Key Takeaways & Executive Findings
- •• A simple polymerization reaction between p-benzaldehyde and 2,6-diaminopyridine yields interconnected carbon spheres with high N/O doping. • Optimizing the PMEC:KOH mass ratio (1:1) produces a microporous carbon with a high surface area of 2599.76 m2 g−1 and superior specific capacitance of 303.2 F g−1 at 0.5 A g−1. • The assembled symmetric supercapacitor delivers a high energy density of 11.3 Wh kg−1 at a power density of 250 W kg−1 in KOH electrolyte. • The strategy highlights the potential of N/O co-doped microporous carbon for high-performance aqueous supercapacitors.
Abstract
Carbon materials with adjustable porosity, controllable heteroatom doping and low-cost have been received considerable attention as supercapacitor electrodes. However, using carbon materials with abundant micropores, a high surface area and a high-dopant content for an aqueous supercapacitor with a high energy output still remains a challenge. We report the easy synthesis of interconnected carbon spheres by a polymerization reaction between p-benzaldehyde and 2,6-diaminopyridine. The synthesis involves adjusting the mass ratio of the copolymer and KOH activator to achieve increased charge storage ability and high energy output, which are attributed to the high ion-accessible area provided by the large number of micropores, high N/O contents and rapid ion diffusion channels in the porous structure. At a PMEC∶KOH mass ratio of 1∶1, the high electrolyte ion-adsorption area (2599.76 m2 g−1) and the N/O dopant atoms of the conductive framework of a typical carbon electrode produce a superior specific capacity (303.2 F g−[email protected] A g−1) giving an assembled symmetric capacitor a high energy delivery of 11.3 Wh kg−1@250 W kg−1. This study presents a simple strategy for synthesizing microporous carbon and highlights its potential use in KOH-based supercapacitors.
1. Introduction
Supercapacitors with high safety, rapid charge/discharge speed, long-term stability and high power output are considered to be the most promising energy storage devices. This is because they can store and release electrical energy based on the electrostatic interactions between ions in the electrolyte and electrodes[1–4]. However, supercapacitors usually suffer from relatively low energy output (～10 Wh kg−1) and they are unable to cope with commercial requirement of electrical applicances, such as portable devices, electric equipment/vehicles and so on[5–6].
Among the numerous electrode materials, porous carbon materials that integrate various interaction active sites and hierarchical porous architecture have been attracted considerable research attention in electrochemical energy storage[7–8]. The hierarchical porous structures of carbon materials with multiscale macro-, meso- and micropores synergistically furnish high-speed pathways for ion diffusion and enhanced ion-accessible area for charge accumulation[9–11]. Furthermore, the introduction of electron-donating dopants into the carbon skeleton has proven to be an efficient strategy for ameliorating the capability by enhancing electrical conductivity and the ion-accessible area, thereby generating additional pseudocapacitance[12–14]. Nevertheless, considerable challenges remain in optimising the synthetic strategies and enhancing electrochemical capability of hierarchical porous carbon with doped heteroatoms by rationally regulating of the element components and porous structure.
Porous carbon materials, such as activated carbon, carbon nanotube, and carbon sphere, are commonly used as electrodes for supercapacitors owing to their chemical stability, high conductivity and excellent cycle life[15–17]. A high specific ion-accessible area for porous carbon is a decisive factor for outstanding capability[18–19]. A hierarchical porous structure, low resistance and short diffusion paths for ion transport are necessary for electronic double-layer capacitors (EDLCs)[20–21]. Carbon electrodes with a pore diameter of < 0.7 nm are beneficial for maximising specific capacitance[22–23]. Pores with diameters of < 2 nm are suitable for selecting the electrolyte ion shape and size. A high ion-accessible surface area and ...
Loading authentic research manuscript (Pages 1–5)...
YAN Jing-jing, FANG Xiao-hao, YAO De-zhou, ZHU Cheng-wei, SHI Jian-jun, QIAN Shan-shan (2025). N/O co-doped microporous carbon as a high-performance electrode for supercapacitors. SinoTechIntel Verified Research. https://doi.org/10.1016/S1872-5805(NCM2025-40-01-13)
Research & Educational Purpose Only:The translations, structured abstracts, analytical annotations, and data reports provided by SinoTechIntel are intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoTechIntel claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the main achievement of this research?
The research demonstrates a simple synthesis of N/O co-doped microporous carbon spheres with a high surface area (2599.76 m2 g−1) and excellent specific capacitance (303.2 F g−1 at 0.5 A g−1), leading to a symmetric supercapacitor with high energy density (11.3 Wh kg−1 at 250 W kg−1).
How are the N/O co-doped microporous carbon spheres synthesized?
The carbon spheres are synthesized via a polymerization reaction between p-benzaldehyde and 2,6-diaminopyridine, followed by carbonization and KOH activation. The mass ratio of the copolymer to KOH is optimized to achieve the desired porous structure and heteroatom doping.
What are the key factors contributing to the high performance of the carbon electrode?
The high performance is attributed to the large number of micropores providing a high ion-accessible area, high N/O doping contents enhancing pseudocapacitance, and rapid ion diffusion channels in the porous structure.
What is the significance of the PMEC:KOH mass ratio of 1:1?
At a PMEC:KOH mass ratio of 1:1, the resulting carbon exhibits the highest surface area and optimal pore structure, leading to superior electrochemical performance.
What potential applications does this material have?
The N/O co-doped microporous carbon shows great potential as an electrode material for KOH-based supercapacitors, offering high energy and power densities for energy storage applications.
Related Technical Papers & Translations
A Novel Approach for Enhanced Brain Tumor Segmentation Using Multimodal MRI and Deep Learning
Brain tumor segmentation from multimodal MRI is crucial for diagnosis and treatment planning. In this study, we propose a novel deep learning framework that integrates structural and functional imaging modalities to improve segmentation accuracy. Our method employs a multi-scale attention mechanism and a hybrid loss function to handle class imbalance and boundary ambiguity. Evaluated on the BraTS benchmark, our approach achieves state-of-the-art performance, with Dice scores of 0.91, 0.87, and 0.84 for whole tumor, core, and enhancing tumor, respectively. Furthermore, we demonstrate the generalizability of our model across different scanners and protocols. Our findings suggest that the proposed method can significantly aid clinical decision-making and surgical planning.
Investigation of coupled acoustic and electrical responses and early warning approaches during re-loading of damaged coal
Initial damage from engineering disturbances in deep coal mining degrades mechanical properties and heightens dynamic-hazard risks, challenging conventional monitoring. This study probes the coupled acoustic-electrical responses of initially damaged coal under reloading and develops a multi-parameter, multi-level dynamic integrated early-warning model. Using a true-triaxial Split Hopkinson Pressure Bar (SHPB) system, we prepared specimens with graded damage by varying static deviatoric stresses and dynamic impacts. Uniaxial compression reloading was conducted with synchronous acoustic emission (AE) and resistivity monitoring. Joint time-domain responses of force, acoustics, and electricity delineated distinct loading stages. Time-frequency features were extracted via Fourier and wavelet transforms; crack architecture was quantified by 3D AE localization and fractal-dimension analysis. Initial damage markedly reduced load-bearing capacity. Resistivity decreased sharply with increasing deviatoric stress, while cumulative AE counts increased strongly. The AE spectrum evolved from bimodal to broadband with low- and high-frequency enhancement. The resistivity spectrum showed progressive bandwidth broadening, energy amplification, and high-frequency advancement. The AE spatial fractal dimension rose significantly during compaction. An integrated warning system combining multiscale entropy fusion, Temporal Convolutional Network (TCN)-Transformer forecasting, recurrence-network analysis, and a Bayesian framework yielded a 28.4 s lead time, offering a theoretical basis and technical pathway for intelligent prevention of dynamic hazards.
Influence of aggregate particle size on fracture behavior and energy evolution of cemented rockfill in the post-peak stage
Cemented rockfill (CRF) combines structural support with sustainable reuse of coal-derived solid waste. This study integrates digital image correlation, acoustic emission monitoring, and finite–discrete element simulations to investigate mechanical behavior, fracture development, and energy evolution of CRF containing 54% aggregate content with three grain-size distributions (5–10, 10–20, and 20–30 mm). Results indicate finer aggregates raise compressive strength and elastic modulus, and increase post-peak softening and residual stiffness. Fracture patterns transition from dominantly unidirectional failure in coarse specimens to pronounced X-shaped conjugate shear in fine specimens, with cracks initiating at boundaries and propagating inward. The proportion of failed joints at comparable strains decreases markedly with finer gradation, reflecting a more homogeneous crack network that enhances post-peak load retention and produces frequent minor stress fluctuations. Energy analyses reveal a coarse > medium > fine ordering in cumulative dissipation; however, finer aggregates delay rapid kinetic and dissipative energy release, promoting slower energy redistribution and improved load resistance. These findings quantify how aggregate gradation controls deformational mechanisms, crack topology, and energy partitioning, and provide design guidance for optimizing aggregate size and cementitious composition to enhance ductility, energy absorption, and structural reliability of CRF in underground engineering.