High-performance Supercapacitor Electrode Research Articles

Three-Dimensional Polypyrrole-Decorated CuCo2S4 Nanowires Anchored on Nickel Foam: A Promising Electrode for High-Performance Supercapacitors.

The exploitation of high-performance supercapacitors is crucial to promote energy storage technologies. Benefiting from the three-dimensional conductive micronanostructures and high specific capacity of the PPy@CuCo2S4@NF (polypyrrole/copper cobalt sulfide/nickel foam) composite electrode, this electrode exhibits a high specific capacity of 1403.21 C g-1 at 1 A g-1 and a capacitance retention of 85.79% after 10,000 cycles at 10 A g-1. The assembled PPy@CuCo2S4@NF//AC aqueous hybrid supercapacitor (AHSC) reveals a wide operating potential window of 1.5 V and achieves a high specific capacity of 322.52 C g-1 at 1 A g-1 and a capacitance retention of 86.84% after 15,000 cycles at 10 A g-1. The AHSC also exhibits a high power density of 733.69 W kg-1 at an energy density of 67.19 W h kg-1, surpassing those of previously reported spinel-based supercapacitors. Ex situ X-ray diffraction and X-ray photoelectron spectroscopy results show that the CuCo2S4 spinel structure changes to CuS2 and CoS2 cube structures, and the oxidation states of Cu and Co increase during charging and discharging processes. Density functional theory calculations suggest a superior conductivity for CuCo2S4 compared to that for CuCo2O4, demonstrating that CuCo2S4 has superior electrochemical performance. These findings attest to the considerable potential of the spinel materials for advanced energy storage applications.

Preparation of high-performance supercapacitor electrode with nanocomposite of CuO/NCNO flower-like

Due to the importance of energy storage systems based on supercapacitors, various studies have been conducted. In this research CuO, NCNO and the flower like CuO/NCNO have been studied as a novel materials in this field. The resulte showed that the synthesized CuO nanostructutes have flower like morphology which studied by FE-SEM analisis. Further, the XRD pattern confirmed the crystalline properties of the CuO/NCNO nanocomposite, and the Raman verified the functional groups and vibrations of the components of CuO/NCNO nanocomposite. In a two-electrode system at a current density of 4 A/g, the capacitance, power density, and energy density were 450 F/g, 3200 W/kg, and 98 Wh/kg, respectively. The charge transfer resistances of CuO and NCNO/CuO electrodes obtained 8 and 2 Ω respectively, which show that the conductivity and supercapacitive properties of nanocomposite are better than pure components. Also, the stability and low charge transfer resistance are other advantages obtained in a two-symmetrical electrode investigation. The stability investigation showed that after 3000 consecutive cycles, only 4% of the initial capacitance of the CuO/NCNO electrode decreased.

Cobalt phosphide/nickel–cobalt phosphide heterostructured hollow nanoflowers for high-performance supercapacitor and overall water splitting

In this work, a novel CoP/NiCoP heterostructure with hollow nanoflower morphology is designed and constructed. Benefiting from the hollow nanoflower morphology and tuned electronic structure, the heterostructured CoP/NiCoP hollow nanoflowers are demonstrated as both high-performance supercapacitor electrode materials and superior bifunctional electrocatalysts in overall water splitting. The CoP/NiCoP delivers a high capacitance of 1476.6 F g−1 at 1.0 A g−1 and shows enhanced rate capability. The constructed asymmetric supercapacitor achieves a high energy density of 32.4 Wh kg−1 at 800.5 W kg−1 and high power density of 16.5 kW kg−1 at 20.0 Wh kg−1. The CoP/NiCoP hollow nanoflowers are also proven to be remarkable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalyst which achieves the current density of 10.0 mA cm−2 under an overpotential of 110.4 mV for HER and 310.7 mV for OER with superior stability in alkaline solution. In addition, the constructed CoP/NiCoP||CoP/NiCoP cell with CoP/NiCoP as both cathode material and anode material only requires 1.63 V @ 10.0 mA cm−2 for overall water splitting. This study sheds lights on the rational design and construction of bimetallic phosphides for both supercapacitor and overall water splitting.

Enhancement of electrochemical properties of electrodes for high performance supercapacitors by electrodeposition of CoSe on hydrothermally prepared CuCo2O4

CuCo2O4 is a kind of promising electrode material for supercapacitors, while single CuCo2O4 electrodes suffered the limitation in structure stability and the inferior electrochemical activity. Herein, CoSe covered urchin-like CuCo2O4 electrodes for high performance supercapacitors were successfully prepared in this paper, and it’s proved that the core-shell structure of CoSe@CuCo2O4 could greatly improve the stability and electrochemical performances. On the one hand, the synergistic effect between CoSe and CuCo2O4 can effectively change the energy band structure to make the band gap disappear, resulting in the increase of electrical conductivity, and the electrochemistry properties are greatly improved. For example, the specific capacitance at 1 A g−1 was greatly increased from 310 C g−1 of CuCo2O4 to 1047.2 C g−1 of CoSe@CuCo2O4. Particularly, when the composite electrode of CoSe@CuCo2O4 with core-shell structure was applied to the asymmetric supercapacitors, a relatively excellent energy density of 87.28 W h kg−1 at a power density of 1280 W kg−1 was obtained. On the other hand, CoSe can be served as an efficient armor to protect the inner CuCo2O4 by the core-shell structure, so the stability was dramatically enhanced from the 52.8 % of CuCo2O4 after 2000 cycles to 95.7 % after 4000 cycles.

Rapid cold plasma synthesis of cobalt metal–organic framework/reduced graphene oxide nanocomposites for use as supercapacitor electrodes

Metal–organic frameworks (MOFs) are recognized as a desirable class of porous materials for energy storage applications, despite their limited conductivity. In the present study, Co-MOF-71 was fabricated as a high-performance supercapacitor electrode at ambient temperature using a fast and straightforward, one-pot cold plasma method. A supercapacitor electrode based on Co-MOF@rGO was also synthesized by adding reduced graphene oxide (rGO) during processing to increase the capacitance retention and stability after 4000 cycles from 80 to 95.4%. The Co-MOF-71 electrode provided a specific capacitance (Cs) of 651.7 Fg−1 at 1 Ag−1, whereas the Co-MOF@rGO electrode produced a Cs value of 967.68 Fg−1 at 1 Ag−1. In addition, we fabricated an asymmetric device (Co-MOF@rGO||AC) using Co-MOF-rGO as a high-rate positive electrode and activated carbon (AC) as a negative electrode. This hybrid device has a remarkable specific energy and power density. The combination of MOFs with reduced graphene oxide (rGO) in a cold plasma environment resulted in the formation of a three-dimensional nanostructure composed of nanosheets. This nanostructure exhibited an increased number of electroactive sites, providing benefits for energy storage applications.

Constructing metal organic framework derived manganese cobalt layered double hydroxide nanosheets on Ni foam as cost-effective binder-free electrodes of high-performance supercapacitors

A vital aspect of energy storage devices is the development of novel materials with excellent electrical conductivity and rational structures. In combination with alkaline electrolytes, the manganese-cobalt layered double hydroxide (MnCo-LDH) cathode material has long been recognized as a highly desirable cathode material. Nevertheless, the synthesis of MnCo-LDH is time-consuming and required high temperatures. Therefore, it is important to find simple routes for the synthesis of MnCo-LDH. Herein, we propose a synthesis of metal organic framework (MOF)-derived MnCo-LDH nanosheets on conductive nickel foam (NF) for the supercapacitor (SC) application. The CoMOF decorated NF was fabricated by simple precipitation method, and then it was converted to MnCo-LDH by etching process at 80 °C for 5 min (MnCo-LDH/80 °C). The MOF-derived MnCo-LDH/80 °C electrode provides large accessible regions for electrolytes, low charge transfer resistance, and rich electroactive sites. Therefore, the MnCo-LDH/80 °C electrode demonstrates preferable energy storage property with a high areal capacitance of 2.62 F/cm2 at 20 mV/s. In this study, an asymmetric supercapacitor (ASC) is constructed using MnCo-LDH/80 °C and activated carbon (AC) on NF as the positive and negative electrodes, respectively. The optimized MnCo-LDH//AC device provides the maximum energy of 0.116 mWh/cm2 at the maximum power density of 2.49 mW/cm2. Added to that, the ASC has excellent cyclic stability with 78% as the capacitance retention and Coulombic efficiency of 94.3% after 5000 charge-discharge cycles.

Hierarchical 3D flowers of 1T@2H-MoS2 assembled with an array of ultrathin nano-petals for high-performance supercapacitor electrodes

Hierarchical 3D flowers of 1T@2H-MoS2 assembled with an array of ultrathin nano-petals for high-performance supercapacitor electrodes

Rational design of one-dimensional skin-core multilayer structure for electrospun carbon nanofibers with bicontinuous electron/ion transport toward high-performance supercapacitors

The fast transport of electrons and ions within electrodes is crucial to the final electrochemical properties. Herein, we have developed a unique ultra-long one-dimensional (1D) skin-core multilayer structure based on electrospun carbon nanofibers mainly through a facile Stöber method combined with resorcinol–formaldehyde resin, which not only achieves bicontinuous electron/ion transport during the charge/discharge process, but also provides large surface area for ion adsorption. Particularly, controlling the number of active layers as well as regulating the active sites in layer both can obviously improve capacitive properties. Benefiting from the synergistic effects of the desirable architecture, such the rational-designed skin-core structural carbon nanofibers as supercapacitor electrode can deliver a high specific capacitance up to 255 F g−1 at 0.5 A g−1, favorable rate capability with 89% capacitance retention of initial capacitance at 8 A g−1, and excellent cycling stability with nearly 93% capacity retention after 10,000 cycles at 2 A g−1. Furthermore, the as-assembled symmetric supercapacitor devices also present a maximum energy density of 8.77 Wh kg−1 at 0.25 kW kg−1 and a maximum power density of 3.70 kW kg−1 at 6.74 Wh kg−1. Such skin-core carbon nanofibers provide an effective strategy to design high-performance supercapacitor electrode for the next-generation energy storage devices.

Carbon nanofiber-supported elongated square bipyramid-like MnWO4 composite electrodes for high-performance battery-type supercapacitors: Enhanced electrochemical performance via synergistic effect

Battery-type electrode materials known for high electrochemical performance are commonly paired with carbon-based materials, which have recently gained attention for their potential application in supercapacitors. These carbon-based materials offer the potential for comprehensive energy storage properties along with excellent cycle life. In this study, a carbon nanofiber (CNF)-based elongated square bipyramid-like manganese tungstate (MnWO4; MnW) composite was synthesized via a simple and cost-effective solid-state reaction followed by an impregnation method. The main objective was to understand the synergistic effects of varying the content of CNF in the reaction on the formation of two different composites (MnW-CNF@L and MnW-CNF@H) and their physicochemical and electrochemical properties were thoroughly examined and compared to those of the MnW. Pure composites have a high crystalline nature with bipyramid-shaped microstructures anchored on the one-dimensional (1D) tubular CNF backbone, as confirmed by the structural and morphological analysis. In the context of the battery-type supercapacitor, the specific capacity is 2-fold higher for MnW-CNF@L (235.3 mAh g−1/848.1 C g−1) and 4-fold higher for MnW-CNF@H (451.3 mAh g−1/1624 C g−1) compared to the MnW (11.8 mAh g−1/402.6 C g−1) electrode at a current density of 1 A g−1. In addition, the MnW-CNF@H composite electrode delivered 96% capacity retention when current density increased 20-fold and exhibited outstanding cyclic stability of 95% initial capacity retention after 5,000 cycles. A solid-state hybrid supercapacitor was fabricated using the battery-type MnW-CNF@H composite electrode as the cathode and activated carbon (AC) as the anode. The MnW-CNF@H//AC HSC device configuration resulted in remarkable performance metrics, displaying a high energy density of 48.9 Wh kg−1 at 1018.2 W kg−1. The exceptional performance of this composite can be attributed to the synergistic effect among redox centres of Mn, W, and CNF. This work broadcasts a simple and cost-effective approach for designing high-performance supercapacitors, contributing to the development of sustainable energy storage systems.

Constructing highly stable and biomimetic supercapacitor materials of 2D MoS2 coupled with NiCoLDH @chitosan carbon microsphere

Due to the growing demand for clean and renewable energy, the effective utilization of renewable resources in energy storage and has been concerned. And high specific capacitance and stable electrochemistry for energy storage devices are challenging to develop. Learning from unique structure of goniastrea coral, we design to construct three-dimensional layered conductive electrodes material made of MoS2@chitosan carbon spheres (MNCCS) composite. The NiCoLDH nanosheets construct on the surface of conductive chitosan carbon spheres to effectively form open permeable channels and rich conductive networks, improves the efficient energy storage and electrochemical stability. MoS2 is strongly coupled with NiCoLDH nanosheets through heterointerface, which resembles tentacles on the surface of coral, exposing more active sites to efficiently trap ions. Besides, the obtained material possesses favorable heterojunction interface and defects, which provide sufficient available electroactive sites and numerous storage charge area. Hence, The MNCCS presents an outstanding specific capacitance of 2605.9 F g−1 at 1 A g−1. Notably, a supercapacitor fitted with MNCCS electrode and CCS electrode achieves high specific capacitance (234.4 F g−1 at 1 A g−1), the maximum energy density of 77.0W h kg−1 at highest power density of 667.4W kg−1, along with the excellent cycling stability of 90.8% retention over 10,000 cycles. This work provides a new perspective for fabricating high-performance and stable supercapacitors electrode material for clean energy storage.

Silver/molybdenum metal-organic framework derived Ag2MoO4 nanoparticles as novel electrode for high-performance supercapacitor

Novel silver/molybdenum bimetallic metal-organic framework (AgMo-MOF) was synthesized using the solvo-hydrothermal method and then converted to Ag2MoO4 nanoparticles by calcination process. The cubic spinel structure of Ag2MoO4 was confirmed by XRD. The valence states of Ag, and Mo are +1, and + 6, respectively, according to the XPS spectra. The specific surface area was evaluated to be 24.52 and 56.58 m2 g−1 for the AgMo-MOF and Ag2MoO4, respectively, using BET analysis. The optical band gap of Ag2MoO4 was estimated to be 3.38 eV. The GCD analysis revealed the superior specific capacitance of 652.5 and 1468.7 F g−1 at 1 A g−1 for AgMo-MOF/NF and Ag2MoO4/NF electrodes, respectively. The cyclic stability after 5000 cycles at 20 A g−1 revealed that the AgMo-MOF/NF and Ag2MoO4/NF electrodes are stable with capacitance retention of 86 % and 90 %, respectively. Furthermore, Ag2MoO4//AC asymmetric supercapacitor devices provide a terrific energy density of 72.1 Wh kg−1 at 1123.6 W kg−1 and capacitance retention of 88 % over 5000 cycles.

Nanostructured Fe-Substituted LaMnO3 Perovskites as a High-Performance Electrode for Supercapacitors

With the rise in eco-friendly energy needs, supercapacitors have become an essential option for energy storage devices. For this purpose, new and efficient electrode materials are required for use in supercapacitors with higher durability and longer storage lifespan. For this, transition metal oxides are preferred, owing to their high capacitance values, for energy storage in supercapacitors. In this context, LaMn1-xFexO3 (x = 0.0, 0.33, 0.66, and 1.0) are presented here with a better electrochemical response, prepared following sol−gel auto-combustion route to optimize the influence of Fe substitution at Mn-site in LaMnO3. X-ray diffraction technique confirms the formation of the orthorhombic phase for both LaFeO3 and LaMnO3. Cyclic voltammetry was performed at a constant potential window of −0.2 to 0.4 V and varying scan intervals (0.01−0.2 Vs−1). The oxidation/reduction peak occurrences revealed the pseudocapacitive behavior and the apparent Nyquist plot showed less charge transfer resistance. Thus, marvelous results expose the synthesized composition LaMn1-xFexO3 at x = 0.0, 0.33, 0.66, and 1.0, a promising material for the electrodes.

Controllable synthesis of MnSe2/Co0.85Se nanosheets as a binder-free electrode for high-performance asymmetric supercapacitors

With the increasingly serious environmental pollution and depletion of natural resources, it is necessary to develop efficient and environmentally friendly energy storage equipments to alleviate the problem of resource shortage. In this study, a novel MnSe2/Co0.85Se (MCSe) electrode was successfully prepared using a simple, green and environmentally friendly electrodeposition method. The MCSe electrode exhibited good electrochemical performance, and possesses a high specific capacity (Cs) of 1380C/g at a current density (CD) of 1 A/g. An asymmetric supercapacitor (ASC) assembled using a positive electrode (the MCSe electrode) and a negative electrode (active carbon (AC) electrode) delivered a high specific energy density (Es) of 49.63 Wh/kg at a specific power density (Ps) of 750 W/kg. Hence, this study provides a new approach for designing metal selenides for energy storage and conversion.

Novel 2D CeO2 nanoflakes as a high-performance asymmetric supercapacitor electrode material

Enhancing the performance and durability of benchmarked metal catalysts using nanostructured non-metallic materials is an active area of research that is exciting from both a fundamental and an application perspective. The 2D CeO2 nanoflakes are characterized using structural and electrochemical techniques. Galvanostatic charge-discharge (GCD) revealed that the material delivers a specific capacitance of 1801 F/g at 1 A/g, among the best-reported values for transition and rare earth metal oxide electrode material. Due to its nanoflake-like structure, the sample has a modest surface area (12.6 m2/g). Asymmetric supercapacitor device (CeO2//AC) fabricated delivered an energy density of 57.6 Wh/kg and a power density of 771 W/kg with 83 % capacitance retention after 1000 cycles in 3 M KOH. This study reveals that CeO2 is a promising electrode material for energy storage applications.

Four-stage chemical treatment of spent pot lining carbon for titanium oxide doped high performance supercapacitor electrode material

Obtaining carbon materials in a sustainable way and applying them in energy storage systems is attracting more attention. Spent potlining (SPL) which is a carbon-rich waste produced in electrolytic cells of aluminium smelters can be a potential source of carbon for engineering applications. However, SPL is hazardous in nature and needs to undergo chemical treatment for most engineering applications. In this study, a four-step procedure was adopted to remove sodium fluoride (NaF), cryolite (Na3AlF6), alumina (Al2O3), calcium fluoride (CaF2), sodium aluminate (NaAl11O17) and silica (SiO2) from the SPL. The adopted treatment processes proved effective as Energy Dispersive X-ray (EDX) and X-ray Diffraction (XRD) results showed no traces of the major impurities after the treatment. The treated carbon-rich SPL was activated using NaOH to obtain activated SPL (ASPL). The ASPL was doped with TiO2 to form ASPL-TiO2 (1:1), ASPL-TiO2 (3:1) and ASPL-TiO2 (2:1) electrodes. The electrode materials were tested using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The ASPL, ASPL-TiO2 (1:1), ASPL-TiO2 (3:1) and ASPL-TiO2 (2:1) demonstrated specific capacitance of 180.2 F/g, 279.1 F/g, 536.7 F/g, and 203.2 F/g at 10 A/g respectively with high stability over 1000 cycles. The present study was designed to determine the suitability of using chemically treated SPL as an alternative source of carbon for supercapacitor applications and this was achieved as the material exhibited an improved charge storage capacity.

Co-electrodeposition hybrid reduced graphene oxide and nickel-cobalt selenide nanosheets on silicon nanowires for high-performance supercapacitor

Due to inherent compatibility with IC technology, 3D silicon is prone to build a skeleton for the energy storage electrodes. Herein, a unique 3D hierarchical core-shell electrode was first developed with silicon nanowire arrays (SiNWs), metal selenide (TMSe) and reduced graphene oxide (RGO) nanosheets, where SiNWs decorated with Ni particles (Si/Ni) served as the conductive core and co-electrodeposited hybrid nickel-cobalt selenide (NCSe) and RGO nanosheets (NCSe-RG) functioned as the high capacitive outer shell. Owing to the synergy effect between NCSe and RGO, high-speed electron transport channels of Si/Ni, and abundant electroactive sites of porous NCSe layer, the synthesized Si/Ni/NCSe-RG electrode delivered a large capacitance of 2268 F g−1 (1973 mF cm−2) at 1 A g−1 which was higher than most reported silicon-based electrodes, and an excellent rapid-charging capability (1540 F g−1 at 30 A g−1). Furthermore, a solid asymmetric supercapacitor (SC) was prepared by using Si/Ni/NCSe-RG as the positive electrode, demonstrating an excellent energy density of 53.23 Wh kg−1 at the power density of 800 W kg−1. Our results suggest that high-performance SC electrodes can be engineered with TMSe and 3D silicon with a simple and time-saving method.

Construction of hierarchical porous two-dimensional Zn-MOF-based heterostructures for supercapacitor applications

Recently, two-dimensional metal-organic frameworks (2D MOFs) are drawing increasing attention in energy storage area. Specially, hybrid 2D MOF-based heterostructures have greatly promoted the development of MOF-based electrode materials. However, the underutilization of both abundant active sites and high surface area causes 2D MOFs poor performance and thus restricts their practical application. Herein, to shorten the ion transport paths and enhance the ion diffusion ability, mesopores were introduced into 2D Zn-MOF sheets to construct a hierarchical porous Zn-MOF-based heterostructure. The energy-storage mechanism in the heterostructures was deeply investigated and the importance of the introduced-mesopores on enhancing the electrochemical behaviors was confirmed. With the optimized design, the obtained Meso-Zn-MOF@rGO-PBA delivered outstanding electrochemical performance, including a high capacitance (292.8 F g−1 at 0.2 A g−1), an excellent rate capacity (268.1 F g−1 at 5 A g−1) and a good cycling stability (83.2 % retention after 2000 cycles). Furthermore, the practical applicability of Meso-Zn-MOF@rGO-PBA was researched by assembling an asymmetric supercapacitor using activated carbon as the other electrode, achieving a satisfied specific capacitance of 54.9 F g−1 with an energy density of 19.5 Wh kg−1 (1 A g−1). Our observation provides a strategic design idea for high-performance supercapacitor electrode materials.

Rationally Engineered Ultrastable Three-Dimensional (3D) Conjugated Microporous Polymers Containing Triptycene, Tetraphenylethene, and Benzothiadiazole Units as Exceptional High-Performance Organic Electrodes for Supercapacitors

Rationally Engineered Ultrastable Three-Dimensional (3D) Conjugated Microporous Polymers Containing Triptycene, Tetraphenylethene, and Benzothiadiazole Units as Exceptional High-Performance Organic Electrodes for Supercapacitors

Nitrogen-doped graphene quantum dots/co-doped PANI binary nanocomposites as high-performance supercapacitor electrode materials

In this paper, a suitable and high-performance electrode material for practical applications was developed using a simple two-step approach. Here, we report that nitrogen-doped graphene quantum dots with co-doped polyaniline (N-GQDs-PANI) were fabricated by in situ polymerization as supercapacitor electrodes and that the effect of the amount of N-GQDs in the electrode material on the electrochemical performance was investigated. The integration of N-GQDs into co-doped PANI structure prevented the agglomeration of PANI and enabled the fabrication of N-GQDs as thin film on the surface. This modification improved the charge transfer of the N-GQDs-PANI electrode compared to N-GQDs and pure PANI electrodes, allowing it to exhibit superior electrochemical performance. The N-GQDs-PANI electrode has a specific capacitance of 503 F/g at a current density of 5 A/g with a capacitance retention of about 91.9 % after 10000 charge/discharge cycles.

Flexible free standing electrodes based on laser-irradiated PVC/PVDF/AuNPs for the development of high performance supercapacitor electrodes

Free-standing PVC/PVDF/Au NPs composite have been successively synthesized and irradiated to laser at various times 2, 5, and 15 min. The as-prepared composite films have been investigated by FTIR, XRD, FESEM, UV, DSC, and TGA. FTIR and XRD techniques proved the complexation between PVC/PVDF and Au NPs. Optical properties like band gap energy and Urbach tail are calculated. Also, thermal analysis affirmed that thermal stability is increased by the addition of Au NPs. The prepared films were employed as flexible substrates for supercapacitors applications. The electrochemical features of prepared composite films were measured using varieties of electrochemical techniques such as cyclic voltammetry (CV), as well as galvanostatic charge-discharge (CD) in three electrode configurations. PVC-PVDF/Au NPs that were subjected to 15 min laser radiation delivered the highest specific capacitance of (645.3 F/g at a current density of 1 A/g), improved rate capacitance (63.2 % of original value is retained at a current density of 10 A/g.