High Specific Capacitance Research Articles

High entropy Prussian Blue Analogues assisted by reduced graphene oxide for enhancing the lifespan of Sodium-ion batteries

In recent years, Prussian blue analogues (PBAs) have been regarded as one of the most promising cathode materials for Sodium-ion batteries (SIBs) due to their open structure, low cost, and high theoretical capacity. However, the problem of capacity degradation caused by phase transitions during the charge/discharge process has so far limited the applicability of PBAs. While the high entropy strategy can alleviate capacity decay induced by phase transitions, challenges such as low conductivity, material aggregation, and severe interface reactions between electrode materials and electrolytes still persist. Therefore, we used a simple and scalable one-step co-precipitation method to grow high entropy Prussian blue analogues (HEPBA) on reduced graphene oxide (rGO) to address these problems. The rGO not only inhibits material agglomeration but also separates the electrolyte from the electrode material to prevent severe interface reactions. Meanwhile, the Warburg impedance is reduced and the Na+ diffusion performance is improved. When high entropy Prussian blue grown on an rGO matrix (HEPBA@rGO) is utilized as the cathode in a half-cell, it exhibits high discharge specific capacity (115.2 mAh g−1 at 100 mA g−1), long cycling stability (retaining 84.6 mAh g−1 after 1000 cycles), and good rate capability (62 mAh g−1 at 15 C). The full battery with HEPBA@rGO as the cathode and hard carbon as the anode has a high specific discharge capacity (100.12 mAh g−1 at 100 mA g−1), good stability (capacity retention rate of 81 % after 150 charge/discharge cycles), and good rate performance (72.5 mAh g−1 at 5 C). This study provides valuable insights for the development of SIBs.

All roads lead to Rome: Trace water-dominated the formation of nanosheet-assembled hollow metal-organic frameworks for high performance supercapacitors

Controlling the structure of metal-organic frameworks (MOFs) is a crucial strategy to enhance electrochemical performance. In this work, nanosheet-assembled hollow Ni-MOF spheres are synthesized by controlling the transition states through a facile trace water-assisted solvothermal method. During the research, it is found that water in the system, whether from the precursor Ni(NO3)2·6H2O or from an additional source, is a key influencing factor that can regulate the reaction process to control structural changes. Theoretical calculations prove that the water present in the reaction system can affect the distribution of terephthalic acid (TPA) and Ni2+, indicating that trace water can provide an accelerating effect. The nanosheet-assembled sphere shells can expose more active surface area, and the hollow structure can prevent the restacking of nanosheets and shorten the charge transport path. Based on these structural advantages, the prepared Ni-TPA MOF electrode achieves a high specific capacitance of 1010 F g−1 at 1 A g−1 and a 61 % rate capability at 20 A g−1. This work offers a feasible and highly effective strategy to design nanosheet-assembled hollow MOF spheres for high-performance supercapacitors and helps to understand the key factors influencing the formation of hollow MOF spheres.

MXene-based conductive hydrogels with toughness and self-healing enhancement by metal coordination for flexible electronic devices

MXene-based conductive hydrogels have emerged as a new type of soft materials in flexible electronics. Herein, metal coordination is introduced into MXene-based conductive hydrogels to synchronously enhance the mechanical and self-healing properties. MXene-based conductive hydrogels are made up of polyacrylic acid (PAA), sium carboxymethyl cellulose (SCMC), Ti3C2TX and metal ions (Ni2+, Al3+ or Sn4+). PAA/SCMC/Ti3C2TX/Sn4+ hydrogel is found to have excellent mechanical (stress: 122 kPa; strain: 1688 %; toughness: 0.95 ± 0.12 MJ m−3) and self-healing (self-healing efficiency: 99.27 % (conductivity); 81.16 % (stress); and 83.13 % (strain)) properties due to the metal coordination and H-bonding. The hydrogel has also good conductivity of 0.82 S m−1 and adhesion of 38.94 kPa. The flexible sensors based on this hydrogel can efficiently detect human motions, electromyography (EMG), electrocardiography (ECG) and handwriting signals. Furthermore, a supercapacitor assembled from this hydrogel has a high specific capacitance of 118.66 F g−1 and good stability (15000 charge-discharge cycles). This work provides an effective strategy for exploiting mechanically tough and self-healing MXene-based conductive hydrogels with prospective applications in flexible electronics.

Facilitating ion transport in porous chemically bonded black phosphorene/MXene heterostructured films for flexible high-rate supercapacitors

Developing thick MXene-based electrodes for supercapacitors (SCs) that possess both high specific capacitance and exceptional rate performance has become a critical research focus. However, MXene-based electrodes often face challenges related to the complex and elongated ion diffusion pathway caused by their large aspect ratio and nanosheet restacking, limiting the rate performance. Herein, we propose fabricating porous chemically bonded black phosphorene/Ti3C2Tx heterostructured films co-doped with S/N heteroatoms via electrostatic self-assembly followed by thermal foaming. The incorporation of black phosphorene serves to effectively prevent the restacking of Ti3C2Tx, while the porous structure enhances ion transport. Additionally, the doped heteroatoms significantly boost the electrochemical activity of Ti3C2Tx. The porous films of approximately 50 μm thickness demonstrate a high capacitance of 374 F g-1 at 0.5 A g-1, retaining 84% of the capacitance at 20 A g-1, thereby enabling the assembled SCs to deliver excellent rate performance. This work presents a promising and innovative approach for the development of high-rate MXene-based SCs.

Strategically designed multiwalled carbon nanotube/bismuth ferrite/polyaniline nanocomposites and unlocking their potential for advanced supercapacitors

Bismuth ferrite (BF) serves a potential electrode-active material due to its peculiar characteristics such as wide voltage window and high specific capacitance, excellent stability, facile synthesis routes, etc. to name a few. Herein we report the strategic design and facile synthesis of multiwalled carbon nanotubes (MWCNT)/BF/polyaniline (PANI) nanocomposites, particularly for application in advanced supercapacitors. The MWCNT/BF/PANI nanocomposite architecture is a strategic design in which the maximum available surface area is utilized for the electrode nanostructure with increased porosity that allows easy movement of electrolyte-ions through it. The uniform arrangement of BF on MWCNTs helps in mitigating the possible agglomeration, further augmenting the surface area for an enhanced charge storage. The strategic layout of PANI on BF-decorated MWCNTs has given a coral-like structure for the nanocomposite electrode which significantly increased the surface area, reduced ion pathways and facilitating better access to electrolytic K+ ions. The MWCNT/BF/PANI nanocomposite electrode exhibits a specific capacitance of 3640 F g−1 at a current density of 5 A g−1. The innovative design as well as the synergy between the individual components of the nanocomposite electrode play a pivotal role in attaining the enhanced electrochemical performance.

Strategically-designed hierarchical polypyrrole-modified manganese-doped tin disulfide (SnS2) nanocomposite electrodes for supercapatteries with high specific capacity

Supercapatteries are novel energy storage devices possessing features of both supercapacitor and battery and evolved to meet the demand for portable electronic devices. An efficient electrode-active material is an important criterion for the fabrication of high performance supercapatteries. We hereby report the rapid synthesis of manganese (Mn)-doped tin disulfide (SnS2) by microwave-assisted hydrothermal method and further use it as an efficient electrode material (positrode) to fabricate a supercapattery. Dunn's kinetic method is adopted to estimate the contribution from the battery-type charge storage which confirm the electrode exhibits charge storage via diffusion-controlled mechanisms. The Mn-doped SnS2 electrode exhibits a specific capacity of 275.4 C g-1 at a scan rate of 10 mV s-1. The specific capacity is further increased by preparing nanocomposite electrodes with polypyrrole at different ratios. The polypyrrole-modified Mn-doped SnS2 electrode delivers a specific capacity of 539 C g-1 at a scan rate of 10 mV s-1. In order to understand its applicability in practical devices, a supercapattery cell is fabricated with polypyrrole-modified Mn-doped SnS2 as positrode and activated carbon as negatrode, which exhibits a mass specific capacity of 204.2 C g-1 along with an area specific capacity of 2.4 C cm-2 at a current density of 2 A g-1. The supercapattery cell possesses an energy density of 42.5 W h kg-1 with a corresponding power density of 2500 W kg-1 at a current density of 2 A g-1. This study proclaims that the polypyrrole-modified Mn-doped SnS2 is an efficient positrode for application in high-performance supercapatteries.

Revealing the interfacial chemistry of silicon anodes with polysiloxane electrolyte additives

Silicon (Si) anodes are promising in lithium-ion batteries owing to their high specific capacity and suitable voltage platform. However, particle volume expansion (>300 %) and the continuous consumption of Li+ to form new interfacial layers result in poor cycle performance. We report a sustainable low-cost Si material derived from photovoltaic cutting waste, showing a high initial Coulombic efficiency (86.9 %). The cycle stability of Si/graphite is enhanced in terms of a 38 % capacity retention increase in the presence of vinyl-terminated polydimethylsiloxane (Vi-PDMS) additive. The C = C bond in Vi-PDMS plays a role in reacting with hydrogen fluoride (HF) by-products to prevent the side reaction between HF and solvent. The decomposed macromolecule Si-containing Li salt serves as a part of the solid electrolyte interphase film and has low interface resistance. This formed interphase layer effectively mitigates stress concentration at the contact surface between silicon particles and the current collector caused by expansion forces.

Experimental investigation of humidified air condensation in different rows of serpantine heat exchanger – Cooling water flow rate effect

Condensing economizers are used in the industry as they enable the acquisition of additional heat during vapor condensation. In condensing heat exchangers, water is the usual cooling agent due to its high specific heat capacity and thus efficient heat removal. Therefore, experiments of hot humid air condensation in a serpentine economizer being cooled by water were performed to reveal the effect the cooling water flow rate has on humidified air condensation in separate rows of the serpentine type economizer (with vertical tubes). The results have shown that the cooling ratio (mass flow ratio between the coolant and the humid air) had a minor effect on the distribution of the humidified air temperature along test section for inlet Reynolds number of 3000–10000. The effects on the condensation flux distribution in different rows were much stronger. The most optimal cooling ratio was determined to be 3. The results have shown that the biggest condensation efficiency is up to 35%. It was revealed that in some cases the convection was prevailing in the first rows of the economizer and this resulted in a decreased efficiency/performance of the exchanger.The obtained results from the practical point of view will provide an extended basis for the optimisation of the design of economizers for waste heat recovery in the cases of different cooling water flow rates. It could also be applied to validate computational models developed for condensation heat transfer and condensate flux numerical modelling along economizer.

The MOFs derived Co, Zn co-doping porous carbon framework as the collector for stable Li metal anodes

The Li metal anode is regarded as the most potential electrode material in the next-generation energy storage system, because of the high energy density and specific capacity. However, the advancement of Li metal anode is restricted by the volume changing and dendrite growth. In this paper, the Co and Zn co-doped porous carbon framework (CF-CZ) derived from MOF structure was designed and produced to realize the dendrite-free Li metal anode. The porous structure could accommodate the deposited Li metal, which relaxes the pressure of electrode structure and relieves the volume changes. Meanwhile, the Co, Zn co-doping effectively improves the lithiophilicity of framework, which attracts Li+ and decreases the nucleation barrier. Besides, numerous micropores of MOF structure could divide the Li+ flux to reduce the local current density for dense sedimentation. With the synergies of co-doping and porous structure, the symmetric cell of CF-CZ shows better electrochemical performance (the overvoltage can be stable at 14 mV after 1200 cycles) than pure Cu foil, and the LFP cells deliver 116.4 mAh g−1 at 1 C after 200 cycles. As a consequence, the CF-CZ possesses the potential to be applied in Li metal anodes.

3,6-Dimethoxythieno[3,2-b]thiophene-Based Bifunctional Electrodes for High-Performance Electrochromic Supercapacitors Prepared by One-Step Electrodeposition.

An integrated visual energy system consisting of conjugated polymer electrodes is promising for combining electrochromism with energy storage. In this work, we obtained copolymer bifunctional electrodes poly(3,6-dimethoxythieno[3,2-b]thiophene-co-2,3-dihydrothieno[3,4-b][1,4]dioxin-3-ylmethanol)(P(TT-OMe-co-EDTM)) by one-step electrochemical copolymerization, which exhibits favorable electrochromic and capacitive energy storage properties. Because of the synergistic effect of PTT-OMe and PEDTM, the prepared copolymers show better flexibility. Moreover, the morphology and electrochemical properties of the copolymers could be adjusted by depositing different molar ratios of 3,6-dimethoxythieno[3,2-b]thiophene (TT-OMe) and 2,3-dihydrothieno[3,4-b][1,4] dioxin-3-ylmethanol (EDTM). The P(TT-OMe-co-EDTM) electrodes realized a high specific capacitance (190 F/g at 5 mV/s) and recognizable color conversion. This work provides a novel and simple way to synergistically improve electrochromic and energy storage properties and develop thiophene-based conducting polymers for electrochromic energy storage devices.

Self-hybridization structures of BiOBr0.5Cl0.5: An ultra-high capacity anode material for half/full potassium-ion batteries

Potassium-ion batteries (PIBs) are gaining attention among emerging technologies for their cost-effectiveness and the abundance of resources they utilize. Within this context, bismuth oxyhalides (BiOX) have emerged as exceptional candidates for anode materials in PIBs due to their unique structural and superior electrochemical properties. However, challenges such as structural instability and low electronic conductivity remain to be addressed. In this study, a flower-like BiOBr0.5Cl0.5/rGO composite anode material was synthesized, demonstrating outstanding K+ storage performance. The self-hybridized structure enhances ion adsorption and diffusion, which in turn improves charge and discharge efficiency as well as long-term stability. In situ X-ray diffraction (XRD) tests confirmed the gradual release and alloying potassium storage mechanism of Bi metal, which occurs through the intermediate KxBiOBr0.5Cl0.5 phase within the BiOBr0.5Cl0.5 anode. This composite exhibited a high specific capacity of 246.4 mAh/g at 50 A/g and maintained excellent capacity retention after 2400 cycles at 5 A/g. Additionally, in full battery tests, it showed good rate performance and long cycle life, maintaining a discharge specific capacity of 119.6 mAh/g at a high current density of 10 A/g. Comprehensive characterizations revealed insights into the structural, electrochemical, and kinetic properties, advancing high-performance PIBs.

Structurally integrated Ti3C2Tx MXene/cotton fabric electrodes for supercapacitor applications

This study investigates the electrochemical performance of Ti3C2Tx MXene-coated cotton fabric electrodes for supercapacitor applications. The sediment and supernatant parts of synthesized Ti3C2Tx MXene were applied onto cotton substrates through a drop-casting technique at various concentrations to explore the influence of MXene dispersion density on the structural, morphological, and electrochemical properties of the fabric electrodes. Findings indicate that the lower-concentration dispersions not only improve the structural integrity of the coatings but also enhance their electrochemical functionality. The fabric electrodes fabricated from MXene supernatant exhibited significantly lower electrical resistance (7.3 Ω sq−1) and higher specific capacitance, reaching 488 F g−1 at a current density of 0.5 A g−1. The study demonstrates the potential of MXene-coated fabrics as adaptable and efficient energy solutions for wearable technologies, highlighting that tuning the concentration and post-synthesis parameters of MXene dispersions can effectively alter their electrochemical properties.

Fast and green synthesis of battery-type nickel-cobalt phosphate (NxCyP) binder-free electrode for supercapattery

Binder-free electrodes are increasingly important in energy storage technologies owing to the direct growth of active material on conducting substrates without binders, providing a shorter conduction channel for rapid electron transport. Various methods have been employed to synthesize binder-free electrodes, but most approaches often prove time-consuming, and some require elevated synthesis temperatures. Herein, a rapid and eco-friendly microwave-hydrothermal method was introduced to fabricate the battery-type nickel–cobalt phosphate (NxCyP) binder-free electrodes for supercapattery. The use of microwave accelerates heating and reduces the activation energy of the reaction, resulting in shorter synthesis time and lower reaction temperature. The NxCyP electrodes were fabricated at different parameters, such as temperature (90–200 °C), time (5–20 min), and Ni:Co precursor ratios (4:0, 3:1, 2:2, 1:3, 0:4). The optimization study was carried out via Design Expert v13 software, and the optimized parameter was the temperature of 123.5 °C, duration of 10.5 min, and Ni:Co of 2:2, namely N2C2P binder-free electrode. The N2C2P electrode exhibited larger flake- and flower-like morphologies, providing more space for electrolyte ion diffusion and a larger surface area for faradaic reactions. Consequently, it demonstrated outstanding electrochemical performance by displaying a high specific capacity (1699.7C/g at 3 mV/s), superior capacity retention, and the lowest resistances than other NxCyP electrodes. As a result, the N2C2P//AC supercapattery was created by merging it with an activated carbon (AC) electrode, showing a superior energy density (213.0 Wh/kg) and high electrochemical stability with 92.9 % retention after 3000 cycles at 10 A/g.

Nitrogen-rich nanoporous carbon with MXene composite for high-performance Zn-ion hybrid capacitors

The zinc-ion hybrid capacitor, as a novel energy storage system with outstanding electrochemical performance, low cost, and high safety, has attracted widespread research attention. In this work, we report a hetero-structured composite material, C2N@MXene, obtained by alternately stacking porous carbon material C2N with MXene nanosheets. Theoretical calculations and a series of exsitu characterizations reveal that the introduction of MXene nanosheets not only exposes more active sites of C2N, but also significantly enhances the conductivity and stability of the overall composite material, thereby achieving excellent electrochemical energy storage performance. Consequently, as a cathode material for zinc-ion hybrid capacitors, C2N @MXene achieves a high specific capacity of 240 mA h/g at 0.1 A/g and exhibits outstanding rate performance from 1 to 20 A/g. And the capacitance retention rate remains as high as 94%, after 10,000 cycles of charge-discharge at a current density of 5 A/g. Moreover, based on the C2N @MXene electrode, flexible zinc ion micro-capacitor with high area-specific capacity of 264 mF/cm2 was fabricated using laser cutting technology. We believe that this work provides new research strategies for developing high-performance zinc-ion hybrid capacitors.

In-situ cladding PEDOT:PSS on V-doped NCA cathodes for optimized interface and high electrochemical performance of Li-ion battery

The LiNi0.8Co0.15Al0.05O2 (NCA) nickel-rich layered cathode material is widely used for Li-ion batteries because of its excellent structural stability and high specific capacity. However, the Li/Ni mixing effect and the generation of interfacial secondary reactions in NCA cathode materials reduce the electrochemical properties of Li-ion batteries. Herein, we report a series of vanadium (V)-doped NCA cathode (VNCA) materials with different amounts of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) polymers in-situ coated on the surface using a liquid-phase method. The introduction of PEDOT:PSS coating not only improves the conductivity of NCA cathode materials but also protects the surface of cathode materials from cracking during the cycle. Electrochemical results show that the PEDOT:PSS (2 wt%) coating possesses high capacity retention rate (83.58%) after 200 cycles at 1 C, which is better than that of the sample without coating (66.7%). The PEDOT:PSS (2 wt%) coated cathode materials also display superior rate performance to VNCA at high magnification. This work provides new methods and theoretical guidance for the development of efficient ternary cathode materials for Li-ion batteries.

Effect of calcination time on modulating the properties of battery type NiMn2O4 intended for supercapacitor applications

In this study, the synthesis of nanostructured NiMn2O4 is achieved through the novel wet-chemical reduction synthesis method, maintained at a constant temperature of 500 °C. Variations in calcination time to 4, 5, and 6 h, with a constant synthesis temperature, result in the formation of NiMn2O4 (NMO) nanostructures (NSs). These NMO-NSs are employed as electroactive materials in the assembly of electrochemical supercapacitors. Electrodes, composed of NMO-NSs calcined for 4 h, at constant temperature of 500 °C, are observed to exhibit a high specific capacitance/capacity of 966.7 F g−1 (579 C g−1) respectively, at a scan rate of 5 mV s−1. Retention of 96 % of the specific capacitance is noted after 5000 cycles of the as optimum electrode (NM-4 h). The significant influence of calcination time on the efficiency of electrochemical supercapacitors is highlighted in this research. An asymmetric supercapacitor device (ASSCs), featuring a wide working potential window of 0–1.6 V and a energy density of 38.9 W h kg−1 at a power density of 5 kW kg−1. As fabricated ASSCs demonstrates high specific capacitance of 109.4 F g−1/175 C g−1 with capacitance retention of 79.9 % over 5000 cycles. The potential of highly porous binary NiMn2O4 NSs as suitable materials for high-performance supercapacitor devices is suggested by the findings.

In-Situ Sulfuration of CoAl Metal-Organic Framework for Enhanced Supercapacitor Properties.

Designing efficient electrode materials is necessary for supercapacitors but remains highly challenging. Herein, cobalt sulfide with crystalline/amorphous heterophase (denoted as Co(Al)S) derived from an Al metal-organic framework was constructed by ion exchange/acid etching and subsequent sulfidation strategy. It was found that rational sulfidation by adjusting the sulfur source concentration to a suitable level was favorable to form a 3D nanosheet-interconnected network architecture with a large specific surface area, which promoted ion/electron transport and charge separation. Benefiting from the features of the unique network structure and heterophase accompanied by aluminum, nitrogen and carbon coordinated in amorphous phase, the optimal Co(Al)S(10) exhibited a high specific capacity (1791.8 C g-1 at 1 A g-1), an outstanding rate capability and an excellent cycling stability. Furthermore, the as-assembled Co(Al)S//AC device afforded an energy density of 72.3 Wh kg-1 at a power density of 750 W kg-1, verifying that the Co(Al)S was a promising material for energy storage devices. The developed scheme is expected to promote the application of MOF-derived electrode materials in electrochemical energy storage and conversion fields.

Alkali-etching Bi-MOF to create oxygen-deficient α-Bi2O3 nanobelt as high-capacity Ni-Bi battery anode

Bi2O3 has been recognized as a promising anode of aqueous secondary battery because of the high capacity, but the application is greatly hindered by the poor conductivity and limited actual capacity. Herein, for the first time, one dimensional (1D) α-Bi2O3 nanobelt is fabricated via alkali etching strategy using rod-shaped Bi-MOF (CAU-17) as the self-sacrificial template. Specifically, high-crystalline and oxygen-deficient α-Bi2O3 nanobelt with length and width of 6 μm and 300 nm are identified. The electrochemical results demonstrate the high specific capacity (247 mAh g−1@1 A g−1) and acceptable stability of α-Bi2O3 nanobelt. Such superior capacity is derived from the exposed electrochemical active sites, fast charge transfer and efficient ion diffusion in 1D high-crystalline and oxygen-vacancies enriched structure. The assembled Ni-Bi battery displays high capacity (78.3 mAh g−1) and high energy density of 100.2 Wh kg−1 (at power density of 2829.8 W kg−1). Our work provides rational guidance for architecting 1D high-capacitive electrodes for aqueous rechargeable alkaline battery.

Hybrid TiO2–RGO nanocomposite as high specific capacitance electrode for supercapacitor

This study describes the fabrication of composite electrodes comprising TiO2 and reduced graphene oxide layers using a moderate-temperature hydrothermal method. The morphology, crystalline structure, chemical composition, and optical features of the prepared composites were analyzed by FE-SEM, x-ray diffraction, FTIR, and UV–visible spectroscopy. The cyclic voltammetry (CV) and Nyquist plots were used to assess the electrochemical and impedance responses of the composite electrodes, respectively. The analysis revealed that the incorporation of RGO reduced the TiO2 bandgap to 3.87 eV 3.02 eV and improved the specific capacitance, enhancing the TiO2-RGO electrode’s supercapacitive performance. CV studies highlight that the TiO2-RGO composite has a high specific capacitance of 152 F g−1 at a substantially faster scan rate of 25 mV s−1 in a 1.0 M-KOH dilute electrolyte. These findings confirmed the applicability of the fabricated electrodes as prospective supercapacitor electrodes.

Synergistic effects of multi-dimensionality in an aerogel for lithium-ion battery anodes with an enhanced capacitive contribution

The rational design of anode materials is important when seeking to produce high-performance lithium-ion batteries (LIBs) that offer both a high-power density (P) and a high energy density (ε). In this study, a multi-dimensional aerogel composed of 1-dimensional (1D) and two-dimensional (2D) nanostructures was synthesized. To impart conductivity and dimensional diversity, reduced graphene oxide (rGO) nanoplates were introduced to a 1D Co-S aerogel using a metal coordination-assisted sol–gel method. As the anode material for an LIB, the resulting multi-dimensional rGO@Co-S aerogel with 1.4 wt% GO exhibited outstanding electrochemical performance, with a high specific capacity, high-rate capability, strong cycling stability (84 % at 0.5 A/g after 350 cycles), an excellent P (9,660 W/kg), and a high ε (1,566 Wh/kg). This was attributed to the shorter ion and electron diffusion paths arising from the multi-dimensional structure, coupled with the higher surface area and enhanced capacitive contribution due to the addition of the rGO nanoplates.