Carbon-based Electrode Materials Research Articles

Immobilization of TthLPMO9G on Carbon Felt for Potential Electrochemical Applications.

This study explores the entrapment, immobilization, and direct electron transfer-type bioelectrocatalysis mediated by TthLPMO9G on carbon-based electrode materials, focusing on carbon felt (CF) due to its high conductivity, chemical stability, and large surface area. At first, entrapment of an LPMO from Thermohelomyces thermophila,TthLPMO9G was achieved using Nafion-coated carbon fibers. At the next step, CF electrodes were chemically oxidized to introduce carboxyl groups, quantified by conductometric titration, and used for covalent immobilization of the enzyme. The immobilization process for TthLPMO9G was optimized, and the catalytic activity was assessed based on cellulose oxidation. The success of the immobilization process was evaluated using three parameters: yield (%), efficiency (%), and %recovery (%). Electrochemical studies, including cyclic voltammetry (CV) and Fourier-transform alternating current voltammetry (FTacV), were performed to evaluate TthLPMO9G's electrochemical activity. Immobilized LPMO activity was detectable only through the more sensitive FTacV. Direct electron transfer (DET) from the electrode to the enzyme active site remains a challenge. This work provides insight into the limitations of the studied strategies in LPMO-based electrocatalysis, thus offering guidance for improving immobilization process and electrochemical integration in future applications targeting DET bioelectrocatalysis.

Synthesis of hollow hierarchical porous carbon spheres from lignin by soft template and hydrothermal method for supercapacitors.

Synthesis of hollow hierarchical porous carbon spheres from lignin by soft template and hydrothermal method for supercapacitors.

Mechanochemical process enhancing pore reconstruction for dense energy storage of carbon-based supercapacitors

Improving the volumetric energy density of carbon electrode materials for supercapacitors is of significance to reducing the size of energy storage devices, and eliminating the ineffective pores in porous carbon electrode materials is the key to achieving dense storage of ions. Herein, we reconstruct the pore structure of commonly activated carbon via a facile high-energy mechanochemical process, by which modified activated carbon exhibits a much-increased packing density with an ultra-low specific surface area of 33 m2 g-1 without sacrificing the gravimetric specific capacitances, thereby enabling high volumetric capacitances up to 602 F cm-3. Gas adsorption characterization and small angle X-ray scattering tests collectively reveal the regulatory mechanism of mechanochemical process on pore structure reconstruction that high-energy mechanochemical treatment significantly eliminates the excess meso-/macro-pore volume to configure a compressed carbon skeleton structure and simultaneously increases proportions of micropore volume in the total pore volume, ultimately resulting in a cross-linked dense pore network structure. Benefitting from the optimized pore network and oxygen atoms introduced by mechanochemistry, the assembled aqueous symmetric supercapacitor in KOH electrolyte delivers a maximum volumetric energy density of 11.32 Wh L-1 when the volumetric power density is 223 W L-1. This work systematically reveals the effects of mechanical force on the pore reconstruction of carbon materials, and provides a simple method for enhancing the volumetric performances of carbon-based porous electrode materials.

Carbon-based electrodes for photo-bio-electrocatalytic microbial fuel and electrolysis cells: advances and perspectives.

The growing demand for sustainable energy and effective wastewater treatment has propelled the advancement of bio-electrochemical systems (BESs), particularly microbial fuel cells (MFCs) and microbial electrolysis cells (MECs). These systems integrate bioelectricity generation with organic and inorganic pollutant degradation, offering a sustainable solution for environmental remediation. However, challenges such as high overpotential, reliance on noble metal electrodes, and inconsistent performance have necessitated innovative improvements. The incorporation of photocatalysis into BESs has led to the development of photo-bio-electrochemical systems (PBESs), including photo-microbial fuel cells (PMFCs) and photo-microbial electrolysis cells (PMECs), which leverage optical energy to enhance efficiency. Carbon-based electrode materials, owing to their high porosity, conductivity, and biocompatibility, have emerged as ideal candidates for improving PBES performance. Advanced carbon nanostructures, such as graphene, carbon nanotubes, and metal-graphitic carbon nitride composites, have demonstrated superior photocatalytic properties, promoting enhanced charge separation, CO2 reduction, hydrogen production, and wastewater treatment. PBES integrating light-activated semiconductor materials with BESs, further amplify pollutant degradation and energy conversion efficiency. Despite significant progress, optimizing electrode materials and improving charge transport remain key challenges for scalable and cost-effective deployment. This review highlights the latest advancements in carbon-based electrodes for PBESs, detailing their mechanisms, photocatalytic properties, and future prospects in sustainable energy production and environmental remediation. By addressing existing material limitations and exploring novel photocatalytic enhancements, this work aims to contribute to the development of next-generation PBESs, fostering circular economy practices and carbon-neutral energy solutions.

Hydrothermal Pre-Carbonization Triggers Structural Reforming Enabling Pore-Tunable Hierarchical Porous Carbon for High-Performance Supercapacitors

The engineering of pore structures has great significance in the development of high-performance carbon-based supercapacitor electrode materials. Herein, we have successfully transformed jujube pits into hierarchical porous carbon (HJPC-4) with excellent capacitive properties via a unique hydrothermal–carbonization–activation strategy. Hydrothermal pretreatment is essential to regulate the supermesoporous and macroporous structure of samples and their superior electrochemical performances. Owing to the large ion-accessible, remarkable supermesoporous and macroporous pore volume, HJPC-4 exhibited ultra-high specific capacitance (6 M KOH: 316 F g−1 at 1 A g−1; EMIMBF4: 204 F g−1 at 1 A g−1), excellent rate performance (6 M KOH: 231 F g−1 at 100 A g−1; EMIMBF4: 154 F g−1 at 30 A g−1), outstanding cycling stability (6 M KOH: the retention rate is 92.11% after 60,000 cycles at 10 A g−1; EMIMBF4: the retention rate is 80% after 10,000 cycles at 5 A g−1), and ultimate energy/power density up to 91.09 Wh kg−1/24.25 kW kg−1 in EMIMBF4 two-electrode systems. This work presents unique insights into the effect of the pore structure of carbon-based materials on their capacitive energy storage.

Blue Energy Extraction Performance by Polyelectrolyte-Coated Porous Electrodes: Effects of Opposing Polyelectrolyte Interaction in Micropores.

In the capacitive mixing technique, the electrode used to extract blue energy is typically composed of a carbon-based porous electrode material. Polyelectrolyte (PE) surface coating on porous electrodes serves as an intermediate soft layer, which can significantly enhance the energy extraction performance (EEP). Herein, the blue energy extraction performance by using PE-coated electrodes is studied by a statistical thermodynamic theory, with the exploration of the interplay effects between opposing polyelectrolyte interactions and pore size. Because of the interaction between opposing PE coatings, the response of electrostatic properties in the pore to surface potential variations is enhanced during charging/discharging processes, leading to a better EEP. Both the surface charge accumulation and surface potential rise in the charging process can be raised as the results of PE coating. For the cases studied, the extraction efficiency can be promoted up to 45% compared with the cases of bare electrodes. For narrow pores, the PE promotion effects are suppressed by strong pore confinement. The optimal PE coating condition is determined by the competitive results between pore size (H) and polyelectrolyte chain length (N), with that Ĥ ≡ H/(2Nσ) being mostly in [0.1, 0.5], where σ is the PE segment diameter.

A multichambered carbon based electrode materials to realize efficient sodium-ion batteries

A multichambered carbon based electrode materials to realize efficient sodium-ion batteries

Tailoring Porous N-Doped Carbon Nanospheres for 3D Bottom-Up Electrode Design: A Versatile Synthesis Toolbox for Particle Size Independent Pore Size Control.

The rational design of carbon-based electrode materials plays an important role in improving the electrochemical properties of both, energy storage and energy conversion electrodes and devices. For most applications, well-defined and easily processable porous carbon-based electrode materials with controlled particle morphology (ideally spherical), particle size, and intraparticle pore size are desired. Here, a hard-templating synthesis toolbox is reported for highly-monodisperse meso- and macroporous N-doped carbon nanospheres (MPNCs) as a versatile material platform for the 3D bottom-up design of porous electrodes. With this approach, it is possible to change the MPNC pore size without affecting the particle size. By changing the template size, the pore size is adjusted between 15 and 99nm while maintaining a particle size ≈300nm. MPNCs are further used in electrochemical double-layer capacitors (EDLCs) as model application to demonstrate pore size effects on the performance independently from particle size effects, resulting in increasing specific capacitances for decreasing pores sizes, which correlates well with the surface area of the MPNCs and mass transport phenomena in the electrode. In conclusion, the toolbox allows to control intraparticulate porosities while keeping interparticulate properties constant, essential parameters to enable a true bottom-up 3D electrode design.

Tailored 3D Porous N-Doped Carbon Nanospheres for Bottom-up Electrode Design - Independent Pore and Particle Size Control for the Use in Model Electrodes

Design of porous carbon-based electrode materials and derived porous electrode structures is crucial for the performance of electrochemical energy storage and conversion devices. In that context carbon-based electrode material building blocks with well-defined properties are desired. Such properties include controlled morphology (preferably spherical), particle size, and intra-particle porosity along with controlled composition, surface chemistry, and processability. These factors influence the particle arrangement and electrode structure during processing, as well as electrolyte interaction, distribution, and mass transport phenomena within the electrode.In this work, we introduce a hard-templating method for producing highly uniform meso- and macroporous N-doped carbon nanospheres with independently tuneable pore and particle sizes, serving as a versatile material platform for the bottom-up design of 3D porous carbon electrodes. We could thereby customize the pore sizes between approximately 10 to 100 nm at a constant particle size, while particle sizes between 50 and 300 nm could be achieved for a constant pore size. Other physicochemical parameters such as chemical composition, graphitization, and surface functionalization remained constant across all samples, allowing for the exclusive investigation of pore and particle size effects independently from each other.We further used our different N-doped carbon nanospheres as building blocks for 3D porous electrodes and studied these in electrochemical double-layer capacitors with the aim to (i) showcase the versatility of our materials and (ii) examine pore and particle size effects on the performance. Indeed, electrochemical double-layer capacitors serve as an excellent model system for such investigations due to their sensitivity to carbon particle surface area, pore size, and mass transport phenomena within the 3D percolated structure of porous carbon electrodes.

Recent Advances in High-Performance Carbon-Based Electrodes for Zinc-Ion Hybrid Capacitors

Aqueous zinc-ion hybrid capacitors (ZIHCs) have emerged as a promising technology, showing superior energy and power densities, as well as enhanced safety, inexpensive and eco-friendly features. Although ZIHCs possess the advantages of both batteries and supercapacitors, their energy density is still unsatisfactory. Therefore, it is extremely crucial to develop reasonably matched electrode materials. Based on this challenge, a surge of studies has been conducted on the modification of carbon-based electrode materials. Herein, we first summarize the progress of the related research and elucidate the energy storage mechanism associated with carbon-based electrodes for ZIHCs. Then, we investigate the influence of the synthesis routes and modification strategies of the electrode materials on electrochemical stability. Finally, we summarize the current research challenges facing ZIHCs and predict potential future research pathways. In addition, we suggest key scientific questions to focus on and potential directions for further exploration.

The Impact of Supersaturated Electrode on Heterogeneous Lithium Nucleation and Growth Dynamics.

The concept of a lithiophilic electrode proves inadequate in describing carbon-based electrode materials due to their substantial mismatch in surface energy with lithium metal. However, their notable capacity for lithium chemisorption can increase active lithium concentration required for nucleation and growth, thereby enhancing the electrochemical performance of lithium metal anodes (LMAs). In this study, we elucidate the effects of the supersaturated electrode which has high active lithium capacity around equilibrium lithium potential on LMAs through an in-depth electrochemical comparison using two distinct carbon electrode platforms with differing carbon structures but similar two-dimensional morphologies. In the supersaturated electrode, both the dynamics and thermodynamic states involved in lithium nucleation and growth mechanisms are significantly improved, particularly under continuous current supply conditions. Furthermore, the chemical structures of the solid-electrolyte-interface layers (SEIs) are greatly influenced by the elevated surface lithium concentration environment, resulting in the formation of more conductive lithium-rich SEI layers. The improved dynamics and thermodynamics of surface lithium, coupled with the formation of enhanced SEI layers, contribute to higher power capabilities, enhanced Coulombic efficiencies, and improved cycling performances of LMAs. These results provide new insight into understanding the enhancements in heterogeneous lithium nucleation and growth kinetics on the supersaturated electrode.

Application of Carbon-Based Composites in Supercapacitors

Supercapacitors (SCs) are now one of the devices most likely to contribute to major developments in energy storage technology due to their ultra-high power density and rapidly increasing energy density. The electrode material for supercapacitors is usually carbon, due to its advantages of cheapness, good electrical conductivity, developed pore size, and ease access, especially the use of waste generated in the agricultural production process as raw material to make it renewable characteristics.However, the lower energy density of supercapacitors made of carbon materials compared to batteries limits the possibility of their wider application. In recent years, it has become an important research direction in the field of supercapacitors to substantially increase the energy density of supercapacitors by compositing carbon-based materials to provide both double layer capacitance and pseudocapacitance. This paper summarizes the latest key achievements and progress of carbon-based composites for supercapacitors at home and abroad in recent years, including the technical methods and properties of composites of biomass carbon materials with transition metal oxides, conductive polymers, metal-organic framework compounds, polymetallic oxides, and reduced graphene oxide, etc., reviews the strengths and weaknesses of various types of carbon-based composite electrode materials, and finally the future direction of the development of carbon-based composite electrode materials is prospected.

Fabrication of Coconut Shell-Derived Graphitic Activated Carbon for Carbon-based Electrode Materials

This study aims to convert low-value plantation biomass waste into high-value materials. The process involves transforming coconut shell charcoal (CSC) into activated carbon and subsequently producing coconut shell graphitic-like activated carbon (CSGAC). Using a thermal graphitization method with a FeCl3 catalyst at 900°C for 1 hour in a nitrogen atmosphere, graphite microstructures (CSGAC) were formed on the coconut shell activated carbon (CSAC) framework. XRD, FTIR, SEM, and BET analyses confirmed the successful formation of CSGAC. The electrical conductivity of CSGAC, measured at 148 µS, highlights its potential as a cost-effective, renewable, and environmentally friendly raw material for carbon-based electrodes.

Understanding intra-pore electrolyte resistances and distributed capacitances in carbon electrodes used in supercapacitors using a robust modeling process to separate the charge-storage occurring into macro-, meso-, and micro-pore structures

Understanding intra-pore electrolyte resistances and distributed capacitances in carbon electrodes used in supercapacitors using a robust modeling process to separate the charge-storage occurring into macro-, meso-, and micro-pore structures

Hierarchical porous self-supporting graphite carbon electrodes based on the biomimetic structure for supercapacitors

Hierarchical porous self-supporting graphite carbon electrodes based on the biomimetic structure for supercapacitors

Mesoporous carbon particles by biomass waste based on sulfonation and copper oxide functionalization as efficient and stable electrode material for supercapacitor.

Here, the hierarchical mesoporous-activated carbon particles obtained by KOH activation from pistachio shell wastes are modified by both the sulfonation process and CuO doping by hydrothermal heating (CuO@S-doped PSAC) for use as a supercapacitor. It is predicted that the electrochemical performance of the porous carbon electrode material obtained by such CuO doping and sulfonation process will be significantly increased with increased Faradaic capacitance. The electrochemical performance of CuO@S doped PSAC composite is systematically investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge/discharge (GCD) in the presence of 1M H2SO4, 1M Na2SO4, and 1M NaOH as electrolytes. The CuO@S doped PSAC-based electrode shows excellent stability with high specific capacitance up to 397.16 F/g at 0.1 A/g and 92.64% retention. Furthermore, FTIR, SEM, XRD, EDS, and nitrogen adsorption/desorption analyses are used for the characterisation of the obtained composites. Based on a significant supercapacitor performance, the synthesis strategy of carbon-based electrode material containing sulfonation and CuO modifications derived from agricultural biomass waste material is predicted to be a valuable example.

A Nanofibrous Polypyrrole Membrane with an Ultrahigh Areal Specific Capacitance and Improved Energy and Power Densities.

For conductive polymers to be competitive with carbon-based electrode materials, it is critical to increase their surface area and electroactivity. In this work, a thick nanofibrous polypyrrole (PPy) membrane with communicating interfiber spaces was prepared through one-pot interfacial polymerization for the first time. The electrochemical properties and conductivity of the membrane were studied with cyclic voltammetry, electrochemical impedance spectroscopy, and a four-point probe. Its morphology, chemistry, and thermostability were evaluated by scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The areal specific capacitances measured between 0.0 and 0.8 V at 1 mA/cm2 were 19179, 13264, 7238, and 4458 mF/cm2 for the membranes doped with docusate sodium (AOT), camphor-10-sulfonic acid (β) (CSA), Cl-, and poly(sodium 4-styrenesulfonate) (PSS), respectively. The capacity retentions after 1000 cycles were 83, 74, 67, and 61% for the AOT-, CSA-, PSS-, and Cl--doped membranes, respectively. The Coulombic efficiency was above 99% for all of the membranes. They showed energy densities of 1.7, 1.2, 0.7, and 0.4 mWh/cm2 and power densities of 0.61, 0.75, 0.66, and 0.62 mW/cm2 for the AOT-, CSA-, Cl--, and PSS-doped membranes, respectively. The ultrahigh areal specific capacitance of PPy-AOT is due to its nanofibrous structure. A mechanism has been proposed to explain how this structure is formed based on the role of AOT as the surfactant. This nanofibrous PPy membrane is easy to prepare and metal-free and offers a very high areal specific capacitance, making it an excellent candidate to construct electrodes in pseudosupercapacitors.

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

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

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

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

Carbon-based electrode materials for sensor application: a review

Carbon-based electrode materials for sensor application: a review