Cathode For Supercapacitors Research Articles

Hybrid Particle Size Template Method for Controllable Synthesis of Nitrogen-doped Multilevel Porous Carbon as High-rate Zn-ion Hybrid Supercapacitor Cathode Materials.

Achieving high rate performance without compromising energy density has always been a critical objective for zinc-ion hybrid supercapacitors (ZHSCs). The pore structure and surface properties of carbon cathode materials play a crucial role. We propose utilizing a hybrid particle size (20 and 40 nm) magnesium oxide templates to regulate the pore structure of nitrogen-doped porous carbon derived from the soybean isolate. The multilevel pore structure enhanced ion transport efficiency while also improving the utilization of micropores. Nitrogen doping and oxygen-containing functional groups enhanced the wettability of carbon materials with aqueous electrolytes and facilitated the chemisorption of Zn2+ on the carbon material surface. The nitrogen-doped multilevel porous carbon material (HT-NMPC-1/1) prepared with a 1:1 mass ratio of the two templates exhibited a specific capacity of 146.65 mAh g-1 at 0.2 A g-1. Moreover, the Swagelok cells assembled with HT-NMPC-1/1 and Zn foil achieved a high energy density of 121.5 W h kg-1, high power output of 166 W kg-1, and 93.09% capacity retention after 8000 cycles at 2 A g-1. Therefore, HT-NMPC-1/1 is a highly promising candidate for ZHSCs cathode materials. Furthermore, the novel pore regulation strategy and straightforward preparation method offer valuable reference points for other porous carbon-based functional materials.

Microwave-assisted vanadium interpolated cobalt-MOF cathode assembled 3 V high performing asymmetric supercapacitor with ionic liquid gel polymer electrolyte

To ameliorate energy storage and conversion, metal synergy, and structural stability, bimetal-assembled metal–organic frameworks (MOFs) are delved into. Augmented surface area, pseudo capacitance, and the ability to alter the MOF edifice of layered oxide have drawn interest in MOF-based oxide layered structures. Simple microwave and hydrothermal techniques use dimethyl formamide and water as solvents and annealing methods to generate the bimetallic organic framework’s Co3V2O8 and Co3VO4 cathode material. Those customized shapes boost redox sites and reduce ion electron distance. Due to cobalt’s faradaic process and vanadium’s highly layered attributes, supercapacitor electrode response is significant. Co3V2O8 has 1391F/g specific capacitance at 2 mV/s scan rate and 1309F/g at 4 mA/cm2 implemented current value. After 10,000 cycles, the cathode material depicts 89 % capacity retention and 98 % coulombic efficiency. Biowaste-derived activated carbon is combined with a Co3V2O8 cathode for asymmetric supercapacitor storage. That device works on 3 V windows with ionic liquid gel polymer electrolyte. With a maximum specific energy of 329.3 Wh/kg and specific power of 15250 W/kg, the achieved galvanometric capacitance is 263.5F/g and 220 mAh/g at the 9 mA/cm2 current and showed 88.5 % potential stability after 10,000 cycles. These findings corroborate its use as a supercapacitor cathode.

Construction of MOF-derived Ni-Co-Se/MXene heterostructured composite as hybrid supercapacitor cathode

Construction of MOF-derived Ni-Co-Se/MXene heterostructured composite as hybrid supercapacitor cathode

Preparation of Flower-Like Layered Double Hydroxides Supercapacitor Cathode Based on Biomineralization Strategy

Preparation of Flower-Like Layered Double Hydroxides Supercapacitor Cathode Based on Biomineralization Strategy

Heterostructure Engineering of Biphase‐Coupled Ternary Transition Metal Phosphoselenide by Topological Transformation Enabling High Performance for Supercapacitors

AbstractThe exploration of promising electrode materials with structural stability and rapid interfacial reaction kinetics is highly desirable for supercapacitors toward large‐scale applications. Herein, the synthesis of biphase‐coupled CoPSe/NiP0.24Se1.76 with multiple in‐plane heterointerfaces using the in situ topological transformation approach is presented. As a novel ternary metal phosphoselenide (TMPSe) for supercapacitor cathode that is fabricated by synchronous phosphoselenization strategy, it realizes a superior lifespan with cycling compared to conventional transition metal selenides. The depleted anti‐bonding eg* orbitals of transition metal ions (Co/Ni) in the CoPSe/NiP0.24Se1.76, as proved by preliminary theoretical calculations, strengthens the chemical bonding between Co/Ni and coordinating atoms, thereby enhancing the chemical stability. Simultaneously, the CoPSe/NiP0.24Se1.76 in‐plane multi‐heterostructures can not only alleviate the volume change during the charge–discharge process but also expose more active sites, promoting the adsorption of OH− ions, which is conducive to the rapid redox reaction kinetics of the CoPSe/NiP0.24Se1.76, and consequently, it delivers a remarkable reversible capacity and excellent long‐term cycle stability with 97.7% initial capacitance retention over 16 000 cycles. Moreover, the asymmetric supercapacitors with this cathode demonstrate outstanding rate capability and high energy density. This strategy of constructing biphase‐coupled CoPSe/NiP0.24Se1.76 by topological transformation is of great potential application for the high‐performance electrode material.

Ultrasound-assisted synthesis of Co(OH)2 nanoflowers and nanosheets as battery-type cathode for high-performance supercapacitors

The depletion of traditional energy resources and the escalating environmental concerns have compelled researchers to pursue green energies, among which the supercapacitors possess a crucial function in electrochemical energy storage systems. In this study, the Co(OH)2 nanoflowers and Co(OH)2 nanosheets have been respectively synthesized utilizing a safe and facile ultrasound-assisted method in the solvent with different pH values, and the product is denoted as Co(OH)2-7.5 and Co(OH)2-9.5, accordingly. The Co(OH)2-7.5 exhibited a specific surface area of 188.3 m2 g, significantly greater than that of Co(OH)2-9.5. Additionally, these Co(OH)2 electrode materials showed battery-type electrochemical response, and the Co(OH)2-7.5 presented an impressive specific capacity of 371.6 C g−1. When integrated into a hybrid supercapacitor (HSC) device with activated carbon (AC) as anode, the device exhibited an exceptional cycling stability after 10000 cycles at 10 A g−1. Furthermore, the Co(OH)2-7.5//AC HSC delivered an impressive energy density (De) of 30.2 W h kg−1 at the power density (Dp) of 888.6 W kg−1, and this De surpassed the 26.4 W h kg−1 of Co(OH)2-9.5//AC HSC. The Co(OH)2 in this work shows good application potential in the field of supercapacitors. The straightforward and efficient synthesis technique can be further applied to the synthesis of many other transition metal hydroxides with remarkable electrochemical properties.

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.

Synergistic effects in CuO/SnO2/Ti3C2Tx nanohybrids: Unveiling their potential as supercapacitor cathode material

In the field of materials science, a synergistic effect occurs when the combined physical and chemical properties of a composite material show significant improvement compared to the properties of its individual components. In this study, we synthesized a novel nanosheet-like structure composed of copper oxide (CuO) and tin oxide (SnO2) dispersed on MXene (Ti3C2Tx) sheets using an ultrasonicated coprecipitation method, and then we explored its synergistic effects. The CuO/SnO2/MXene nanohybrids were characterized through SEM, HRTEM, XRD, XPS, and BET analysis, confirming successful synthesis and evident synergy between MXene and CuO/SnO2. The electrochemical behaviour of the nanohybrid structure was investigated using different electrochemical techniques. CuO/SnO2/MXene revealed a high capacitance of 683.5 Fg-1 at 1 Ag-1 in a 2 M H2SO4 electrolyte, with 85 % cycling performance after 10,000 cycles. Notably, this performance surpassed that of MXene-Ti3C2Tx and CuO/SnO2 separately, which achieved only 102.8 and 378.2 Fg-1 capacitance with 60 % and 76 % cycling stability, respectively. These incredible results are attributed to CuO/SnO2/MXene nanohybrids' synergistic effects, whereby enhance the surface area, electrical conductivity, and availability of active sites and enhanced electrochemical performance. This research offers a promising solution for advancing supercapacitor electrode materials through the creation of a novel nanosheet structure that leverages synergistic effects.

Facile synthesis of cryogenically controlled cobalt-nickel-based Prussian blue analogues for high-performance symmetric supercapacitors

Cobalt hexacyanoferrate (CoHCF) with high energy density as a potentially useful electrode for energy storage systems still suffers from inferior rate capability and low cycling performance due to high-spin nitrogen-coordinated Co ions. While nickel hexacyanoferrate (NiHCF) with low energy density can exhibit great cycling stability due to the electrochemical inertness of Ni. Herein, we have developed a series of cobalt nickel hexacyanoferrate (CoNiHCF) via a facile cryogenically controlled co-precipitation method. We explored the Co/Ni molar ratio and synthesis temperature on the effects of the specific capacitance in detail. As supercapacitor cathode, the Co0.7Ni0.3HCF with the Co/Ni molar ratio of 0.7:0.3 synthesized at 0 °C can exhibit a high specific capacitance of 406 F g−1 at 1 A·g−1 with capacitance retention of 81.89 % after 5000 cycles. The exceptional electrochemical performance is ascribed to the upgraded conductivity resulting from the coexistence of bimetallic components, the low particle size caused by the moderate introduction of Ni, the low interstitial water content, and the synergistic effect between Co and Ni. Moreover, the symmetric supercapacitor (SSC) of Co0.7Ni0.3HCF//Co0.7Ni0.3HCF can provide a high energy density of 72.96 W h kg−1 and 40.96 W h kg−1 at specific powers of 2876 W kg−1 and 28,577 W kg−1, respectively with a capacitance retention of 74.83 % after 4000 cycles.

Elevating energy storage performance of bismuth antimonate coupled with MXene and graphitic nanofibers in advanced supercapacitors

Improving the electrochemical performance of metal oxide-based materials for energy storage devices often involves employing key strategies, including the deliberate modification of composition through composite formation and the application of structural engineering techniques. Herein, we have synthesized bismuth antimonate (BiSbO4) and ternary structure is constructed by integrating Graphitic Nanofiber (GNF) and MXene (MX) via a facile hydrothermal method. The synergistic effect of the well-defined structure, coupled with the excellent electrical conductivity facilitated by the MXene and GNF networks, significantly contributes to the outstanding energy and power density. The unblocked ion and electron channels within its hierarchical structure enhances the material's performance as a battery-type cathode for supercapacitors. This work reports a notable specific capacitance of 819 F g−1 at 1 A g−1 and an impressive durability, with 94% capacity retention after 5000 charge/discharge cycles in a three-electrode system. Furthermore, an asymmetric supercapacitor device BSO–GF–MX‖AC is fabricated with activated carbon as negative electrode, which delivered superior energy density 46 Wh kg−1 at power density 750 W kg−1 and retains 90.6% of initial capacitance. This study provides a promising strategy for fabricating ternary composite-based electrodes, offering a pathway to assemble high-performance and cost-effective energy storage devices.

Electrochemical and scanning transmission X-ray microscopy studies of MnO2 and Mn3O4 for supercapacitor cathodes: Influence of fabrication method and electrochemical activation on charge storage

This investigation is motivated by increasing interest in Mn3O4 as a promising alternative to MnO2 for supercapacitors with high active mass and the need for better understanding of charging and electrode activation mechanisms. High energy ball milling (HEBM) of chemically precipitated MnO2 and Mn3O4 in the presence of quercetin resulted in significant capacitance increase. The use of Mn2+ salts for Mn3O4 synthesis facilitated the application of quercetin as a new chelating capping agent for synthesis of Mn3O4, which showed higher capacitance, compared to HEBM Mn3O4. The capacitance of Mn3O4 prepared using quercetin was 6.0F cm−2 (149.50 F g−1) for cyclic voltammetry at 2 mVs−1 and 8.03 F cm−2 (200.93 F g−1) for chronopotentiometry at 3 mA cm−2, which is on-par with the capacitance of MnO2. The time-consuming activation procedure, which limits Mn3O4 applications, was significantly accelerated for HEBM Mn3O4 and practically eliminated for Mn3O4 prepared using quercetin as a capping agent. Soft X-ray scanning transmission X-ray microscopy (STXM), an advanced synchrotron based analytical microscopy, was used at the O 1s and Mn 2p edges to identify and quantitatively map the Mn oxidation states present in Mn3O4 materials. Variable and fixed sweep rate electrochemical cycling procedures were used for the analysis of oxidation state of Mn and charging mechanism using STXM analysis coupled with electrochemical testing. The combination of STXM and electrochemistry provided valuable insights into the activation kinetics and charging mechanism. The STXM results showed that the tested materials contained mixtures of Mn2+, Mn3+ and Mn4+ oxides. A small amount of MnO phase in the tested samples indicated partial reduction. The higher content of MnO2 phase in the tested Mn3O4 prepared using quercetin as a capping agent, compared to HEBM Mn3O4, correlated with higher capacitance and the ability to eliminate the activation procedure.

Hierarchical high K content birnessite MnO2 nanosheet arrays as high capacity cathode for asymmetric supercapacitor with broaden potential window of 2.6 V

High specific capacitance and energy density for energy storage devices are dependent on the types of electrodes selection and operational working potential windows. Birnessite MnO2 is reported as the astounding material to show strong electrochemical performances due to it's widen inter-planar spacing, capable to accommodate the alkaline ions for the better outcomes. Herein this article, high K content Birnessite MnO2 nanosheet arrays at carbon cloth substrate (K0.46MnO2 NSAs@CC) are successfully fabricated to optimize its structural, morphological and electrochemical performances as cathode for supercapacitors (SCs). K0.46MnO2 NSAs@CC is operated at broaden potential window from 0 to 1.3 V to achieve excellent specific capacitance of ∼375 F g−1. Reported broaden potential window provides the opportunity for the construction of aqueous asymmetric supercapacitors (ASC) to operate above 2.0 V. For the construction of efficient ASC, Bi2S3 nanoflakes interconnected nanosheets at carbon cloth (Bi2S3 NFNS@CC) are synthesized as anode capable to operate at negative (−1.3 to 0 V) potential window. The 2.6 V ASC is constructed by K0.46MnO2 NSAs@CC as cathode and Bi2S3 NFNS@CC as an anode (K0.46MnO2 NSAs@CC//Bi2S3 NFNS@CC). K0.46MnO2 NSAs@CC//Bi2S3 NFNS@CC as ASC is presenting excellent energy density of ∼72 Wh kg−1 on top of outstanding cycle performance and rate capability compatible with the earlier reported MnO2-based ASCs. This work is elaborating the new guidelines for novel electrode materials scheme and possibilities to achieve broaden potential windows capable to be utilized in practical devices.

Recovery of cobalt based materials from spent Li-ion batteries and their use as electrode material for supercapacitor

In this work, Co(OH)2 and Co3O4 were obtained to be used in coin cell-type supercapacitors from a lithium-ion battery whose cathode material is LiCoO2 for the first time in the literature. Firstly, LiCoO2 cathode material was taken from the dismantled li-ion battery, and leaching of cathode material was carried out using HNO3 and H2O2. Leaching was performed with a maximum yield of approximately 94 %. Then Co(OH)2 was precipitated in a basic medium by using a NaOH solution. Thermal analysis was applied to the produced Co(OH)2 to determine the behavior for conversion from Co(OH)2 to Co3O4. Two different Co3O4 powders were obtained as Co3O4-450 and Co3O4-1000 by calcination of precipitated Co(OH)2 at 450 and 1000 °C. Produced powders were characterized by lots of characterization methods such as XRD, Raman, SEM and BET. Three different electrode material for the coin cell type asymmetric supercapacitor cathode was made from produced powders by mixing with carbon black and PVDF. GCD, CV and EIS measurements were used evaluate the electrochemical properties of the supercapacitors. The maximum areal capacitance value of 98 mF.cm−2 was obtained at 10 mV/s scan rate in Co3O4-450 based supercapacitor.

A multi-interface bimetallic sulfoselenide–selenite heterojunction as a battery-type cathode for high-performance supercapacitors

A bimetallic sulfoselenide–selenite heterojunction of (Ni,Co)(Se,S)2/(Ni,Co)SeO3 was prepared from LDH-based templates as high-capacity battery-type materials for hybrid supercapacitors.

Facile synthesis and electrochemical analysis of TiN-based ZnO nanoparticles as promising cathode materials for asymmetric supercapacitors.

In today's energy landscape, the rise of energy crises spurred by rapid industrial expansion demands the development of advanced energy storage systems, especially those leveraging renewable sources independently. Pseudocapacitors, renowned for their high specific capacitance (C s), offer a promising solution. Among them, transition metal nitride-based oxides stand out because of their remarkable conductivity and storage capacity, making them ideal candidates for supercapacitor (SC) cathode materials. In a recent study, we employed a wet-chemical method to synthesize a TiN-ZnO composite, showing potential as an electrode material for supercapacitor systems. The resulting composite exhibited promising crystallinity, indicating its suitability for electrode applications. Impressively, the TiN-ZnO electrode demonstrated a specific capacitance (C s) of 469 F g-1 during electrochemical testing. Additionally, it showcased a high energy density (E d) of 19.83 W h kg-1 and a power density (P d) of 6298.2 W kg-1. Moreover, it displayed exceptional cycling stability, retaining 95% of its performance over 7500 cycles. With superior electrochemical properties compared to pure materials, the fabricated TiN-ZnO electrode holds significant promise for supercapacitors and other energy-related technologies. This advancement presents a compelling solution to the urgent need for efficient and sustainable energy storage in the modern era.

Tuning nitrogen species in 3D porous carbon via boron doping for boosted Zn-ion storage capability

A strategy for the conversion of graphitic-N to edge-N in a carbon matrix by the additional incorporation of boron element for zinc-ion hybrid supercapacitor cathodes.

Microwave Construction of NiSb/NiTe Composites on Ni-Foam for High-Performance Supercapacitors.

In this paper, NiSb/NiTe/Ni composites were smoothly developed via the microwave method for supercapacitors. The synthesis of NiSb/NiTe crystals was revealed by X-ray photoelectron spectroscopy and X-ray diffraction. The analytic results of scanning electron microscopy and energy dispersive spectroscopy uncover the microscopic morphology as well as the constituent elements of the composites. Self-supported NiSb/NiTe is a supercapacitor cathode that combines high capacitance with excellent cycling stability. The obtained composite electrode displayed remarkable electrochemical properties, presenting a special capacitance of 1870 F g-1 (1 A g-1) and 81.5% of the original capacity through 30,000 times (10 A g-1) of the charging/discharging process. Further, an asymmetric supercapacitor was prepared employing NiSb/NiTe as a cathode and activated carbon as an anode. NiSb/NiTe//AC exhibited a high energy density of 224.6 uW h cm-2 with a power density of 750 μW cm-2 and provided a favorable cycling stability of 83% after 10,000 cycles.

Tuning the Composition, Crystal Structure and Morphology of Manganese(III/IV) Oxide for High-Power Storage Applications

If inherently intermittent renewable energy technologies are to offer a practical alternative to conventional heat engines, it is critically important that efficient, cost-effective and sustainable energy storage solutions are developed to decouple supply and demand profiles. A promising strategy is to pair the competitive energy densities of batteries with the superior cycling lifetimes and power densities of supercapacitors,[1] employing an appropriate maximum power point tracking (MPPT) system to optimise energy exchange between these complementary devices.[2] Mixed-valence manganese(III/IV) oxides (MnOz, where z ranges between 1.5 and 2.0) have emerged as foremost candidates for the electroactive material in supercapacitor cathodes due to their low toxicity, minimal cost,[3] ready availability (manganese appears at an average concentration of ca. 1,000 ppm in the Earth’s crust[4]), wide electrochemical stability window (ca. 1.0 V in aqueous electrolytes[5]), and high maximum theoretical specific capacitance (ca. 1,370 F g-1, based on the reduction of Mn4+ ions by a single electron[6]). Charge storage in MnOz is predominantly mediated by the pseudocapacitive intercalation of cations from the surrounding electrolyte in each discharge phase, followed by the release of these guest ions during charging.Of the various crystallographic phases of MnOz, cryptomelane (α-MnOz) and birnessite (δ-MnOz) polymorphs are deemed two of the most promising candidates for storage applications because they possess characteristically wide channels for intercalation/de-intercalation:[8,9] α-MnOz consists of ca. 4.6 Å diameter one-dimensional tunnels enclosed between corner-sharing MnO6 octahedra, whereas δ-MnOz comprises two-dimensional layers of MnO6 octahedra separated by ca. 7.0 Å. Herein, a scalable, low-cost synthesis procedure is discussed that enables the production of highly pseudocapacitive birnessite and cryptomelane electrodes with tuneable material characteristics, including particle morphology, crystallographic structure, average Mn oxidation state, and the level of pre-intercalation by Na+ and K+ ions.[10] In addition to comparing the electrochemical properties of these NaxKyMnOz products in aqueous conditions, their application within an asymmetric supercapacitor is showcased: by optimising the relative masses of a NaxKyMnOz cathode and activated carbon anode in a 100 cm2 aqueous full-cell configuration, discharge capacitances in the range 10-30 F g-1 can be achieved over a voltage span of 1.8 V at current densities as high as 10 A g-1, with Coulombic efficiency exceeding 80% up to ca. 20 A g-1. With these competitive performance characteristics, the developed NaxKyMnOz materials are a promising option for high-power supercapacitor cathodes, helping to pave the way towards more efficient and sustainable energy storage.

High-efficiency activated phosphorus-doped Ni2S3/Co3S4/ZnS nanowire/nanosheet arrays for energy storage of supercapacitors

Transition metal sulfides (TMS) have been considered as a promising group of electrode materials for supercapacitors as a result of their strong redox activity, but high volumetric strain of the materials during electrochemical reactions causes rapid structural collapse and severe capacity loss. Herein, we have synthesized phosphorus-doped (P-doped) Ni2S3/Co3S4/ZnS battery-type nanowire/nanosheet arrays as an advanced cathode for supercapacitor through a two-step process of hydrothermal and annealing treatments. The material has a one-dimensional nanowire/two-dimensional nanosheet-like coexisting microscopic morphology, which facilitates the exposure of abundant active centers and promotes the transport and migration of ions in the electrolyte, while the doping of P significantly enhances the conductivity of the electrode material. Simultaneously, the element phosphorus with similar atomic radii and electronegativity to sulfur may act as electron donors to regulate the electron distribution, thus providing more effective electrochemically active sites. In gratitude to the synergistic effect of microstructure optimization and electronic structure regulation induced by the doing of P, the P-Ni2S3/Co3S4/ZnS nanoarrays provide a superior capacity of 2716 F g−1 at 1 A/g, while the assembled P-Ni2S3/Co3S4/ZnS//AC asymmetric supercapacitor exhibits a high energy density of 48.2 Wh kg−1 at a power density of 800 W kg−1 with the capacity retention of 89 % after 9000 cycles. This work reveals a possible method for developing high-performance transition metal sulfide-based battery-like electrode materials for supercapacitors through microstructure optimization and electronic structure regulation.

Low‐cost porous carbon materials prepared from peanut red peels for novel zinc‐ion hybrid capacitors

AbstractZinc‐ion hybrid capacitors combine the advantages of supercapacitors and batteries and are a promising electrochemical energy storage device. In order to meet the demand for materials with higher energy density and longer cycle time, there is an urgent need to find a zinc‐ion supercapacitor cathode material with lower cost and better electrochemical performance. In this experiment, low‐cost agricultural peanut red skin waste was converted into biomass‐derived carbon material (PSR‐X) with high specific surface area, larger pore volume, and more homogeneous pore size distribution through carbonisation and KOH activation. Due to the interaction of these properties, PSR‐X as the cathode material has higher specific capacity and better multiplicity performance than the zinc‐ion capacitor prepared from the initial carbonised PSR as the cathode material. In addition, the PSR‐4‐based zinc‐ion capacitor has an excellent specific capacity of 86 mAh g−1 at a current density of 0.1 A g−1, a high capacity retention of 55 % even at a high current density of 30 A g−1, and a high energy density of 66.16 Wh kg−1 at a power density of 218.1 W kg−1. What is more gratifying is that the capacitor exhibits an ultra‐long cycle life, with a high capacity retention rate of 85 % after 8,000 charge/discharge cycles at a current density of 1 A g−1.