Field Of Supercapacitors Research Articles

Three-dimensional phloretin-functionalized graphene aerogel for high-performance supercapacitors and phase change materials

Abstract Graphene aerogels have attracted considerable attention owing to their significantly higher electrical and thermal conductivity compared with conventional materials. To further enhance the surface functionality of graphene aerogels, we prepared three-dimensional multi-functional aerogels via hydrothermal treatment and freeze-drying using natural green organic small-molecule compound phloretin and graphene oxide. This aerogel has excellent electrochemical properties, with a specific capacitance as high as 433 F/g (at a current density of 1 A/g). In addition, symmetrical supercapacitors assembled with this electrode material exhibit excellent energy storage performance with an energy density of 13.33 W h/kg, power density of 399.9 W/kg and capacitance retention rate of 88% after 10,000 cycles. Furthermore, a phase change material prepared using the aerogel and pure paraffin wax shows significantly higher energy conversion efficiency than sole paraffin wax and exhibits good thermal stability. Overall, owing to its unique physicochemical properties and environmental friendliness, the prepared multi-functional aerogel has good application prospects in the fields of supercapacitors and thermal management.

N-doped porous carbon derived from different lignocellulosic biomass models for high-performance supercapacitors: the role of lignin, cellulose and hemicellulose.

Biomass-derived porous carbon (PC) has been widely studied in the field of supercapacitors due to its low cost, sustainability and developed pore structure, but how to screen the precursors of high-performance PC is still a major difficulty. Herein, six lignocellulosic biomass models based on different compositions were innovatively constructed and prepared into high-performance PC by a synergistic activation-doping strategy. The results show that the synergistic activation-doping strategy has a certain universality for biomass models. Meanwhile, cellulose and hemicellulose mainly contribute to the formation of micropores, resulting in high specific surface area (SSA), specific capacitance and energy density. While lignin provides some micropores and most mesopores for PC, which enables PC to exhibit excellent rate and cycling performance. Specifically, the MF prepared from the biomass model constructed based on wheat bran has the optimized specific capacitance (474Fg-1 at 1 A g-1), due to its largest SSA (2773m2g-1) and high proportion of micropores (76.6%). At 5 A g-1, the coulombic efficiency during 5000cycles is maintained at 98.8-99.4%, and the final capacity retention is 95.89%. Impressively, an aqueous symmetric supercapacitor based on MF assembled in 1M Na2SO4 electrolyte delivers an energy density of 27.66Whkg-1 at a power density of 82.03Wkg-1. This study provides a reference for the precursor screening of high-performance PC at the composition level, and also contributes an operational idea for PC performance regulation.

Research advances of metal fluoride for energy conversion and storage

AbstractIn recent years, renewable energy sources, which aim to replace rapidly depleting fossil fuels, face challenges due to limited energy storage and conversion technologies. To enhance energy storage and conversion efficiency, extensive research has been conducted in the academic community on numerous potential materials. Among these materials, metal fluorides have attracted significant attention due to their ionic metal–fluorine bonds and tunable electronic structures, attributed to the highest electronegativity of fluorine in their chemical composition. This makes them promising candidates for future electrochemical applications in various fields. However, metal fluorides encounter various challenges in different application directions. Therefore, we comprehensively review the applications of metal fluorides in the field of energy storage and conversion, aiming to deepen our understanding of their exhibited characteristics in different electrochemical processes. In this paper, we summarize the difficulties and improvement methods encountered in different types of battery applications and several typical electrode optimization strategies in the field of supercapacitors. In the field of water electrolysis, we focus on surface reconstruction and the critical role of fluorine, demonstrating the catalytic performance of metal fluorides from the perspectives of reconstruction mechanism and process analysis. Finally, we provide a summary and outlook for this field, aiming to offer guidance for future breakthroughs in the energy storage and conversion applications of metal fluorides.

Fuel-Dependent combustion synthesis of CeCrO3 nanomaterials: Morphological control and its impact on electrochemical properties and device applications

Perovskites exhibiting pseudocapacitance are among the leading energy storage materials as supercapacitors. The cations in perovskites significantly affect storage due to their involvement in redox reactions. CeCrO3 (CCO), a challenging-to-synthesis perovskite, has not yet been investigated for its electrochemical performance. The electrochemical properties of a material heavily depend on each step of the synthesis method. The combustion synthesis of CCO is carried out with different fuels, such as glycine (G), citric acid (C), and sucrose (S), resulting in samples CCO–G, CCO–C, and CCO–S, respectively. This makes combustion with different fuels yield products with peculiar properties and variations in morphology. Consequently, all CCO samples using different fuels exhibit noticeable differences in their electrochemical properties. A systematic investigation is conducted to understand the suitability of CCO for supercapacitor applications. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques are performed in a 2 M KOH electrolyte. CCO–G exhibits the highest specific capacity among the samples, achieving the specific capacity of 461 C g-1 at 1 A g-1 current density. It maintains good cyclic stability of 72.98 % even after 10,000 cycles at the current density of 10 A g-1. To explore its practical applicability, a hybrid supercapacitor device is fabricated with activated carbon (AC) AC@Ni-foam as the negative electrode and CCO–G@Ni-foam as the positive electrode in a 2 M KOH electrolyte. This device demonstrates a specific capacity of 204.80 C g-1 at 1 A g-1 current density. The maximum specific energy, the device achieved is 36.92 Wh kg-1 at 1 A g-1 current density, and the maximal specific power is 7.91 kW kg-1 at current density of 20 A g-1. These significant values emphasize the applicability of this novel material in the field of supercapacitors, paving the way for advanced energy solutions.

Controllable synthesis of N-rich defective carbon materials for aqueous supercapacitors: Towards a trade-off between gravimetric and volumetric capacitance

The conversion of biomass into porous carbon with high specific surface area (SSA) could be applied in the field of supercapacitors, which realised the resourceful use of biomass. However, the increase in SSA provided carbon materials with lower volumetric capacitance, thereby limiting the development of carbon-based supercapacitors (SCs). To trade off gravimetric and volumetric capacitance, the active nitrogen doping strategy was an effective route. Herein, nitrogen-rich micro-mesoporous composite carbon materials were synthesised from forestry waste (bamboo) as raw material, with guanidine carbonate as N-rich agent and KHCO3 as green activator. The N-rich agent exhibited multiple roles in the co-pyrolysis process, which were pore creation and heteroatom doping. In this paper, the correlation between the type of N-rich agent, the addition amount and the pre‑carbonization temperature and the electrochemical properties of carbon materials were investigated. Due to the multifunctionality of guanidine carbonate, the carbon material exhibited excellent SSA (1469.14 cm2/g), outstanding microporous structure, and abundant reactive N sites, which facilitated the efficient transport of electrolyte ions. Among them, the best carbon material (BC/CN-400-1) showed a high gravimetric capacitance of 376.25 F/g, demonstrating a volumetric capacitance of 355.54 F/cm3 at the same time. In addition, the aqueous symmetrical supercapacitor (BCN//BCN) displayed remarkable cycling stability (94.35 %). The BCN//BCN achieved an energy density of 15.64 Wh/kg at a power density of 75 W/kg. In summary, this study proposed a controllable N-atom doping technique, which offered a feasible route for the synthesis of N-doped hierarchical nanomaterials. Meanwhile, using forestry wastes as raw materials for the preparation of high-performance carbon-based supercapacitors facilitated resources utilization of biomass and sustainable development, providing a reference for the fabrication of N-rich biomass-derived carbon materials.

Research Progress and Challenges of Carbon/MXene Composites for Supercapacitors

Carbon materials/MXenes composite materials have gained widespread attention in the field of supercapacitors due to their excellent electrochemical performance. Carbon materials are considered ideal electrode materials for supercapacitors due to their high specific surface area, good conductivity, and outstanding electrochemical stability. MXenes, as a novel two-dimensional material, exhibit prominent conductivity, mechanical properties, and ionic conductivity, thereby showing great potential for applications in energy storage devices. The combination of carbon materials and MXenes is expected to fully leverage the advantages of both, optimizing electrode conductivity, enhancing the energy density and power density, and improving the charge–discharge performance. This article reviews the key research progress of carbon/MXenes composite materials in supercapacitors in recent years, including their synthesis methods, structural tuning, and improvements in their electrochemical performance. Finally, the article looks forward to future research directions and proposes potential strategies to enhance the overall performance of the composite materials and achieve large-scale applications. By addressing the existing challenges, carbon/MXenes composite materials are anticipated to achieve higher energy and power outputs for the supercapacitor field in the future, providing strong support for the development of new energy storage technologies such as electric vehicles and wearable devices.

A multifunctional platform based on ZIF-67 templated NiCo-LDH and Fe3O4 hollow spheres for photocatalytic CO2 conversion and supercapacitors

This work presented a series of hybrid materials F@P-LDHs exhibiting the core-shell structure with PPy as the interface modifier, explored as dual-functional materials for studying photocatalytic reduction of CO2 and electrochemical behaviors. F@P-LDHs served as photocatalysts, effectively convert CO2 into CO without using any sacrificial agents and photosensitizers via the gas-solid mode under the visible light irradiation. The generation rate of CO was as high as 10.32 μmol g−1h−1, which was 5.4 and 6.4 times higher than the original Fe3O4@PPy and NiCo-LDH. The well performance might be ascribed to the generation of type Z heterojunction with the interface modifier PPy, jointly accelerating the separation and migration of photo-generated charge carriers between Fe3O4@PPy and NiCo-LDH. Besides, F@P-LDHs were also developed as supercapacitors, and their electrochemical behaviors were investigated. Their good electrochemical performances were attributed to the synergistic effect among hollow Fe3O4 microspheres, polypyrrole and NiCo-LDH. Therefore, as dual-functional materials, the hybrid materials have great potential in the field of CO2 conversion and supercapacitors.

Graphene, graphene oxide or modified graphene in polyaniline based nanocomposites—features and technical highlights

Polyaniline is a remarkable conjugated polymer having valuable structural and physical characteristics. Nevertheless, polyaniline has poor solubility and structural durability which had limited its practical utilization. Consequently, polyaniline has been reinforced with carbonaceous and inorganic nanoparticles to enhance its processability and physical properties, such as electrical/thermal conductivity and thermal/mechanical stability. Accordingly, polyaniline has been applied as a valuable matrix material to form nanocomposites with graphene which is a one atom thick nanosheet of hexagonally arranged carbon atoms. Subsequently, graphene as well as modified graphene forms have been utilized as important nanoadditives for the polyaniline matrix. This state-of-the-art review article has been designed to investigate the fabrication, characteristics, and applications of the polyaniline and graphene/modified graphene based nanomaterials. Potential enhancements in the physical characteristics of the pristine polyaniline upon graphene reinforcement seemed to be reliant upon the matrix-nanofiller interactions, interface formation, and synergetic effects between polyaniline-graphene. Subsequently, practical aspects of the polyaniline/graphene nanocomposites have been discussed regarding their applications in the fields of solar cells, supercapacitors, and sensors. According to the literature analysis, dye sensitized solar cell based on polyaniline/graphene and polyaniline/graphene oxide exhibited superior power conversion efficiencies ∼2.0-7.6 % and open circuit voltage ∼500-800 mV. Supercapacitor electrodes based on polyaniline/graphene oxide and polyaniline/reduced graphene oxide showed significantly high values of specific capacitance and capacitance retention of ∼1100-1900 Fg−1 and ∼80-98 %, respectively, during >5000-6000 cycles. Besides, the polyaniline/graphene oxide depicted superior sensitivity and response time for gas sensors (∼20 % and 50 s, respectively) and humidity sensors (>90 % and 4-7 s, respectively) and low detection limits for biosensors.

Research and Application Progress of Aerogel Materials in the Field of Batteries and Supercapacitors

Aerogels, characterized by their exceptional porosity, vast specific surface areas, minimal density, and unparalleled thermal insulation capabilities, have become a focal point of attention in the energy sector over the past decade, particularly in the realms of batteries and supercapacitors. This comprehensive review delves into aerogels and their preparation methods, while reviewing their recent applications in batteries and supercapacitors. It delves deeply into the research and development progress, as well as the application advancements of aerogel materials in separators, electrolytes, and electrodes. Furthermore, this article highlights that the research on aerogels still faces some challenges, such as steep costs, sophisticated production steps, and relatively weak overall mechanical strength. Therefore, in the future, it is necessary to further strengthen the fundamental research and technological innovation of aerogel materials, and promote their industrialization process and wide application in the field of energy storage, particularly in the areas of batteries and supercapacitors.

NiMoO4@NiSe2 microspheres as electrode materials for high-performance supercapacitor

Supercapacitors as novel sustainable energy conversion systems have been a hot spot owing to their high specific capacitance and excellent cycle stabilities. However, the poor electron conductivity limits their further applications. Herein, we synthesize NiMoO4@NiSe2 samples by a controllable hydrothermal route. The heterogeneous structure consists of high conductive nanosheets and high capacitive particles. It can slow down the collapse of electrode materials and enhance the conductivity of material. It also facilitates ion diffusion and faradaic redox reaction, thereby improves the electrochemical performance. The as-synthesized electrode presents a specific capacity of 1193 C g-1 at 1 A g-1 and maintains 82.9 % of the initial capacitance after 10,000 times cycles. A hybrid capacitor is constructed using the composites as the electrode material. It possesses a capacitance of 101 C g-1 at 1 A g-1 and 85.8 % of the retention rate after 10,000 times charging-discharging. This impressive performance of composite could be attributed to their mesoporous surface with high specific surface area (48 m2g-1). Moreover, the supercapacitor shows excellent flexibility after folding, exhibiting a wide application prospect in the field of supercapacitors.

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.

Hollow-structured and nano-flower shaped high entropy layer double hydroxide for superiority specific capacitance and rate capability of supercapacitor

High entropy hydroxide as electrode materials has been widely studied in the field of supercapacitors, but due to the limited active site and poor conductivity, it usually shows poor specific capacity and magnification performance, which seriously limit its development in the field of supercapacitors. In this work, a hollow-structured and nano-flower shaped high entropy layer double hydroxide was synthesized by the double template method combined with nano-etching to achieve superiority specific capacitance and rate capability of supercapacitor. The experimental and theoretical results indicate that the specific capacitance of this novel electrode material is as high as 1820.1 F·g−1. In particular, after the current density was increased by 40 times, the specific capacitance can reach 1140.2 F·g−1, and its electrochemical performance is higher than most of high entropy electrode materials reported so far. More importantly, the S-HE-LDH//AC HSC was constructed with the material as the electrode. It has an energy density of 74.2 Wh·kg−1 at 475 W·kg−1 power density. After 5000 cycles, the specific capacitance of the HSC device can still maintain 90.8 % of its initial value. These results indicate that the electrochemical properties of LDHs can be effectively improved by the combination of microstructure adjustment and electronic structure optimization.

Bimetallic ions modified 2‐methylimidazolium functionalized polypyrrole/graphene oxide for the improved supercapacitor

AbstractThin films with two‐dimensional (2D) nanostructures possess good environmental stability, thinner thickness and large surface area, which are widely used as a promising modified electrode material in the field of energy storage, supercapacitors, electrochemical sensors and biosensors. Herein, unique bimetallic ions modified polypyrrole/graphene oxide (PPy/GO) nanosheets, including Co2+‐Zr4+/(2‐MeIm)x@PPy/GO and Co2+‐Run+/(2‐MeIm)x@PPy/GO (n = 0, 4), are prepared by using 2‐methylimidazolium (2‐MeIm) as the linkers between PPy/GO and metal ions. The obtained electrodes constructed by Co2+‐Run+/(2‐MeIm)x@PPy/GO (n = 0, 4) and Co2+‐Zr4+/(2‐MeIm)x@PPy/GO exhibit improved capacitor electrochemical properties due to the reversible redox reaction, the large specific surface area and the high theoretical specific capacitance value of the metal ions compared to the unmodified PPy/GO. Especially, the specific capacitance value of Co2+‐Run+/(2‐MeIm)x@PPy/GO (n = 0, 4) electrode reaches 321.78 F g−1 at a current density of 1 A g−1 and the capacitance retention rate is achieved to 100% in the long cycle charge/discharge test after 10 000 cycles (10 A g−1). It will provide a practical experience for the design and preparation of supercapacitors based on bimetallic ions modified PPy/GO.

Renewable synthesis of MoO3 nanosheets via low temperature phase transition for supercapacitor application

2D transition metal oxides have created revolution in the field of supercapacitors due to their fabulous electrochemical performance and stability. Molybdenum trioxides (MoO3) are one of the most prominent solid-state materials employed in energy storage applications. In this present work, we report a non-laborious physical vapor deposition (PVD) and ultrasonic extraction (USE) followed by vacuum assisted solvothermal treatment (VST) route (DEST), to produce 2D MoO3 nanosheets, without any complex equipment requirements. Phase transition in MoO3 is often achieved at very high temperatures by other reported works. But our well-thought-out, robust approach led to a phase transition from one phase to another phase, for e.g., hexagonal (h-MoO3) to orthorhombic (α-MoO3) structure at very low temperature (90 °C), using a green solvent (H2O) and renewable energy. This was achieved by implementing the concept of oxygen vacancy defects and solvolysis. The synthesized 2D nanomaterials were investigated for electrochemical performance as supercapacitor electrode materials. The α-MoO3 electrode material has shown supreme capacitance (256 Fg−1) than its counterpart h-MoO3 and mixed phases (h and α) of MoO3 (< 50 Fg−1). Thus, this work opens up a new possibility to synthesize electrocapacitive 2D MoO3 nanosheets in an eco-friendly and energy efficient way; hence can contribute in renewable circular economy.

Machine learning prediction of supercapacitor performance of N-doped biochar from biomass wastes based on N-containing groups, element compositions, and pore structures

N-doped biochar has great potential for development in the field of supercapacitors. In this study, Random Forest and Extreme Gradient Boosting models are used to predict the specific capacitance of N-doped biochar. The prediction is based on several features, including pore structure parameters, element composition, N-containing group of N-doped biochar, and electrochemical testing characteristics. Shapley additive explanations and partial dependency plots are used to explore the impact of the features on specific capacitance. Results show that both the Random Forest and the Extreme Gradient Boosting models exhibited excellent prediction performance, with R2 of 0.95 and 0.96, respectively. N-6 contributes more to the higher specific capacitance among the three N-containing groups. According to the partial dependency plots, when the specific surface area, pore size, and degree of graphitization are around 2200 m2/g, 4 nm, and 1, respectively, the specific capacitance of N-doped biochar is about 303 F/g at 1 A/g. In addition, a procedure for predicting the specific capacitance of N-doped biochar is developed based on the PySimpleGUI library and the Extreme Gradient Boosting model. This study provides a reference for the preparation of high specific capacitance of N-doped biochar.

Eco-friendly synthesis of indole-4-hydroxy-chromen-2-ones using green zinc oxide nanocatalyst and its assessment of anti-cancer studies against A549 cells

Zinc oxide (ZnO) nanoparticles have significant attention in the field of photocatalyst, super capacitor, battery and biomedicine due to their versatile potential and diverse applications. In the present study, ZnO was synthesized using Celastruspaniulatus leaf extract as a green fuel through combustion method. The morphological and structural studies of ZnO were characterized using XRD, FTIR, UV–Vis, SEM and TEM analysis. The PXRD pattern of ZnO as shown diffraction peaks of ZnO planes (100), (002), (102), (110), (103) and (112) are hexagonal Wurtzite ZnO structure. ZnO is formed in a discrete irregular hexagonal shape was confirmed by SEM analysis. The application of ZnO is achieved for the synthesis of (4-hydroxy3-(1H-indol-3-yl)-phenyl-methyl-chromen-2-one) and its derivatives via Knoevenagel/Michael addition reaction. All synthesized compounds showed good yield and are characterized using 1H NMR, 13C NMR and ESI-MS spectral studies. The reusability of the ZnO catalyst is tested and documented. Some of the synthesized chromenone compounds show promising anticancer activity against A549 cells with less concentration.

High-performance biomass tar-based nanofibers with CoNi nanosheets prepared by electrospinning for supercapacitor electrode material

Biomass-based nanofibers prepared by electrospinning have broad prospects in the field of supercapacitors. In this work, biomass tar-based carbon nanofibers (CNFs) are prepared by electrospinning technology, and the CoNi nanosheets are grown on the surface of CNFs. The obtained electrode materials have a three-dimensional open petal-like nanofiber structure, and the results of the electrochemical performances show that the CoNi@CNF-1 has a specific capacitance of 474.4F g−1 at 0.5 A g−1, an energy density of 65.9 Wh kg−1 and a power density of 250 W kg−1. After 5000 charge-discharge cycles, the CoNi@CNF-1 still maintains 95.4 % of its original capacitance in the three-electrode system. This work provides an important reference for the effective treatment of biomass tar and its application in the field of electrochemical energy storage.

The synthesis of hollow carbon nanospheres from potato starch and the application in supercapacitor

The synthesis of high-valued carbon nanomaterials from biomass has always been a hot topic. The work reports the preparation of hollow carbon nanospheres (HCNs) from potato starch with one-step carbonization, in which self-made MgO powder is utilized as the template. In this study, an attempt was made to change carbonization temperature to control HCNs in diameter, wall thickness and pore distribution. Results show that the sample obtained at 800 °C (HCN-800) has a thinner wall thickness (about 12.1 nm), smaller and more uniform diameter (average diameter of 46.2 nm), as well as possesses a high specific surface area (619.53 m2 g−1) and the largest pore volume (2.8994 cm3 g−1). An application in supercapacitor has been verified for the HCNs in the work. In the three-electrode system, the HCN-800 exhibits excellent electrochemical performance, such as superior specific capacitance (324.8 F g−1 at 0.5 A g−1), high rate performance (215.7 F g−1 at 50 A g−1) and outstanding cycling stability (92.83 % capacitance retention after 10,000 cycles). Moreover, an assembled symmetric supercapacitor shows an energy density of 11.1 Wh kg−1 at a power density of 427 W kg−1, far exceeding that of previously reported carbon electrode materials. In short, the work provides a novel way to synthesize high-value-added HCNs from cheap biomass precursors, which have potential applications in the field of supercapacitors and other energy storage devices.

Copper/Cobalt based metal phosphide composites as positive material for supercapacitors

The excellent conductivity and fast redox kinetics of transition metal phosphides (TMPs) have made them a suitable electrode material for energy storage in the field of supercapacitors (SCs). In this paper, coral-like Cu3P/CoP heterostructures have been obtained by a simple solid-phase grinding and subsequent phosphating method. Importantly, the Cu3P/CoP heterostructure can provide sufficient charge to further accelerate the Faraday kinetics of the redox reaction due to its ability to generate an internal electric field, thus improving its electrochemical performance. Through density-functional theory (DFT) computations, it is demonstrated that the heterostructures of Cu3P/CoP enhances the metal-like conductivity of the composite, exhibiting more electron-occupied states around the Fermi energy level and improves the charge-transfer efficiency of the heterostructure. The results show that the Cu3P/CoP-1 composite with a 1:1 Cu/Co molar ratio has the best electrochemical performance. At 1 A·g−1, it exhibits an excellent specific capacitance of 804.3 F·g−1, and when the current density is increased to 10 A·g−1, it retains its capacitance for 92.8% of 10,000 cycles. Furthermore, with a power density of 806.23 W·kg−1, an asymmetric supercapacitor (ASC) built using Cu3P/CoP-1 as the cathode may produce an energy density of 37.40 Wh·kg−1. The reasonable design of heterostructures of bimetallic TMPs in this research offers a workable plan for exploring electrode materials with excellent capacitive properties.

Facile Preparation of MXene Decorated PANI/Lignosulfonate Nanocomposite Film Electrodes for Electrochemical Supercapacitors

AbstractMXenes are a large family of two‐dimensional transition‐metal carbides, nitrides, and carbonitrides with large surface area and metal conductivity. They have not been widely used as electrodes in the field of supercapacitors because of their low specific capacity, poor chemical stability, and tendency towards self‐stacking. Herein, a three‐component nanocomposite film electrode has been successfully achieved, consisting of MXene nanosheets, polyaniline (PANI), and lignosulfonate (LGS). The PANI‐LGS nanocomposite was prepared through the oxidative polymerization of PANI in the presence of LGS, and then MXene decorated PANI/LGS (labeled as MPL) nanocomposite films were facilely self‐assembled via a vacuum‐assisted filtration by using the dispersion. Compared with pure PANI and PANI‐LGS, the MPL nanocomposite film electrode possesses better conductivity, showing a high specific capacitance of 559 F/g at a scan rate of 5 mV/s and a capacity retention rate of 92.2 % after 1000 cycles at a current density of 10 A/g. This study demonstrates that the doping of LGS and MXene can significantly improve the electrochemical performance of PANI‐based composite materials. Thus, the convenient preparation and excellent electrochemical performance of MPL show great potentials in the application of high‐performance electrodes for supercapacitors.