Flexible Asymmetric Supercapacitor Research Articles

Magnetron Sputtered SnO₂ Layer Combined with NiCo−LDH Nanosheets for High‐Performance All‐Solid‐State Supercapacitors

AbstractNickel‐cobalt layered double hydroxide (NiCo−LDH) has attracted much attention because of its excellent electrochemical properties and regulability. And it is a potential pseudocapacitive electrode material, which is commonly used in supercapacitors and lithium‐ion batteries. Its application in the field of supercapacitors can improve the energy density, power density and cycle life of devices. However, NiCo−LDH still faces some challenges, such as poor electrical conductivity and the capacity attenuation caused by agglomeration of layered structures, which require further research and optimization. In this paper, SnO2 films were prepared on carbon cloth (CC) by magnetron sputtering method, and Ni−Co LDH nanosheets were grown by hydrothermal reaction to obtain NiCo−LDH@SnO2 composites. Due to the synergistic effect between NiCo−LDH and SnO2, NiCo−LDH@SnO2 composites exhibit high Cs and good cyclic stability. In addition, an all‐solid‐state flexible asymmetric supercapacitor (ASC) was assembled with activated carbon (AC) anodes, showing good specific capacitance(Cs) and energy density. And a high initial capacitance can still be retained after 10,000 cycles. This paper shows that NiCo−LDH@SnO2 shows excellent application potential in supercapacitors.

Revealing 1T-MoS2 with 76 % purity induced by various saccharides for supercapacitor performance

The preparation of metallic phase molybdenum disulfide (1T-MoS2) through an implementable method has become a top priority in research due to its excellent electrochemical performance. In this study, 1T-MoS2 using a facile one-pot hydrothermal method is successfully synthesized by incorporating saccharides. Moreover, a comprehensive understanding of the synthesis mechanism is induced by various saccharides. Glucose, a monosaccharide, not only possesses reducibility but also plays a crucial role in preparation of sulfur vacancies. Maltose is a disaccharide that can hydrolyze into glucose and fructose, both of which exhibit reducibility. On the contrary, dextrin is difficult to break down into fructose or glucose, and faces certain challenges in promoting the formation of 1T-MoS2. Importantly, 1T-MoS2 with 76 % purity obtained in our study exhibits exceptional electrochemical performance, demonstrating a high specific capacitance of 228.4 F g−1 at 2 A g−1 and maintaining a cycling stability of 97 % after 10,000 cycles. Furthermore, an asymmetric flexible supercapacitor device is assembled by 1T-MoS2 and active carbon on carbon cloths, which shows superior flexibility, high power density, and energy density. Notably, this work not only unveils the mechanism by which saccharides influence the synthesis of 1T-MoS2 but also provides support for the preparation of other metallic members in the transition metal dichalcogenides (TMDs) family.

All-Solid-State Flexible Asymmetric Supercapacitors Based on WS2/rGO/CNT Hybrid Electrodes and Polymer-Based Ionic Liquid Electrolytes

All-Solid-State Flexible Asymmetric Supercapacitors Based on WS₂/rGO/CNT Hybrid Electrodes and Polymer-Based Ionic Liquid Electrolytes

The construction of a flexible solid-state asymmetric supercapacitor device using nickel-copper oxide nanoplates and carbon nanosphere serving as positive and negative electrode, respectively with excellent electrochemical capabilities

Here, nickel-copper oxide nanoplates (NCN) and carbon nanosphere (CNS) as positive and negative electrodes are synthesised via a hydrothermal protocol without adding any surfactant and binders. The NCN and CNS electrodes in KOH electrolyte exhibit superior specific capacitance of ∼ 2362.5 F g−1 and ∼ 246.11 F g−1 at 1 A g−1 respectively. The NCN and CNS retained 98.54 % and 97.88 % of the initial capacitance after 3000 galvanostatic charge–discharge (GCD) cycles, respectively. Additionally, an asymmetric supercapacitor (ASC) device NCN//CNS is constructed using NCN and CNS as positive and negative electrodes, utilizing poly(vinyl alcohol) PVA − KOH gel electrolyte separator. The ASC device demonstrates a maximum energy density of 50.4 Wh kg−1 (181.44 KJ kg−1) with a power density ∼ 750 W kg−1 at 1 A g−1, maintaining 90.4 % cyclic stability after 10,000 GCD cycles. The electrochemical outputs of the device present significant potential for the advancement of high-performance ASC devices in electronic applications.

Assembly of manganese dioxide/polypyrrole electrode//activated carbon flexible asymmetric supercapacitor with excellent electrochemical performances

Manganese dioxide (MnO2) often suffers from a slow electron transport, and so improving the charge transport capability of MnO2 is imminent. In here, crossed MnO2 nanosheets grown on carbon cloth (CC) are fabricated firstly and subsequently coated with a layer of polypyrrole (PPy) to prepare CC/MnO2/PPy (CC/MP) electrode. At 1 A g−1, the prepared electrode is able to deliver a specific capacitance of 328 F g−1. The flexible asymmetric supercapacitor consists of CC/MP and CC/activated carbon (CC/AC) separately as positive and negative electrodes and PVA‐H2SO4 as gel electrolyte. The assembled device exhibits a specific capacitance of 123.96 F g−1 at 10 mV s−1, reaches a voltage window of 1.6 V, has a capacitance retention of 96.46% after 8000 cycles, and produces an energy density of 25.67 W h kg−1 at a power density of 401.79 W kg−1, as well as an energy density of 8.78 W h kg−1 at a power density of 3902.22 W kg−1. The two devices in series can illuminate 1.8 V red light‐emitting diode (LED) light. These excellent electrochemical properties are ascribed to the unique heterostructure of the electrode composite. The outcomes indicate that the prepared CC/MP electrode and the corresponding device have huge potential applications in next‐generation high‐performance supercapacitor devices.

Effect of fluoride (CoF2) based electrode material for high energy and power density asymmetric flexible supercapacitors

Herein, an asymmetric supercapacitor (ASC) device was assembled by employing the pristine CoF2 as active positive electrode material and activated carbon (AC) as negative electrode material. The CoF2 electrode exhibited an outstanding electrochemical behavior with enhanced specific capacitance (Cs) of 872 F/g at 1 A/g current density in three electrode configurations. The reversible Faradaic redox reactions in CoF2 instigate the formation of cobalt-oxyfluorides and generating the mixed valence state of Co (Co2+ and Co3+) which improves its electrical conductivity and electrochemical behaviors. Furthermore, the room temperature paramagnetic nature of CoF2 increases the gradient force of ions which could possibly increase the redox reactions at the electrolyte/electrode interface. The constructed asymmetric device structure of CoF2//AC revealed a quasi-rectangular shaped cyclic voltametric curve and symmetrical semi-triangular shaped galvanostatic charge-discharge profiles, respectively, which affirms the combined electric double layer capacitance and pseudocapacitive nature by its hybrid assembly. Hence, the constructed CoF2//AC ASC demonstrated a remarkable specific capacitance of 141 F/g, energy density of 44.06 Wh.Kg−1, and power density of 422.97 W.Kg−1 at 1 A/g with the high cell voltage of 1.5 V. The CoF2//AC ASC device retained c.a. 92 % of its initial capacitance and attained over 96 % of Coulombic efficiency after 2000 cycles of charge-discharge profiles at 1 A/g, which suggests the high electrochemical stability. This admirable electrochemical performance and the origin towards the magneto-capacitance of CoF2 could pave a new way to explore next generation high-performance supercapacitors.

Composite of CoS1.97 nanoparticles decorated CuS hollow cubes with rGO as thin film electrode for high-performance all solid flexible supercapacitors

Stretchable flexible thin-film electrodes are extensively explored for developing new wearable energy storage devices. However, traditional carbon-based materials used in such independent electrodes have limited practical applications owing to their low energy storage capacity and energy density. To address this, a unique structure and remarkable mechanical stability thin-film flexible positive electrode comprising CoS1.97 nanoparticles decorated hollow CuS cubes and reduced graphene oxide (rGO), hereinafter referred to as CCSrGO, is prepared. Transition metal sulfide CoS1.97 and CuS shows high energy density owing to the synergistic effects of its active components. The electrode can simultaneously meet the high-energy density and safety requirements of new wearable energy storage devices. The electrode has excellent electrochemical performance (1380 F/g at 1 A/g) and ideal capacitance retention (93.8 % after 10,000 cycles) owing to its unique three-dimensional hollow structure and polymetallic synergies between copper and cobalt elements, which are attributed to their different energy storage mechanisms. Furthermore, a flexible asymmetric supercapacitor (FASC) was constructed using CCSrGO as the positive electrode and rGO as the negative electrode (CCSrGO//rGO), which delivers an energy density of 100 Wh kg−1 and a corresponding power density of 2663 W kg−1 within a voltage window of 0–1.5 V. The resulting FASC can power a light-emitting diode (LED) at different bending and twisting angles, exerting little effect on the capacitance. Therefore, the prepared CCSrGO//rGO FASC devices show great application prospects in energy storage.

All-functionalized-graphene ribbon films for flexible asymmetric supercapacitors with ultrahigh energy and power densities

Asymmetric (hybrid) supercapacitors (ASCs) based on different positive and negative pseudocapacitance materials can deliver more energy density than electric double layer capacitors (EDLCs). Yet, few pseudocapacitive materials can provide high energy and power density, simultaneously, due to their poor conductivity and unfavorable reaction kinetics under fast charge/discharge rates. Here, we graft sulphur- and oxygen- functionalized into interconnected graphene ribbons to improve the accessibility of ion and enhance redox-active sites. The prepared sulphur- and oxygen- functionalized interconnected graphene ribbon (S-IGR and O-IGR) films as positive electrode and negative electrode, respectively, for high energy density flexible ASCs. Benefiting from the more “active sites” for the graphene ribbons, the S-IGR and O-IGR films connect more sulphur and oxygen groups. As a result, the S-IGR and O-IGR films exhibit ultra-high specific capacitance of 1660 F g−1 (1.66 F cm−2) and 428 F g−1 (0.43 F cm−2), respectively. More importantly, the assembled O-IGR//S-IGR ASCs based on aqueous and gel electrolytes exhibit ultra-high energy densities of 106.6 Wh kg−1 and 35.6 Wh kg−1, respectively. With the ultrafast charging and discharging capability, the ASCs based on aqueous electrolytes can be charge/discharged within 0.53 s to deliver high energy density of 15.0 Wh kg−1 and ultrahigh-power density of 101.4 kW kg−1. Thus, this strategy could possibly be used as designing and fabricating new generation of all grphene-based ASCs with high energy and power densities.

Flexible electrodes composed of flower-like MoS2 and MXene for supercapacitor applications

Flexible supercapacitors with high charge storage ability are needed for emerging applications in wearable electronics. Here, we introduce a novel flexible supercapacitor electrode by incorporating flower-like MoS2 into MXene via a hydrothermal technique. We mostly focused on the structural design for electrode configuration to enhance the charge storage mechanism. Three different electrodes composed of MoS2, MXene, and MoS2@MXene were fabricated via a versatile drop-casting and drying method. There are unique advantages of incorporating MoS2 with MXene such as the fast electron transfer, hydrophilicity of the interface, and structural stability. The MoS2@MXene // MXene flexible asymmetric supercapacitor device offered a high energy density of 1.21 W h /kg and a power density of 54.45 W /kg. Moreover, the asymmetric device exhibits nearly identical electrochemical behavior following 100 bending cycles at different angles. The high electrochemical activity of MoS2 and MXene and good interaction are ascribed to the superior electrochemical performance of the composite material. Furthermore, this research could guide the development of flexible, high-performance, and low-cost electrodes which will be useful in wearable electronics.

Constructing Hierarchical CoGa2O4-S@NiCo-LDH Core-Shell Heterostructures with Crystalline/Amorphous/Crystalline Heterointerfaces for Flexible Asymmetric Supercapacitors.

The rational design and construction of composite electrodes are crucial for overcoming the issues of poor working stability and slow ionic electron mobility of a single component. Nevertheless, it is a big challenge to construct core-shell heterostructures with crystalline/amorphous/crystalline heterointerfaces in straightforward and efficient methods. Here, we have successfully converted a portion of crystalline CoGa2O4 into the amorphous phase by employing a facile sulfidation process (denoted as CoGa2O4-S), followed by anchoring crystalline NiCo-layered double hydroxide (denoted as NiCo-LDH) nanoarrays onto hexagonal plates and nucleation points of CoGa2O4-S, synthesizing dual-type hexagonal and flower-like 3D CoGa2O4-S@NiCo-LDH core-shell heterostructures with crystalline/amorphous/crystalline heterointerfaces on carbon cloth. Furthermore, we further adjust the Ni/Co ratio in LDH, achieving precise and controllable core-shell heterostructures. Benefiting from the abundant crystalline/amorphous/crystalline heterointerfaces and synergistic effect among various components, the CoGa2O4-S@Ni2Co1-LDH electrode exhibits a specific capacity of 247.8 mAh·g-1 at 1 A·g-1 and good rate performance. A CoGa2O4-S@Ni2Co1-LDH//AC flexible asymmetric supercapacitor provides an energy density of 58.2 Wh·kg-1 at a power density of 850 W·kg-1 and exhibits an impressive capacitance retention of 105.7% after 10,000 cycles at 10 A·g-1. Our research provides profound insights into the design of other similar core-shell heterostructures.

Design of honeycomb-like WSe2@ZnS coated NH4NiPO4.H2O hybrids for flexible all-solid-state asymmetric supercapacitors

Supercapacitors are a commercially available form of energy storage that exhibit both the ability to store energy and a high rate of charging and discharging. All-solid-state flexible asymmetric supercapacitors (ASCs) have great potential for wearable electronic devices, and the reasonable design of electrode materials is a crucial step in their development. In this study, we demonstrated that NH4NiPO4.H2O can be merely hybridized with WSe2@ZnS. When compared to pure NH4NiPO4.H2O, the resulting NH4NiPO4.H2O@WSe2/ZnS composites demonstrate increased specific capacity of 1542 F g−1 at a current density of 1 A g−1and enhanced stability. Employing the Activated carbon on carbon cloth (AC//CC) as a negative electrode and a NH4NiPO4.H2O/WSe2@ZnS//CC as a positive electrode, and solid electrolyte PVA-KOH gel as both of the electrolyte and the separator, the fabricated all-solid-state flexible ASC can exhibit a specific capacity of 146 F g−1 at the current density of 1 A g−1, and a maximum energy density of 160.8 Wh kg−1 at a power density of 8.85 kW kg−1. More than 92 % of its initial capacity is still present in the ASC device after 10,000 cycles.

Flexible solid-state asymmetric supercapacitor based on reduced graphene oxide (rGO)/ruthenium oxide (RuO2) composite electrode

Energy storage in flexible supercapacitor devices extensively depends on electrode design with good electrochemical as well as mechanical properties. Here, a cost-effective and scalable method is proposed for the synthesis of a reduced graphene oxide/ruthenium oxide (rGO/RuO2) composite thin film for flexible supercapacitor. The successive ionic layer adsorption and reaction (SILAR) method used to synthesize rGO/RuO2 composite electrode allowed the synthesis of amorphous RuO2 with optimized rGO composition. The morphological structure of rGO/RuO2 composite examined using a scanning electron microscope showed compact spherical microparticles coated on rGO sheets. The electrochemical measurements of rGO/RuO2 composite electrode revealed that the composite material achieved a specific capacitance of 1371 F g−1 at a scan rate of 5 mV s−1. Due to the combined impact of rGO and RuO2, a flexible solid-state asymmetric supercapacitor (FSS-ASC) of configuration rGO/RuO2/PVA-H2SO4/WO3 exhibited Cs of 114 F g−1 at 5 mV s−1 with 88% of capacitance retention after 5000 galvanostatic charge-discharge (GCD) cycles. The FSS-ASC provided a remarkable specific energy of 23 Wh kg−1 and a specific power of 613 W kg−1. The electrochemical features of rGO/RuO2 composite show a promising way to fabricate flexible supercapacitors.

High-performance flexible asymmetric supercapacitors based on Hy-NiCoS/CNTs composites on porous graphene films

This research focused on the synthesized NiCoS/CNT composites by a hydrothermal method using thiourea and then drop-cast on laser-induced graphene (LIG) with porous structures for an active electrode of flexible asymmetric supercapacitors. Surface topography, cross-sectional outline, chemical structure and properties, and electrical properties of LIG, NiCoS, and Hy-NiCoS materials were measured and analyzed. In the two-electrode device, the Hy-NiCoS electrode has a high areal capacitance of 817 mF/cm2 under 0.5 mA/cm2 current density and a low internal resistance of 5.19 Ω. Furthermore, the prepared flexible asymmetric supercapacitors (Hy-NiCoS/AC) demonstrated excellent energy density of 0.017 mWh/cm2, power density of 3.2 mW/cm2, and areal capacitance of 85 mF/cm2 under 0.5 mA/cm2 current density. When the bending angles were 0°, 45°, and 90°, the areal capacitances of the prepared flexible asymmetric supercapacitors were 77.7, 75.0, and 70.8 mF/cm2, respectively. There is no obvious capacitance decay even at a large bending angle of 90°, which means that the asymmetric supercapacitor has excellent flexibility and stability. Based on the flexible asymmetric supercapacitors with excellent electrochemical performance, the proposed supercapacitors can be widely used in wearable electronic devices and healthcare products.

PH-Regulated host-guest architecture in molybdenum Dioxide/Carbon sphere composites for flexible solid-state supercapacitors

Compositing molybdenum dioxide (MoO2) with carbon sphere (CS) can greatly enhance the conductivity and structural instability to achieve its high theoretical capacitances. The controllable regulation of local architecture and host–guest interaction in the two-phase composites is highly desirable, but commonly hindered by the significant difference in formation mechanism between MoO2 and CS. Herein, a pH-regulated pre-intervention strategy was developed to provide control over the MoO2/CS architecture by adjusting the interplay between the precipitation kinetics of MoO2 and the polymerization effect of hydrochar precursor. By varying the pre-synthesis pH from 10.0 to 0.1, the corresponding dominant formation process of precursor changes from inside-out Ostwald ripening to protonation-induced electrostatic interactions, resulting in the structural evolution of MoO2/CS from hollow CS-encapsulating MoO2 nanosheets and solid CS-supporting MoO2 nanoparticles. The electrochemical test proved the former architecture possesses faster electrode kinetics, lower charge/ion-transfer resistance, and better electrochemical stability. An extended oxidation-etching method was further introduced to prepare mesoporous CS with excellent supercapacitive properties. A flexible solid-state asymmetric supercapacitor composed of optimal MoO2/CS structure as the positive electrode and mesoporous CS as the negative electrode delivers a high energy density of 52.3 W h kg−1 and power density of 14500 W kg−1, and good cycling stability with 89.7 % retention of the initial capacitance after 8000 cycles.

In situ growth of binder-free CoNi0.5-MOF/CC electrode for high-performance flexible solid-state supercapacitor application.

Metal organic frameworks (MOFs) with binder-free electrodes have shown promise for portable electrochemical energy storage applications. However, their low specific capacitance and challenges associated with the attachment of active materials to the substrate constrain their practical utility. In this research, we prepared a CoNi0.5-MOF/CC electrode by in situ growth of CoNi0.5-MOF on an H2O2-pretreated carbon cloth (CC) without using any binder. It exhibits a higher specific capacitance of 1337.5 F g-1 than that of CoNi0.5-MOF (∼578 F g-1) at a current density of 1 A g-1 and an excellent rate ability of 88% specific capacitance retention at a current density of 10 A g-1 after 6000 cycles. The as-assembled flexible asymmetric solid-state supercapacitor based on the CoNi0.5-MOF/CC positive electrode and a nitrogen-doped graphene (N-Gr) negative electrode exhibits an energy density of 61.46 W h kg-1 at a power density of 1244.56 W kg-1 and holds a stable capacitance of ∼125 F g-1 at 1 A g-1 when the flexible supercapacitor is bent, showing great potential for flexible electronics application. The H2O2 is indicated to play an important role, enhancing the adhesion of CoNi0.5-MOF on CC and reducing its charge transfer resistance by functionalizing the carbon fiber during the pretreatment of the CC matrix. The results provide a great way to prepare a flexible asymmetric solid-state supercapacitor with both high power density and high energy density for practical application.

Construction of a binder-free PANI-CQD-Cu electrode via an electrochemical method for flexible supercapacitor applications.

In recent years, flexible hybrid supercapacitors (FSCs) have played a significant role in energy storage applications owing to their superior flexibility and electrochemical properties. In this study, carbon quantum dots (CQDs) were prepared from ascorbic acid via a hydrothermal method and physical and chemical characterizations were performed. Then, the carbon quantum dots (CQDs) were doped with polyaniline (PANI) and copper (Cu) to form a PANI-CQD-Cu composite coated on carbon cloth (CC) using an electropolymerization method. In the polymerization process, CQDs bind with the PANI chain and form a PANI-CQD-Cu composite. The prepared electrode's functional group and surface morphology were characterized through XRD, Raman, BET, XPS and SEM with EDAX studies. The electrochemical properties of the PANI-CQD-Cu electrode were investigated using cyclic voltammetry, impedance spectroscopy and galvanostatic charge-discharge study. The capacitance value of PANI-CQD-Cu was 1070 mF cm-2 at 5 mA cm-2 (1070 F g-1 at 1 A g-1), which was higher than that of PANI (775 mF cm-2). Moreover, a flexible asymmetric supercapacitor (FASC) based on an activated carbon/PVA-H2SO4/PANI-CQD-Cu device was fabricated, which exhibited outstanding energy and power densities of 23.10 μW h cm-2 and 0.978 mW cm-2, respectively. The capacitance value remained at 92% after 3000 cycles. The outcome results indicated that the PANI-CQD-Cu-coated CC electrode material can be a promising electrode material for practical energy storage applications.

High-performance flexible solid-state asymmetric supercapacitor with NiCo2S4 as a cathode and a MXene-reduced graphene oxide sponge as an anode

Ti3C2 MXenes have revealed immense potential in energy storage systems.

In situ growth of a redox-active metal-organic framework on electrospun carbon nanofibers as a free-standing electrode for flexible energy storage devices.

The rational construction of free-standing and flexible electrodes for application in electrochemical energy storage devices and next-generation supercapacitors is an emerging research focus. Herein, we prepared a redox-active ferrocene dicarboxylic acid (Fc)-based nickel metal-organic framework (MOF) on electrospun carbon nanofibers (NiFc-MOF@CNFs) via an in situ approach. This in situ approach avoided the aggregation of the MOF. The NiFc-MOF@CNF flexible electrode showed a high redox-active behavior owing to the presence of ferrocene and flexible carbon nanofibers, which led to unique properties, including high flexibility and lightweight. Furthermore, the prepared electrode was utilized in a supercapacitors (SC) without the use of any binder, which achieved a specific capacity of 460 C g-1 at 1 A g-1 with an excellent cyclic retention of 82.2% after 25 000 cycles and a good rate capability. A flexible asymmetric supercapacitor device was assembled, which delivered a high energy density of 56.25 W h kg-1 and a long-lasting cycling performance. Also, the prepared electrode could be used as a freestanding electrode in flexible devices at different bending angles. The obtained cyclic voltammetry curves showed negligible changes, indicating the high stability and good flexibility of the electrode. Thus, the use of the in situ strategy can lead to the uniform growth of redox-active MOFs or other porous materials on CNFs.

Li Salt Assisted Highly Flexible Carbonaceous Ni3N@polyimide Electrode for an Efficient Asymmetric Supercapacitor.

This work used a highly flexible, sustainable polyimide tape as a substrate to deposit ductile-natured carbonaceous Ni3N (C/Ni3N@polyimide) material for supercapacitor application. C/Ni3N was prepared using a co-sputtering technique, and this method also provided better adhesion of the electrode material over the substrate, which is helpful in improving bending performance. The ductile behavior of the sputter-grown electrode and the high flexibility of the polyimide tape provide ultimate flexibility to the C/Ni3N@polyimide-based supercapacitor. To achieve optimum electrochemical performance, a series of electrochemical tests were done in the presence of various electrolytes. Further, a flexible asymmetric supercapacitor (NC-FSC) (C/Ni3N//carbon@polyimide) was assembled by using C/Ni3N as a cathode and a carbon thin film as an anode, separated by a GF/C-glass microfiber soaked in optimized 1 M Li2SO4 aqueous electrolyte. The NC-FSC offers a capacitance of 324 mF cm-2 with a high areal energy density of 115.26 μWh cm-2 and a power density of 811 μW cm-2, with ideal bending performance.

Biomass Derived Flexible Free-Standing Electrodes for a High Performance Supercapacitor

Global energy demand, the depletion of fossil fuels, and environmental deterioration have spurred a search for significant improvements in energy conversion and storage. The need for efficient methods of electrical energy storage for on-demand use is critical. Batteries and supercapacitors (SCs) are two of the main energy-storing technologies. SCs and batteries are frequently used in everyday items like smartphones, wearable electronics, electric cars, and portable electronic devices. Supercapacitors (SCs) continue to generate a lot of attention due to their higher energy storage capacity than conventional capacitors and faster rate performance than rechargeable batteries. Supercapacitors, on the other hand, have a high-power density (>10 kWkg-1), extended cycle stability, and an increased capacity for charging and discharging quickly. Supercapacitors are divided into two major categories: EDLC and pseudo-capacitors, depending on the charge storage mechanism. At the electrode-electrolyte contact in EDLC, a double layer of charge is created. Charge transfer reactions between the electrode and electrolyte cause pseudo-capacitance to arise. Compared to EDLCs, pseudocapacitive materials have a greater capacitance. Materials that are pseudo-capacitative include transition metal oxides (TMOs) like, Fe2O3, CoO, NiO, ZnO2, TiO2, and V2O5. which are good candidates for high-performance supercapacitors. Herein, we have proposed a pseudocapacitive material functionalized carbon fabrics produced from cellulosic-based biomass material as a free-standing electrode for supercapacitor application. The fibrous electrode not only provides good mechanical flexibility but also a large surface area for electron transportation in the charging-discharging process. An excellent specific capacitance of ~ 1024 Fg-1 was exhibited in the three-electrode system. An electrochemical study for a full-cell asymmetric supercapacitor was also carried out which showed that the electrodes have an appreciable energy density of ~ 32 Wh kg-1 at a power density of ~ 120 W kg-1. In addition, a flexible asymmetric supercapacitor was also fabricated. A specific capacitance of ~ 40 Fg-1 was achieved in the device. Also, after bending at different angles there was no change in the cyclic voltammetric curve, suggesting that functionalized carbon fabric has good flexibility. Keywords : Supercapacitor, Cellulosic material, Free-standing, Carbon fibre