High-performance Supercapacitor Devices Research Articles

Simultaneous reduction of carbon dioxide and energy harvesting using RGO-based SiO2-TiO2 nanocomposite for supercapacitor and microbial electrosynthesis

Nowadays, developing a simple, economical, and scalable approach for producing energy storage and harvesting devices remains challenging. Herein, we developed a mesoporous RGO-SiO2-TiO2 nanocomposite for the electroreduction of carbon dioxide through microbial electrosynthesis and high-performance supercapacitor device. An electrode containing Si/Ti oxide nanoparticles and a layer of RGO coated on carbon felt containing RGO-SiO2-TiO2 NCs demonstrated stable photocurrents 2.1 times higher than a bare carbon felt electrode and acetate production of 3.21 mM/d with a coulombic Efficiency of acetate 78% and a current density 2.7 A/m2, which was metabolized into acetate from HCO3- by cultivated anaerobic bacteria. The RGO-SiO2-TiO2 NCs-based supercapacitor achieved a maximum energy density of 35 Wh/kg at 630 W/kg power density, and after 10,000 cycles, it retained 84% capacitance stability at 10 A/g with 180 F/g at 1.25 A/g. This method presents a straightforward, cost-effective approach for mitigating CO2 emissions and generating energy harvesting devices.

Design and construction of low resistance copper doped polyaniline electrode with ultrahigh loading density for high performance supercapacitor applications

Polyaniline is a promising material for the development of high performance flexible supercapacitor devices. However, the loose structure of polyaniline materials and the high intermolecular transport impedance between molecular chains remain significant technical barriers, particularly at high loading density. In this study, we developed a copper ion doped polyaniline electrode (Cu-PANI@CC) on carbon cloth using a simple one-step in-situ electrochemical deposition method. The structure and electrochemical properties of this electrode were investigated via different testing techniques. Benefiting from the catalysis and regulation of copper ions between PANI molecular chains, the electrode demonstrated a relatively low internal resistance at high loading densities (> 10 mg cm−2). Moreover, this electrode exhibited specific capacitance of 3.49 F cm−2 at 5 mA cm−2 and capacitance retention of 83.31% at 50 mA cm−2. Two Cu-PANI@CC electrodes were used to fabricate a symmetrical capacitor, which exhibited remarkable cycling stability and wide operating temperature range. The excellent electrochemical performance of the Cu-PANI@CC electrode highlights the potential for use in high-performance supercapacitor devices.

Exploring the synergistic effect of palladium-doped molybdenum phosphate as an electrode material for high-performance asymmetric supercapacitor device

In this research, we synthesized molybdenum phosphate (MoP) and palladium-doped MoP on a porous Ni-foam substrate using a one-step hydrothermal method for supercapacitor electrodes. Various techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, and field emission scanning electron microscopy were employed to investigate the structural and morphological properties of the synthesized materials. The MoP and MoP-Pd samples exhibited hexagonal rod-like structures, which contributed to their porosity and high electrochemical activity. Electrochemical testing revealed that MoP demonstrated an areal capacitance of 3.8 F/cm² (0.60 mA/cm²). With the addition of Pd to MoP, the capacitance increased to 4.05 F/cm² (0.62 mAh/cm²) at a current density of 4 mA/cm² in a 2 M KOH electrolyte. The charge storage kinetics of both MoP and MoP-Pd indicated a dominant diffusion-controlled contribution, attributed to the Faradic redox process. The MoP-Pd electrode displayed excellent stability, retaining about 90.7% of its initial capacitance, and exhibited a coulombic efficiency of 100% over 15,000 cycles. Furthermore, we assembled an asymmetric device (ASD) using MoP-Pd as the positive electrode and activated carbon (AC) as the negative electrode. This ASD demonstrated an areal capacitance of 0.44 F/cm² (0.21 mAh/cm²), accompanied by an energy density of 0.178 mWh/cm2 and a power density of 1.28 mW/cm² within a potential window of 0–1.8 V, measured at an applied current of 3 mA. These results highlight the significant supercapacitive potential of MoP, further enhanced by the addition of Pd, suggesting its promising application as an electrode material in energy storage systems.

Building Block Engineering toward Realizing High-Performance Electrochromic Materials and Glucose Biosensing Platform.

The molecular engineering of conjugated systems has proven to be an effective method for understanding structure-property relationships toward the advancement of optoelectronic properties and biosensing characteristics. Herein, a series of three thieno[3,4-c]pyrrole-4,6-dione (TPD)-based conjugated monomers, modified with electron-rich selenophene, 3,4-ethylenedioxythiophene (EDOT), or both building blocks (Se-TPD, EDOT-TPD, and EDOT-Se-TPD), were synthesized using Stille cross-coupling and electrochemically polymerized, and their electrochromic properties and applications in a glucose biosensing platform were explored. The influence of structural modification on electrochemical, electronic, optical, and biosensing properties was systematically investigated. The results showed that the cyclic voltammograms of EDOT-containing materials displayed a high charge capacity over a wide range of scan rates representing a quick charge propagation, making them appropriate materials for high-performance supercapacitor devices. UV-Vis studies revealed that EDOT-based materials presented wide-range absorptions, and thus low optical band gaps. These two EDOT-modified materials also exhibited superior optical contrasts and fast switching times, and further displayed multi-color properties in their neutral and fully oxidized states, enabling them to be promising materials for constructing advanced electrochromic devices. In the context of biosensing applications, a selenophene-containing polymer showed markedly lower performance, specifically in signal intensity and stability, which was attributed to the improper localization of biomolecules on the polymer surface. Overall, we demonstrated that relatively small changes in the structure had a significant impact on both optoelectronic and biosensing properties for TPD-based donor-acceptor polymers.

All-in-one supercapacitors with high performance enabled by Mn/Cu doped ZnO and MXene

Here, we report the development of high-performance supercapacitor devices using manganese-doped zinc oxide nanowires (Mn-doped ZnO NWs) and copper-doped zinc oxide nanoparticles (Cu-doped ZnO NPs) as a positive electrode with MXene as a negative electrode. Both transition metal (TM)-based electrodes were used separately with MXene, and the performance was tested. When used in combination with MXene as a second electrode, TM-ZnO samples displayed a major increase in the supercapacitors’ performance. The highest-performance supercapacitor recorded values of 151 F/g specific capacitance along with 84 Wh/kg energy density and a power density of 75 kW/kg. Electron paramagnetic resonance and photoluminescence spectroscopy of Mn/Cu-doped ZnO reveals intrinsic and extrinsic defect signals, which were discussed and attributed to the enhancement of the capacitive performance. The presence of the aforementioned defects optimizes the intrinsic properties and boosts the reaction kinetics, thus providing increased electrochemical activity and superior supercapacitor device performance.

MoSn2Se4-decorated MXene/functionalized RGO nanohybrid for ultrastable supercapacitor and oxygen evolution catalyst

Multifunctional MXene-based electrode with good electrocatalytic performance in oxygen evolution reaction as well as superior supercapacitor performance is rare so far. In this study, Mo and/or Sn selenides were grown on a template of MXene (Ti3C2Tx)/amine functionalized reduced graphene oxide (NH2-RGO) binary composite material via facile hydrothermal method. The presence of Mo and Sn metal centers has a crucial significance to increase the reactive sites over Ti3C2Tx/NH2-RGO nanosheets. Further, the Ti3C2Tx/NH2-RGO binary structure provides a conducting matrix to the metal selenides and prevents their agglomeration tendency. Superior electrocatalytic activity was obtained from Ti3C2Tx/NH2-RGO/MoSn2Se4 electrocatalyst with an onset potential of 1.3 V [vs. Reversible Hydrogen Electrode (RHE)], lower overpotential (η10) of 50 mV, large electrochemically active surface area, and smaller Tafel slope of 55.9 mV/dec with durable electrocatalytic performance. The assembled asymmetric supercapacitor device using our synthesized material as cathode showed excellent performance with high specific capacitance (120.2 F/g), large energy density (42.7 W/h/kg), and ultrastability with 97% capacitance retention after 10,000 charging–discharging cycles. The prepared ternary composite has been synthesized for the first time and has also performed better than the previous reports of its kind. This work provides an overall insight into designing an electrode material for both efficient oxygen evolution as well as high performance supercapacitor device.

A comprehensive overview of MXene‐based anode materials for univalent metal ions (Li+, Na+, and K+) and bivalent zinc ion capacitor application

AbstractThe excellence of MXene electrode material for high performance battery and supercapacitor devices represents immense possibility to construct MXene‐based metal ion capacitors (MICs) with a high energy/power density and long cyclic life. Various reports indicate that the MXene and its composites/heterostructures can be a suitable anode material to assemble MICs in non‐aqueous/aqueous electrolytes. The pillaring of MXenes with Sn4+, Fe2O3, TiO2, Fe3O4/C, SnO2, NaNbO3, MoS2, CNTs, graphene, etc. effectively alleviates restacking of nanosheets and provides large interlayer spacing as well as additional active sites. Formation of three‐dimensional network with porous structures and heteroatom doping are also advantageous for high performance electrode materials. Results indicate that the MICs can achieve a high energy density (up to 241 Wh kg−1) like rechargeable battery, a high power density (up to 25,000 W kg−1) like supercapacitor, and a satisfactory cyclic stability. This article reviews state‐of‐the art MXene‐based anode materials for various MICs. After a brief introduction about the MICs, its storage principle, historical background, and insights of the MXene synthesis, property, and storage mechanism, the article summarizes/evaluates the electrochemical performance of various MICs assembled by the MXene‐based anode materials. Finally, we outline challenges/future prospects of the MICs using MXene‐based anode materials.

Free-standing reduced graphene oxide/carboxymethylcellulose-polyaniline (RGO/CMC-PANI) hybrid film electrode for high-performance asymmetric supercapacitor device

This work demonstrates a facile and effective strategy for the preparation of a reduced graphene oxide/carboxymethylcellulose-polyaniline (RGO/CMC-PANI) hybrid film electrode. Specifically, through the hydrogen bonding interaction between -OH of CMC molecules and -NH2 of aniline monomer, PANI grows in an ordered manner on the surface of CMC, which effectively alleviates the structural collapse of PANI during the continuous charge/discharge process. After compounding with RGO, CMC-PANI bridges adjacent RGO sheets to form a complete conductive path, and opens the gap between RGO sheet layers to obtain fast ion channels. As a result, the RGO/CMC-PANI electrode exhibits excellent electrochemical performance. Moreover, an asymmetric supercapacitor was fabricated using RGO/CMC-PANI as the anode and Ti3C2Tx as the cathode. The results show that the device has a large specific capacitance of 450 mF cm−2 (81.8 F g−1) at 1 mA cm−2 and a high energy density of 140.6 μWh cm−2 at a power density of 749.9 μW cm−2. Besides, 87.3 % initial capacitance and 100 % good coulombic efficiency can be maintained even after 20,000 GCD cycles. Therefore, the device has a broad application prospect in the field of new-generation microelectronic energy storage.

Facile Synthesis of Polyacrylic Acid/Graphene Oxide Composite Hydrogel Electrolyte for High-Performance Flexible Supercapacitors

The development of hydrogel electrolytes plays a critical role in high-performance flexible supercapacitor devices. Herein, a composite hydrogel electrolyte of polyacrylic acid (PAA) and graphene oxide (GO) has been successfully prepared, where the oxygen-containing functional groups of GO may crosslink and form hydrogen bonds with carboxyl on the molecular chain of PAA, thereby significantly enhancing the mechanical properties of a PAA-based gel electrolyte. The tensile strength increases from 4.0 MPa for pristine PAA gel to 6.1 MPa for PAA/GO composite gel, with the elongation at break rising from 1556% to 1950%. Meanwhile, GO promotes the transportation of electrolyte ions, which are favorable for enhancing the ionic conductivity of the PAA hydrogel. As a result, the assembled supercapacitor based on PAA/GO composite hydrogel electrolyte shows enhanced capacitance retention of 64.3% at a large current density of 20 A g−1 and excellent cycling stability over 10,000 cycles at 5 A g−1. Furthermore, the fabricated flexible supercapacitor devices could maintain outstanding electrochemical performance at various bending angles of 0–90°, indicating a promising prospect for the PAA/GO hydrogel electrolyte in flexible wearable fields.

Prussian blue analogue derived NiCoSe4 coupling with nitrogen-doped carbon nanofibers for pseudocapacitive electrodes

The design of pseudocapacitive materials by coupling transition metal compounds with a conductive carbon matrix is important for the high performance of supercapacitors. Herein, we construct the Prussian blue analogue derived nickel-cobalt selenides coupling with nitrogen-doped carbon nanofibers (NiCoSe4-NCNFs) by carbonization and selenization of polyacrylonitrile nanofibers. The effect of selenization and element N doping on the morphological structure and surface chemistry of NiCoSe4-NCNFs are evaluated. Due to the accelerated electrolyte ion diffusion, enlarged active surface area and the modified surface chemistry by the strong interaction at NiCoSe4/NCNFs interfaces, NiCoSe4-NCNFs show excellent capacitive behaviors in 1 mol/L KOH, and the specific capacitance is 1257 F/g at 1 A/g with a rate capability of 78% and cyclic stability of 82.9%. The Gibbs free energy of adsorption OH− is calculated by density functional theory to investigate the charge storage mechanism. This work offers a new strategy to construct the transition metal selenides/carbon nanofibers hybrids for high-performance supercapacitor devices.

Facile synthesis of mesoporous MnCo2O4@MoS2 nanocomposites for asymmetric supercapacitor application with excellent prolonged cycling stability

A synergistic effect occurs in material science when a composite material's physical and chemical properties increase significantly as compared to its individual components. In the present work, MnCo2O4 (MCO) and MnCo2O4@MoS2 (MCOS) nanocomposites have been synthesized using the co-precipitation synthesis process. The main focus of the present research is to observe the impact of MoS2 on the electrochemical characteristics of the nanocomposites while keeping the MCO precursor quantity constant. The MCOS nanocomposite was synthesized with a homogeneous dispersion of 20 % MoS2 (MCOS20). It has the most significant enhancement in electrochemical properties due to its larger specific surface area (44 m2g−1) and mesoporous distribution of pore size. The MCOS20 nanocomposite as a single electrode possesses larger specific capacitances of 512 F g−1 at 0.5 A g−1 and exhibits a good rate capability. Besides that, the electrode exhibits excellent cycling stability of 91.87 % along with the coulombic efficiency of 99.57 % up to 5000 consecutive cycles, even at a high current density of 8 A g−1. An asymmetric supercapacitor (ASC) device has been fabricated with the MCOS20 nanocomposite as a cathode and commercially purchased activated carbon as an anode electrode to examine the practical utility of synthesized composite material. The device displays the highest specific energy density and power density of 36 Wh kg−1 and 19 kW kg−1, respectively. The device shows excellent stability up to 20,000 cycles at 3.5 A g−1 with a coulombic efficiency of 98.85 % and capacitance retention of 94.28 % in 6 M KOH gel electrolyte. Furthermore, the two devices illuminate red, blue, and yellow LEDs. It lights up for more than 3 min a red LED. We believe that our proposed MCOS20 nanocomposite has potential for use as electrodes in the fabrication of high-performance supercapacitor devices, owing to its simple manufacturing method and good electrochemical performance.

Enhanced Faradaic Capacitance in High-Performance Asymmetric Supercapacitor Device by Nickel Sites Encapsulated in Multilayered Nanotube

Enhanced Faradaic Capacitance in High-Performance Asymmetric Supercapacitor Device by Nickel Sites Encapsulated in Multilayered Nanotube

High-performance asymmetric supercapacitor device with nickel–cobalt bimetallic sites encapsulated in multilayered nanotubes

Assembled ASC and corresponding red LED lightning via connection of two ASCs in series.

Few-layered Ti3C2TXcoupled with Fe3O4nanoparticles assembled in a reduced graphene oxide hydrogel as advanced electrodes for high-energy supercapacitors

A high-performance symmetric supercapacitor device based on free-standing 3D porous Fe3O4@Ti3C2TX–rGO heterostructure hydrogel electrodes is built.

A high-performance asymmetric supercapacitor device based on CoO@CoAl-LDH hierarchical 3D nanobouquet arrays

3D core–shell CoO@CoAl-LDH nanobouquet arrays on Ni foam are promising active electrode materials for pseudocapacitors.

Recent advancements in zero- to three-dimensional carbon networks with a two-dimensional electrode material for high-performance supercapacitors.

Supercapacitors have gained significant attention owing to their exceptional performance in terms of energy density and power density, making them suitable for various applications, such as mobile devices, electric vehicles, and renewable energy storage systems. This review focuses on recent advancements in the utilization of 0-dimensional to 3-dimensional carbon network materials as electrode materials for high-performance supercapacitor devices. This study aims to provide a comprehensive evaluation of the potential of carbon-based materials in enhancing the electrochemical performance of supercapacitors. The combination of these materials with other cutting-edge materials, such as Transition Metal Dichalcogenides (TMDs), MXenes, Layered Double Hydroxides (LDHs), graphitic carbon nitride (g-C3N4), Metal-Organic Frameworks (MOFs), Black Phosphorus (BP), and perovskite nanoarchitectures, has been extensively studied to achieve a wide operating potential window. The combination of these materials synchronizes their different charge-storage mechanisms to attain practical and realistic applications. The findings of this review indicate that hybrid composite electrodes with 3D structures exhibit the best potential in terms of overall electrochemical performance. However, this field faces several challenges and promising research directions. This study aimed to highlight these challenges and provide insights into the potential of carbon-based materials in supercapacitor applications.

Polyaniline-tungsten oxide nanocomposite co-electrodeposited onto anodized graphene oxide nanosheets/graphite electrode for high performance supercapacitor device

Polyaniline-tungsten oxide nanocomposite co-electrodeposited onto anodized graphene oxide nanosheets/graphite electrode for high performance supercapacitor device

Transparent, photosensitive and highly efficient pseudocapacitive binder-free Mo-modified NiO thin film electrode for bifunctional optoelectronic and energy storage applications

We report a novel highly sensitive and pseudocapacitive transparent nickel oxide (NiO) thin film based electrode material fabricated on a conductive glass substrate using a facile binderless electrodeposition process. Effect of the incorporation of Mo-dopant ion on some surface structural and electrochemical properties of the electrode was examined for high performance optoelectronic and charge storage potentials. The material showed some uniqueness in some microstructural features and enhanced degree of crystallinity, suitable for charge extraction and transport with Mo doping. The deposited NiO film demonstrated red shift in band structure by exhibiting optical band gap narrowing from 3.88 to 3.61 eV with increasing Mo content. The degree of disorder as revealed from Urbach response of NiO film was found varying with Mo-content. The material also exhibited enhanced Ni2+ electronic transition states with increasing Mo content which quenched at a critical dopant concentration of 2.4 %. The fabricated NiO thin film electrode showed increased supercapacitive specific capacitance and areal capacity up to a peak value of 1412 Fg−1 and 101 mAh m−2 for 3 % Mo dopant content at 5 mVs−1 scan rate and 0.5 mA cm−2, respectively, but returned diminished at higher dopant content. Excellent cycling stability at ∼ 85 % after 5000 cycles, was also exhibited. Impedance spectroscopic features of Mo-doped NiO electrode indicated fast electrolytic ion transfer response with high rate charge storage capability. The study presents successful fabrication of Mo-modified NiO nanostructured electrode film and demonstrated the influence of Mo impurity on tailoring the properties of NiO host film as suitable electrode in high performance photocatalytic and supercapacitor devices.

Coupling W18 O49 /Ti3 C2 Tx MXene Pseudocapacitive Electrodes with Redox Electrolytes to Construct High-Performance Asymmetric Supercapacitors.

A pseudocapacitive electrode with a large surface area is critical for the construction of a high-performance supercapacitor. A 3D and interconnected network composed of W18 O49 nanoflowers and Ti3 C2 Tx MXene nanosheets is thus synthesized using an electrostatic attraction strategy. This composite effectively prevents the restacking of Ti3 C2 Tx MXene nanosheets and meanwhile sufficiently exposes electrochemically active sites of W18 O49 nanoflowers. Namely, this self-assembled composite owns abundant oxygen vacancies from W18 O49 nanoflowers and enough active sites from Ti3 C2 Tx MXene nanosheets. As a pseudocapacitive electrode, it shows a big specific capacitance, superior rate capability and good cycle stability. A quasi-solid-state asymmetric supercapacitor (ASC) is then fabricated using this pseudocapacitive anode and the cathode of activated carbon coupled with a redox electrolyte of FeBr3 . This ASC displays a cell voltage of 1.8V, a capacitance of 101 F g-1 at a current density of 1 A g-1 , a maximum energy density of 45.4Wh kg-1 at a power density of 900W kg-1 , and a maximum power density of 18000W kg-1 at an energy density of 10.8Wh kg-1 . The proposed strategies are promising to synthesize different pseudocapacitive electrodes as well as to fabricate high-performance supercapacitor devices.

The Synthesis of 2,6-Pyridinedicarboxylic Acid Modified Porous Polypyrrole Electrodes and Its Energy Storage Application

The well-designed porous polypyrrole/dicarboxylic acid (PPy/DCA) (0.02) electrodes were successfully synthesized by hydrothermal method. In this study, the interesting structural properties of the synthesized electrodes were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TG-DTA), Brunauer–Emmett–Teller (BET) and scanning electron microscopy (SEM). The scanning electron microscopy results showed that a large number of random pores were formed on the electrode surface during the polymerization of pyrrole. The galvanostatic charge-discharge measurements exhibited a specific capacity of 854.2 F.g−1 at 2.7 A.g−1 with an energy density of 884.4 Wh.kg−1. Further, the supercapacitor electrode showed a good cycling test (87.3%) after 4000 cycles at a current density of 10.0 A.g−1 and wide operating voltage (3.0 V). Our studies suggest that 2,6-pyridinedicarboxylic acid doped-polypyrrole electrodes with interesting structure and easy synthesized method are promising candidates for high-performance supercapacitor devices.