Supercapattery Electrode Research Articles

Hydrothermally etched MXene-based nanocomposite electrode for supercapattery

The requirements of energy storage devices have only been ever-increasing, from greater charge storage to faster charging to boost the energy and power densities. However, existing lithium-ion batteries are limited by their power density due to long charging duration while supercapacitors have limited energy density and higher power density. A supercapattery, a device that possesses the qualities of a battery and a supercapacitor, is being developed to achieve higher energy and power densities in a single device. MXenes are a group of promising materials to be used as electrodes in supercapatteries for their exceptional pseudocapacitive properties. Herein, Ti3C2Tx MXene was synthesized using hydrothermal-assisted etching with various in situ HF etchants, and the effects of using different cationic intercalants were explored. This approach boosts the etching efficiency of weaker etchants, ensuring the proper exfoliation of MXene precursors whilst maintaining the structural integrity of MXenes and removing the need to delaminate and intercalate them post-synthesis. Combined with graphene by sonication, the resulting wrappage of graphene around MXene could increase the electrical conductivity, promote the electrode electrolyte interaction, and improve the electrochemical performance of MXene-based electrode signification and demonstrating synergistic effects. A supercapattery was fabricated by pairing activated carbon as the capacitive electrode and optimized MXene-graphene composite (MG-21) as the pseudocapacitive electrode. The device achieved a specific capacitance of 662.02F/g and an energy density of 20.58 Wh kg−1 at 3 A/g and exhibited an excellent energy and power density of 23.02 Wh kg−1 at 0.5 A/g and 13.1 kW kg−1 at 10 A/g, respectively.

Fast and green synthesis of battery-type nickel-cobalt phosphate (NxCyP) binder-free electrode for supercapattery

Binder-free electrodes are increasingly important in energy storage technologies owing to the direct growth of active material on conducting substrates without binders, providing a shorter conduction channel for rapid electron transport. Various methods have been employed to synthesize binder-free electrodes, but most approaches often prove time-consuming, and some require elevated synthesis temperatures. Herein, a rapid and eco-friendly microwave-hydrothermal method was introduced to fabricate the battery-type nickel–cobalt phosphate (NxCyP) binder-free electrodes for supercapattery. The use of microwave accelerates heating and reduces the activation energy of the reaction, resulting in shorter synthesis time and lower reaction temperature. The NxCyP electrodes were fabricated at different parameters, such as temperature (90–200 °C), time (5–20 min), and Ni:Co precursor ratios (4:0, 3:1, 2:2, 1:3, 0:4). The optimization study was carried out via Design Expert v13 software, and the optimized parameter was the temperature of 123.5 °C, duration of 10.5 min, and Ni:Co of 2:2, namely N2C2P binder-free electrode. The N2C2P electrode exhibited larger flake- and flower-like morphologies, providing more space for electrolyte ion diffusion and a larger surface area for faradaic reactions. Consequently, it demonstrated outstanding electrochemical performance by displaying a high specific capacity (1699.7C/g at 3 mV/s), superior capacity retention, and the lowest resistances than other NxCyP electrodes. As a result, the N2C2P//AC supercapattery was created by merging it with an activated carbon (AC) electrode, showing a superior energy density (213.0 Wh/kg) and high electrochemical stability with 92.9 % retention after 3000 cycles at 10 A/g.

Sea Urchin-Like NiO-CoO Heterostructure as High-Energy Supercapattery Electrode: Laboratory Prototype to Field Application of Pouch-type Device

Sea Urchin-Like NiO-CoO Heterostructure as High-Energy Supercapattery Electrode: Laboratory Prototype to Field Application of Pouch-type Device

Layered nickel cobalt hydrogen phosphate for high performance of supercapattery electrode

Layered nickel cobalt hydrogen phosphate for high performance of supercapattery electrode

The Emerging Heteroepitaxial NiSe2/Nb2C: A Two‐In‐One Bi‐Functional Material Architecture for Electrocatalytic and Supercapattery Application

AbstractThe rational design of electrode materials is pivotal for optimizing the performance of energy storage and conversion systems such as supercapattery and electrocatalysis. In this study, a one‐step supercritical fluid synthesis is presented to craft a unique heteroepitaxial composite, incorporating nickel di‐selenide nanoparticles on niobium carbide MXene nanosheets in various ratios. The integration of 2D nanosheets enhances the kinetics of the electrode reaction process, while NiSe2 facilitates efficient charge transport in MXene. The composite demonstrated superior performance with the 1:2 ratio of NiSe2/Nb2CTx demonstrates an impressive specific capacitance of 1309 C g−1 at 2 A g−1 current density in a three‐electrode system. Furthermore, the asymmetric supercapattery, featuring NiSe2/Nb2CTx 1:2 (positive electrode) and bio‐derived activated carbon (AC) (negative electrode) achieves a gravimetric capacitance of 205 C/g at 0.5 A g−1 current density, a power density of 10,800 W kg−1 at the energy density of 64 Wh kg−1, with 90% retention after 12 000 cycles. As a catalyst for water oxidation, the NiSe2/Nb2CTx 1:2 exhibits the lowest over potential of 359 mV at the current density 10 mA cm−2 and Tafel slope of 105 mV dec−1. This investigation introduces an innovative approach for developing high‐performance supercapattery electrode materials and electrocatalysts using MXene.

Effect of cobalt hydroxide deposition on the Diffusion-Controlled contribution of cobalt Sulfide-Manganese sulfide electrode for supercapattery

The performance of supercapattery depends on the diffusion rate of the electrolyte ions on the electrode. Metal sulfides have low electrical conductivity and this will affect the active surface reacting with the electrolyte during the charge and discharge processes. In this work, cobalt sulfide-manganese sulfide (CMS) was synthesized via hydrothermal reaction. In order to enhance the channels for the diffusion of electrolyte ions, cobalt hydroxide (COH) was grown on the CMS layer. The structural and morphological of the samples were characterized and the final material was confirmed to be a petal-shaped CMS/COH nanocomposite. CMS/COH showed a higher specific capacity (777.5 C/g at 1 A/g) and a higher diffusion contribution than those of CMS, except for the rate capability. CMS/COH in supercapattery form was designed and the cycle stability was found to reach 72% after 6000 cycle repetitions.

Optimization of heating temperature on the growth of manganese sulfide nanosheets binder-free electrode for supercapattery

Optimization of heating temperature on the growth of manganese sulfide nanosheets binder-free electrode for supercapattery

HKUST-1 as a Positive Electrode Material for Supercapattery

The copper-based metal-organic framework (HKUST-1) exhibits interesting properties, such as high porosity and large specific surface area, which are useful as electrode materials for supercapattery. Herein, the HKUST-1 was synthesized through a facile hydrothermal method and exhibited a typical octahedral structure with a specific surface area of 1015.02 m2 g−1, which was calculated using the Barrett–Joyner–Halenda (BJH) method. From the three-electrode analysis, the HKUST-1 demonstrated a specific capacity of 126.2 C g−1 in 1 M LiOH. The structural fingerprint of the HKUST-1 was confirmed with Fourier-transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction spectroscopy. A supercapattery device, i.e., the HKUST-1//N-doped graphene, revealed a maximum specific power of 300 W kg−1 and a specific energy of 2.61 W h kg−1 at 1 A g−1 with 57% capacitance retention during continuous charging–discharging, even after 10,000 cycles. The HKUST-1 also demonstrated a low charge transfer resistance and a low equivalent series resistance of 7.86 Ω and 0.87 Ω, respectively, verifying its good conductivity. The prominent supercapattery performance of the HKUST-1//N-doped graphene suggested that the HKUST-1 is a promising positive electrode for supercapattery.

Scalable synthesis of binder-free hierarchical MnCo2O4 nanospikes/Ni(OH)2 nanosheets composite electrodes for high-capacity supercapatteries

Supercapatteries have received great attention in recent years due to its excellent charging storage capabilities. The effective electrochemically active surface area of the electrode is crucial in obtaining high capacity in supercapatteries. Herein, we present a scalable synthesis of binder-free hierarchical MnCo2O4 (MCO) nanospikes/Ni(OH)2 (NiOH) nanosheets (MCO/NiOH) nanocomposites for supercapattery electrode application. The MCO/NiOH nanocomposites are synthesized by the two-step hydrothermal method at low-cost without affecting nanostructures and further used as electrodes in fabricating a supercapattery. The synergistic effect of the NiOH nanosheets and MCO nanospikes helps to enhance the electrochemical charge storage performance when compared to their counterparts. The growth of NiOH nanosheets over the MCO nanospikes helps to suppress the self-discharge nature of MCO nanospikes otherwise. The MCO/NiOH//activated carbon supercapattery fabricated in the asymmetric configuration delivers a maximum specific capacity of 890C/g with a high energy density of 75.2 Wh/kg. The MCO/NiOH//activated carbon supercapattery exhibits a capacity retention of 86 % after completing 5000 charge/discharge cycles. Therefore, MCO/NiOH nanocomposite electrodes are capable candidates for the next-generation electrochemical energy storage systems.

Hydrothermally modified tin(II) sulfide binder-free battery grade electrode for supercapattery

In the initiative of diminishing the current research gap related to the limited electrochemical performance of supercapacitor, various hybrid supercapacitor combinations were introduced. However, the energy storage capacity and power are still limited. Thus, a new type of hybrid device known as supercapattery was introduced by combining a battery grade electrode with capacitive type electrode to improve the energy and power densities. In the midst of material exploration on battery grade materials suited for supercapattery, transition metal sulfides have grabbed intense attention for their excellent electrochemical properties and conductivity. Herein, a novel tin (II) sulfide (SnS) binder free electrode materials were synthesized through hydrothermal method as a battery grade material for supercapattery. In this work, the electrodes were fabricated by differing metal precursor to reducing agent ratios (1:2,1:4, and 1:6) followed by fine tuning the physio-chemical characteristics of SnS by differing hydrothermal temperature. The synthesized materials were structurally characterized using X-ray diffraction analysis. The surface morphology and particle size were investigated through field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). The SnS fabricated using ratio 1:4 at 150 °C exhibited fascinating specific capacity/specific capacitance (325.20Cg−1/668.45Fg−1) with 89.73% rate capability. The SnS was then combined with activated carbon (AC) to produce supercapattery. The fabricated supercapattery demonstrated fascinating stability of 98.61% over 15,000 cycles with maximum energy and power density of 8.77 Wh kg-1 and 3,095.20 W kg−1, respectively.

Highly efficient and stable layered AgZnS@WS2 nanocomposite electrode as superior charge transfer and active redox sites for energy harvesting device

Transition metal dichalcogenides (TMDs) are considered to be excellent candidates in energy storage applications because of their 2D structure and astonishing electrochemical features. Still, the poor stability of these materials limits their way to becoming perfect supercapattery electrode materials. Therefore, researchers are synthesizing their hybrids with other electrode materials to minimize these drawbacks. Herein, the tungsten disulfide (WS2) nanosheets were combined with hydrothermally synthesized silver zinc sulfide (AgZnS) nanostructures to design a hybrid electrode material for high-performance energy storage devices with superior charge transfer and abundant active redox sites. The highly porous structure of AgZnS@WS2 was analyzed by BET which confirmed the enhancement in ion diffusion and the reversible redox mechanism. The composite was analyzed using SEM, XRD, RAMAN, and XPS to study its morphological, structural, and compositional properties. The effect of different electrolytes was studied to estimate the electrochemical characteristics. The AgZnS electrode, upon characterization in 1 M KOH, revealed the maximum specific capacity (Qs) of 1209.06 Cg−1 at 1.8 Ag−1. While the AgZnS@WS2 hybrid electrode exhibited the Qs of 2516.58 Cg−1 at the same current density (js) benefitting from the features of both materials. The AgZnS@WS2 hybrid electrode employed in a supercapattery revealed a maximum Qs of 388.8 Cg−1 at 1.2 Ag−1. The device delivered a maximum energy density of 86.4 Wh kg−1 and a notable power density of 4987.6 W kg−1. The superb 95 % cycle stability and strong electrochemical performance of AgZnS@WS2 are the results of the highly conductive structure and synergistic effect of hybrid material for high surface area with quick ion diffusion. The astonishing features of hybrid material are suitable and encouraging for its industrial applications as supercapattery electrode material.

Carbon dots integrated into nickel-cobalt hydroxide as superior electrode for supercapattery

Nickel hydroxide (Ni(OH)2) is one of the most valuable electrode materials for supercapacitors. Owing to the low stability and conductivity of Ni(OH)2 electrode, the preparation of a fast and high-stability Ni(OH)2 electrode is a significant challenge. Nickel hydroxide integrated with cobalt and carbon dots (CDs-Co/Ni(OH)2) as a high performance electrode has been prepared by cathodic electrodeposition for supercapattery in this work. Compared with unintegrated Ni(OH)2 electrode or carbon dots integrated Ni(OH)2 electrode, the introduction of Co greatly improves the stability of the Ni(OH)2 electrode, particularly at high current density. The as-obtained CDs-Co/Ni(OH)2 electrode presents a high specific capacitance of 338.6 mAh/g at 5 A/g and an extraordinary cycling stability with 1000 cycles even under a high current density of 40 A/g (retaining 84.6%). Besides, the CDs-Co/Ni(OH)2 electrode exhibits an energy density of 281.2 Wh/kg at a power density of 57.2 kW/kg. Such a glorious stable CDs-Co/Ni(OH)2 electrode may provide significant insight into future multifarious electronics and electrified vehicle applications.

Rational design of a novel MnO2-FeSe2 nanohybrid with nanowires/cubic architecture as promising supercapattery electrode materials

A promising MnO2-FeSe2 nanohybrid is reported for the first time by the wet-chemical assisted route and directly utilized as a synergistic electrode for supercapattery applications. The optimized electrochemical performance of the MnO2-FeSe2 nanohybrid is realized when tested for capacitive signature and active redox reactions. Testing for capacitive signature and active redox reactions reveals the MnO2-FeSe2 nanohybrid's enhanced electrochemical performance. The MnO2-FeSe2 nanohybrid has a greater capacitance due to the cyclic voltammetry's bigger enclosed loop area, higher current response, and longer discharge time frame. Also, due to the synergistic impact between the two pseudocapacitive materials in the three-mode assembly, the least resistance in the impedance plot was attained when compared with MnO2 and FeSe2 electrodes. Based on these striking results, MnO2-FeSe2||AC||KOH supercapattery displayed a highly stable performance (95.3% retention) at the highest current response when run for 10,000 repeated discharge-charge cycles. It achieved a high energy of 55.39 Wh/kg at the power delivery of 4320 W/kg by expanding the upper voltage cutoff to 1.7 V in an aqueous medium. Our research paves a new way to develop metal selenide nanohybrid electrodes with conventional pseudocapacitive materials that could efficiently boost the electrochemical properties of the parent materials owing to the synergistic effect. The acquired results displayed the potential growth of MnO2 and FeSe2 nanohybrid as the future active materials for sustainable and clean energy storage devices.

Anomalous electrochemical performance of binary silver–strontium phosphate-based electrode material in supercapattery

Mesoporous silver strontium phosphate (SSP) was synthesized through a facile hydrothermal technique and utilized as a positive electrode for supercapattery. Material's morphology, crystallinity, elemental composition, and homogeneity were carried out through SEM, TEM, XRD, EDS, XPS, and EDS mapping. Various electrochemical characterizations were performed in three as well as two electrode assemblies to ensure the ability of the material towards electrochemical charge storage. In fact, three-electrode results explore that the material possesses excellent performance in terms of specific capacity, lower series resistance, and negligible charge transfer resistance. After a conclusive three electrode assembly findings, an asymmetric supercapacitor was assembled by utilizing SSP as a positive electrode and as a counterpart carbon nanotube (CNT) as a negative electrode. This hybrid device reveals excellent electrochemical performance and was able to deliver a specific capacity of 240.0 C/g. Indeed, not only higher capacity was delivered by this device, nevertheless, its performance was remarkable in terms of high energy density and excellent power density. Besides, the rate capability for the supercapattery was estimated from GCD which was ∼77% at the highest current density of 12 A/g. The stability has a significant role in energy storage devices and was analyzed by charging and discharging the device, and the results demonstrate the outstanding specific capacity retention of 86.68% after 5000 cycles. Likewise, the device successfully holds coulombic efficiency of 95.79% by the end of 5000 charge-discharge cycles. Our analysis reveals that this material possesses remarkable energy performance which makes it applicable for future supercapattery devices.

Rapid synthesis of nickel‑copper phosphate electrode by microwave-assisted hydrothermal reaction for supercapattery

This study reports the fabrication of binder-free nickel‑copper phosphate (NCP) battery-type electrode via microwave-assisted hydrothermal method for the first time. This fabrication method involved microwave heating which significantly reduced the reaction time compared to the conventional hydrothermal method. The NCP electrodes with different precursor ratios (Ni:Cu of 4:0, 3:1, 1:1, 1:3, and 0:4) were fabricated at 90 °C for 12.5 min. Among all NCP binder-free electrodes, Ni3-Cu-P electrode (Ni:Cu of 3:1) exhibited superior electrochemical performance by showing the highest specific capacity of 1030.8 C/g and areal capacity of 0.72 C/cm2 at 3 A/g, and the lowest charge transfer (25.9 Ω) and ion diffusion resistances. These can be explained by the fact that Ni3-Cu-P electrode had a small-sized microsphere electrode material with an amorphous structure deposited on the nickel foam. The small-sized microsphere provided a larger surface area for faradaic reaction. Besides, the amorphous structure offered more electrochemical sites for faradaic reaction. Therefore, it was selected as the battery-type electrode for supercapattery. The Ni3-Cu-P//AC supercapattery delivered a higher energy density of 51.6 Wh/kg at 2.25 kW/kg power density, and outstanding stability with 91.3 % capacity retention after 3000 cycles.

Deconvolution of capacitive and diffusive charge/lithium storage in lyophilized NiCo2S4–NiCo2O4 composite for supercapattery and lithium-ion battery

Freeze-dried (lyophilized) NiCo2S4–NiCo2O4 composite as an electrode for supercapatteries and lithium-ion batteries.

A comprehensive study of binder polymer for supercapattery electrode based on activated carbon and nickel-silicon composite

Current trends suggest that as manufacturing and energy demand increase, there will be a greater consumtion for energy storage, requiring its utilization for days, weeks, or even months in the future. Recent studies also need to be conducted on binders that could support electrode performance, considering that binders are also a crucial component of the electrochemical processes in cells. In this study, activated carbon-based supercapacitor electrodes were fabricated using three different binders: PVDF, SBR, and LA133. With a gravimetric capacitance and power density of 52.57 Fg−1 and 92.64 W.kg−1, and a lifetime up to 87.23% after 1000 cycles, AC/CB LA133 has the best performance. LA133 was used as a binder to generate a Ni/Si composite as a battery electrode combined with the AC/CB LA133 supercapacitor to fabricate a supercapattery. This clearly shows that when a suitable binder such as LA133 is used, the electrochemical performance could be improved.

1,2,4-Triazole (Htrz) functionalised 2D-manganese-organic framework (UPMOF-5) as a battery-type electrode for supercapattery

Metal-organic frameworks (MOFs) have attracted a lot of attention in the field of energy storage and conversion due to their unique properties, including large specific surface areas, adjustable pore sizes and stable porous structures. Herein, we report a novel porous Mn-based MOF that was prepared through a facile solvothermal method using 1,2,4-triazole (Htrz) organic linker in the presence of N, N’-dimethylacetamide (DMA) as a solvent. The novel [Mn(Htrz)(DMA)Br] denoted as UPMOF-5 crystallised in a monoclinic P21 space group showing a two-dimensional (2D) structure and a large BET surface area of 1725 m2/g. For the first time, the synthesised manganese-1,2,4-triazolate framework (UPMOF-5) was used as an electrode in supercapattery device assembly. Impressively, a battery-graded nature was shown in the three-electrode assembly of the UPMOF-5, which had a decent specific capacity of 160.17 C/g at 0.4 A/g. The designed supercapattery device with UPMOF-5 as a positive electrode and activated carbon as a negative electrode delivered a good specific capacity of 132.40 C/g at 0.4 A/g with 24.77 Wh/kg of specific energy at 538.91 W/kg of specific power. After 10,000 cycles, the device showed promising capacity retention of 70.3 %. The structural stability and porous character of UPMOF-5 are credited with the decent electrochemical performance.

Engineering redox active sites enriched 3D-on-2D bimetallic double layered hydroxide electrode for supercapatteries

The functionalization of structural nanoengineered battery-type electrodes has aided the emergence of supercapattery (SCp) subclass, which enables a wide range of applications. Herein, our research work provides a platform for two-step fabrication of nanoengineered 3D-on-2D structure as a promising approach to obtain high-performance battery-type electrodes. The hierarchical 2D NiCo bimetallic LDH NC(12)40 electrode was fabricated using electrodeposition, while the nanoengineered 3D ZIF-67 on 2D LDH electrode was achieved via pseudomorphic replication techniques. The fabricated 3D-on-2D NC(12)40-30 electrode reveals a maximum areal capacity of 1044 mC cm−2 at a current density of 4 mA cm−2 in 6 M KOH electrolyte. Furthermore, NC(12)40-30//AC was integrated as a SCp device, achieving a maximum specific capacitance of 63 F/g and maximum specific energy and power of 20.5 W/h/kg and 8522.7 W/kg, respectively, with improved capacitance retention (85%) even after 10,000 cycles. Thus, the assembled SCp coin cell displays 18-LED illumination in four different commercial LED colors, indicating the viability of the battery-type electrode for SCp development.

Supercapattery performance of carbon nanofibers decorated with poly(3,4-ethlenedioxythiophene) and cobalt oxide

Supercapattery epitomizes the next level of energy storage technology which demonstrates the pros of a supercapacitor and a battery. In this work, we developed a positive electrode of supercapattery comprised of porous functionalized carbon nanofibers (pfCNFs) as a template for the electrodeposition of poly(3,4-ethylenedioxythiophene) (PEDOT) and incorporation of cobalt oxide (Co3O4) through hydrothermal and annealing. Interestingly, the composite displays a flower-like structure observed on the fibers. The functionalized carbon nanofibers/poly(3,4-ethylenedioxythiophene)/cobalt oxide (pfCNFs/PEDOT/Co3O4) exhibited obvious redox peaks demonstrating its battery type property with high specific capacity (Csp) and specific capacity (Cs) of 849.65 F g-1 and 679.72 C g-1, respectively. As for the real application, the positive electrode of pfCNFs/PEDOT/Co3O4 and nitrogen-doped graphene as a negative electrode was assembled with a polyvinyl alcohol/potassium hydroxide gel used as a separator. The pfCNFs/PEDOT/Co3O4//NDG displayed specific energy of 14.54 Wh kg-1 and specific power of 1726.96 W kg-1 at 2 A g-1. In addition, the device also exhibited remarkable cycling stability with 106.26% capacitance retention over 2000 cycles revealing its prospect as an electrode for supercapattery.