Flexible Supercapacitor Applications Research Articles

ZnCl2 activated Tomato waste derived porous carbon material for high power density for flexible supercapacitor applications

ZnCl2 activated Tomato waste derived porous carbon material for high power density for flexible supercapacitor applications

Rapid and Facile Method for the Synthesis of a Nanoarray Hierarchical Composite and Its Application in Flexible Self-Chargeable Supercapacitors

Rapid and Facile Method for the Synthesis of a Nanoarray Hierarchical Composite and Its Application in Flexible Self-Chargeable Supercapacitors

Interfacial-engineered robust and high performance flexible polylactic acid/polyaniline/MXene electrodes for high-perfarmance supercapacitors

Flexible supercapacitors with high mechanical strength, excellent flexibility, and high performance are highly desired to meet the increasing demands of flexible electronics. However, the trade-off between mechanical and electrochemical properties remains challenging. In this context, an interface-engineered strategy approach was proposed to construct polylactic acid (PLA)/polyaniline (PANI)/MXene (PPM) film electrodes for flexible supercapacitor applications. In the PPM electrode, the porous PLA prepared from the nonsolvent-induced-phase-separation method served as an ideal flexible substrate, providing excellent flexibility and high mechanical strength, whereas PANI as the coupling agent, enhanced the interfacial strength between PLA and the electroactive MXene that was firmly anchored and deposited on PLA through a facile layer-by-layer dip coating method. The tensile strength at break, elongation at break, and toughness of PPM are 53.09 MPa, 11.09 %, and 4.12 MJ/m3, respectively, much higher than those of pure MXene (29.36 MPa, 4.62 %, and 0.75 MJ/m3). At an optimum mass loading density of 3 mg cm−2 for MXene, the fabricated PPM3 film electrode achieved a high specific capacitance of 290.8 F g−1 at a current density of 1 A g−1 in the three-electrode setup, approximately 1.5 times that of 190.8 F g−1 for pure MXene. Meanwhile, the symmetric all-solid-state supercapacitor based on PPM3 film electrodes delivers a high specific capacitance of 193.7 F g−1 at a current density of 0.25 A g−1, with a corresponding high energy density of 9.3 Wh kg−1 at a power density of 291.3 W kg−1. The SC retains 86 % of its original capacitance even bent at 120° and also possesses an excellent fire-retardant ability, demonstrating its great potential for flexible and safe wearable electronics.

Graphene nanoribbons on three-dimensional carbon nanomaterials for high-performance flexible zinc-ion hybrid supercapacitors

The rational design of electrodes is crucial for the performance and practical applications of flexible zinc-ion hybrid supercapacitors (ZIHS). In this paper, we have developed an easy strategy to design electrodes based on current collectors with vertically aligned nanohole arrays on their surfaces. Zinc nanosheet arrays were deposited on a porous aluminum oxide/aluminum (AAO) film to form a Zn@AAO anode. Graphene nanoribbons (GR) unzipped for carbon nanotubes were coated on a unique three-dimensional carbon pre-coated AAO (CAAO) film to form a GR@CAAO composite cathode. After assembling with ZnSO4/gelatin gel electrolyte, a quasi-solid Zn@AAO//GR@CAAO ZIHS with a potential of 1.6 V was obtained. The as-prepared ZIHS exhibits an areal capacitance of 156 mF cm−2 at 0.25 mA cm−2 and a high energy density of 56 μW h cm−2 at 0.202 mW cm−2, an excellent flexibility as well as long cycle life.

Mn-Ni-based coating on flexible graphite fiber with high length capacitance for flexible supercapacitor applications

Significant growth has been observed in the development of technologies that employ flexible displays and sensors; however, the progress made in the realm of flexible energy storage devices has been relatively limited. Because flexibility and stretchability are critical for wearable, biomedical, and portable electronic devices, flexible energy storage electrodes must be researched. In this work, electrochemical behaviors of alloy-coated graphite fibers having flexibility have been investigated. Mn-Ni-based modified graphite was obtained electrochemically from a deep eutectic solvent ionic liquid at a different static voltage. The electrochemical deposition performance of films in Ethaline deep eutectic solvent and cycling of the resulting electrodes in a KOH electrolyte were analyzed using a potential window of 0.7 V. Fabricated flexible electrodes were characterized via the SEM, EDX, FTIR, and XRD techniques to reveal their morphological, compositional, and structural properties. Length capacitance, charge-discharge and self-discharge behaviors of fabricated flexible electrodes were calculated. The performance of the electrode can be controlled by modifying the material structure through changes in the deposition conditions. The graphite fiber coated with MnNi by application of −1.75 V had a length capacitance of 40.3 mF cm−1. The film had high surface coverage and could potentially be suitable for energy storage purposes. It is possible to create stretchable electrodes for wearable electronics by knitting graphite fibers covered with metals or alloys.

In situ-fabricated quasi-solid polymer electrolytes incorporating an ionic liquid for flexible supercapacitors

A quasi-solid polymer electrolyte is fabricated by an in situ polymerization of PEGDMA in AN solvent based on a thermal initiation mechanism and incorporating the ionic liquid EMITFSI for application in flexible supercapacitors.

The effect of zinc and sodium borate doping on the structural, morphological, optical, electrical and electrochemical properties of PEDOT:PSS thin film electrodes for flexible and transparent supercapacitor applications

In this study, for the first time, we propose new electrode materials for transparent and flexible supercapacitors by doping sodium borate (NaB) and zinc borate (ZnB) to poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS).

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.

Lead-free halide perovskites for high-performance thin-film flexible supercapacitor applications

The growing interest in smart portable electronic devices demands a flexible and lightweight power supply.

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.

Plastic wastes-derived electro-spun nanofiber/MnO2 nanocomposite for flexible supercapacitor application

The usage of plastic bottles in large quantities will cause serious pollution to the environment due to its poor biodegradability. The recycling of plastic waste with high added value for expanded applications needs to be explored and the poor mechanical properties should be resolved at the meantime. Herein, plastic waste was recycled into flexible nanofiber electrode based on electrospinning associated with acidified carbon nanotubes loaded inside/outside and electrodeposition of nano-MnO2 film outside. The fabricated plastic waste-based composites could be directly used as a supportable electrode with high conductivity, multistage aperture structure and efficient pseudo-capacitance. And the further assembled symmetric supercapacitors exhibited excellent flexibility, high energy capacity as the specific capacitance of 118.8 mF/cm2 at a scan rate of 10 mV/s and desirable cycle stability as 97.6 % capacitance retention over 5000 charge/discharge cycles. The strategies presented herein help alleviate the white pollution problem and realize the recycling and utilization of waste plastic products with high added value, which is a cost-effective and sustainable option to promote circular economy.

Recent Progress and Prospects of MXene/Cellulose‐Based Composite Electrodes: A Sustainable Pathway towards Supercapacitor Application

AbstractMXenes, a group of two‐dimensional (2D) metal carbides and nitrides, have emerged as promising electrode materials for supercapacitors. This is primarily attributed to their inherent metal‐like electrical conductivity, layered structure, surface redox reactivity, and superior pseudocapacitance through surface functional groups. Owing to its promising features, this material suffers from low mechanical strength, restacking, and unprecedented oxidation. As a result, balancing the electrochemical performance becomes challenging, eventually impeding its potential applications in lightweight, flexible supercapacitor applications. Recent strategies are centered on lighter and more stable filler materials to tackle these issues. Among these, cellulose is considered one of the most effective renewable materials because of its biocompatibility, thermal stability, high surface area, and mechanical reinforcement. Moreover, nanocellulose is capable of hosting other functional materials on its reactive surfaces, ensuring better ion accessibility, and can be used as an electrolyte separator membrane. This review paper aims to provide a comprehensive overview of recent advances in the fabrication strategy, deterministic parameters for capacitive energy‐storage devices, electrochemical behavior, and the performance of MXene/cellulose‐based electrodes in its three‐dimensional aspect (1D, 2D and 3D) for supercapacitor application. Lastly, this review will outline the challenges and prospects of MXene/cellulose‐based composite electrodes in real‐life supercapacitor applications.

Pseudocapacitive Storage in Molybdenum Oxynitride Nanostructures Reactively Sputtered on Stainless-Steel Mesh Towards an All-Solid-State Flexible Supercapacitor.

Exploiting pseudocapacitance in rationally engineered nanomaterials offers greater energy storage capacities at faster rates. The present research reports a high-performance Molybdenum Oxynitride (MoON) nanostructured material deposited directly over stainless-steel mesh (SSM) via reactive magnetron sputtering technique for flexible symmetric supercapacitor (FSSC) application. The MoON/SSM flexible electrode manifests remarkable Na+-ion pseudocapacitive kinetics, delivering exceptional ≈881.83Fg-1 capacitance, thanks to the synergistically coupled interfaces and junctions between nanostructures of Mo2N, MoO2, and MoO3 co-existing phases, resulting in enhanced specific surface area, increased electroactive sites, improved ionic and electronic conductivity. Employing 3D Bode plots, b-value, and Dunn's analysis, a comprehensive insight into the charge-storage mechanism has been presented, revealing the superiority of surface-controlled capacitive and pseudocapacitive kinetics. Utilizing PVA-Na2SO4 gel electrolyte, the assembled all-solid-state FSSC (MoON/SSM||MoON/SSM) exhibits impressive cell capacitance of 30.7mFcm-2 (438.59Fg-1) at 0.125mAcm-2. Moreover, the FSSC device outputs a superior energy density of 4.26µWhcm-2 (60.92Whkg-1) and high power density of 2.5mWcm-2 (35.71kWkg-1). The device manifests remarkable flexibility and excellent electrochemical cyclability of ≈91.94% over 10,000 continuous charge-discharge cycles. These intriguing pseudocapacitive performances combined with lightweight, cost-effective, industry-feasible, and environmentally sustainable attributes make the present MoON-based FSSC a potential candidate for energy-storage applications in flexible electronics.

In-situ Mg-Al LDH infused lignin-derived laser scribed graphene for facilitated ion transport in flexible supercapacitor application

BackgroundInnovations in the synthesis of hybrid materials have led to technology advancement of the microsupercapacitor. Delaminated layered double hydroxide (LDH) reduces self-agglomeration and increases energy density in graphene-based supercapacitors. The incorporation of delaminated LDH with oil palm lignin derived laser scribed graphene in neutral PAAS/K2SO4 gel electrolyte for flexible microsupercapacitor applications was investigated. MethodVarious concentrations of positively charged sucrose-delaminated Mg-Al LDH nanosheets produced through the coprecipitation method were hybridised with negatively charged oil palm lignin-derived laser scribed graphene (L-LSG) through electrostatic interaction. Significant FindingsHybrid laser scribed graphene developed from delaminated Mg-Al LDH at a concentration of 10 gL−1 (L-LSG/D-MgAl-10) had the largest surface area of 49.335 m2g−1. The incorporation of Mg-Al LDH nanosheets on l-LSG were further validated by FESEM, TEM, XRD, Zeta potential and other characterizations. It also had the highest areal capacitance and energy density, measuring 40 mFcm−2 and 0.00296 mWhcm−2, respectively, at a current density of 0.08 mAcm−2. The fabricated microsupercapacitor has exceptional bending capabilities and capacitance retention of 89.2% after 5000 cycles. In summary, by inducing additional pseudocapacitance, delaminated Mg-Al LDH improved the overall effectiveness of the oil palm lignin derived graphene electrode compared to pristine graphene.

Strategies in the preparation of conductive polyvinyl alcohol hydrogels for applications in flexible strain sensors, flexible supercapacitors, and triboelectric nanogenerator sensors: an overview

Strategies in the preparation of conductive polyvinyl alcohol hydrogels for applications in flexible strain sensors, flexible supercapacitors, and triboelectric nanogenerator sensors: an overview

Fabrication of flexible nitrogen and phosphorus-codoped porous carbon membrane and investigation of capacitance performance

Porous carbon materials have been used extensively in new energy storage materials. They have the advantages of high stability, large specific surface area, and good electrical conductivity. However, carbon material capacitance still needs to be increased. In this paper, nitrogen and phosphorus-codoped porous carbon membrane (NPCM) was prepared by electrostatic spinning using polyacrylonitrile (PAN) as a carbon and nitrogen source, triphenylphosphine (TPP) as a phosphorus source and SBA-15 as a templating agent. When PAN/TPP was set to 2:1, the resulting NPCM has good flexibility, with N and P doping content of 13.8% and 0.5%, respectively, and a specific surface area of 872 m2/g. The NPCM was used as the working electrode with 1.0 M H2SO4 electrolyte and a specific capacitance of 215 F/g was achieved at a current density of 0.5 A/g by a three-electrode test, The capacitance retention rate could reach 103% after 1000 charge/discharge cycles at a current density of 2.0 A/g. Therefore, these results indicate that NPCM has great potential for application in high-performance flexible supercapacitors.

Construction and electrochemical properties of carbon nanotube composite Mn-MOFs materials electrode for high-performance flexible supercapacitors

Metal organic frameworks (MOFs) as electrode materials for supercapacitors have attracted extensive attention due to their porous structure. However, the poor conductivity of MOFs limits the charge transfer. In this work, Mn-MOF/carbon nanotube (CNT) composites were grown directly on carbon cloth (CC) in one step by the traditional hydrothermal synthesis of MOFs to improve the electrical conductivity of Mn-MOFs. The structural and performance tests show that CNTs, as a conductive backbone, can connect Mn-MOFs to each other, which can obviously solve the problem of poor conductivity of MOF materials. The Mn-MOFs/CNTs/CC electrodes show a larger specific capacitance and excellent cycling stability by electrochemical tests. Compared to the original Mn-MOF electrode, the surface capacitance obtained increases from 188.8 mF·cm−2 to 385.8 mF·cm−2 at a current density of 0.8 mA·cm−2 and maintains a high capacitance retention of 118% after 5000 charge/discharge cycles at a current density of 5 mA·cm−2. This work confirms that the in- situ synthesis of MOFs and CNTs has promising applications in fabric-based flexible supercapacitors.

Facial synthesis of reduced graphene oxide – Amorphous nickel tungstate composite for flexible hybrid asymmetric solid state supercapacitor application

Supercapacitors are crucial as an additional type of energy storage device assisting various types of energy storage systems for high power requirement. Herein, using successive ionic layer adsorption and reaction (SILAR) method, thin films of reduced graphene oxide (rGO) composited with nickel tungstate (NiWO4) were synthesized with different rGO content. The synthesized material showed spherical morphology with rGO sheets and a specific surface area in the range of 85 to 107 m2 g−1. The three-electrode method was used, and the electrochemical performance of rGO-NiWO4 films was assessed in 2 M KOH electrolyte. A composite film deposited at 12 mg mL−1 concentration of rGO (CNW3) film exhibited a specific capacitance of 779 F g−1 at a current density of 2 A g−1. At a current density of 4 A g−1, CNW3 film showed outstanding electrochemical stability with 95 % capacitance retention after 5000 galvanostatic charge-discharge (GCD) cycles. This study emphasizes the usage of rGO-NiWO4 (CNW3) thin films deposited using SILAR method as a cathode in solid-state asymmetric supercapacitors (ASC). The rGO-NiWO4/PVA-KOH/AC ASC device exhibited a specific capacitance of 94.2 F g−1 at 5 A g−1, a specific energy of 33.5 Wh kg−1 and a specific power of 12.37 kW kg−1 with 83 % capacitance retention after 5000 GCD cycles. This suggests that rGO-NiWO4 thin film produced using SILAR method is a suitable candidate for supercapacitors.

Mussel‐Inspired Conductive Hydrogel with Enhanced Adhesion and Toughness in All‐Hydrogel Supercapacitors

AbstractHydrogels that combine electrical conductivity, mechanical and self‐adhesion properties have attracted considerable interest because of their promising applications in wearable devices and flexible supercapacitors, among others. However, the weak interfacial adhesion between adjacent layers of flexible supercapacitors limits their practical applications. In this work, mussel‐inspired nanocomposite hydrogels composed of tannic acid (TA)‐modified doped polyaniline (PANI) and functional monomer acrylamide (AAm) were prepared, the hydrogel exhibited good mechanical properties (903 % strain at break) and adhesion properties. In a three‐electrode system the hydrogel exhibited a specific capacitance of 851.1 mF cm−2 (at 1 mA cm−2) and good stability. All‐hydrogel supercapacitors with robust interfacial capabilities were assembled on this basis without additional immobilization. The flexible supercapacitors show favorable electrochemical performance (570 mF cm−3 at 1 mA cm−2) and provide a volume energy density 55.9 μWh cm−3 and a capacitance retention of 85.6 % after 2000 cycles. Compared with previous conductive hydrogels, this work will provide a new approach to fabricate nanocomposite hydrogels with self‐adhesive, robust mechanical properties and conductive performance, effectively improving the interfacial adhesion of integrated supercapacitors and expanding the application scope of flexible supercapacitors.

Scalable Solution Phase Synthesis of 2D Siloxene via a Two-Step Interlayer Expansion Process.

Two-dimensional (2D) siloxene is attracting considerable research interest recently principally owing to its inherent compatibility with silicon-based semiconductor technology. -The synthesis of siloxene has been mostly limited to multilayered structures using traditional topochemical reaction procedures. Herein, we report high-yield synthesis of single to few-layer siloxene nanosheets by developing a two-step interlayer expansion and subsequent liquid phase exfoliation procedure. Our protocol enables high-yield production of few-layer siloxene nanosheets with a lateral dimension of up to 4 μm and thickness ranging from 0.8 to 4.8 nm, corresponding to single to a few layers, well stabilized in water. The atomically flat nature of exfoliated siloxene can be exploited for the construction of 2D/2D heterostructure membranes via typical solution processing. We demonstrate highly ordered graphene/siloxene heterostructure films with synergistic mechanical and electrical properties, which deliver noticeably high device capacitance when assembled into a coin cell symmetric supercapacitor device structures. Additionally, we demonstrate that the mechanically flexible exfoliated siloxene-graphene heterostructure enables its direct use in flexible and wearable supercapacitor applications.