Supercapattery Device Research Articles

Enhanced cathodic electrodes from V2O5 nanorods: Pioneering organic dye degradation and optimized catalysis for sustainable supercapattery devices

Encapsulating the essence of multifunctionality, the synthesized Vanadium Pentoxide (V2O5) nanorods (NRs) are adaptable innovators of visible-light photocatalytic degradation and sustainable supercapattery device fabrication. Meanwhile, the physicochemical properties are investigated by precise instruments. The V2O5 NRs demonstrate improved photocatalytic performance over a 100-min duration, effectively catalyzing the methylene blue (MB) degradation with a remarkable degradation percentage of 98.37 % (25 mg catalysis) and shows a lower wavelength shift due to MB molecular braking. In a groundbreaking twist, this work utilises tainted V2O5 NRs, ingeniously repurposing them to energy storage tenacities. In addition, the electrochemical assessment of tainted V2O5 NRs demonstrated subtle changes after MB degradation, increasing the specific capacity (Cs) value from 794 to 933C.g−1 due to developing reduced particle agglomeration. Moreover, the better Cs value of tainted V2O5 NRs reached 95.02 % after 500 cycles (5 A.g−1). The fabricated asymmetric supercapattery (ASC) device demonstrates superior ion diffusion processes, as evidenced by Dunn's method calculations, particularly at a scan rate of 5 mV.s−1. Additionally, the assembled device underscored their unique positioning between battery and capacitor materials, distinctly supported by a “b” value of 0.8 and superior capacity retentivity. They reached a superior power (P = 191.75 W.kg−1) with energy (E = 50 Wh.kg−1) and better cyclic stability, maintaining their performance over 4000 cycles at 5 A. g−1 (91.3 %). Furthermore, under exposure to the light of a yellow light emitting diode (LED) for 30 s, the real-time consequences of after cyclic stability material of tainted V2O5 NRs are investigated, providing meaningful insights into their performance dynamics.

Enhancing the electrochemical efficiency of metal-organic frameworks through integration of chromium nitride interfacial layer for efficient hybrid supercapacitors

Transition metal nitrides are highly stable and electrochemically efficient, making them a promising material for supercapacitor electrodes. Herein, for assessing the synergistic effects of metal-organic framework via transition metal nitrides, we synthesized chromium nitride electrode using magnetron sputtering followed by the deposition of copper-trimesic acid. Electrochemical testing in half and full cell configurations reveals that chromium nitride/copper-trimesic acid has the lowest charge transfer resistance, indicating its quick charge transport pathways, leading to an increased specific capacity (1651C/g at 1.5 A/g) and notable rate capability. Persuaded by the exceptional capacitive and charge storage potential, a two-cell mode-based hybrid supercapacitor was fabricated using activated carbon and chromium nitride/copper-trimesic acid. This combination demonstrated the highest energy density of 94.5 Wh/kg, maximum power density of 7750 W/kg while functioning at 1.6 V with cycling stability of 97.9 % after 3000 galvanostatic charge discharge cycles. Additionally, for examining the diffusive and capacitive behaviors of devices, two different semi-empirical models were further used and compared, which shed light on the special characteristics and implementation of supercapattery device.

Al intercalated ZnS nanosheets as anode for supercapattery application with wide operating potential window

Selection of electrode material and operating potential window are important factor affecting the specific capacitance, energy density and stability of energy storage devices. Pristine ZnS has attracted the researchers to be focused for electrochemical performance due to its high theoretical capacitance, easy fabrication, low cost and environmental friendliness. Herein, we report successful fabrication of Al intercalated ZnS (Al1.6Zn80.9S17.5) nanosheets to optimize the structure, morphology and electrochemical performance as anode material for supercapattery application. Al-ZnS (Al1.6Zn80.9S17.5) is operated at wider potential window −0.3 to 0.8 to achieve an excellent specific capacitance of 1414 Fg−1 along with high energy density of about 90 Whkg−1 at 6540 WKg−1 power density, much higher than pristine ZnS (0 to 1.6 V, 705 Fg−1). The different current controlling mechanisms has also been analyzed by theoretical study using Dunn’s differentiation method. The reported wide potential window offers the opportunity to develop asymmetric supercapattery device that can operate at broaden potential window. Furthermore, Al-ZnS//rGO supercapattery device operating at 1.5 V potential is constructed using Al-ZnS as anode and rGO as cathode. Al-ZnS//rGO supercapattery device demonstrates an excellent specific capacitance of approximately 250 Fg−1 and energy density of about 140 Whkg−1 at 5800 WKg−1. The designed supercapattery device also exhibits 98 % columbic and capacitance retention of 90 %. The designed work elaborates on new guidelines for novel electrode material and explores the possibility of achieving the wide potential windows that can be utilized for practical energy storage applications.

Faradically dominant pseudocapacitive graphitic carbon nitride nanosheets decorated with strontium tungstate nanospheres for supercapattery device and hydrogen evaluation reaction

Transition metal oxides are promising for hydrogen evolution reaction (HER) and hybrid energy storage due to their excellent redox properties, inherent electrochemical activity, and abundant electroactive sites. A significant challenge limiting their broader application is their intrinsic low electrical conductivity and reduced electrochemical stability. For hybrid energy storage devices and HER, a highly electrochemical active material is designed from 2D graphitic carbon nitride nanosheet (g-C3N4) networks anchored with strontium tungstate nanospheres (SrWO4/g-C3N4). The excellent performance observed can be attributed to several factors: multiple electro-active sites, well-defined electronic structures, and interaction between SrWO4 nanosphere on the surface of g-C3N4 nanosheets surface. The supercapattery device exhibited superior energy density (65.4 W h/kg) and power density (1240.5 W/kg) in comparison. In addition, the theoretical technique was utilized to provide a detailed analysis of the experimental findings. In addition, the SrWO4/g-C3N4 material demonstrates a low overpotential of 129 mV at -10 mA/cm2, along with Tafel slope values of 67 mV/dec for the HER, and it exhibits excellent cyclic stability. This study presents an advanced method for designing SrWO4/g-C3N4-based supercapacitors and HER platforms with nanoscale structures and optimized interface arrangements.

Designing of a High Performance NiMgPO4/CNT Electrode Material for a Battery-Supercapacitor Hybrid Device

Improved pseudo-capacitance performance can be obtained by phosphates and transition-metal oxides by achieving oxidation states that boost redox (reduction-oxidation) processes. In this work, the nickel magnesium phosphate (NiMgPO4) is synthesized using the hydrothermal method, Additional, carbon nanotubes (CNTs) are blended with NiMgPO4. To build the supercapattery device (NiMgPO4@CNT//AC) and evaluate its electrochemical characteristics, we used NiMgPO4@CNT as the anode & activated carbon as cathode. We also used X-ray diffraction, scanning electron micrscopy, Brunauer–Emmett–Teller, and X-ray photoelectron spectroscopy techniques to analyze the crystal structure, surface area, and elemental composition. The nanocomposite NiMgPO4@CNT demonstrated a high specific capacity of 1243 C g−1 or 2071.66 F g−1 in a three-electrode system, which was much more than that of the separate reference materials. The supercapattery device shows a specific capacity of 251 C g−1, energy density of 44.5 Wh kg−1 and power density of 1030 W kg−1 is observed. The hybrid electrode exhibited a capacity retention of 85% after 5000 cycles and a columbic efficiency of 91% during the stability measurement. These findings emphasize NiMgPO4@CNT’s potential as an electrode composite material that holds promise for high-performance supercapattery device building.

Copper-Based Para-Phthalic Acid Metal-Organic Framework: An Efficient Anodic material for Super-capattery Hybrid Systems

The battery-supercapacitor hybrid, an asymmetric energy storage system, has garnered considerable attention due to its outstanding energy storage capabilities. Anodic materials have become a central focus, driven by the quest for enhanced energy density, power density, cycle life, and overall performance. In this study, we have synthesized copper-based para-phthalic acid (PTA) metal-organic frameworks (MOFs) via a facile hydrothermal method to be employed as the positive electrode material in a battery-supercapacitor hybrid matrix. The initial testing indicates the battery-type nature of the prepared electrode along with maximum specific capacity of 260.5 C g-1 at 0.7 A g-1. Subjection of Cu-PTA MOF electrode to real device configuration (Super-capattery device) results in considerable specific capacity of 152.2 C g-1 along with specific energy and power of 35.9 Wh kg-1 and 5950 W kg-1, respectively at 0.3 A g-1. The device also demonstrated a stability potential of 92.15% when tested for 5000 continuous charge-discharge cycles. The present study presents Cu-PTA MOF an exciting addition for advancing current state of research in the field of energy storage technology.

Green synthesis of CoVS2-MOF@CMS nanocomposite electrode for sustainable approach towards eco-friendly energy storage and dopamine detection

Dopamine, a crucial brain chemical belonging to the catecholamine and phenethylamine chemical families, plays a vital role in promoting a healthy and happy life. Irregular dopamine release has been linked to various neurological disorders and depressive conditions. Therefore, conducting real-time, in vivo monitoring of dopamine levels is essential to gain a comprehensive understanding of its physiological functions. In this research, the hydrothermal technique was employed to synthesize copper‑molybdenum sulfide (Cu2MoS4 (CMS)). Further, we have reported the one-pot hydrothermal synthesis of CoVS2-MOF, using the bioactive chemical as fuel obtained from Euphorbia cognata Boiss. The specific capacity (Qs) of the sample CoVS2-MOF@CMS was calculated to be 820 Cg−1 at 3 mVs−1, a value expressively higher than that of the reference samples. Furthermore, in the supercapattery device, an outstanding Qs of 300 Cg−1 was achieved at 1.5 Ag−1, surpassing the previously observed values. The device demonstrated outstanding performance, including a coulombic efficiency of 89 %, a specific energy of 36.68 Whkg−1, and a power density (Pd) of 2218.53 Wkg−1. Moreover, the sensor typically yielded dopamine (DA) concentrations in human serum ranging from 100.8 % to 102.2 %. The utilization of the multifunctional CoVS2-MOF@CMS nanocomposite electrode material illustrates promising prospects for the fabrication of hybrid devices with applications in biomedical and energy harvesting fields.

A novel binary composite of CuCoNi-MOF/MoO3 with exceptional capacitance as electrode material for supercapacitors

Metal-organic framework (MOF), a new type of electrode material with a porous structure, has shown promise as a good choice for supercapacitors in the next generation of energy storage devices. These research endeavors initiated the development of a doping technique and the creation of a composite material using solvothermal synthesis. This study involves the successful synthesis of CuCo-MOF and CuCoNi-MOF by introducing Co and Ni metals into the Cu-MOF. The CuCoNi-MOF is then combined with MoO3 to form a novel binary composite known as CuCoNi-MOF/MoO3. These prepared materials are then subjected to several physiochemical and electrochemical characterization techniques. The electrochemical characteristics of the prepared samples are estimated using a three-electrode cell setup. The analysis included cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge (GCD). The examination of the CV reveals that the binary composite CuCoNi-MOF/MoO3 exhibits exceptional capacitance (937.5 Fg−1 at 5 mVs−1) in comparison to the other materials that were synthesized. Moreover, the GCD study reveals that it has a capacity of 1364.69 Fg−1 at 0.5 Ag−1. Furthermore, it retained 91.5 % of its capacity after 5000 cycles demonstrating its exceptional stability. Owing to the exceptional electrochemical properties of CuCoNi-MOF/MoO3, it is employed as the positive electrode and activated carbon (ActC) as a negative electrode for device fabrication. The supercapattery (CuCoNi-MOF/MoO3||Act-C) showed an excellent specific capacitance of 218.83 Fg−1 at 1 Ag−1 along with an outstanding energy density of 59.57 Wh.kg−1 and power density of 704.9 W.kg−1. Moreover, the assembled supercapattery device shows remarkable stability of 95.2 % at 10 Ag−1 after 15,000 cycles.

Zinc manganite as an efficient battery-grade material for supercapattery devices

In the current context, supercapatteries emerge as highly desirable candidates capable of merging both energy and power density within a single device. Battery-type metal oxide materials, combined with capacitive-based materials, stand out as promising candidates for high-performance supercapatteries. This investigation centers on the synthesis of nanocrystalline ZnMn2O4 (ZMO) and CoMn2O4 (CMO) through a straightforward hydrothermal method, followed by their physico-electrochemical characterization. Electrochemical analysis reveals that ZMO exhibits notably enhanced charge storage capability compared to CMO. This superiority can be attributed to favourable electro-structural properties, and stable redox chemistry of ZMO. The real-time performance of ZnMn2O4 was further assessed by fabricating a hybrid asymmetric supercapattery device (ZnMn2O4||NrGO), which achieves a specific capacity of 232 C g−1 at a current density of 1 A g−1. The hybrid asymmetric device underwent rigorous stability testing for 4000 cycles at a current density of 2 A g−1, showcasing remarkable performance with a 92 % retention of its initial capacity. The device demonstrated a power density of 980 W kg−1 and an energy density of 63 Wh kg−1, highlighting its considerable promise in the field.

All colloidal supercapattery: colloid@carbon cloth electrodes meet "water‐in‐salt" electrolyte

The pursuit of excellent electrochemical performance, nonflammability and environmental friendliness of aqueous batteries and supercapacitors has driven efforts to find high‐energy yet reliable electrode materials and electrolyte solutions. Here, all colloidal supercapattery are developed using high‐concentration "water‐in‐salt" electrolytes (LiTFSI‐KOH) and pseudocapacitive colloid@carbon cloth as both positive and negative electrodes, which showed merits of batteries and supercapacitors. Ni/Co‐colloid @carbon cloth positive and Fe‐colloid @carbon cloth negative electrodes can be synthesized by in situ electrochemical reaction. The maximum operating voltage of an aqueous colloidal supercapattery is 1.8 V, and the energy density can reach 73.98 Wh kg−1 at a power density of 1799.5 W kg‐1. The specific capacitance of the aqueous colloidal supercapattery still maintains 74.3% of the initial after 2000 cycles of charge/discharge measurement. The combination of quasi ion colloidal materials and "water‐in‐salt" electrolyte pave a profound way to achieve high energy and power ability simultaneously at the supercapattery device.

Superior Electrochemical Performance and Cyclic Stability of WS2@CoMgS//AC Composite on the Nickel-Foam for Asymmetric Supercapacitor Devices

Two-dimensional (2D) sulfide-based transition metal dichalcogenides (TMDs) have shown their crucial importance in energy storage devices. In this study, the tungsten disulfide (WS2) nanosheets were combined with hydrothermally synthesized cobalt magnesium sulfide (CoMgS) nanocomposite for use as efficient electrodes in supercapattery energy storage devices. The characteristics of the WS2@CoMgS nanocomposite were better than those of the WS2 and CoMgS electrodes. XRD, SEM, and BET analyses were performed on the nanocomposite to examine its structure, morphology, and surface area in depth. In three-electrode assemblies, the composite (WS2@CoMgS) electrode showed a high specific capacity of 874.39 C g−1 or 1457.31 F g−1 at 1.5 A g−1. The supercapattery device (WS2@CoMgS//AC) electrode demonstrated a specific capacity of 325 C g−1 with an exceptional rate capability retention of 91% and columbic efficiency of 92% over 7000 cycles, according to electrochemical studies. Additionally, the high energy storage capacity of the WS2@CoMgS composite electrode was proved by structural and morphological investigations.

Electrochemical Investigation of ZnS/NiO Nanocomposite based Symmetric Supercapattery

AbstractSupercapattery is an ideal energy storage device combining the features of supercapacitors and batteries, offers a high‐energy density as well as high‐power density with extended operational lifespan. In this work, zinc sulfide (ZnS) and zinc sulfide/nickel oxide (ZnS/NiO) nanocomposite was synthesized via chemical coprecipitation method and characterized using state‐of‐the‐art analytical tools. The ZnS/NiO electrode exhibited remarkable electrochemical performance as an electrode material than pure ZnS. The ZnS/NiO nanocomposite exhibited high crystallinity, and spherical nanoparticles with an average grain size of 20–40 nm having a homogeneous dispersion. The ZnS/NiO electrode exhibited an ultrahigh specific capacity of 1803.87 Cg−1 at a relatively low scan rate of 10 mVs−1 in a 1 M KOH solution from cyclic voltammetry and 393 Cg−1 at 16 Ag−1 from charge discharge measurements, and it showed exceptional cycling stability (98 % capacity retention after 1000 cycles). Furthermore, the ZnS/NiO symmetric supercapattery device exhibited 44.43 Fg−1 specific capacitance, 5.52 Wh kg−1 energy density, and 1600 Wkg−1 power density at current density of 0.8 Ag−1 in 1 M KOH solution from galvanostatic charge discharge. After 3000 cycles, the ZnS/NiO nanomaterial demonstrated promising cyclic stability of 95 %. The ZnS/NiO supercapattery nanocomposite might be considered as a potential hybrid electrode material for the future development of electrochemical energy storage devices.

Synergistic Advancements in Battery-Grade Energy Storage: AgCoS@MXene@AC Hybrid Electrode Material as an Enhanced Electrocatalyst for Oxygen Reduction Reaction

The extreme usage of fossil fuels and the rising conservation deterioration have made developing clean, renewable energy essential. Among the most promising methods for addressing the world’s energy dilemma are electrochemical energy storage devices (EES); batteries and supercapacitors (SCs) are two typical components in this class. Supercapacitors are incredibly impressive since they can store energy remarkably in seconds. In this work, we present a highly effective electrode material (AgCoS@MXene) for supercapattery device application that is produced hydrothermally. We examined the morphology and crystallinity of the synthesized materials using SEM and XRD studies. The synthesized compounds were subjected to a thorough electrochemical performance study employing a three-electrode configuration in a 1 M KOH electrolyte. AgCoS@MXene demonstrated an exceptional Qs of 943.22 C g−1 at a current density of 2.0 A g−1. We formed a supercapattery device (AgCoS@MXene//AC) with AgCoS@MXene as the positive electrode and activated carbon (AC) as the negative electrode. The supercapattery device was demonstrated to have a high specific capacity of 315.22 C g−1, a power density of 1275 W kg−1, and an energy density of 35.94 Wh kg−1. In addition, 5000 charging and discharging cycles were used to assess the device’s long-term longevity. The findings indicated that the device preserved nearly 82% of its initial capacity. Besides, the hybrid electrode is used for the electrocatalytic activity for the oxygen reduction reaction. These promising findings imply that AgCoS@MXene is a beneficial electrode material for upcoming energy storage devices to enhance the electrocatalytic activity for the oxygen reduction reaction.

Enhanced energy storage performance of copper intercalated redox active 1, 2, 4, 5-benzene-tetracarboxylic Acid organic framework

Supercapattery being remarkable energy storage device combining the strength of supercapacitors and batteries can offer both high power and enhanced energy storage capabilities. In the realm of advanced materials, Metal-Organic Frameworks (MOFs) represent a unique category of porous materials formed through strong bonds between organic linkers and metal ions. Through meticulous ingredient selection, MOFs can exhibit extremely large surface areas, exceptional chemical stability, and significant pore volumes. In this study, we demonstrate the electrochemical energy storage performance of copper intercalated MOF (Cu-MOF) synthesized via a hydrothermal method for the application of supercapattery. Initially, we employed a three-electrode assembly to scrutinize the electrochemical characteristics of the synthesized material. To investigate the nature of the electrodes, electrochemical analysis including cyclic voltammetry (CV), galvanostatic charge discharge (GCD), and electrochemical impedance spectroscopy (EIS) were performed. The synthesized material exhibited excellent specific capacity of 403.5 C/g at 1.5 A/g, indicating its battery-grade quality. Due to its superior electrochemical performance, the supercapattery device was fabricated by coupling Cu-MOF with activated carbon (AC), Cu-MOF was subjected to positive and AC was employed as the negative electrode. The Cu-MOF//AC exhibited remarkable specific capacity of 165 C/g at 0.7 A/g. Furthermore, this device showcased impressive specific energy of 40 Wh/kg at specific power of 567 W/kg. The device demonstrated an impressive maximum specific power of 6336 W/kg, while its exceptional stability of 95.6 % was demonstrated through 5000 cycles at room temperature. The performance of fabricated device was also evaluated using a theoretical model to assess the diffusive and capacitive contribution. The hybrid characteristics of the devices were investigated using a power law.

ZnS@Fe2O3 core–shell nanorod arrays for supercapattery applications; theoretical evaluation of faradic and non-faradic behavior using Dunn’s model

Supercapattery has emerged as an ideal energy storage device that has the features of both batteries and supercapacitors. In this work, ZnS@Fe2O3 core–shell nanorod arrays supported on Ti foil have been prepared by the cost-effective, efficient, and facile two-step hydrothermal method and investigated for high performance supercapattery applications. The X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) confirm the successful synthesis of the material, while the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images clearly show the successful deposition of the Fe2O3 shell over the ZnS core. Electrochemical characterizations including cyclic voltammetry, galvanostatic charge discharge and electrochemical impedence spectroscopy have been employed to investigate the electroactive nature of the materials. It is found that the ZnS@Fe2O3 exhibits excellent specific capacitance of 681 Fg−1 at 1 Ag−1 current density within the potential window of −0.2 to 0.75 V while demonstrating a significant capacitance retention of 85 % and 95 % coulombic efficiency over 2000 cycles. The contribution of faradic and non-faradic processes during electrochemical reactions is evaluated using Dunn’s model. The diffusion controlled mechanism is greater than the surface controlled mechanism in the synthesized material, which depicts the battery grade nature. Interestingly, the electrode was able to exhibit an excellent energy density of 86 Whkg−1 and a maximum power density of 4232 Wkg−1, which is significantly higher than the previously reported ZnS based and Fe2O3 based composites. A Supercapattery device has been assembled using ZnS@Fe2O3 as anode and reduced grapheme oxide (rGO) as cathode, which demonstrate a specific capacitance of 165 Fg−1 at 1 Ag−1 current density, exhibiting 66 Whkg−1 at power density of 3895 Wkg−1 with excellent retention in specific capacitance and coulombic efficiency at 15 Ag−1 after 3000 cycles.

Role of pore hierarchy and Mn incorporation on the electrochemical performance of bimetallic NiMn-LDHs on graphite foil for supercapattery application

In this work, nickel-manganese layered double hydroxides (NiMn-LDHs) are synthesized using hexamethylenetetramine (HMTA) and urea as precipitating agents via hydrothermal synthesis route. The materials have different flower like microstructure and porosity. The effect of microstructures, porosity and mass loading of the LDHs on the overall electrochemical performance is thoroughly studied in this work. It is observed that HMTA assisted NiMn-LDH having open flower like microstructure delivers a high specific capacity of 719 C g−1 at 1 A g–1 and excellent capacity retention of 82.6% and 86% for 10,000 CV and 5000 GCD cycles, respectively. Furthermore, a supercapattery device assembled using NiMn-LDH@HMTA as cathode and activated carbon as anode exhibit high-capacity retention of 80.1% after 5000 GCD cycles along with an energy density of 50 and 34 Wh kg–1 at power densities of 800 and 4000 W kg–1, respectively.

Bio-extract mediated green synthesis of bi-functional ammonium cobalt phosphate nanoflakes electrode/catalyst for supercapattery and ethanol oxidation

The present study proposes a low-cost, green technique to the synthesis of bi-functional ammonium cobalt phosphate for energy storage and conversion applications. The comprehensive physiochemical investigations are carried out using various spectral-analytical techniques. The results of phase and surface morphology confirm the formation of an orthorhombic crystal structure with flakes-like microstructure. With a maximal specific capacity of 448.3 mAhg−1 at 2 mAcm−2, bio-solvent driven NH4CoPO4·H2O with graphene oxide (GO) nanoflakes demonstrates exceptional battery-type energy storage capabilities. As constructed supercapattery device exhibits a high specific energy of 85.4 Wh kg−1 at power output of 1283 W kg−1 and 81 % stability after 5000 cycles. Further exploration as a non-precious metal-based catalyst for ethanol oxidation reaction (EOR), NH4CoPO4·H2O /GO showed a high peak current density of 83.4 mAcm−2 at 20 mVs−1. Coupled oxygen/hydrogen evolution processes are investigated in 1 M KOH in order to acquire a better understanding of the catalyst's EOR activity. The NH4CoPO4·H2O/GO sample exhibited the lowest overpotentials of |ηOER@10| = 420 mV, and |ηHER@10| = 112 mV, with Tafel slopes of 169.8 mV dec−1 for OER and 132.8 mV dec-1 for HER, respectively. This is due to the catalyst's slow OH adsorption during OER and the limited H*recombination during HER. Therefore, this approach provides a green and cost-effective method to synthesis efficient bi-functional electrode/catalysts for supercapattery and alkaline fuel cells.

Exploring the potential of Withania somnifera-mediated Ag/Mn3O4 nanocomposites as electrode material for high-performance supercapattery device

Background: In this work, a bioengineered symmetric electrode material (anode, cathode) for energy storage devices was successfully demonstrated. Methods: Using Withania somnifera, Ag/Mn3O4 nanocomposite was prepared through sol-gel-assisted green synthesis. Physicochemical properties of Ag/Mn3O4, 431 nm (Ag), 315 nm (Mn3O4) in UV–visible analysis, metal (Ag) and metal oxide (Mn3O4) bonds, crystallinity index with a crystallite size of ∼29 nm from the XRD studies, rod-like morphology (SEM analysis), elemental composition (EDAX analysis), and chemical states (Ag 3d and Mn 2d) were identified through XPS studies. Significant findings: The cyclic voltammetry profiles of Ag/Mn3O4 exhibit the supercapattery behaviour with a specific capacitance of 254 F/g at a scan rate of 5 mVs−1 and a cyclic retention of 92.3 %. The fabricated symmetric supercapattery device (SSD) has an energy density of 18.5 Whkg−1 and a power density of 2084 Wkg−1. The stability of the complex is also studied in theoretically.

Designing high-performance polyaniline @MoS2@AC hybrid electrode for electrochemical–based Next-generation battery-supercapacitor hybrid energy storage device and hydrogen evolution reaction

Polyaniline (PANI), a conducting polymer, has attracted the attention of researchers as a potential candidate due to its higher capacitance and outstanding electrochemical reversibility. In this research, we used the hydrothermal approach to synthesize MoS2@PANI hybrid electrode material that may overcome the low cyclic stability of PANI. The composite material MoS2/PANI (with M/P-25/75 wt%) demonstrated a specific capacity (Qs) with the amount 1087.5 C g−1 or 1812.5 F/g, much more advanced than reference samples due to the hybrid structural integrity and enhancement of the specific surface area of MoS2 and PANI interaction through electrostatic repulsion and hydrogen bonding. The asymmetric device (MoS2/PANI-25/75wt%//AC) demonstrated an extraordinary value of a Qs of 361 C g−1 over pure PANI. This novel supercapattery device showed a supreme high energy density of 65.33 Wh kg−1 and a power density of 1668.83 W/kg. Further, the hybrid electrode is used for the hydrogen evolution reactions and obtained the value of over potential is 43 mV. A small value of the Tafel slope of 39 mV/dec is observed with high stability. The improved energy storage capabilities of MoS2/PANI hybrid electrodes with multiple applications provide a new paragon to design unusual and fast multi-functional devices.

Anion containing novel porous Manganese-1,2,4-triazolate frameworks as battery-type electrode materials for supercapattery devices

Metal-organic frameworks (MOFs) have sparked much attention as electrode material for supercapattery devices due to their unique characteristics, providing porous structures with high surface areas and desirable pore sizes. Three new Mn-organic frameworks were solvothermally synthesised using three different manganese salts (MnX2·4H2O, where X = Cl, Br and NO3) with 1,2,4-triazole (Htrz) ligands. The newly synthesised UPMOFs (Universiti Putra Metal-organic Frameworks) denoted as UPMOF-4[Mn(Htrz)(DMA)Cl], UPMOF-5[Mn(Htrz)(DMA)Br] and UPMOF-6[Mn(Htrz)(DMA)NO3] showed a promising BET surface area of 1758 m2/g, 1724 m2/g and 895 m2/g. Then, the supercapattery device was fabricated using the battery-graded UPMOFs as positive electrodes sandwiched with activated carbon (AC) as a negative electrode. The designed supercapattery devices delivered good specific capacities and specific energies. After 5000 cycles, the UPMOFs showed promising capacity retention of 90.01 % (UPMOF-4), 85.2 % (UPMOF-5) and 76.4 % (UPMOF-6) indicating good stability. Thus, to compare the electrochemical performances among the UPMOFs, a theoretical calculation using the density functional theory (DFT) was performed. The DFT calculation of these UPMOFs revealed that UPMOF-4 had the lowest HOMO-LUMO energy gap (Egap) of 0.211 eV followed by UPMOF-6 (0.777 eV) and UPMOF-5 (1.198 eV). The UPMOF-4 with good framework stability, low Egap and large BET surface area contribute to its promising electrochemical performance.