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In this study, a novel multiscale carbon architecture was developed by integrating mesocarbon microbeads (MCMBs), graphitic nanofibers (GNFs), and mesoporous carbon, aimed at enhancing the performance of symmetric supercapacitors. The unique combination of spherical MCMB particles, conductive GNF nanofibers, and mesoporous carbon sheets resulted in a highly effective electrode material, offering improved conductivity, increased active sites for charge storage, and enhanced structural stability. The fabricated MCMB/GNF/MC architecture demonstrated a remarkable specific capacitance of 393 F g−1 at 1 A g−1 in a three-electrode system, significantly surpassing the performance of individual MCMBs and MCMB/GNF electrodes. Furthermore, the architecture was incorporated into a symmetric supercapacitor (SSC) device, where it achieved a capacitance of 86 F g−1 at 1 A g−1. The device exhibited excellent cycling stability, retaining 92% of its initial capacitance after 10,000 charge–discharge cycles, with an outstanding coulombic efficiency of 99%. At optimal operating conditions, the SSC device delivered an energy density of 11 Wh kg−1 at a power density of 500 W kg−1, making it a promising candidate for high-performance energy-storage applications. This multiscale carbon architecture represents a significant advancement in the design of electrode materials for symmetric supercapacitors, offering a balance of high energy and power density, long-term stability, and excellent scalability for practical applications. This work not only contributes to the development of high-performance electrode materials but also paves the way for scalable, long-lasting supercapacitors for future energy-storage technologies. [ABSTRACT FROM AUTHOR]

Increasing concerns about the vulnerability of the world’s energy supply and the necessity to implement sustainable technologies have prompted researchers to develop high-performance electrocatalysts that are affordable and efficient for converting and storing renewable energy. This article reports a facile approach to fabricating two-dimensional (2D) Ge-decorated h-BN/MoS2 heterostructure nanosheets by self-assembly for multiple electrochemical applications such as supercapacitor and hydrogen evolution reactions. The organization of the physical and chemical links between the germanium modulations on the heterostructure of boron nitride/molybdenum sulphide (Ge/h-BN/MoS2) were facilitated to generate more active sites. Furthermore, the asymmetric supercapacitor of Ge-decorated h-BN/MoS2 amplified the capacitance to 558.53 F g−1 at 1 A g−1 current density and 159.19 F g−1 at 10 A g−1, in addition to a retention rate of 85.69% after 2000 cycles. Moreover, the Ge-decorated h-BN/MoS2 catalyst realized a low over-potential value, with an RHE of 0.57 (HER) at 5 mA/cm2, a Tafel value of ∼204 mV/dec, and long-term electrolysis stability of 10 h. This work may open the door for further investigations on metal-decorated heterostructures, which have a significant potential for both supercapacitor and water-splitting applications.

This manuscript presents a novel method to enhance the electrochemical performance of CaMoO4 for supercapacitors by synthesizing it from a bi-metallic metal–organic framework (MOF). The resulting CaMoO4 nanoparticles retain MOF characteristics, with a high surface area, and demonstrate improved performance over conventionally synthesized CaMoO4. Electrochemical tests showed the MOF-derived CaMoO4 achieved a high capacitance of 377.82 F g−1 at 1 A g−1 and retained 91% of its capacitance after 5000 cycles. The assembled asymmetric supercapacitor also retained 88% of its capacitance after 10 000 cycles, highlighting the potential of this approach for enhancing energy storage devices. [ABSTRACT FROM AUTHOR]

The development of advanced tin and niobium bimetallic composite electrode materials is crucial for enhancing the performance of supercapacitors. In this paper, we present a novel bimetallic composite material consisting of zero-dimensional spherical-like SnNb2O6 nanocomposites synthesized through the reaction of tin oxide (SnO2) and niobium pentoxide (Nb2O5) precursors, alongside comparative materials. The morphology of the spherical agglomerates comprising Sn/Nb oxide particles that were nucleated on the SnNb2O6 surface was characterized using field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM). The as-prepared heterostructures of the SnNb2O6 composites were analyzed for elemental composition, including Sn3d, Nb3d, and O1s; moreover, chemical oxidative state analysis was performed through X-ray photoelectron spectroscopy (XPS). Additionally, cyclic voltammetry curves exhibited pseudocapacitive redox behavior for the SnNb2O6 composites, while the galvanostatic charge-discharge (GCD) performance demonstrated a maximum specific capacitance of 294.8 F/g at 1 A/g. Moreover, SnNb2O6 composite electrodes demonstrated rapid charge–discharge kinetics and excellent cycling stability, with a capacitance retention of 95.7% over 10,000 cycles. This study elucidated the synthesis of tin–niobium oxide-based composites, demonstrating their potential for high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

This research details the successful synthesis of a CoP/MXene nanomaterial, characterized by unique rod-like structures and MXene layers. In a three-electrode system, the nanomaterial exhibits outstanding electrochemical performance, achieving a specific capacitance of 637 F g-1. When integrated into a supercapacitor device, it demonstrates highly advantageous characteristics, confirming its potential for diverse industrial applications. The device displays confirmed battery-type behavior, coupled with efficient diffusive and capacitive performance, resulting in a specific capacitance of 94.4 F g-1. Notably, the device showcases impressive energy density and power density values, measuring 29.5 W h kg-1 at 750 W kg-1, emphasizing its suitability for robust industrial applications. The rate capability is evident, as illustrated by the sustained distorted rectangular shape in the cyclic voltammetry plots at varying scan rates. [ABSTRACT FROM AUTHOR]

Designing and developing high‐efficiency multifunctional catalysts materials is a significant challenge. In this view, we synthesized Graphene Quantum Dots (gQDs)/Gadolinium Manganese Oxide (GMO) nanostructures for photocatalytic dye degradation and hydrogen peroxide sensing. The structural, optical, composition, and morphology properties of the gQDs/GMO nanostructures were analyzed by using various analytical tools. The gQDs/GMO catalyst shows higher degradation efficiency compared to pure catalysts under visible light irradiation which is due to the large surface area, lower band gap, small amount of hydrogen peroxide (H2O2), and synergetic effect of gQDs/GMO. Furthermore, we extensively investigate the nonenzymatic H2O2 sensing and the gQDs/GMO catalytic materials show higher sensing behavior. From our results, the gQDs embedded in gadolinium‐modified manganese oxide (gQDs/GMO) serve as an efficient photocatalyst material for environmental pollutant degradation under visible light irradiation with and the sensitive electrocatalyst for nonenzymatic H2O2 sensing applications. [ABSTRACT FROM AUTHOR]

A heightened interest in developing MXene (Ti3C2Tx) for energy storage is evident in binder-free MXene ink being directly applied to current collector Ni-foam. Moreover, 2D titanium carbide MXene, with a few layers of nanostructure, has been prepared for symmetric supercapacitor device applications. As-prepared MXene nanosheets exist in two forms: dried powder and ink, achieved through wet-chemical etching and dimethyl sulfoxide delamination from the MAX (Ti3AlC2) phase. This comparative study of electrode devices involves (i) MX-dry powder with binder/additive electrodes and (ii) binder-free MXene inks with directly applied MX-conductive inks. The surface morphological images of pure MX-powder/ink display few layers, and material analysis reveals the good crystalline nature of delaminated MXene (Ti3C2Tx) inks. The electrochemical symmetric supercapacitor device performances of pure MXene powder and binder-free directly applied/coated MXene (Ti3C2Tx) ink, in terms of cyclic voltammetry (CV) and impedance spectroscopy (EIS), exhibit galvanostatic charge–discharge (GCD) curves that show high specific capacitance (Csp) at 105.75 F/g at a current density of 1 A/g. A comparison of active material electrodes demonstrated excellent cycle stability. Hence, in this work, we confirmed the superior capacitive behavior of binder-free MXene ink (MX-I) compared to conductive additives with polymeric binders included in MXene electrodes. [ABSTRACT FROM AUTHOR]

A metal oxide consisting of calcium and manganese (CaMn3O6) in a spherical architecture was successfully prepared by a simple hydrothermal method. Subsequently, Ipomoea carnea-derived carbon (IC) was synthesized and a nanocomposite with CaMn3O6 was formed. The pure CaMn3O6 exhibited a higher surface area of 111 m2 g−1 and CaMn3O6/IC showed a surface area of 101 m2 g−1 with enhanced pore volume, which was desirable in delivering better capacitance. The electrode materials were tested in both three-electrode and two-electrode systems in which CaMn3O6 delivered a capacitance of 294 F g−1 and CaMn3O6/IC delivered a capacitance of 414 F g−1. Furthermore, on fabricating a pouch-cell type asymmetric supercapacitor, CaMn3O6‖AC device showed a capacitance of 76 F g−1 and CaMn3O6/IC‖AC device delivered a capacitance of 116 F g−1. In addition, the CaMn3O6/IC‖AC device showed superior stability and capacitance retention, which can be associated with the presence of an IC matrix. Utilizing the CaMn3O6/IC‖AC pouch-cell device, an LED bulb was operated to test for real-time applications. [ABSTRACT FROM AUTHOR]

Lithium iron orthosilicate (LFS) cathode can be prepared via the polyol-assisted ball milling method with the incorporation of carbon derived from eggshell membrane (ESM) for improving inherent poor electronic conduction. The powder X-ray diffraction (XRD) pattern confirmed the diffraction peaks without any presence of further impure phase. Overall, 9 wt.% of carbon was loaded on the LFS, which was identified using thermogravimetric analysis. The nature of carbon was described using parameters such as monolayer, and average surface area was 53.5 and 24 m2 g−1 with the aid of Langmuir and Brunauer−Emmett−Teller (BET) surface area respectively. The binding energy was observed at 285.66 eV for C−N owing to the nitrogen content in eggshell membrane, which provides more charge carriers for conduction. Transmission electron microscopy (TEM) images clearly show the carbon coating on the LFS, the porous nature of carbon, and the atom arrangements. From the cyclic voltammetry (CV) curve, the ratio of the anodic to the cathodic peak current was calculated as 1.03, which reveals that the materials possess good reversibility. Due to the reversibility of the redox mechanism, the material exhibits discharge specific capacity of 194 mAh g−1 for the first cycle, with capacity retention and an average coulombic efficiency of 94.7% and 98.5% up to 50 cycles.

The great interest in developing emerging zinc-ion capacitors (ZIC) for energy storage applications is due to their inexpensiveness and the future necessity for hybrid electrical energy storage devices. The Zn-ion hybrid capacitor device was assembled using boron (B)-doped reduced graphene oxide (B-RGO) material, which acts as the cathode, and pure zinc metal as an anode. This research work aims to study the influence of B-doped reduced graphene oxide (B-RGO) with Aloe vera gel as an electrolyte. The reduced graphene oxide (RGO) and B-RGO electrode active materials were confirmed through X-ray diffraction (XRD), RAMAN, Fourier transformation infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and field emission-transmission electron microscopy (FE-TEM) analysis. The surface morphological images reveal that a few-layered nanostructure B-RGO was used in the Zn-ion hybrid capacitor device. The electrochemical performance of the Zn-ion hybrid capacitor was evaluated through cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) measurements, with a wide active potential range of 0–2 V versus Zn/Zn+. The mixture composition of Aloe vera extract and 1M ZnSO4 electrolyte generated a stable voltage and exhibited good capacitive behavior. The fabricated ZIC coin cell device with the Aloe vera gel semi-gel electrolyte containing ZnSO4 demonstrated improved Zn+ ionic exchange and storage efficiency. Moreover, the B-RGO electrode active material exhibited excellent cycle stability. The simple one-step electrochemical technique is the most suitable process for boron doping into graphene nanosheets for future energy storage applications. [ABSTRACT FROM AUTHOR]

In this study, noble metal-free Co(OH)F and CoP nanorod electrocatalysts were prepared and explored as bifunctional oxygen electrodes (BOE) in anion exchange membrane-unitized regenerative fuel cells (AEM-URFCs). A CoP nanorod was synthesized from Co(OH)F via the hydrothermal treatment of cobalt nitrate, ammonium fluoride, and urea, followed by phosphorization. The crystal structures, surface morphologies, pore distributions, and elemental statuses of the obtained catalysts were analyzed to identify the changes caused by the incorporation of fluorine and phosphorus. The presence of F and P was confirmed through EDS and XPS analyses, respectively. Using these catalysts, the AEM-based URFCs were operated with hydrogen and oxygen in the fuel cell mode and pure water in the electrolysis mode. In addition, the electrocatalytic activities of the catalysts were evaluated using cyclic voltammetry and electrochemical impedance spectroscopy. In the AEM-URFC test, the CoP catalyst in the BOE delivered the best performance in the fuel cell mode (105 mA cm−2 at 0.3 V), and Co(OH)F was suitable for the water electrolyzer mode (30 mA cm−2 at 2.0 V). CoP and Co(OH)F exhibited higher round trip efficiency (RTE) and power densities than the conventional Co3O4 catalyst. [ABSTRACT FROM AUTHOR]

In order to achieve sustainability goals, biomass is a renewable energy source that lowers emissions of greenhouse gases and other hazardous gases. Biochemical and thermochemical methods are both used to produce bioenergy from biomass. Pyrolysis is an effective thermochemical conversion technique used for the conversion of biomass into energy-rich bio-oil. In this study, the pyrolysis characteristics and bio-oil obtained from the residues of Ricinus communis were investigated. The experimental run was designed to analyze the impact of bed temperature on product yield by varying the process temperature from 350°C to 750°C. In this study, a maximum of 46.5 wt% of bio-oil was produced at 500°C. The maximum conversion was recorded at temperatures ranging from 450°C to 550°C. The bio-oil obtained at maximum yield conditions was analyzed using different analytical techniques. The Fourier transform infrared spectroscopy (FT-IR) and gas chromatography and mass spectroscopy (GC-MS) analyses of the bio-oil revealed that the oil has a significant amount of phenol derivatives, oxygenated chemicals, acids, and esters. The physical properties of the bio-oil showed that it is viscous and has a medium heating value compared with commercial fossil fuel. [ABSTRACT FROM AUTHOR]

Poly(styrene‐co‐methylmethacrylate) P(S‐MMA) composite polymer electrolytes are having massive consideration for solid‐state electrochemical devices. There are numerous tactics implement to improve the ambient temperature ionic conductivity such as the addition of plasticizers, the inclusion of nanosize ceramic fillers and blending with the host polymer, which were carried out in this work. The effect of CeO2 on the P(S‐MMA)‐poly(vinylidene fluoride) (25:75 of 27 wt%)‐LiClO4 (8 wt%)‐ethylene carbonate:propylene carbonate (1:1 of 65 wt%) system prepared via a conventional solution casting technique. The as‐prepared polymer membranes were characterized using XRD, Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis, SEM and AC impedance analyses. The composite polymer blend gel electrolyte system exhibits high ionic conductivity (2.51 × 10−2 S cm−1) with 6 wt% CeO2 nanofiller at ambient temperature. The conductivity enhancement is due to the presence of a rise in the amorphous content; it is in well concurrence with the XRD results. The optimum electrolyte was used to design the LiFePO4/composite gel polymer electrolyte/Li cell couple in a 2032 type coin cell. It possesses a discharge capacity of 151 mA h g−1 at 0.1 C. © 2021 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Zirconium oxide (ZrO2) filler is successfully synthesized with spherical morphology (particle size 170 nm) by co‐precipitation technique earlier. The as‐prepared ZrO2 ‐(bare, 3, 6, 9, and 12 wt%) is spread into the augmented poly(styrene‐co‐ methyl methacrylate) P(S‐MMA)‐ poly vinylidene fluoride (PVdF) (25:75 of 27 wt%)‐LiClO4 (8 wt%)‐ ethylene carbonate and propylene carbonate (EC + PC) (1: 1 of 65 wt%) system. The solution casting technique is employed throughout the process. The structural, morphology, thermal and ionic conducting behavior of sample are examined. The highest conductivity is 1.2 × 10−2 S cm−1 at 303 K for P(S‐MMA)‐PVdF (25:75 of 27 wt%) LiClO4 (8 wt%)‐ EC + PC (65 wt%) +6 wt% ZrO2 system. The linear sweep voltammetry and the cyclic voltammetry tests are performed and the results are discussed. The optimized electrolyte is used to make the LiFePO4/CGPE/Li confined 2032 coin cell couple. It holds the discharge capacity of 144 mAh g−1 at rate of 0.1 C with 88% coulombic efficiency. [ABSTRACT FROM AUTHOR]

Summary: Lithium‐sulfur (Li‐S) batteries are deliberated as capable candidate in next generation of rechargeable batteries. It offers a significant specific capacity of 1675 mAh/g and high‐energy density (2600 Wh/kg). In this work, sulfur/MnO2/graphene oxide (GO) composite has been prepared by incorporating sulfur in different ratios with MnO2 and GO (10:20 and 20:10; SMG1 and SMG2) by solid state reaction and used as cathode for Li‐S battery. The obtained composites have been characterized for physical and electrochemical performances. The XRD spectrum display the sulfur is in orthorhombic structure and the presence of carbon has been confirmed by Raman analysis. The SMG2 composite with 70 wt% of sulfur displays a considerably embellished cycling performance (1610 mAh/g at an initial cycle at 0.1 C). The capacity and stability of the material is achieved by suppressing the polysulfides effectively. Low capacity fade, accommodation of volume change arising during cycling processes makes this positive electrode material competent for Li‐S battery application. [ABSTRACT FROM AUTHOR]

Improving the electrochemical performance of metal oxide-based materials for energy storage devices often involves employing key strategies, including the deliberate modification of composition through composite formation and the application of structural engineering techniques. Herein, we have synthesized bismuth antimonate (BiSbO 4) and ternary structure is constructed by integrating Graphitic Nanofiber (GNF) and MXene (MX) via a facile hydrothermal method. The synergistic effect of the well-defined structure, coupled with the excellent electrical conductivity facilitated by the MXene and GNF networks, significantly contributes to the outstanding energy and power density. The unblocked ion and electron channels within its hierarchical structure enhances the material's performance as a battery-type cathode for supercapacitors. This work reports a notable specific capacitance of 819 F g−1 at 1 A g−1 and an impressive durability, with 94% capacity retention after 5000 charge/discharge cycles in a three-electrode system. Furthermore, an asymmetric supercapacitor device BSO–GF–MX‖AC is fabricated with activated carbon as negative electrode, which delivered superior energy density 46 Wh kg−1 at power density 750 W kg−1 and retains 90.6% of initial capacitance. This study provides a promising strategy for fabricating ternary composite-based electrodes, offering a pathway to assemble high-performance and cost-effective energy storage devices. [Display omitted] • The composite BSO–GF–MX is formed through integration of BiSbO 4 , graphitic nanofiber and MXene. • BSO–GF–MX with micro and mesopores enhances nanocomposite's battery-type performance. • The electrode demonstrates a capacitance of 819 F g−1 at 1 A g−1 in a three-electrode system. • The fabricated device shows energy density of 46.1 Wh kg−1 at power density 750 W kg−1. [ABSTRACT FROM AUTHOR]

NbSnMoS2 material with an enhanced extrinsic nature was synthesized using the hydrothermal method and employed as an electrode for hybrid supercapacitor application (HSC). X-ray diffraction pattern confirmed the hexagonal crystal structure formation in NbSnMoS2 material. A morphology with nanosheets, along with clustered nanoparticles, was identified in NbSnMoS2 using field emission scanning electron microscopy. The presence of Nb4+/5+, Sn4+, Mo4+, S2−, and O2− compositional states in NbSnMoS2 was confirmed through X-ray photoelectron spectroscopy. The electrochemical three-electrode system benefited from the intensified van der Waals interaction and enriched sulfur-edged active sites, therefore, a high specific capacitance of 536.2 F g−1 at 1 A g−1 was gained by the NbSnMoS2 electrode. The facile ion transport pathway was enhanced by the smooth electrode/electrolyte interface formation, whereby the constructed NbSnMoS2//AC HSC device showed energy and power density of 25.04 W h kg−1 and 800 W kg−1. The HSC device retained 99.21 and 93.99% of its coulombic efficiency and capacity retention for 10 000 cycles. The results prove that NbSnMoS2 is a novel material for the development of commercial supercapacitors. [ABSTRACT FROM AUTHOR]

Increasing concerns about the vulnerability of the world's energy supply and the necessity to implement sustainable technologies have prompted researchers to develop high-performance electrocatalysts that are affordable and efficient for converting and storing renewable energy. This article reports a facile approach to fabricating two-dimensional (2D) Ge-decorated h-BN/MoS2 heterostructure nanosheets by self-assembly for multiple electrochemical applications such as supercapacitor and hydrogen evolution reactions. The organization of the physical and chemical links between the germanium modulations on the heterostructure of boron nitride/molybdenum sulphide (Ge/h-BN/MoS2) were facilitated to generate more active sites. Furthermore, the asymmetric supercapacitor of Ge-decorated h-BN/MoS2 amplified the capacitance to 558.53 F g−1 at 1 A g−1 current density and 159.19 F g−1 at 10 A g−1, in addition to a retention rate of 85.69% after 2000 cycles. Moreover, the Ge-decorated h-BN/MoS2 catalyst realized a low over-potential value, with an RHE of 0.57 (HER) at 5 mA/cm2, a Tafel value of ∼204 mV/dec, and long-term electrolysis stability of 10 h. This work may open the door for further investigations on metal-decorated heterostructures, which have a significant potential for both supercapacitor and water-splitting applications. [ABSTRACT FROM AUTHOR]

The pure crystalline cerium oxide (CeO2) nanoparticles were synthesized using optimized content of Ce(NO3)3. 6H2O with varying concentrations of sodium hydroxide (NaOH) (0.5, 1, 1.5, and 2 M) as a precipitation agent in presence of 2.5 wt% poly(vinylpyrrolidone) PVP. All the samples are prepared via the modified coprecipitation technique. The synthesized materials have been analyzed using X‐ray diffraction (XRD), Fourier transform infrared (FT‐IR), laser Raman, high‐resolution scanning electron microscope (HR‐SEM), and photo luminescence (PL) analyses. The optimized sample was identified with the help of the above studies that could be analyzed through transverse electron microscopy (TEM) and X‐ray photoelectron spectroscopy (XPS) studies. The cubic structure with the Fm‐3 m space group has been confirmed through XRD (JCPDS: 81‐0792) and Raman analyses. The FT‐IR and energy dispersive X‐ray spectroscopy (EDX) analyses ascertain the occurrence of Ce and O species. The as‐prepared CeO2 filler (0, 3, 6, 9, and 12 wt%) is dispersed through the optimized polymer electrolyte Poly (styrene‐co‐methyl methacrylate) P(S‐MMA) (27 wt%)–lithium perchloride (LiClO4) (8 wt%)–ethylene carbonate + propylene carbonate (EC + PC) (1;1 of 65 wt%) complex system using solution casting technique. P(S‐MMA) (27 wt%)–LiClO4 (8 wt%)–EC + PC (1;1 of 65 wt%)–6 wt% of CeO2 shows the high ionic conductivity 8.13 × 10−4 S cm−1. [ABSTRACT FROM AUTHOR]

Summary: Layered LiNi0.94Co0.06O2 (LNCO) was prepared and explored as an energy‐storage material for Li‐ion (LIBs), Na‐ion (SIBs) batteries as well as supercapacitor application for the first time. All the physical and morphological characterizations were studied for the sample LNCO. The result displays good thermal stability, phase purity in the crystal structure, appreciable Brunauer‐Emmett‐Teller (BET) surface area (5.53 m2 g−1) and possesses cubic morphology. The cobalt was identified in lithium nickel oxide with binding energies at 794.02, 779.04 and 784.30 eV, respectively. In the case of LIBs, LNCO exists with a minimal difference of 5 mAh g−1, even when cycled from 2C to 0.1C. After 200 cycles, the specific capacity, 247 mAh g−1, is obtained for the cell with retention of 97.8% (efficiency 99.8%) at 0.1C. In SIBs, at 0.1C, the discharge capacity of 182 mAh g−1 was restored even when cycled after 2C. After 200 cycles, a discharge capacity of 204 mAh g−1 is ensured with retention of 96.6% (efficiency of 99.4% at 0.1C). In supercapacitor, the electrode, LNCO, delivered a specific capacity of 300 F g−1 at 0.5 A g−1. Therefore, LNCO is highly recommended as a suitable electrode material for fulfilling the requirement of energy‐storage applications. [ABSTRACT FROM AUTHOR]

Sulfur (S)/silicon dioxide (SiO2)/multiwalled carbon nanotube (MWCNT) ternary composites with potential application in high-performance lithium-sulfur (Li-S) batteries have been prepared by a heat treatment method. The S/SiO2/MWCNT composite with MWCNT content of 20 wt.% exhibited efficient electrochemical performance for use as a cathode in Li-S batteries, with initial discharge capacity of 926 mAh g−1 and coulombic efficiency of 99% at 0.2 C rate. A discharge capacity of 501 mAh g−1 was observed after 300 cycles with a decay rate of 0.15% per cycle. The average capacity retention was found to be 81.7% and 54.1% after 100 cycles and 300 cycles, respectively. These results demonstrate that a high content of MWCNT improved the electronic conductivity while the SiO2/MWCNT matrix represents a strong physical and chemical host for the polysulfides and active material. This study determines the combined effect of silica and MWCNT to improve the performance of the sulfur cathode. [ABSTRACT FROM AUTHOR]

Lithium iron orthosilicate (LFS) cathode can be prepared via the polyol-assisted ball milling method with the incorporation of carbon derived from eggshell membrane (ESM) for improving inherent poor electronic conduction. The powder X-ray diffraction (XRD) pattern confirmed the diffraction peaks without any presence of further impure phase. Overall, 9 wt.% of carbon was loaded on the LFS, which was identified using thermogravimetric analysis. The nature of carbon was described using parameters such as monolayer, and average surface area was 53.5 and 24 m2 g−1 with the aid of Langmuir and Brunauer–Emmett–Teller (BET) surface area respectively. The binding energy was observed at 285.66 eV for C–N owing to the nitrogen content in eggshell membrane, which provides more charge carriers for conduction. Transmission electron microscopy (TEM) images clearly show the carbon coating on the LFS, the porous nature of carbon, and the atom arrangements. From the cyclic voltammetry (CV) curve, the ratio of the anodic to the cathodic peak current was calculated as 1.03, which reveals that the materials possess good reversibility. Due to the reversibility of the redox mechanism, the material exhibits discharge specific capacity of 194 mAh g−1 for the first cycle, with capacity retention and an average coulombic efficiency of 94.7% and 98.5% up to 50 cycles. [ABSTRACT FROM AUTHOR]

In the present study, Li2FeSiO4 (LFS) cathode material has been prepared via a modified polyol method. The stabilizing nature of polyol solvent was greatly influenced to reduce the particle size (~50 nm) and for coating the carbon on the surface of the as-mentioned materials (~10 nm). As-prepared nano-sized Li2FeSiO4 material deliver initial discharge capacity of 186 mAh·g−1 at 1C with the coulombic efficiency of 99% and sustain up to 100 cycles with only 7 mAh·g−1 is the difference of discharge capacity from its 1st cycle to 100th cycle. The rate performance illustrates the discharge capacity 280 mAh·g−1 for lower C-rate (C/20) and 95 mAh·g−1 for higher C-rate (2C). [ABSTRACT FROM AUTHOR]