Advanced Supercapacitors Research Articles

Asymmetric supercapacitor properties of fern-like nanostructured NiCo2S4 synthesized through a one-pot simple solvothermal method

Nanoarchitectures of ternary NiCo2S4 are desirable for the development of advanced high-performance supercapacitors. Herein, we demonstrate a simple solvothermal synthesis procedure for a fern-like nanoarchitecture of NiCo2S4 on Ni foam. The electrode exhibits a good areal capacity of approximately 1.55F cm−2 at a current density of 10 mA cm−2, while the ASC device exhibits an areal capacity of approximately 1.02 F cm−2 at 12 mA cm−2 and retention of 75.3% over 8000 charge–discharge cycles.

Rational design of 2D/1D ZnCo-LDH hierarchical structure with high rate performance as advanced symmetric supercapacitors

Hierarchical microstructures of electrode materials for supercapacitors have attracted strong attention owing to the enlarged surface area, fast charge transportation and enhanced volume expansion. All these advantages of hierarchical structures are available for facilitating the electrochemical performances and stability of electrode materials for advanced supercapacitors. However, few reports focused on the development of transition metal-based homogeneous 2D/1D hierarchical structures use the same material. Herein, the ZnCo-LDH with 3D hierarchical microstructure was self-assembled with 1D nanoneedles and 2D nanosheets that in situ synthesized on Ni foam through a simple and effective strategy. The optimal sample (ZnCo-LDH-2) exhibited the ultra-high specific capacitance of 3871.2 F g −1 at 1 A g −1 and excellent cycle life span (capacitance retention of 87.5% after 6000 cycles at 5 A g−1). Particularly, the current density was as high as 100 A g−1, the specific capacitance of ZnCo-LDH-2 still remained 1526 F g−1. Moreover, the symmetric supercapacitor (SSC) fabricated with ZnCo-LDH-2 showed the maximum energy density of 40.3 Wh kg−1 and power density of 15.08 kW kg−1.

Rational construction of ternary ZnNiP arrayed structures derived from 2D MOFs for advanced hybrid supercapacitors and Zn batteries

Exploiting nickel-based phosphide electrodes for next-generation high-performance supercapacitors and secondary batteries with high security has attracted great attentions. Herein, we fabricated binderless ZnNiP electrode based on Ni metal-organic framework and the optimized Zn-doping process, which achieved high electrochemical performance both in hybrid supercapacitor and Zn battery. Encouragingly, the addition of Zn source and the phosphating process make a component synergy with enhanced electronic conductivity, enriched electrochemical active centers and redox reactions. The ZnNiP-0.5 with sturdy construction exhibits a remarkable specific capacity and a good cycling stability in alkaline electrolyte. When assembled to hybrid supercapacitor, the installation delivers a maximum energy density of 67.4 Wh kg−1, a maximum power density of 15.9 kW kg−1, and outstanding cycling performance (88% retention after 10 000 cycles). Additionally, the fabricated Zn battery could achieve discharge voltage of~ 1.9 V, with an admirable energy density of 529.58 Wh kg−1 and also shows the excellent durability (capacity retention of 91.6% after 3000 cycles). This work offers a feasible route and provides a certain guiding significance for the reasonable design of binder-free electrodes with delicate structures and compositions, which may inspire new significative findings of building electrodes for high-security hybrid supercapacitors and alkaline batteries.

Nickel bismuth oxide as negative electrode for battery-type asymmetric supercapacitor

• Nanostructured materials were prepared using facile wet chemical route. • Nickel bismuth oxide displayed quasi-conversion reaction. • 12 mol% CeO 2 added NiO has yielded capacity of 543 C g −1 with 102.9% retention. • The fabricated BASCs could deliver energy of 78 W h kg −1 at power of 201 W kg −1 . • The charged cell could energize the 30 Red LEDs. One of the main variables for achieving superior electrochemical efficiency is the development of an innovative and advanced supercapacitor negative electrode. This paper presents and explores the development of novel and advanced nanostructures of nickel bismuth oxide and their electrochemical activity as negative electrodes in the construction of a battery-type asymmetric supercapacitor. It could yield a specific capacity of 443 C g −1 (at 2 mA cm −2 ) within the potential window of – 1.1 to 0 V. In addition, NiO/CeO 2 nanocomposites have been prepared to improve long term cyclic stability of NiO electrode materials and used as the counter electrode to nickel bismuth oxide in the assembly of supercapacitor cells. A maximum capacity of 543 C g −1 (at 2 mA cm −2 ) is estimated for the NiO nanocomposites containing 12 mol% ceria in the potential window of – 0.05 to 0.4 V. The fabricated NC12//NBO battery-type asymmetric supercapacitor cell reveals Faradic characteristics and they provide the specific capacity of 374 C g −1 (2 mA cm −2 ) along with 95.6% capacity retention after 5000 GCD cycles. Moreover, the fabricated cell delivers a specific energy of 78 W h kg −1 (at 201 W kg −1 ) and retains 41.1% energy even at a high specific power of 3.2 kW kg −1 . The NC12//NBO asymmetric cell was used to power 30 Red LEDs. The outstanding electrochemical behaviour of nickel bismuth oxide electrode suggests it to be a promising negative electrode material in the fabrication of asymmetric supercapacitor.

Fabrication of Rambutan-like Activated Carbon Sphere/Carbon Nanotubes and Their Application as Supercapacitors

Developing advanced electrochemical double-layer supercapacitors (EDLCs) with high energy density and capacitance can be realized by exploring the electrodes possessing large specific surface area ...

Structure-designed synthesis of hollow/porous cobalt sulfide/phosphide based materials for optimizing supercapacitor storage properties and hydrogen evolution reaction

Cobalt-based transition metal phosphides/sulfides have been viewed as promising candidates for supercapacitor (SCs) and hydrogen evolution reaction (HER) featured with their intrinsic merits. Nevertheless, the sluggish reaction kinetics and drastic volume expansion upon electrochemical process hinder their commercial application. In this work, the hollow/porous cobalt sulfide/phosphide based nanocuboids (C-CoP4 and CoS2 HNs) with superior specific surface area are achieved by employing a novel chemical etching-phosphatization/sulfuration strategy. The hollow/porous structure could offer rich active sites and shorten electrons/ions diffusion length. In virtue of their structural advantage, the obtained C-CoP4 and CoS2 HNs perform superior specific capacitance, fast charge/discharge rate and beneficial cycling stability. The advanced asymmetrical supercapacitors assembled by C-CoP4 and CoS2 HNs deliver exceptional energy density, respectively. Furthermore, when employed as hydrogen evolution reaction electrocatalysts, C-CoP4 and CoS2 HNs yield favorable electrocatalytic activity. These findings shed fundamental insight on the design of dual-functional transition metal phosphide/sulfide based materials for optimizing hydrogen evolution reaction and supercapacitor storage properties.

3D flower-like nickel cobalt sulfide directly decorated grassy nickel sulfide and encapsulated iron in carbon sphere hosts as hybrid energy storage device

Developing high-performance supercapacitors is of great significance in the area of renewable energies by virtue of having both high energy and power densities. In this work, an innovative strategy is employed for the fabrication of binder-free binary nickel–cobalt-sulfide (NCS) nanosheets (NSs) directly decorated onto the hydrothermal nickel-sulfide (Ni3S2) nanowires (NWs) as the positive electrodes. The NCS/Ni3S2-nickel foam (NF) positive electrodes rendered superior specific capacity of 499.1 mAh.g−1 at 6 A.g−1. Encapsulated iron into the carbon sphere hosts (Fe-HTCSs) are used as the negative counterparts, exhibiting remarkable specific capacitance of 336.6 F.g−1 (at 0.1 A.g−1). The prepared positive and negative electrodes are on the merit of developing advanced asymmetric supercapacitors (ASCs) by virtue of encouraging electrochemical results. The fabricated NCS/Ni3S2-NF//Fe-HTCS ASCs not only possess a wide operating potential window (1.7 V), but also receive benefits from high energy (46.2 Wh.kg−1) and power densities (2.0 kW.kg−1), which secure the applicability of the assembled ASC devices in high-performance electronics and renewable energy systems.

Assembling Co3O4 Nanoparticles into MXene with Enhanced electrochemical performance for advanced asymmetric supercapacitors

MXenes with unique 2D open structure, large surface-area-to-volume ratios, high pseudo-capacitance, and conductivity are attractive for advanced supercapacitor electrodes. However, the restacking issue of MXenes hinders ion accessibility, resulting in the reduction of volume performance, mass load, and speed capability. To address these issues, a facile hydrothermal synthesis strategy is proposed to fabricate Co3O4 nanoparticles-MXene (Co-MXene) composite by the self-assembly process. Co3O4 nanoparticles, introduced in the MXene matrix, effectively prevent self-restacking and shorten ion/electron transport paths. Consequently, the obtained Co-MXene electrode delivers the high-performance of 1081F g−1 at a current density of 0.5 A g−1, surpassing the pristine MXene electrode (89F g−1 at 0.5 A g−1). Being assembled into asymmetric supercapacitors (ASC), a high energy density of 26.06 Wh kg−1 at 700 W kg−1 was realized. After 8000 cycles, the ASC device maintains 83% of initial specific capacitance at 2 A g−1. This work highlights a simple and efficient method for developing high-performance MXene-based electrodes for supercapacitors.

Synthesis of Co3O4/CoVxOy core-shell nanosheets arrays with interweaved nanowires as cathode materials for asymmetric supercapacitors

Rational optimization design for the structure of materials on the self-supported electrode usually be an effective strategy for the development of advanced supercapacitors. Herein, the Co3O4/CoVxOy nanosheets composed of interweaved nanowires with core-shell structure were prepared through the two-step hydrothermal process combined with annealing treatment. These electrode materials exhibited a high specific capacitance of 1162.2 F g−1 at 1 A g−1, a good rate capability and a satisfactory cycling life. Asymmetric devices were fabricated using an as-prepared electrode as a positive electrode and activated carbon as a negative electrode, which delivered the highest energy density of 26.1 Wh kg−1 with a power density of 400 W kg−1 in the voltage range of 0–1.6 V. This work with the encouraging results point out the as-obtained Co3O4/CoVxOy composites not only can be a promising candidate for the energy storage system but also present a practicable route to design nanosheets core-shell structures for other transition metal oxides.

High-Mass-Loading Electrodes for Advanced Secondary Batteries and Supercapacitors

The growing demand for advanced electrochemical energy storage systems (EESSs) with high energy densities for electric vehicles and portable electronics is driving the electrode revolution, in which the development of high-mass-loading electrodes (HMLEs) is a promising route to improve the energy density of batteries packed in limited spaces through the optimal enlargement of active material loading ratios and reduction of inactive component ratios in overall cell devices. However, HMLEs face significant challenges including inferior charge kinetics, poor electrode structural stability, and complex and expensive production processes. Based on this, this review will provide a comprehensive summary of HMLEs, beginning with a basic presentation of factors influencing HMLE electrochemical properties, the understanding of which can guide optimal HMLE designs. Rational strategies to improve the electrochemical performance of HMLEs accompanied by corresponding advantages and bottlenecks are subsequently discussed in terms of various factors ranging from inactive component modification to active material design to structural engineering at the electrode scale. This review will also present the recent progress and approaches of HMLEs applied in various EESSs, including advanced secondary batteries (lithium-/sodium-/potassium-/aluminum-/calcium-ion batteries, lithium metal anodes, lithium-sulfur batteries, lithium-air batteries, zinc batteries, magnesium batteries) and supercapacitors. Finally, this review will examine the challenges and prospects of HMLE commercialization with a focus on thermal safety, performance evaluation, advanced characterization, and production cost assessment to guide future development.

Interface Engineering Based on Multinanoscale Heterojunctions between NiO Quantum Dots, N-Doped Amorphous Carbon and Ni for Advanced Supercapacitor

Energy storage ability is determined by the ion arrangement and electron transfer at the electrode–electrolyte interface, which depends on combining materials that form complex heterogeneous interf...

Macaroni Fullerene Crystals-Derived Mesoporous Carbon Tubes as a High Rate Performance Supercapacitor Electrode Material

Abstract Self-assembled macaroni fullerene C60 crystals (MFCs) of uniform shape and narrow size distribution are produced using the dynamic liquid-liquid interfacial precipitation method under ambient conditions. High temperature heat treatment (900 °C) of MFCs yields mesoporous carbons tubes (MCTs) retaining the initial morphology. This novel mesoporous carbon material exhibits excellent electrochemical supercapacitive performance due to high surface areas (1544 m2 g−1), large pore volume (2.936 cm3 g−1) and interconnected porous structures. In a three-electrode aqueous electrolyte system, the electrode achieved high specific capacitance ca. 422 F g−1 at a current density of 1 A g−1 followed by excellent cycling stability (>95%) after 10,000 charging-discharging cycles at 20 A g−1. We believe that the novel mesoporous carbon material derived from a π-electron carbon source can be used as an alternative electrode material in advanced supercapacitor devices.

Synthesis of nitrogen-doped porous carbon and partial poly (2, 2′-dithiodianiline) composite as advanced supercapacitor electrode materials

Composited materials (NC/PDTDA) of nitrogen-doped porous carbon (NC) and partial poly (2, 2′-dithiodianiline) (PDTDA) have been successfully synthesized by in-situ polymerization and can be utilized in alkaline electrolytes as electrodes for supercapacitors. The physiochemical properties of NC/PDTDA composites materials are characterized by field emission scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscopy, Raman spectrum, X-ray electron spectrum, and X-ray diffraction. In addition, the electrochemical properties of NC/PDTDA composites materials are tested in 3 M KOH aqueous solution with a representative three-electrode system. It shows the highest specific capacitance when the mass ratio of NC to PDTDA is 1:2 (NC/PDTDA-2), and the specific capacitance is 490.5 F/g at a current density of 1 A/g. More significantly, the asymmetric supercapacitor is also assembled with an extended operating voltage window of 1.4 V in PAM-PVA- KOH electrolyte. It exhibits an energy density of 13.49 Wh/Kg at a power density of 699.8 W/Kg.

Induced conducting energy-levels in a boron nitride nano-framework for asymmetric supercapacitors in high charge-mobility ionic electrolytes

Boron nitride's (BN) large band gap does not permit carrier transport at ambient conditions. We show that BN sheets can be exfoliated by functionalization with oxy-groups to introduce additional acceptor and donor energy levels appropriate for energy storage devices. Further, the incorporation of heteroatoms into transition metal sulfides enhances capacitance via Faradic redox reactions and their cyclic stability. The functionalized boron nitride (mK-BN) and Carbon Nanotubes (CNTs) are intertwined with a Zn-doped Cadmium-Sulfide (Zn–CdS) nanostructure to increase the surface area-charge storage. In a supercapacitor application, Zn–CdS/mK-BN/CNT exhibits a 787 F/g specific capacitance (SC) in an aqueous (aq.) electrolyte. Further, the Zn–CdS/mK-BN/CNT was deployed as a cathode material in an asymmetric supercapacitor device (ASC) coupled with an ionic electrolyte (IE), (NHEt3)+(NO3)−, offered a SC of 173 F/g with an approximate 99% stability due to the enhanced charge mobility. The reported functionalization of BN induces additional energy levels making the material ideal for energy storage devices and will directly impact the next-generation of advanced supercapacitor electrode materials.

Implantable and Biodegradable Micro-Supercapacitor Based on a Superassembled Three-Dimensional Network Zn@PPy Hybrid Electrode.

Transient supercapacitors (TSCs), a new type of advanced supercapacitor (SC) that can completely dissolve with environmentally and biologically benign byproducts in vivo after performing their specified function, have broad application prospects in the fields of green electronics, implantable devices, personalized medicine, military security, and other fields. However, research on TSCs is still in its infancy, and there are still many challenges to be solved, such as the complex preparation process and low energy density. Herein, we report a facile superassembly manufacturing method for an implantable and fully biodegradable three-dimensional network Zn@PPy hybrid electrode by screen printing and electrochemical deposition. The produced superassembled interdigital pseudocapacitor exhibits superior electrochemical performances due to the high capacitances and excellent rate performances of the pattern Zn@PPy electrode and NaCl/agarose electrolyte. An optimized biodegradable SC exhibits a maximum energy density of 0.394 mW h cm-2 and can be fully degraded in vivo in 30 days without any adverse effects in the host organism. This work provides a new platform for transient electronic technology for diverse implantable electronic applications.

A robust magnesiothermic reduction combined self-activation strategy towards highly-curved carbon nanosheets for advanced zinc-ion hybrid supercapacitors applications

Aqueous zinc-ion hybrid supercapacitors are considered to be a newly emerging electrochemical energy storage devices. However, the exploration and design of advanced cathode materials remain a huge challenge. Herein, we developed a versatile one-step magnesiothermic reduction and self-activation process for the synthesis of highly-curved carbon nanosheets (HCCNs) with hierarchical pore structures. In this process, low-molecular weight organic potassium salts (e.g. potassium bitartrate, potassium acetate, potassium oxalate, potassium formate, potassium oleate, potassium sorbate), which usually used as the chemical activating reagents, serve as the carbon source whereas the Mg power acts as the reducing agent. The resulting HCCNs possess hierarchical porosity and unique HCCN geometry which can afford abundant active sites for charge accumulation as well as the highly efficient ions diffusion kinetics. Because of the high ratio of surface-controlled capacitive contribution and high ions diffusion coefficient, the optimized sample can exhibit excellent charge storage performance with an impressive reversible capacity (200.2 mAh g–1), excellent rate capability, and good cyclic stability. The excellent capacitive behaviors combined with the feasible synthetic procedure make the present synthetic protocol a promising choice towards well-designed nanocarbons for electrochemical energy storage applications.

Hierarchically activated porous carbon derived from zinc-based fluorine containing metal-organic framework as extremely high specific capacitance and rate performance electrode material for advanced supercapacitors

In this work, a hierarchically activated porous carbon (APC) was synthesized using fluorine-containing metal-organic framework via facile combined carbonization and KOH activation treatments. The influences of activation conditions on the surface structures and electrochemical performance of APC were systematically studied. Afterwards, the electrochemical responses of APC electrode were further assessed from the cyclic voltammetry and galvanostatic charge-discharge examinations by 6 M KOH electrolyte. The as-obtained APC electrode delivered the high specific capacitances of 540.8 and 280 F g−1 at 1 and 500 A g−1, correspondingly with superior capacitance retention of 94% after 250,000 cycles even at 100 A g−1, which is showing that its outstanding capacitance, remarkable rate capacity, and very-long cyclic life. Furthermore, the as-assembled APC-based symmetrical supercapacitor offers a superb energy density of 19 Wh kg−1 at 182 W kg−1, indicating its large-scale application. Thus, this work proposes a potential route to synthesize highly efficient porous carbon material for the future development of energy storage systems.

Anchoring Ni-MOF nanosheet on carbon cloth by zeolite imidazole framework derived ribbonlike Co3O4 as integrated composite cathodes for advanced hybrid supercapacitors

Metal-organic frameworks (MOFs) and their derivatives as electrode materials for energy storage and conversion are intriguing. However, the in-situ uniformly and firmly growing metal-organic framework materials directly on conductive substrates is limited and still challenging. Herein, an effective strategy is presented by constructing a ribbonlike Co3O4 nanoarrays that derived from zeolite imidazole framework (ZIF) on carbon cloth as “fixed piles” for the in-situ solvothermal synthesis of Ni-MOF nanosheets. As a result, the Ni-MOF nanosheets closely distribute on the surface of the carbon cloth with fluffy structure, which favors exposure of more active sites and rapid diffusion of electrolyte ions. The as-fabricated integrated composite electrode (Co3O4@Ni-MOF) delivers a good specific capacitance of 1416 F/g at the current density of 1 A/g, superior to the individual Co3O4 (410 F/g) and Ni-MOF electrode (690 F/g). Moreover, the specific capacitance can be kept at 90% of its original value after 3000 cycles. Based on these advantages, a hybrid supercapacitor fabricated by the Co3O4@Ni-MOF electrode and activated carbon (AC) shows prominent energy density of 68.6 Wh kg−1 at the power density of 510 W kg−1, and excellent cycling stability (about 12% capacitance loss after 5000 charge-discharge cycles).

A green and economical approach to derive biomass porous carbon from freely available feather finger grass flower for advanced symmetric supercapacitors

Presently, the porous carbon derived from natural biomass wastes hold a prominent position as electrode material in supercapacitors from its wonderful features of huge surface area, cost-effectiveness, freely available precursor, easy to preparation and eco-friendly nature. Thus, in the present study, we propose a new hollow tubular-like porous carbon (HT-PC) from the more sustainable and freely available feather finger grass flower (FFGF) with high electrochemical behavior as an active electrode for supercapacitors. The combination of carbonization and KOH activation treatments were carried out to prepare HT-PC from natural FFGF. The as-prepared biomass HT-PC containing the different sized micro-pore arrangement with a huge surface area (637.1 m2 g−1) after performed KOH activation treatment at the optimized condition. The three-electrode system measurements reveal that as-prepared HT-PC provides a remarkable specific capacitance of 315 F g−1 at 1 A g−1 and 262 F g−1 at 100 A g−1 with keeping 96% of capacitance over 50,000 cycles at 50 A g−1 using 6 M KOH aqueous electrolyte. In addition to that, the HT-PC electrode-based symmetrical supercapacitor releases high specific energy of 18.75 Wh kg−1 at 0.37 kW kg−1 with losing 30% of capacitance over 10,000 cycles at 10 A g−1 using 6 M KOH electrolyte. Meanwhile, the symmetrical supercapacitor shows a good specific energy of 13.18 Wh kg−1 at 0.61 kW kg−1 without losing any capacitance over 10,000 cycles at 10 A g−1 using 1 M Et4NBF4/AN electrolyte. This study is verified that the naturally available FFGF is a talented sustainable carbon source to make more economical and effective carbon electrodes for supercapacitors.

Microwave assisted growth of MnO2 on biomass carbon for advanced supercapacitor electrode materials

Microwave assisted growth of MnO2 on biomass carbon for advanced supercapacitor electrode materials