Large Area Electrodes Research Articles

Accurately prepared the large-area and efficiently 3D electrodes for overall seawater splitting

How to achieve accurately regulation of catalytic electrodes is the challenge of designing high-performance catalytic electrodes. In this work, large area, high stability and excellent conductivity electrode are prepared via one-step mild (298 K) electroplating method and precise control of electroplating parameters on nickel foam (FeNi@NF). The FeNi@NF electrode catalyst the hydrogen/oxygen evolution reaction (HER/OER) in simulate seawater (1.0 M KOH + 0.5 M NaCl), and achieves the current density of 100 mA cm−2 with only 287 mV and 323 mV overpotential. The alkaline electrolyzer drives 100 mA cm−2 for overall water splitting at a low voltage of 1.73 V. More importantly, the catalytic performance durable for more than 5 days at the industrial current density (1000 mA cm−2), and the designed large-area 25.0 cm2 catalytic electrode can achieve stable operation of industrial proton exchange membrane electrolyser. This preparation strategy provides a new idea for the current research of energy engineering and energy storage.

Recycled industrial waste silicon steel as high-performance electrode for oxygen evolution reaction using electroless plating surface modification

Exploring the large-area, cost-effective, and high-performance electrocatalyticoxygen evolution reaction (OER) electrode for water splitting is of great significance. Inspiring from the ‘waste to resource’ toward the circular economy, herein, the waste silicon steels (SS) were transformed into high-performance CoxFe3-xP/SS OER electrode through a facile electroless plating method. The plating layer of CoxFe3-xP not only endows the CoxFe3-xP/SS with outstanding electrocatalytic OER activity but also improves the corrosion resistance and stability of CoxFe3-xP/SS. The obtained Co2Fe1P/SS electrode exhibits the lowest overpotential of 244 mV at a current density of 10 mA/cm2 in 1 M KOH with a low Tafel slope of 48.7 mV/dec. Even at high current densities and in 6 M KOH and alkaline seawater (seawater + 1 M KOH), the Co2Fe1P/SS electrode also shows relatively low overpotentials, as well as high long-term durability. Specially, a large-area Co2Fe1P/SS OER electrode(40 × 40 cm2)was successfully prepared via the electroless plating approach. Toward the CoxFe3-xP/SS, the bimetallic Co-Fe synergies and phosphating effect promote the exposure of active sites and charge transfer. In addition, generated M(OH)x/MOOH (M = Co or Fe) species during OER activation could synergize with CoxFe3-xP and contribute excellent catalytic activity and stability.

Self-Standing Mo/MoO2 Porous Flake Arrays for Efficient Hydrogen Evolution Reaction in High-pH Media.

The alkaline hydrogen evolution reaction (HER) is limited by scarce proton availability, resulting in slower reaction kinetics compared to those under acidic conditions. Enhancing the local chemical environment of protons on the catalyst surface can improve the intrinsic reaction kinetics. Here, we design a Mo/MoO2 metallic heterojunction that creates an acidic-like environment with a proton-rich surface, significantly enhancing HER performance in alkaline electrolytes, as confirmed by in situ spectroscopy and electrochemical analysis. A self-standing Mo/MoO2 catalytic electrode is fabricated via a controlled pyrolysis-reduction strategy. This electrode exhibits exceptional HER activity, with low overpotentials of 65 mV at 10 mA cm-2 and 315 mV at 500 mA cm-2, a Tafel slope of 38.2 mV dec-1, and stability exceeding 60 h at -300 mA cm-2 in alkaline solution. The porous flake array structure of the Mo/MoO2 heterojunctions enhances the adjacent hydronium (H3O+) concentration, resulting in a ΔGH* value of 0.15 eV and a water dissociation energy barrier of 0.37 eV in an alkaline medium. The successful preparation of a large-area electrode (2 cm × 2 cm) demonstrates the scalability of this approach for fabricating molybdenum-based catalytic electrodes with enhanced HER activity in alkaline environments.

Embedded Micro-Interdigitated Flow Fields for Efficient Intercalation-Based Desalination at Seawater Scale

During the past decade, intensifying water crises around the globe have motivated research in electrochemical desalination. Among such technologies, Faradaic deionization (FDI) has shown great promise for seawater desalination with the use of intercalation electrode materials that possess at least ten-fold higher charge storage concentration (~5 M) than seawater salinity (~0.5 M). Despite many efforts focused either on developing electrode materials or modifying flow-cell architectures, the promise of intercalative FDI was not previously realized experimentally. This work demonstrates for the first time salt removal approaching seawater-level salinity by using a flow cell containing symmetric cation intercalation electrodes separated by an anion-exchange membrane [Do et al., Energy Environ. Sci., 16, 3025–3039 (2023)]. We show removal of 96% of salt from ~500 mM NaCl feeds with ~50% water recovery at a thermodynamic energy efficiency (TEE) of 7%. In addition, the flow cell readily produces fresh water (< 0.017 M NaCl) from brackish water with 40% TEE and substantially lowered hypersaline brine concentration from 0.78 M down to 0.23 M at 11.7% TEE. We note that (1) scaling up the charge capacity of intercalation electrodes is crucial to improve salt removal in FDI and (2) rational design of flow-through electrodes is equally important to make FDI more energy-efficient by mitigating pumping energy consumption. Upscaling was achieved by using large-area electrodes with high areal loading of nickel hexacyanoferrate (NiHCF), up to 21 mg cm-2. Pumping energy was drastically reduced by embedding an interdigitated array of 70 µm wide channels into the NiHCF electrodes using laser micromaching to form novel embedded, micro-interdigitated flow fields (eµ-IDFFs). The dimensions of the eµ-IDFFs were tailored for our low-permeability electrodes based on analytical and numerical modeling, resulting in two orders of magnitude improvement in the apparent hydraulic permeability of these electrodes while minimizing active-material loss. Evidence of water transport between diluted and concentrated streams, as well as feed-concentration-dependent charge efficiency were reported, which potentially contributed to energy efficiency and water recovery losses, motivating their investigation to further improve FDI performance. In addition to their application toward desalination, the present eµ-IDFFs show promise for use in electrochemical energy storage and conversion processes that employ nanomaterials

Eco-friendly and large-scale fabrication of NiMoN/Ni(OH)2/NF as highly efficient and stable alkaline hydrogen evolution reaction electrode

Bimetallic nickel-molybdenum nitride (NiMoN) catalysts have attracted great attention due to their remarkable similarity to group VIII noble metals in terms of electronic structure, good electron conductivity, and durability for the hydrogen evolution reaction (HER). However, the existing approaches for fabricating NiMoN catalysts usually entail a series of multiple steps and hazardous ammoniated ingredient. As a result, these methods are difficult to be scaled up for large-area fabrication towards industrial water splitting. Herein, a hierarchical composite NiMoN@Ni(OH)2@NF composite electrode with a sheet morphology was synthesized based on a rational combination of seawater etching and magnetron sputtering. This method is easily scalable for producing large-area electrodes with minimal pollution. The incorporation of Ni(OH)2@NF nanoarray carriers enhances the exposure of additional active sites on the NiMoN layer, thereby augmenting the electrochemically active specific surface area of the electrode.The as-synthesized NiMoN@Ni(OH)2@NF electrode demonstrates excellent HER activity, with an overpotential of 57 mV at 10 mA cm−2, and exhibits remarkable long-term catalytic stability for over 100 h at a current density of 100 mA cm−2.This study presents an eco-friendly and straightforward method for preparing large-scale transition metal nitride catalysts with high catalytic activity.

Optimization of a large-area grid electrode for negative ion source in fusion neutral beam injector

At present, the CRAFT (Comprehensive Research Facility for Fusion Technology) dual-driver negative ion source for neutral beam injection applications has made progress. In order to solve the problem of heat removal function in large-area extraction grid, the multi-physics simulation, manufacturing and testing are carried out. Two simulation conditions before Cs seeding (Je∼350 A/m2, JH-∼50 A/m2) and after sufficient Cs conditioning (Je∼150 A/m2, JH-∼250 A/m2) were considered to evaluate the power load on EG, which peak power density were 11 and 6 MW/m2 respectively and were concentrated on locate near the two aperture rows. This paper mainly studies three designs of minor cooling channels (double bending channels, double straight channels, and single straight channel). First, the grid temperature, thermal stress and thermal deformation are compared with an inlet water rate of 1.21 kg/s at 35 °C, and the channel forming methods and welding types mechanisms are compared. The simulation results show that the thermos-mechanical property of double bending channels is the best, and that of double straight channels is slightly worse. In terms of processing and manufacturing, the yield of double bending channels is lower than double straight channels, and it is easy to leak during the experiment.

Metal assisted chemical etching derived reusable and scalable production of large-area Ag nanowire-based flexible transparent electrodes for electrochromic Zn-ion battery

To advance polydimethylsiloxane (PDMS)-supported silver nanowires (Ag NWs) based flexible and transparent electrodes (AgNWs/PDMS), innovative patterning techniques are essential for enabling large-area fabrication with cost-effective reusability features. Here, we introduce a metal assisted chemical etching (MACE) protocol for patterning Si wafers, allowing the repetitive fabrication of large-sized AgNWs/PDMS electrodes with controlled penetration depth for the first time. To the best of our knowledge, MACE technology has not previously been employed for fabricating AgNWs/PDMS electrodes. Through the careful selection of etchant, etching time, and suitably doped Si wafers (n-type and p-type), the resulting AgNWs/PDMS electrodes offer favorable optical, electrical and flexiblity characteristics. The electrodes deliver a sheet resistance of 18 Ω‧sq−1 at 88 % transmittance (550 nm) while retaining 93.18 % transmittance with only a 7 Ω‧sq−1 resistance increase after 10,000 bending cycles (3 mm). The penetration depth control offered by this method ensures impressive mechanical durability without additional post-processing. Moreover, the etched Si wafers can be reused multiple times, reducing overall costs. The sizes of AgNWs/PDMS electrodes produced using this method depend entirely on the Si wafer size, allowing scalability by employing larger wafers. As a proof-of-concept, we also demonstrate the fabrication of a robust, flexible, electrochromic zinc ion battery utilizing the AgNWs/PDMS electrodes developed in this study.

DC-free Method to Evaluate Nanoscale Equivalent Oxide Thickness: Dark-Mode Scanning Capacitance Microscopy.

This study developed a DC-free technique that used dark-mode scanning capacitance microscopy (DM-SCM) with a small-area contact electrode to evaluate and image equivalent oxide thicknesses (EOTs). In contrast to the conventional capacitance-voltage (C-V) method, which requires a large-area contact electrode and DC voltage sweeping to provide reliable C-V curves from which the EOT can be determined, the proposed method enabled the evaluation of the EOT to a few nanometers for thermal and high-k oxides. The signal intensity equation defining the voltage modulation efficiency in scanning capacitance microscopy (SCM) indicates that thermal oxide films on silicon can serve as calibration references for the establishment of a linear relationship between the SCM signal ratio and the EOT ratio; the EOT is then determined from this relationship. Experimental results for thermal oxide films demonstrated that the EOT obtained using the DM-SCM approach closely matched the value obtained using the typical C-V method for frequencies ranging from 90 kHz to 1 MHz. The percentage differences in EOT values between the C-V and SCM measurements were smaller than 0.5%. For high-k oxide films, DM-SCM with a DC-free operation may mitigate the effect of DC voltages on evaluations of EOTs. In addition, image operations were performed to obtain EOT images showing the EOT variation induced by DC-stress-induced charge trapping. Compared with the typical C-V method, the proposed DM-SCM approach not only provides a DC-free approach for EOT evaluation, but also offers a valuable opportunity to visualize the EOT distribution before and after the application of DC stress.

Nucleation of Pitting and Evolution of Stripping on Lithium-Metal Anodes.

The stripping reaction of lithium (Li) will greatly impact the cyclability and safety of Li-metal batteries. However, Li pits' nucleation and growth, the origin of uneven stripping, are still poorly understood. In this study, we analyze the nucleation mechanism of Li pits and their morphology evolution with a large population and electrode area (>0.45 cm2). We elucidate the dependence of the pit size and density on the current density and overpotential, which are aligned with classical nucleation theory. With a confocal laser scanning microscope, we reveal the preferential stripping on certain crystal grains and a new stripping mode between pure pitting and stripping without pitting. Descriptors like circularity and the aspect ratio (R) of the pit radius to depth are used to quantify the evolution of Li pits in three dimensions. As the pits grow, growth predominates along the through-planedirection, surpassing the expanding rate in the in-plane direction. After analyzing more than 1000 pits at each condition, we validate that the overpotential is inversely related to the pit radius and exponentially related to the rate of nucleation. With this established nucleation-overpotential relationship, we can better understand and predict the evolution of the surface area and roughness of Li electrodes under different stripping conditions. The knowledge and methodology developed in this work will significantly benefit Li-metal batteries' charging/discharging profile design and the assessment of large-scale Li-metal foils.

On-Chip Micro-Supercapacitor with High Areal Energy Density Based on Dielectrophoretic Assembly of Nanoporous Metal Microwire Electrodes.

Advances in the Internet of Things (IoT) technology have driven the demand for miniaturized electronic devices, prompting research on small-scale energy-storage systems. Micro-supercapacitors (MSCs) stand out in this regard because of their compact size, high power density, high charge-discharge rate, and extended cycle life. However, their limited energy density impedes commercialization. To resolve this issue, a simple and innovative approach is reported herein for fabricating highly efficient on-chip MSCs integrated with nanoporous metal microwires formed by dielectrophoresis (DEP)-driven gold nanoparticle (AuNP) assembly. Placing a water-based AuNP suspension onto interdigitated electrodes and applying an alternating voltage induces in-plane porous microwire formation in the electrode gap. The DEP-induced AuNP assembly and the gold microwire (AuMW) growth rate can be adjusted by controlling the applied alternating voltage and frequency. The microwire-integrated MSC (AuMW-MSC) electrically outperforms its unmodified counterpart and exhibits a 30% larger electrode area, along with 72% and 78% higher specific and areal capacitances, respectively, than a microwire-free MSC. Additionally, AuMW-MSC achieves maximum energy and power densities of 3.33 µWh cm-2 and 2629 µW cm-2, respectively, with a gel electrolyte. These findings can help upgrade MSCs to function as potent energy-storage devices for small electronics.

Electrodeposited Large-Area Nickel-Alloy Electrocatalysts for Alkaline Hydrogen Evolution under Industrially Relevant Conditions

Developing efficient water splitting electrocatalysts plays a critical role in lowering the energy cost for hydrogen production, which requires accurate evaluation of the catalytic performance especially under industrially relevant conditions. In this work, we design a two-chamber electrolyzer testing system simulating practical water electrolyzer system to enable catalytic performance evaluation under industrially relevant conditions. A one-step electrodeposition method is used to synthesize binary and ternary Ni alloy HER catalysts and the catalytic electrodes are screened and optimized with the two-chamber electrolyzer testing system. A voltage of 1.64V without iR compensation at a current density of 200mA/cm2 is obtained with continuous operation for 70h. Different HER activity trend is observed from conventional three-electrode experiments with low-concentration alkaline electrolytes at room temperature and the two-chamber electrolyzer measurements, further supporting the importance of catalytic performance evaluation under industrially relevant conditions. The electrodeposition synthesis method is further used to prepare large-area catalytic electrodes over 400 cm2 with good uniformity.

Electrostatic catalysis of a click reaction in a microfluidic cell

Electric fields have been highlighted as a smart reagent in nature’s enzymatic machinery, as they can directly trigger or accelerate chemical processes with stereo- and regio-specificity. In enzymatic catalysis, controlled mass transport of chemical species is also key in facilitating the availability of reactants in the active reaction site. However, recent progress in developing a clean catalysis that profits from oriented electric fields is limited to theoretical and experimental studies at the single molecule level, where both the control over mass transport and scalability cannot be tested. Here, we quantify the electrostatic catalysis of a prototypical Huisgen cycloaddition in a large-area electrode surface and directly compare its performance to the conventional Cu(I) catalysis. Our custom-built microfluidic cell enhances reagent transport towards the electrified reactive interface. This continuous-flow microfluidic electrostatic reactor is an example of an electric-field driven platform where clean large-scale electrostatic catalytic processes can be efficiently implemented and regulated.

A low-cost and large-area modular nickel electrode on aramid fabric for efficient solar-driven water electrolysis

We demonstrate a water electrolysis device consisting of two 10 cm2 Ni/aramid flexible electrodes with a Si solar cell with &gt;13% solar-to-hydrogen efficiency over 120 hours stability.

Conformal Electrodeposition of Mesoporous Silica over High Aspect Ratio (AR>100) Nanomesh Electrodes

The high surface area provided by the nanopores of ordered mesoporous silica thin films enables a wide range of electrochemical applications such as sensors, catalysis, energy storage and ion-selective membranes. Further improvements are possible by coating such thin films on large surface area electrodes with high aspect ratios (> 100) to increase the active surface area. Atomic layer deposition (ALD) is often preferred to deposit conformal thin film oxides on high aspect ratio structures. Such vapor-phase depositions are limited by the available surface reactive sites to deposit thin films of thickness ranging from sub-nanometer to few tens of nanometer. However, there is a tradeoff in terms of deposition time/cycles to achieve quality films especially when high aspect ratios (>100) substrates are introduced. Electrochemistry offers an alternative, versatile method to conformally coat layers on 3D electrode surfaces. The electrochemically assisted self-assembly (EASA) of mesoporous silica, utilizes electrochemical reactions to locally increase the pH near the electrode surface, which in turn catalyzes the silica gelation and surfactant self-assembly, thus causing the controlled growth of mesoporous silica thin films [1]. Recently, our group has shown that good quality mesoporous silica films with thickness between 20-2000 nm could be achieved by controlling the hydrodynamic layer in a rotating disc electrode setup [2]. Moreover, EASA of mesoporous silica offers meso-channels that are aligned perpendicular to the underlaying conductive substrate which is optimal for mass-transport.In this follow-up work, we demonstrate a reliable, electrochemically controlled, conformal deposition of mesoporous silica onto large surface area nanomesh electrodes with an aspect ratio close to 100. Nanomesh electrodes developed in our group at imec, is built up of a regularly spaced (50 nm), inter-connected network of vertical and horizontal nanowires of diameter ~40 nm. These electrodes offer an 80x area enhancement (80 cm2 per geometric cm2) while maintaining a porosity close to 75%. We show that, the extent of silica deposition over these nanomesh electrodes can be electrochemically controlled from conformal coatings (~10 nm thick) uniformly coating the whole nanomesh architecture to complete fill and overfill of the nanomesh electrodes (~4 µm thick). Furthermore, excellent mass-transport properties of various silica coated nanomesh electrodes has been demonstrated using a ruthenium hexaammine redox probe. Finally, the area enhancement offered by the silica coated Ni nanomesh is demonstrated using the characteristic accumulation of a positively charged [Ru(NH3)6]3+ probe within the negatively charged silica nanochannels, which shows 55x increase for the amount of charge from the probe stored in the coated nanomesh, compared to a planar silica layer, consistent with the expected surface area enhancement of the 4 µm thick nanomesh electrodes.

Scalable Production of Nickel-Cobalt Based Anode Materials for Alkaline Electrolysis: A Multi-Technique Approach from Micro Powder Analysis to Electrochemical Performance

The growing concern about environmental degradation caused by the use of conventional fossil fuels has triggered a significant paradigm shift in the research and development of sustainable energy sources such as hydrogen. Water electrolysis is a promising approach for achieving efficient energy conversion and storage [1]. While this process has made significant advancements recently, an in-depth understanding of the entire process chain from commercial powder materials to electrodes and their electrocatalytic activity with useful correlations between involved steps are still underexplored.Here our research aims toward a thorough and continuous evaluation of Ni-Co-O-based electrocatalysts to parameterize the process chain to unravel interdependencies and understand the correlation between the material, manufacturing process, electrode structure and final cell performance. The applied methodology incorporates various complementary techniques to analyze the physical and chemical properties of the materials involved consistently throughout the entire process chain. After preliminary characterization of commercial Ni-Co-O micropowder using transmission electron microscopy and energy-dispersive X-ray spectroscopy, ink formulations, obtained from the powder, were optimized using analytical centrifugation [2] and Hansen parameter calculations [3]. Then selected inks were transferred to electrodes by coating these inks on Ni plates via ultrasonic spray deposition. Effect of post-treatments such as vacuum annealing and surface plasma treatment on the electrode stability against delamination was also investigated. To quantify micro features of large electrode areas and analyze their surface characteristics, we developed a framework by employing atomic force microscopy. So evaluated electrodes were finally tested for their functionality as anodes for alkaline water electrolysis where useful correlations were established between the properties of the catalyst ink/ coated electrodes and their electrochemical activity/ stability. In agreement to the identified structural features, our preliminary results indicate that plasma treated Ni-Co-O electrodes show lower overpotentials and higher stabilities in comparison with the pristine and vacuum annealed electrodes due to increased adhesion and surface properties (roughness etc.) induced by plasma.This study highlights the need for careful evaluation of the entire process chain at various stages with knowledge feedback from previous steps for continuous electrode improvisation. Optimization of each individual step is crucial to enhance the final performance of the catalyst. In our future attempts, we plan to scale-up our approach to larger electrode areas (up to 100x100 cm2) where a systematical analysis and optimization of all involved steps can be easily adapted closer to industrial settings. Wang, S., A. Lu, and C.-J. Zhong, Hydrogen production from water electrolysis: role of catalysts. Nano Convergence, 2021. 8: p. 1-23.Bapat, S., et al., On the state and stability of fuel cell catalyst inks. Advanced Powder Technology, 2021. 32(10): p. 3845-3859.Anwar, O., et al., Hansen parameter evaluation for the characterization of titania photocatalysts using particle size distributions and combinatorics. Nanoscale, 2022. 14(37): p. 13593-13607. Figure 1

Enhancing Material Analysis with Statistical and Computer Vision Techniques: A Comprehensive Approach for Evaluating Electrode Quality

The optimization of electrodes for electrocatalysis is critical to the efficient operation of energy conversion applications, i.e., performance and efficiency can be improved by optimizing their fabrication process [1]. In the surface microstructure of anodes has been recognized as a fundamental aspect influencing their functionality [2]. Consequently, it is vital to precisely characterize the microstructure of electrodes. Atomic force microscopy (AFM) has demonstrated to be a potent technique for scrutinizing the nanoscale microstructure of anodes. Nevertheless, AFM has limitations in investigating vast areas, thereby posing a challenge when evaluating the surface microstructure of large-scale electrodes.In this study, we developed a multi-stage data quantification method to overcome the limitations of AFM to measure large electrode areas. The efficacy of the developed approach that combines statistical analysis and computer vision techniques was validated by scrutinizing anodes made under various spray coating process conditions. The results demonstrated that the proposed method facilitated the in-depth evaluation of the degree of homogeneity, surface smoothness, and the presence of cracks or defects, thereby enabling a comprehensive assessment of electrode quality. It was possible to establish structure-performance relationships and delineate the interdependence between surface morphology and anode performance, activity, and cycling stability by combining surface analysis measurements with electrochemical analysis.In conclusion, this link between surface and electrochemical analysis will provide critical insights into anode performance and, in turn, drive the development of advanced materials for energy conversion technologies. Therefore, we believe our method has a high potential to expand the material scientist's toolkit and extend its application to analyze the micro/nanostructure of diverse materials in a wide range of applications, providing novel insights for their optimization. References Siegmund, D., et al., Crossing the valley of death: from fundamental to applied research in electrolysis. Jacs Au, 2021. 1(5): p. 527-535.Chatenet, Marian, et al. "Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments." Chemical Society Reviews (2022).

Impact of dynamic density decay of growing carbon nanotube forests on electrical resistivity

Vertically aligned carbon nanotube (CNT) forests densely formed on diverse metallic substrates are desirable as large-area electrodes and thermal interface materials. In this study, we achieved high-density CNT forests on stainless steel and Cu substrates by preventing the interaction between the metallic elements and Fe catalysts at high temperatures. We found that coating the substrate surface with a combination of Ta and SiO2 effectively suppressed the diffusion of metallic elements of the substrate to the catalytic layer. The macroscopic electrical resistivity of longer forests was found to increase as the number density of CNTs decreased during the growth process. This increase in resistivity was reproduced by the dynamic density decay model in which CNT density decreases with forest growth. We point out the importance of the relationship between the length and density of CNT forests for applications.

Playdough-like carbon electrode: A promising strategy for high efficiency perovskite solar cells and modules

Carbon-based perovskite solar cells (C-PSCs) are promising candidates for large-scale photovoltaic applications due to their theoretical low cost and high stability. However, the fabrication of high-performance C-PSCs with large-area electrodes remains challenging. In this work, we propose a novel playdough-like graphite putty as top electrode in the perovskite devices. This electrode with soft nature can form good contact with the hole-transporting layer and the conductive substrate at room temperature by a simple pressing technique, which facilitates the fabrication of both small-area devices and perovskite solar modules. In this preliminary research, the corresponding small devices and modules can achieve efficiencies of 20.29% (∼0.15 ​cm2) and 16.01% (∼10 ​cm2), respectively. Moreover, we analyze the limitations of the optical and electrical properties of this playdough-like graphite electrode on the device performance, suggesting a direction for further improvement of C-PSCs in the future.

Disposable Electrochemical Sensor Based on MXene/Graphene Nanoplatelets/Ionic Liquid for the Determination of Anticancer Drug Imiquimod

This study describes the development of a novel, ultrasensitive, and selective electrochemical sensor to determine imiquimod (IMQ) using a screen-printed carbon electrode (SPCE) modified with MXene (Ti3C2Tx), graphene nanoplatelets, and ionic liquid (Ti3C2Tx/GNPs/IL). This work reveals the synergistic effect of Ti3C2Tx, GNPs, and IL, where Ti3C2Tx and GNPs provide a large active electrode area and excellent electron transport, and IL exhibits remarkable electrocatalytic behavior. Benefiting from the excellent electrochemical properties of the composite, the developed sensing platform enabled superior electrochemical performance for IMQ in the broad linear range of 0.071–92.0 μM (R2 = 0.999) with a limit of detection (LOD) of 0.487 nM and a detection sensitivity of 7.558 μA μM−1 cm−2. Meanwhile, the sensor has shown good repeatability, reproducibility, stability, and anti-interference ability and has been subsequently used to detect IMQ in cream formulations with satisfactory recoveries (98.33%–99.34%) and lower relative standard deviations (<3%). The findings indicate that the newly developed sensor can contribute to the development of a portable, robust, and high-performance sensing strategy for multidisciplinary targets.

Direct In Situ Determination of the Surface Area and Structure of Deposited Metallic Lithium within Lithium Metal Batteries Using Ultra Small and Small Angle Neutron Scattering

AbstractDespite being the major cause of safety and performance issues in lithium metal batteries, experimental difficulties in quantifying directly the morphology of lithium deposited at electrode surfaces have meant that the mechanism of metallic lithium growth within batteries remains elusive. This study demonstrates that quantitative detail about the morphology of metallic lithium within batteries can be derived non‐destructively and directly using in situ ultra‐small and small‐angle neutron scattering. This information is obtained over a large electrode area in cells where lithium deposition processes are typical of real‐world applications. Complex variations of surface area and interfacial distances 1–10 µm and 100–300 nm are revealed in size that are influenced by current density and cell cycling history, providing valuable insight into the growth of metallic lithium features detrimental to battery performance. Such quantitative insight into the process of lithium growth is required for the development of safer high‐performance lithium metal batteries.