Electrochemical Performance For Supercapacitors Research Articles

2D sheet to 1D rod-like morphology regulated self-assembled ZnCo2O4 microstructures under mixed solvent conditions for battery-type supercapacitors

This study examines the effects of the mixed solvent's characteristics on the nucleation and crystal growth processes and the surface morphologies of zinc cobaltite (ZnCo2O4; ZCO) microstructures. We discovered that the number of interaction sites in ZCO microstructures significantly increases when the solvent changes. This influences the material's high crystallinity, phase purity, morphology, and significantly influences its electrochemical conductivity. One with deionized (DI) water and ethanol mixed solvent and the other with DI water and ethylene glycol (EG) to produce mesoporous ZCO with rod-like and sheet-like microstructures, respectively. The ZCO-R delivered a high specific capacity of 468.5 C g−1 (130.13 mAh g−1) at a current density of 1 A g−1 compared to the ZCO-S (351 C g−1 / 97.5 mAh g−1). Additionally, the ZCO-R microstructures showed good rate performance (82% of its initial capacity) and cyclic stability (90% of capacity retention after 5000 cycles) due to their higher surface area and mesopore features. Hence, utilizing mixed solvent conditions to design morphology-controlled electrode materials is a promising approach to enhancing the electrochemical performance of battery-type supercapacitors.

Engineering interfaces to facilitate charge transport pathways in electrospun scaffolds for high-performance, flexible supercapacitors

Understanding and engineering the interface of a polymeric matrix with the ionic conductor offers important insights into the electrochemical charge polarization performance of flexible solid-state supercapacitors. These aspects are captured herewith utilizing chemically identical yet morphologically and interfacially different and distinct non-woven, electrospun polymeric membranes as scaffolds. Three distinct variations achieved through electrospinning namely, bilayered (PU/Ge) and core-shell geometries (PU@Ge and Ge@PU) with polyurethane (PU) and gelatin (Ge) are utilized in both conditions as polymeric electrolyte membranes for flexible supercapacitors. Equally important is the unique graphenic nanoplatelets (GNPs), fabricated through a single-step, template-driven approach, providing synergistic electrode/electrolyte interfaces. We unravel distinct changes in charge transport mechanism brought out by the interplay between surface chemistry and morphology of the electrospun scaffolds. The all-solid-state symmetric supercapacitor devices assembled with GNP@CC electrodes and PU/Ge, PU@Ge or Ge@PU polymeric membrane electrolyte of 1 M H3PO4 or EMIMBF4 are studied.Accordingly, the charge transport is protic and aprotic observed to switch from interfacial driven in the case of PU@Ge with H3PO4 to distinct phase separated ion transport channels in the case of PU/Ge with EMIMBF4. Thereby, a range of energy density (1.03–21.94 Wh kg−1), power density (0.049–99.97 kW kg−1) and scan rate operability (5–10,000 mV s−1) are demonstrated in such devices without any compromise on the cyclability. This study establishes rational design principles for tailoring the ion transport mechanism in a variety of matrices and thereby opens transformative possibilities for realizing high performance energy storage devices.

A Graphene Oxide–Thioamide Polymer Hybrid for High‐Performance Supercapacitor Electrodes

The controlled chemical functionalization of graphene oxide (GO) represents a powerful strategy to finely tune its physical and chemical properties toward applications in energy storage. Herein, an unprecedented approach for the GO modification with thioamide‐based polymers featuring numerous heteroatoms (S,N,O) is reported, which is instrumental for achieving superior electrochemical performance in symmetric supercapacitors. While the electrochemical investigations in aqueous electrolytes reveal specific capacitance of 221 F g−1 at 1 A g−1, the use of organic media allows the specific capacitance to be boosted up to 340 F g−1. Additionally, the increase of operating window yields energy densities as high as 94.4 Wh kg−1, thereby exceeding state‐of‐the‐art performances of GO‐based supercapacitors. Furthermore, the symmetric devices exhibit great robustness in both aqueous and organic electrolytes as evidenced by an excellent stability after 5000 working cycles (>98% in H2SO4 and >90% in TEABF4/ACN).

Investigation into the influence of interdigital parameters on electrochemical performance for in-plane supercapacitors via mathematical modeling and conformal mapping techniques

Herein, we propose a mathematical model and corresponding analytical transformation approach based on the conformal mapping technique and equivalent circuit conversion method to investigate the influence of interdigital parameters such as electrode length (Le), width (We), and spacing (De) on the electrochemical performance of in-plane supercapacitors (SCs) fabricated via CO2 laser processing on polyimide film and encapsulation with PVA/H3PO4 gel electrolyte. We conclude from the experiments that the small gap ensures a compact structure, a high electrode utilization rate, and a short anion/cation transport channel, while the large electrode area generates a sufficient electrostatic double-layer effect to improve areal capacitance. Furthermore, interdigital length and width are particularly sensitive to capacitve performance, implying that electrode area plays a critical role. Eventually, the optimal electrode parameters are 10 mm (Le), 1.5 mm (We), and 0.35 mm (De), delivering high areal capacitance (2.43 mF/cm2), relatively low resistance (≈46 Ω) and excellent areal energy density (225 μWh/cm2) and power density (3.65 mW/cm2). Because the experimental values are compatible with the simulation curves and the different percentages between them are controlled within 13 %, the mathematical model has theoretical significance for the design of interdigital electrodes.

Covalent functionalization of electrochemically exfoliated 1T-MoS2 nanosheets for high-performance supercapacitor electrode

Covalently functionalized 1T-MoS2 (Fc-1T-MoS2) nanosheets are synthesized by the chemical reaction between electrochemically exfoliated 1T-MoS2 nanosheets and iodobenzene. The NH2Ph ring functionality and 1T-MoS2 phase improves the electrochemical performance for supercapacitors by enhancing the charge density and electronic properties, which leads to fast charge transport and high charge storage capacity. The Fc-1T-MoS2 has a high specific capacitance of 501 F g−1 at a current density of 1 A g−1 with capacitance retention of 76.32% after 2000 cycles, which is 2.6 times of magnitude higher than that of bare 1T-MoS2 nanosheets. This study exposes the effect of functionalization of MoS2 nanosheets for supercapacitor applications.

Solvothermal synthesis of Al2Se3/rGO nanocomposites with excellent electrochemical performance in supercapacitor

As a supercapacitor material, transition metal selenide (TMS) can be synthesised in a cost-effective and simple manner. However, it suffers from low-rate capacities and poor cyclic stability due to their easy aggregation and structural instability during charge and discharge cycles. Herein, we report the synthesis of aluminum selenide (Al2Se3) nanorods over reduced graphene oxide (rGO) nanosheets as a novel material using the solvothermal method. The successful formation of Al2Se3/rGO nanocomposite was confirmed via XRD (X-ray diffraction), SEM (scanning electron microscopy), and XPS (X-ray photoelectric spectroscopy) and was also investigated for its optical characteristics and electrochemical performance. The optimised Al2Se3/rGO sample with 5 wt% and 10 wt% rGO exhibited high specific capacitances of 701.83 Fg−1 and 1138.1 Fg−1, respectively. Moreover, Al2Se3/10%rGO nanocomposite as a positive electrode achieves energy densities of 39.57 Wh/kg and power densities of 0.006 kW/kg at current densities 2.5 A/g along with stability up to 2000 cycles, suggesting it to be a significant technological candidate in the future. This work highlights an effective and feasible approach to engineer or construct TMS/rGO nanocomposites for charge storage applications.

Microwave-synthesized Bismuth oxide/Activated Carbon felt composite as electrode for ultra-high supercapacitors performance

Pseudocapacitance materials composite is a simple and practical approach for improving the performance of supercapacitors. In this study, Bi2O3@ACF nanocomposite was synthesized from the transition metal oxide Bi2O3 in an activated Carbon Felt (ACF) substrate by microwave irradiation. Electrochemical tests of the sample at 1000 W for 120 s show that the capacitance of the Bi2O3/ACF nanocomposite was 736 F g−1 at 1 A g−1. The electrochemical performance of flexible asymmetric supercapacitors with a voltage window of 1.7 V was evaluated. The energy density was calculated, and the obtained value was 28.6 Wh kg−1 at a power density of 0.9 kW kg−1. The device shows a capacitance retention of 67 % with a stability of approximately 5000 cycles. Bi2O3/ACF nanocomposite with excellent electrochemical properties may improve the performance of supercapacitors.

High-Performance Supercapacitors: A Comprehensive Review on Paradigm Shift of Conventional Energy Storage Devices

The enormous demand for energy due to rapid technological developments pushes mankind to the limits in the exploration of high-performance energy devices. Among the two major energy storage devices (capacitors and batteries), electrochemical capacitors (known as ‘Supercapacitors’) play a crucial role in the storage and supply of conserved energy from various sustainable sources. The high power density and the ultra-high cyclic stability are the attractive characteristics of supercapacitors. However, the low energy density is a major downside of them, which is also responsible for the extensive research in this field to help the charge storage capabilities thrive to their limits. Discoveries of electrical double-layer formation, pseudocapacitive and intercalation-type (battery-type) behaviors drastically improved the electrochemical performances of supercapacitors. The introduction of nanostructured active materials (carbon-/metal-/redox-active-polymer/metal-organic/covalent-organic framework-based electrode materials), electrolytes (conventional aqueous and unconventional systems) with superior electrochemical stability and unprecedented device architectures further boosted their charge storage characteristics. In addition, the detailed investigations of the various processes at the electrode–electrolyte interfaces enable us to reinforce the present techniques and the approaches toward high-performance and next-generation supercapacitors. In this review, the fundamental concepts of the supercapacitor device in terms of components, assembly, evaluation, charge storage mechanism, and advanced properties are comprehensively discussed with representative examples.

Alkali-Etched NiCoAl-LDH with Improved Electrochemical Performance for Asymmetric Supercapacitors

Hydrotalcite, first found in natural ores, has important applications in supercapacitors. NiCoAl-LDH, as a hydrotalcite-like compound with good crystallinity, is commonly synthesized by a hydrothermal method. Al3+ plays an important role in the crystallization of hydrotalcite and can provide stable trivalent cations, which is conducive to the formation of hydrotalcite. However, aluminum and its hydroxides are unstable in a strong alkaline electrolyte; therefore, a secondary alkali treatment is proposed in this work to produce cation vacancies. The hydrophilicity of the NiCoAl-OH surface with cation vacancy has been greatly improved, which is conducive to the wetting and infiltration of electrolyte in water-based supercapacitors. At the same time, cation vacancies generate a large number of defects as active sites for energy storage. As a result, the specific capacity of the NiCoAl-OH electrode after 10,000 cycles can be maintained at 94.1%, which is much better than the NiCoAl-LDH material of 74%.

Electrochemical performance of aqueous electrolytes in porous carbon derived cassava peel electrode material-based for sustainable symmetrical supercapacitor

Electrolytes have been generally recognized as one of the most important components in enhancing the electrochemical performance of supercapacitors. On the other hand, aqueous electrolytes are considered prime candidates for the development of the next generation of symmetric supercapacitors due to their low-cost, environmentally friendly, high ionic conductivity, fine ionic size, and high capacitance. Herein, the symmetrical supercapacitor of the sustainable porous carbon-based electrode material was confirmed through various aqueous electrolytes consisting of neutral, basic, and acidic Na2SO4, KOH, and H2SO4. Activated carbon is obtained from high potential biomass sources of cassava peel waste. Activated carbon synthesis was performed with a comprehensive approach in order to obtain abundant pore structure, high porosity, and improved wettability through a combination of high-temperature chemical and physical activation. in addition, the electrode material is designed to resemble a solid disc without the addition of a synthetic binder. The evaluation of the disc dimensions showed high porosity in the obtained activated carbon. Furthermore, the symmetrical supercapacitor of the optimized electrode material exhibit excellent specific capacitances of 112, 150, and 183 F g-1 at 1 mV s-1 in the electrolytes Na2SO4, KOH, and H2SO4, respectively. In addition, the highest rate capability of 70% was confirmed in the H2SO4 acid electrolyte. Moreover, their coulombic efficiency can be maintained around 89% with low equivalent series resistance 0.21-0.42 ?. Therefore, the activated carbon-based supercapacitor symmetric cell device from cassava peel shows high performance for developing high-performance supercapacitor applications with guaranteed stability in aqueous electrolytes.

Potential of MnO2‐based composite and numerous morphological for enhancing supercapacitors performance

AbstractThe development of materials and electrochemical energy storage (EES) technologies are currently taking the lead and showing excellent performance in the global effort to tackle the issues of sustainable energy supply. Supercapacitors have been widely studied among the EES technologies as they exhibit quick charging rates under high‐power conditions. Manganese dioxide (MnO2) has attracted renewed interest as a promising material due to its high theoretical capacitance and high energy density. However, the widespread application is immediately impacted by low conductivity. Hence, combining nanomaterials and various morphologies of MnO2 can improve the electrochemical performance of supercapacitors. This paper presents a review based on the composites of nanomaterials/MnO2 with various morphologies. Their mechanism and practical applications in supercapacitors are introduced in detail. Finally, the challenges and next steps in developing MnO2 electrode materials are proposed.

Enhanced electrochemical performance of CuCo2O4 nanowire arrays based solid-state symmetric supercapacitor by K3[Fe(CN)6] redox additive electrolyte

The redox additive in an aqueous gel electrolyte is reported as one of the efficient methods to improve the electrochemical supercapacitor performance. Here, we report the role of redox additive, potassium ferricyanide((K3[Fe(CN)6]), referred to as KFCN) for improving the electrochemical performance of binder-free, CuCo2O4 (CCO) nanowire arrays (NWs) based solid state symmetric supercapacitors (SSCs). The crystal structure and morphology of prepared CCO films are confirmed by X-ray diffraction (XRD) and field emission-transmission electron microscopy (FE-TEM). The elemental composition of CCO films is estimated as Cu0.5Co2.77O3.82 via energy-dispersive X-ray spectroscopy (EDS) analysis. Surprisingly, the areal capacitance (or energy density at 5 mAcm−2) is significantly improved from 0.58 F cm−2 (or 0.016 mWh cm−2) to 10.5 F cm−2 (or 0.296 mWh cm−2), respectively, after the addition of KFCN to aqueous KOH electrolyte, as compared to bare KOH. Furthermore, CCO exhibits decent cyclic stability with 90 % capacitance retention up to 5000 CV cycles at the scan rate of 100 mV s−1. Moreover, 2-terminal CCO NWs-based SSCs, employed with PVA-KOH-KFCN gel electrolyte, demonstrate a wider potential window of −0.9 to 0.9 V (1.8 V) with a 7-fold increase of energy density from 9.1 to 65 Wh kg−1, as compared with that of PVA-KOH gel electrolyte. As practical validation, the operation of Red-LED for 3 min is demonstrated with PVA-KOH-KFCN gel-based SSC, manifesting that adding redox substance in aqueous electrolytes is one of the promising strategies for portable and wearable energy storage systems.

Ca2.9La0.1Co4O9/graphene composite electrodes for improved electrochemical performance of cellulose-based supercapacitors

In this study, we report a highly flexible and biodegradable supercapacitor (SC) assembled with electrodes made of cellulose and graphene microplates. The cellulose was extracted from the palocote plant (tithonia tubaeformis), which is considered a weed in Mexico. To enhance the capacitance of the devices, Ca2.9La0.1Co4O9 (CaLaCo) particles with microplate morphology were added to the SC electrodes. The electrochemical characterization indicated that the SCs fabricated without CaLaCo particles exhibited a specific capacitance of 777.3 F/g (at 1 A/g) and an energy density of 108.1 Wh/kg. When the CaLaCo was introduced into the SC electrodes, the above parameters increased to 1320.3 F/g (at 1 A/g) and 182.3 Wh/kg, that is, the capacitive performance was enhanced by ≈ 70%. Also, the device made with the CaLaCo particles exhibited a high capacitance retention of 95.8% after 1500 continuous charging/discharging cycles. Some advantages in the devices made with CaLaCo in comparison with these fabricated without CaLaCo were: 1) longer discharge times and 2) low loss of capacitance (4.1%) at higher current densities (up to 10 A/g). On the other hand, redox peaks were observed in the cyclic voltammetry curves, suggesting the storage of charge by redox reactions. To find the redox centers responsible for the charge storage, optical absorbance, Raman and XPS measurements were carried out and we found that the oxygen vacancy defects and Co2+/Co3+ species were the main redox centers. Furthermore, EIS measurements showed that the series resistance (Rs) and charge transfer resistance (Rct) decreased by 28% and 80%, respectively, after the introduction of the CaLaCo oxide in the SC. The reduction of the Rs and Rct was relevant because it promoted the ion diffusion/storage in the electrodes, which in turn, increased the capacitance of the devices. Thus, the results of this report indicate that our biodegradable and flexible SC could be produced from sustainable materials and can be used as energy source for wearable/portable devices.

NiFeZnP Nanosheets with Enriched Phosphorus Vacancies for Supercapattery Electrodes

Designing and fabricating outstanding electrode materials via simple preparation routes are viable ways for improving the performance of electrochemical supercapacitors. We report on the synthesis of NiFeZn phosphide interconnected nanosheets with abundant phosphorus vacancies (Pv-NiFeZnP) via a facile reduction route at room temperature. The fabricated Pv-NiFeZnP was fully characterized using energy-dispersive spectroscopy, field emission scanning electron microscopy, electron paramagnetic resonance, and X-ray photoelectron spectroscopy techniques. Owing to the porous interconnected nanosheet structure and the superior stability enabled by the direct binder-free growth on Ni foam, the Pv-NiFeZnP electrode, with optimized phosphorus vacancy formation, exhibits a superb electrochemical performance of 631.8 mC/cm2 (equivalent to 1579.5 mF/cm2), which is significantly higher than those reported in the literature. Also, the Pv-NiFeZnP||activated carbon asymmetric device exhibits a very high Coulombic efficiency (∼100%) and excellent long-term stability (98.8% capacity retention after 7500 cycles). The fabricated device can deliver 122.1 μWh/cm2 energy density at a power density of 750 μW/cm2. The fabricated NiFeZnP electrode is therefore a promising candidate for supercapacitor applications.

An Intelligent Model for Supercapacitors with a Graphene-Based Fractal Electrode to Investigate the Cyclic Voltammetry

The aim of this study was to investigate the performance measurement of supercapacitors using the electrochemical properties of cyclic voltammetry (CV). The use of CV is crucial in evaluating the electrochemical performance of supercapacitors and determining the surface area of the catalyst with regard to the fractal properties of the electrode. The study specifically focused on the CV behavior of a supercapacitor formed by a cobalt-doped ceria/reduced graphene oxide (Co-CeO2/rGO) fractal nanocomposite, and its assessment was conducted using a machine learning (ML) model with the enhanced XGBoost. The model was trained using an experimental open-source dataset. The results showed that the proposed XGBoost model had a superior ability to predict the CV behavior of the supercapacitor, with nearly perfect results for the MAE, RMSE, and R-squared metrics, which are effective at evaluating the performance of regression models. With the successful design of the proposed intelligent prediction model, the study is expected to provide valuable insights into forming novel nanocomposite forms with high accuracy and minimal need for experiments.

Road Map for In Situ Grown Binder-Free MOFs and Their Derivatives as Freestanding Electrodes for Supercapacitors.

Among several electrocatalysts for energy storage purposes including supercapacitors, metal-organic frameworks (MOFs), and their derivatives have spurred wide spread interest owing to their structural merits, multifariousness with tailor-made functionalities and tunable pore sizes. The electrochemical performance of supercapacitors can be further enhanced using in situ grown MOFs and their derivatives, eliminating the role of insulating binders whose "dead mass" contribution hampers the device capability otherwise. The expulsion of binders not only ensures better adhesion of catalyst material with the current collector but also facilitates the transport of electron and electrolyte ions and remedy cycle performance deterioration with better chemical stability. This review systematically summarizes different kinds of metal-ligand combinations for in situ grown MOFs and derivatives, preparation techniques, modification strategies, properties, and charge transport mechanisms as freestanding electrode materials in determining the performance of supercapacitors. In the end, the review also highlights potential promises, challenges, and state-of-the-art advancement in the rational design of electrodes to overcome the bottlenecks and to improve the capability of MOFs in energy storage applications.

Gel combustion synthesized NiMoO4 anchored polymer nanocomposites as a flexible electrode material for solid state asymmetric supercapacitors

Recent research has focused on the search for new electrode materials to improve the specific capacitance of supercapacitors. Conductive polymers and metal oxides have been extensively tested as electrode materials for supercapacitors. Incorporating both conductive polymers and metal oxides into a composite provides excellent results for the electrochemical performance of supercapacitors. In this present work, we have fabricated the nanoscale α-NiMoO4 particles that enwrapped on electronically conducting polymer nanocomposites (PNCs) based on Polyvinyl alcohol (PVA)/Poly(vinyl) pyrrolidone (PVP) for supercapacitor applications. The different concentrations of PVA/PVP with α-NiMoO4 loaded polymer nanocomposites were developed by using a solution casting method. All the polymer nanocomposites have been subjected to Scanning Electron Microscopy (SEM), Fourier Transforms Infrared (FTIR), X-ray diffraction (XRD), and electrochemical studies. The prepared PNCs surface morphology has been acquired as a non-uniform rod-like structure. The electrochemical performances of the prepared PNCs have been investigated and the resultant value of the maximum specific capacitance is 15.56 F g−1 for 1 wt % of α-NiMoO4 nanoparticles(NPs) loaded polymer blended electrode at a scan rate of 5 mVs−1. The prepared PNCs exhibit 97.12% of columbic efficiency studied by using two electrode systems at room temperature in an aqueous electrolyte solution of 3 M KOH. From these investigation, it has been revealed that the PVA/PVP/α-NiMoO4 composites could be portable and flexible electrodes for energy storage applications.

Defect and interface engineering of MXene-tagged N,F-doped carbon-CoSe2 heterostructure for superior hydrogen evolution reactions and supercapacitors

Defect and interface engineering on heterostructured electrode materials is an effective approach to improve the electrochemical performance of supercapacitors and water-splitting. Herein, we have prepared MXene nanosheets-tagged hetero atom-doped graphitic carbons wrapped CoSe2 (MXe-F,N-gCW-CoSe2) polyhedral heterostructure electrode material, and further investigated kinetic and thermodynamic factors that affect on defect and interface engineering to facilitate efficient electron and ionic path and promote the electrochemical active sites. The composites exhibit excellent hydrogen evolution reaction (HER) performances of the Tafel slope of 84.2 mV dec−1 and 94.5 mV dec−1 in 1 M KOH and 0.5 M H2SO4, respectively. It also shows a high specific capacity of 403.4C g−1 at 1 A g−1 and the thus-assembled MXe-F,N-gCW-CoSe2//AC hybrid supercapacitor revealed an energy density of 44.2 Wh kg−1 at a power density of 851.3 W kg−1 with superior stability of ∼94% after 10,000 cycles.

Recent Progress and Future Directions of Biomass-Derived Hierarchical Porous Carbon: Designing, Preparation, and Supercapacitor Applications

In the past decades, fossil energy depletion, environmental pollution, and greenhouse gas emissions have resulted in serious health threats and ecological imbalances, which prompt researchers to explore green and sustainable supercapacitor energy storage and conversion systems. Biomass is a promising renewable energy source to use for biomass porous carbon for supercapacitor devices because it is renewable and has abundant reserves, a low price, and low pollution carbon energy. To date, although some reports have screened different biomass precursors, carbonization methods, and activation strategies and mechanisms, a comprehensive evaluation and critical review of the correlation among biomass porous carbon properties, including pore structure and surface chemistry, and electrochemical energy storage performances of supercapacitors are absent from a multidisciplinary assessment perspective. Therefore, in this review, we summarize recent advances in the biomass porous carbon synthesis process focusing on different carbonization and activation strategies, point out the scope of applicability and advantages/disadvantages of these methods in supercapacitor applications, and reveal the reaction mechanisms and limitations for commercial production. Then, the relationships among biomass porous carbon properties, including hierarchical porous structure, surface chemistry, specific surface area, and electrochemical performances of supercapacitors are reviewed in detail, which enables researchers to prepare and design advanced materials in a more rational way and facilitates them to explore more cutting-edge energy storage materials. Finally, two effective techniques including heteroatom doping and composite material construction are reviewed to address the general problem of low supercapacitor energy density. This review demonstrates the great potential of biomass porous carbon with superior properties, provides advanced tailoring and design viewpoints for the application fields of high-performance supercapacitors, and is expected to inspire new exploration and boost the practical commercial applications of biomass-derived hierarchical porous carbon material in more energy storage and conversion fields.

Thermally oxidized activated carbon with high specific surface area to boost electrochemical performance for supercapacitor

Thermally oxidized activated carbon (TOAC), acidified activated carbon (AAC) and thermally deoxygenized AC (TAC) were fabricated. The oxygen content of TOAC increased from 10.5 wt% for pristine AC to 14.8 wt%. The specific surface area of TOAC (3260.4 m2 g−1) was much higher than that of the AAC (2318.8 m2 g−1) and TAC (2811.8 m2 g−1). The TOAC obtained a high capacitance of 420.0 F g−1 at 1.0 A g−1 in the voltage range of −1.0 V ∼ 0 V, which was significantly higher than AC (287.0 F g−1), AAC (266.0 F g−1) and TAC (208.0 F g−1). The results indicated that the anchoring oxygen and large specific surface area had a synergistic effect on the capacitance performance. The plentiful oxygen could enhance the wettability between electrode and electrolyte. And the large specific surface area could provide plenty of positions for ions adsorption and accelerate the ionic diffusion and transport.