrequency (RF)-induced tissue fusion has garnered great attention due to its potential to replace sutures and staples for anastomosis of tissue reconstruction. However, the complexities of achieving high bonding strength and reducing excessive thermal damage present substantial limitations of existing fusion devices. This study proposed a discrete linkage-type electrode to carry out ex vivo RF-induced intestinal anastomosis experiments. The anastomotic strength was examined by burst pressure and shear strength test. The degree of thermal damage was monitored through an infrared thermal imager. And the anastomotic stoma fused by the electrode was further investigated through histopathological and ultrastructural observation. The burst pressure and shear strength of anastomotic tissue can reach 62.2 ± 3.08 mmHg and 8.73 ± 1.11N, respectively, when the pressure, power and duration are 995 kPa, 160 W and 13 s, and the thermal damage can be controlled within limits. Histopathological and ultrastructural observation indicate that an intact and fully fused stomas with collagenic crosslink can be formed. The discrete linkage-type electrode presents favorable efficiency and security in RF-induced tissue fusion, and these results are informative to the design of electrosurgical medical devices with controllable pressure and energy delivery. [ABSTRACT FROM AUTHOR]

Alkaline fuel cells (AFC) have proven to provide high power densities and can attain considerable lifetimes, thus making them a worthy competitor to proton exchange membrane fuel cells (PEMFC). The electrolytes are based on aqueous bases and are relatively inexpensive. The non-corrosive nature of their electrolyte facilitates diverse usage of various catalyst materials apart from platinum, thus enabling the mass production of low-cost fuel cells. This review provides a summarized overview of AFCs. It sheds light on its fundamental operational principles, the most recent research trends related to catalyst developments, its system components and stack designs, and also provides a brief performance analysis section that highlights how the performance of an AFC is impacted upon varying different system parameters (e.g. electrolyte concentration, electrolyte thickness, and operating temperatures). This parametric study has shown that increasing the electrolyte concentration from 1–61 mol/L results in an increase in the AFC’s peak power density from 72.9 to 169 W/m2. Similarly, increasing the cell’s operating temperatures from 243–283 K yields increased peak power densities from 112 to 140 W/m2. This is mainly attributed to the enhancement of the electrolyte’s specific conductivity and the cell’s overall electrochemical kinetics. Increasing the electrolyte thickness, however, decreases the performance of an AFC, where peak power densities fall from 123 to 66 W/m2 when the thickness increases from 1 to 5 μm. This is a consequence of the increased internal resistances encountered by the hydroxyl ions as they migrate through the electrolyte.

Current liquid crystal (LC) lenses cannot achieve lossless arbitrary movement of the optical axis without mechanical movement. This article designs a novel bottom electrode through simulation and optimization, which forms a special LC lens with an Archimedean spiral electrode, realizing a 3D LC wedge and an arbitrarily movable LC lens. When only the bottom electrode is controlled, it achieves a maximum beam steering angle of 0.164°, which is nearly an order of magnitude larger than the current design. When the top and bottom electrodes are controlled jointly, a 0.164° movement of the lens optical axis is achieved. With focal length varies, the movement of the optical axis ranges from zero to infinity, and the lens surface remains unchanged during movement. The focus can move in a 3D conical area. When the thickness of the LC layer is 30 μm, the fastest response time reaches only 0.635 s, much faster than now.

The urgency of achieving green chemical production through Cu-based CO2 electroreduction necessitates a rapid transition towards technical maturity and commercialization in the pursuit of addressing the global imperative of decarbonization. Surprisingly, limited emphasis has been placed on exploration of readily scalable cell and electrode designs, which are pivotal in ushering in the era of stable and selective CO2 electrolyzers, showcasing the innovative potential within this area. Herein, we report a breakthrough in achieving month-long stability in the production of C2H4, representing an unprecedented milestone in low-temperature CO2 to C2+ electrolysis. Initial investigations involved the evaluation of five distinct cell architectures for Cu-based CO2 electrolyzers, guided by considerations of cell potentials, scalability with current technology, and CO2 crossover. An innovative multilayer Gas Diffusion Electrode (GDE), featuring an anion exchange ionomer and metal oxide layer, is introduced for CEM-based zero-gap cells, enabling C2H4 formation despite acidic surroundings. However, selectivity towards C2H4 proved suboptimal for extended stability testing. Conversely, the tailored multilayer GDE for one-gap cell architecture achieves a commendable 54 % faradaic efficiency (FE) towards C2+ products at 300 mA/cm2. Remarkably, chronopotentiometric tests demonstrate 720 h of stability (FEC2H4 > 20 %) at 100 mA/cm2. At higher current densities (300 mA/cm2), stability is reduced to 75 h, with detailed analyses revealing distinct degradation mechanisms. At 100 mA/cm2, salt formation predominates, while at 300 mA/cm2, catalyst layer restructuring degrades catalytic activity towards C2H4. Our research underscores the potential for stable, high C2+ selectivity through innovative electrode design and scalable cell architectures, advancing sustainable CO2 utilization.

All-solid-state lithium batteries (ASSLBs) hold immense promise as next-generation energy storage systems. A crucial aspect of ASSLB development lies in achieving high energy density, which demands the high mass loadings of cathode active material. However, thick cathode with high mass loading may introduce various challenges, such as interfacial resistance between electrolytes and electrodes, suboptimal ion conduction, and limited battery lifespan. To address these challenges, composite cathode has been engineered by integrating solid-state electrolytes into conventional cathodes to enhance ion transport. Solid polymer electrolytes (SPEs), in particular, stand out for their ability to mitigate interfacial issues during cycling due to their elasticity and flexibility compared to their inorganic counterparts. This review offers a comprehensive overview of efforts to incorporate SPEs into catholytes for ASSLBs. It begins with a discussion on catholyte composition, emphasizing the properties of their constituent components. Subsequently, it provides a concise overview of electrochemical transport and measurement techniques. The review then delves into efficient and cost-effective fabrication processes, highlighting their significance. Finally, it underscores the crucial role of SPEs in advancing the development of catholytes for the future. [ABSTRACT FROM AUTHOR]

Microbial fuel cells (MFCs) offer a dual solution of generating electrical energy from organic pollutants-laden wastewater while treating it. This study focuses on enhancing MFC performance through innovative electrode design. Three-dimensional (3D) anodes, created from corncobs and mango seeds via controlled graphitization, achieved remarkable power densities. The newly developed electrode configurations were evaluated within sewage wastewater-driven MFCs without the introduction of external microorganisms or prior treatment of the wastewater. At 1,000°C and 1,100°C graphitization temperatures, corncob and mango seed anodes produced 1,963 and 2,171 mW/m2, respectively, nearly 20 times higher than conventional carbon cloth and paper anodes. An advanced cathode composed of an activated carbon-carbon nanotube composite was introduced, rivaling expensive platinum-based cathodes. By optimizing the thermal treatment temperature and carbon nanotube content of the proposed cathode, comparable or superior performance to standard Pt/C commercial cathodes was achieved. Specifically, MFCs assembled with corncob anode with the proposed and standard Pt/C cathodes reached power densities of 1,963.1 and 2,178.6 mW/ m2, respectively. Similarly, when utilizing graphitized mango seeds at 1,100°C, power densities of 2,171 and 2,151 mW/m2 were achieved for the new and standard cathodes, respectively. Furthermore, in continuous operation with a flow rate of 2 L/h, impressive chemical oxygen demand (COD) removal rates of 77% and 85% were achieved with corncob and mango seed anodes, respectively. This work highlights the significance of electrode design for enhancing MFC efficiency in electricity generation and wastewater treatment. [ABSTRACT FROM AUTHOR]

Context: This work theoretically demonstrates a catalyst of copper monatomic wire supported on graphene nanoribbons (Cu-GNR) with a high efficiency for nitric oxide electroreduction reaction (NORR). This not only decreases the usage rate of noble metals but also possesses superior limiting potential comparable to pure Cu (− 0.69 and − 0.61 V, vs. reversible hydrogen electrode (RHE)). The key is that Cu-GNR will have more efficient catalytic activity for NORR when fully covered by NO, since these weaken the adsorption ability of the reduction steps at the beginning. In sum, our findings may offer a platform for clarifying the effects of the concentration of reactants on catalytic process. Methods: Spin-polarized DFT with ultrasoft pseudopotentials as implemented in the CASTEP code was used in this work. The exchange correlation effects were described by generalized gradient approximation (GGA) with Perdew-Burke-Ernzerhof (PBE) functional. The dispersion correction within Grimme scheme (DFT-D2) was employed to accurately describe the van der Waals (vdW) interactions. The Hirshfeld population analysis was adopted to evaluate the charge transfer. [ABSTRACT FROM AUTHOR]

BACKGROUND: The experimental process for optimizing microbial fuel cell (MFC) design under different electrode geometries is restricted. An MFC can be defined as a bio‐electrochemical system (BES) that facilitates the direct conversion of the chemical energy stored in organic matter into electrical energy by harnessing the metabolic activity of microorganisms. Computational fluid dynamics (CFD) tools allow the simulation and evaluation of electro‐analysis phenomena such as cyclic voltammetry and chemical reactions, which can help the optimization of the BESs. In this study, MFC is designed to provide the maximum peak current and efficiency for the applied voltage on various working (or anode) electrode geometries (i.e. hexagonal, square, pentagonal, circular, triangular, rectangular, and rhombus). RESULTS: The CFD simulation results demonstrate that a configuration with a larger perimeter value and surface area (i.e. hexagonal design) of the working electrode shows a higher peak current (2422.75 mA) than other configurations. The experimental findings supported the simulation result and reveal that a hexagonal electrode containing a MFC setup produces a maximum power density of 22.41 ± 0.32 mW m−3 and a current density of 41.58 ± 0.35 mA m−2. The MFC operation demonstrated adequate bioelectricity generation of 540 ± 03 mV on Day 4 of operation at 1000 Ω. Additionally, maximum reduction in chemical oxygen demand (76.13 ± 0.5%) and coulombic efficiency (76.03 ± 0.4%) was achieved for synthetic wastewater using a hexagonal MFC. CONCLUSION: Based on these fundamental discoveries, the CFD simulation and its experimental validation considerably drag focus toward the possibility of employing COMSOL Multiphysics software for system improvement of different MFC system applications. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Measuring the electrical conductivity (EC) of plant substrates is an effective way to assess their nutrient content. This study aims to compare the performance of EC sensors with varying electrode sizes and spacings when embedded in a plant substrate. The range of electrode sizes and spacings varied from 0.1 mm to 10 mm. The EC electrodes were embedded in a porous plant substrate and subjected to wet–dry cycles. The results showed that the electrodes with larger electrode dimensions and spacing produce valid EC values. [ABSTRACT FROM AUTHOR]

The electrochemical CO2 reduction reaction (CO2RR), driven by renewable energy, provides a potential carbon‐neutral avenue to convert CO2 into valuable fuels and feedstocks. Conversion of CO2 into formic acid/formate is considered one of the economical and feasible methods, owing to their high energy densities, and ease of distribution and storage. The separation of formic acid/formate from the reaction mixtures accounts for the majority of the overall CO2RR process cost, while the increment of product concentration can lead to the reduction of separation cost, remarkably. In this paper, we give an overview of recent strategies for highly concentrated formic acid/formate products in CO2RR. CO2RR is a complex process with several different products, as it has different intermediates and reaction pathways. Therefore, this review focuses on recent study strategies that can enhance targeted formic acid/formate yield, such as the all‐solid‐state reactor design to deliver a high concentration of products during the reduction of CO2 in the electrolyzer. Firstly, some novel electrolyzers are introduced as an engineering strategy to improve the concentration of the formic acid/formate and reduce the cost of downstream separations. Also, the design of planar and gas diffusion electrodes (GDEs) with the potential to deliver high‐concentration formic acid/formate in CO2RR is summarized. Finally, the existing technological challenges are highlighted, and further research recommendations to achieve high‐concentration products in CO2RR. This review can provide some inspiration for future research to further improve the product concentration and economic benefits of CO2RR. [ABSTRACT FROM AUTHOR]

Microsized‐silicon (µ‐Si, >1 µm) is one of the ideal anodes for lithium‐ion batteries due to its low‐cost, high tap density, and high specific capacity. However, during repeated lithiation/delithiation processes, µ‐Si undergoes huge volume changes. This leads to continued capacity loss during cycling due to severe particle pulverization, separation from the conductive network and uncontrolled growth of an unstable solid‐electrolyte interphase (SEI). Herein, an electrode construction strategy is proposed by carbonization of the slurry‐casting µ‐Si electrode. The organic binder serves as both carbon resource and physical framework, which is carbonized to form a carbon binder that is chemically bonded with the µ‐Si particles and within the electrode. The electrode with carbon binder ensures stable electric channel and promotes formation of a stable and passivating SEI at the interface with a high µ‐Si content up to 82 wt%. The carbon binder offers physical buffer that shield against localized strain and modifies the surface reactivity, which enables a high initial Coulombic efficiency (91.85%) and stable cycle performance at commercial‐level areal capacities (2 mAh cm−2). This work offers an easily scalable yet practical approach for the current battery industry without any electrolyte modification or complicated manufacturing methods. [ABSTRACT FROM AUTHOR]

Background: Non‐ablative radiofrequency (RF) has been widely used in clinical and at‐home cosmetics devices. RF electrode geometry can influence the heat distribution in the tissue. This study analyzes the influence of geometric parameters of the electrode on the heat distribution in the layered tissue. Materials & methods: The finite element simulation of the electrothermal coupling field was performed to obtain the three‐dimensional (3D) temperature distribution of the four‐layer tissue. The electrode geometric parameters including the inter‐electrode spacing (5‐12 mm), width (1‐3 mm), length (3‐10 mm), shapes (bar, dot and circle), and the coupling gel's electrical conductivity (0.2‐1.5 S/m) were simulated. The maximum temperature at 2 mm depth (T‐2 mm) and the temperature difference (Tdiff) between the maximum skin surface temperature and T‐2 mm were obtained to evaluate the effectiveness and safety. Results: The effect of geometric parameters on the effectiveness and safety was mixed. The maximum T‐2 mm occurred with the 5 mm inter‐electrode spacing, 3 mm width, 10 mm length, the circle‐shaped electrode, and the 1.5 S/m coupling gel's electrical conductivity. The ratio of inter‐electrode spacing to width at around four can achieve rapid temperature rise and skin surface temperature protection. The electrode shape influenced the area of temperature rise in the tissue's cross‐section. The coupling gel's electrical conductivity should be close to that of the skin to avoid energy accumulation on the skin surface. Conclusion: The electrode's geometric parameters affect the effectiveness and safety of the RF product. This study has provided the simulation procedure for the electrode design. [ABSTRACT FROM AUTHOR]

CO2 reduction, two‐electron O2 reduction, and N2 reduction are sustainable technologies to valorise common molecules. Their further development requires working electrode design to promote the multistep electrochemical processes from gas reactants to value‐added products at the device level. This review proposes critical features of a desirable electrode based on the fundamental electrochemical processes and the development of scalable devices. A detailed discussion is made to approach such a desirable electrode, addressing the recent progress on critical electrode components, assembly strategies, and reaction interface engineering. Further, we highlight the electrode design tailored to reaction properties (e.g. its thermodynamics and kinetics) for performance optimisation. Finally, the opportunities and remaining challenges are presented, providing a framework for rational electrode design to push these gas reduction reactions towards an improved technology readiness level (TRL). [ABSTRACT FROM AUTHOR]

CO2 reduction, two‐electron O2 reduction, and N2 reduction are sustainable technologies to valorise common molecules. Their further development requires working electrode design to promote the multistep electrochemical processes from gas reactants to value‐added products at the device level. This review proposes critical features of a desirable electrode based on the fundamental electrochemical processes and the development of scalable devices. A detailed discussion is made to approach such a desirable electrode, addressing the recent progress on critical electrode components, assembly strategies, and reaction interface engineering. Further, we highlight the electrode design tailored to reaction properties (e.g. its thermodynamics and kinetics) for performance optimisation. Finally, the opportunities and remaining challenges are presented, providing a framework for rational electrode design to push these gas reduction reactions towards an improved technology readiness level (TRL). [ABSTRACT FROM AUTHOR]

CO2 reduction, two‐electron O2 reduction, and N2 reduction are sustainable technologies to valorise common molecules. Their further development requires working electrode design to promote the multistep electrochemical processes from gas reactants to value‐added products at the device level. This review proposes critical features of a desirable electrode based on the fundamental electrochemical processes and the development of scalable devices. A detailed discussion is made to approach such a desirable electrode, addressing the recent progress on critical electrode components, assembly strategies, and reaction interface engineering. Further, we highlight the electrode design tailored to reaction properties (e.g. its thermodynamics and kinetics) for performance optimisation. Finally, the opportunities and remaining challenges are presented, providing a framework for rational electrode design to push these gas reduction reactions towards an improved technology readiness level (TRL). [ABSTRACT FROM AUTHOR]

CO2 reduction, two‐electron O2 reduction, and N2 reduction are sustainable technologies to valorise common molecules. Their further development requires working electrode design to promote the multistep electrochemical processes from gas reactants to value‐added products at the device level. This review proposes critical features of a desirable electrode based on the fundamental electrochemical processes and the development of scalable devices. A detailed discussion is made to approach such a desirable electrode, addressing the recent progress on critical electrode components, assembly strategies, and reaction interface engineering. Further, we highlight the electrode design tailored to reaction properties (e.g. its thermodynamics and kinetics) for performance optimisation. Finally, the opportunities and remaining challenges are presented, providing a framework for rational electrode design to push these gas reduction reactions towards an improved technology readiness level (TRL). [ABSTRACT FROM AUTHOR]

Capacitive deionization (CDI), an emerging method for water desalination and ion separation, has received much attention due to its advantages of high ion selectivity, high water recovery and low energy consumption. Compared with the traditional carbon electrodes, the emerging Faraday electrode offers a unique opportunity to make the desalination performance of CDI significantly improved through the Faraday reaction of ion capture. Transition metal-based electrodes have received much attention in the field of CDI electrode design due to their highly reversible Faraday response, relatively high conductivity, and excellent theoretical pseudocapacitance values. In this paper, we systematically summarize and sort out the material classification of transition metal-based electrodes in CDI applications, and summarize the modification engineering performed for their intrinsic defects, mainly including conductive material coupling, functional architecture engineering and defect engineering, etc., and summarize their performance in CDI applications; in addition, the specific applications of transition metal-based electrodes in CDI are particularly introduced in terms of ion selective separation, metal ion removal and nutrient element recovery. Finally, the paper also outlines the remaining challenges and research directions to provide guidance for future development and research of transition metal chemical substance electrodes. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) dominate the market of rechargeable power sources. To meet the increasing market demands, technology updates focus on advanced battery materials, especially cathodes, the most important component in LIBs. In this review, we provide an overview of the development of materials and processing technologies for cathodes from both academic and industrial perspectives. We briefly compared the fundamentals of cathode materials based on intercalation and conversion chemistries. We then discussed the processing of cathodes, with specific focuses on the mechanisms of a drying process and the role of the binders. Several key parameters for the development of thick electrodes were critically assessed, which may offer insights into the design of next-generation batteries.

High conductivity and mass transfer channels of electrode materials with high mass loadings are the fundamental requirements for achieving high‐rate performance and high‐volume energy density. In this study, we investigated the method of constructing high‐mass loading pellet electrodes and their applications in lithium metal batteries from three different perspectives: selecting active electrode materials, designing the mass transfer porous structure, and constructing a conductive network. The three‐dimensional conductive network with porous structures provides the electrolyte's mass transfer channels and convenient charge transfer paths. The resulting pellet electrode demonstrates Young's modulus of 511 MPa under 44 % porosity, achieving satisfactory rate performance under mass loadings of 37.7 mg cm−2. After 200 cycles at the current density of 2.83 mA cm−2, it can maintain 56 % initial capacity, and the volume expansion is only 8.04 %. This study provides reference values for exploring and preparing high‐mass loading electrodes and the future design of solid‐state battery electrodes. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) dominate the market of rechargeable power sources. To meet the increasing market demands, technology updates focus on advanced battery materials, especially cathodes, the most important component in LIBs. In this review, we provide an overview of the development of materials and processing technologies for cathodes from both academic and industrial perspectives. We briefly compared the fundamentals of cathode materials based on intercalation and conversion chemistries. We then discussed the processing of cathodes, with specific focuses on the mechanisms of a drying process and the role of the binders. Several key parameters for the development of thick electrodes were critically assessed, which may offer insights into the design of next-generation batteries. [ABSTRACT FROM AUTHOR]

The present study is the first to evaluate the spiral ganglion neurons (SGNs) and the linear and angular measurements of the cochlea in temporal bones of cochlear implant (CI) recipients. There are no studies evaluating the morphometric measures in subjects after long-term CI use, and this study fills in this gap in current knowledge, greatly important for the design of CI electrodes. Amira based 3-D reconstructions of the cochlea were generated from stained histopathological slides of 15 celloidin-embedded human temporal bones. The SGN angular distance from the round window exhibited a narrow range from 684°-704°, corresponding to linear distances of 17.87 and 34.48 mm along the inner and outer wall of the scala tympani. The first turn measured an average of 14.21 mm along the inner wall and 23.92 mm along the outer wall. The outer wall average for the second turn was 11.11 mm and for the partial third apical turn was only 4.49 mm. The range for cochlear duct angular distance was 876° to 1051°, with a mean of 2.63 turns, corresponding to an average linear distance of 39.53 mm, ranging from 35.44 mm to 43.57 mm 6 out of 15 temporal bones demonstrated better preservation of SGN in the middle and apical segments of Rosenthal's canal. The present study demonstrates that the anatomy of the cochlea of CI patients does not differ significantly from that of normative subjects and establishes measurements using the round window as the 0° reference point, an important surgical landmark. The relevance of the measurements to cochlear implant design are discussed.

In this work, an electrode was developed to determine the dielectric properties of tissue phantoms using impedance measurements. For this purpose, a coaxial electrode design was selected as the most suitable electrode design. Three tissue phantoms (blood, fat, muscle) were prepared from distilled water, sodium chloride, 1,2-propanediol, agar, and gelatine, and then characterized. Measurements were performed using an impedance analyzer in a range between 1 kHz and 1 MHz. A comparison with literature values showed good correspondance of the permittivity values determined, thus proving the applicability of the electrode design. However, the conductivity values measured were different from literature values. In the future, alteration and minimization of the electrode can be done to further improve the characterization.

Detection sensitivity is a crucial factor in the application of ECIS sensors. For these biosensors, the electrode configuration has a direct impact on sensitivity, yet few studies on monopolar electrodes have been reported. In this study, ECIS sensor arrays, which have a series of working electrode configuration with a wide diameter range and different electrode number, were fabricated to monitor living osteoblast-like MC3T3-E1 cells. The experimental results revealed that when the electrode diameter was larger than 25 μm, electrodes with smaller diameter and number yielded higher impedance values and generated more impedance shift to cell status change. The membrane capacitance obtained by equivalent circuit fitting was at the same level. When the electrode diameter was even smaller, the results in detection of cell monolayer were opposite, and there was no distinct relationship between impedance and membrane capacitance shift to cell status change and electrode geometry. The proposed sensor chip, allowing for a sustained and stable detection of cellular impedance, provides the basis for the selection of the electrode configuration of monopolar electrodes. The test results of electrodes with a diameter of 25 μm and lower indicated the possibility of single cell impedance measurement, which can provide unique insight into the heterogeneous electrical behavior of cells, and, in this case, the electrode size should be close to the cell size. [ABSTRACT FROM AUTHOR]

Electro-optic modulators (EOMs) are crucial devices for modern communication enabling high bandwidth optical communication links. Traveling wave electrodes are used to obtain high-speed modulation in these EOMs. We present the electrode design and analysis along with the study of effects of changing orientation on device performance for a thin-film lithium niobate tunable Mach–Zehnder interferometer (MZI) that offers sub-THz bandwidth operations. High velocity and impedance matching with low RF attenuation, high third-order SFDR (∼121 dB/Hz2/3) and a low half-wave voltage length product (1.74 V.cm) have been achieved for a bandwidth of 136 GHz. High-speed digital modulation using multi-level signal formats (PAM-2, QAM-4 and QAM-16) with low BER for 400 Gbps data has been demonstrated to assess the digital performance of the device. [ABSTRACT FROM AUTHOR]

Magnetoelectric (ME) composites are promising for the development of high-performance magnetometers due to their high sensitivity, low cost, low power consumption, and small size. Enhancing the ME coefficient while reducing the background noise is an effective method to improve the performance of ME sensors, which remains challenging. In this work, we propose a method to reduce the equivalent magnetic noise by optimizing the electrode design and the magnetic annealing process in magnetoelectric quartz/Metglas composites. Compared with the non-optimized ME composites, the ME coefficient increases by 1.38 times while the background noise decreases by about 0.78 times, resulting in a LoD of 10 fT at resonance. Due to the high ME coefficient and low background noise, the equivalent magnetic noise from 20 kHz to 50 kHz was less than 6.10 pT/Hz1/2. The results show that proper annealing treatment of Metglas is beneficial for improving the soft magnetic properties. Meanwhile, the hollow electrode of quartz can reduce the equivalent capacitance and enhance the quality factor of the piezoelectric layer. This work demonstrates a feasible way to enhance the performance of ME magnetic field sensors. [Display omitted] • By electrode design, the equivalent capacitance of quartz is reduced, and the quality factor is improved by 122.83, compared with the quartz with full electrode. For Metglas, the mixture composed is formed after annealing treatment, which results in enhanced soft magnetic performance and low loss. • The ME coefficient of the ME composites reaches up to 81.34 V/Oe. The EMN is lower than 6.10 pT/Hz1/2 over the frequency range of 20 kHz to 50 kHz, and the LoD reaches 10 fT at resonance, which is 10 times smaller than that of the over-treated ME composites. [ABSTRACT FROM AUTHOR]

With the rapid development of portable and wearable electronic devices, research on flexible energy storage devices has gradually shifted to the directions of miniaturization, softness and intelligence. At the same time, people have higher requirements for the energy density, power density and mechanical properties of the device. As the core part of flexible energy storage devices, electrode material is the key to determining device performance. With the development of flexible energy storage electronic devices, there is an urgent need for new battery technology and fast, low cost and precise control of their microstructure preparation methods. Therefore, the research and development of new energy storage devices such as flexible lithium/sodium-ion batteries, flexible lithium-sulfur batteries, and flexible zinc-air batteries have become the current research hotspots in academia. The current research status of flexible energy storage battery electrodes in recent years was discussed in this paper, the design of flexible electrode materials (independent flexible electrodes and flexible substrate electrodes), and the preparation process of flexible electrode materials of different dimensions (one-dimensional materials, two-dimensional materials and three-dimensional materials) and applications of flexible energy storage electrodes (flexible lithium/sodium ion batteries, flexible lithium-sulfur batteries, flexible zinc-air batteries) were compared and analyzed, and the structural characteristics and electrochemical properties of electrode materials were discussed. Finally, the current problems faced by flexible energy storage devices were pointed out, and the future focus of flexible energy storage devices was the research and development of new solid electrolytes, the rational design of device structures and the continuous optimization of packaging technology.

Abstract The electrode structure is a crucial factor for all‐solid‐state batteries (ASSBs) since it affects the electronic and ionic transport properties and determines the electrochemical performance. In terms of electrode structure design, a single‐ion conducting solid polymer electrolyte (SIC‐SPE) is an attractive solid electrolyte (SE) for the composite electrode among various SEs. Although the ionic conductivity of SIC‐SPE is lower than other inorganic SEs, the SIC‐SPE has a relatively lower density and can form an intimate contact between the SE and active materials (AM), resulting in an excellent electrode structure. The electrochemical performance of the cell with SIC‐SPE was comparable with the cell with Li6PS5Cl (LPSCl), which has 10 times higher intrinsic ionic conductivity than SIC‐SPE (SIC‐SPE: 0.2 × 10−3 S cm−1, LPSCl: 2.2 = 10−3 S cm−1 at 25°C). 3D digital‐twin‐driven simulation showed that the electrode with SIC‐SPE has a higher SE volume fraction, a lower tortuosity, and a larger AM/SE contact area than the LPSCl electrode. The favorable structure of the SIC‐SPE electrode leads to lower overpotential than the LPSCl electrode during operation. Our results suggest that the SIC‐SPE is a promising SE for making a good electrode structure in ASSBs.

Proton exchange membrane fuel cells (PEMFCs) help to achieve decarbonized energy demand due to their advantages of no pollution emission and high power efficiency. But the commercialization of fuel cells has encountered difficulties due to the high-cost issue. The key to addressing the cost issue of PEMFCs lies in reducing Pt amount. However, concentration polarization in the high current density region increases as the decrease of Pt loading, of which the local transport loss of oxygen in the cathode catalyst layer (CCL) occupies the most significant part. Therefore, reducing local oxygen transport resistance is necessary to achieve ultra-low Pt loading in practical PEMFC. This paper focuses on summarizing various electrode design methods for the CCL that optimize the local transport resistance of oxygen, including modifications to the ionomer layer, catalyst structure, and overall electrode structure. Each improvement method is explained with the mechanism of the local oxygen transport process, investigating the effect of different ionomer and Pt-based nanoparticle structures, distribution, and surface chemistries on the local transport pathways. The insights proposed in this paper provide recommendations for the fabrication and design of high-efficiency low-platinum fuel cells. • Local oxygen transport process and corresponding influence are illustrated. • Guidance is provided for the future development of ionomer and catalyst materials. • The most recent advances in CL design with low local resistance are summarized. [ABSTRACT FROM AUTHOR]

Self-supported NiCo2O4–NiCoO2 sheathed architectures on nickel foam (NCO-nco/NF), obtained by a two-step hydrothermal, postcalcination treatment, are demonstrated to be an efficient battery-type electrode for supercapacitors. NiCoO2 nanosheets uniformly extend over the NiCo2O4 urchin resulting in a synergistic association wherein the intrinsic redox ability of the scaffold and the sheath's superior hydroxyl adsorption capacity enabled enhanced electrochemical performance compared to a reverse architecture (nco-NCO/NF). Moreover, the NCO-nco/NF composite electrode with a favorable meso–macro porosity gave a high specific charge of 1373 C g–1 (1961 F g–1) with appreciable endurance in KOH electrolyte (5000 cycles). Additionally, an NCO-nco/NF and activated carbon hybrid supercapacitor assembly demonstrated a high energy density of 66.6 W h kg–1 at a power density of 400 W kg–1. The unique electrode design combining the individual attributes of the constituent units offers the possibility of developing high-performing electrode materials for supercapacitor applications. [ABSTRACT FROM AUTHOR]