High-performance Supercapacitors Research Articles

Nickel foam supported CuO/Co3O4/r-GO is used as electrode material for non-enzymatic glucose sensors and high performance supercapacitors

Nickel foam supported CuO/Co3O4/r-GO is used as electrode material for non-enzymatic glucose sensors and high performance supercapacitors

MnOOH nanorods decorated with CeO2 nanoparticles as advanced electrode for high-performance supercapacitor

The development of novel composite electrode materials is essential to fabricating supercapacitors with high specific capacitance and good stability. In this study, MnOOH nanorods adorned with CeO2 (CeMn composites) have been satisfactorily synthesized through in-situ growth of tiny CeO2 nanoparticles using hydrothermal treatment. SEM images revealed that the granular CeO2 particles are adhered to the surfaces of nanorod-shaped MnOOH. XRD analysis confirmed the CeMn composites maintain the crystal structure of MnOOH and CeO2 with high purity. The EDS elemental mapping images demonstrated that Mn, O, and Ce elements are homogenously dispersion distributed in the CeMn composites. The supercapacitive performance of the MnOOH and CeMn composites pasted onto the Ni foam was evaluated determined through electrochemical measurements. The Ce0.05Mn1 (Ce/Mn molar ratio of 0.05/1) as a supercapacitor electrode exhibited an excellent specific capacitance of 857.62 F/g at 1 A/g, which is higher than the values for the MnOOH. Moreover, the prepared Ce0.05Mn1 still could retain good cycling stability over 3000 charge/discharge cycles. This study presents a feasible route to develop high-performing supercapacitor electrode materials.

Preparation of lignite-based porous carbon for high performance supercapacitor and the correlation between pore structures and electrochemical performance

Porous carbon exhibits considerable potential in energy storage field due to its remarkable electrical conductivity and adjustable pore structure. Nevertheless, the electrochemical performance of the material will be significantly impacted by its unreasonable pore structure. In this study, lignite was used as raw material to prepare lignite-based porous carbon by one-step activation method and the pore structure was optimized to improve its electrochemical performance and expand the utilization of low-rank coal. The results reveal that the porous carbon prepared at 600 °C has a higher specific surface area (940 m2 g−1) and a suitable pore structure (71 % mesopore), which enable adequate charge storage and fast transport of electrolyte ions, resulting in excellent electrochemical performance. In the three-electrode system, the lignite-based porous carbon exhibits a notable specific capacity of 331 F g−1 at the current density of 0.5 A g−1 and retains 96.4 % initial capacitance after undergoing 10,000 cycles. When assembled into a symmetrical supercapacitor, the device provides an energy density of 6.5 Wh kg−1 at a power density of 250 W kg−1. Even after 10,000 cycles, the capacitance retention rate is kept at 91 %, and the coulombic efficiency remains close to 100 %. These findings demonstrate that cost-effective porous carbon can be prepared by a simple route using lignite, hence exhibiting promise as electrode materials for high-performance supercapacitors.

Ni-In-oxalate nanostructure as electrode materials for high-performance supercapacitors

Energy storage technologies play a crucial role in addressing the intermittent characteristics of renewable energy sources, improving the stability of electrical grids, and decreasing the release of greenhouse gas emissions. In this study, we presented nickel indium oxalate (Ni1-xInxC2O4) as a promising material with potential applications in the field of electrochemical energy storage. The as-prepared Ni-In- oxalate sample was subjected to different physical characterizations, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Regarding the electrochemical energy storage capability, the Ni1-xInxC2O4 electrode material exhibited a specific capacitance of 835 F g-1 (417.5 C g-1) at 1 A g-1. The incorporation of nickel into the indium oxalate nanoplates enhances their electrochemical performance. The presence of nickel in the nanoplates generated from substrate, improving the overall conductivity of the material and enhances its electrochemical reactions, thus leading to improved energy storage capabilities.

Three-dimensional allium flower-like iron-cobalt sulfide nanomaterials for high-performance supercapacitors

Supercapacitors with their improved performance in high energy density and long-term cycling stability have been the growing trend in recent years for fulfilling the demand of efficient energy storage systems. Herein, we report morphology-controlled three-dimensional (3D) Allium flower-like bimetallic iron-cobalt sulfide (3D-FeCoS AF) nanomaterials on nickel foam (NF) electrodes using a single-step electrochemical deposition strategy. The self-standing bimetallic 3D-FeCoS AF nanostructures show good performance towards the supercapacitance applications. The 3D-FeCoS AF nanostructures delivered a specific capacitance of ∼375.7 F g−1 at a current density of 1.0 A/g. The possible electron cloud delocalization among the FeS nanostructures through d-bands leads to the lower charge transport resistance at the 3D-FeCoS AF electrode–electrolyte interfaces and improved conductivity. The 3D-FeCoS AF electrode demonstrated excellent specific capacity and rate performance in a 2.0 M KOH electrolyte. Owing to their enormous electrochemical active surface area (ECSA) and distinctive 3D nanosheet morphology, the present 3D-FeCoS electrode holds great potential for the fabrication of additional transition metal sulfide materials for excellent supercapacitor performances. The findings of this study suggest promising prospects for the utilization of these materials in practical supercapacitance applications.

Recent advances in heteroatom doped transition metal sulfides for high-performance supercapacitors

Supercapacitors have been well focused on, due to the advantages of fast charging/discharging, high power density, long service time and safety. Electrode materials determine the performance of supercapacitors. Serving as a kind of battery-type materials, transition metal sulfides have been received more attentions for high redox activity and high specific capacity. Controllable synthesis of metal sulfides determines their microstructure and composition, which is the basis for developing new materials. Therefore, this review firstly introduces existing synthetic methods of transition metal sulfides, including hydrothermal/solvothermal method, template method, electrodeposition method, sol-gel method, co-precipitation method, exfoliation/intercalation method and solid state method. The preparation process, principle, advantages/shortages of each method and related examples are highlighted. Taking controllable synthesis as the main line, recent advances of heteroatom doped metal sulfides and their application in supercapacitors are introduced in the second section. According to the type of dopants, all doped metal sulfides are divided into two parts: nonmetal doped metal sulfides, including B, N, F, O, P and Se, and metal doped sulfides, including alkali metal, precious metal, rare earth metal and transition metal. The research progresses about materials preparation, structure feature and supercapacitance performance are summarized. At last, current issues and future prospects in the field of heteroatom doped metal sulfides are proposed. It is anticipated that the review will provide guiding ideas or strategies for developing high-performance metal sulfides electrode materials.

Hydrangea-like NiMn Layered Double Hydroxide Grown on Biomass-Derived Porous Carbon as a High-Performance Supercapacitor Electrode

Hydrangea-like NiMn Layered Double Hydroxide Grown on Biomass-Derived Porous Carbon as a High-Performance Supercapacitor Electrode

N-doped hierarchical porous carbon derived from corncobs by molten salt method for high-performance supercapacitors

The use of biomass-derived carbon in supercapacitors is widespread due to the advantages of low price and environmentally friendly. However, these materials often exhibit limitations regarding specific capacity and cycle characteristics. Therefore, in this study, N-doped hierarchical porous carbon (NPC) was obtained by one-step LiCl/KCl molten salt carbonization activation using biomass waste corncobs as the carbon precursor and urea as an N doping medium. By modifying the ratio of molten salt to precursor, NPC-10 exhibits an optimal microstructure including specific surface area and pore characteristics. Furthermore, the suitable degree and type of N doping provide additional reactive active sites for energy storage. The combination of N doping and hierarchical porous improves the energy storage capacity of the NPC. The NPC-10 has a specific capacity of 278.2Fg-1 at 1Ag-1 and maintains 169.5Fg-1 at 100Ag-1. This study offers a novel approach to the synthesis of hierarchical porous carbon materials derived from biomass for the storing energy in supercapacitors.

Hierarchical porous sulfur self-doped lignin carbon derived from full component utilization of black liquor for high-performance supercapacitors

Hierarchical porous sulfur self-doped lignin carbon derived from full component utilization of black liquor for high-performance supercapacitors

Investigating the Effect of Carbon Nanotubes Decorated SmVO4-MoS2 Nanocomposite for Energy Storage Enhancement via VARTM-Fabricated Solid-State Structural Supercapacitors Using Woven Carbon Fiber.

Traditional supercapacitors are cumbersome and need separate enclosures, which add weight and reduce space efficiency. In contrast, structural supercapacitors combine energy storage with load-bearing materials, optimizing space and weight for automotive and aerospace applications. This study investigates the synthesis of SmVO4-MoS2 and SmVO4-MoS2-CNT nanocomposites, focusing on optimizing CNT concentration in SmVO4-MoS2-CNT for high-performance supercapacitors. The optimal concentration of SmVO4-MoS2-CNT is identified and used to fabricate structural supercapacitor devices via the vacuum-assisted resin transfer molding (VARTM) technique. The results indicate that the specific capacitance of Sm-Mo-C5, using a three-electrode system, reached 1.01Fcm-2 at a current density of 2.187mAcm-2. The performance improvement is attributed to the synergistic interaction among SmVO4, MoS2, and CNTs, collectively enhancing conductivity and active site availability. The practical application of this study is demonstrated by synthesizing Sm-Mo-C5 on woven carbon fiber (WCF) and subsequently fabricating a structural supercapacitor device (SSD) using the VARTM. The SSD, produced via VARTM, exhibited a specific capacitance of 0.287Fcm- 2 at a current density of 2Acm-2. The device showcased exceptional cyclic stability, maintaining 72.5% of its initial capacitance after 50,000 charge-discharge cycles. Additionally, it achieved a maximum energy density of 79.86Whkg-1 at a power density of 1017.69Wkg-1.

Regulating and Unraveling Electrochemical Behavior of Hierarchically‐Densifying Mesoporous Apocynum Carbon for High performance Supercapacitor

AbstractThe commercial carbon‐based supercapacitor with high power ability (~5 kW kg−1) is still unable to fulfill the superhigh power requirement of specific power‐type equipments (>20 kW kg−1), such as rail transit facilities, electromagnetic and laser equipment. To unravel the structure‐activity relationship and electrochemical behavior of power‐type densifying carbon is a key to overcome the contradiction of the suitable mesoporous ratio and highly‐densifying features toward the superhigh power requirement. Here, we built the hierarchically‐densifying mesoporous apocynum carbon (HDMC) with optimized mesoporous ratio by hierarchical activation method. More importantly, both the isothermal desorption/adsorption and high‐pressure mercury intrusion porosimetry methods were employed to synergistically uncover the microscopic surface carbon network stacking mechanism and the macroscopic carbon skeleton densification assembly mechanism. The highly‐densifying skeleton features and high mesoporous ratio properties were proved to be co‐existed in HDMC, which is in favour of rapidly ion/electron transferring toward electrochemically‐improving power behavior of HDMC. A combination of high tap density (0.387 g cm−3) and ideal microporous‐mesoporous system (23.1 % proportion of mesoporous) have taken this HDMC to provide a super‐high power density (33.5 kW kg−1) and a high volume power density (9.37 kW L−1) for HDMC‐based supercapacitor, more than those of commercial YP‐50F (14.9 kW kg−1 @ 4.63 kW L−1). Therefore, this work provides a synergistic strategy to incorporate the properties of mesoporous and densifying, and reveals its electrochemical behavior toward the further application of power‐type supercapacitors.

Porous and high specific surface area carbon material derived from ginkgo leaves for high-performance symmetric supercapacitors

Carbon materials have the advantages of large surface area, high conductivity and stable chemical properties, and are widely used in the field of electrochemical energy storage. However, carbon materials currently have some problems such as high cost, complicated process and poor electrochemical performance. The development of low cost, environmental friendly and high specific capacitance porous carbon materials is of great significance for large-scale production and application. In addition, renewable, low-cost biomass materials are ideal precursors for the preparation of porous carbon materials. In this work, porous carbon materials were synthesized using ginkgo leaves as carbon source and KHCO3 as activator. The effect of activator mass on the structure and composition of porous carbon was studied in detail. The results show that when 3 g activator is added, the prepared carbon material (GCK-3) has a specific surface area of up to 2640 m2 g−1 and a rich hierarchical pore structure (including micro, medium and large pores). In addition, the carbon material retains a certain amount of the heteroatoms of the biomass itself, which can generate additional pseudocapacitance. Due to the advantages of composition and structure, GCK-3 shows good electrochemical performance and rate performance. A symmetric supercapacitor assembled from two identical GCK-3 electrodes has an energy density of 13.7 Wh kg−1 and exhibits good cycle stability with a capacitor retention rate of 100 % after 10,000 cycles. The green and low-cost carbon source precursor, simple synthesis method and excellent electrochemical properties all indicate that ginkgo leaf derived carbon materials have great application prospects.

Stimuli-Triggered Diffusion Dynamics in Single-Junction Electrode for Enhanced Supercapacitor Performance: Insights into the Carrier Relaxation and Charge Transfer Kinetics.

Study of external triggers add new chemistry to energy storage research by virtue of controlling diffusion and charge transfer dynamics. Herein, we have chosen a model system, Ag2S-BiVO4 (Ag2S-BVO), for examining the diffusion dynamics upon light illumination using electrochemical and carrier relaxation studies. Favorable band alignments in the single-junction electrode lead to optimized carrier movement across the interfaces, developing a partial positive charge on the electrode, thereby enhancing the mass-transport of electrolyte ions toward the active electrode for efficient charge storage. Synergistic coupling across the heterojunction provides a high areal capacity of 338 mF cm-2 at 0.5 mA cm-2 under light illumination by facilitating the dominant diffusion characteristics within system. In addition, the Ag2S-BVO-based asymmetric supercapacitor exhibits an areal energy density of 32 mWh cm-2 @ 700 mW cm-2 under illumination. This study provides a strategy to tune the capacitive and diffusion contributions for high-performance light-sensitive supercapacitor devices.

Unique hollow fries-like NiCo-LDH material derived from NiCo-MOF with significant advantages of high-performance supercapacitors

Unique hollow fries-like NiCo-LDH material derived from NiCo-MOF with significant advantages of high-performance supercapacitors

One-Step Synthesis of NiCo-LDH@Ni(OH)2 Heterostructure Foams on Biomass-Derived Porous Carbon for High-Performance Supercapacitors.

Layered double hydroxides (LDHs) have attracted much attention as pseudocapacitor supercapacitor electrodes because of their high theoretical specific capacity. However, LDHs have drawbacks such as poor electrical conductivity, and their specific capacities are lower than the theoretical values. In this work, NNCLDH@OPC electrodes are constructed via in situ synthesis of heterostructure foams (NNCLDH) consisting of NiCo-LDH and Ni(OH)2 on pomelo peel-derived porous carbon (OPC) through a one-step solvothermal method using ZIF-67 as a template. Owing to the synergistic effect of the 3D nanofoam structure and the multicomponent heterostructure as well as the conductive porous carbon support, the NNCLDH/OPC exhibited ultrahigh electrochemical performance as well as excellent cycling stability: a specific capacity of 3290 F g-1 at 1 A g-1 and a capacitance retention of 77.8% after 4000 cycles at a current density of 10 A g-1. In addition, the assembled NNCLDH@OPC//OPC asymmetric supercapacitor (ASC) has a maximum energy density of 51Wh kg-1 with a power density of 812W kg-1 and a maximum power density of 16kW kg-1 at a current density of 20 A g-1. These results demonstrate the significant application potential of NNCLDH/OPC composites in supercapacitor electrodes.

In situ synthesis of Cu(OH)2 and carbon nanotube electrodes: A promising approach for high-performance one-dimensional flexible supercapacitors

Amidst the rapid surge in electrical device utilization, there is an urgent need for advanced power supply solutions. Flexible supercapacitors, renowned for their remarkable electrochemical properties, emerge as a promising remedy. This study employs in situ techniques on copper wire (CW) to obtain active materials for both the electrodes. The positive CW@Cu(OH)2 electrode, synthesized through vapor-phase reaction between CW and NH3·H2O, yields copper hydroxide (Cu(OH)2) nanosheets via an alkali-assisted oxidation process. Comparative analysis of CW@Cu(OH)2 electrodes under varying reaction conditions revealed that the Cu(OH)2 nanosheets, characterized by their small size and high distribution density on CW, significantly enhance electrochemical performance. The optimized CW@Cu(OH)2 electrode achieved a specific capacitance of 195.7 mF cm−2. This in situ growth method effectively prevents active material detachment, resulting in electrodes with minimal internal resistance. Carbon nanotubes (CNTs), also synthesized in situ via chemical vapor deposition on CW, serve as the active materials for the negative electrode. Assembled in parallel, the flexible supercapacitor, CW@Cu(OH)2//KOH-PVA//CW@CNTs, achieves a specific capacitance of 1.59 F cm−3 at a current density of 0.1 A cm−3, with an energy density of 0.496 mWh cm−3 at a power density of 15 mW cm−3. Demonstrating robust capacitance retention across varying current densities and diverse bending angles, this supercapacitor signifies a versatile and stable power storage solution.

Engineering ZnNi-LDH with improved wettability by N-direct-doping for high-performance supercapacitor

Reforming transition metal layered double hydroxides (LDH) is an unswerving desire to enable them high-performance electrode materials for supercapacitors. In this work, an efficient strategy was proposed to boost the charge-storage performances of ZnNi-LDH grown on NF by direct-doping of N species using 2-methylimidazole as N source via one-step hydrothermal method. N-doping endowed them with ultrathin nanosheets, abundant active sites and improved wettability, which were conducive to expediting the electron/ion transport and reaction kinetics, and thus greatly enhancing the electrochemical properties. Density functional theory (DFT) calculations further verified that in-situ N-direct-doping regulated the electronic structure and reduced the OH− adsorption energy, which effectively promoted the ion adsorption capability and intrinsic wettability, which made the electron/ion transport more rapid. As a result, the optimal N-doped ZnNi-LDH (N/ZnNi-LDH(3)) showed a high specific charge of 1265.7 C g−1 at 1 A g−1, much higher than that of the pristine ZnNi-LDH (406.8 C g−1 at 1 A g−1). Furthermore, the hybrid supercapacitor was assembled with N/ZnNi-LDH(3) and activated carbon as the positive and negative electrodes, respectively, which delivered a satisfactory energy density of 64.6 Wh kg−1 at 850 W kg−1 and excellent long-term cycling lifetime. The strategy provided a feasible route for optimizing the energy storage performance.

High-performance supercapacitors utilising PEDOT composite electrodes; synthesis, characterisation and electrochemical performance analysis

High-performance supercapacitors utilising PEDOT composite electrodes; synthesis, characterisation and electrochemical performance analysis

Microwave assisted activation of silkworm excrement for fast adsorption of methylene blue and high performance supercapacitor

The activated carbon (AC) with an exceptionally high surface area was made of silkworm excrement (SE) by microwave-assisted KOH activation (MAKA). It was investigated for the potential applications in methylene blue (MB) adsorption and a supercapacitor electrode. The effect of activation time on the AC properties and performance was studied. The physical and chemical properties of the as-prepared samples were analyzed by FE-SEM, TEM, N2 adsorption, and Raman spectroscopy. Remarkably, the AC with the largest specific surface area (SAs) of 2530.3 m2g−1 was produced by partial carbonization of SE at 400 °C (SE400-5) and then activated for only 5 min. The large SAs is attributed to the abundance of micro-pores, leading to the enhanced MB absorption performance, as equilibrium was reached within 10 min at 25 ppm of MB concentration. The maximum MB adsorption capacity for SE400-5 was 902.56 mg g−1. The adsorption isotherms revealed that the Langmuir model best fits the empirical data (R2 ≥ 0.9813), indicating monolayer adsorption. The kinetic model fitted well to the Pseudo-second-order (PSO) (R2 ≥ 0.9691). CV, GCD, and EIS measurements also evaluated the electrochemical properties of all samples. The electrodes were made without the addition of conductive material. The SE400-5 also had the lowest total resistance and highest total effective capacitance, which resulted in its highest specific capacitance (Cs) of 322 F g−1 at 0.5 A g−1. The capacitive retention of SE400-5 remained as high as 98% even after 10,000 cycles at 10 A g−1. These results demonstrate that SE is a viable source of AC for MB adsorption and a supercapacitor electrode.Graphical abstract

Rational engineering of meso-macroporous structured carbon materials for revealing capacitive mechanism

The tailorable meso-macroporous structure of hierarchical porous carbon (HPC) is an essential key to improve ion diffusion dynamics and microporous accessibility for capacitive material. However, few studies focus on the capacitive mechanism of meso-macroporous proportion of HPC. Herein, a regionally selective dissolution and pyrolysis strategies are deployed to tailor the proportion of meso-macropores in facial mask-derived HPC through adjusting the oxalic acid concentration in hydrothermal process in this contribution. The obtained HPC show increasing meso-macroporous volumes of 0.04, 0.12, and 0.40 cm3 g−1, corresponding to the oxalic acid concentrations of 0.2, 0.5, and 1.0 g/50 ml, respectively, while the microporous structures remain similar. Electrochemical results show that with increasing proportion of meso-macropores, the specific capacitances of HPC decrease from 386.9 to 276.5 and 220.3 F g−1 at current density of 1 A g−1, and decrease from 216.7 to 181.1, and 133.1 F g−1 at 50 A g−1. CV fitting results indicate that a small number of meso-macropores can enhance the surface-controlled capacitive contribution, improving the accessibility of micropores and faradaic pseudocapacitive reactions. The optimized HPC-based supercapacitor delivers a high energy density of 11.5 Wh kg−1 at a power density of 125 W kg−1 in KOH electrolyte and a maximum energy density of 49.4 Wh kg−1 at 225 W kg−1 in Na2SO4 electrolyte with long cycle stability, suggesting that the rational engineering of meso-macroporous proportion in HPC uncover news insights into developing high performance supercapacitor.