Carbon-based Electrode Materials Research Articles

Template-induced synthesis of MnO2-g-C3N4/C three-phase composites and its performance for supercapacitors

Carbon based electrode materials have many advantages such as large specific surface area, good electrical conductivity, easy obtained, safety and non-toxicity. In this work, we have induced the synthesis of MnO2-g-C3N4/C composites using the apricot mushroom as a biological template. The rod-shaped MnO2 is uniformly anchored on the surface of g-C3N4/C. Structural design of MnO2-g-C3N4/C composites improves the poor electrical conductivity of single MnO2. The results show that biocarbon has good stability and conductivity, g-C3N4 provides more reactive sites, and MnO2 substantially enhances the pseudocapacitance of the material, thus realize the synergistic effect for higher supercapacitor property. Based on its excellent three-phase interface structure, the MnO2-g-C3N4/C’ capacitance was able to reach 276F·g−1 with a capacitance retention of 96 % after 1000 cycles. Therefore, this material has potential application in the energy storage industry.

Boron-manganese-nitrogen co-doped three-dimensional porous carbon realizes superior capacitive lithium-ion storage

Three-dimensional (3D) porous carbon has sufficient specific surface area and anchor positioning points. The pore structure facilitates uniform charge distribution, and buffers volume changes during stripping. However, single carbon materials have limited theoretical capacity and short cycle life. Here, 3D porous carbon material BCN/Mn-6 (B,N and Mn co-doped porous carbon with 6 mmol Mn content) co-doped with manganese, boron and nitrogen was synthesized by heat treatment. Affective modulation of the material structure and surface functional groups was achieved by adjusting the amount of manganese doping. The metal element doping can promote the diffusion of lithium ions, and the formed vacancies and defects can be used as lithium storage sites. Nitrogen doping can improve the dispersion and stability of metals and oxides, and regulate the redox capacity. Co-doping of metals and heteroatoms synergistically improves electrical conductivity. Thus, BCN/Mn-6 exhibits excellent cycling stability (99.60 % Coulombic efficiency after 300 cycles) and specific capacity (779.9 mAh/g), and shows capacity rise. This study provides a new direction for the preparation of carbon-based electrode materials doped with heteroatoms and the study of capacitive energy storage mechanisms.

Carbon-based electrode materials for sensor application: a review

Carbon-based electrode materials for sensor application: a review

Binder-free all-carbon composite supercapacitors

Carbon-based electrode materials have widely been used in supercapacitors. Unfortunately, the fabrication of the supercapacitors includes a polymeric binding material that leads to an undesirable addition of weight along with an increased charge transfer resistance. Herein, binder-free and lightweight electrodes were fabricated using powder processing of carbon nanofibers (CNFs) and graphene nanoplatelets (GNPs) resulting in a hybrid all-carbon composite material. The structural, morphological, and electrochemical properties of the composite electrodes were studied at different concentrations of GNPs. The specific capacitance (Cs) of the CNFs/GNPs composite was improved by increasing the concentration of GNPs. A maximum Cs of around 120 F g−1 was achieved at 90 wt% GNPs which is around 5-fold higher in value than the pristine CNFs in 1 M potassium hydroxides (KOH), which then further increased to 189 F g−1 in 6 M KOH electrolyte. The energy density of around 20 Wh kg−1 with the corresponding power density of 340 W kg−1 was achieved in the supercapacitor containing 90 wt% GNPs. The enhanced electrochemical performance of the composite is related to the presence of a synergistic effect and the CNFs establishing conductive/percolating networks. Such binder-free all-carbon electrodes can be a potential candidate for next-generation energy applications.

Effects of Intrinsic Defects in Pt-Based Carbon Supports on Alkaline Hydrogen Evolution Reaction.

Carbon material has widely been utilized in the synthesis of efficient carbon-supported Pt (Pt/C) catalysts, in which the structural properties greatly influence the electrocatalytic performances of Pt/C catalysts. However, the effects of intrinsic defects in carbon supports on the performance of the alkaline hydrogen evolution reaction (HER) have not been systematically investigated. Herein, porous carbon supports with different degrees of intrinsic defects were prepared by a simple template-assisted strategy, and the resulting samples were systematically studied by various analytical methods. The results suggested that the presence of abundant intrinsic defects (vacancy and topological defects) in the carbon support was advantageous in terms of favoring the dispersion and anchoring of Pt species, promoting electron transfer between Pt atoms and the carbon support, and tuning the electronic states of Pt species. These features improved the HER performance of Pt/C catalysts. Compared to the nontemplate-assisted carbon-supported Pt catalyst (Pt/NTC) with an overpotential of 178 mV, the optimized template-assisted carbon-supported Pt catalyst (Pt/TC) exhibited a lower overpotential of 58 mV at 10 mA cm-2. Besides, the Pt/TC catalyst displayed better HER durability than the Pt/NTC catalyst owing to its strong metal-support interaction. The DFT calculations confirmed the important role played by intrinsic defects (vacancy and topological defects) in stabilizing Pt atoms, with Pt-C3 coordination identified as the most favorable structure for improving the HER performance of Pt. Overall, novel insights on the significant contribution of intrinsic defects in porous carbon supports on the HER performances of Pt/C catalysts were provided, useful for future design and fabrication of advanced carbon-supported catalysts or other carbon-based electrode materials.

Research progress on lignin-based carbon electrode materials in rechargeable batteries

Lignin, with its carbon content of up to 60%, can be an ideal precursor for the preparation of carbon materials. Carbonaceous materials obtained from lignin can be transformed into porous and structural morphologies at different scales, providing a biomass approach to energy conversion and storage in batteries. Focusing on lignin-derived carbon materials, this paper summarizes the different morphologies and structures of lignin-based carbon obtained through different preparation methods, and the different electrochemical properties exhibited by these materials as electrode materials for rechargeable batteries (lithium-ion batteries, sodium-ion batteries, lithium-sulphur batteries, etc.). In addition, the development prospects and challenges of lignin-based carbon materials in the field of rechargeable batteries are summarized, providing ideas for the next step in the design and development of high-performance lignin-based carbon-based electrode materials.

Spinning of Carbon Nanofiber/Ni–Cu–S Composite Nanofibers for Supercapacitor Negative Electrodes

The preparation of composite carbon nanomaterials is one of the methods for improving the electrochemical performance of carbon-based electrode materials for supercapacitors. However, traditional preparation methods are complicated and time-consuming, and the binder also leads to an increase in impedance and a decrease in specific capacitance. Therefore, in this work, we reduced Ni-Cu nanoparticles on the surface of nitrogen-doped carbon nanofibers (CNFs) by employing an electrostatic spinning method combined with pre-oxidation and annealing treatments. At the same time, Ni-Cu nanoparticles were vulcanized to Ni–Cu–S nanoparticles without destroying the structure of the CNFs. The area-specific capacitance of the CNFs/Ni–Cu–S–300 electrode reaches 1208 mF cm−2 at a current density of 1 mA cm−2, and the electrode has a good cycling stability with a capacitance retention rate of 76.5% after 5000 cycles. As a self-supporting electrode, this electrode can avoid the problem of the poor adhesion of electrode materials and the low utilization of active materials due to the inactivity of the binder and conductive agent in conventional collector electrodes, so it has excellent potential for application.

High-energy-density zinc ion capacitors based on 3D porous free-standing defect-reduced graphene oxide hydrogel cathodes.

Zinc ion capacitors (ZICs) have shown potential for breaking the energy density ceiling of traditional supercapacitors (SCs) via appropriate device design. Nevertheless, a significant challenge remains in advancing ZIC positive electrode materials with excellent conductivity, high specific capacitance, and reliable cycle stability. A highly attractive option for carbon-based electrode materials is reduced graphene oxide (RGO) due to its vast specific surface area, prominent porosity, and 3D cross-linked frame. However, the tight stacking of RGO sheets driven by van der Waals forces can restrict active sites, decrease specific capacitance, and elevate electrochemical impedance. To overcome these challenges, 3D defective RGO (DRGO) hydrogels were prepared by a metal Co cocatalytic gasification reaction. This method produced mesoporous defects on the surface of RGO hydrogels via a low-temperature hydrothermal self-assembly strategy. The surface of the layer has a wide and uniform distribution, which can offer abundant redox active sites, rich ion transfer channels, and fast reaction kinetics. In this work, 3D DRGO//Zn exhibited a wide operating window (0-1.8 V), high specific capacitance (189.39 F g-1 at 1 A g-1), outstanding energy density (85.23 W h kg-1 at 960.31 W kg-1; 52.36 W h kg-1 at 17454.87 W kg-1), and persistent cycling life (98.86% initial capacitance retention after 10 000 cycles at 10 A g-1). This study emphasizes the device design of ZIC and promising prospects of using 3D DRGO hydrogel as a feasible positive electrode for ZIC.

Bio-inspired carbon electrodes for metal-ion batteries.

Carbon has been widely used as an electrode material in commercial metal-ion batteries (MIBs) because of its desirable electrical, mechanical, and physical properties. Still, traditional carbon electrodes suffer from limited mechanical stability and electrochemical performance in MIBs. Drawing inspiration from biological species, the carbon allotropes, such as fullerenes, carbon nanotubes, and graphene, can be engineered into mechanically robust, highly conductive frameworks with enhanced ion storage and transport capabilities for MIBs. Here, we present an assortment of bio-inspired carbon electrodes that have enhanced the cycling stability, capacity retention, and overall performance of MIBs. In addition, mimicking the structure and functionality of biological systems has led to the development of flexible MIBs whose performance does not degrade even when stretched, bent, or twisted. Finite element analysis (FEA) is a useful guide in identifying such bio-inspired carbon frameworks because it can simulate and analyze potential failure scenarios, such as stress build-up or structural collapse in MIBs. This review highlights through several examples that there is much scope for improving carbon-based electrode materials through bio-inspired designs for practical high-performance MIBs.

Carbon-Based Electrode Materials for Electrocatalytic Transformations

Industrial processes for the synthesis of chemicals and fuels utilise selective hydrogenation reactions. The need for high temperatures and high pressure of H2 makes these reactions energy intensive and only viable on a large scale, requiring expensive transport of materials. Electrocatalytic hydrogenation (ECH) could potentially bypass these limitations, running at ambient conditions and generating the adsorbed hydrogen in-situ. The interest in new electrocatalyst materials increased in recent years, as ECH offers a synthetic route for fuels and value-added chemicals with a reduced carbon footprint. The development of new low-cost catalyst materials will be paramount for the integration of ECH into economic activities.In this work we focus on heteroatom-modified carbon based electrode materials for the ECH. Carbon materials possess a list of beneficial properties for electrochemical applications: they are widely available, environmentally benign, stable at cathodic potentials and can be tailored towards specific applications. One way of tailoring is to dope the carbon with heteroatoms like nitrogen.Nitrogen-doped carbon thin films have been synthesised using sputter deposition followed by an annealing process, to control graphitisation and nitrogen distribution of the carbon material. These model electrodes were investigated by themselves and as supports for thin nanoparticle films of MoS2 in the ECH and the hydrogen evolution reaction (HER), as the Volmer step of the HER is needed in the ECH. This allowed us to understand the influence of nitrogen moieties on reduction rates in the absence of morphological effects. The results suggest possible strategies for developing electrocatalysts for the ECH based on functional carbons.[1] Orella, M.J.; Román-Leshkov, Y.; Brushett, F.R., Emerging opportunities for electrochemical processing to enable sustainable chemical manufacturing. Current Opinion in Chemical Engineering 2018, 20, 159–167.[2] Behan, J. A.; Stamatin, S. N.; Hoque, M. K.; Ciapetti, G.; Zen, F.; Esteban-Tejeda, L.; Colavita, P. E., Combined Optoelectronic and Electrochemical Study of Nitrogenated Carbon Electrodes. The Journal of Physical Chemistry C 2017, 121 (12), 6596-6604.[3] Nolan, H.; Schröder, C.; Brunet-Cabré, M.; Pota, F.; McEvoy, N.; McKelvey, K.; Perova, T. S.; Colavita, P. E., MoS2/carbon heterostructured catalysts for the hydrogen evolution reaction: N-doping modulation of substrate effects in acid and alkaline electrolytes. Carbon 2023, 202, 70-80.

Fabrication of predesigned 3D carbon based microstructures via two-photon vat photopolymerization and susceptor-assisted microwave post-processing

This study presents a fabrication strategy for 3D carbon microstructures using via two-photon vat photopolymerization (2p-VPP) and susceptor-assisted microwave pyrolysis (SMWP). Fabricating carbon-based electrode materials with miniaturized functional structures is pivotal for developing high-performance electrochemical microdevices. However, efficiently producing these structures in the submicron regime with desired materials is still challenging. To address this, a hybrid microfabrication strategy was developed, and 3D carbon-based microstructures with submicron resolution were successfully produced. A carbon nanotube nanocomposite photoresist (SCNT-PR1) with improved dispersibility was first prepared. After a comprehensive printability assessment, 3D microstructures with a resolution of 833 ± 54 nm were produced using 2p-VPP. Through SMWP, the microstructures were transformed into pyrolytic carbon (PyC) nanocomposite microstructures with retained geometrical features. SMWP was shown to produce PyC with a less disordered carbon atomic structure, thanks to the accelerated pyrolysis reaction under MW irradiation, when compared to pyrolysis using a conventional furnace. The resistivity was reduced by over 75% from 0.69 ± 0.13 Ω cm to 0.16 ± 0.01 Ω cm, and enhanced electrochemical performance was confirmed. The fabricated PyC nanocomposite showed a further 12% reduction in electrical resistivity and a 20% lower charge transfer resistance for the redox reaction when using SCNT-PR1 as the precursor. Overall, this hybrid fabrication strategy demonstrates the advantages of producing 3D carbon microstructures with precise control over the geometric features and enhancing electrical and electrochemical properties compared to the conventional pyrolysis method. Its potential could be extended to the fabrication of miniaturized electrochemical devices, including microelectronics and point-of-care devices.

Rectorite in flow-electrode capacitive deionization with three-dimensional current collector to achieve cost-effective desalination

The innovative design of collector is a top priority to drive the advancement of flow electrode capacitive deionization (FCDI) technology. Currently, the majority of FCDI research has concentrated on the implementation and modification of carbon-based flow electrode materials, while ignoring the effect of the current collector in FCDI. In this study, a 3D-FCDI configuration with porous titanium foam as the collector is designed, and rectorite (Rec) is used as the flow electrode in 3D-FCDI. Thanks to the porous structure of the 3D current collector, the collision opportunities of electrons with the Rec particles are increased and the long-distance migration of electrons in the conventional graphite collector is overcome, thus improving the system conductivity. The Rec exhibits good electrode dispersion, desalination rate, and energy consumption at low cost. In addition, the ASAR of Rec can be achieved by adjusting the electrode concentration (5 wt%), electrode flow rate (25 mL min−1) and operating voltage (1.8 V) to 11.43 μg cm−2 min−1. This study demonstrates the capability of 3D-FCDI configuration to advance the creation and implementation of FCDI.

MWCNT/AC Electrode Synthesis on Supercapacitor Performance with NaCl Electrolyte

The increase in the use of electronics requires high enough energy storage so that the use of supercapacitors is very necessary. The solution is obtained by the presence of carbon-based electrode material (MWCNT / AC). Our research used MWCNT and AC because it has high conductivity using the doctor blade method and a three-electrode system. Electrochemical analysis was performed by adding electrolyte NaCl and tested with CV and EIS. Electrolyte concentration of 2 M NaCl which has a high value of 11.1559 F / g with an energy density of 1580.58 Wh / kg and a power density of 1138017 W / kg. The resistor, capacitor and CPE values in the EIS test are generated respectively R=3.1234 Ω, C=0.0004 F, and Z_CPE=0.0005 F⁄s.

Optimizing the application of high-performance supercapacitors: Utilizing 3D honeycomb mesoporous carbons derived from hybrid biomass

Biomass garbage convert into highly efficient porous carbon-based electrode materials for supercapacitors is of great significance to the current energy-friendly society. Herein, an efficient electrode material of three-dimensional honeycomb porous carbons is developed for supercapacitor by employing sunflower plate and rice husk as a precursor. Particularly, SiO2-rich rice husk plays a crucial role in the formation of porous structure and three-dimensional morphology. Benefiting from the high surface area and more defective carbon nano-framework, high contents of nitrogen and oxygen dopants, abundant porosity, the resultant optimal RSC-1-1 exhibits a specific capacitance of 448 F/g at 0.5 A/g in 6 M KOH. Furthermore, the capacitive performance of RSC-1-1 in acidic and neutral media are also analysed systematically. In addition, the energy densities of RSC-1-1 assembled supercapacitors 6 M KOH, 1 M Na2SO4 and PVA/KOH gels are 12.15 Wh/kg, 35.55 Wh/kg, and 29.06 Wh/kg, respectively. This study demonstrates the great potential of twin substance derived electrode materials in constructing high performance supercapacitor.

Modulating the surfaces functional groups and defects in carbon via salt template method for high-performance capacitor deionization

Conventional carbon-based materials have been widely applied for capacitive deionization (CDI) because of their excellent electrical conductivity and specific surface area. The surface functional group and defect of carbon materials have a critical impact on CDI performance. Hence, a hierarchical mesoporous/macropores carbon (MPC) with abundant quinone functional groups (C = O) and defects were synthesized by a salt template method. The introduction of C = O functional groups and defects not only effectively shortens the ions transport path, but also enhances the pseudocapacitive behavior of carbon materials. As a result, the MPC represents a fantastic desalting capacity of 31.3 mg g−1 for sodium salt (500 mg L–1 NaCl) at an applied voltage of 1.2 V. Meanwhile, the MPC also shows superior salt adsorption rate and great cycling performance. In addition, the desalination mechanism was analyzed in detail by systematic ex-situ measurements. Here, this work presents a novel perspective for designing high-performance carbon-based CDI electrode materials.

Mesoporous dopamine-modified leaf-like zeolitic imidazolate frameworks derived carbon for efficient capacitive deionization

The onstruction of novel porous carbon materials for efficient desalination is crucial but remains challenging for capacitive deionization (CDI) development. Herein, a micelle-assisted strategy was raised to coat mesoporous polydopamine (mPDA) on the surface of two-dimensional (2D) leaf-like zeolitic imidazolate frameworks (ZIFL) followed by confinement pyrolysis. The introduction of the mPDA layer can not only mitigate the backbone collapse of ZIFL during pyrolysis to build a favorable porous environment for efficient ion transport and diffusion, but also induce explosive growth of carbon nanotubes (CNTs) to improve the electron conductivity. As expected, the derivative ZIFL@mPDA-C possessed a high desalination capacity of 41.9 mg g−1 in 500 mg L-1 NaCl solution at an operating voltage of 1.2 V. In particular, the retention ratio of the desalination capacity of ZIFL@mPDA-C was about 100 % after 50 consecutive adsorption-desorption cycles, while its leaf-like morphology and hierarchical pore structures were well preserved. This study highlights the importance of rationally designed structures and components for the performance breakthrough of carbon-based CDI electrode materials.

Bidirectional pore-creating strategy towards lignin-based heteroatom-doped porous carbon for supercapacitors

Significant pursuits have been committed to manufacturing high-performance lignin carbon-based supercapacitor electrode materials due to their high carbon content, abundant raw resources, and environmentally-friendly. However, the pessimistic accessible porous structure and appetency to the electrolyte of electrode materials are two vital factors for restricting its performance. Here, a bidirectional pore-creating strategy is proposed to construct heteroatom-doped lignin-based porous carbon (HLPC) materials with a high electrochemical active area at supramolecular-level. In this process, activated-mediates with different pore-forming functions are assembled into lignin-based supramolecules by electrostatic forcing, and then hierarchical pore-creation and heteroatom doping are accomplished simultaneously in the pyrolysis process. The obtained carbon materials possess a tunable specific surface area of 543.4–1502.3 m2 g−1 and high heteroatom content of 9.4–16.2 at.%. Benefit from its admirable physicochemical properties, the HPLCs deliver a high ions appetency, ultrahigh capacitance of 380.5 F g−1 at 0.2 A g−1, and extremely long cyclic stability (100% after 10,000 cycles), which is superior 2.5-fold than that of YP-80F at the same mass loading. More promising, symmetrical electrode devices based on HLPCs possess a preeminent energy density of 30.0 Wh kg−1 in aqueous electrolyte. Overall, this protocol provides a new avenue for promoting the advancement of electrode materials in industrial-scale supercapacitors and manufacturing high-value-added products from plentiful bio-waste.

Facile synthesis of CuAl2O4/rGO nanocomposite via the hydrothermal method for supercapacitor applications

Transition metal-based spinel oxides are fascinating supercapacitor electrodes materials due to their good specific capacitance (Cs) and cost-effectiveness. But the spinel materials show poor cycling stability due to their limited surface area. This issue was reduced by using carbon-based electrode materials such as rGO, which enhances the electroactive surface area that leads to improve the number of reactive sites. In this research, a simple hydrothermal approach was utilised to synthesise the CuAl2O4/rGO (CAO/rGO) nanocomposite. It successively characterised with different analytical techniques to study the physiochemical property of the synthesized materials. Additionally, the potential of the materials as the electrode was determined with a three-electrode configuration by utilising different electrochemical tools that were performed to assess the characteristics of the electrode material. The synthesised nanocomposite exhibits a magnificent specific capacitance (Cs) of 1206.14 F/g at 1 A/g, while demonstrating specific energy (Ed) of 34.83 Wh kg−1 and specific power (Pd) of 228 W kg−1 which is higher than individuals and also shows high retention capacitance value of 93.36% after 8000th charge/discharge (GCD) cycles. The symmetric behaviour of the fabricated electrode is also determined with two electrode systems exhibiting the specific energy and specific capacitance of 16.54 Wh kg−1 and 601.91 F/g, correspondingly. This study demonstrates that incorporating rGO into CuAl2O4 nanoarray improves energy storage performance and it has the potential to work in other energy storage devices.

A review on effect of conducting polymers on carbon-based electrode materials for electrochemical supercapacitors

Supercapacitors, commonly referred to as electrochemical capacitors, are a significant type of energy storage devices with more energy density than capacitors, greater power density, and longer cycle life than batteries. Conventionally, the electrode material of supercapacitors is composed of metal oxides, inorganic complexes, carbon-based materials, and conducting polymers. Researchers have attempted numerous combinations of aforementioned materials to create electrode material with enhanced electrochemical properties. However, supercapacitor (SC) electrodes constructed with pure conducting polymers (CPs) have poor cycling stability, resulting in a rapid decrease in specific capacitance. To improve the electrochemical property of such materials, researchers have attempted to construct binary and ternary composites of various CPs by mixing them with carbonaceous materials and metal oxides. In this review, SC electrode materials prepared from CPs, such as polyaniline (PANI), polythiophene (PTh), polypyrrole (PPy) and their composites with carbonaceous materials such as activated carbon (AC), carbon nanotubes (CNTs), reduced graphene oxide (rGO), graphene and carbon quantum dots have been discussed.

A novel self-bonding 3D carbon particle bioanode derived from agricultural residue for improving the enrichment of electroactive bacteria in microbial fuel cell

Many researchers focus on regulating the structure and surface properties of electrode materials to improve their biocompatibility, promote the growth of electroactive bacteria and accelerate the efficiency of extracellular electron transfer, thus improving the performance of microbial fuel cells (MFCs). For the commonly used three-dimensional (3D) carbon-based electrode materials, it is important to explore the key factors that affect their performance as anode for the controllable customization of materials. In this study, a novel method suitable for common agricultural residue was developed to prepare self-bonding 3D spherical biochar particles with high mechanical strength after activation with sulfuric acid. The MFC with particles pyrolyzed at 900 °C as anode achieved the highest power density (2066.7 ± 7.0 mW m−2) and a higher abundance of electroactive bacteria (92.8%). Correlation analysis of environmental factors showed that the specific surface area, micropore area, total pore volume and capacitance of the material were positively correlated with the maximum power density, current density, biomass, accumulated charge of MFC and the abundance of Bacteroides, Geobacter, norank_PHOS-HE36 and Clostridium_sensu_stricto_10 on the bioanode. Desulfovibrio and Comamonas showed a higher affinity with oxygen-containing functional groups on materials. The conductivity and pore structure of 3D carbon materials were the dominant factors affecting MFC performance. The findings will provide guidance for the customized structure of 3D carbon electrode to improve the performance of MFCs.