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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.

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]

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]

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]