Specific Capacity Research Articles

Hierarchical nanostructured Co0.5Mn0.5WO4 efficient electrode material for asymmetric supercapacitor application

BackgroundThis research focuses on the electrochemical characteristics of binary metal tungstates for asymmetric supercapacitor applications. Metal tungstates such as Cobalt tungstate (CoWO4) and Manganese tungstate (MnWO4) exhibit excellent electrical conductivity and redox characteristics. Different combinations of binary metal tungstates can serve as effective electrode materials for supercapacitor applications. MethodHerein, Co0.5Mn0.5WO4 nanoparticles was synthesized by the co-precipitation method followed by calcination. The prepared nanoparticles was used as an electrode material for the supercapacitor application. For study the two electrode system, Co0.5Mn0.5WO4 and activated carbon were worked as anode and cathode electrode, respectively. Significant findingsThe prepared electrode materials exhibit a battery type pusudocapacitance in cyclic voltammetry (CV). The charging and discharging properties of the material was analysed by galvanic charging and discharging (GCD) studies and it displays the specific capacitance value of 444 F/g at the current density of 1 A/g and it shows the specific capacitance retention of 91% after 1500 cycles. AC//Co0.5Mn0.5WO4 ASC device shows good energy density, power density and specific capacitance values of 30.5 Wh/Kg, 2800 W/Kg and 112 F/g at 1 A/g current density, respectively.

Unlocking the potential of a chemically modified blue phosphorene as anode materials for high-performance sodium-ion batteries

Blue phosphorene (Blu-Pn) has recently been identified as a new two-dimensional (2D) form of black phosphorus via the epitaxial growth method and has shown the ability to host a substantial amount of Na while serving as an anode in sodium-ion batteries (NIBs). However, its structural instability is an issue that hinders its further exploitability in NIBs. In this paper, we propose to chemically modify the Blu-Pn network by substituting six phosphorus atoms with a carbon source in the form of a C6 ring, constructing a new and robust CP2 nanosheet. Based on the state-of-the-art non-local van der Waals corrected density functional theory and ab initio molecular dynamic (AIMD) simulations, we systematically explore the feasibility of the designed CP2 as a potential anode material for NIBs. Adding a C6 ring in the Blu-Pn lattice reduces its energy gap from 2 eV to 1.3 eV, which disappears after Na adsorption, indicating a conductive character. Attributed to the synergistic effect, the adsorption energy of Na on CP2 nanosheet (−2.22 eV) is greatly decreased in comparison to the pristine carbon source (e.g., graphene with −0.78 eV) and pristine Blu-Pn (−1.85 eV). The Na diffusivity on CP2 at 300 K is predicted to be 4.90 × 10−11 m2/s by AIMD. The specific capacity is up to 604.1 mAh/g, which exceeds that of the commercialized graphite anode (372 mA h/g). Ultimately, the designed electrode provides a small open circuit potential of 0.66 V that falls within a desirable voltage range. This work paves the way for exploring Blu-Pn 2D anode materials for NIBs technology and provides valuable insights into surface chemical modification towards the long-term stability of Blu-Pn.

Oxalate and adipate mediated fabrication of CuO nanocrystallites for their electrochemical and supercapacitance studies

Cupric oxide (CuO) has been comprehensively studied in the field of electrochemistry due to its high Tc-Superconducting property. The present work focus on two different CuO materials i.e. CuO-1 and CuO-2 nanocrystallites which are successfully synthesized from their oxalate and adipate precursors respectively. The calcination temperature for the synthesis of CuO from their precursors is ascertained by TGA analysis of the dicarboxylates. Both the CuO materials are thoroughly characterized by SEM–EDS, XRD, IR and XPS spectroscopic techniques. As a candidate for supercapacitor electrode material, CuO-1/C and CuO-2/C showed a specific capacitance of 4.15 F/g and 22.24 F/g using cyclic voltammetry, 10.4 F/g and 46.6 F/g using GCD curves respectively at a current density of 1 A/g. Also, the CuO-1/C and CuO-2/C showed a specific energy density (Es) 1.59 Wh kg−1 and 0.36 Wh kg−1 at a specific power density (Ps) of 0.02 kW kg−1 and 0.025 kW kg−1 respectively. Moreover, the CuO-2/C exhibits ≈ 96.1% coulombic efficiency following 1000 cycles, whereas, CuO-1/C lags in coulombic efficiency with only 51.8%. As a better candidate, CuO-2/C exhibited excellent rate capability with an outstanding cycling stability of 93.7% retention after 1,000 cycles. The factors contributing to the significant specific capacitance of CuO-2/C along with better stability and reproducibility are its low electrolyte resistance Rs (2.47Ω) and charge transfer resistance Rct (1.01 Ω).

Rare‑earth (Eu3+) substitution impact on the structural, morphological, magneto-dielectric, and electrochemical properties of 〖Cd〗_(0.45) 〖Co〗_(0.55) 〖Fe〗_(2-y) 〖Eu〗_y O_(4 )spinel nanoferrites.

A series of Cd_0.45 Co_0.55 Fe_(2-y) Eu_y O_(4 )(y = 0.0, 0.1, 0.2, 0.3) spinel nanoferrites (SNFs) were synthesized using a self-igniting process and employed as electrode materials for supercapacitor applications. The results demonstrated the formation of a single SNFs phase, as shown by the XRD data. The crystallite size lies between the range of 29.30 nm - 51.12 nm. The porosity percentage is within the range of 31.37% - 32.99%. Rietveld refinement of XRD and Raman analysis revealed the pure spinel phase and no secondary phase was observed. The saturation magnetization and magnetic anisotropy were also decreased with the addition of Eu3+ in Cd-Co SNFs. The high coercive field was enhanced for Eu3+ doping as compared to pure Cd-Co SNFs. The dielectric constant was improved with the substitution of Eu3+ in Cd-Co SNFs. The dielectric tangent loss was reduced with the doping of Eu3+. The electrochemical performance of the Eu3+ doped Cd-Co SNFs achieved an impressive maximum specific capacitance at a lower scan rate. Based on these findings, the outstanding electrochemical performance of the Eu3+ doped Cd-Co SNFs suggests their potential as promising materials for high-frequency, magnetic ferrofluid, and supercapacitor electrodes.

Cation Configuration and Structural Degradation of Layered Transition Metal Oxides in Sodium-Ion Batteries.

Given the pressing depletion of lithium resources, sodium-ion batteries (SIBs) stand out as a cost-effective alternative for energy storage solutions in the near future. Layered transition metal oxides (LTMOs) emerge as the leading cathode materials for SIBs due to their superior specific capacities and abundant raw materials. Nonetheless, achieving long-term stability in LTMOs for SIBs remains a challenge due to the inevitable structural degradation during charge-discharge cycles. The complexity and diversity of cation configurations/superstructures within the transition metal layers (TMO2) further complicate the understanding for newcomers. Therefore, it is critical to summarize and discuss the factors leading to structural degradation and the available strategies for enhancing LTMOs' stability. In this review, the cationic configurations of TMO2 layers are introduced from a crystallographic perspective. It then identifies and examines four key factors responsible for structural decay, alongside the impacts of various modification strategies. Finally, more effective and practical research approaches for investigating LTMOs have been proposed. The work aims to enhance the comprehension of the structural deterioration of LTMOs and facilitate a substantial improvement in their cycle life and energy density.

Zn3V2O7(OH)2·2H2O/MXene cathode with fast ion diffusion for highly durable zinc ion batteries.

V-based materials are considered promising candidates as cathode materials for zinc ion batteries (ZIBs). However, the inherent low conductivity of V-based compounds leads to the sluggish diffusion kinetics of Zn2+ and serious cycling capacity degradation of ZIBs. Herein, 1D Zn3V2O7(OH)2·2H2O (ZVO) nanowires were grown on monodisperse 2D Ti3C2T x MXene nanosheets via a facile microwave-assisted method. The introduction of Ti3C2T x MXenes effectively improved the conductivity and hydrophilicity of ZVO. Furthermore, the Zn2+ diffusion coefficient of ZVO/Ti3C2T x composites was enhanced to 10-7-10-8 cm2 s-1, which was superior to that of pure ZVO nanowires (10-8-10-10 cm2 s-1) and other previously reported typical V-based cathodes. The ZIBs based on the ZVO/Ti3C2T x cathode possessed an excellent discharge specific capacity of 215.2 mAh g-1 at 0.1 A g-1 and cycling stability (84% retention over 14 000 cycles at 10 A g-1). Moreover, the flexible Zn//ZVO/Ti3C2T x ZIBs using a gel electrolyte still exhibited good cycling stability and rate performance.

Electrochemical and structural performances of carbon and glass fiber-reinforced structural supercapacitor composite at elevated temperatures

The structural supercapacitor can store electrical energy and withstand structural loads while saving substantial weight in many structural applications. This study investigated the development of a structural supercapacitor with a fiber-reinforced polymer composite system and explored the operating temperature’s influence on its performance. The electrochemical and mechanical properties of structural supercapacitors beyond the ambient temperature have not yet been studied; hence, evaluating parameters such as specific capacitance, energy density, cycle life, and structural performance at elevated temperatures are highly desired. We have designed and manufactured single and parallelly connected multilayer structural supercapacitor composites in this research. Carbon fibers were used as a bifunctional component, acting both as a current collector while acting as a mechanical reinforcement. In addition, glass fibers were added as the separator which is also acting as an integral reinforcement. The electrochemical and mechanical behavior of structural supercapacitors at elevated temperatures up to 85 °C were experimentally investigated. The test results revealed that at room temperature, the developed double-cell structural supercapacitor, which demonstrated an area-specific capacitance of 1.16 mF cm−2 and energy density of 0.36 mWh cm−2 at 0.24 mA cm−2, which are comparable to current achievements in structural supercapacitor research. The structural supercapacitor’s tensile, flexural, and compression strengths were measured as 109.5 MPa, 47.0 MPa, and 50.4 MPa, respectively. The specific capacitance and energy density reached 2.58 mF cm−2 and 0.81 mWh cm−2, while tensile, flexural, and compression strengths were reduced to 70.9 MPa, 14.2 MPa, and 8.8 MPa, respectively, at 85 °C. These findings provide new comprehensive knowledge on structural supercapacitor devices suitable for applications operating within a temperature range from ambient conditions to 85 °C.

The electrochemical comparisons of reduced graphene oxide synthesized from pristine and recovered graphite from spent Li-ion batteries

Two reduced graphene oxides (rGO) were synthesized using two carbon sources, namely pristine graphite (rGO-PG), and recovered graphite (rGO-RG) (graphite recovered from spent Li-ion batteries) by modified hummers method and followed by the chemical reduction method to compare their supercapacitive performances. Their supercapacitance is found to be highly competitive and comparable with each other, except for their rate capabilities. The rate capability of rGO-RG is found to be inferior compared to rGO-PG. The supercapacitive behavior of both rGO’s was evaluated using five different aqueous electrolytes. The specific capacitance, specific energy, specific power, and columbic efficiencies exhibited by rGO-RG and rGO-PG were superior in the presence of 1 M H2SO4 and are 36 F g1, 7.1 Wh kg1, 0.88 kW kg1 and 96.55 %; and 40 F g1, 7.9 Wh kg1, 0.66 kW kg1 and 97.36 %, respectively. Both the rGOs exhibited no deterioration in their performance up to 10,000 continuous charge and discharge cycles at a current density of 10 A g1; rather, they exhibited enhancement in their performances with an increase in charge and discharge cycles. The enhancement exhibited by rGO-RG is superior to that of rGO-PG, which is 844 % (272 F g1) higher than its initial performance (29 F g1).

Facile construction of porous carbon fibers from coal pitch for Li-S batteries

Coal pitch, an important by-product in the coal coking industry with a high output, is a low-cost and high-carbon yield precursor for the manufacturing of high-value carbon materials. Herein, N/O co-doped carbon fiber (CFCP), fabricated by electrospinning using pre-oxidized coal pitch as the precursor, was employed as the sulfur host for Li-S batteries. The presence of more pyrrolic N and graphic N in CFCP than carbon fiber made from polyacrylonitrile benefits the adsorption of lithium polysulfide and the battery’s life. Sulphur-CFCP cathode (S@CFCP) exhibited excellent specific capacity and cyclability, with a specific capacity of 701.1 mAh/g and a low capacity decay rate of 0.088% per cycle over 200 cycles at 2.0 C, respectively. The high ion diffusion rate, low charge transfer resistance, and effective conversion of lithium polysulfides enable the high electrochemical performance of S@CFCP.

Structural analysis of Salvia miltiorrhiza polysaccharide and its regulatory functions on T cells subsets in tumor-bearing mice combined with thymopentin

Salvia miltiorrhiza ethanol-extracted polysaccharide (SMEP) and thymopentin (TP5) have been proved with strong immunomodulatory activity, and T cells subsets play pivotal roles in the inhibition of solid tumors growth. In the present study, the structure of SMEP was further identified via methylation and nuclear magnetic resonance spectra, and the immunomodulatory activity in combination with TP5 was investigated via evaluating T cell subsets spatial distributions in tumor-bearing mice, finally the cellular status of solid tumor cells was analyzed. The results revealed that SMEP was a neutral heteropolysaccharide using (1 → 4)-α-D-Glcp and (2 → 1)-β-D-Fruf as the main chain, along with branched chains of (1 → 6)-α-D-Galp. The SMEP+TP5 treatments could effectively promote the differentiation and improve the specific recognition capacity of CD4+ T cells in tumor-bearing mice, thereby activate tumor-infiltrating CD8+ T cells to exert cytotoxic effects, finally promoting the tumor cells apoptosis via blocking cell cycle at G0/G1 phase, which might be relevant with suppression of Wnt/β-catenin signaling pathway. These findings highlighted the potential of SMEP as an immunoadjuvant for patients bearing immune-deficiency related diseases, and provided data support for the functional researches of T cell subsets in tumor immunity.

Confinement and interface engineering boosting the capacitive performance by constructing NiCo-LDH@CoSe core-shell structure for supercapacitor

The strategic design of heterostructures in multicomponent composites is a promising approach for enhancing the properties of energy storage materials. While NiCo layered double hydroxide (NiCo-LDH) exhibits favorable ion exchange and redox capabilities, its nanostructure suffers from poor conductivity, leading to aggregation during charge and discharge cycles and compromising its electrochemical stability. This study presents the novel synthesis of NiCo-LDH@CoSe core-shell heterostructure using a two-step electrodeposition technique. The NiCo-LDH@CoSe heterojunction has remarkable electrochemical characteristics, boasting a high specific capacitance of 1965.4 F·g−1 at 1 A·g−1. It also exhibits an impressive rate performance of 74.4 % at 20 A·g−1, and retains 83.3 % of its capacitance after enduring 10,000 cycles at 30 A·g−1. The confinement and interface engineering of the heterojunction facilitate enhanced charge transfer from CoSe to NiCo-LDH, leading to exceptional performance and effectively addressing challenges such as poor conductivity, structural degradation, and nanoparticle clustering. The assembled NiCo-LDH@CoSe//AC hybrid supercapacitor also shows excellent performance. This research underscores the effectiveness of core-shell structure confinement and interface engineering in enhancing electrochemical performance.

Stable Hierarchical Porous Heterostructure Ni2P/NC@CoNi2S4 Fabricated via the NiCo-LDH Template Strategy for High-Performance Supercapacitors.

Transition metal phosphide/sulfide (TMP/TMS) heterostructures are attractive supercapacitor electrode materials due to their rapid redox reaction kinetics. However, the limited active sites and weak interfacial interactions result in undesirable electrochemical performance. Herein, based on constructing the NiCo-LDH template on Ni-MOF-derived Ni2P/NC, Ni2P/NC@CoNi2S4 with a porous heterostructure is fabricated by sulfurizing the intermediate and is used for supercapacitors. The exposed Ni sites in the phosphating-obtained Ni2P/NC coordinate with OH- to in situ form an intimate-connected Ni2P/NC@NiCo-LDH, and the CoNi2S4 nanosheets retaining the original cross-linked structure of NiCo-LDH integrate the porous carbon skeleton of Ni2P/NC to yield a hierarchical pore structure with rich electroactive sites. The conducting carbon backbone and the intense electronic interactions at the interface accelerate electron transfer, and the hierarchical pores offer sufficient ion diffusion paths to accelerate redox reactions. These confer Ni2P/NC@CoNi2S4 with a high specific capacitance of 2499 F·g-1 at 1 A·g-1. The NiCo-LDH template producing a tight interfacial connection, significantly enhances the stability of the heterostructure, leading to a 91.89% capacitance retention after 10,000 cycles. Moreover, the fabricated Ni2P/NC@CoNi2S4//NC asymmetric supercapacitor exhibits an excellent energy density of 73.68 Wh kg-1 at a power density of 700 W kg-1, superior to most reported composites of TMPs or TMSs.

CuMn2O4 spinel electrodes: effect of the hydrothermal treatment duration on electrochemical performance

CuMn2O4 (CMO) thin films are produced using a simple hydrothermal method. The influence of reaction duration on the electrodes’ electrochemical performance is investigated. XRD data shows improved crystal structure after 24-h reaction time, with a crystallite size of 12.17 nm. Distinct vibrational peaks associated with Cu–O and Mn–O are observed in the ATR-FTIR spectra, corroborating the spinel formation after 24 h. XPS analysis shows a compositional shift over time, starting with copper hydroxide at 12 h, evolving into a mix of copper and manganese oxides, hydroxides, and oxyhydroxides by 18 h, and achieving the desired spinel composition by 24 h. Microscopic analysis reveals CMO is arranged as small sheet structures, with 4.95 ± 2.92 µm in length after 24-h reaction. The CMO24h electrode displays a maximum specific capacitance of 1187.50 Fg−1 at a scan rate of 1 mVs−1 in 1 M Na2SO4 electrolyte. The electrochemical performance of the synthesized CMO electrodes reveals a high potential for energy storage applications.

In Situ Construction of Specific SEI Layer Affords Effective Prelithiation.

Silicon-based anodes have been attracting attention due to their high theoretical specific capacity, but their low initial Coulombic efficiency (ICE) seriously hinders their commercial application. Direct contact prelithiation is considered to be one of the effective means of solving this problem. By means of prelithiation, a specific solid electrolyte interphase (SEI) was constructed, which inhibited the volume expansion of the SiO/C composite anode during prelithiation and reduced the local current generated when the lithium source was in contact with the anode. On the one hand, it can reduce the side reactions derived from the decomposition of electrolytes in the prelithiation process, and on the other hand, it can slow down the prelithiation process and inhibit the volume expansion of the SiO/C composite anode in the prelithiation process. The results of XPS, TOF-SIMS, and other tests show that the use of an electrolyte whose main component is LiTFSI can construct SEI film whose main component is LiF, which to a certain extent can slow down the rate of prelithiation, reduce the local current generated when the lithium source is in contact with the negative electrode, minimize the occurrence of side reactions, and inhibit the volume expansion of the negative electrode material. The full battery assembled with NCM111 positive electrode still exhibits 83.5% capacity retention after 500 cycles at 1 C current density. These studies provide some ideas to enhance the performance of silicon-based materials.

Innovative synthesis and comprehensive electrochemical evaluation of FeVO4 for enhanced sodium-ion battery performance

Sodium-ion batteries (SIBs) are emerging as a viable alternative to the more costly and resource-constrained lithium-ion batteries (LIBs), especially in meeting the increasing need for large-scale energy storage. A significant challenge for SIBs lies in the exploration of the advanced anode materials. FeVO4 (FVO) nanoparticles were synthesized through both wet chemical and solid-phase methods by using citric acid monohydrate and ferric nitrate nonahydrate as blowing agents. XRD and TEM characterization reveals the presence of a large (101) interlayer spacing (∼4.46 Å) that accommodates the insertion and extraction of sodium ions (Na+). As anode material for storing Na+, FVO demonstrates an impressive discharge capacity of 326.5 mAh g−1 when cycling at a rate of 0.1 A g−1 over 300 cycles. In addition, the NaFePO4||FeVO4 full cell provides a discharge specific capacity of 102.8 mAh g−1 at 0.1C (1C = 154 mAg−1). The dynamic properties of the FVO/Na battery are revealed by pseudo-capacitance analysis and GITT tests. Meanwhile, the storage mechanism of Na+ is further analyzed by XPS, TEM, in-situ XRD and density functional theory calculations. Overall, this work presents new insights into the application of FeVO4 in SIBs and also demonstrates the competitive potential of FeVO4 for energy storage.

Spatially Confined Engineering Toward Deep Eutectic Electrolyte in Metal-Organic Framework Enabling Solid-State Zinc-Ion Batteries.

Uncontrollable interfacial side reactions generated from common aqueous electrolytes, just like the hydrogen evolution reaction (HER) and dendrite growth, have severely prevented the practical application of zinc-ion batteries (ZIBs). Solid-state ZIBs are considered to be an efficient strategy by adopting high-quality solid-state electrolytes (SSEs). Here, by confining the deep eutectic electrolyte (DEE) into the nanochannels of the metal-organic framework (MOF)-PCN-222, a stable DEE@PCN-222 SSE with internal Zn2+ transport channels was obtained. A distinctive ion-transport network composed of DEE and PCN-222 in the interior of DEE@PCN-222 realizes the efficient Zn2+ conduction, contributing to a high ionic conductivity of 3.13 × 10-4 S cm-1 at room temperature, a low activation energy of 0.12 eV, and a high Zn2+ transference number of 0.76. Furthermore, experimental and theoretical investigations demonstrate that DEE@PCN-222 with its unique channel structure could homogeneously regulate the Zn2+ distribution and effectively alleviate the side reactions. Highly reversible Zn plating/stripping performance of 2476 h can be realized by the SSE. The solid-state ZIBs show a specific capacity of 306 mAh g-1 and display cycling stability of 517 cycles. This unique design concept provides a new perspective in realizing the high-safety and high-performance ZIBs.

Rational design of dual-ion doped cobalt-free Li-rich cathode materials for enhanced cycle stability of lithium-ion pouch cell batteries.

The synergistic effect of single-crystal structure and dual doping in Li-rich cobalt-free cathode materials was thoroughly investigated. Lithium-ion pouch cells employing Sb/Sn doped Li1.2Mn0.6Ni0.2O2 and graphite exhibited a specific capacity of 191.01 mA h g-1 at 1C rate and exceptionally stable performance upon cycling, with capacity retention of 87.24% of their initial capacity after 250 cycles at 1C rate. The strategic combination of morphology manipulation and dual ion doping has markedly diminished cation mixing and expanded the Li interstitial sites within the cathode lattice. This work offers significant insights into the mechanisms responsible for the structural decline of Li-rich cobalt-free cathodes, emphasizing the importance of stabilizing the cathode lattice structure at high potential. These findings suggest promising potential for this material to meet the demanding energy density criteria for electric vehicles. Finally, this research provides practical strategies for effectively implementing high-voltage cobalt-free cathodes, offering valuable guidance for future applications.

Unlocking 4.9 V Quasi-Solid-State Lithium Metal Battery via Solvent Screening and Interfacial Manipulation.

Parlous structure integrity of the cathode and erratic interfacial microdynamics under high potential take responsibility for the degradation of solid-state lithium metal batteries (LMBs). Here, high-voltage LMBs have been operated by modulating the polymer electrolyte intrinsic structure through an intermediate dielectric constant solvent and further inducing the gradient solid-state electrolyte interphase. Benefiting from the chemical adsorption between trimethyl phosphate (TMP) and the cathode, the gradient interphase rich in LiPFxOy and LiF is induced, thereby ensuring the structural integrity and interface compatibility of the commercial LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode even at the 4.9 V cutoff voltage. Eventually, the specific capacity of NCM811|Li full cell based on TMP-modulated polymer electrolyte increased by 27.7% from 4.5 to 4.9 V. Such a universal screening method of electrolyte solvents and its derived electrode interfacial manipulation strategy opens fresh avenues for quasi-solid-state LMBs with high specific energy.

Utilizing rubber plant leaf petioles derived activated carbon for high-performance supercapacitor electrodes

This research introduces a novel and sustainable method that exploits the untapped potential of waste biomass, specifically converting dead leaf petioles from Ficus elastica, an industrial crop commonly known as rubber plants, into high-performance activated carbon (AC) for supercapacitor electrodes through a straightforward pyrolysis process. The prepared AC is used as an electrode substance to construct symmetrical supercapacitors. It underwent detailed morphological and structural analyses through various analytical instruments to assess the AC's performance and quality. Electrochemical assessments using a two-electrode configuration with 1 M KOH as the electrolyte revealed that the AC electrodes display exemplary characteristics of electric double-layer capacitance. This conclusion was drawn from observing cyclic voltammetry curves that were rectangular and symmetrical across scan rates ranging from 10 to 100 mV/s. Remarkably, at a scan rate of 10 mV/s, these AC electrodes achieved a specific capacitance of 128 F/g. The superior performance of the AC, when compared to other biomass-derived electrode materials, can be attributed to its extensive surface area and significant porosity. Moreover, electrodes crafted from AC derived from rubber plants showed remarkable durability over 10000 charge-discharge cycles, maintaining 89 % of their original capacitance and achieving a Coulombic efficiency of up to 87 %. During prolonged discharge periods, these electrodes exhibited a high specific capacitance, which contributed to achieving a power density of 200 W/kg and an energy density of 11.4 Wh/kg. This study highlights the viability of rubber plant waste in advanced energy storage systems and significantly contributes to sustainable material science. By offering an eco-friendly approach for supercapacitor electrode fabrication, this research aligns with global efforts towards sustainable energy storage technologies, demonstrating the practicality of environmentally benign materials in high-performance applications.

Unveiling the electrochemical excellence of sulfur and nitrogen-enriched 3D porous carbon nanofibers in high-performance energy storage devices

Recent research has faced challenges in achieving high specific capacitance and cycle stability with carbon nanofibers (CNFs) as supercapacitor electrodes. This study employs calcination/activation techniques to modify the electrochemical and structural properties of electrospun sulfur/nitrogen (S, N)-enriched CNFs. Combining the electrospinning process with these methods produces CNFs with a high energy density, enhancing non-faradaic processes. The 3D interconnected morphology of S, N-enriched CNFs possesses an appropriate surface area of 104.1 m2/g at 77 K with the high porous nature. Due to the excellent synergistic effect of nitrogen and sulfur atoms, the as-prepared porous CNFs showed excellent electrochemical performance in a three-electrode assembly. Under a neutral medium, the symmetric two-electrode cell displayed an outstanding electrochemical performance with a specific capacitance of 186F/g, an energy density of 25.8 Wh kg−1, a power density of 500 W kg−1 and excellent capacitance retention of 88.2 % over 3000 charge–discharge cycles. The findings strongly indicate that the as-prepared CNFs have the potential to advance significantly energy storage technology, surpassing other reported carbon materials.