High Electrochemical Performance Research Articles

Highly efficient electrocatalytic degradation of methylparaben using BiOx-doped Ti/β-PbO2 anode: Comprehensive electrochemical study and degradation mechanism

Electrochemical degradation of methylparaben (MPB) was successfully performed using Ti/β-PbO2-BiOx anode. The structure of the fabricated electrode was characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and mapping techniques. The results confirmed the successful preparation of the electrode with favorable morphological and structural properties. This research includes optimization of operating parameters such as solution pH, applied current density, initial MPB concentration and electrolysis time. The results indicate that the prepared electrode has high electrochemical performance and thermal stability. Under optimal conditions, current density of 4.8 mA/cm2, pH = 5 and initial concentration of 0.5 mM, the maximum degradation efficiency of 98.9 % was obtained. In this work, also, based on the data obtained from LC-MS analysis, a detailed mechanism for the degradation of MPB was proposed. In another section of this research, the electrochemical behavior of MPB on glassy carbon electrode was comprehensively studied using cyclic voltammetry at different pH values. The data obtained from this study provide significant insight into the electrochemical behavior of MPB, its pH-dependent properties and adsorption activities. The results of this section can also be used to better optimize the conditions of MPB degradation.

Empowering lithium-ion batteries: The potential of 2D o-Al2N2 as an exceptional anode material through DFT analysis

Finding an appropriate new anode material with high electrochemical performance for lithium-ion batteries (LIBs) is considered one of the significant challenges for both the academic and industrial research communities. Herein, we propose to explore the efficiency of a newly designed two-dimensional (2D) material, named orthorhombic dialuminium dinitride (o-Al2N2), as an alternative anode material for LIB systems through first-principles calculations and ab initio molecular dynamics (AIMD) simulations. The obtained results show that orthorhombic-Al2N2 exhibits a high specific capacity of 1144.2913 mAhg−1, an operating voltage around 0.575 V, and a low kinetic diffusion barrier of 0.26 eV. These results prove the suitability of the o-Al2N2 monolayer as a promising anode material for LIBs with high structural stability, strong binding energy towards lithium adsorbent, fast lithium diffusion, and a high theoretical capacity. These features rank the 2D o-Al2N2 monolayer among the best choices for the anode part of the next-generation rechargeable LIBs.

Novel NASICON-type Mn0.5Ti2(PO4)3@F-doped carbon composite with high electrochemical performance as anode materials for potassium-ion batteries

Mn0.5Ti2(PO4)3 with a NASICON structural is used as an anode material in potassium-ion batteries due to its abundance of vacancies that can hold potassium ions. This characteristic not only contributes to its excellent stability but also results in a high specific capacity. However, the poor electrical conductivity of the polyanionic type structure limits the material's ability to fully utilize its capacity. In this paper, the conductivity and electrochemical stability of the Mn0.5Ti2(PO4)3 anode material are enhanced through composite formation with an F-doped carbon layer. The introduction of F into the carbon matrix creates a large number of vacancy defects and F active sites. The vacancies enhance the transport of potassium ions on the Mn0.5Ti2(PO4)3 material's surface, while the active sites exhibit strong electronegativity, improving the absorption of potassium ions. Therefore, the diffusion impedance of potassium ions is significantly reduced, leading to an increased diffusion rate of potassium ions. Attributing to the improved reaction kinetics, the Mn0.5Ti2(PO4)3@F-doped carbon composite demonstrates a high specific capacity of 86 mA h g−1 at 10,000 mA g−1 when used as the anode for potassium-ion batteries. Even more, the specific capacity remains a capacity of 136 mA g−1 after 3000 cycles at 1000 mA h g−1. This study enhances our comprehension of material design by investigating the alteration of carbon matrix to promote the electrochemical characteristics of materials.

Improving the rate and cycle performance of V-based cathodes through regulation of the Zn2+ desolvation process

The large-scale application of vanadium in AZIBs has been hampered by its inferior rate performance and cycling stability, arising from the desolvation penalty of Zn2+ and the dissolution of vanadium. To address this issue, hydroxymethyl zinc phosphates Zn(O3PCH2OH) (ZnOPC) have been innovatively employed as a cathode electrolyte interphase (CEI) material to enhance the electrochemical performance of V2O5·nH2O (VO) cathode. The organized path structure of ZnOPC, coupled with its numerous hydroxyl groups, significantly reduces the desolvation penalty of Zn[H2O]62+ by forming new hydrogen bonds with the solvent-shell water molecules. More importantly, ZnOPC effectively mitigates vanadium dissolution by immobilizing free H2O which comes from the desolvation of Zn[H2O]62+. Consequently, the modified VO cathode exhibits superior rate performance and extraordinary cycling life, maintaining a specific capacity of 202.7 mAh/g after 7000 cycles at 10 A/g and 238.1 mAh/g at the high current of 20 A/g. These results offer a new prospect for designing high electrochemical performance vanadium-based cathode for AZIBs.

Exploring new solid electrolyte support matrix materials for molten carbonate fuel cells (MCFCs)

New oxide ion conductors with perovskite structures containing alkali metal were explored for use as solid support materials for MCFCs (molten carbonate fuel cells). The conductivity of two candidates, BNT (0.94Bi0.5Na0.5TiO3-0.06BaTiO3) and LNT (La0.5Na0.5TiO3), in an oxidation atmosphere, were measured and compared. The conductivity measurement of BNT in a reducing atmosphere indicated the reduction of BNT to Bi metal by a sharp change in conductivity. It limited the lifetime of the fuel cell using BNT as solid support. Fuel cell measurements using the alternative perovskite LNT showed excellent stability under fuel cell operation conditions and high-power density compared to conventional MCFC with LiAlO2 as the solid matrix. The reason for obtaining high electrochemical performance using the LNT matrix is discussed.

Electrochemical performance of V2O5/TiO2 nanocomposite: As an emerging electrode material for supercapacitor application

This scrutiny encounters the hydrothermal approach of binary nanocomposites V2O5/TiO2 (VT). The XRD pattern substantiated the formation of the binary composites with 18 nm of the crystallite size without any extraneous impurities. Whereas, HR-SEM implies the efficient bonding and homogeneous distribution between V2O5 and TiO2 nanoparticles, which provokes high electrochemical performances. Additionally, the BET analysis exposes the specific surface area to be 251 m2 g−1 with an average pore size of 3.14 nm for the VT nanocomposite. The electrochemical performances of the binary VT nanocomposite exhibit high specific capacitance of 443.7 Fg−1 at a current density of 1 Ag−1 with an excellent cyclic retention of 90 % even after successive 5000 cycles at 5 Ag−1. Therefore, the results obtained in this study clearly demonstrates that the binary nanocomposite VT would be a favorable electrode material for the commercial energy storage applications.

Tuning the composition of CuO/Cu2O composite powders via solution combustion method for supercapacitor application

In this work, the solution combustion synthesis method was implemented as a facile and in-situ procedure to adjust the composition of CuO/Cu2O composite by controlling the amounts of citric acid as fuel. Furthermore, the role of the Cu2O phase on the electrochemical properties was evaluated by preparation the single-phase CuO powders through calcination the CuO/Cu2O composite powders. The structural and microstructural results have shown that the synergic effects of Cu2O and CuO increased the electrochemical performance, including specific capacitance of 842 Fg−1 at 1 Ag−1 and high rate capability of 88 % by increasing the current density to 5 Ag−1. Furthermore, the CuO/Cu2O//activated carbon capacitor exhibited high electrochemical performance, such as an energy density of 27 Wh kg−1 at a power density of 1500 W kg−1 and outstanding cycling stability with 82 % capacitive retention for 2000 charge/discharge cycles, indicating a great potential for the practical application of CuO/Cu2O composite powders.

Preparation of Few-Layered MoS2 by One-Pot Hydrothermal Method for High Supercapacitor Performance.

Molybdenum disulfide (MoS2), a typical layered material, has important applications in various fields, such as optoelectronics, catalysis, electronic devices, sensors, and supercapacitors. Extensive research has been carried out on few-layered MoS2 in the field of electrochemistry due to its large specific surface area, abundant active sites and short electron transport path. However, the preparation of few-layered MoS2 is a significant challenge. This work presents a simple one-pot hydrothermal method for synthesizing few-layered MoS2. Furthermore, it investigates the exfoliation effect of different amounts of sodium borohydride (NaBH4) as a stripping agent on the layer number of MoS2. Na+ ions, as alkali metal ions, can intercalate between layers to achieve the purpose of exfoliating MoS2. Additionally, NaBH4 exhibits reducibility, which can effectively promote the formation of the metallic phase of MoS2. Few-layered MoS2, as an electrode for supercapacitor, possesses a wide potential window of 0.9 V, and a high specific capacitance of 150 F g-1 at 1 A g-1. This work provides a facile method to prepare few-layered two-dimensional materials for high electrochemical performance.

Preparation of Ni Nanowires Covalent Organic Framework Composites with High Electrochemical Stability and Supercapacitor Performance

Preparation of Ni Nanowires Covalent Organic Framework Composites with High Electrochemical Stability and Supercapacitor Performance

Proton‐conducting hydrogel electrolytes with tight contact to binder‐free MXene electrodes for high‐performance thermally chargeable supercapacitor

AbstractThermally chargeable supercapacitors (TCSCs) have offered exceptional energy‐converting efficiency for absorbing human epidermal heat and generating and storing electrical energy, which then realize continuous power supply to electronic devices, such as sensors and wearable electronic products, in a wide range of practical significance. Here, we proposed a flexible TCSC by attaching binder‐free Ti3C2Tx MXene@PPy electrodes on both ends of the H3PO4@P(AM‐co‐AA‐co‐AYP K+) hydrogel electrolyte, which exhibits a large thermal power of 35.2 mV K−1 at 50% relative humidity and maximum figure of merit of 2.1. The high performances of the fabricated devices can be attributed to the tunable electrical, thermodynamic, thermoelectric, and mechanical properties of the hydrogel electrolyte by adjusting the acid content and the proportion of zwitterionic compound AYP K+ in the hydrogel, and the high photothermal conversion efficiency and electrochemical performance of the electrodes. Moreover, the stable and outstanding thermofvoltage output (∼200 mV) under different time scenarios of the TCSC makes it possible to drive a strain sensor, accomplishing the objectives of a human activity monitor.

Non-Enzymatic Glucose Sensors Composed of Polyaniline Nanofibers with High Electrochemical Performance.

The measurement of glucose concentration is a fundamental daily care for diabetes patients, and therefore, its detection with accuracy is of prime importance in the field of health care. In this study, the fabrication of an electrochemical sensor for glucose sensing was successfully designed. The electrode material was fabricated using polyaniline and systematically characterized using scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and UV-visible spectroscopy. The polyaniline nanofiber-modified electrode showed excellent detection ability for glucose with a linear range of 10 μM to 1 mM and a detection limit of 10.6 μM. The stability of the same electrode was tested for 7 days. The electrode shows high sensitivity for glucose detection in the presence of interferences. The polyaniline-modified electrode does not affect the presence of interferences and has a low detection limit. It is also cost-effective and does not require complex sample preparation steps. This makes it a potential tool for glucose detection in pharmacy and medical diagnostics.

Improved interfacial stability of all-solid-state batteries using cation-anion co-doped glass electrolytes

The electrochemical performance of all-solid-state batteries needs to be improved by addressing the poor stability against the lithium metal anode and the high interfacial resistance at the cathode–solid electrolyte interface. Here, metal halide-doped Li7P2S8I–type (LPSI) solid electrolytes are synthesized that improve the electrochemical performance of all-solid-state batteries. The solid electrolytes exhibit a higher ionic conductivity value of 7.77 mS cm−1 than bare LPSI solid electrolytes of 3.96 mS cm−1, at room temperature. The metal halide-doped LPSI solid electrolyte is also stable against the lithium metal anode, with a calculated critical current density value of 1 mA cm−2. The fabricated all-solid-state battery shows high electrochemical performance with 99.2% specific capacity retention after 250 cycles at a 0.5 C rate. The results of post galvanostatic charge–discharge analysis confirms that the proposed metal halide-doped LPSI solid electrolyte exhibits improved interfacial stability compared to bare LPSI solid electrolytes.

Eco-friendly synthesis of nanoceria using orange peel extract for electrochemical detection of selective cadmium ions

Contamination of drinking water and food by cadmium ions (Cd2+) is a major threat to human health and environment. Here, we focus on the fabrication of simple, cost effective, eco-friendly synthesis of Cerium oxide nanoparticles (nanoceria) using orange peel extract for selective detection of cadmium (Cd2+) ions. The green synthesized nanoparticles exhibited cubic structure which was confirmed by XRD studies. The FESEM and EDS image confirm the surface morphology and elemental composition of nanoceria. HRTEM possesses the cubic structure with an average particle size of 17 nm. The green synthesized nanoceria shows a strong absorption Raman spectrum at 465 cm−1. Furthermore, the Electrochemical profile of nanoceria was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The electroactive surface area recorded for CeO2 modified GCE is 13.24 cm2. The nanoceria modified Glassy carbon electrode (GCE) was used for the detection of toxic heavy metal Cd2+ ion with square wave voltammetry. The linear detection range of Cd2+ was from 10 µM to 1000 µM. The fabricated green synthesized CeO2 electrode exhibited a linear behaviour and the detection limit was found to be 0.47 nM exhibited excellent stability. The green synthesized CeO2 can also be used in trace detection of Cd2+ ions in environmental samples. The nanoceria synthesized via orange peel extract has high electrochemical performance would be of great interest for constructing novel sensing platforms for monitoring heavy metal ions (Cd2+) in environment.

Hierarchically porous carbon nanosheets derived from Bougainvillea petals with “pores-on-surface” structure for ultrahigh performance Zinc-ions hybrid capacitors

Due to the outstanding electrochemical performance, high safety coefficient, controllable reaction system and low production cost, Zinc-ion hybrid capacitors (ZIHCs) is considered as a new generation of promising energy storage technology, which even seem as a suitable choice for Medical application. However, to produce ideal carbon-base cathode material with low cost and high electrochemical performance still face challenge. Here, we report a ZIHCs’ cathode based on Bougainvillea petal-derived porous carbon nanosheets (Carbonized Bougainvillea activated at 850 °C, CB-3-850). CB-3-850 derived from Bougainvillea petals exhibit extremely an ultrahigh discharge capacity of 239.1 mAh g−1 at 0.5 A g−1 (from 0 V to 1.8 V) and an excellent electrochemical stability at 20 A g−1 (90 %, 10,000 cycles). In addition, ultrahigh energy density (213.4 Wh kg−1) and high power density (14.8 kW kg−1) are realized in CB-3-850. Special “pores-on-surface” structure and ultrathin nanosheet-like morphology of CB-3-850 not only provide a high specific surface area that for more Zn2+ and SO42+ absorbed on its surface but also enable ions across the one nanosheet directly to reach other carbon-sheets units, which realize a fast kinetic process of ions storage and higher capacity. The excellent performance of the Zinc-ion capacitor can be also attributed to N and O doping that strongly interacted with Zn2+ during the charge/discharge process. Finally, natural Bougainvillea petal just contains simple non-metal elements like C, N and O, exhibit high biocompatibility.

Home-made chemical vapor deposition-based synthesis of binder-free nanostructured magnesium-molybdenum-sulfide electrode materials for supercapacitor application

Molybdenum disulfides (MoS2) is considered as promising electrode materials (E-M) for high electrochemical performance (ECP) of lithium-ion batteries and supercapacitors due to their layered nanostructures. Herein, MoS2, MgS and hetrostructure MgS/MoS2 E-Ms comprising of nano-particles/sheets/needles like structures are synthesized on Nickel foam (Ni–F) by a simple home-made chemical vapor deposition (CVD) technique. The XRD analysis confirmed the formation of MoS2, MgS and MgS/MoS2 polycrystalline E-Ms growing along different directions. The FESEM analysis is confirmed that the addition of MgS layer over the surface of MoS2 change the surafce morphology from nano-particles to nano-needles. The change in structural and microstructural features is indicated the appearance of defects, micro-strain and dislocations density which are fruitful for excellent ECP. The cyclic voltammetry analysis is indicated the pseudocapacitive nature of the synthesized E-Ms. The maximum specific capacitance values for MoS2/Ni–F, MgS/Ni–F and MgS/MoS2/Ni–F E-Ms are 1273, 1688 and 3934 F/g at 1 A/g respectively. Moreover, the addition of MgS layer over MoS2/Ni–F is revealed the excellent cyclic stability of 98.76 % at current density of 10 A/g after 4000 cycles, energy density values are ranged from 79 to 136 W h/kg with homologous power density of 250–2500 W/kg and very small charge transfer resistance. The simulations of Power's Law and Dunn's model is confirmed that the excellent ECP is due to both capacitive and diffusive controlled contributions of heterostructured MgS/MoS2/Ni–F E-Ms. Additionally, MgS/MoS2/Ni–F E-Ms have both battery and pseudocapacitive nature due to unique nano-needles like morphology. The excellent electrochemical properties of MgS/MoS2/Ni–F E-Ms substantiate their potential applications in portable energy storage devices.

Eco-friendly aqueous spinning of robust and porous carbon nanotube/graphene hybrid microelectrodes: The graphene oxide size effect

An eco-friendly, cost-effective, and scalable aqueous spinning of robust and porous hybrid fibers consisting of carbon nanotubes (CNTs) and graphene has been developed. We focus on the design of nanoarchitecture within CNT fibers involving the precise control of CNT bundle size and alignment, porosity, and the interaction between CNTs and Graphene. The effect of graphene oxides (GO) sizes on the quality of CNT/GO aqueous dispersions and the structures/properties of the as-spun fibers was investigated, and nano-sized GO was found to be most effective in reducing CNT bundle size, improving CNT alignment, and strengthening the fibers. After high-temperature treatment, the specific strength and specific conductivity of these CNT/graphene hybrid fibers reached to 1.02 N/tex and 1202.01 S m2/g, which were 7.39 and 1.21 times higher than those of pure CNT fibers. Meanwhile, the CNT/graphene hybrid fibers also have a high specific capacity of 168 F g−1. The combination of high mechanical, electrical, and electrochemical performances makes the CNT/graphene hybrid fibers promising materials for wearable electronics.

S doping induced phase transition of CoMoO4 and decorated on KCu7S4 for high specific capacitance supercapacitor electrode material

Due to the importance of electrode materials for supercapacitors, modified transition metal compounds are better suited to their needs. Compounding and ion doping are two effective modification pathways to optimize the structure of electrode materials and enhance the ion migration kinetics, and thus improve the electrochemical performance of transition metal compounds. In this paper, KCu7S4@S-CoMoO4 (S doping) was prepared by a two-step hydrothermal method. The S doping would cause the phase transition of CoMoO4 and enhance crystallinity. Additionally, the possible substituted oxygen position of S atom was simulated by density functional theory (DFT). Electrochemical characterization showed that the specific capacitance of KCu7S4@S-CoMoO4 prepared under optimal condition was as high as 2866.77 F/g at a current density of 0.5 A/g. The assembled KCu7S4@S-CoMoO4//AC hybrid supercapacitor exhibits the maximum energy density of 132.71 Wh/kg in liquid system condition and the specific capacitance maintained 80.9% of the initial capacitance after 3500 charge/discharge cycles. This work provides ideas for designing materials with high electrochemical performance.

High-performance fibre battery with polymer gel electrolyte.

Replacement of liquid electrolytes with polymer gel electrolytes is recognized as a general and effective way of solving safety problems and achieving high flexibility in wearable batteries1-6. However, the poor interface between polymer gel electrolyte and electrode, caused by insufficient wetting, produces much poorer electrochemical properties, especially during the deformation of the battery7-9. Here we report a strategy for designing channel structures in electrodes to incorporate polymer gel electrolytes and to form intimate and stable interfaces for high-performance wearable batteries. As a demonstration, multiple electrode fibres were rotated together to form aligned channels, whilethe surface of each electrode fibre was designed with networked channels. The monomer solution was effectively infiltrated first along the aligned channels and then into the networked channels. The monomers were then polymerized to produce a gel electrolyte and form intimate and stable interfaces with the electrodes. The resulting fibre lithium-ion battery (FLB) showed high electrochemical performances (for example, an energy density of about 128 Wh kg-1). This strategy also enabled the production of FLBs with a high rate of 3,600 m h-1 per winding unit. The continuous FLBs were woven into a 50 cm × 30 cm textile to provide an output capacity of 2,975 mAh. The FLB textiles worked safely under extreme conditions, such as temperatures of -40 °C and 80 °C and a vacuum of -0.08 MPa. The FLBs show promise for applications in firefighting and space exploration.

High voltage electrochemical performance of single crystal LiNi0.8Co0.1Mn0.1O2 cathode materials with Al-Mg dual doping

Single-crystal materials have high structural stability and low parasitic side reactions for nickel-rich cathodes due to the absence of grain boundaries. However, they suffer challenges such as the complex synthesis route, sluggish lithium-ion diffusion kinetics, and microcracking evolution at high voltage. Bulk co-doping of Al and Mg into the precursors is first employed by a co-precipitation method, and then the Al-Mg dual-doped single-crystal NCM811 cathode is successfully prepared using a straightforward one-step method to reduce production cost. The cycle retention of the corresponding optimized single-crystal material is notably increased by 24.36% compared to the commercial counterpart at 1 C and a high voltage of 4.5 V. Additionally, the discharge capacity at 0.1 C is improved by 4.64% compared to the commercial one with an appropriate annealing temperature and lithium salt ratio. Some advances in the synthesis approach and modification strategy for developing commercial single-crystal material are provided.

Enhancing the specific capacitance of α-MnO2 through quenching-induced changes in the crystal phase structure

The development of materials with high electrochemical performance as response to the energy demand leads to the development of methods for enhancing the specific capacity of energy storage devices, such as heat treatment, which is used to modify the structure and electrochemical performance of materials. This paper reports the enhancement of specific capacitance of α-MnO2 through the high-volume cell (HVC) induced by the quenching technique. Analysis of the transformation and structure of HVC was carried out by a combination of thermal gravimetric analysis and differential scanning calorimetry (TGA–DSC) in addition to X-ray diffraction (XRD), while the characterization of morphology, crystal structure, and capacitance were performed through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and cyclic voltammetry (CV). The α-MnO2 quenched at 437 °C promotes a structural modification that enables an increase in cell volume of 10.6% and an increase in specific capacitance of 20%. The quenching technique would be an attractive methodology to improve the electrochemical performance of materials for energy storage.