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Carbon nitrides with two‐dimensional layered structures and high theoretical capacities are attractive as anode materials for sodium‐ion batteries while their low crystallinity and insufficient structural stability strongly restrict their practical applications. Coupling carbon nitrides with conductive carbon may relieve these issues. However, little is known about the influence of nitrogen (N) configurations on the interactions between carbon and C3N4, which is fundamentally critical for guiding the precise design of advanced C3N4‐related electrodes. Herein, highly crystalline C3N4 (poly (triazine imide), PTI) based all‐carbon composites were developed by molten salt strategy. More importantly, the vital role of pyrrolic‐N for enhancing charge transfer and boosting Na+ storage of C3N4‐based composites, which was confirmed by both theoretical and experimental evidence, was spot‐highlighted for the first time. By elaborately controlling the salt composition, the composite with high pyrrolic‐N and minimized graphitic‐N content was obtained. Profiting from the formation of highly crystalline PTI and electrochemically favorable pyrrolic‐N configurations, the composite delivered an unusual reverse growth and record‐level cycling stability even after 5000 cycles along with high reversible capacity and outstanding full‐cell capacity retention. This work broadens the energy storage applications of C3N4 and provides new prospects for the design of advanced all‐carbon electrodes. The polymerization process of C3N4 and nitrogen configurations of its carbonaceous composite were optimized by binary eutectic salt treatment. Benefiting from the introduction of crystalline C3N4 and high‐content pyrrolic‐N, the composite delivered a high capacity of 221.2 mAh g−1 with a capacity retention of 118.5% at 2 A g−1 over 5000 cycles for Na+ storage.

To meet the growing demand for efficient and sustainable power sources, it is crucial to develop high-performance energy storage systems. Additionally, they should be cost-effective and able to operate without any detrimental environmental side effects. In this study, rice husk-activated carbon (RHAC), which is known for its abundance, low cost, and excellent electrochemical performance, was combined with MnFe2O4 nanostructures to improve the overall capacitance of asymmetric supercapacitors (ASCs) and their energy density. A series of activation and carbonization steps are involved in the fabrication process for RHAC from rice husk. Furthermore, the BET surface area for RHAC was determined to be 980 m2 g−1 and superior porosities (average pore diameter of 7.2 nm) provide abundant active sites for charge storage. Additionally, MnFe2O4 nanostructures were effective pseudocapacitive electrode materials due to their combined Faradic and non-Faradic capacitances. In order to assess the electrochemical performance of ASCs extensively, several characterization techniques were employed, including galvanostatic charge –discharge, cyclic voltammetry, and electrochemical impedance spectroscopy. Comparatively, the ASC demonstrated a maximum specific capacitance of ~420 F/g at a current density of 0.5 A/g. The as-fabricated ASC possesses remarkable electrochemical characteristics, including high specific capacitance, superior rate capability, and long-term cycle stability. The developed asymmetric configuration retained 98% of its capacitance even after 12,000 cycles performed at a current density of 6A/g, demonstrating its stability and reliability for supercapacitors. The present study demonstrates the potential of synergistic combinations of RHAC and MnFe2O4 nanostructures in improving supercapacitor performance, as well as providing a sustainable method of using agricultural waste for energy storage.

In recent years, metal oxide‐based, inexpensive, stable electrodes are being explored as a potent source of high performance, sustainable supercapacitors. Here, the employment of industrial waste red mud as a pseudocapacitive electrode material is reported. Mechanical milling is used to produce uniform red mud nanoparticles, which are rich in hematite (Fe2O3), and lower amounts of other metal oxides. A comprehensive supercapacitive study of the electrode is presented as a function of ball‐milling time up to 15 h. Ten‐hour ball‐milled samples exhibit the highest pseudocapacitive behavior with a specific capacitance value of ≈317 F g−1, at a scan rate of 10 mV s−1 in 6 m aqueous potassium hydroxide electrolyte solution. The modified electrode shows an extraordinary retention of ≈97% after 5000 cycles. A detailed quantitative electrochemical analysis is carried out to understand the charge storage mechanism at the electrode–electrolyte interface. The formation of uniform nanoparticles and increased electrode stability are correlated with the high performance. This work presents two significant benefits for the environment; in energy storage, it shows the production of a stable and efficient supercapacitor electrode, and in waste management with new applications for the treatment of red mud. Herein an industrial waste red mud is successfully utilized as a pseudocapacitive electrode material. A ball‐milling technique is employed to produce hematite (Fe2O3)‐rich uniform, spherical, red mud nanoparticles. The nanoparticle‐modified electrode exhibits a promising charge storage ability with an extraordinary retention of ≈97% of initial capacitance even after 5000 cycles at a higher current of 6 A g−1.

Although advanced anode materials for the lithium‐ion battery have been investigated for decades, a reliable, high‐capacity, and durable material that can enable a fast charge remains elusive. Herein, we report that a metal phosphorous trichalcogenide of MnPS3 (manganese phosphorus trisulfide), endowed with a unique and layered van der Waals structure, is highly beneficial for the fast insertion/extraction of alkali metal ions and can facilitate changes in the buffer volume during cycles with robust structural stability. The few‐layered MnPS3 anodes displayed the desirable specific capacity and excellent rate chargeability owing to their good electronic and ionic conductivities. When assembled as a half‐cell lithium‐ion battery, a high reversible capacity of 380 mA h g−1 was maintained by the MnPS3 after 3000 cycles at a high current density of 4 A g−1, with a capacity retention of close to or above 100%. In full‐cell testing, a reversible capacity of 450 mA h g−1 after 200 cycles was maintained as well. The results of in‐situ TEM revealed that MnPS3 nanoflakes maintained a high structural integrity without exhibiting any pulverization after undergoing large volumetric expansion for the insertion of a large number of lithium ions. Their kinetics of lithium‐ion diffusion, stable structure, and high pseudocapacitance contributed to their comprehensive performance, for example, a high specific capacity, rapid charge–discharge, and long cyclability. MnPS3 is thus an efficient anode for the next generation of batteries with a fast charge/discharge capability. The MnPS3, endowed with a unique van der Waals structure, is highly beneficial for fast ionic insertion/extraction and can facilitate buffering volume changes during cycles with robust structural stability. A desirable reversible capacity was maintained well after long cycles in both half‐ and full‐cell lithium‐ion batteries, which is considered an efficient anode for fast charge/discharge batteries.

The undesired side reactions at electrode/electrolyte interface as well as the irreversible phase evolution during electrochemical cycling significantly affect the cyclic performances of nickel-rich NMCs electrode materials. Electrolyte optimization is an effective approach to suppress such an adverse side reaction, thereby enhancing the electrochemical properties. Herein, a novel boron-based film forming additive, tris(2,2,2-trifluoroethyl) borate (TTFEB), has been introduced to regulate the interphasi al chemistry of LiNi 0.8Mn 0.1Co 0.1O 2 (NMC811) cathode to improve its long-term cyclability and rate properties. The results of multi-model diagnostic study reveal that formation lithium fluoride (LiF)-rich and boron (B) containing cathode electrolyte interphase (CEI) not only stabilizes cathode surface, but also prevents electrolyte decomposition. Moreover, homogenously distributed B containing species serves as a skeleton to form more uniform and denser CEI, reducing the interphasial resistance. Remarkably, the Li/NMC811 cell with the TTFEB additive delivers an exceptional cycling stability with a high-capacity retention of 72.8% after 350 electrochemical cycles at a 1 C current rate, which is significantly higher than that of the cell cycled in the conventional electrolyte (59.7%). These findings provide a feasible pathway for improving the electrochemical performance of Ni-rich NMCs cathode by regulating the interphasial chemistry.

Magnesium hydride (MgH 2 ) is considered as an ideal hydrogen storage material with excellent hydrogen capacity, but the slow kinetics impedes its application. Herein, an efficient additive of V 2 C MXene-anchored PrF 3 nanoparticles (PrF 3 /V 2 C) was synthesized, which presents excellent catalytic effect in improving the reversibility and stability of hydrogen storage in MgH 2 . The initial dehydrogenation temperature of the 5 wt.% PrF 3 /V 2 C-containing MgH 2 (182 °C) is 105 °C lower than that of pure MgH 2 , and 6.5 wt.% hydrogen is rapidly released from 5 wt.% PrF 3 /V 2 C-added MgH 2 sample in 6 min at 240 °C. In addition, 5 wt.% PrF 3 /V 2 C-containing MgH 2 sample possesses outstanding reversible hydrogen storage capability of 6.5 wt.% after 10 cycles of dehydrogenation and hydrogenation. Microstructure analysis shows that the introduction of Pr improves the stability of V-species (V 0 and V 2+ ) and O-species (lattice oxygen (O L ) and vacancy oxygen (O V )) formed during ball milling, promotes the interaction between V-species and O-species, and enhances their reversibility, which contributes to the significant improvement in re/dehydrogenation reversibility and cycling stability of MgH 2 . This study provides effective ideas and strategies for the purpose of designing and fabricating high-efficient catalysts for solid-state hydrogen storage materials.

Two-dimensional (2D) sulfide-based transition metal dichalcogenides (TMDs) have shown their crucial importance in energy storage devices. In this study, the tungsten disulfide (WS2) nanosheets were combined with hydrothermally synthesized cobalt magnesium sulfide (CoMgS) nanocomposite for use as efficient electrodes in supercapattery energy storage devices. The characteristics of the WS2@CoMgS nanocomposite were better than those of the WS2 and CoMgS electrodes. XRD, SEM, and BET analyses were performed on the nanocomposite to examine its structure, morphology, and surface area in depth. In three-electrode assemblies, the composite (WS2@CoMgS) electrode showed a high specific capacity of 874.39 C g−1 or 1457.31 F g−1 at 1.5 A g−1. The supercapattery device (WS2@CoMgS//AC) electrode demonstrated a specific capacity of 325 C g−1 with an exceptional rate capability retention of 91% and columbic efficiency of 92% over 7000 cycles, according to electrochemical studies. Additionally, the high energy storage capacity of the WS2@CoMgS composite electrode was proved by structural and morphological investigations.

The demand for sustainable energy storage has driven advancements in supercapacitors, known for their high-power density and rapid charge cycles. However, challenges like limited energy density and material stability must be addressed for practical applications. In this study, VSe 2 /CuS nanocomposites were synthesized using a simple wet chemical method and investigated as electrode materials for supercapacitors. X-ray diffraction (XRD) analysis confirmed the phase purity of the materials while scanning electron microscopy (SEM) revealed spherical and flake-like morphology. The synergy between VSe 2 ’s high electrical conductivity and CuS’s pseudocapacitive properties enhances charge storage and electrochemical performance. The VSe 2 /CuS electrode exhibited a high specific capacitance of 853.9 F/g at 1 A/g, outperforming individual VSe 2 (395.6 F/g) and CuS (471.6 F/g). The VSe 2 /CuS||AC device demonstrated a specific capacitance of 147.6 F/g, excellent rate capability, and 88.3% capacitance retention over 10,000 cycles at 10 A/g. These findings highlight the potential of VSe 2 /CuS nanocomposites as high-performance electrode materials, advancing the development of next-generation energy storage technologies.

In the present study, self-assembled hierarchical CoMn-LDH, CoMn@CuZnS, and CoMn@CuZnFeS heterostructured composites were synthesized for bifunctional applications. As an electrode for a supercapacitor, CoMn-LDH demonstrated superior areal and specific capacitance of 5.323 F cm−2 (279.49 mAh/g) at 4 mA cm−2, comparable to or even higher than other LDHs. The assembled AC//CoMn-LDH hybrid supercapacitor device further demonstrated better stability with 63% original capacitance over 20,000 cycles. Later, as a catalyst, CoMn-LDH, CoMn@CuZnS, and CoMn@CuZnFeS electrodes revealed better performance, with overpotentials of 340, 350, and 366 and −199, −215, and −222 mV to attain 10 mA cm−2 of current density for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. Moreover, for CoMn-LDH, small Tafel slopes of 102 and 128 mV/dec were noticed for OER and HER with good stability compared to heterostructured electrodes.