Electrode Materials For Supercapacitors Research Articles

Synthesis and characterisation of tamarind seed husk-derived carbon quantum dots incorporated polypyrrole nanosphere composite for energy storage applications

ABSTRACT In this study, the green synthesis of Tamarind Seed Husk-derived carbon quantum dots (TCQDs) by using a facile one-step hydrothermal technique and Tamarind Seed Husk-derived carbon quantum dots/Polypyrrole nanosphere composites (TCQDs/PPy-NS) was synthesised by using the facile in-situ chemical polymerisation method. These results suggest that the TCQDs/PPy-NS composite electrode is a promising electrode for high-energy storage applications. The TCQDs/PPy-NS composite offers an effective supercapacitor electrode material by blending the superior electrical conductivity of TCQDs with the increased pseudocapacitive capacity of polypyrrole nanospheres (PPy-NS). The TCQDs/PPy-NS composite exhibits a specific capacity (Csp) of 400 Fg−1 at a current density (CD) of 2 Ag−1, and a solid-state flexible symmetric supercapacitor (SSC) was developed using the TCQDs/PPy-NS composite to meet an excellent power density (PD) of 1008.19 Wkg−1 at an energy density (ED) of 31.02 Whkg−1 It also demonstrated excellent cycling stability with a capacity retention and coulombic efficiency of 84.57% and 98.06% after 4000 cycles at 2 Ag−1 respectively. This remarkable flexibility and stability make the TCQDs/PPy-NS SSC device highly suitable for applications in wearable electronics and flexible energy storage systems.

Significantly Increased Specific Discharge Capacitance at Carbon Fibers Created via Architected Ultramicropores.

Carbon is commonly used as an electrode material for supercapacitors operating on an electrical double-layer energy storage mechanism. However, the low specific capacitance limits its application. Increasing the specific surface area is by far the most common expansion method, and surprisingly, they are not always positively correlated. The overmuch specific surface will show the characteristics of nanoconfinement, and the potential synergistic enhancement mechanism of various key parameters is still controversial. In this work, carbon fiber electrodes with different ultramicropore structures were designed in order to improve the utilization rate and the discharge capacitance. It has been found that when the ultramicropore entrance's surface is too small, it will lead to the decrease of the external charge of the pore transport channel, and then, the selectivity of the opposite ions will decrease. The numerical simulation based on Poisson and Nernst-Planck equations also indicates that ions have difficulty diffusing into the micropores when their entrance surface decreases. Surface properties within the nanocontainment space become critical factors influencing ion transport and adsorption. The specific discharge capacitance of carbon fiber is increased from 3 to 1430 mF cm-2.

Solvothermal synthesis of CuS nanosheets loaded porous carbon electrode composites for high performance supercapacitors

In this work, an electrode composite (CuS-NPC) for supercapacitors was synthesized by loading hexagonal nano-sheeted copper sulfide onto porous carbon through a solvothermal reaction using thiourea and copper acetate as the sulfur and copper sources, respectively. The synergistic effect of nanoscale copper sulfide sheet and hierarchical pore structure of porous carbon with high surface area achieves excellent capacitive performance in electrochemical reactions. CuS-NPC exhibited a large specific capacitance of 1298.7F g−1 at current density of 0.5 A/g and 766.3F g−1 at current density of 10 A/g, revealing that the electrode composite of copper sulfide and porous carbon have a great prospect as a supercapacitor electrode material.

Conversion of cobalt from spent LIBs to Co3O4 electrode material for application in supercapacitors

ABSTRACT The cathode material of lithium-ion batteries (LIBs) is endowed with valuable metals, such as cobalt. The improper treatment of these batteries pollutes the environment and causes enormous resource waste. Therefore, the recovery of valuable metals from spent LIBs has attracted widespread attention. In this study, Co3O4 electrode materials were prepared by a simple homogeneous precipitation method and heat treatment using a leaching solution of spent LIBs-positive electrode material as the cobalt source. The crystal structure and morphology of the products were examined at different annealing temperatures, and their electrochemical performance was analyzed. The results show that low-temperature annealing contributes to grain refinement. The Co3O4 material prepared at 300°C annealing temperature has a rod-like structure with distinct pores and a specific surface area of 58.98 m2 g−1. Furthermore, electrochemical performance testing reveals that Co3O4 prepared at 300°C displays the best electrochemical performance as an electrode material, with a specific capacitance of 97.93 F g−1 and a cycle retention rate of 79.12% after 500 charge–discharge cycles. These findings demonstrate the feasibility of recycling valuable metal cobalt from spent LIBs cathode materials to produce Co3O4 materials for use as supercapacitor electrode materials, opening up new avenues for the recycling and utilisation of spent LIBs.

Advancing electrochemical activity: Insights from Li doped Ni-MOF synthesis and performance

This study presents the first-time synthesis of a novel Li doped Ni-MOF electrode material, achieved via a one-step hydrothermal strategy. Microstructural analysis using FESEM and HRTEM revealed hierarchical hollow spherical-like nanostructures within the Li doped Ni-MOF, providing abundant active sites for ion transport and storage. This structural feature resulted in enhanced specific capacity, exhibiting battery-like behaviors. Specifically, the Li doped Ni-MOF electrode displayed a notable specific capacity of 214.2 C/g in CV curves at 0.5 mV/s and 814 C/g in GCD curves at 1 A/g. These findings underscore the potential of the Li doped Ni-MOF as a superior electrode material for supercapacitors, indicating its promising prospects for advancing next-generation high-performance energy storage devices.

Oxalate and adipate mediated fabrication of CuO nanocrystallites for their electrochemical and supercapacitance studies

Cupric oxide (CuO) has been comprehensively studied in the field of electrochemistry due to its high Tc-Superconducting property. The present work focus on two different CuO materials i.e. CuO-1 and CuO-2 nanocrystallites which are successfully synthesized from their oxalate and adipate precursors respectively. The calcination temperature for the synthesis of CuO from their precursors is ascertained by TGA analysis of the dicarboxylates. Both the CuO materials are thoroughly characterized by SEM–EDS, XRD, IR and XPS spectroscopic techniques. As a candidate for supercapacitor electrode material, CuO-1/C and CuO-2/C showed a specific capacitance of 4.15 F/g and 22.24 F/g using cyclic voltammetry, 10.4 F/g and 46.6 F/g using GCD curves respectively at a current density of 1 A/g. Also, the CuO-1/C and CuO-2/C showed a specific energy density (Es) 1.59 Wh kg−1 and 0.36 Wh kg−1 at a specific power density (Ps) of 0.02 kW kg−1 and 0.025 kW kg−1 respectively. Moreover, the CuO-2/C exhibits ≈ 96.1% coulombic efficiency following 1000 cycles, whereas, CuO-1/C lags in coulombic efficiency with only 51.8%. As a better candidate, CuO-2/C exhibited excellent rate capability with an outstanding cycling stability of 93.7% retention after 1,000 cycles. The factors contributing to the significant specific capacitance of CuO-2/C along with better stability and reproducibility are its low electrolyte resistance Rs (2.47Ω) and charge transfer resistance Rct (1.01 Ω).

Nitrogen configuration modulation of porous graphitic carbon nanosheets for superior capacitive energy storage

Carbon nanosheets with layer-stacked porous structures and surface functionalized groups are beneficial for efficient ion storage in supercapacitor electrode materials, but achieving high cost-effectiveness and controllable surface groups remains a significant challenge. Herein, the biomass-derived chitosan and sodium alginate are selected as raw materials for self-assembly reaction with phytic acid as a cross-linking agent. The protonated chitosan and sodium alginate form a cross-linked network structure through hydrogen bonding and electrostatic adsorption, which is subsequently carbonized and activated to synthesize porous graphitic carbon nanosheets (PNPCN-X). PNPCN-X realizes an efficient distribution of porous and graphitic structures. It's noteworthy that phytic acid facilitates the fixation of N atoms, and various N configurations can be adjusted by altering the content of phytic acid. Optimized PNPCN-1.5 exhibits a high content of structurally stable pyridinic-N and graphitic-N configurations, which are confirmed to serve as active sites substantially augmenting the ion adsorption capacity through Density Functional Theory (DFT) calculations. Benefiting from its exceptional physicochemical properties, PNPCN-1.5 achieves 322 F g−1 as electrode materials in the three-electrode system, while the symmetrical supercapacitor assembled with EMIMBF4 electrolyte attains 56.29 W h kg−1. Furthermore, various kinetic analyses extensively elucidate its capacitance distribution characteristics and ion diffusion rates.

Stable Hierarchical Porous Heterostructure Ni2P/NC@CoNi2S4 Fabricated via the NiCo-LDH Template Strategy for High-Performance Supercapacitors.

Transition metal phosphide/sulfide (TMP/TMS) heterostructures are attractive supercapacitor electrode materials due to their rapid redox reaction kinetics. However, the limited active sites and weak interfacial interactions result in undesirable electrochemical performance. Herein, based on constructing the NiCo-LDH template on Ni-MOF-derived Ni2P/NC, Ni2P/NC@CoNi2S4 with a porous heterostructure is fabricated by sulfurizing the intermediate and is used for supercapacitors. The exposed Ni sites in the phosphating-obtained Ni2P/NC coordinate with OH- to in situ form an intimate-connected Ni2P/NC@NiCo-LDH, and the CoNi2S4 nanosheets retaining the original cross-linked structure of NiCo-LDH integrate the porous carbon skeleton of Ni2P/NC to yield a hierarchical pore structure with rich electroactive sites. The conducting carbon backbone and the intense electronic interactions at the interface accelerate electron transfer, and the hierarchical pores offer sufficient ion diffusion paths to accelerate redox reactions. These confer Ni2P/NC@CoNi2S4 with a high specific capacitance of 2499 F·g-1 at 1 A·g-1. The NiCo-LDH template producing a tight interfacial connection, significantly enhances the stability of the heterostructure, leading to a 91.89% capacitance retention after 10,000 cycles. Moreover, the fabricated Ni2P/NC@CoNi2S4//NC asymmetric supercapacitor exhibits an excellent energy density of 73.68 Wh kg-1 at a power density of 700 W kg-1, superior to most reported composites of TMPs or TMSs.

Microwave irradiation effect of La2O3-CeO2 nanocomposites as a potential electrode material for asymmetric supercapacitor

Microwave irradiation effect of La2O3-CeO2 nanocomposites as a potential electrode material for asymmetric supercapacitor

Cr-Substituted SrCoO3-δ Perovskite with Abundant Oxygen Vacancies for High-Energy and Durable Low-Temperature Antifreezing Flexible Supercapacitor.

Developing high-performance electrodes for flexible antifreezing energy storage devices has been a significant challenge with the increasing demand for portable components. In this work, Cr-substituted SrCoO3-δ perovskites were first proposed as potential low-temperature supercapacitor electrode materials. The high-valence Cr6+ ([Ne]3s23p6) substitution favors a high-spin state of Co ions with enhanced electronic repulsion effect, ultimately forming a stable cubic structure with high conductivity. Accordingly, the modification strategies of SrCoO3 through the p6 configuration cation substitution have been improved. As a result, the asymmetric SrCo0.95Cr0.05O3-δ@CC//PPy@CC device exhibited a high energy density of 44.90 Wh kg-1 at 902.01 W kg-1 and maintained a 95.8% specific capacitance after 10,000 cycles, demonstrating an ultralong cyclic stability. The dramatically improved electrochemical performance was attributed to the stabilized crystal structure, increased oxygen vacancy, and accelerated oxygen diffusion rate. Furthermore, a quasi-solid-state supercapacitor with ethylene glycol (EG)-modified KOH/PVA organohydrogel electrolyte was developed through an advance in situ-integrated strategy. After bending at 180° for 1000 cycles, only a 9.7% capacity decay was observed. Even under -40 °C, the supercapacitor has a large energy density of 46.94 μWh cm-2. The present work represents the initial investigation into utilizing perovskite materials for antifreezing energy storage device, thereby confirming their potential application as low-temperature electronic components.

High performance symmetric supercapacitors based on Au incorporated CrN thin films fabricated by reactive magnetron sputtering

Recently, transition metal nitrides are being investigated extensively as potential supercapacitor material. In the present study, Au incorporated CrN (Au_CrN) thin films have been synthesized using reactive magnetron co-sputtering technique for application as supercapacitor electrode material. Films have been prepared at different Ar to N2 flow rates keeping total deposition pressure constant to achieve the required structural phase in the sample. Electrochemical properties of the deposited materials have been investigated with a three-electrode system in 0.5 M H2SO4 aqueous electrolyte. The CrN thin film deposited under 3:1 Ar: N2 partial pressure or flow rate ratio shows the highest specific capacitance. Upon Au incorporation, the film shows an areal capacitance of 56.8 mFcm−2 at 1.0 mAcm−2discharge current density which is an almost nine-fold enhancement in specific capacitance value compared to pristine CrN sample. Symmetric supercapacitors have also been developed by sandwiching two identical Au_CrN thin film electrodes, which have found to deliver excellent specific capacitance of 86.03 mFcm−2at 1.0 mAcm−2 discharge current density with no decline in capacitance value till 20,000 cycles. Furthermore, it can deliver a high energy density of 52.02mWhcm−2and a power density of 0.12mWcm−2. The electrochemical properties of the supercapacitors fabricated with the Au_CrN thin film electrodes are found to be better than most of the results reported so far in the literature with CrN electrodes. Results of the present study clearly demonstrate that these Au enhanced CrN films prepared by easily scalable and highly reproducible magnetron sputtering technique have great potential as a high capacitance supercapacitor electrode material.

Dense graphene composite hydrogels as advanced electrode materials for high-performance supercapacitors

In this work, alanine functionalized nanocellulose/graphene composite hydrogels (NCGHalas) were prepared via an easy hydrothermal reaction using alanine, GO, and nanocellulose as reactant. Thanks to this synthesis strategy, NCGHalas exhibited large bulk density, abundant heteroatom functional groups, reasonable porous structure and moderate specific surface area. Based on the above characteristics, the aqueous symmetric supercapacitors (ASSC) assembled by NCGHala25 presented high gravimetric and volumetric specific capacitance of 276.5 F g−1 and 320.8 F cm−3 at 0.3 A g−1, excellent rate performance (77.9 % at 10 A g−1), and long working life of 95.4 % retention after 10,000 cycles at 10 A g−1. Furthermore, the NCGHala25 based ASSC also exhibited large gravimetric and volumetric specific energy densities of 9.6 Wh kg−1 and 11.1 Wh L−1. More importantly, the flexible solid-state supercapacitors (FSSC) fabricated by NCGHala25 and PVA-KOH electrolyte delivered high specific capacitance (178.2 F g−1, 0.3 A g−1), and this value can be maintained for 74.2 % even at 10 A g−1.

Self-assembled from monometallic-organic framework to bimetallic-organic framework materials with promoted supercapacitor performance

Designing new metal–organic frameworks (MOFs) materials with definite structure and introducing heterometallic atom is an effective strategy to develop new electrocatalytic and energy storage materials. Herein, one new 3D close-packed type manganese metal–organic frameworks, namely [Mn2(BPTC)(DMSO)2.5] (Mn-MOF) have been constructed from a rigid biphenylic acid with a rigid biphenyl-3,3′,5,5′-tetracarboxylic acid (H4BPTC) ligand under a solvothermal condition. Besides, adopting the metal doping strategy, a series of bimetallic MnM’-MOF (M’=Co, Ni and Cu) crystalline materials has been successfully grown on nickel foam (NF) and were used for supercapacitor electrode material. By contrast, the MnNi-MOF/NF shows a specific capacitance of 3391.7 mF cm−2 at 1 mA‧cm−2 in 1.0 M KOH, which is 1.6 times that of Mn-MOF/NF electrode. It also displays excellent cycle stability to keep 92.6 % of the initial capacity after GCD 20000 cycles. Finally, a hybrid supercapacitor (HSC) made from on the MnNi-MOF electrode and activated carbon (AC) could deliver an energy density of 0.224 mWh cm−2 at a power density of 1.04 mW cm−2, and a high cycle-to-cycle stability with 90.1 % of the primary capacitance over 20,000 cycles. This work not only confirms the potential supercapacitor properties of as-synthesized new Mn-MOF, but also effectively improves the specific capacity and device stability of pure Mn-MOF by introducing different transition metal ions.

High-performance asymmetric supercapacitor based on hierarchical hydrothermally grown CuS nanostructures

In this work, various hierarchical CuS were fabricated via an efficient one-step hydrothermal process with different surfactants (polyvinyl pyrrolidine (CS-P), Citric acid (CS-C), Oleic acid (CS-O)) and examined as electrode materials for supercapacitors. XRD, FESEM, HRTEM and BET analysis reveal the fabrication of a hexagonal crystal structure with porous microspheres of CuS-PVP having a BJH pore diameter of 16.241 nm. Among these, the CS-P electrode exhibits a superior specific capacitance of 414.28F/g at 1 A/g of current density in the KOH electrolyte. Additionally, an asymmetric supercapacitor built with CS-P as positive and Activated carbon as negative electrodes exhibited a specific energy of 27.95 Wh/kg at 624.96 W/kg of specific power at 2 A/g and demonstrated outstanding cycling stability with 80.6 % persistence of capacitance for 2500 GCD cycles at 10 A/g. Additionally, an ASC device created for use in real life and tested by charging it for 30 s managed to reach a 3-minute 50-second self-discharging duration. Hence, these favourable electrochemical findings indicate that the hydrothermally grown hierarchical CuS-PVP electrode is a bright potential material in energy storage applications.

Direct pyrolysis fabrication of N/O/S self-doping hierarchical porous carbon from Platycladus Orientali leaves for supercapacitor

To meet the growing market requirement for low-cost supercapacitor electrode materials, N/O/S self-doping hierarchical porous carbon is successfully fabricated by direct pyrolysis of platycladus orientalLeaves (POL). The obtained carbon material exhibits wide application prospects, because of simple and green-environmental technology, low-cost and satisfactory electrochemical properties, which avoided complex preparation routes and consumption of expensive chemical reagents in the traditional activation process. Under the optimum pyrolysis temperature (850 °C), the obtained POL-derived carbon (POL-850) possesses a high specific surface area (1140.2 m2g−1), sheet-like hierarchical porous microstructure, and uniform ternary heteroatoms co-doping (O: 6.79 at.%; N: 3.45 at.% and S: 2.20 at.%). As an electrode material for supercapacitor, the specific capacitance of the POL-850 reaches 224.4 Fg−1 of 0.5 Ag−1and 156.0 Fg−1 at 30 Ag−1, revealing excellent rate performance. The capacitance retention maintains 96.3 % after 10,000 consecutive charge-discharge cycles at 20 Ag−1, demonstrating superior cycling stability. Additionally, the assembled carbon-based symmetric supercapacitor device delivers a satisfied energy density of 11.0 Wh kg−1 with the power density of 65 W kg−1 and ultralong cycle-lifetime with 95.65 % capacitance retention after 10,000 charge/discharge cycles, while the Coulombic efficiency is retaining up to approximately 100 %. This work provides an easy and cost-effective way to rapidly prepare N/O/S co-doping hierarchical porous carbon for supercapacitors, which is very suitable for large-scale production.

Effect of hydrochloric acid on the properties of Ni-MOF nanostructures as supercapacitor electrode materials

In this paper, we investigate the effect of hydrochloric acid on the energy storage characteristics of nickel-based metal–organic framework (Ni-MOF) nanostructures. Electrochemical tests reveal that Ni-MOF exhibit high capacitance under hydrochloric acid regulation, achieving a current density of 2567.23 F/g at 2 A/g in 1 ml. Additionally, the synthesized Ni-MOF demonstrate low electrical resistance, with a resistance (Rs) of 1.209 Ω at a hydrochloric acid volume of 1 ml. After 5000 cycles of galvanostatic charge–discharge testing, the cycle retention efficiency of Ni-MOF-0.5 ml remains at 85.71 %.

Enhanced electrochemical performance of rGO/CuBi2O4 as an advance electrode for supercapacitor applications

This study reports the fabrication of pristine CuBi2O4 (CBO) and rGO/CBO nanocomposite by hydrothermal approach. rGO/CBO nanocomposite morphological and structural properties were confirmed via various techniques. rGO/CBO nanocomposite demonstrated capacitance of 1426F/g and a power density (Pd) of 225W/kg @ 1A/g through electrochemical studies. rGO/CBO demonstrated a charge transfer resistance of 1.76 Ω smaller than CBO (2.62 Ω) determined through the Nyquist plot. rGO addition to CBO, quicker charge ion transportation enhanced conductivity and increase in capacitance. rGO/CBO nanocomposite exhibited excellent stability over the 5000th cycle. Therefore, rGO/CBO nanocomposite is a viable option to be employed as supercapacitor electrode material and is also utilized in various energy storage devices.

Design and fabrication of reduced graphene oxide (RGO) incorporated NiCo2S4 hybrid composites as electrode materials for high performance supercapacitors

One of the most promising bimetallic sulphides for use in energy-storage systems is NiCo2S4, but further research is required to give it a high reversibility and electrochemical reaction capacity. In this study, we show the rational materials design of an ideal NiCo2S4 nanoparticle as a NiCo2S4/RGO nanocomposite, embedded in a reduced graphene oxide (RGO) matrix. NiCo2S4 nanoparticles, which ranged in size from 20 to 25 nm and were firmly fixed on the surface of RGO sheets, made up the produced composite. As predicted, the produced nanocomposite displayed a high specific surface area, a mesoporous structure, and high conductivity, resulting in a large electroactive area and rapid electron and ion motion. Additionally, we present the advancements in material science, showcasing the NiCo2S4/RGO nanocomposite electrode, which has a long cycle life of 5000 cycles, a high capacitance retention of 85.6 %, and an exceptional specific capacitance of 1505 Fg-1 at 1 Ag-1. A high active-material loading asymmetric supercapacitor serves as an example of the real-world use. The NiCo2S4/RGO nanocomposite exhibits an exceptional 48 Whkg-1 energy density at a power density of 985 Whkg-1, while maintaining a high power density of 7227 Wkg-1 density of 25 Whkg-1. The exceptional stability and electrochemical efficiency of the NiCo2S4/RGO nanocomposite validate that our methodical materials science and technology optimisation in the areas of active substance synthesis, electrode expansion, and device design/fabrication will help advance the development of high-performance supercapacitors in future years.

Metal-organic frameworks and composites on their basis: structure, synthesis methods, electrochemical properties and application prospects (a review)

Various types of metal-organic frameworks (MOF) and their structural parameters have been reviewed and their classification has been presented. Most widely used synthesis methods and approaches for MOF and composites on their basis have been discussed. MOF structure is a regular 3D lattice formed by organic linkers and metallic clusters. It has been shown for an example of literary data on MOF synthesis and structural studies that the types of bonds and metals can strongly affect the spatial structure and dimensions of MOF crystals: they can have nano-, micro- and meso-dimensions, be dense or porous, bulk or layered. This variety of structural parameters determines the wide range of their properties and potential applications. Prospects and methods of controlling the shapes of the crystals, their size and spatial bonds between organic components and metal ions have been reviewed. Major attention has been paid to zeolite-like frameworks (ZIF) as the most promising ones from the viewpoint of structure, synthesis and electrochemical current source applications. Discussion has touched on possible modifications and methods of controlling the properties of those MOFs and composites on their basis and introduction of impurities, including those having magnetic properties. Possible synthesis options of complex composites through controlled MOF pyrolysis have been presented, for either small-batch or scalable processes. The effect of heat treatment conditions on the final properties and electrochemical applications of those materials has been demonstrated. ZIF-67 structured MOF doping with one more metal has been presented as variant of modifying the properties of MOF and composites on their basis. For example, the Authors have implemented cobalt MOF synthesis wherein cobalt is partially substituted for manganese at the synthesis stage. Furthermore, a simple water solution co-deposition synthesis technique has been modified with ultrasonication thus reducing the time consumption of the process. Electrochemical studies have shown that the unit electrochemical capacity of pyrolyzed MOF electrodes with partial cobalt substitution for manganese is appreciably higher as compared to the manganese-free materials. The unit capacity and energy density increase with manganese content in the MOF. MOF manganese doping delivers a considerable improvement in the electrochemical parameters of the electrode materials for hybrid supercapacitors on their basis (from 100 to 298 F/g at 0.25 A/g current density). The results suggest that cobalt substitution for manganese is an effective method of improving the electrochemical parameters of MOFs. It has been demonstrated that the development of new approaches to the design of MOF based composite materials and the study of the physicochemical regularities of their interaction with various carriers is an important task.

Study on the properties of electrode materials for supercapacitors based on 1D Co-MOCPs

Three one-dimensional (1D) Co-MOCPs (23PCo-S1, 23PCo-S2, and 23PCo-S3; where 23P denotes the ligand, 2,3-pyridine dicarboxylic acid) were synthesized using a similar hydrothermal method. The molecular formulas for the isomers 23PCo-S1 and 23PCo-S2 are [Co(23P)3H2O], while that for 23PCo-S3 is [Co(23P)2H2O]. These single-crystal structures are classified into the P-1, Pca21, and P21/c space groups, displaying triclinic, orthogonal, and monoclinic symmetries, respectively. Techniques such as S-XRD, P-XRD, XPS, and SEM were applied to analyze the structures and valence states of the materials. Additionally, the electrochemical properties of the structures were evaluated using a three-electrode setup. Among these, 23P-Co-S2 demonstrated a remarkable specific capacitance of 458.5 F g–1 at a current density of 1 A g–1. In contrast, 23P-Co-S1 and 23P-Co-S2 showed specific capacitances of 192.2 and 270.6 F g–1, respectively, under the same experimental conditions.