High Energy Density Supercapacitors Research Articles

Exploratory mass dispersoid rGO in-situ influence on nickel phosphate-trimesic acid metal-organic framework for higher energy density hybrid supercapacitors

The present study investigates effect of reduced graphene oxide (rGO) mass dispersoid @ 25, 50, 75, and 100 mg through in-situ process into Metal Organic Framework based Nickel Phosphate (MOFNP) synthesized by facile microwave technique. The XRD study confirms monoclinic crystalline geometry and 50 mg rGO dispersed MOFNP (MOFNPG2) composite has shown increase in crystallinity. SEM shows rectangular morphology for MOFNPG2 and Raman studies show ID/IG ratio of 1.01 for this composite revealing rGO coordination with MOFNP. BET studies reveal higher specific surface area (59.75 m2 g−1) for MOFNPG2 and exhibits mesoporosity (3.14 nm) with type-IV Langmuir isotherm. The deconvoluted XPS spectra confirms oxidation states and chemical compositions of MOFNPG2. The CV profile identifies maximum oxidation for MOFNPG2, revealing EDLC / pseudocapacitance contribution and exhibiting higher specific capacitance of 854 F g−1 @ 1 A g−1. The Full-Cell Device (FCD) MOFNPG2//rGO registers 175 F g−1 @ 1 A g−1 and energy density 79 Wh kg−1. The Resr is lower (0.19 Ω cm−2) for FCD which improvises electrode-electrolyte kinetics and results in enhanced conductivity for high energy density supercapacitor applications.

Electrospun carbon/iron–vanadium oxide nanofibers for high energy density supercapacitors

Highly flexible and conductive carbon nanofibers (CNFs) embedded with pseudocapacitive iron–vanadium oxide (FVO) nanoparticles were fabricated via electrospinning of a metal salt/polyacrylonitrile solution followed by high-temperature annealing (750 °C). CNFs have a graphitic structure with defects, which could accelerate electron mobility and the access of electrolytic ions to the multivalent FVO nanoparticles, respectively. Poly(methyl methacrylate) (PMMA) was introduced as a sacrificial polymer to alter the internal structure of the nanofibers and thus enhance the electrolytic ion transport pathways. Terephthalic acid was added to provide flexibility by increasing the cross-linking within the electrospun fibers. The flexible FVO/CNFs exhibited excellent electrochemical performance. The optimal sample had a high areal capacitance of 1058 mF·cm−2 at a current density of 2.5 mA·cm−2 and showed 100 % capacitance retention during long-term cycling (10,000 cycles). The capacitance at a high current density of 25 mA·cm−2 was 81.3 % of that at a current density of 2.5 mA·cm−2. Using a wider potential window of 0–1.6 V increased the energy density to 389 μW·h·cm−2. The optimal FVO/CNF sample maintained 90 % of its initial capacitance after 200 bending cycles.

MnO2-decorated flexible carbon nanofibers with controllable hierarchical porous nanostructures for high energy density supercapacitors

Constructing hierarchical porous structures and reducing material size enhance the electrochemical efficiency of porous carbon-based electrodes. In this study, ultrafine hierarchical porous carbon-based nanofibers were synthesized via electrospinning a blend of polyacrylonitrile, polymethyl methacrylate (PMMA), and zinc acetate dihydrate (ZAH), followed by pre-oxidation, carbonization, and acid washing. Adjusting the ZAH content allowed precise control of fiber diameters (300-600nm) and promoted significant hierarchical porous structures, achieving an optimal mesopore to micropore ratio (1.65) and a high specific surface area (SSA) of 599 m²/g. MnO2 nanosheets were in-situ modified on the carbon nanofibers, forming a hybrid electrode (MnO2@HPCNFs) with excellent flexibility, high SSA value, and rich pore structure. This electrode demonstrated a specific capacitance value equal to 1035 F/g at 0.5 A/g and maintained 80.7% capacitance at 10 A/g. The assembled asymmetric supercapacitor achieved an energy density of 54.81 Wh/kg. This study presents new possibilities for binder-free, self-supporting electrodes in electrochemical energy storage devices.

An environment-friendly method to prepare fulvic acid-based porous carbon for high energy density supercapacitors

Low energy density (Eg) of supercapacitors (SCs) severely limits their industrial applications. Enhancing the voltage window of SCs is an effective method to achieve a square-fold increase in Eg. 3D hierarchical porous carbons (FPs) with high yield (14.5 %) and high conductivity (87 S m−1) were prepared by an interfacial self-assembly method using low-cost biomass fulvic acid (FA) as a carbon resource and employs P123 as a structure-directing agent. The soft template P123 establishes a key role in the formation of FPs. It not only enhances the pore connectivity of FPs but also induces an interfacial orientation of the carbon micro-domains in FA. Furthermore, high-temperature annealing can repair the carbon network of FPs, thus FPs are endowed with high electrical conductivity, low carbon defects and low oxygen content (4.1 at.%), which leads to superior voltage-withstanding properties. By exploiting its structural advantages, the optimized sample FP800 exhibits a specific surface area of 1938 m2 g−1, sp2 carbon (88.5 %), a high mesopore ratio of 30.76 % and a high voltage of 3.2 V in commercial TEABF4/PC electrolyte. It gets high Cg of 107 F g−1 at 1 A g−1, high rate performance (C10/0.05) of 82.0 % and maximum Eg of 39.1 Wh kg−1. Furthermore, it also obtains an ultra-stable lifespan with 90.6 % capacity retention after 60,000 cycles. Compared to FP750 and FP850, FP800 has a more reasonable electrochemical performance.

Corn Husk Derived Activated Carbon/Siloxene Composite Electrodes based Symmetric Supercapacitor with High Energy Density and Wide Temperature Tolerance

AbstractIn the present work, novel composite material comprising of corn husk derived activated carbon and siloxene nanosheets have been explored as new class of multicomponent electrode material for fabricating high energy density supercapacitors with wide temperature tolerance. The activated carbon obtained from corn husk (ACH–900) with high surface area and pore volume acts as an ideal framework for hosting siloxene nanosheets (S) that allows the overall siloxene–corn husk derived activated carbon (ACH–900/S) composite to deliver excellent electrochemical performance. The as‐prepared ACH–900/S composite electrode exhibited a high specific capacitance of 415 F g−1 at 0.25 A g−1 and retained 73.4 % of its initial capacitance even at a high current density of 30 A g−1 in 1 M Na2SO4 electrolyte. In addition, the symmetric supercapacitor assembled with “acetonitrile/water‐in‐salt (AWIS)” electrolyte exhibited an energy density of 57.2 W h kg−1 at 338 W kg−1 with a cyclic stability of 92.8 % after 10000 cycles at 5 A g−1 current density. Besides, the fabricated ACH–900/S supercapacitor can operate over wide temperature range from 0 to 100 °C. This work opens up new frontiers to develop low‐cost safe supercapacitors with wide temperature tolerance and excellent electrochemical performance.

Cobalt-ions pre-intercalation MnO2 nanosheet arrays on nickel foam achieving boosted electrochemical pseudocapacitance for supercapacitors

Metal oxide have attracted much attention as a pseudocapacitive electrode for high energy density supercapacitors (SCs). However, the battery-like charge storage mechanism based on ions diffusion and valence change for metal oxide would lead to a poor cycling stability and unsatisfied rate performance. Herein, cobalt ions pre-intercalation MnO2 nanosheet arrays on Ni foam (Co-MnO2/NF) was prepared as the cathode for SCs. The capacitive behavior of MnO2 was enhanced via cobalt introduction. The optimized Co-MnO2/NF-2 demonstrated improved pseudocapacitance and stability, with a specific capacitance of 405.6 mF cm−2 at 1 mA cm−2. It retained 90.5 % of its initial capacitance at 10 mA cm−2 after 5000 cycles, which was superior to that of pristine MnO2 (222.4 mF cm−2, 65.0 % after 1000 cycles), Co-MnO2/NF-1 (295.2 mF cm−2, 85.9 % after 1000 cycles), and Co-MnO2/NF-3 (349.9 mF cm−2, 84.9 % after 1000 cycles). The asymmetric aqueous supercapacitor consisted of Co-MnO2/NF-2 and N-doped porous carbon fiber (NPCF) electrodes with an operating potential of 2.0 V reaches a high areal energy density of 0.06 mWh cm−2 at a power density of 0.5 mWh cm−2.

Recent progress of high-energy density supercapacitors based on nanostructured nickel oxides

With the progressive demand of portable devices and hybrid electronic vehicles, relevant energy storage options are one of the most important practical necessities. Supercapacitors may play a key role for developing auto electronic advanced tools, because of their specific power density, fast charging capacity, and long-life time. On the other hand, nanostructured materials for supercapacitor electrodes have demonstrated great potential for constructing a reliable as well as efficient gateway for betterment. Nanostructured form of metal oxides, especially nickel oxide (NiO), is one of the most excel material to design high performance supercapacitors. This review deals with a detailed discussion on some fundamental aspects of supercapacitors incusing variety, performance evaluation criteria, and influencing factors for designing high density supercapacitors. Along with these, recent effective strategical approaches for generating high energy density supercapacitors utilizing NiO and their composites are particularly described the inherent performance influencing factors like their physical, chemical, and compositional variations. Finally, upgrading the next generation devices, the commercial application, challenges, and future prospects of the recently developed NiO-based supercapacitor materials are pointed out.

In‐Plane heterostructured FeCoS@NiCo-LDH nanosheets with improved interfacial charge transfer for hybrid supercapacitors

Engineering a heterogeneous structure with distinctive morphology and nanostructure is deemed to be an efficacious tactic for realising high energy density supercapacitors (SCs). Herein, the FeCo2S4@NiCo-LDH(FeCoS@NiCo-LDH)/NF nanocomposite heterostructure is successfully constructed through a facile two-step electrodeposition method. This heterostructure merges the merits of FeCoS with high electrical conductivity and NiCo-LDH with ultra-high specific surface area, which not only can deliver sufficient electroactive central sites, but also provide shorter routes for expedited ion diffusion, even more significantly, the heterogeneous interfaces that emerge in composites can moderate their electronic structure and augment electrical conductivity. Density functional theory (DFT) calculations indicate that the heterostructured FeCoS@NiCo-LDH/NF displays preferable electrochemical activeness and enhanced adsorption ability. Thanks to the abundance of heterogeneous interfaces and synergistic effects of the various active ingredients, FeCoS/NiCo-LDH electrodes exhibit an extraordinary specific capacity of 930 C g−1 at 1 A g−1 together with remarkable cycle longevity (10.9 % capacity decay after 10,000 cycles). In addition, a hybrid FeCoS@NiCo-LDH/NF//AC exhibits a high energy density of 52.81 Wh kg−1 at the 750 W kg−1.

Pyrolytic conversion of Mesua ferrea testa to nitrogen-doped porous carbon for supercapacitor applications

Developing a high energy density supercapacitor is of great challenge due to the low surface area of commercial activated carbon. The present work aims at developing highly porous nitrogen-doped porous carbon from biomass for supercapacitors. Herein, Mesua ferrea (Nahor) shells, a widely available biomass in northeast India, was used to prepare porous carbon. The effect of activation temperature on structural, textural properties, and electrochemical performance is studied. The carbonization temperature highly influenced the pore structure, porosity, surface area, and thereby influencing the electrochemical performance. The porous carbon pyrolyzed at 700 °C delivered a high specific capacitance of 210 F g-1 at 1 A g-1, higher than porous carbon made at higher temperature (27.5 F g-1 at 1 A g-1 for carbon pyrolyzed at 800 °C). The results provide insights that will be of use in the development of high-energy-density capacitors employing biomass-derived porous carbon.

Zn-based coordination polymer derived N-doped defective carbon for high energy density supercapacitor using aqueous, dual redox additive and ionic liquid electrolytes

Porous carbons are excellent supercapacitor materials due to their high-power density, rapid charge-discharge rates and extended cycling stability. However, the restricted energy density poses a bottleneck for their practical applications. The ideal approach to enhance the energy density is by utilizing redox additives and ionic liquid electrolytes. Herein, the defect-rich nitrogen-doped porous carbons (N-PCs) are synthesized at 700, 850 and 1000 °C using Zn-BTC BPY coordination polymers as the sacrificial template for high energy density supercapacitor application. The defect density increases while the percentage of N-doping decreases with the increase in carbonization temperature. In three-electrode system, N-PC-1000 carbon delivered a high capacitance of 151 F g-1 at 1 A g-1, whereas N-PC-700 and N-PC-850 carbons delivered capacitance of 129 and 87 F g-1, respectively, with more than 98% capacitance retention. Additionally, the N-PC-1000||N-PC-1000 symmetric coin cell device delivered high energy densities of 14.2 and 16.9 Wh kg-1 in organic (KOH + HQ) and inorganic-organic dual redox additive (KOH + KI + HQ) electrolytes, respectively. Further, the assembled symmetric device demonstrated maximum energy and power densities of 31.3 Wh kg-1 and 15,881 W kg-1, respectively in [EMIM][ESO4] ionic liquid electrolytes, while retaining 99 % capacitance over 6000 GCD cycles. Overall, this study presents the idea of using coordination polymer-based porous carbons for developing next generation energy storage devices.

Two-electron sulfonyl(trifluoromethanesulfonyl)imide-anthraquinone redox electrolytes for high-energy density supercapacitors

Organic redox electrolyte-enhanced electrochemical double layer capacitors (ORECs) are potentially better solution for combining both high power and energy density. The critical factor of ORECs is to develop high-performance organic redox electrolytes. Anthraquinone (AQ) derivatives are the promising organic redox electrolyte candidates because of their low redox potential and fast two-electron redox kinetics. Low solubility and poor longevity in aprotic solvents of charged AQ species are main issues for effective enhancement. Here we report two-electron redox ionic compounds by functionalizing AQ with a robustly electron-withdrawing sulfonyl(trifluoromethanesulfonyl)imide (AQSTFSI) anion and pairing counter monovalent cations for high-performance ORECs. The highly electron-conjugate substitute markedly stabilizes the radical and 2e−-charged forms of AQ by decentralizing the electron density of the CO heads, preventing the adverse reaction of electrophilic/nucleophilic attack, revealing by theoretical simulation. Also, the STFSI− substituent enables AQSTFSI-compounds significantly improved solubility, thermostability, and redox reversibility. Consequently, the AQSTFSI-K applied in OREC shows all-roundly superior performance containing 3.2 V cell voltage, specific energy of 58 Wh kg−1 with 1.8 times of corresponding electrochemical double layer capacitors (EDLCs), specific power over 8 kW kg−1, cycling stability over 12,000 cycles, low self-discharge, and wide working-temperature range. This molecular strategy grounded on electron density modulation of redox electrolyte structures provides valuable insights into the design for high-performance ORECs in practical applications.

High volumetric performance of functional carbon material enabled by co-pyrolysis of mango branches and Faradaic active N-enriched doping

Restricted by the poor volumetric performance, biomass-based supercapacitors are challenging to meet the rapid development of miniaturization and portability of energy storage devices, and the Faraday active nitrogen-doping strategy proves to be an efficient approach to address this concern. This study successfully synthesizes functional carbon materials with significant Faraday activity through a straightforward and environmentally friendly co-pyrolysis method. Mango branches served as the primary raw material, NH4B5O8∙4H2O acted as a template, and NH4Cl and NH4B5O8∙4H2O were utilized as the multiple nitrogen-enriched agents. A surface micro-NH3 environment can be achieved by modulating the addition of NH4Cl, and the decomposed NH3 is adsorbed on the biomass surface by the electrostatic adsorption of NH4B5O8∙4H2O. MA1.5N1.5-T700 showcases a compact self-supported structure with micro/mesopores, boasting a substantial nitrogen content of 2.95 %. It achieves a notable volumetric capacitance of 320 F/cm3 (368 F/g) at 0.5 A/g and maintains an exceptional rate performance of 72.9 % at 20 A/g. The constructed symmetrical supercapacitor also reveals an ultra-high energy density of 13.01 Wh/L (14.95 Wh/kg) and an impressive capacitance retention of 94.03 % undergoing 10,000 cycles. This study offers theoretical insights into fabricating electrode materials for high volumetric energy density supercapacitors through the pyrolysis of forestry waste.

Synthetic nanoarchitectonics with ultrafast Joule heating of graphene-based electrodes for high energy density supercapacitor application

This study presents a novel approach for the development of high-performance supercapacitor (SC) electrodes using the Flash Joule Heating (FJH) method. Here, we report a direct and rapid synthesis of graphene-based electrodes via FJH. The technique involves microwave-assisted decomposition of citric acid and urea to form CNDs as precursors, followed by Flash Joule Heating (FJH) leading to the formation of graphene in seconds. The scalability of this method paves the way for the rapid production of graphene-based SC electrodes. Based on the characterisation using XRD, Raman, SEM and TEM, the FJH-treated CNDs yielded graphene on carbon fibre cloth with well-defined morphologies leading to superior electrochemical performance in supercapacitors. The FJH processed electrodes exhibited exceptional electrochemical performance with a specific capacitance of 279 F g⁻¹ at 1 A g⁻¹, significantly outperforming unflashed and low current flash processed electrodes. This exceptional performance can be attributed to the formation of high-quality, few-layered graphene with enhanced electrical conductivity and efficient ion transport properties. Moreover, a Symmetric supercapacitor is also assembled which demonstrated a specific capacitance of 106.5 F g⁻¹ at 1 A g⁻¹. It also exhibited an impressive energy density of 44.4 W h kg−1 at a power density of 1000 W kg⁻¹. This work demonstrates the feasibility of FJH as a rapid, scalable and cost-effective technique for the production of high-performance graphene-based electrodes for supercapacitor applications.

Enhancement of energy density for iron MOF-derived composite for aqueous supercapacitor by K3[Fe(CN)6] redox additive electrolyte

Redox additive added aqueous electrolyte attract extensive interest in supercapacitor application. Herein, the electrochemical of the synthesized Fe3O4/Si/GNP composite cathode electrode material was conducted in a two-electrode system via Swagelok cell assembly in the presence of with and without redox additive (0.2 M K3Fe(CN)6 in 1 M Li2SO4). The Fe3O4/Si/GNP composite was successfully synthesized by facile solvothermal method followed by calcination. The structural and morphology investigations of the Fe3O4/Si/GNP composite are conducted via XRD, FESEM, and BET analyses. The synergic effects between the composite material and redox-active ion (Fe2+/Fe3+) in the redox additive electrolyte enhance faradaic reactions, which are utilized to design a high-energy density supercapacitor. The Fe3O4/Si/GNP composite in redox additive electrolyte exhibits a 64.38 % increase in specific capacitance (319.45 F g−1 at 1 A g−1) and a 70.95 % increase in terms of energy density (35.56 Wh kg−1). Redox additive ions in the electrolyte enhance ionic conductivity and facilitate electron transfer across the porous structure of the Fe3O4/Si/GNP composite. The fast reversible kinetics of iron ions enable it to sustain decent cycle stability with a capacitance retention of 73.7 % after 1200 cycles.

Engineering the electrochemical performance of CoWO4 composites of MXene by transitional metal ion doping for high energy density supercapacitors

Engineering the electrochemical performance of CoWO4 composites of MXene by transitional metal ion doping for high energy density supercapacitors

Heteroatom(S) (N, S, P) Co‐Doped Reduced Graphene Oxide‐Based Binder‐Free Novel Energy Storage Electrode Material for High Energy Density Supercapacitor

AbstractThis manuscript reports a one‐pot synthesis of ternary heteroatoms (N/S/P) co‐doped reduced graphene oxide as an electrode material by simultaneous reduction/doping of/into graphene oxide employing eco‐friendly natural molecule(s) (thiamine monophosphate (TM) and thiamine pyrophosphate (TP)) under mild heating (≤60 °C) and near‐neutral pH (≤8) conditions. It produces N, S, P co‐doped rGO‐TM and N, S, P co‐doped rGO‐TP nanohybrids displaying a well‐connected porous microstructure with significantly doped atomic(%) ‐N (10.0%), S (4.1%), P (0.1%) and N (6.7%), S (2.0%), and P (0.5%), respectively. The symmetric supercapacitor designed using N, S, P‐rGO‐TM‐10 in water‐in‐salt 17 m NaClO4 electrolyte exhibits stable cell voltage of 3.0 V, superb gravimetric energy density (areal energy density) of 47.9 Wh kg−1@522.8 W g−1 (0.2363 Wh cm−2@ 2.5 W cm−2); the excellent cyclic stability (88.8 %) and Coulombic efficiency (99.2%) even after 20 000 cycles. Their energy storage capability is corroborated by the illumination of 109 white LEDs upon lighting a single SSC for 50 s each, driving a motor to run a fan, and forming the tandem device by joining three such cells in series.

Structural energy storage composites based on etching engineering Fe-doped Co MOF electrode toward high energy density supercapacitors

Metal organic frameworks (MOFs) have been used widely as cathode materials for supercapacitors because of their adjustable chemical composition, variable topological structures, and relatively simple synthesis methods. However, most MOFs are insulated and their metal organic ligand coordination bonds are not stable enough in electrolytes, which greatly limits the application of MOFs in supercapacitors. The synergistic effect between transition metal doped and chemical etching is of great significance for the preparation of high-performance MOF electrodes. This study introduces Fe into Co MOF prepared by co precipitation to optimize the electronic structure of Co, and then constructed e-Fe-doped Co MOF hierarchical structure through ammonia etching. The Co MOF achieves rapid electron exchange at the electrode electrolyte interface through this synergistic effect, improving conductivity, and increasing specific surface area, exposing more active sites, effectively enhancing the electrochemical activity of the electrode. Therefore, the e-Fe-doped Co MOF-4 h has a high specific capacity of 700 C g−1 at 1 A g−1 with a 90.08 % high-rate performance. The assembled e-Fe-doped Co MOF-4 h//N-doped WC ASC provides the energy density of 80 Wh kg−1 at a power density of 800 W kg−1 with a ∼88 % capacitance retention after 10000 cycles. These results provide ideas for utilizing synergistic effects to prepare high-energy density supercapacitors using MOF materials.

Preparation of N and O doped coal tar pitch based porous carbon for supercapacitor electrode

Coal tar pitch (CTP) is mainly composed of a mixture of polycyclic aromatic hydrocarbons, is almost hydrophobic, and has a low heteroatom content, which limits its surface function. During carbonization, it is prone to condensation and difficult to form pore structures, resulting in poor electrochemical performance for carbon electrode materials. Herein, nitrogen (N) and oxygen (O) doped hierarchical porous carbon (C-ANOCTP) was prepared by HNO3 oxidation and KOH activation using CTP as carbon precursor. The oxidation of HNO3 remarkably increases the hydrophilic functional groups containing N and O on the surface of CTP, improves the hydrophilicity of CTP surface, facilitates the activation process of KOH, promotes the development of carbon material pore structure and the generation of active sites, as well as the formation of defect structures. The specific surface area of C-ANOCTP obtained is 1130 m2/g, with O content of 10.29 at% and N content of 2.37 at%. The specific capacitance of C-ANOCTP in a three-electrode system with 6 M KOH electrolyte is as high as 410.51 F/g at 0.5 A/g. A symmetric supercapacitor is assembled in a 6 M KOH electrolyte using C-ANOCTP as electrode. When the power density is 25 W/kg, the energy density is 10.24 Wh/kg. After 10,000 cycles, the capacitance retention rate is still 90.03% and the coulomb efficiency is 100%. The high N and O content of porous carbon is prepared by simple HNO3 oxidation synergistic KOH activation and low temperature carbonization, which shows excellent electrochemical properties in supercapacitors, making CTP an ideal candidate material for high energy density supercapacitors.

Simple preparation of V-doped NiCo-LDH as cathode of high energy density supercapacitor

One of the most promising cathode materials for supercapacitors is nickel-cobalt layered double hydroxide (NiCo-LDH). Doping atoms are widely used to solve the problems of poor electrical conductivity and structural defects of electrode materials. Vanadium (V) has received widespread attention due to its multiple oxidation states and low cost. In this article, we use one-step hydrothermal method to synthesize V-doped NiCo-LDH (V-NC1.5). By regulating the doping amount of V, 2V-NC1.5 exhibits superb specific capacitance of 1835 F g−1 at 1 A g−1. An asymmetric aqueous supercapacitor was assembled with 2V-NC1.5 and activated carbon. Its maximum energy density can reach 60.9 Wh kg−1 at 800 W kg−1 of power density. When the two units are connected in series, they can effectively power a white LED bulb and maintain its brightness for more than 30 min. This result provides a potential opportunity for the efficient deployment of innovative energy storage technologies in the coming years.

Armoring hydrophilic wood-structured ultrathick electrode with bimetallic nitride enables high energy-density supercapacitor

Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities. Unfortunately, traditional slurry-casting electrodes induce high-tortuous ionic diffusion routes that directly depress the capacitance with a thickening design. To overcome this, a novel 3D low-tortuosity, self-supporting, wood-structured ultrathick electrode (NiMoN@WC, a thickness of ∼1400 μm) with hierarchical porosity and artificial array-distributed small holes was constructed via anchoring bimetallic nitrides into the monolithic wood carbons. Accompanying the embedded NiMoN nanoclusters with well-designed geometric and electronic structure, the vertically low-tortuous channels, enlarged specific surface area and pore volume, superhydrophilic interface, and excellent charge conductivities, a superior capacitance of NiMoN@WC thick electrodes (∼5350 mF cm−2 and 184.5 F g−1) is achieved without the structural deformation. In especial, monolithic wood carbons with gradient porous network not only function as the high-flux matrices to ameliorate the NiMoN loading via cell wall engineering but also allow fully-exposed electroactive substance and efficient current collection, thereby deliver an acceptable rate capability over 75% retention even at a high sweep rate of 20 mA cm−2. Additionally, an asymmetric NiMoN@WC//WC supercapacitor with an available working voltage of 1.0–1.8 V is assembled to demonstrate a maximum energy density of ∼2.04 mWh cm−2 (17.4 Wh kg−1) at a power density of 1620 mW cm−2, along with a decent long-term lifespan over 10,000 charging-discharging cycles. As a guideline, the rational design of wood ultrathick electrode with nanostructured transition metal nitrides sketch a promising blueprint for alleviating global energy scarcity while expanding carbon-neutral technologies.