High Capacity Performance Research Articles

Metal-decorated M-graphene for high hydrogen storage capability and reversible hydrogen release

With the increasing demand for green energy, the design of effective hydrogen storage materials is becoming particularly important. In this work, the hydrogen storage performances of the metal atoms (Li, Ca, and Sc) decorated two–dimensional (2D) M-graphenes were investigated with density functional theory (DFT) calculations. The metal atoms can be substantially anchored on the M-graphene surface in single–atom formation revealed by the high binding energy, which is ascribed to the remarkable charge transfers between metal atom and M-graphene. Each metal atom can capture six H2 molecules at most in single–atom decorated M-graphene. The H2 adsorption energies are in the range from −0.139 to −0.375 eV, following an order of Sc@M-graphene > Ca@M-graphene > Li@M-graphene. The affinity ability of metal–decorated M-graphene for hydrogen can be enhanced by adding an external electric field. The multi–metal atoms decorated M-graphenes, Li4C16(H2)8, Ca4C16(H2)12, and Sc4C16(H2)12 complexes show high gravimetric densities (6.06 ∼ 6.78 wt%) and a favorable binding energy window (−0.167 to −0.418 eV), meeting the department of energy (DOE)’s criteria. The thermodynamic properties were in detail studied by considering temperature and pressure effects. AIMD simulations at different temperatures indicate that the efficient release of hydrogen can occur at room temperature. Our results show that the M-graphenes with Li, Ca, and Sc decorated have high hydrogen storage capacity and reversible hydrogen release performance. This work may be useful for designing novel 2D carbon–based materials for hydrogen storage.

Versatile Activated Carbon Fibers Derived from the Cotton Fibers Used as CO2 Solid-State Adsorbents and Electrode Materials.

Activated carbon has an excellent porous structure and is considered a promising adsorbent and electrode material. In this study, activated carbon fibers (ACFs) with abundant microporous structures, derived from natural cotton fibers, were successfully synthesized at a certain temperature in an Ar atmosphere and then activated with KOH. The obtained ACFs were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), elemental analysis, nitrogen and carbon dioxide adsorption-desorption analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption measurement. The obtained ACFs showed high porous qualities and had a surface area from 673 to 1597 m2/g and a pore volume from 0.33 to 0.79 cm3/g. The CO2 capture capacities of prepared ACFs were measured and the maximum capture capacity for CO2 up to 6.9 mmol/g or 4.6 mmol/g could be achieved at 0 °C or 25 °C and 1 standard atmospheric pressure (1 atm). Furthermore, the electrochemical capacitive properties of as-prepared ACFs in KOH aqueous electrolyte were also studied. It is important to note that the pore volume of the pores below 0.90 nm plays key roles to determine both the CO2 capture ability and the electrochemical capacitance. This study provides guidance for designing porous carbon materials with high CO2 capture capacity or excellent capacitance performance.

3D printing of porous hollow nanosphere MoS2@NiS/rGO scaffolds empowering long-cycle sodium-ion batteries

Sodium-ion batteries (SIB), as one of the most appealing electrochemical energy storage devices in the field of energy storage, consistently require optimization for both capacity and long-term cycling performance. The amalgamation of diverse material modification techniques with up-and-coming 3D printing technology presents a promising yet relatively underexplored avenue. Herein, we report a composite material, MoS2@NiS/rGO, as the anode material for SIB, achieving high reversible capacity and outstanding long-term cycling performance, surpassing current reported levels. Through carefully designed anode electrode structure and component interface engineering, the material rate capability (with a capacity of 289.5 mAh g−1 at 0.1 A g−1 and 66.8 mAh g−1 at 5 A g−1) and cycling stability (maintaining a capacity of 131.3 mAh g−1 after 800 cycles at 1 A g−1) are significantly enhanced. The reasons for the improvement in electrochemical performance are elucidated through detailed electrochemical analysis. Encouragingly, we showcase the fabrication of a sodium-ion full battery entirely through 3D printing (3DP), achieving an area loading capacity as high as 8.23 mg cm−2 and retaining a capacity of 82.1 mAh g−1 after 240 cycles at 0.1 A g−1. This work underscores the pivotal significance of 3D-printed sodium-ion batteries in advancing the frontier of energy storage technology.

One-step and universal fabrication of MXene/metal sodiophilic frameworks via Lewis acidic etching toward dendrite-free sodium metal anodes

Although MXene-based 3D scaffolds have boosted the cyclability of Na metal, the complex and harsh synthetic process deteriorates their practical application. Herein, a series of MXene/metal sodiophilic frameworks are constructed through one-step Lewis acidic etching, and metal nanoparticles are uniformly distributed on the surface or intercalated into the large interlayer gaps of MXenes. Notably, MXenes with superior Na+/electron transport kinetics and mechanical flexibility remarkably reduce the local current density, homogenize Na+ flux and cushion huge volume change of Na metal. Moreover, sodiophilic species including MXenes and metals effectively induce Na uniform nucleation and smooth deposition among the 3D matrixes, leading to dendrite-free morphology. Consequently, MXene/metal hosts exhibit stable Na plating/stripping process for 900 cycles with high average Coulombic efficiencies of 99.9% (2 mA cm−2, 1 mAh cm−2). The MXene/metal-Na symmetric cells achieve low overpotentials of less than 15 mV and stable cycling for 2200 h (2 mA cm−2, 4 mAh cm−2). When paired with Na3V2(PO4)3 cathode, the full cells with a low N/P ratio (around 2) demonstrate high discharge capacity and excellent long-term cyclic performance over 600 cycles. The presented universal, safe and one-step approach in fabricating MXene/metal scaffolds shows bright prospects and may promote the development of alkali metal-based batteries.

Aluminum vacancy‐rich MOF‐derived carbon nanosheets for high‐capacity and long‐life aqueous aluminum‐ion battery

AbstractEco‐friendly and safe aqueous aluminum‐ion batteries as energy storage devices with low economic burden, high stability and fast ion transport have been lucubrated deeply in response to the call for sustainable development. However, the poor cycle performance caused by difficult (de‐)intercalation hinders the development prospect. In this work, the aluminum vacancy‐rich MOF‐derived carbon is constructed to achieve reversible aluminum storage during the charge‐discharge cycles. The MOF‐derived carbon with anti‐stacking waxberry‐like structure exhibits high capacity (282.1 mAh g−1 at 50 mA g−1) and long cycle performance (84.4% capacity retention rate at 1 A g−1 after 5000 cycles). Further investigations demonstrate that (de‐)intercalation occurs among the vacancies of carbon nanosheets in the form of hydrated aluminum ions. Meanwhile, the introduced nitrogen as energy storage sites contributes part of the capacity. The proposed aluminum vacancy engineering improves the current situation of the capacitive energy storage mode for 2D carbon materials, which may exploit an advanced theoretical model for the design of aqueous batteries.

Efficient decaffeination with recyclable magnetic microporous carbon from renewable sources: Kinetics and isotherm analysis

Rapid global urbanization and population growth have ignited an alarming surge in emerging contaminants in water bodies, posing health risks, even at trace concentrations. To address this challenge, novel water treatment and reuse technologies are required as current treatment systems are associated with high costs and energy requirements. These drawbacks provide additional incentives for the application of cost-effective and sustainable biomass-derived activated carbon, which possesses high surface area and low toxicity. Herein, we synthesized microporous activated carbon (MAC) and its magnetic derivative (m-MAC) from tannic acid to decaffeinate contaminated aqueous solutions. Detailed characterization using SEM, BET, and PXRD revealed a very high surface area (>1800 m2/g) and a highly porous, amorphous, heterogeneous sponge-like structure. Physicochemical and thermal analyses using XPS, TGA, and EDS confirmed thermal stability, unique surface moieties, and homogeneous elemental distribution. High absorption performance (>96 %) and adsorption capacity (287 and 394 mg/g) were recorded for m-MAC and MAC, respectively. Mechanistic studies showed that the sorption of caffeine is in tandem with multilayer and chemisorptive mechanisms, considering the models’ correlation and error coefficients. π-π stacking and hydrogen bonding were among the interactions that could facilitate MAC-Caffeine and m-MAC-Caffeine bonding interactions. Regeneration and reusability experiments revealed adsorption efficiency ranging from 90.5 to 98.4 % for MAC and 88.6–93.7 % for m-MAC for five cycles. Our findings suggest that MAC and its magnetic derivative are effective for caffeine removal, and potentially other organic contaminants with the possibility of developing commercially viable and cost-effective water polishing tools.

Tailoring Stress-Relieved Structure for SnSe Toward High Performance Potassium Ion Batteries.

Metal chalcogenides as an ideal family of anode materials demonstrate a high theoretical specific capacity for potassium ion batteries (PIBs), but the huge volume variance and poor cyclic stability hinder their practical applications. In this study, a design of a stress self-adaptive structure with ultrafine SnSe nanoparticles embedded in carbon nanofiber (SnSe@CNF) via the electrospinning technology is presented. Such an architecture delivers a record high specific capacity (272 mAh g-1 at 50mA g-1) and high-rate performance (125 mAh g-1 at 1 A g-1) as a PIB anode. It is decoded that the fundamental understanding for this great performance is that the ultrafine SnSe particles enhance the full utilization of the active material and achieve stress relief as the stored strain energy from cycling is insufficient to drive crack propagation and thus alleviates the intrinsic chemo-mechanical degradation of metal chalcogenides.

Modulating zero charge potential of Zn-doped N, P-containing carbon electrodes for efficient copper ion electrosorption

Nitrogen/phosphorus (N/P) doped carbon materials exhibit enhanced electro adsorption capability in capacitive deionization (CDI) applications. However, the incorporation of N/P atoms may introduce electron-withdrawing groups to the electrode surface, impacting the potential of zero charge (EPZC) and thereby influencing its electro adsorption efficiency. This research explores the modulation of electrode surface charge by varying the N/P doping composition. Specifically, it presents a Zn and N/P co-doped carbon material employed as the CDI cathode, showcasing selective adsorption of Cu2+ ions. Under a voltage of 1.2 V, the adsorption capacity achieves 250 mg/g in a 500 mg/L Cu2+ ion solution. Furthermore, it demonstrates outstanding cycling stability, maintaining an adsorption capacity of 233 mg/g even after 21 cycles. This investigation introduces an innovative approach for EPZC adjustment and offers a fresh theoretical framework for fabricating high-performance CDI electrodes.

Oxygen-vacancy-rich Ru nanoclusters doped NiCo metal-organic framework for driving overall water electrolysis and supercapacitors

Due to the growing demand for clean renewable hydrogen fuel, the rational design of electrode materials' composition and structure holds significant importance in achieving efficient energy storage and conversion in electrochemical energy devices. In this study, we synthesize NiCo-MOF74/NF substrate using a one-step hydrothermal method, after which we successfully deposit a layer of Ru metal nanoclusters on the substrate by electrodeposition. Ru NCs@NiCo-MOF74/NF exhibits an exceptionally large specific surface area and excellent interface effects, demonstrating outstanding performance in both overall water splitting and supercapacitor applications. In a 1 M KOH alkaline solution, the device requires only 1.47 V output voltage to deliver a current density of 10 mA cm−2 for overall water splitting. As a supercapacitor, the unique nanoflower structure of Ru NCs@NiCo-MOF74/NF enables fast and reversible Faradaic reactions, providing high specific capacitance and rate performance. It shows a high areal capacitance of 1.664 mAh cm−2 at 1 mA cm−2, indicating excellent charge storage capacity. Assembled into an asymmetric supercapacitor (ASC) with Ru NCs@NiCo-MOF74/NF as the positive electrode, the device achieves a high energy density of 511.88 μWh cm−2 at a power density of 545.68 μW cm−2. After 5000 cycles, the capacitance retention rate is approximately 100 %, demonstrating remarkable cycling stability. This paves the way for the synthesis of multifunctional catalysts, opening up new possibilities in the field.

Stepwise Construction of MoS2@CoAl-LDH/NF 3D Core-Shell Nanoarrays with High Hole Mobility for High-Performance Asymmetric Supercapacitors.

Supercapacitors (SCs) have received widespread attention as excellent energy storage devices, and the design of multicomponent electrode materials and the construction of ingenious structures are the keys to enhancing the performance of SCs. In this paper, MoS2 nanorods were used as the carrier structure to induce the anchoring of CoAl-LDH nanosheets and grow on the surface of nickel foam (NF) in situ, thus obtaining a uniformly distributed MoS2 nanorod@CoAl-LDH nanosheet core-shell nanoarray material (MoS2@CoAl-LDH/NF). On the one hand, the nanorod-structured MoS2 as the core provides high conductivity and support, accelerates electron transfer, and avoids agglomeration of CoAl-LDH nanosheets. On the other hand, CoAl-LDH nanosheet arrays have abundant interfacially active sites, which accelerate the electrolyte penetration and enhance the electrochemical activity. The synergistic effect of the two components and the unique core-shell nanostructure give MoS2@CoAl-LDH/NF a high capacity (14,888.8 mF cm-2 at 2 mA cm-2) and long-term cycling performance (104.4% retention after 5000 charge/discharge cycles). The integrated MoS2@CoAl-LDH/NF//AC device boasts a voltage range spanning from 0 to 1.5 V, achieving a peak energy density of 0.19 mW h cm-2 at 1.5 mW cm-2. Impressively, it maintains a capacitance retention rate of 84.6% after enduring 10,000 cycles, demonstrating exceptional durability and stability.

Electrical and Dielectric Properties of Polymer-Metal Hybrid Nanocomposites - A Short Review

Polymer-metal hybrid nanocomposites have garnered significant attention in recent years due to their exceptional electrical and dielectric properties, which find applications in a wide range of industries, including electronics, energy storage, and advanced materials. This review article provides a comprehensive overview of the current state-of-the-art in the field of polymer-metal hybrid nanocomposites, with a particular focus on their electrical and dielectric properties. The first section of the review delves into the synthesis and fabrication techniques employed to create these nanocomposites, highlighting the importance of controlling the dispersion and distribution of metal nanoparticles within the polymer matrix. Various approaches, such as in-situ polymerization, melt mixing, and electrospinning, are discussed in detail, along with their respective advantages and limitations.The subsequent sections explore the influence of metal nanoparticles on the electrical conductivity and dielectric constant of the nanocomposites. The role of factors such as nanoparticle size, shape, and concentration in determining these properties is thoroughly examined. Moreover, the impact of metal surface modifications and the choice of polymer matrix on enhancing electrical and dielectric performance are also addressed. In addition to discussing fundamental aspects, this review highlights practical applications of polymer-metal hybrid nanocomposites in the development of high-performance capacitors, sensors, electromagnetic shielding materials, and flexible electronics. The potential for these materials to revolutionize various technological sectors is discussed, emphasizing their role in advancing miniaturization, energy efficiency, and durability. Furthermore, the review outlines current challenges and future prospects in the field, including the need for a deeper understanding of the underlying mechanisms governing electrical and dielectric behavior in these nanocomposites. Emerging trends such as the incorporation of 2D materials and the development of multifunctional hybrid systems are also explored, hinting at exciting avenues for further research and innovation. In conclusion, polymer-metal hybrid nanocomposites offer a promising platform for tailoring electrical and dielectric properties to meet the demands of modern technology. This review serves as a valuable resource for researchers, engineers, and scientists seeking to explore the potential of these materials and drive advancements in the field of electrical and dielectric engineering.

Structural insight and modulating of sulfide-based solid-state electrolyte for high-performance solid-state sodium sulfur batteries

Room-temperature (RT) solid-state sodium-sulfur batteries (SSNSBs) are one of the most promising next-generation energy storage systems because of their high energy density, enhanced safety, cost-efficiency, and non-toxicity. While most of the studies for SSNSBs focused on designing and developing sulfur cathodes, we carve out a new path to understanding and modulating the structures and properties of sulfide solid-state electrolytes (SSEs) for achieving high-performance SSNSBs. A novel cation and anion co-doped approach was developed to enhance the ionic conductivity and expand the electrochemical stability of sulfide SSEs, and eventually improve the electrochemical performance of SSNSBs. The crystal structure and local structure of the cation/anion co-doped sulfide SSEs have been studied in detail combined with the density functional theory (DFT) calculations for mechanism understanding. SSNSBs incorporating co-doped sulfide SSEs demonstrate high capacity and stable cycling performance, even at high rates, which is at the top of the reported performances in the literature. Our novel approach for cation and anion-tuned SSEs demonstrates excellent ionic conductivity and electrochemical stability, paving a new way for the next generation of solid-state sodium batteries.

Precision integration of uniform molecular‐level carbon into porous silica framework for synergistic electrochemical activation in high‐performance lithium–ion batteries

AbstractThe development of advanced anode materials for lithium‐ion batteries that can provide high specific capacity and stable cycle performance is of paramount importance. This study presents a novel approach for synthesizing molecular‐level homogeneous carbon integration to porous SiO2 nanoparticles (SiO2@C NPs) tailored to enhance their electrochemical activities for lithium‐ion battery anode. By varying the ratio of the precursors for sol–gel reaction of (phenyltrimethoxysilane (PTMS) and tetraethoxysilane (TEOS)), the carbon content and porosity within SiO2@C NPs is precisely controlled. With a 4:6 PTMS and TEOS ratio, the SiO2@C NPs exhibit a highly mesoporous structure with thin carbon and the partially reduced SiOx phases, which balances ion and charge transfer for electrochemical activation of SiO2@C NPs resulting remarkable capacity and cycle performance. This study offers a novel strategy for preparing affordable high capacity SiO2‐based advanced anode materials with enhanced electrochemical performances.image

Evaluation of Joint Technique Iterative Clipping Filtering (ICF) and Neural Network Predistortion on SDR-based MIMO-OFDM System

Multiple-input, multiple-output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) is a communications technology that powers numerous modern communication systems, including 5G and WiFi-6. This technology is utilized in current communication systems due to its high performance and extensive channel capacity. MIMO-OFDM does have disadvantages, such as large Peak-to-Average Power Ratio (PAPR) values. If the signal is processed by a nonlinear Power Amplifier (PA) device, a high PAPR value signal can result in both in-band and out-of-band signal distortion. To combat high PAPR values, PAPR reduction strategies such as Iterative Clipping Filtering (ICF) are utilized. From this study, using ICF with iteration 2 and Clipping Ratios (CR) 3 and 4 can improve the system's minimum Bit Error Rate (BER) by about 22.8% and 91.1%, respectively. Choosing the correct CR will improve the system, but using the lower CR will make it worse than a system without ICF. This occurs in systems using ICF with iterations two and CR 2 and at the same SNR conditions as systems without ICF; using ICF with iterations two and CR 2 results in higher BER values. The use of Predistortion Neural Network (PDNN) can overcome this problem. By using PDNN, there is an improvement in the system where the minimum BER value can reach 0.1 × 10-5. The percentage decrease in BER from using PDNN for ICF with iterations two and CR 2, 3, and 4 is 99.88%, 99.86%, and 98.807%, respectively. Thus, the joint techniques of ICF and PDNN can significantly enhance the performance of MIMO-OFDM systems with nonlinear PA. Importantly, the experiment was conducted on an SDR device, ensuring the real-world applicability of the results.

Converting “sliding” to “rolling” design for high-performance lubricating hydrogel

Despite the excellent lubricity of conventional hydrogel materials due to their wet-soft properties, they produce severe mechanical elastic deformation at higher interfacial contact stresses. Balancing the load-bearing capacity and lubricating properties of hydrogel material is the difficulty of the current research work for articular cartilage substitutes. Great progress has been made in developing bionic joint materials with high load-bearing and low-friction hydrogels based on gradient designs. However, most bionic materials are based on sliding friction greatly limiting the improvement of lubrication performance. Herein, we designed and prepared a new hydrogel material with high load-bearing capacity and stable lubrication performance, breaking through the traditional friction method and turning to “sliding” for “rolling”. The network on the hydrogel surface was dissociated by UV irradiation and the pores on the surface were filled with SiO2 nanoparticles. The dense network structure of the underlying layer endows the hydrogel material with good load-bearing properties, while the high degree of hydration of the surface layer and the rolling friction effect of SiO2 nanoparticles greatly enhance the lubrication property. With the synergistic effect of these designs, the multi-layered hydrogel with nanoparticles on the surface achieved an ultra-low average coefficient of friction (COF) of ∼0.00809 at a high load of 50 N during 30,000 cycles. This idea of hydrogel material design provides a new strategy for the replacement of biomimetic articular cartilage materials.

Dual-Site Doping in Transition Metal Oxide Cathode Enables High-Voltage Stability of Na-Ion Batteries.

Designing cathode materials that effectively enhancing structural stability under high voltage is paramount for rationally enhancing energy density and safety of Na-ion batteries. This study introduces a novel P2-Na0.73K0.03Ni0.23Li0.1Mn0.67O2 (KLi-NaNMO) cathode through dual-site synergistic doping of K and Li in Na and transition metal (TM) layers. Combining theoretical and experimental studies, this study discovers that Li doping significantly strengthens the orbital overlap of Ni (3d) and O (2p) near the Fermi level, thereby regulates the phase transition and charge compensation processes with synchronized Ni and O redox. The introduction of K further adjusts the ratio of Nae and Naf sites at Na layer with enhanced structural stability and extended lattice space distance, enabling the suppression of TM dissolution, achieving a single-phase transition reaction even at a high voltage of 4.4V, and improving reaction kinetics. Consequently, KLi-NaNMO exhibits a high capacity (105 and 120 mAh g-1 in the voltage of 2-4.2V and 2-4.4V at 0.1 C, respectively) and outstanding cycling performance over 300 cycles under 4.2 and 4.4V. This work provides a dual-site doping strategy to employ synchronized TM and O redox with improved capacity and high structural stability via electronic and crystal structure modulation.

Deep learning prediction and experimental investigation of specific capacitance of nitrogen-doped porous biochar

N-doped porous biochar is a promising carbon material for supercapacitor electrodes due to its developed pore structure and high chemical activity which greatly affect the capacitive performance. Predicting the capacitance and exploring the most influential factors are of great significance because it can not only avoid the trial-and-error experiments but also provide guidance for the synthesis of biochar with the aim of capacitance enhancement. In this study, a CNN model with ReLU activation function was established using DenseNet architecture for specific capacitance prediction. The importance and impacts of the physiochemical properties of N-doped porous biochar to the capacitance were revealed. With the guidance of the model, N-doped porous biochar samples with high capacitance were synthesized, the data of which were further used for model validation. This study provides not only a deep learning model which can be used in practice for capacitance prediction but also directions for the synthesis of N-doped porous biochar with high capacitive performance.

The role of cathode architecture and anion interactions on the performance of Al-substituted α-Ni(OH)2 in rechargeable Ni–Zn cells

Rechargeable alkaline Ni–Zn batteries configured with Zn sponge anodes provide an energy dense, safe alternative to Li-ion batteries for a wide range of risk-averse applications. Advanced cathodes that provide high rate and capacity performance are needed to match that of Zn sponge anodes. We show that aluminum-substituted nickel hydroxide, α-Ni0.9Al0.1(OH)2, expressed in a nanosheet morphology, can be directly deposited onto a flexible carbon nanofiber paper (CNP) using a rapid and scalable two-step microwave-assisted hydrothermal reaction. The architected electrode (α-Ni0.9Al0.1(OH)2@CNP) wires the energy-storing Ni to the carbon scaffold, resulting in high capacity and stable cycling in Ni–Zn cells, performance not obtained using conventional powder-composite cathodes. The growth reaction time and temperature influence mass loading, thickness, crystal structure, the ratio of interlayer ‘free’-to-lattice metal-coordinated ‘bound’ nitrates, and electrochemical performance. The architected α-Ni0.9Al0.1(OH)2@CNP||Zn sponge alkaline cell provides unprecedented performance, delivering high discharge capacity, storage of >1.4 electrons per Ni, good rate capability, excellent capacity retention, and high mass loading. Architected electrodes that combine 3D electronic wiring and structured active material provide a pathway to energy dense, safe, rechargeable Ni–Zn batteries and offer approaches to improve the electrochemical performance of a broad class of layered materials for multiple battery chemistries.

Bi2S3 Confined by Covalent Organic Frameworks Enables High‐Rate High‐Capacity Potassium Storage

AbstractPotassium‐ion hybrid capacitors (PIHCs) are highly promising as an energy‐storage system. However, the rate performance and cycling performance of most materials with high capacity cannot simultaneously meet the requirements of PIHCs. In this work, a composite material of Bi2S3 nanoparticles in situ confined within a sulfur‐doped covalent organic framework (COF) and combined with graphene (Bi2S3@SCOF/G) is synthesized. Due to the synergistic effect of the stability of COF to buffer large mechanical stresses and the high electronic conductivity of graphene, the Bi2S3@SCOF/G anode reveals a high reversible capacity (503.8 mAh g−1 at 100 mA g−1 after 100 cycles) and favorable rate performance (223.9 mAh g−1 even at 5000 mA g−1). Furthermore, the PIHCs assembled with activated carbon show excellent energy density and cycling performance, indicating their potential for practical applications.

Synthesis and characterization of C@CdS core-shell structures for high-performance capacitors

The present study investigates the synthesis and characterization of carbon@cadium sulphide (C@CdS) core-shell nanostructures for their potential application in electrochemical double-layer (ECDL) capacitors. Two distinct synthesis methods, hydrothermal route and co-precipitation method, were employed to fabricate C@CdS materials, each resulting in unique morphology and growth mechanisms. Detailed microstructural analyses, including high-resolution transmission electron microscopy (HR-TEM) and X-ray diffraction (XRD), revealed nanosheets in co-precipitated sample (CCSP) and core-shell structures in hydrothermally synthesized sample (CCSA). Optical investigations using UV-Vis spectroscopy provided insights into the absorbance properties of the synthesized materials. Electrical characterization, including frequency response testing and impedance analysis, demonstrated distinct capacitive behaviours for CCSP and CCSA, highlighting their potential for use in energy storage applications. Electrical characterization, including frequency response testing, impedance analysis, and galvanostatic charge-discharge (GCD) curve analysis, demonstrated distinct capacitive behaviours for CCSP and CCSA, highlighting their potential for use in energy storage applications. The integration of optical, structural, and electrical analyses provides a comprehensive understanding of the synthesized C@CdS core-shell nanostructures, offering insights into their potential application for ECDL capacitor technology and other emerging energy storage applications. Further optimization of synthesis parameters and exploration of scalable production methods are suggested for future research endeavors.