In Situ Growth of the Ni3V2O8@PANI Composite Electrode for Flexible and Transparent Symmetric Supercapacitors

Conductive MXene/Polymer Composites for Transparent Flexible Supercapacitors

Transparent flexible energy storage devices are limited by the trade-off among flexibility, transparency, and charge storage capability of their electrode materials. Conductive polymers are intrinsically flexible, but limited by small capacitance. Pseudocapacitive MXene provides high capacitance, yet their opaque and brittle nature hinders their flexibility and transparency. Herein, the development of synergistically interacting conductive polymer Ti3C2Tx MXene/PEDOT:PSS composites is reported for transparent flexible all-solid-state supercapacitors, with an outstanding areal capacitance of 3.1 mF cm-2, a high optical transparency of 61.6%, and excellent flexibility and durability. The high capacitance and high transparency of the devices stem from the uniform and thorough blending of PEDOT:PSS and Ti3C2Tx, which is associated with the formation of O─H…O H-bonds in the composites. The conductive MXene/polymer composite electrodes demonstrate a rational means to achieve high-capacity, transparent and flexible supercapacitors in an easy and scalable manner.

Smart Energy Storage: W18O49 NW/Ti3C2Tx Composite-Enabled All Solid State Flexible Electrochromic Supercapacitors

Developing a highly efficient electrochromic energy storage device with sufficient color fluctuation and significant electrochemical performance is highly desirable for practical energy-saving applications. Here, to achieve a highly stable material with a large electrochemical storage capacity, a W18O49 NW/Ti3C2Tx composite has been fabricated and deposited on a pre-assembled Ag and W18O49 NW conductive network by Langmuir-Blodgett technique. The resulting hybrid electrode composed of 15 layers of W18O49 NW/Ti3C2Tx composite exhibits an areal capacitance of 125 mF cm-2, with a fast and reversible switching response. An optical modulation of 98.2% can be maintained at a current density of 5 mA cm-2. Using this electrode, a bifunctional symmetric electrochromic supercapacitor device having an energy density of 10.26 µWh cm-2 and a power density of 0.605 mW cm-2 is fabricated, with high capacity retention and full columbic efficiency over 4000 charge-discharge cycles. Meanwhile, the device displays remarkable electrochromic characteristics, including fast switching time (5 s for coloring and 7 s for bleaching), and a significant coloration efficiency of 116 cm2 C-1 with good optical modulation stability. In addition, the device exhibits significant mechanical flexibility and fast switching while being stable over 100 bending cycles, which is promising for real-world applications.

Harnessing morphological alteration from microflowers to nanoparticles and cations synergy (Co:Ni) in binder-free cobalt nickel vanadate thin film cathodes synthesized via SILAR method for hybrid supercapacitor devices

Electrode materials must be rationally designed with morphologies and electroactive sites manipulated through cations' synergy in bimetal compounds in order to maximize the performance of energy storage devices. Therefore, the present study emphasizes binder-free scalable preparation of cobalt nickel vanadate (CNV) thin films by a facile successive ionic layer adsorption and reaction (SILAR) approach with specific cations (Co:Ni) alternation. Increasing the Ni cation content in the CNV notably transforms its microflower structure comprising nanoflakes (252 nm) into nanoparticles (74 nm). An optimized S-CNV5 thin film cathode with Co:Ni molar ratio of ∼ 0.4:0.6 and a high specific surface area of 340 m2 g-1, provided the excellent specific capacitance (Csp) and capacity (Csc) of 1382 F g-1 and 691 C g-1, respectively at 1 A g-1 current density. A hybrid aqueous supercapacitor (HASc) device with positive and negative electrodes comprising optimized CNV and reduced graphene oxide (rGO), respectively, in a 1 M KOH electrolyte delivered a Csp of 133 F g-1 and a specific energy (SE) of 53 Wh kg-1 at a specific power (SP) of 2261 kW kg-1. Additionally, a fabricated hybrid solid-state supercapacitor (HSSc) device with the same electrodes applying PVA-KOH gel electrolyte displayed a Csp of 119 F g-1, and SE of 46 Wh kg-1 at SP of 1184 W kg-1. This boosted electrochemical activity is due to the synergetic effects of Ni and Co species in the CNV thin film electrodes, emphasizing the potential of CNV electrodes as cathodes in hybrid energy storage devices.

Hollow Bowl NiS2 @polyaniline Conductive Linker/Graphene Conductive Network: A Triple Composite for High-Performance Supercapacitor Applications

The achievement of the outstanding theoretical capacitance of nickel sulfide (NiS2 ) is challenging due to its low conductivity, slow electrochemical kinetics, and poor structural stability. In this study, we utilize polyaniline (PANI) as a linker to anchor the NiS2 with a hollow bowl-like structure, uniformly dispersed at the surface of graphene oxide (GO)(NiS2 @15PG). The presence of PANI provides growth sites, resulting in a uniform and dense arrangement of NiS2 . This morphological modulation of NiS2 increases the contact area between the active material to electrolyte. Additionally, PANI effectively connects NiS2 with the conductive network of GO, which advances the electrical conductivity and ion diffusion properties. As a result, the Rct (charge transfer resistance) and Zw (Warburg impedance) of NiS2 @15PG decrease by 82.61 % and 66.76 % respectively. This unique structure confers NiS2 @15PG with high specific capacitance (536.13 C g-1 at 1 A g-1 ) and excellent multiplicative property of 60.93 % at 20 A g-1 . The assembled NiS2 @15PG//YP-50 supercapacitors (HSC) demonstrates an energy density (13.09 Wh kg-1 ) at a high-power density (16 kW kg-1 ). The capacity retention after 10,000 cycles at 5 A g-1 is 86.59 %, indicating its significant potential for practical applications.

Performance analysis of three distinct NixV2Oy single-phase nano self-assemblies for asymmetric supercapacitor fabrication and effective detection of low-concentration hazardous herbicide

Single-phase inorganic nanostructures with multiple applications are required for cost-effective, sustainable applications to save the environment from toxic activities. Nickel vanadate (NixV2Oy), possessing three phases, such as NiV2O6, Ni2V2O7, and Ni3V2O8, acts as an effective electrode material and potential electrochemical sensors. Nickel vanadate phases (NiV2O6, Ni2V2O7, and Ni3V2O8) were synthesized through the gel-matrix technique, and their phase purity, crystallinity, morphology, optical properties, etc., were evaluated and studied. Electrochemical studies infer that NiV2O6 exhibits the highest specific capacity of 251 C g-1 (69.7 mA h g-1) at 1 A g-1 compared to the other nickel vanadate phases and provides better cyclic stability of 80.19% for 5000 cycles. The asymmetric supercapacitor device fabricated from NiV2O6 results in a specific capacity of 189 C g-1 (52.5 mA h g-1), energy density of 59.06 W h kg-1, and a power density of 1125 W kg-1 with a capacitive retention rate of 74.91% and coulombic efficiency of 99.61% for 10 000 cycles. The electrochemical detection potential of NixV2Oy in bifenox herbicide has been studied with all the synthesized nanostructures. Among them, NiV2O6-based sensor probes demonstrated excellent characteristics, including high sensing current and low detection limits of 0.6 nM with a linear range of 1-57 nM. The real-time herbicide detection of NiV2O6 in live samples was checked with freshly harvested potatoes. This advancement further enhances the utilization of NixV2Oy materials for electrochemical applications.

Co-containing metal-organic framework for high-performance asymmetric supercapacitors with functionalized reduced graphene oxide

Nowadays, supercapacitors are the most coveted eco-friendly and sustainable next-generation energy storage devices. In this regard, developing supercapacitors with high energy density and power density has always been a challenge for researchers. Herein, we have exploited an electroactive Co-containing metal-organic framework (Co-MOF) using cheap and commercially available starting materials under refluxing conditions and explored its energy storage properties in three- and two-electrode methods. The Co-MOF exhibited a specific capacitance of 425 F g-1 at 2 A g-1, maintaining a capacitance of ∼78% over 2200 successive charge-discharge cycles in a three-electrode system. The two-electrode asymmetric supercapacitor (ASC) using Co-MOF as the working electrode and as-synthesized p-phenylenediamine (PPD)-functionalized reduced graphene oxide (PPD-rGO) as the counter electrode divulged a specific capacitance of 72.5 F g-1 at 2 A g-1 current density with ∼70% capacitive retention after 2200 successive charge-discharge cycles over a broad potential window of 0-1.6 V. Moreover, the ASC demonstrated a maximum power density of 11.9 kW kg-1 at 10 A g-1 and a maximum energy density of 25.8 W h kg-1 at 2 A g-1 current density. Owing to the stable electrochemical redox (Co2+/Co3+)-mediated pseudocapacitive behavior of the Co-MOF and the high surface area and electrical conductivity of in situ generated PPD-intercalated rGO, the fabricated ASC unveiled high-performance supercapacitive behaviors. To investigate the practical applicability of this material, solid-state (ASC) devices were fabricated by employing the Co-MOF as the positive electrode and PPD-rGO as the negative electrode in a KOH-based gel electrolyte, which could power a commercially available light-emitting diode bulb (∼1.8 V) for several seconds. Therefore, the elucidated high electrochemical energy storage performance of the prepared Co-MOF makes it a very promising electrode material for supercapacitors.

Uncovering the centrality of mono-dentate SO32-/SO42- modifiers grafted on a metal vanadate in accelerating wet NOX reduction and poison pyrolysis

NOX rarely binds with labile oxygens of catalytic solids, whose Lewis acidic (LA) species possess higher binding strengths with NH3 (ENH3) and H2O than Brönsted acidic counterparts (BA--H+; -OH), oftentimes leading to elevate energy barrier (EBARRIER) and weaken H2O tolerance, respectively. These limit NH3-assisted wet NOX reduction via Langmuir-Hinshelwood-type or Eley-Rideal (ER)-type model on LA species, while leaving ER-type analogue on BA--H+ species proper to reduce wet NOX. Given hard-to-regulate strength/amount of -OH species and occasional association between ENH3 and EBARRIER, Ni1V2O6 (Ni1) was rationally chosen as a platform to isolate mono-dentate SO32-/SO42- species for use as BA--H+ bonds via protonation to increase collision frequency (k'APP,0) alongside with disclosure of advantages of SO32-/SO42--functionalized Ni1V2O6 (Ni1-S) over Ni1 in reducing wet NOX. Ni1-S outperformed Ni1 in achieving a larger BA--H+ quantity (k'APP,0↑), increasing H2O tolerance, and elevating oxygen mobility, thus promoting NOX reduction activity/consequences under SO2-excluding gases. V2O5-WO3 composite simulating a commercial catalyst could isolate mono-dentate SO32-/SO42- species and served as a control (V2O5-WO3-S) for comparison. Ni1-S was superior to V2O5-WO3-S in evading ammonium (bi-)sulfate (AS/ABS) poison accumulation and expediting AS/ABS pyrolysis efficiency, thereby improving AS/ABS resistance under SO2-including gases, while enhancing resistance against hydro-thermal aging.

Nickel vanadate nitrogen-doped carbon nanocomposites for high-performance supercapacitor electrode

A nickel-vanadium-based bimetallic precursor was produced using the polymerization process by urea-formaldehyde copolymers. The precursor was then calcined at 800 °C in an argon ambiance to form a Ni3V2O8-NC magnetic nanocomposite. Powerful techniques were used to study the physical characteristics and chemical composition of the fabricated Ni3V2O8-NC electrode. PXRD, Raman, and FTIR analyses proved that the crystal structure of Ni3V2O8-NC included N-doped graphitic carbon. FESEM and TEM analyses imaging showed the distribution of the Ni3V2O8 nanoparticles on the layered graphitic carbon structure. TEM images showed the prepared sample has a particle size of around 10-15 nm with an enhanced active site area of 146 m2/g, as demonstrated by BET analysis. Ni3V2O8-NC nanocomposite exhibits magnetic behaviors and a magnetization saturation value of 35.99 emu/g. The electrochemical (EC) studies of the synthesized Ni3V2O8-NC electrode proceeded in an EC workstation of three-electrode. In a 5 M potassium hydroxide as an electrolyte, the cyclic voltmeter exhibited an enhanced capacitance (CS) of 915 F/g at 50 mV/s. Galvanic charge-discharge (GCD) study also exhibited a superior capacitive improvement of 1045 F/g at a current density (It) of 10 A/g. Moreover, the fabricated Ni3V2O8-NC nanocomposite displays a good power density (Pt) of 356.67 W/kg, improved ion accessibility, and substantial charge storage. At the high energy density (Et) of 67.34 W h/kg, the obtained Pt was 285.17 W/kg. The enhanced GCD rate, cycle stability, and Et of the Ni3V2O8-NC magnetic nanocomposite nominate the sample as an excellent supercapacitor electrode. This study paves the way for developing effective, efficient, affordable, and ecologically friendly electrode materials.

Banana Peel and Conductive Polymers-Based Flexible Supercapacitors for Energy Harvesting and Storage

Flexible supercapacitors are highly demanding due to their wearability, washability, lightweight property and rollability. In this paper, a comprehensive review on flexible supercapacitors based on conductive polymers such as polypyrrole (PPy), polyaniline (PANI) and poly(3,4-ethylenedioxtthiophne)-polystyrene sulfonate (PEDOT:PSS). Methods of enhancing the conductivity of PEDOT:PSS polymer using various composites and chemical solutions have been reviewed in detail. Furthermore, supercapacitors based on carbonized banana peels and methods of activation have been discussed in point. This review covers the up-to-date progress achieved in conductive polymer-based materials for supercapacitor electrodes. The effect of various composites with PEDOT:PSS have been discussed. The review result indicated that flexible, stretchable, lightweight, washable, and disposable wearable electronics based on banana peel and conductive polymers are highly demanding.

Toward Enhanced Electrochemical Performance by Investigation of the Electrochemical Reconstruction Mechanism in Co2V2O7 Hexagonal Nanosheets for Hybrid Supercapacitors

As for hybrid supercapacitors, it is important to enhance the long cycling performance and high specific capacitance. In this paper, cobalt vanadate (Co₂V₂O₇) hexagonal nanosheets on nickel foam are manufactured by a facile hydrothermal method and then transformed into numerous smaller size interconnected hierarchical nanosheets without any shape change via electrochemical reconstruction. Benefiting from the favorable architecture of hierarchical nanosheets via electrochemical reconstruction, the Co₂V₂O₇ hexagonal nanosheet electrode exhibits a remarkable long cycling performance with 272% specific capacitance retention after 100,000 cycles at a current density of 5 A g^-1 and then displays an increasing specific capacitance of 1834 F g^-1 (tested at 1 A g^-1). Furthermore, an aqueous hybrid supercapacitor device based on the Co₂V₂O₇ hexagonal nanosheet electrode exhibits a high energy density of 35.2 Wh kg^-1 at a power density of 1.01 kW kg^-1 and an excellent cyclic stability with 71.4% capacitance retention after 10,000 cycles at 5 A g^-1. These results offer a practicable pathway for enhancing the electrochemical properties of other metal oxides through electrochemical reconstruction.

Flexible, Transparent and Highly Conductive Polymer Film Electrodes for All-Solid-State Transparent Supercapacitor Applications

Lightweight energy storage devices with high mechanical flexibility, superior electrochemical properties and good optical transparency are highly desired for next-generation smart wearable electronics. The development of high-performance flexible and transparent electrodes for supercapacitor applications is thus attracting great attention. In this work, we successfully developed flexible, transparent and highly conductive film electrodes based on a conducting polymer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The PEDOT:PSS film electrodes were prepared via a simple spin-coating approach followed by a post-treatment with a salt solution. After treatment, the film electrodes achieved a high areal specific capacitance (3.92 mF/cm² at 1 mA/cm²) and long cycling lifetime (capacitance retention >90% after 3000 cycles) with high transmittance (>60% at 550 nm). Owing to their good optoelectronic and electrochemical properties, the as-assembled all-solid-state device for which the PEDOT:PSS film electrodes were utilized as both the active electrode materials and current collectors also exhibited superior energy storage performance over other PEDOT-based flexible and transparent symmetric supercapacitors in the literature. This work provides an effective approach for producing high-performance, flexible and transparent polymer electrodes for supercapacitor applications. The as-obtained polymer film electrodes can also be highly promising for future flexible transparent portable electronics.

Rational Synthesis of "Grape-like" Ni2 V2 O7 Microspheres as High-capacity Anodes for Rechargeable Lithium Batteries

Vanadates have received booming attention recently as promising materials for extensive electrochemical devices such as batteries and electrocatalysis. However, the enormous difficulties of achieving pure-phase transition metal vanadates, especially for nickel-based, hinder their exploitations. Herein, for the first time, by controlling the amount of ethylene glycol (EG) and reaction time, grape-like Ni₂ V₂ O₇ (or V₂ O₅ /Ni₂ V₂ O₇ ) microspheres were rationally fabricated. It is demonstrated that the EG can chelate both Ni²⁺ and VO₃ ^- to form organometallic precursors. As anode in lithium-ion batteries (LIBs), it could deliver superior reversible capacity of 1050 mAh/g at 0.1 A/g and excellent rate capability of 600 mAh/g at 4 A/g. The facile hydrothermal synthesis broadens the material variety of nickel vanadates and offers new opportunities for their wider applications in electrochemistry.

Smart-Fabric-Based Supercapacitor with Long-Term Durability and Waterproof Properties toward Wearable Applications

The rapid development of wearable electronics and smart textiles has dramatically motivated the generation of flexible textile-based supercapacitors (SCs). However, the rapid evaporation of water moisture in gel electrolyte substantially limits the working durability and performance enhancements of the flexible devices. Therefore, a high-performance multifunctional textile-based SC with long-term durability is highly desired. Herein, a poly(vinyl alcohol) (PVA)/polyacrylamide (PAM) composite gel electrolyte was developed to fabricate multifunctional device with water-retaining and water-proofing properties based on multidimensional hierarchical fabric. And the assembled SC based on composite gel exhibited a superior water-retaining property and long-term working durability (93.29% retention rate after operation for 15 days), whereas the performance of SC based on pure PVA gel declined sharply and only 43.2% capacitance remained. In addition, the assembled SC exhibited enhanced specific capacitance of 707.9 mF/cm² and high energy density of 62.92 μWh/cm² and maintained a good stability of 80.8% even after 10 000 cyclic tests. After water repellency treatment, the integrated device immersed in water could still work normally. What's more, the assembled devices could be charged by a portable hand generator, which could be potentially applied for field rescue and military applications. We foresee that this strategy would be a potential route to prepare high-performance multifunctional textile-based SCs for wearable electronic systems and smart textile applications.

Sulfur and nitrogen-doped graphene quantum dots/PANI nanocomposites for supercapacitors

Sulfur and nitrogen-doped graphene quantum dots/polyaniline nanocomposites were synthesized and their electrochemical charge storage properties were tested for supercapacitor applications.

Multifunctional coatings of exfoliated and reassembled graphite on cellulosic substrates

Exfoliated and reassembled graphite (ERG) forms macroscopic, high aspect ratio (1 : >10⁶) and highly conductive coating layers that are strongly adherent to paper, wood, cloth, ceramic and other substrates. The coating precursor is an aqueous dispersion of graphite that exfoliates spontaneously in alkaline cellulose solutions, forming stable dispersions. These can be applied to the substrates by using different painting, coating and lithography techniques. The coating morphology changes from highly smooth to porous and rough, depending on the finishing procedure used. Coated paper sheets are flexible and they perform as leads in electrical circuitry and as electrodes in electrodeposition, supercapacitors, hygroelectricity cells and other electrochemical devices suitable for flexible and wearable electronics. These unique properties of ERG are explained as a consequence of the amphiphilic character of cellulose, which allows it to play the roles of exfoliant, dispersant, stabilizer, adhesive and plasticizer, while graphite powder is transformed into a cohesive laminated nanocomposite.

Fabrication and Electrochemical Performance of PVA/CNT/PANI Flexible Films as Electrodes for Supercapacitors

The flexible and rechargeable energy storage device with excellent performance is highly desired due to the demands of portable and wearable devices. Herein, by integrating the bendability and stretchability of Polyvinyl alcohol (PVA), pseudocapacitance of Polyaniline (PANI), and the charge transport ability of carbon nanotubes (CNTs), PVA/CNT/PANI flexible film was fabricated as supercapacitor electrodes with excellent electrochemical performance and flexibility. Full-solid supercapacitor is prepared based on PVA/H₂SO₄ gel electrolyte and as-prepared film electrodes. The device achieves an areal capacitance of 196.5 mF cm^-2 with high cycling stability. The flexible properties of PVA, the conductivity of CNT, and the pseudo-capacitance of PANI contribute to the superior performance. Present work develops a facile and effective way for preparing flexible electrode materials. In present work, we fabricated PVA/CNT/PANI flexible film as supercapacitor electrodes with excellent electrochemical performance and flexibility.

Controlling Electrode Spacing by Polystyrene Microsphere Spacers for Highly Stable and Flexible Transparent Supercapacitors

Transparent polymer electrolytes such as poly(vinyl alcohol)-based H⁺, Li⁺, K⁺, and Na⁺ gels have been widely used as both an electrolyte and a separator for flexible transparent supercapacitors (FTSCs). However, these gels sandwiched between the electrodes in FTSCs are easily compressed under bending and compression due to their viscous flow behavior, resulting in the deformation of electrode spacing and the unstable capacitance performance. To resolve this issue, herein, we introduce monodispersed polystyrene (PS) microspheres into PVA-LiCl polymer gel electrolytes as spacers to precisely control the electrode spacing during the assembly of FTSCs using single-walled carbon nanotubes/indium tin oxide-polyethylene terephthalate (ITO-PET) or MnO₂/multiwalled carbon nanotubes/ITO-PET as transparent electrodes. The electrode spacing could be tuned by varying the diameter of PS microspheres, for example, 20, 40, and 80 μm. More importantly, the PS microsphere spacers protect the gel electrolyte from the squeeze when bending takes place, allowing the stable performance output by FTSCs under a bending state. After repeating bending tests, the capacitance remains 95.6%, indicating the high stability and flexibility of the devices with the assistance of PS microsphere spacers.

Design and synthesis of hierarchical NiO/Ni3V2O8 nanoplatelet arrays with enhanced lithium storage properties

Hierarchical NiO/Ni₃V₂O₈ nanoplatelet arrays (NPAs) grown on Ti foil were prepared as free-standing anodes for Li-ion batteries (LIBs) via a simple one-step hydrothermal approach followed by thermal treatment to enhance Li storage performance. Compared to the bare NiO, the fabricated NiO/Ni₃V₂O₈ NPAs exhibited significantly enhanced electrochemical performances with superior discharge capacity (1169.3 mA h g⁻¹ at 200 mA g⁻¹), excellent cycling stability (570.1 mA h g⁻¹ after 600 cycles at current density of 1000 mA g⁻¹) and remarkable rate capability (427.5 mA h g⁻¹ even at rate of 8000 mA g⁻¹). The excellent electrochemical performances of the NiO/Ni₃V₂O₈ NPAs were mainly attributed to their unique composition and hierarchical structural features, which not only could offer fast Li⁺ diffusion, high surface area and good electrolyte penetration, but also could withstand the volume change. The ex situ XRD analysis revealed that the charge/discharge mechanism of the NiO/Ni₃V₂O₈ NPAs included conversion and intercalation reaction. Such NiO/Ni₃V₂O₈ NPAs manifest great potential as anode materials for LIBs with the advantages of a facile, low-cost approach and outstanding electrochemical performances.

Hierarchical NiO/Ni₃V₂O₈ nanoplatelet arrays (NPAs) grown on Ti foil were prepared as free-standing anodes for Li-ion batteries (LIBs) via a simple one-step hydrothermal approach followed by thermal treatment to enhance Li storage performance.

Recyclable and tear-resistant all-in-one supercapacitor with dynamic electrode/electrolyte interface

All-in-one supercapacitors constitute an indispensable part in adapting to the rapid development of flexible energy storage equipment. Herein, an all-in-one configured PANI supercapacitor with a dynamic electrode/electrolyte interface was designed through hydrogen bonds and metal coordination bonds. The supercapacitor exhibits remarkable electrochemical capacitance (162 F g^-1 at 0.5 A g^-1, 137.4 mF cm^-2 at 0.5 A cm^-2) and excellent structural stabilities (almost no degradation in performance and structural damage in the cases of bending, folding, stretching and self-healing process). Besides, the hydrogel electrode can be efficiently recycled through a convenient method without virtual loss of electrochemical performance. Construction of the dynamic interface inside the supercapacitor provides a practical guidance for large-scale preparation of flexible energy storage devices, electronic skin and stretchable sensors.

Facile Synthesis of Novel V0.13Mo0.87O2.935 Nanowires With High-Rate Supercapacitive Performance

Binary metal oxides composed of molybdenum–vanadium oxides are promising candidates for supercapacitors. Here, we report the synthesis of one-dimensional V_0.13Mo_0.87O_2.935 nanowires through a facile one-step hydrothermal method. This nanowire presented a high specific capacitance of 394.6 F g⁻¹ (1 mV s⁻¹) as an electrode applied to the supercapacitor. Importantly, this electrode showed a perfect rate capability of 91.5% (2 to 10 A g⁻¹) and a continuous verified outstanding cyclic voltammetry of 97.6% after 10,000 cycles. These superior electrochemical properties make the synthesized V_0.13Mo_0.87O_2.935 nanowires a prospective candidate for high-performance supercapacitors.

A facile method to synthesize CoV2O6 as a high-performance supercapacitor cathode

Transition metal oxides can easily lose electrons and thus possess multiple accessible valences. Especially, if two different transition metals are combined, better capacity and cycling stability are achieved. In this study, a binary transition metal oxide, CoV₂O₆, was synthesized via a facile co-precipitation process for use as a supercapacitor cathode; the as-synthesized CoV₂O₆ exhibited high-capacity (306.6 F g⁻¹, 1 A g⁻¹ and 219.2 F g⁻¹, 20 A g⁻¹) and stable cycling stability, retaining 83.3% of its initial specific capacitance after 20 000 cycles. We believe that this facile synthesis process presents an effective method and a new opportunity for promoting the application of electrode materials based on binary transition metal oxides in supercapacitors.

A facile chemical co-precipitation process to synthesize CoV₂O₆, which exhibits high capacity and cycling stability (83.3% after 20 000 cycles).

The NiGa-LDH@NiWO4 nanocomposite as an electrode material for pseudocapacitors

NiGa-LDH@X-NiWO₄ (X: 3, 5 or 10 wt% NiWO₄) nanocomposites were prepared at room temperature under mild conditions.