Applications In Electrochemical Devices Research Articles

Ni6Se5, an unexplored transition metal chalcogenide of formula M(n+1)Xn(2≤n≤8), for high-performance hybrid supercapacitor and Li-ion battery application.

This work reports an in-situ, one-step hydrothermal preparation procedure of a binder-free electrode growth of Ni6Se5on nickel foam (Ni6Se5/NF) with a rod-like structure. Ni6Se5is an enveloped transition metal chalcogenides of formula M(n+1)Xn(where 2≤n≤8, M is a transition metal and X is chalcogen) of the nickel selenide family. The Ni6Se5/NF electrode described here demonstrates an exceptional lifetime of 81% capacitance retention over 20000 cycles and a high specific capacitance of 473.5 Fg-1at a current density of 4 Ag-1. The Ni6Se5/NF/activated carbon asymmetric supercapacitor exhibits a remarkable 97.3 Whkg-1energy density and a 2325 Wkg-1power density. Ni6Se5served as an active electrode material in supercapacitor applications and offered exceptional power density and long cycle life. Ni6Se5/NF, used as an anode for Li-ion batteries (LIB), has a lithium storage capacity of 939.7 mAhg-1at 100 mAg-1current density. Ni6Se5active electrode material's excellent energy storage capability, which was previously unreported, is particularly beneficial for electrochemical energy storage device applications.

Bimetallic cobalt-rich Co0.63Ru0.37 nanoalloys encapsulated in carbon nanofibers expediting oxygen evolution reaction under acidic solution

Electrochemical water splitting holds great promise as a sustainable method for oxygen production through energy conversion. However, the scarcity and limited durability of noble metals like Pt, Ru, and Ir, which exhibit excellent electrochemical activity, impede their practical and large-scale application in electrochemical devices. In order to tackle this issue, we prepared bimetallic single-phase Co0.63Ru0.37 nanoalloys encapsulated in carbon nanofibers (Co0.63Ru0.37/CNFs) for highly efficient water oxidation electrocatalysis. This was achieved through a single-step electrospinning process followed by thermal annealing under an inert atmosphere. Co0.63Ru0.37/CNFs demonstrated exceptional electrocatalytic performance for the oxygen evolution reaction (OER), with an overpotential of only 206 mV at 10 mA cm−2 and a Tafel slope of 46.4 mV dec−1, indicating a high level of activity and long-term stability in acidic solutions. Additionally, Co0.63Ru0.37/CNFs exhibited superior OER performance compared to a commercial benchmark catalyst (cIr, 20 wt% metal loading on Vulcan XC-72) in acidic solutions, highlighting their potential as an efficient OER electrocatalyst for acidic water electrolysis. Furthermore, Co0.63Ru0.37/CNFs offer cost-effectiveness due to their primarily carbon composition, with noble Ru accounting for only half of the total metal content.

A Sustainable Gel Polymer Electrolyte for Solid-State Electrochemical Devices.

Nowadays, solid polymer electrolytes have attracted increasing attention for their wide electrochemical stability window, low cost, excellent processability, flexibility and low interfacial impedance. Specifically, gel polymer electrolytes (GPEs) are attractive substitutes for liquid ones due to their high ionic conductivity (10-3-10-2 S cm-1) at room temperature and solid-like dimensional stability with excellent flexibility. These characteristics make GPEs promising materials for electrochemical device applications, i.e., high-energy-density rechargeable batteries, supercapacitors, electrochromic displays, sensors, and actuators. The aim of this study is to demonstrate the viability of a sustainable GPE, prepared without using organic solvents or ionic liquids and with a simplified preparation route, that can substitute aqueous electrolytes in electrochemical devices operating at low voltages (up to 2 V). A polyvinyl alcohol (PVA)-based GPE has been cast from an aqueous solution and characterized with physicochemical and electrochemical methods. Its electrochemical stability has been assessed with capacitive electrodes in a supercapacitor configuration, and its good ionic conductivity and stability in the atmosphere in terms of water loss have been demonstrated. The feasibility of GPE in an electrochemical sensor configuration with a mediator embedded in an insulating polymer matrix (ferrocene/polyvinylidene difluoride system) has also been reported.

Synthesis of biopolymer electrolyte using sodium alginate with ammonium perchlorate (NH4ClO4) for the application of electrochemical devices

Synthesis of biopolymer electrolyte using sodium alginate with ammonium perchlorate (NH4ClO4) for the application of electrochemical devices

Synthesis and Characterization of Nanomaterials for Application in Cost-Effective Electrochemical Devices

Nanomaterials have gained significant attention as a remarkable class of materials due to their unique properties and the fact that they encompass a wide range of samples with at least one dimension ranging from 1 to 100 nm. The deliberate design of nanoparticles enables the achievement of extremely large surface areas. In the field of cost-effective electrochemical devices for energy storage and conversion applications, nanomaterials have emerged as a key area of research. Their exceptional physical and chemical properties have led to extensive investigations aimed at improving the performance and cost-effectiveness of electrochemical devices, including batteries, supercapacitors, and fuel cells. The continuous development and enhancement of these high-performance materials are driven by the demand for enhanced productivity, connectivity, and sustainability at a reduced cost. This review focuses on the electrochemical performance of electrodes, energy storage, and electrochemical sensors (ES) based on nanotechnology. It discusses the application of nanotechnology in electrochemistry for water purification and the fate of substances in water, while also introducing green nanotechnology and cost-effective, high-fidelity product creation through electrochemical methods. The study emphasizes the synthesis of novel nanomaterials, such as metal–organic frameworks (MOFs), covalent organic frameworks (COFs), and MXenes, with applications in electrochemical devices. Furthermore, it explores the integration of nanostructures with electrochemical systems in economically significant and future applications, along with the challenges faced by nanotechnology-based industries. The paper also explores the interplay between nanomaterials and biosensors, which play a vital role in electrochemical devices. Overall, this review provides a comprehensive overview of the significance of nanomaterials in the development of cost-effective electrochemical devices for energy storage and conversion. It highlights the need for further research in this rapidly evolving field and serves as a valuable resource for researchers and engineers interested in the latest advancements in nanomaterials for electrochemical devices.

Theory‐guided Design of Atomically Dispersed Dual‐Metal Catalysts for Superior Oxygen Reduction Reaction Activity

AbstractThe widespread application of electrochemical energy conversion devices, such as proton exchange membrane fuel cells, is hindered by the kinetically sluggish oxygen reduction reaction (ORR) at the cathode. Transition‐metal and nitrogen codoped carbon materials (TM−N−C) are among the most promising catalysts to solve this problem. Particularly, dual‐metal TM−N−C have already displayed excellent performance. However, further knowledge on the reaction mechanism and the structure−activity relationship is still required. In this study, we established three dual‐metal TM−N−C models (FeMn−N−C, FeCo−N−C, and FeNi−N−C) to investigate the electronic interaction between the metallic sites and their corresponding adsorption strength for oxygenated intermediates in ORR electrocatalysis. Then, using density functional theory calculations, we determined that the ORR activity of the dual‐metal TM−N−C models followed the order of FeCo−N−C > FeNi−N−C > FeMn−N−C. We confirmed the theoretically predicted activity by synthesizing atomically dispersed FeMn−N−C, FeCo−N−C, and FeNi−N−C catalysts using metal‐organic framework precursors, among which FeCo−N−C showed the best results in terms of ORR onset potential and half‐wave potential (0.92 and 0.81 V vs. the reference hydrogen electrode in 0.1 M HClO4, respectively.). The results demonstrate the feasibility of the theory‐guided rational design of efficient dual‐metal catalysts for ORR electrocatalysis.

Directly Imaging and Regulating the Nanoscale Inhomogeneity of S‐Vacancies in Molybdenum Disulfide Monolayer during Electrocatalytic Hydrogen Evolution

AbstractThe study of electron transfer event on two‐dimensional (2D) layered transition metal dichalcogenides has attracted tremendous attentions attributing to their promising applications in electrochemical devices. Herein, we demonstrate an opto‐electrochemical strategy to directly map and regulate electron transfer event on molybdenum disulfide (MoS2) monolayer by combining bright field (BF) imaging technique with electrochemical modulation. The heterogeneity of electrochemical activity on MoS2 monolayer down to nanoscale is resolved spatiotemporally. The thermodynamics of MoS2 monolayer is measured during electrocatalytic hydrogen evolution, and the Arrhenius correlations are obtained. We validate that the defect generation engineered by oxygen plasma bombardment dramatically enhances the local electrochemical activity of MoS2 monolayer, which can be attributed to point defects of S‐vacancies as evidenced. Furthermore, by comparing the difference of electron transfer event on MoS2 with various layers, the interlayer coupling effect is uncovered. This study represents a facile method to image the heterogeneity of electrochemical properties for nanomaterials with atomic thickness and regulate the local activity within the plane by extrinsic factors. It also has potential applications in the design and evaluation of high‐performance layered electrochemical systems down to nanoscale.

Directly Imaging and Regulating the Nanoscale Inhomogeneity of S-Vacancies in Molybdenum Disulfide Monolayer during Electrocatalytic Hydrogen Evolution.

The study of electron transfer event on two-dimensional (2D) layered transition metal dichalcogenides has attracted tremendous attentions attributing to their promising applications in electrochemical devices. Herein, we demonstrate an opto-electrochemical strategy to directly map and regulate electron transfer event on molybdenum disulfide (MoS2 ) monolayer by combining bright field (BF) imaging technique with electrochemical modulation. The heterogeneity of electrochemical activity on MoS2 monolayer down to nanoscale is resolved spatiotemporally. The thermodynamics of MoS2 monolayer is measured during electrocatalytic hydrogen evolution, and the Arrhenius correlations are obtained. We validate that the defect generation engineered by oxygen plasma bombardment dramatically enhances the local electrochemical activity of MoS2 monolayer, which can be attributed to point defects of S-vacancies as evidenced. Furthermore, by comparing the difference of electron transfer event on MoS2 with various layers, the interlayer coupling effect is uncovered. This study represents a facile method to image the heterogeneity of electrochemical properties for nanomaterials with atomic thickness and regulate the local activity within the plane by extrinsic factors. It also has potential applications in the design and evaluation of high-performance layered electrochemical systems down to nanoscale.

Barium Silicate Glasses and Glass–Ceramic Seals for YSZ-Based Electrochemical Devices

The effect of partial SiO2 substitution with Al2O3 and B2O3 on the thermal properties and crystallization of glass sealants in the (50 − x)SiO2–30BaO–20MgO–xAl2O3(B2O3) (wt %) system is studied. It is established that the coefficient of thermal expansion of all obtained glasses lies within a range of 8.2–9.9 × 10−6 K−1. Alumina-doped glasses crystallize after quenching, while samples containing boron oxide are completely amorphous. Magnesium silicates are formed in all glasses after exposure at 1000 °C for 125 h. After 500 h of exposure, a noticeable diffusion of zirconium ions is observed from the YSZ electrolyte to the glass sealant volume, resulting in the formation of the BaZrSi3O9 compound. The crystallization and products of interaction between YSZ ceramics and boron-containing sealants have no significant effects on the adhesion and properties of glass sealants, which makes them promising for applications in electrochemical devices.

Colossal Ionic Conductivity in Interphase Strain-Engineered Nanocomposite Films.

Owing to their wide application in oxide-based electrochemical and energy devices, ion conductors have attracted considerable attention. However, the ionic conductivity of the developed systems is still too low to satisfy the low-temperature application. In this study, by developing the emergent interphase strain engineering method, we achieve a colossal ionic conductivity in SrZrO3-xMgO nanocomposite films, which is over one order of magnitude higher than that of the currently widely used yttria-stabilized zirconia below 673 K. Atomic-scale electron microscopy studies ascribe this superior ionic conductivity to the periodically well-aligned SrZrO3 and MgO nanopillars that feature coherent interfaces. Wherein, a tensile strain as large as +1.7% is introduced into SrZrO3, expanding the c-lattice and distorting the oxygen octahedra to decrease the oxygen migration energy. Combining with theoretical assessments, we clarify the strain-dependent oxygen migration path and energy and unravel the mechanisms for strain-tuned ionic conductivity. This study provides a new scope for the property improvement of wide-range ion conductors by strain engineering.

Graph Theory Design of 3D Printed Conductive Lattice Electrodes

Abstract3D printing has the promising capability to fabricate engineered lattice structures with broadly tunable surface area and optimal geometries for maximizing structural and functional properties. This study characterizes the electrical conductivity of 3D lattices of varying size, structure, and porosity to guide additively manufactured electrode design in energy storage devices. Graph theory‐based calculations and experiments comparing the conductivity of multiple strut lattice structures and illustrating the scaling laws governing architectures with either coated or solid conductive struts are presented. The lightweight lattices explored here show higher conductivity than random foams that lack a periodic mesostructure. It is experimentally demonstrated that the 3D lattice type influences the specific capacity when employed in supercapacitors, outperforming 2D supercapacitor counterparts, and other 3D printed electrodes while allowing for optimization of the design for different energy storage applications. Additionally, it is shown that tuning the physical structure of the lattices allows for precise control over the electrical response to mechanical loading, as confirmed through experimental measurements. The lattice structure programs the electrodes’ mechanical stiffness, with higher relative density samples showing higher Young's modulus. These results can serve to guide the design of 3D printed electrodes in a variety of electrochemical and electromechanical device applications.

Shifting Oxygen Evolution Reaction Pathway via Activating Lattice Oxygen in Layered Perovskite Oxide

AbstractDeveloping high‐performance oxygen evolution reaction (OER) catalysts are critical for the practical application of many electrochemical energy devices. In this study, taking layered perovskite oxide thin films as the model system, it is demonstrated that the OER pathway can be effectively shifted by activating lattice oxygen, leading to strongly enhanced intrinsic activity. The OER performance of Ruddlesden‐Popper (RP)‐phase cobaltite is significantly enhanced as Sr doping at the A site increases, which is attributed to the shift of the reaction pathway from adsorbate evolution mechanism (AEM) to lattice oxygen‐mediated mechanism (LOM). Advanced spectroscopic techniques and density functional theory calculations reveal that the Sr dopant effectively facilitates oxygen ligand hole formation, charge transfer from the oxygen sites, and the formation and migration of oxygen vacancy, hence promoting lattice oxygen to participate in surface reactions. The results provide critical insight into the role of oxygen activity and offer a potential way for constructing highly active electrocatalysts.

Synthesis and characterization of co-precipitated nickel phosphate [Ni3(PO4)2] nanoparticles prepared at varying precursor concentrations

This work investigated the structural, morphological, elemental, optical, and electrochemical characteristics of nickel phosphate nanoparticles co-precipitated at varying molar concentrations. Structural results gave monoclinic crystalline phase with nanorod morphology. EDX plots confirmed deposition of constituent element: nickel, phosphorus and oxygen. The films exhibited good absorbance feature with optical energy band gap values ranging from 1.58 eV to 2.2 eV. Good cyclic reversibility as obtained using 0.1 M of sodium hydroxide as electrolyte. The specific capacitance values of the electrodes ranged from 624.38 F/g to 1017.2 F/g at a scan rate of 1 mV/s. The Ni3(PO4)2 electrode prepared at 0.3 M recorded maximum energy and power densities of 239.49 Wh/kg and 2.52 W/kg respectively. The synthesized samples find potential application in optical and electrochemical devices.

Low-temperature Griffiths phase in chemically synthesized CoMn2O4 spinel oxide

Mixed transition metals and their oxides have gained a myriad of research interests because of their wide applications in electronics, magnetism, and electrochemical energy storage and conversion devices. In this study, we have synthesized CoMn2O4 spinel oxide through the auto-combustion method. At room temperature, the x-ray diffraction technique confirms the tetragonal crystal structure and phase purity. The Fourier transform infrared spectroscopy investigated that the oxide and hydroxyl groups are the major active sites. The absorption bands around 544 cm−1 and 638 cm−1 correspond to the atomic vibration of Co-O and Mn-O in octahedral and tetrahedral sites, respectively. The bandgap confirmed from the UV-Vis spectrum is 1.3 eV, indicating that synthesized sample is near-infrared light active material. The scanning electron microscopy shows that the average particle size of CoMn2O4 is 161 ± 26 nm. X-ray photoelectron spectra suggest a mixed spinel structure comprised of Co and Mn cations. The magnetic investigations revealed that the CoMn2O4 exhibits a ferrimagnetic response. However, the emergence of large exchange bias is observed well above the transition temperature of ∼172 K due to the Griffiths phase. It is proposed that the appearance of Griffiths phase arises due to the presence of antiferromagnetic impurities, which become active at low temperature.

Metal Oxide-Supported Metal Catalysts for Electrocatalytic Oxygen Reduction Reaction: Characterization Methods, Modulation Strategies, and Recent Progress.

The sluggish kinetics of the oxygen reduction reaction (ORR) with complex multielectron transfer steps significantly limits the large-scale application of electrochemical energy devices, including metal-air batteries and fuel cells. Recent years witnessed the development of metal oxide-supported metal catalysts (MOSMCs), covering single atoms, clusters, and nanoparticles. As alternatives to conventional carbon-dispersed metal catalysts, MOSMCs are gaining increasing interest due to their unique electronic configuration and potentially high corrosion resistance. By engineering the metal oxide substrate, supported metal, and their interactions, MOSMCs can be facilely modulated. Significant progress has been made in advancing MOSMCs for ORR, and their further development warrants advanced characterization methods to better understand MOSMCs and precise modulation strategies to boost their functionalities. In this regard, a comprehensive review of MOSMCs for ORR is still lacking despite this fast-developing field. To eliminate this gap, advanced characterization methods are introduced for clarifying MOSMCs experimentally and theoretically, discuss critical methods of boosting their intrinsic activities and number of active sites, and systematically overview the status of MOSMCs based on different metal oxide substrates for ORR. By conveying methods, research status, critical challenges, and perspectives, this review will rationally promote the design of MOSMCs for electrochemical energy devices.

Microbe‐Mediated Biosynthesis of Multidimensional Carbon‐Based Materials for Energy Storage Applications

AbstractBiosynthesis methods are considered to be a promising technology for engineering new carbon‐based materials or redesigning the existing ones for specific purposes with the aid of synthetic biology. Lots of biosynthetic processes including metabolism, fermentation, biological mineralization, and gene editing have been adopted to prepare novel carbon‐based materials with exceptional properties that cannot be realized by traditional chemical methods, because microbes evolved to possess special abilities to modulate components/structure of materials. In this review, the recent development on carbon‐based materials prepared via different biosynthesis methods and various microbe factories (such as bacteria, yeasts, fungus, viruses, proteins) are systematically reviewed. The types of biotechniques and the corresponding mechanisms for the synthesis of carbon‐based materials are outlined. This review also focuses on the structural design and compositional engineering of carbon‐based nanostructures (e.g., metals, semiconductors, metal oxides, metal sulfides, phosphates, Mxenes) derived from biotechnology and their applications in electrochemical energy storage devices. Moreover, the relationship of the architecture–composition–electrochemical behavior and performance enhancement mechanism is also deeply discussed and analyzed. Finally, the development perspectives and challenges on the biosynthetic carbons are proposed and may pave a new avenue for rational design of advanced materials for the low‐carbon economy.

Hierarchical Structures Formed in an Atmospheric Pressure Plasma Jet by Polymerization from an Aerosol of Oxalic Acid Stabilized WO3–x Nanosheet Colloids: Toward High-Performance Electrochemical Devices and Sensors

The development of microstructures which combine high total surface area and high porosity is crucial for technologies such as electrocatalysis, electrochromics, and sensors. High deposition rate, composition control of deposition, and low processing temperature to retain active compositions are also desirable. To this end, this study describes combining colloidal sol chemistry with a nonthermal atmospheric pressure dielectric barrier discharge plasma jet to print hybrid inorganic/organic tungsten trioxide/oxalic acid (WO3–x/OA) microspheres. Injection of an aerosol of oxalic acid stabilized colloidal tungstic acid into an atmospheric pressure plasma jet results in the deposition of spherical structures in which the colloid is trapped within a plasma-polymerized organic shell. Subsequent low-temperature sintering produces hierarchical spherical shell-like structures comprising tungsten oxide nanosheets. Alteration of the gas flow rate changes the composition of the deposited material. The method has promise for the general preparation from colloidal precursors of porous materials of controlled morphology and composition with hierarchical microstructures, such as are required for applications in electrochemical devices and sensors which need a high ratio of surface area to volume and connectivity throughout the structure, yet also need a microstructure which is open for rapid exchange of reactants.

N, S co-doped carbon film wrapped Co nanoparticles for boosting oxygen reduction reaction

Electrochemical energy (e.g., fuel cell and metal-air batteries) is featured by large theoretical energy density, high conversion efficiency, safe operation and pollution-free emission. However, the sluggish dynamics of oxygen reduction reaction (ORR) and high cost of noble metals hinder their widespread commercial applications in electrochemical energy devices. Herein, we present a method for the preparation of the N, S co-doped carbon film wrapped Co nanoparticles (Co/NSC) for ORR by aging and then pyrolyzing the mixture of cobalt salt and 1-(p-Toluenesulfonyl)imidazole. The co-doping of N and S facilitates the electron rearrangement of the carbon film, resulting in a rapid electron transfer. The core-shell structure enhances the interaction between N, S co-doped carbon film and Co nanoparticles. These features endow the Co/NSC catalyst an excellent ORR with a half-wave potential of 0.860 V and limiting current density of 6.2 mA cm-2, besides the superior anti-methanol. The Co/NSC catalyst as the air cathode grants the assembled zinc-air battery high open circuit voltage (1.467 V), large peak power density (156.2 mW cm-2), great specific capacity (747.9 mAh gZn-1), and excellent stability. Thus, the prepared Co/NSC catalyst exhibits a promising application in zinc-air battery. This work provides an approach for the synthesis of the carbon-shell coated non-noble metal catalyst and its subsequent applications in oxygen electrocatalysis.

Scalable and Controllable Synthesis of Pt‐Ni Bunched‐Nanocages Aerogels as Efficient Electrocatalysts for Oxygen Reduction Reaction

AbstractDeveloping efficient and stable Pt‐based oxygen reduction reaction (ORR) electrocatalysts via both economical and controllable routes is critical for the practical application of electrochemical energy devices. Herein, a scalable, controllable, and general ambient‐O2‐involved aqueous‐solution cultivating strategy to prepare PtxMy (M = Ni, Fe, Co) bunched‐nanocages aerogels (BNCs AG) is demonstrated, based on a newly established high‐M‐to‐Pt‐precursor‐ratio‐and‐B‐incorporation‐facilitated M‐rich core and Pt‐rich shell hydrogel formation process. The Pt83Ni17 BNCs AG shows prominent ORR performance with a mass activity (MA) of 1.95 A mgPt−1 and specific activity of 3.55 mA cm−2, which are 8.9‐times and 9.6‐times that of Pt supported on carbon (Pt/C), respectively. Particularly, the Pt83Ni17 BNCs AG displays greatly enhanced durability (MA 82.6% retention) compared to Pt/C (MA 31.8% retention) after a 20 000‐cycles accelerated durability test. Systematic studies including density functional theory calculations uncover that the excellent activity is closely related to the optimized ligand and strain effects with the optimized Ni content in this aerogel; the outstanding durability is endowed by the lowered‐down Ni leaching with the optimized Pt/Ni ratio and the inhibited sintering due to its appropriate porosity. This work provides new perspectives on the development of electrocatalysts with both high performance and low cost.

Treatment of Biowaste for Electrodes in Energy Storage Applications: A Brief Review

Proper and innovative waste management methods still pose a major concern in our present world. Continuous accumulation of biowaste from bio-processing industries, household, organic residues and so on makes the environment polluted and endangers the health of man and other animals. The common waste management methods which include direct dumping into water bodies, open-air combustion, and as land fillers are obsolete and are the major causes of environmental pollution. Conversion of biowastes into valuable materials aids proper waste management, and helps to attain a cleaner environment, in addition to the fact that wastes are turned into wealth. Biowastes are rich in carbon and can serve as excellent precursors for the synthesis of important carbon materials such as activated carbon, graphene, carbon nanotubes etc. Three important methods of converting biowastes into carbon materials are discussed in this review. The electrochemical, adsorption, and electrocatalytic properties of the materials and the applications in electrochemical energy storage devices are also discussed in brief. This review focuses on the synthesis of carbon materials from biowaste residues and their use in developing electrode materials for batteries and supercapacitors. Future perspectives on the need to exploit greener technology for the conversion of biowastes into important carbon materials should be considered.