Supercapacitor Electrode Research Articles

Solar-driven induced photoelectron remember effect involved in core–shell NiCo2S4@Ni3V2O8 composite electrode with superior electrochemical energy storage for asymmetric supercapacitor

Photo-assisted supercapacitor systems offer a compelling approach to effectively harnessing both solar and electrical energy. In this study, the core–shell heterostructure NiCo2S4@Ni3V2O8 (NCS@NVO) was successfully synthesized for the development of photosensitive supercapacitor electrodes. NCS@NVO demonstrated a pronounced photoelectron memory effect under illumination, attributed to the solar-driven contributions of both NCS and NVO, as photon absorption facilitated electron-hole pair separation and transport. Compared to the specific capacitance in the dark (2292F g−1 at 1 A g−1), the capacitance of the NCS@NVO composite electrode increased dramatically to 3025F g−1 when exposed to light. Moreover, the capacitance retention rate remained remarkably high at 99.83 % after 10,000 cycles at 20 A g−1. In addition, the NCS@NVO hybrid supercapacitor achieved an outstanding energy density of 63.56 W h kg−1 under illumination, alongside a power density of 789.84 W kg−1. This study thoroughly investigated the solar-induced photoelectron memory effect in the NCS@NVO composite electrode for asymmetric supercapacitors, paving the way for the design of high-performance photosensitive nano-electrodes in advanced electrochemical energy storage applications.

Revealing the effects of functional group in organic linkers on properties of metal organic frameworks electrode and their performance in supercapacitors

The history of developing supercapacitors with increased performance is inextricably linked to the exploration and design of suitable electrode materials. Metal-organic frameworks (MOFs) have attracted intensive attention for use in high-performance supercapacitors thanks to their large specific surface area, tuneable pore sizes and crystal structure. Understanding the influence of MOF structures and properties on the performance of supercapacitors is critical to enhancing their performance. However, so far researchers have been keen on exploring metal atoms in MOFs and have ignored the effects of organic ligands, especially the functional groups thereon, on supercapacitors. In this work, we have studied the impact of organic linkers’ functional groups on the properties of MOFs and how this influences their performance as supercapacitor electrode materials. We synthesized four MOFs with different functional groups, including hydroxyl, nitride and thiol groups and characterised their physicochemical properties and their performance as supercapacitor electrode materials. Characterisation of the specific surface area shows that the BET area decreases from 980.3 m2 g−1 for the original MOF to 12.2 m2 g−1 when the thiol group is incorporated. Furthermore the –OH, –NH, and −SH functionalities reduced the charge transfer resistance (< 1 Ω) and induced more pseudocapacitance, whereas the –OH group dramatically increased the hydrophilicity of the electrode and rate performance of supercapacitors. Although the MOFs without extra function group showed the highest specific capacitance of 1495F g−1, analysis of the normalized areal specific capacitance only shows 1.5 F m−2. The MOFs with the −SH group showed the highest normalized areal specific capacitance of 26F m−2 as well as stable cycling performance of 80 % retention after 10,000 cycles.

Laser exfoliated 2D MXene for supercapacitor applications

MXenes-based compounds, particularly Ti3C2Tx, have been studied intensively as electrodes for supercapacitors due to their layered structure and high conductivity, enabling facile ion diffusion and charge transfer. However, tight restacking of the 2D layers in these materials limits their practical, accessible surface area, thereby impeding their capacity and rate capability performance. To mitigate this phenomenon, we present a new approach using a processing method based on laser beam irradiation to modify Ti3C2Tx films. We found that the laser treatment induces chemical and morphological changes, ultimately optimizing the stacking arrangement of the MXene electrodes and consequently enhancing their capacity in both neutral and acidic electrolytes. Furthermore, the laser-modified MXene electrodes demonstrate excellent rate capabilities, showing 84 % retention at extreme rates of 0.5 V compared to only 33 % of the original Ti3C2Tx electrodes. Finally, we discuss the chemical and physical changes induced by the laser treatments and their influence on the electrochemical behavior of the lasered MXene. The principles of laser exfoliation discovered in this study can be implemented in broader 2D materials for various applications.

Nanostructured nickel doped manganese oxide/polypyrrole/graphitic carbon nitride hydrogel as high-performance supercapacitor electrodes

Polypyrrole hydrogel (PH) attributing high electrical conductivity, intriguing redox properties, ease of synthesis and environmental friendliness, is a prospective electrode material for supercapacitors (SCs). This work presented details of the synthesis of pH and its binary and ternary nanocomposites. The ternary nanocomposite PPy-GCN-NMO (PGNMO), synthesized via in-situ oxidative polymerization, demonstrates an exclusive combination of morphologies, leading to excellent supercapacitive performance. The strategically chosen synergy of electric double-layer capacitance (EDLC) and pseudocapacitive materials helps in overcoming the limitation of individual elements and collectively accounts for excellent supercapacitive performance. Electrochemical studies of PGNMO electrode provides an excellent specific capacitance (Cs) of 3611 F/g at 1 A/g. Moreover, the fabricated symmetric device of PGNMO exhibits impressive Cs of 588 F/g at 1 A/g, and exceptional cycle stability with 104.3 % retention after 6000 cycles. Additionally, the device delivers appreciable specific energy of 40.1 Wh/kg at 1587.6 W/kg, positioning PGNMO to the forefront of flexible electrodes for SCs.

Electrochemical performance of rGO anchored with inorganic halide perovskite LiZrBr3 composite for effective supercapacitor electrodes

Electrochemical performance of rGO anchored with inorganic halide perovskite LiZrBr3 composite for effective supercapacitor electrodes

Synergetic Interplay of MnNi-MOF Composite with 2D MXene for Improved Supercapacitor Application

The growing demand for high-performance energy storage systems has driven the development of advanced materials to improve supercapacitor efficiency. In this study, MXene-MnNi nanocomposites are synthesized and evaluated for their potential as next-generation supercapacitor electrodes. The MnNi alloy, known for its excellent pseudocapacitive properties, is combined with MXene, a two-dimensional material recognized for its exceptional conductivity, mechanical robustness, and large surface area. The uniform dispersion of MnNi and MXene achieved through a straightforward hydrothermal method, optimizes charge transfer and enhances electrochemical performance. Electrochemical testing demonstrates that the 100 MX-MN nanocomposite exhibits a high specific capacity of 1028 C g-1 at 1 A g-1, along with excellent rate capability and long-term stability, outperforming many conventional materials. This outstanding performance is attributed to the synergistic effects of MnNi’s redox activity and MXene’s high conductivity, which together increase active site availability, accelerate ion diffusion, and maintain structural integrity. Additionally, a hybrid aqueous device is assembled using 100 MX-MN as the positive electrode and activated carbon as the negative electrode. The device delivers a maximum energy density of 87.35 W h kg-1 at a power density of 1.98 kW kg-1 and exhibits excellent capacity retention of 88 % after 10,000 charge-discharge cycles. These findings highlight the potential of MXene-MnNi nanocomposites as advanced materials for supercapacitor applications, offering a promising path for more efficient energy storage solutions in modern electronic devices.

In-situ growth of FeCo layered double hydroxide nanorods on MXene for high-performance supercapacitor electrodes

In the pursuit of clean energy solutions, supercapacitors have gained attention due to their exceptional energy storage capabilities. Layered double hydroxide (LDH), a notable material in this field, faces some challenges such as slow charge transfer speed and volumetric expansion. To tackle these issues, a novel FeCo-LDH/MXene composite was synthesized through in-situ hydrothermal growth of FeCo layered double hydroxide (FeCo-LDH) nanorods on MXene using ionic self-assembly, forming a three-dimensional (3D) composite with enhanced rate capability and cycling stability due to the synergetic coupling of MXene and LDH. The FeCo-LDH/MXene electrode significantly improves surface capacitance control performance and exhibits exceptional electrochemical performance, achieving a specific capacitance of 2058.2 F g−1 at 1 A g−1 and maintaining 1732.7 F g−1 at 10 A g−1, with 82.4 % capacity retention. Furthermore, the assembled supercapacitor delivers an energy density of 48.8 Wh kg−1 at 750 W kg−1 and 25.7 Wh kg−1 at 15000 W kg−1, demonstrating excellent rate performance, as well as 80.3 % capacitance after 5000 cycles at 2 A g−1, highlighting its durability. This advancement not only overcomes the specific capacitance challenge of MXene electrodes but also enhances the conductivity and cyclic stability of LDH, making FeCo-LDH/MXene a promising candidate for future high-performance energy storage applications.

Biopolymers as three-dimensional structural binders for nickel-cobalt sulfide supercapacitor electrodes

Ion diffusion and electron transfer are hindered by commonly used hydrophobic binders, which directly affect the electrochemical performance of the electrodes. Hydrophilic binders are selected to efficaciously solve the problem of relatively low actual specific capacitance and rate performance in the field of nickel cobalt sulfide electrode materials. In the paper, RuCoNiS electrodes were prepared using polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), xanthan gum (XG), and chitosan (CS) as binders. The surface wettability, morphological structure, specific surface area, and electrochemical performance of electrodes with different binders were analyzed by XRD, SEM, BET, CV, GCD, and EIS, etc. It's shown that the synthesis of CoNi2S is confirmed by XRD. The XPS results verify the existence of RuO2 and Ni2+/Ni3+ and Co2+/Co3+ redox couples. A cross-linked network structure is formed on the surface of the RuCoNiS by CS. The CS-RuCoNiS electrode has the largest specific surface area and microporosity. Ion migration in the electrolyte is facilitated by the excellent wettability of the CS-RuCoNiS electrode. The CS-RuCoNiS electrode reachs 1193.52 F g-1, which is 1.74 times higher than that of the PTFE-RuCoNiS electrode at 1 A g-1. The CS binder with its three-dimensional structure has the highest ionic conductivity of 2.29 × 10-4 S cm-1, a lower Rct, good cycling stability with a capacity retention of 84.3% after 5000 cycles at 200 mV s-1, and excellent rate performance of 85.6%. It can provide a practical application in supercapacitors.

Facile Synthesis of Highly Supercapacitive Mo‐doped Titanium Nanotube Arrays and Effect of Anodization Voltage

AbstractDesigning potential architectures by the modification of conventional electrode materials is an effective approach in the development of high performance supercapacitor electrodes. The present study investigated the effect of varying anodization voltages (50, 75, and 100 V) on the morphology and electrochemical properties of titanium nanotubes (TNT). Molybdenum was doped onto TNT using a simple hydrothermal procedure, followed by thermal treatment at 450 °C. The study effectively demonstrated control over the dimensions of the nanotube structure by adjusting the anodization voltage. Additionally, it was found that the tube diameters were increased due to etching during the hydrothermal treatment with the Mo precursor, which potentially enhanced the supercapacitive performance of Mo‐doped TNT. Further, structural analysis revealed that Mo doping improved both crystallinity and electrode stability. With an optimal anodization voltage of 100 V, TNT and Molybdenum‐doped TNT could exhibit capacitance value of 13.34 and 326.54 mF cm−2 respectively, at a current density of 1 mA cm−2. Furthermore, the electrode demonstrated good cyclic stability with 88% capacitance retention and 97% coulombic efficiency after 5000 cycles. An impressive energy density of 87.03 µWh cm−2 and a power density of 799.99 µW cm−2 could be achieved with this sample in an asymmetrical device.

Hierarchical structural design of cobalt sulphide nanoparticles/nickel sulphide for high-performance supercapacitors

Metal-organic framework (MOF) materials have become increasingly attractive in supercapacitor electrode research because of their regular crystal topology and tunable pore distribution. The strategy for the synthesis of the Ni3S4/Co3S4 electrode material with a layered structure was successfully devised using the layered Ni-MOF as a template and precursor. The characterisation techniques of XRD, FTIR, XPS, SEM, TEM and BET have provided confirmation of the assertion that the Ni3S4/Co3S4 composites exhibit an advanced hierarchical pore structure and considerable specific surface area. The specific capacity of the Ni3S4/Co3S4 composite is as high as 122.8 mAh g−1, and it can still maintain 72.6 % of the specific capacity after 3,000 cycles. Furthermore, the SEM morphology remains largely unchanged after cycling, which demonstrates excellent stability. Moreover, honeycomb-shape porous carbon (N-HAPC) with ultra-high specific surface area was selected as negative electrode material to fabricate a novel hybrid supercapacitor (Ni3S4/Co3S4//N-HAPC), which exhibits a broad operational voltage range of 1.6 V and superior energy density of 28.6 Wh kg−1. Simultaneously, HSCs exhibited remarkable charge-discharge stability, exhibiting a mere 17.2 % decline in capacitance stability following 7,000 GCD cycles. The combination of two Ni3S4/Co3S4//N-HAPC HSCs in series has been demonstrated to be capable of illuminating a small LED lamp, indicating the potential for their use in practical applications. Furthermore, this approach offers a novel strategy for the structural design of MOF-like materials.

Electrochemical investigation of synthesized (Mg0.21Cr0.21Mn0.21Fe0.21Cu0.16)3O4 high entropy oxide for supercapacitor electrode material

Increasing demand for energy is a significant challenge to achieve sustainable development. The advancement of energy storage device depends on the discovery of novel materials for which high entropy materials are promising candidates and have shown extraordinary electrochemical properties. This study reports the synthesis of novel high entropy oxide (HEO), (Mg0.21Cr0.21Mn0.21Fe0.21Cu0.16)3O4, using sol-gel method followed by calcination at high temperatures. Microscopic images show a homogeneous particle size distribution of 250-500 nm. The structural analysis underscores the importance of optimal stoichiometry for the formation of high-performance single-phase spinel-structured HEO. The XRD and electrochemical analysis emphasize the role of multiple elements in phase stabilization and the elements contribution to the electrochemical performance of the HEO. The oxidation and reduction behaviour of HEO with KOH electrolyte is found to be in the desired potential range of 0 V-0.4 V. The material shows the pseudocapacitive nature with an enhanced specific capacitance of 241 Fg⁻1 at 1 Ag⁻1 and retains 86% of its capacitance even after 2000 cycles, indicating excellent electrochemical stability and performance. This work highlights the potential of high entropy oxides as an advanced material for energy storage applications, offering enhanced stability and performance in supercapacitors.

A High Performance Supercapacitor Electrode Materials Based on Carbon Quantum Dots Originated from Bamboo Leaves of Southeast Sulawesi Doped with nanomagnetite Derived from Iron Sands

A High Performance Supercapacitor Electrode Materials Based on Carbon Quantum Dots Originated from Bamboo Leaves of Southeast Sulawesi Doped with nanomagnetite Derived from Iron Sands

A facile one-pot synthesis of hierarchical porous carbon for supercapacitor electrodes

This study presents a facile, environmentally friendly approach to fabricate hierarchical porous carbon for supercapacitor electrodes. The one-pot synthesis of PFO/silica/PTFE via co-pyrolysis generates ideal hierarchical porous carbon. Compared with traditional methods, this method eliminates toxic solvents and complex cleaning steps. PPC-2 obtained under the optimized activation time has the highest specific surface area (2657 m2 g−1) and a remarkable total pore volume (2.96 cm3 g−1). These properties result in a remarkable specific capacitance of 335.9–210.8 F g−1 at current densities of 0.5–10 A g−1 in KOH electrolyte. The electrochemical performance of the PPC-2 electrode in a symmetric supercapacitor device was measured in aqueous (6 M KOH) and ionic liquid (EMIM-TFSI) electrolytes. In EMIM-TFSI, PPC-2//PPC-2 provides an energy density of 48.5 Wh/kg even at a power density of 750 W kg−1. This facile one-pot synthesis method offers a sustainable and scalable approach to produce high-performance hierarchical porous carbon for supercapacitor applications.

Efficient production of activated carbons from PET for organic supercapacitor applications: A single-step approach

This study introduces a novel approach for synthesizing supercapacitor electrode materials using polyethylene terephthalate (PET), a plastic facing recycling challenges. Unlike conventional methods that involve separate carbonization and activation steps, we employ a single-step method. In this process, activated carbons are synthesized using potassium hydroxide (KOH) as an activating agent. Remarkably, the yield via the single-step method (S_PACXs) exceeds that of the two-step method (T_PACYs) by at least 1.7 times. During the single-step process, KOH forms a layer on the PET surface before activation, which leads to increased yields, higher specific surface areas, and more developed mesopores. Furthermore, S_PACXs exhibit superior specific surface areas compared to commercial activated carbon. These enhanced properties significantly improve electrochemical performance, with S_PACXs demonstrating superior performance compared to T_PACYs. Ultimately, this study validates the efficiency of the single-step method in producing high-quality activated carbon from PET, saving time and energy, and outperforming the two-step method.

A Flexible Asymmetric Supercapacitor with High-Performance and Long-Lifetime: Fabrication of Nanoworm-Like-Structured Electrodes Based on Polypyrrole-Thiosemicarbazone Complex.

A thiosemicarbazone-based iron(III) complex is prepared and used in the preparation of a supercapacitor electrode material. This electrode is produced by a solvothermal reaction of polypyrrole and the complex on carbon felt. The characterization of the complex and material is carried out using UV-vis, elemental analysis, FT-IR, XRD, BET, and TGA methods, and the surface morphology is examined using SEM technique. Because the interaction of electrode and electrolyte is of great importance in energy storage systems, as the surface area and pore volume increase, electrode ions at the electrode/electrolyte interface leak to the inner surfaces and interact with the larger surface area, which increases the charge storage performance. The electrode material, nano-worm structure, reached the highest specific capacitance value of 764.6 F g-1 at 5 mV s-1. Compared to the capacitance value of polypyrrole in its pure form, it is observed to exhibit an 187.2% increase. The highest specific capacitance value of the asymmetric supercapacitor (ASC) formed with a graphite electrode is 318.1 F g-1 at the current density of 1 Ag-1. Moreover, ASC reached a wide working potential of 1.8 V in an aqueous electrolyte and exhibited ultra-long cycle life (112%), maintaining its stability after 10000 cycles.

High-performance supercapacitor of ZnO-incorporated structurally modified g-C3N4 with circular mesoporous channels attained via a template-free approach

Abstract Here, the superior structural features of graphitic carbon nitride (g-C3N4) in combination with integrated mesoporous channels have been explored for its use as a supercapacitor electrode material. A facile template-free strategy is adopted for the preparation of ZnO-incorporated modified g-C3N4 nanocomposite, where material characterization via x-ray difraction, Fourier transfrom infrared spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy and x-ray photoelectron spectroscopy analysis revealed the presence of structurally modified g-C3N4 having uniform circular mesoporous channels with well-dispersed ZnO with strong Zn–C and Zn–N interactions. The electrical double-layer capacitance together with the pseudocapacitance of the ZnO/g-C3N4 electrode material resulted in improved performance, leading to a specific capacitance of 146.3 F g−1 at a current density of 0.5 A g−1; an increased capacitance is observed in 5000 repeated charge–discharge cycles. A symmetric coin cell supercapacitor fabricated from the material displayed an energy density of 38.8 mWh kg−1 at a power density of 4259 mW kg−1. Additionally, the long life of 6000 cycles (retaining 100% specific capacitance) exhibited by the coin cell supercapacitor further indicates the promising energy storage nature of the ZnO-incorporated modified g-C3N4 mesoporous nanoarchitecture. Real life application of the ZnO/g-C3N4-derived supercapacitor is illustrated by lighting up a green LED with a series connection of four coin cells.

Initial Study of Reduced Graphene Oxide Foams Modified by Mn and Bi as Capacitive Electrode Materials

In a view of application of porous materials in wearable electronics and self-powered systems, reduced graphene oxide (rGO) foams modified by Mn or/and Bi were produced in this study to be used as electrodes for supercapacitors. The hydrothermal method and the freeze-drying processes were used for the preparation of the materials further morphologically, elementally and structurally analyzed. Based on the electrochemical characterization, Bi-modified rGO foam was found to be more a promising material for capacitive electrodes in comparison to the other prepared materials.

Inkjet printing of silver/graphene flexible composite electrodes for high-performance supercapacitors

This study developed a silver/graphene flexible composite electrode using inkjet printing technology for high-performance supercapacitor. A rGO active layer was in-situ printed and reduced on the polypropylene non-woven fabric, and silver nanoparticles were simultaneously inserted and reduced to increase the interlayer spacing of the rGO active layer. This effectively reduced the self-stacking effect of rGO and improved the overall electrochemical performance. The successful in-situ reduction of GO and silver nitrate to rGO and silver nanoparticles was confirmed through morphological, structural, and surface chemical characterization. The 4Ag/rGO composite exhibits superior electrical conductivity, with a sheet resistance of 57.39 kΩ/sq., making it suitable for direct use as an electrode. In a three-electrode setup, these flexible composite electrodes demonstrated outstanding super capacitive performance, achieving a maximum specific capacitance of 800.30 F/g, excellent bendability, and remarkable cycle stability, with a capacitance retention of 104.9 % after over 2000 charge/discharge cycles at a current density of 0.25 mA/cm2. Furthermore, the composite electrodes exhibited a high energy density of up to 70.9 Wh/kg at a current density of 0.25 mA/cm2. The promising capacitive behavior and straightforward manufacturing process position the Ag/rGO hybrid electrodes as a potential material for future applications in next-generation flexible and wearable electronics.

Investigating the Exfoliated Hexagonal Boron Nitride Nanosheets Embedded on Bi2S3 Nanorods Designed as a Positive Electrode for Hybrid Supercapacitors

Investigating the Exfoliated Hexagonal Boron Nitride Nanosheets Embedded on Bi₂S₃ Nanorods Designed as a Positive Electrode for Hybrid Supercapacitors

Refined construction of heterophase boundary on CoCO3@Cobalt boride nanocomplexes for supercapacitor and electrocatalysis

Heterostructures comprising crystalline cores and amorphous shells are pervasively utilized in electrochemical storage and conversion due to their distinctive physical and chemical attributes. In this study, we present a novel CoCO3@Co-B nanocomposite as a tri-functional electrode for supercapacitors and alkaline water electrolysis. The material is produced via a straightforward hydrothermal process, followed by an in-situ growth treatment. The core-shell structure of crystalline CoCO₃-amorphous Co-B exhibits remarkable specific capacitance and commendable hydrogen and oxygen evolution performance. The optimized CoCO3@Co-B electrode exhibits remarkable specific capacitance (352 F g−1 @ 0.5 A g−1) and superior cycling stability (78 % @ 5 A g−1 after 10,000 cycles). Additionally, the CoCO3@Co-B//activated carbon hybrid supercapacitor device exhibits a considerable specific capacitance (42.1 F g−1 @ 0.5 A g−1). The CoCO3@Co-B electrode displays excellent OER/HER performance, with Tafel slopes of 82.6 and 116 mV dec−1, respectively, which are superior to the original CoCO3 values. This kind of active material exhibits a crystalline-amorphous contact, which reduces the energy barrier of electrochemical reactions and forms a built-in electric field, thereby increasing the number of active sites and enhancing electron transmission. As an advanced electrode material, CoCO3@Co-B holds immense potential for future development and research.