Helical carbon coils (HCCs) demonstrate significant potential as microwave-absorbing materials (MAMs) due to their unique 3D helical structure, moderate conductivity, and excellent dispersibility. Currently, the majority of research focuses on single-scale HCCs. However, how the change of HCC diameter affects their microwave absorption (MA) properties has not been studied yet. In this work, HCCs with average coil diameters of approximately 0.5, 1, 2, and 6 mu m have been successfully synthesized via chemical vapor deposition method, achieving wide-range cross-scale coil diameter adjustment. It is found that the internal carbon structure transitions from polycrystalline amorphous to amorphous with the increase of coil diameter, leading to the increase of defect polarization but reduction of conductive loss. Especially, the induction-resistance behaviors of HCCs and the capacitive behavior of multiple interfaces jointly form R-C-L circuits, enabling the shift of absorption peaks to high frequency with the increase of diameter by the circuit tuning. Furthermore, the combination of HCCs with different diameters leverages their synergistic MA effects, significantly broadens the effective absorption bandwidth (EAB). The optimized multi-scaled HCCs achieve an EAB of 7.2 GHz, minimum reflection loss of -61.8 dB at filling ratio of only 6 wt%, offering a promising route toward lightweight, broadband, high-performance MAMs.

Traditional trial-and-error approaches hinder the development of efficient electromagnetic absorbers, due to insufficient understanding of dielectric dispersion optimization. Through a universal theoretical framework to determine the ideal permittivity range and achieve wideband absorption at small thicknesses within practical limits remains challenging. In this study, based on transmission line theory, we decoupled the real and imaginary parts of permittivity, derived analytical formulas for impedance matching (Z) and reflection loss (RL), and visually analyzed parameter effects on absorption performance. The results indicate that thickness of an absorber primarily shifts the peak positions of the RL and Z curves, whereas the imaginary part of permittivity mainly modulates the peak magnitude with minimal location shift, while the real part of permittivity considerably alters both magnitude and position. Subsequently, universal ranges of permittivity under different thickness conditions were summarized through inverse numerical analysis. Furthermore, machine learning was introduced to establish the relationship between permittivity and effective absorption bandwidth (EAB), leading to an optimized dielectric curve with an EAB of 10.5 GHz at 2 mm thickness. This study provides a generalizable methodology to determine dielectric properties across diverse conditions, extending beyond the presented data and offers a theoretical foundation for advancing thin-thickness broadband absorption technology.

The unique advantages of porous materials with spatial arrangement have inspired the development of advanced microwave absorption (MA) materials. It is a good strategy to design pore sizes and a customized spatial arrangement for optimizing electromagnetic synergistic behaviors. Herein, a micro-meso-macropores structure with in-plane multi-components has been successfully constructed in carbon foam (CF). The innovative design is that the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) film on CF not only serves as an in situ source of O and S anions for forming Co, CoO, and Co9S8 phases through ion-exchange and competitive reactions, but also effectively induces an in-plane arrangement of carbon nanocoils and metal-organic frameworks (MOFs). Experiments and simulations revealed a multi-level collaborative attenuation mechanism spanning from macroscopic conductive loss to nanoscale polarization. More importantly, the in-plane configuration of multi-components further amplifies electromagnetic coupling. The optimized structure achieved excellent broadband absorption performance across a wide range of incidence angles. Furthermore, after an additional periodic structural design, the effective absorption bandwidth was expanded from 8 to 12 GHz, and the minimum reflection loss value was improved from -20.5 to -60 dB. Analysis indicates that the ultra-broadband characteristics of the array microwave absorber originate from the synergistic regulation of electromagnetic cooperative effects and edge diffraction effects by the periodic structure.

In today's information technology-driven society, microwave absorbing and shielding materials play an increasingly important role in both military equipment and civilian electronic devices. Especially, lightweight and high-efficiency have become crucial metrics for the design of absorbing materials. In this study, we have synthesized a kind of lightweight hollow carbon bowl@polypyrrole (HCBP) composites using a combination of a room-temperature one-step reaction, template etching, high-temperature carbonization, and chemical oxidation. The unique bowl-like architecture, characterized by sharp edges and high curvature, significantly enhances both dipole and interfacial polarization losses. The coating of thin polypyrrole films on the surfaces of carbon bowls further reinforces these polarization losses while effectively modulating the surface electromagnetic characteristics of the composite. As a result, the HCBP composite demonstrates exceptional electromagnetic wave absorption performance, achieving a minimum reflection loss of -62.15 dB at 16.66 GHz with a thickness of 2.16 mm, along with an effective absorption bandwidth of 6.88 GHz at 2.49 mm thickness. This advancement opens new possibilities for the precise design of dielectric composite electromagnetic wave absorbers with both strong absorption and broad bandwidth characteristics.

Gradient porous carbon has become a potential electrode material for energy storage devices, including the aqueous zinc-ion hybrid capacitor (ZIHC). Compared with the sufficient studies on the fabrication of ZIHCs with high electrochemical performance, there is still lack of in-depth understanding of the underlying mechanisms of gradient porous structure for energy storage, especially the synergistic effect of ultramicropores (<1 nm) and micropores (1-2 nm). Here, we report a design principle for the gradient porous carbon structure used for ZIHC based on the data-mining machine learning (ML) method. It is clarified that the combination of 0.6-0.9 nm ultramicropore and 1.6 nm micropore achieves the highest specific capacity. Molecular dynamic simulation was further employed to investigate the electric double-layer structures in several kinds of electrified gradient porous carbon electrode/electrolyte interface. It is found that the Zn2+ ions in the 1.6 nm micropore balance the most charges of the electrode surface as the counterion with the modification of the solvation structure. Furthermore, the ML-based force field is trained and employed in the simulation of the ion charging dynamic in the gradient porous carbon electrode. Based on the free energy profile result, the remarkable benefit of the step-by-step desolvation process is found in the 0.86 and 1.6 nm gradient porous structure, which could be the origin of the enhanced ion charging dynamic and better capacity retention performance.

Carbon microcoils (CMCs) were successfully synthesized via catalytic anisotropy induced by multiple particles. In this study, Ni nanoparticles with an average diameter of similar to 50 nm were employed as catalysts, and sulfur vapor was introduced during chemical vapor deposition (CVD) to induce "welding" of the Ni nanoparticles, forming multi-particle aggregates. Using C2H2 as the carbon source, the significant heterogeneity in catalytic activity across different sites within the Ni aggregates led to catalytic anisotropy, driving the helical growth of CMCs. The change in particle size of Ni aggregates effectively regulates the coil diameter of CMC to the micrometer level. This work not only reveals a new multi-particle growth mechanism for CMCs but also provides a theoretical basis for their controllable synthesis, high-purity production, and large-scale applications.

Omnidirectional strain sensors have attracted considerable attention due to their potential in flexible electronics applications. However, most existing designs based on multi-unit integrated arrays require multiple electrodes and complex signal acquisition systems, which significantly limit their practicality in portable applications. Herein, a monolithic strain sensor with a multilevel asymmetric architecture is proposed for high-precision direction recognition. The sensor features a capacitor structure composed of a heterogeneous dielectric substrate and two asymmetric capacitor electrodes, enabling simultaneous acquisition of independent resistive and capacitive signals using only three electrodes. By incorporating Ecoflex and Ecoflex-polydimethylsiloxane with a modulus difference exceeding an order of magnitude to construct dielectric substrate featuring heterogeneous sector-shaped structure, significant asymmetric stress distribution is achieved to enhance directional discrimination. Furthermore, a mathematical model is developed to quantify the signal discreteness across various stretching directions, and a data-driven inverse design strategy is employed to efficiently screen 2073600 structures, identifying asymmetric sensing layer configurations with superior direction recognition performance. Assisted by machine learning, the sensor achieves a direction recognition (15 degrees resolution) accuracy of 98.6% and precise strain magnitude (50% range) prediction. Benefiting from its excellent omnidirectional sensing capability, the sensor realizes accurate localization of 12 directional touch points, demonstrating great potential for flexible electronics.

The construction of carbon nanocoil (CNC)-based chiral-dielectric-magnetic trinity composites is considered as a promising approach to achieve excellent low-frequency microwave absorption. However, it is still challenging to further enhance the low frequency microwave absorption and elucidate the related loss mechanisms. Herein, the chiral CNCs are first synthesized on a three-dimensional (3D) carbon foam and then combined with the FeNi/NiFe2O4 nanoparticles to form a novel chiral-dielectric-magnetic trinity foam. The 3D porous CNC-carbon foam network provides excellent impedance matching and strong conduction loss. The formation of the FeNi-carbon interfaces induces interfacial polarization loss, which is confirmed by the density functional theory calculations. Further permeability analysis and the micromagnetic simulation indicate that the nanoscale chiral magnetic heterostructures achieve magnetic pinning and coupling effects, which enhance the magnetic anisotropy and magnetic loss capability. Owing to the synergistic effect between dielectricity, chirality, and magnetism, the trinity composite foam exhibits excellent microwave absorption performance with an ultrabroad effective absorption bandwidth (EAB) of 14 GHz and a minimum reflection of loss less than - 50 dB. More importantly, the C-band EAB of the foam is extended to 4 GHz, achieving the full C-band coverage. This study provides further guidelines for the microstructure design of the chiral-dielectric-magnetic trinity composites to achieve broadband microwave absorption.

Helical carbon coils (HCCs), characterized by their unique chiral structures and exceptional physical properties, have emerged as a frontier research focus stemming from their distinctive electromagnetic wave interaction mechanisms. However, systematic investigations into the circular dichroism (CD) of HCCs remain notably absent in current research. In this work, a comprehensive simulation framework was established to characterize the CD of HCC arrays across the microwave range (2-18 GHz). The impacts of geometric parameters of HCCs, such as the coil diameter, pitch, wire diameter, and coil array period, on the CD have been studied. The simulation results indicate that the increase in the pitch is the optimal adjustment strategy for CD enhancement. In addition, the CD exhibits a non-monotonic dependence on coil length. Most importantly, with the decrease in coil size, the CD diminishes progressively and disappears completely when the coil diameter is reduced to 10.7 mu m. This research provides a guideline for designing chiral HCCs with CD in the microwave range. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International (CC BY-NC-ND) license (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Organic/inorganic thermoelectric (TE) composite fibers are promising for wearable electronics due to their flexibility and energy conversion capabilities, yet their performance remains limited. Here, we have successfully developed novel dual‐interfacial structured poly(3,4‐ethylene dioxythiophene):poly(styrene sulfonate)/single‐walled carbon nanotube@ polyaniline (PEDOT:PSS/SWCNT@PANI) TE composite fibers via wet‐spinning PANI was introduced between SWCNTs and PEDOT:PSS as an interlayer, which not only improved the dispersibility of SWCNTs in aqueous PEDOT:PSS but also facilitated the formation of numerous highly uniform dual‐interfaces at PEDOT:PSS/PANI and PANI/SWCNT contacts.Therefore, the PEDOT:PSS/SWCNT@PANI composite fibers exhibited a high degree of structural alignment and more efficient energy filtering effect. Furthermore, introducing PANI interlayers between SWCNTs and PEDOT:PSS also provided a facile route for finely tuning the carrier concentration of the ternary composite system. With an ammonium hydroxide treatment performed on PANI before fiber spinning, the TE properties of the ternary composite fibers are further optimized. The PEDOT:PSS/SWCNT@PANI composite fibers eventually delivered electrical conductivity of 2472 ± 23.3 S cm −1 and a Seebeck coefficient of 43.5 ± 0.7 µV K −1 . The corresponding power factor reached 467.8 ± 10.5 µW m −1 K −2 , which is remarkably higher than that of other PEDOT:PSS‐based composite fibers. This work domonstrates interfacial engineering as a critical strategy for high‐performance TE fibers, advancing their potential in flexible electronics.

The exceptional advantages of phase engineering inspire the development of advanced microwave absorption (MA) materials. It is a good strategy to modulate phase variation in carbon for optimizing conduction and polarization behaviors. The spiral carbon nanocoil (CNC) with amorphous/polycrystalline phases, which would serve as an ideal template material to investigate the relationship between phase variation and microwave properties. Herein, the crystalline C fraction in CNCs is tunable from 27 % to 53 % via high-temperature annealing-driven phase reorganization of amorphous C, which increases the number of sites of interfacial polarization and further promotes the formation of ordered it-conjugated regions. More importantly, first-principles calculations reveal that a higher crystalline C phase content endows CNCs with richer electronic states and enhanced electron transfer capacity, enabling precise control of electric field distortion. Additionally, the increased interfaces between amorphous and crystalline C introduce intrinsic size and dielectric confinement effects, optimizing relaxation polarization. Benefiting from the synergistic interplay between amorphous and crystalline C phases, the CNC with the ratio crystalline C of 49 % achieves a wide EAB of 6 GHz at a thickness of just 1.9 mm, along with a minimum reflection loss of-49.2 dB. Furthermore, radar cross-section (RCS) simulations confirm that the modulation of phases holds great promise in the field of radar stealth.

Carbon coils (CCs) based microwave absorbing materials (MAMs) have good application prospects in the field of microwave absorption (MA) due to its unique 3D spiral shape, excellent dispersibility and appropriate conductivity. However, CCs are gernerally grown on flat and hard substrates and subsequently be scraped from the substrates. The consumption of substates and the scraping process inevitably increase the preparation cost, which limits the large-scale production and application of CCs. Carbonized toilet paper (CTP) is not only a cheap and efficient MAMs, but also has ability of catalyst loading that makes it suitable as a substrate for CCs growth. Meanwhile, CTP and grown CCs can be used as MAM together without separating them from each other. These largely decrease the production cost. In this work, helical carbon microcoils (CMCs) were successful synthesized on CTP by Ni catalyzed chemical vapor deposition process. CTP and CMCs form an integrated absorbing composite, where the helical CMCs enhance conductive loss and cross polarization loss simultaneously, and the connections between CTP and CMCs induce the interface polarization loss. By precisely controlling the amount of catalyst, the impedance of CTP/CMC is adjusted. The optimized CTP/CMC-10 composite has excellent microwave absorption performance, with an effective bandwidth (reflection loss < -10 dB) of 7.4 GHz and a filling rate of 10 %. This work paves a new way for development of low-cost, broadband, and efficient MAMs.

The integration of multi-dimensional materials is a powerful approach for the construction of high-performance microwave absorbers. In this work, 2D-like carbon microsheets (CMSs) have been directly synthesized on the surfaces of 3D helical carbon nanocoils (CNCs) through a Cu catalyzed chemical vapor deposition process. The junctions formed between CMSs and CNCs create numerous polarization sites, which enhances interfacial polarization. The planar morphology of CMSs is beneficial to enhance the multiple scattering of microwave, while the 3D helical CNCs prevent the aggregation of 2D-like CMSs and simultaneously enhance the conductive loss and cross-polarization loss. By controlling the growth time, the morphologies of CMS are precisely tailored and their impedance matching is adjusted. Consequently, CMS/CNC demonstrates exceptional microwave absorption (MA) performance with a broad effective bandwidth of 6.5 GHz and a minimum reflection loss of -39.3 dB at a remarkably low filling ratio of 4 wt%. This study provides a novel multi-dimensional integrated structure for efficient MA.

The exploration of smart microwave (MW) absorption materials with excellent mechanical properties and wide frequency tuning ability is challenging work. Herein, an ultra-flexible MW absorber with wide frequency modulation by itself strain sensing has been successfully constructed, which is realized by introducing doped conductive poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) with dimethyl sulfoxide (DMSO) into three-dimensional melamine foam (MF) network. The formed MF/P-D20 composite itself is a piezoresistive sensor with a high sensitivity. Most importantly, it is found that the absorption frequency band of the MF/P-D20 composite film can be controllably and reversibly modulated in a wide frequency range from S to Ku bands by changing the compression strain monitored by the value of ΔR/R0. Furthermore, theoretical simulations and experimental findings confirm that the variations of pore shape and size after compression serve as a crucial factor responsible for shifting the enhanced electron flux density and MW loss to higher frequency, which consequently induces the shift of impedance matching and sequent MW absorption to higher frequency. The MW absorber also shows excellent properties of mechanical robustness, thermal insulation, electro-thermal conversion and retardant. This study provides insights into the smart and reversible control of MW absorption properties and paves the way for tuning MW absorption frequency in wide frequency.

The elastic composite aerogels based on two-dimensional transition metal carbides/nitrides/carbonitrides (MXene) hold significant potential as high-performance multifunctional materials for sensors and energy storage devices, but they are still plagued by the issues of brittleness and unsatisfactory conductivity. Herein, aiming to address these problems,we have combined Ti3C2TX MXene with poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) as a conductive adhesive and spring -like carbon nanocoils (CNCs) as crosslinking chains to construct hyperelastic aerogels through the directional freeze-casting technique. The MXene/ PEDOT:PSS/CNC aerogels feature an anisotropic layer-strut cellular structure. Benefiting from this unique structure, the aerogels exhibit impressive mechanical property, achieving a maximum resilient strain of 80 % (corresponding 64.3 kPa). The piezoresistive sensors based on the aerogels perform a high sensitivity of 0.23 kPa-1, a low detection limit of -45 Pa, and a stable long-term sensing of over 5000 cycles. The aerogels can also work as excellent electrode materials, displaying a high specific capacitance of 134.5 F g-1 at 0.5 A g-1 and superior rate performance. Furthermore, the assembled compressible supercapacitor shows stable electrochemical performance with compressive strain increasing from 0 to 80 %. The designed MXene/PEDOT:PSS/CNC aerogels are expected to serve as novel multifunctional platforms for thermal insulation, shock absorption, sensitive strain detecting, and highly stable compressive energy storage.

The fabrication of carbon nanocoil (CNC)-based chiral-dielectric-magnetic trinity composites holds great significance in low-frequency microwave absorption fields. However, it is not clear that how the different magnetic systems affect the magnetic and frequency responses of the composites. Herein, four types of magnetic metals, FeCo, CoNi, FeNi, and FeCoNi, are selected to be combined with the chiral templates respectively, resulting in four types of chiral-dielectric-magnetic composites with similar morphology. The CNC templates endow all the composites with excellent dielectric loss. Further permeability analysis and the micro-magnetic simulation confirm that the frequency response region can be well adjusted by changing the magnetic systems with specific magnetic resonance modes and magnetic domain motion. Due to the synergistic effect between magnetism, chirality, and dielectricity, the FeNi-based composites exhibit the best low-frequency microwave absorption performance. The minimum RL of -60.7 dB is achieved at 6.7 GHz with an ultra-low filling ratio of 10%, and the EAB value in low-frequency region is extended to 3.7 GHz. This study provides further guidelines for the design of the chiral-dielectric-magnetic trinity composites in low-frequency microwave absorption. Four types of magnetic metals, FeCo, CoNi, FeNi, and FeCoNi, are selected to be combined with the chiral templates respectively, resulting in four types of chiral-dielectric-magnetic composites. Due to the synergistic effect between magnetism, chirality, and dielectricity, the FeNi-based composites exhibit a wide low-frequency absorption bandwidth of 3.7 GHz with an ultra-low filling ratio of 10%. image

Carbon fiber reinforced thermoplastic/aluminum alloy (CFRTP/AL) composite laminates have the advantages of low density, high specific strength, and good fatigue resistance, which is a new type of engineering composite material to realize lightweight vehicle body. Heterogeneous interface delamination failure occurs in the forming process of the fiber metal laminates (FMLs). It is necessary to establish an effective finite element simulation strategy to accurately predict the delamination failure behavior of FMLs. In this work, thermoplastic PA6 continuous carbon fiber/AL FMLs were taken as the research object, and the double cantilever beam (DCB) and the end-notched flexure (ENF) experiments were carried out to determine the basic mechanical parameters between the interlayer interfaces of CFRTP/AL. Furthermore, a numerical simulation model based on ABAQUS software was developed to describe the progressive damage failure behavior of the CRFTP/AL in the forming process by using the equivalent modeling strategy of discontinuous micro-shear, which realized the effective prediction of ply directional damage failure of FMLs on the basis of the S-beam model. The results show that the established damage constitutive model and numerical method coupled with cohesive zone model (CZM) can effectively predict the ply directional damage failure behavior of CFRTP/ AL composites during the large deformation forming.

Ingenious microstructure design and rational composition collocation have been proved to be an effective strategy for developing efficient electromagnetic wave (EMW) absorbers. It would be promising to fabricate a hollow structured composite integrating multiple loss mechanisms (conduction, magnetic, and polarization losses) for excellent EMW absorption. Herein, a novel dielectric -magnetic compound of ZnO/Ni@C hollow microsphere was prepared through hydrothermal reactions followed by an in -situ chemical vapor deposition (CVD). In this ternary composite, abundant ZnO/Ni heterostructures formed the hollow microsphere skeletons and provided unique Schottky junctions, which endowed the composite with improved impedance matching and strong polarization loss. Meanwhile, the amorphouspolycrystalline carbon layer deposited on the surface of each microsphere enhanced the conduction and interfacial polarization losses. In addition, the magnetic Ni nanoparticles induced magnetic loss. Benefiting from the synergistic effect of the hollow structure and multiple loss mechanisms, the ternary composite exhibits an effective absorption bandwidth as wide as 6.55 GHz at a thickness of only 1.85 mm, accompanied by a minimum reflection loss of -39.8 dB. Besides, the radar cross-section and the electromagnetic field simulation further verify the superior EMW absorption performance of the composites. Our work provides a new reference for the fabrication of dielectric -magnetic ternary hollow microspheres as EMW absorbers with thin thickness and broad bandwidth. (c) 2024 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

The exceptional benefits of structural defects and doped atoms in carbon network regarding electromagnetic properties inspire the design of advanced carbon-based microwave absorption (MA) materials. However, excessive structural defects decline the physical properties of materials, especially their conductivity. Therefore, it is a great challenge to balance structural defects and doped atoms to optimize conductive behavior for carbon-based MA materials. The spiral carbon nanocoil (CNC), with coexisting amorphous and polycrystalline carbon structures and moderate conductivity, has significant MA properties but lacks pores and doped atoms. Herein, the amorphous carbon parts with relatively weak C & horbar;C bond energies are preferentially oxidized at 500 degrees C in air atmosphere to create pores and combine O atoms in the bodies of CNCs. Furthermore, the mechanism prioritizing the formation of O doping over defects is discovered. Benefiting from the synergistic interplay of structural defects and O dopants, the O-enriched porous CNCs demonstrate enhanced conduction and polarization losses than the pure CNCs, realizing a wide effective absorption bandwidth of 7.3 GHz at a filling ratio of only 3 wt.%. Theoretical calculations further support these experimental results. The combination of structural defects and doped atoms may serve as an effective pathway for unlocking tunable dielectric properties of carbon-based materials. The amorphous carbon parts with relatively weak C & horbar;C bond energies are preferentially oxidized at 500 degrees C in air atmosphere to create pores and combine O atoms in the bodies of CNCs. The porosity and O atom doping ratio are effectively modulated by the oxidation time. Benefiting from the synergistic interplay of structural defects and O dopants, the O-enriched porous CNCs demonstrate enhanced conduction and polarization losses than the pure CNCs, realizing a wide effective absorption bandwidth of 7.3 GHz at a filling ratio of only 3 wt.%. Theoretical calculations further support these experimental results. image

Fundamental understandings of the relationship between ion-electrode interaction and structural feature in porous carbon electrodes at a molecular level provides guidelines for the design of high-performance electric double layer supercapacitors. It is certified by experiments that porous carbon structures doped with nitrogen show enhanced capacitive performance. However, in the theoretical simulations, the fundamental charge storage mechanism is still elusive. In particular, the recent experimental result shows that the generally ignored nitrolic nitrogen (N5) in porous carbon exhibits a positive effect on capacitance, while graphitic nitrogen (N3) does the opposite, which is against with the simulation results based the 2D-modeled porous graphene structure. Here, we perform ab initio molecular dynamics simulations on the N3 and N5-doped carbon /electrolyte interfaces, including both 2D planar and 3D microporous carbon electrodes. Our calculation indicates that N3 in the 3D pore hinders the electrolyte transport, while N5-doped micropore still serves as an electrolyte transport channel through the formation of H-bond. The charge storage mechanism is further elucidated by the analysis of the well equilibrated interfaces obtained from the machine learning force field accelerated molecular dynamics. Our work provides a new insight into the effect of nitrogen doping in 3D porous carbon, which is exactly opposite to the 2D planar graphene. Therefore, we emphasize that differences in the electrochemical conditions of 2D planar and 3D microporous carbon electrodes should be fully considered when analyzing the effects of surface chemistry on charge storage mechanisms.