Supercapacitor Energy Storage Research Articles

A seamless start-up for a hybrid uninterruptible power supply based on a diesel generator and supercapacitor energy storage

A seamless start-up for a hybrid uninterruptible power supply based on a diesel generator and supercapacitor energy storage

Efficient synthesis of main chain thermosetting polybenzoxazine resin containing tert-butylcyclohexanone and diphenylmethane units for supercapacitor energy storage

Ring-opening polymerization (ROP) can be utilized to synthesize polybenzoxazine (PBZ) precursors from their respective benzoxazine monomers, resulting in thermosetting phenolic resins. In this study, we synthesized DADCA-DADPM BZ using 4-(tert-butyl)-2,6-bis((E)-4-hydroxybenzalidene)cyclohexan-1-one (DADCA) and 4,4′-diamino-diphenylmethane (DADPM) with paraformaldehyde. The resulting DADCA-DADPM BZ and poly(DADCA-DADPM BZ)_X materials were obtained after thermal curing polymerization at temperatures ranging from 110 to 250 °C were employed as electroactive materials in electrode preparation for supercapacitors (SCs). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) revealed a thermal curing temperature of 230 °C, a char yield of 35 wt%, and a decomposition temperature (Td10) of 288 °C. The electroactive material DADCA-DADPM BZ and poly(DADCA-DADPM BZ)_X materials were evaluated for their suitability in SCs, showing a specific capacitance ranging from 84.6 to 166.6 F g−1, depending on the thermal curing temperature (110–250 °C). Notably, the poly(DADCA-DADPM BZ)_250 retained 84 % of its efficiency after 5000 consecutive cycles at 10 A g−1, highlighting its potential for recyclability.

Role of samarium doping in ZnSe electrode material with increased electrocapacitive properties for supercapacitor energy storage applications

Researchers have recently paid great attention to different transition metals-basedsupercapacitor electrode materials, which haveincreased interest due to their excellent energy storage applications. In this regard, electrodes based on samarium-doped materials have shown impressive promise for higher-performingsupercapacitors and energy-storing devices in many industries. In the present work, Sm-doped ZnSe electrode material was fabricated by using a simple hydrothermal method and then characterized structurally and morphologically by various physical characterizations. When prepared Sm-doped ZnSewasevaluated in three electrode configurations,then displayedan impressive specific capacitance(923.43F/g), high energy density (45.43 Wh/kg) along with power density (297.6 W/kg)at 1 A/g,higher as compared with ZnSe. According to EIS characterization small charge transfer resistance (0.10 Ω) of the doping material was calculated while chronoamperometry data showed that the fabricated electrode exhibited higher stability of 30 h. This work shows that doping of Smto ZnSeenhances energy storage efficiency and suggests great energy storage abilities in supercapacitors and other energy storage devices.

Redox-active a pyrene-4,5,9,10-tetraone and thienyltriazine-based conjugated microporous polymers for boosting faradaic supercapacitor energy storage

Conventional supercapacitor electrodes typically suffer from drawbacks such as low energy density, short cycle life, and poor conductivity. In contrast, conjugated microporous polymers (CMPs) present a more advantageous option, providing higher surface area, greater cycle stability, and enhanced electrical properties. Utilizing pyrene-4,5,9,10-tetraone (PyTE) as a key redox-active component, we successfully prepare pyrene-4,5,9,10-tetraone-thiophene polymer (PyTE-Th Polymer) and Thienyltriazine-pyrene-4,5,9,10-tetraone conjugated microporous polymer (TTh-Ph-PyTE CMP). This particular set of materials has been tailored for supercapacitor applications, employing a nitrogen-rich triazine, conductive thiophene (Th), and redox-active pyrene-4,5,9,10-tetraone (PyTE), a creation through simple Suzuki coupling conditions. PyTE-Th Polymer and TTh-Ph-PyTE CMP exhibit comparable BET surface areas and demonstrate good thermal stability, with char yields exceeding 62 wt% for each material. Electrochemical measurements reveal that TTh-Ph-PyTE CMP, featuring a triazine group with abundant heteroatoms, exhibited exceptional cycle stability of 90 % after 5000 cycles at 10 A g−1 and a specific capacitance of 1041 F g−1 (1 A g−1). Notably, TTh-Ph-PyTE CMP portrays the maximum specific capacitance at 1 A g−1 compared to PyTE-Th polymer (486 F g−1) and other porous materials, suggesting a synergistic effect of redox-active units and abundant heteroatoms.

A Q‐Learning and Fuzzy Logic Control of Hybrid Energy Storage System Using Two Stage Low‐Pass Filter to Smooth Power Fluctuations in Microgrid

ABSTRACTThe intermittent and fluctuating nature of wind turbine output power is increasingly being recognized as a significant issue adversely impacting the power quality and stability of electrical grids. With the increasing integration of wind power, this challenge cannot be underestimated. However, a potential solution for mitigating the adverse effects of such fluctuations lies in the Hybrid Energy Storage System (HESS), which encompasses battery energy storage systems (BESS) and supercapacitors (SC). The HESS is equipped with flexible operational modes for charging and discharging, thus enabling grid‐connected microgrids to possess the ability to counteract these oscillations. In this article, a control strategy based on the combination of Q‐learning and fuzzy logic control approaches is presented for tuning the parameters of a utilized two‐stage variable time constant low‐pass filter (LPF) in a grid‐connected microgrid. The proposed strategy adaptively tunes the time constants of LPFs to mitigate wind power fluctuations. Furthermore, practical constraints for the energy storage systems and their interfaced converters, such as preventing overcharge/discharge, ramp rate requirements, and certain maximum power conversion ranges, have been taken into account. Numerical simulation results verify the effectiveness of the proposed two‐stage variable time constant LPF for output wind power fluctuation reduction considering practical constraints of HESS.

Life prediction of on-board supercapacitor energy storage system based on gate recurrent unit neural network using sparse monitoring data

With the increasing use of supercapacitor in transportation and energy sectors, service life prediction becomes an important aspect to consider. As the aging process of onboard supercapacitors is closely related to practical working conditions, the actual service life may be inconsistent with the cycle life measured in the laboratory. However, the low-quality onboard monitoring data recording the historical working conditions is usually sparse and fragmented, making it difficult to extract valuable information. In our previous study, we successfully obtained the characteristic parameters from sparse and fragmented data, whereas those characteristic parameters change periodically and couldn't be used directly for life prediction. In this paper, we firstly extract the degradation trend term of supercapacitor by a composite sine and polynomial time series decomposition model from the characteristic parameters. Secondly, in order to make up for the lack of data, a GRU network is designed to generate more sample data which is in consistent with historical data evolution trends. The combination of input characteristic variables including the extracted historical characteristic capacitance C, temperature T and the time fitting sequences CtD are selected to improve the accuracy of GRU predictions. The predictive error of the characteristic capacitance C is 2.36 %. Finally, the life prediction of on-board supercapacitors based on actual working conditions is realized.

Effect of addition of NWCNTs on the performance of carbon black generated using liquid-phase plasma for energy storage in supercapacitors

Effect of addition of NWCNTs on the performance of carbon black generated using liquid-phase plasma for energy storage in supercapacitors

Nanocomposite Material Sb2S3:SnS:MnS2 its Fabrication and Utilization as Efficient Electrode for Energy Storage in Supercapacitor

AbstractThe nanocomposite material Sb2S3: SnS:MnS2 was fabricated by single precursor technique by using dithio‐carbamate ligand as Sb2S3:SnS:MnS2 (DDTC) complex. An internal and external look at the anatomy and activity of the substance was obtained by using a variety of analytical techniques like XRD, FTIR, UV‐Vis and SEM. Additionally, various electro‐analytical tools like LSV, CV, GCD and EIS were applied to confirm material's rich electro‐active capability for photoactive electrode. XRD revealed its average crystallite size of 12.33 nm with 82.8 % crystallinity. Optical characteristics represented describe effective semiconducting nature of nanomaterials with optimum band gap of 2.65 eV. By using electrochemical processes, LSV and CV demonstrated fertile opto‐electrical nature of Sb2S3: SnS: MnS2 (DDTC) material with specific capacitance, Csp, of 1080 F/g at scan rate of 2 mV/s. With a high specific power density of 2656 W/kg, the GCD technique attempted to validate the nature of the material as an electrode with a good charge‐discharge mechanism. In EIS, low series resistance, Rs=0.73 Ω, was observed to be very beneficial argument in validating the nanocomposite synthesized in this research project as effective and low‐cost material which can be applied in different energy producing and storing devices like solar system and super‐capacitors etc.

Solvent-free mechanochemical synthesis of Mg-gallic acid complex for the fabrication of high-performance supercapacitor porous carbon

At molecular level, it is challenging to construct a porous carbon from magnesium based template and low cost precursor by a facile route for supercapacitive energy storage, e.g. solvent-free approach because the coordination of magnesium ion with organic ligands usually needs participation of solvent. Herein, a balling milling mediated coordination of magnesium acetate and gallic acid was developed in the absence of solvent to prepare porous carbon. The key of the present strategy lies in the generation of volatile HAc, orienting the reaction in a favorable direction for the formation of complexes. The resultant porous carbon (denoted BGMC) owns a high microporostiy ratio (24.2 % vs template-free derived ones of 11.1 %), open accessed microstructure and hydrophobic character. As electrode for supercapacitor, in aqueous electrolyte, the BGMC based supercapacitor achieves a high energy density of 19.2 Wh kg−1@900 W kg−1, while, in organic electrolyte of 1.0 M TEABF4/AN, the symmetric device based on BGMC delivers energy in a wide voltage window of 0–3.5 V with large energy of 34.4 Wh kg−1@1750 W kg−1, which is superior to those of recently reported carbon based devices. And more, at high current density of 10 A g−1, the BGMC device can resist continual charge/discharge for 30 000 cycles, showing an excellent cycling stability. Our strategy involving solvent-freely coordination of template and precursor molecule to prepare porous carbon open up a route with facile, scalable and easy-operable attributes towards the preparation of functional porous carbon.

Ternary g-C3N4/Co3O4/CeO2 nanostructured composites for electrochemical energy storage supercapacitors

Extensive use of fossil fuels causes heavy discharge of carbon dioxide, depleting energy resources and this requires environmentally friendly and effective energy storage materials. Hybrid supercapacitors (HSCs) are recently developed as effective energy storage materials enabling high capacitance retention rate and quick charging. Herein, synthesis of two-dimensional g-C3N4 nanosheets supported onto three-dimensional flower-like Co3O4/CeO2 (CoCe) ternary synergistic heterostructures are developed as effective electrodes for hybrid supercapacitor applications. Addition of g-C3N4 produces substantial surface active sites, enabling its synergistic effect with CoCe to enhance electrochemical performance having exceptional conductivity. The CoCe/g-C3N4 ternary composite electrode exhibits a higher specific capacitance of 1088.3 F g−1 at 1 A g-1 with 96 % of recycling stability over 5000 cycles, which is ∼5.5 and ∼5 folds higher specific capacitance than the pristine g-C3N4 and CoCe electrodes. EIS analysis revealed that CoCe/g-C3N4 electrode offered reduced charge transfer resistance compared to pristine electrodes. The fabricated two-electrode HSC device displays outstanding retention after 10,000 cycles with an ultra-high specific capacitance of 119.8 F g−1, excellent energy density 37.4 Wh kg−1 and power density of 749.9 W kg−1. This research showcases the perspectives of CoCe/g-C3N4 ternary electrodes in hybrid supercapacitors and other renewable energy storage devices.

Micro/Meso-Porous Double-Shell Hollow Carbon Spheres through Spatially Confined Pyrolysis for Supercapacitors and Zinc-Ion Capacitor.

Energy storage in supercapacitors and hybrid zinc ion capacitors (ZIC) using porous carbon materials offers a promising alternative method for clean energy solutions. The unique combination of hierarchical porous structure and nitrogen doping in these materials has demonstrated significant capacity for energy storage. Nevertheless, the full potential of these materials, particularly the relationship between pore structure configuration and performance, remains underexplored. Herein, a confined pyrolysis strategy based on the polymerization characteristics of polydopamine (PDA) was developed to construction of hollow carbon spheres with microporous/mesoporous dual shell structure. The depth of micropores and cavity can be controlled by adjusting the duration of heat treatment and hydrothermal treatment, in accordance with the decomposition and polymerization characteristics of PDA. Due to the elasticity of this structure, the relationship between the micro/mesoporous depth of the prepared carbon spheres and the energy storage performance in supercapacitors and ZIC is established. Through optimizing the ion transport capacity of carbon spheres and considering the influence of its internal cavity structure on energy storage, the resulting carbon spheres exhibit high specific capacitance of 389 F g-1 in supercapacitor and specific capacitance of 260 F g-1 and excellent stability with 99.3 % retention after 30000 chare/discharge cycles in ZIC.

Magnetic CuFe2O4 Spinel-Polypyrrole Pseudocapacitive Composites for Energy Storage.

This investigation focused on the fabrication of ceramic ferrimagnetic CuFe2O4-conductive polypyrrole (PPy) composites for energy storage. CuFe2O4 with a crystal size of 20-30 nm and saturation magnetization of 31.4 emu g-1 was prepared by hydrothermal synthesis, and PPy was prepared by chemical polymerization. High-active-mass composite electrodes were fabricated for energy storage in supercapacitors for operation in a sodium sulfate electrolyte. The addition of PPy to CuFe2O4 resulted in a decrease in charge transfer resistance and an increase in capacitance in the range from 1.20 F cm-2 (31 F g-1) to 4.52 F cm-2 (117.4 F g-1) at a 1 mV s-1 sweep rate and from 1.17 F cm-2 (29.9 F g-1) to 4.60 F cm-2 (120.1 F g-1) at a 3 mA cm-2 current density. The composites showed higher capacitance than other magnetic ceramic composites of the same mass containing PPy in the same potential range and exhibited improved cyclic stability. The magnetic behavior of the composites was influenced by the magnetic properties of ferrimagnetic CuFe2O4 and paramagnetic PPy. The composites showed a valuable combination of capacitive and magnetic properties and enriched materials science of magnetic supercapacitors for novel applications based on magnetoelectric and magnetocapacitive properties.

Cascaded utilization of magnetite nanoparticles@onion-like carbons from wastewater purification to supercapacitive energy storage.

Developing high-performance carbon-based materials for environmental and energy-related applications produces solid waste with secondary pollution to the environment at the end of their service lives. It is still challenging to utilize these functional materials in a sustainable manner in different fields. In this study, we demonstrate a cascaded utilization of an Fe3O4@onion-like carbon (Fe3O4@OLC) structure from wastewater adsorbents to a supercapacitor electrode. The structure was formed by carbonizing Fe3O4@oleic acid monodisperse nanoparticles into interconnected Fe3O4@OLCs and subsequent insufficient acid etching. The hollow OLCs in the outside region of the hybrid structure provide high surface area and the encapsulated Fe3O4 nanoparticles in the inside region offer high ferromagnetism. The three-dimensionally interconnected graphitic layers are advantageous for efficient separation and high conductivity. As a result, the maximum saturation adsorption capacity of insufficiently etched interconnected Fe3O4@OLCs can reach up to 90.2 mg g-1 and they can be efficiently separated under a magnetic field. Furthermore, the hybrid structure is thermally transformed into N-doped HOLCs, which are demonstrated to be a high-performance supercapacitor electrode with high specific capacitance and high electrochemical stability. The cascaded utilization of the hybrid structure in this study is meaningful for eco-friendly development of functional materials for environmental and energy storage applications.

Exploring the potential of construction-compatible materials in structural supercapacitors for energy storage in the built environment

As urbanization accelerates, the need for innovative solutions that integrate energy storage within the built environment (BE) becomes increasingly vital for sustainable and multifunctional infrastructure. This review paper delves into the pioneering concept of structural supercapacitors (SSCs), which seamlessly embed energy storage capabilities directly into construction materials such as ordinary portland cement, geopolymers, magnesium phosphate cement, aluminate cement, bricks, wood, and polymers. These materials are readily available and possess inherent structural strength, making them ideal candidates for functionalization as energy storage devices. SSCs rely on the combination of mechanical strength and electrochemical capabilities, allowing structures to serve dual functions—bearing mechanical loads while storing and releasing electrical energy. This review discusses the key components of SSCs, including conductive fillers, electrodes, and electrolytes, and evaluates their electrochemical and mechanical performance. Several critical research gaps have been identified, including the need for alternative conductive fillers to improve ionic conductivity and specific capacitance, advanced additives to enhance multifunctionality and optimization of the interaction between fillers and substrates. Additionally, post-curing treatments and the control of porosity and microstructure require further exploration to balance electrochemical performance with mechanical robustness. Challenges related to integrating SSCs into practical applications, such as environmental durability and mechanical load-bearing capacity, are also highlighted. Furthermore, the potential of 3D printing technology to create customizable SSC structures is identified as a promising area for future research. This review contributes to advancing SSCs and their potential integration into sustainable infrastructure by highlighting the gaps and future directions of the existing literature.

Tailoring MnO2 nanowire defects with K-doping for enhanced electrochemical energy storage in aqueous supercapacitors

The fabrication of supercapacitors with outstanding performance is presented with a distinct defect-rich nanostructures. A one-pot, energy-efficient method for synthesizing defective manganese dioxide nanowires doped with potassium (K0.35MnO2) was developed. The introduction of potassium ions at 35 % birnessite resulted in a significant increase in lattice defects and an improvement in conductivity. Addition of KOH induces a phase transition from α-MnO2 to δ-MnO2. These imperfections result in a greater quantity of active sites, which are crucial for the process of energy storage. The K0.35MnO2 structure demonstrates a 405F/g increased capacity at a current density of 1 A/g. The asymmetric supercapacitor (K0.35MnO2/AC) that was manufactured exhibits a capacitance of 106.4F/g when operating at 1 A/g, while maintaining a maximum energy density of 71.5 Wh kg−1 and a power density of 672 W kg−1. Furthermore, 92.7 % of the initial capacitance of the device is retained even after 8,000 cycles at 20 A/g. This study presents novel insights into the production of defective materials for energy storage applications through the utilization of a one-pot process as opposed to the multi-step method. In order to produce high-performance supercapacitors for practical applications, the results indicate that defect engineering is a crucial factor.

Soft-templating of biomass derivatives into edge-N doped 3D-interconnected hierarchical porous carbon for multi-scenario supercapacitive energy storage

Rational design of the pore structure for carbon materials is of great significance for solving the low specific capacitance and poor rate capability of supercapacitors. A novel soft-templating strategy is proposed by using biomass-derived sodium lignosulphonate as a carbon precursor and sublimable hexamethylenetetramine as a soft template. The hexamethylenetetramine nanoparticles are formed in the confined spaces of the precursor, and then these templates sublime to leave mesopores after the lignosulfonate transformed from linear structure to bulk structure by thermostabilization treatment. A high nitrogen content of 40 wt% in hexamethylenetetramine is also beneficial for the subsequent in-situ N-doping. The as-obtained nitrogen-doped hierarchical porous carbon microspheres possess a high specific surface area of 1416 m2 g−1 with an N-doping content of 4.32 % (86.26 % edge-N). In a two-electrode system, the soft-templating carbon exhibits a decent specific capacitance of 234 F g−1 at 0.1 A g−1, an excellent rate capability of 62.4 % at 50 A g−1, and a high energy density of 8.1 Wh kg−1 at 15.0 kW kg−1 in 6 M KOH aqueous electrolyte. Moreover, advanced additive manufacturing technology of direct ink writing was applied to construct a quasi-solid-state in-plane interdigital microsupercapacitor by using the soft-templating carbon, and it presents a superior areal/volumetric capacitance, rate performance, mechanical stability, and flexibility with PVA/H2SO4 gel electrolyte. This work broadens the pore structure engineering methodology by novel soft-templating biocarbon for multi-functional and multi-scenario energy storage systems.

Bottom-up stripping of graphene with controlled oxidation behaviors towards supercapacitors energy storage

Due to its distinctive two-dimensional planar structure, room temperature quantum Hall effect, and high strength, graphene has garnered significant interest in the fields of energy storage and conversion. In order to achieve high efficiency in the production of graphene, electrochemical peeling has been extensively investigated. Nevertheless, the intermolecular forces between graphite layers are disrupted during ion intercalation in solution, leading to inconsistent bonding forces and low yields. In order to address the issues above, this study introduces a novel bottom-up electrochemical peeling method, wherein graphite expansion occurs above the electrolyte. By preventing contact between the peeled graphene and the electrolyte, the oxidation of graphene is significantly minimized, resulting in a substantial yield of 88 %. At the current density of 1.0 A g−1, the Go-QAS displayed 225.5 F g−1, and kept about 220.2 F g−1 after 500 cycles. The well-designed bottom-up peeling process leads to graphene nanosheets with reduced structural degradation, high purity, and excellent conductivity. This technique is expected to introduce innovative concepts for the field.

Multi-objective optimization of HESS control for optimal frequency regulation in a power system with RE penetration

Concerns over fossil fuel emissions and their hazardous effects have led to a shift away from conventional power plants and focus more on the expansion of renewable energy sources. This shift has resulted in reduced inertia and resulted in poor frequency control within electrical power systems. Hybrid Energy Storage Systems (HESS) have been proposed as an effective solution to enhance frequency stability and address the reduced inertia issue. This research evaluates three distinct control models for HESS, Incorporating Supercapacitor Energy Storage (SCES) and Battery Energy Storage Systems (BESS). To optimize the control parameters with the best objectives, all possible sets of objectives with four different optimization algorithms are studied. The three control models considered for the HESS incorporate Virtual Synchronous Generator (VSG) or Virtual Inertia (VI) control with independent or simultaneous optimization of control parameters. The performances of the three control models are evaluated based on three test scenarios incorporating uncertainties, reduced inertia, and uniform and random load disturbances. The findings indicate that the Independently Optimized Virtual Synchronous Generator HESS (IO VSG-HESS) achieves the best settling time post-contingency but offers the least improvement in frequency nadir with an average of 0.31 %. Conversely, the Simultaneously Optimized Virtual Inertia And Virtual Synchronous Generator Controlled HESS (SO VI-VSG-HESS) excel in mitigating small frequency fluctuations with an average improvement in frequency standard deviation of 87.65 %. The Simultaneously Optimized Virtual Synchronous Generator Controlled HESS (SO VSG-HESS) provides the best frequency nadir, with an average improvement of 0.63 %, but with a slight increase in settling time.

Decoding electrochemical dynamics: Examining the potential of GO/Cu1-xSrxCr2O4 nanocomposite for high-performance supercapacitor energy storage

In this study, pure Cu1-xSrxCr2O4/GO nanoparticles were successfully synthesized via a simple precipitation route followed by calcination at 70 °C for 2 h, resulting in a high-performance supercapacitor nanoelectrode material. Characterization techniques confirmed the formation and properties of the synthesized materials. X-ray diffraction (XRD) analysis revealed the crystalline structure of the nanocomposite, with the d-spacing value of GO changing to 7.6 Å and the presence of peaks indicating the Cu1-xSrxCr2O4 phase. The average crystalline sizes were found to be 13.5 nm for GO, 16.15 nm for CuCr₂O₄, and 21.2 nm for the Cu1-xSrxCr2O4/GO nanocomposite. Scanning electron microscopy (SEM) demonstrated the highly porous nature of the samples, with average grain sizes of 30 nm, 25 nm, and 27.4 nm for GO, CuCr₂O₄, and Cu1-xSrxCr2O4/GO, respectively. Elemental analysis using energy-dispersive X-ray spectroscopy (EDS) confirmed the presence of copper, chromium, and oxygen, along with minor impurities. Raman spectroscopy indicated an increased defect density in the Cu1-xSrxCr2O4/GO nanocomposite, with an ID/IG ratio of 1.57 compared to 1.01 for GO. Photoluminescence (PL) analysis showed a bandgap of 3.65 eV for GO and 2.49 eV for the Cu1-xSrxCr2O4/GO nanocomposite. Electrochemical characterization included electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The EIS analysis showed that the Cu1-xSrxCr2O4 /GO nanocomposite had a lower charge transfer resistance (Rct) of 1.29 Ω compared to GO and CuCr2O4, indicating higher conductivity. The maximum specific capacitance of the Cu1-xSrxCr2O4 /GO nanocomposite was 1935.8 F/g at a scan rate of 3 mV/s in 1 M KOH electrolyte, significantly higher than that of GO alone (480.190 F/g). This study demonstrates the potential of Cu1-xSrxCr2O4/GO nanocomposites as efficient supercapacitor electrode materials, showcasing enhanced capacitance and conductivity due to the synergistic effects of the components.

Phosphorus-doped carbon nitride for enhanced supercapacitor performance and energy storage applications

Exploiting the advantages of graphitic carbon nitride doped with phosphorus (xP-CN) electrodes were designed for high-performance hybrid asymmetric supercapacitor via facile hydrothermal and thermal decomposition techniques. The structural, surface chemistry, functional and morphological characterizations evidence depict successful phosphorus incorporation in Carbon Nitride (CN). X-ray photoelectron spectroscopy analysis shows that phosphorus (P) atoms have replaced corner carbon atoms in the CN structure. These findings clearly demonstrate that the presence of phosphorus doping improves the electrochemical activity of the electrodes. The designed three-electrode system has a specific capacitance of 189.36 F/g with a current density of 1 A/g. Phosphorus doping has been discovered to play a significant role in improving both specific capacitance and cycling stability. The capacitance retention of the two-electrode solid-state device has 97.2 % after 5000 cycles. These electrochemical evaluations reveal that the xP-CN electrode exhibits superior electrochemical performances than pristine CN. This doping strategy for CN presents a novel and efficient approach for crafting high-performance supercapacitors.