High Specific Capacitance Research Articles

4,4'-Hydrazobis(1-methylpyridinium) as a Two-Electron Posolyte Molecule for Aqueous Organic Redox Flow Batteries.

Aqueous organic redox flow batteries (AORFBs) are a safe and sustainable solution for the storage of intermittent renewable energy. While several highly soluble two-electron organic molecule negolytes have been developed for AORFBs, most reported organic posolyte species exchange only one electron. Herein, readily available 4,4'-hydrazobis(1-methylpyridinium) dichloride (HydBPyMeCl) is described as a novel two-electron posolyte molecule for AORFBs. The synthesis of HydBPyMeCl was accomplished by a three-step process, yielding multiple grams of the compound. HydBPyMeCl exhibited a reversible two-electron transfer at high redox potential (+0.64 V vs Ag/AgCl reference electrode, pH = 0). When evaluated at 1 M concentration and low pH (2 M HCl) with V3+/V2+ on the negative side, HydBPyMeCl showed high stability. A capacity retention of 99.997% per cycle (99.980% per day measured over 70 days) was achieved, coupled with a high volumetric specific capacity of 47.1 Ah/L (87.2% of capacity utilization at 80 mA/cm2).

Helium Fusion Relevant Plasma Irradiation of Titanium for Medical Application

Irradiation of titanium with stationary helium plasma with edge fusion relevant plasma parameters was carried out in the PLM-M fusion device. A highly specific area and porous nanostructured surface with a nanostructure size from ~20 to ~200 nm was obtained. Such structures are obtained by processing refractory metals irradiated with plasma to produce structures such as fuzz and cauliflower. After plasma irradiation, titanium samples were processed in a nitrogen gas to obtain titanium nitride on the surface. The resulting surface has a high specific capacity and a low impedance of the double electric layer when testing samples in an electrolyte. Such material characteristics are promising for medical use in the manufacture of pacemaker electrodes.

Effects of Porous Filling and Nanofluids on Heat Transfer in Intel i9 CPU Minichannel Heat Sinks

The miniaturization and high integration of modern electronic devices have intensified thermal management challenges. Therefore, developing efficient heat sinks has become crucial to ensuring the stability and performance of high-performance CPUs. Previous studies have not considered the thermally demanding Intel i9 CPU; the current study targets this processor and explores the advantages of more complex minichannel path designs. In addition, this work investigates the enhanced heat transfer performance by integrating metal foams into microchannels. Using a computational approach, this study evaluates the thermal performance of uni-path, dual-path, and staggered-path (SP) minichannel heat sinks with water, Al2O3, and CuO nanofluids at varying Reynolds numbers. The impact of aluminum foam filling has also been examined. Results confirm that higher Reynolds numbers enhance fluid flow, reduce heat sink temperature, and improve temperature uniformity. Among the configurations, the SP heat sink combined with Al2O3 nanofluid achieves the best trade-off between cooling efficiency and energy consumption. While lower porosity foam and higher nanofluid volume fractions enhance heat transfer, they also increase flow resistance, leading to higher energy consumption. Due to its high specific heat capacity, Al2O3 nanofluid outperforms CuO, with optimal cooling observed at a 3–4% volume fraction. The performance evaluation criterion (PEC) captures the trade-off between heat dissipation and energy efficiency. It shows that the SP model with high-porosity aluminum foam and Al2O3 nanofluid turns out to be the most effective design. This combination maximizes cooling efficiency while minimizing excessive energy costs, demonstrating superior thermal management for high-performance microelectronic devices.

Enhanced electrochemical performance of Na2FeP2O7 cathode material for sodium-ion batteries through composite with Cu3(PO4)2

Abstract Among the various polyanionic cathode materials for sodium-ion batteries, phosphate-based materials have demonstrated excellent electrochemical and thermal properties, thereby attracting considerable attention. Na2FeP2O7 stands out as one of the most stable cathode materials, distinguished by its well-defined pore structure and excellent cycling stability, and exceptional air stability. Nonetheless, due to the electron-blocking effect of the metal atoms, Na2FeP2O7 exhibits poor electronic conductivity. To address this, an appropriate amount of Cu3(PO4)2 is integrating with Na2FeP2O7 to synthesize the Na2FeP2O7@Cu3(PO4)2 (NFPO@CPH) composite material. Benefiting from the excellent electronic properties of Cu3(PO4)2, the composite enhances both electronic conductivity and Na+ ion diffusion capabilities of the material. Consequently, the NFPO@3%CPH electrode material exhibits a high specific capacity (88.1 mAh g−1) and excellent cycling stability, retaining 94% its capacity after 250 cycles at 0.1 C. Furthermore, it maintains excellent electrochemical performance under extreme conditions, such as a high temperature of 60 °C and a high mass loading of 11 mg cm−2. The full battery, when paired with hard carbon, achieves a discharge capacity of 82.2 mAh g−1 at 0.1 C, demonstrating its promise for practical application.

Synthesis and Electrochemical Performance of MnS/PANI/CNT Nanocomposites for Supercapacitor Applications

Abstract Polyaniline (PANI) has become a key material in energy storage and conversion systems because of its high specific capacitance, outstanding flexibility, and affordability. Despite these advantages, PANI's limited stability restricts its potential applications. To address this challenge, PANI is integrated with other active materials, including carbon nanotubes (CNTs) and metal-based compounds. Here, we focused on the synthesis and electrochemical evaluation of MnS/PANI/CNT nanocomposites prepared using a hydrothermal method followed by in situ polymerization, specifically for supercapacitor applications. Electrochemical performance was assessed through cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. In terms of supercapacitor performance, the MnS/PANI/CNT nanocomposite demonstrated a significantly higher specific capacitance (325 F/g) compared to pure MnS 58 F/g), MnS/PANI (126 F/g), and MnS/CNT (140 F/g). The galvanostatic charge-discharge curve confirmed the ideal capacitive behavior of the MnS/PANI/CNT nanocomposite electrodes and MnS/PANI/CNT exhibit capacitive retention of 85% after 1000 cycles. Among these MnS/PANI/CNT electrode exhibits outstanding electrochemical properties, with a notable retention of 81.08% at 10 Ag−1 because Combining MnS nanoparticles with interconnected PANI and CNT provides excellent electronic conductivity and stability. This study provides valuable insights into the development of advanced energy storage materials for next-generation electrochemical devices.

A rice husk-derived SiOx/C composite for effective lithium-sulfur battery separator modification.

Lithium-sulfur (Li-S) batteries offer several advantages including high specific capacity, high energy density, cost-effectiveness, and non-toxicity. However, challenges such as the shuttle effect and low electrical conductivity hinder the reversibility during cycling. Herein, we introduce a sustainable rice husk-derived SiOx/porous carbon composite (S-MRH) for separator modification in high-performance Li-S batteries. The S-MRH composite, synthesized via a salt-assisted method without toxic chemicals, features amorphous polar SiOx and porous carbon working synergistically. SiOx promotes a catalytic effect that suppresses polysulfide dissolution, while porous carbon provides an open conductive network. An S-MRH-coated polypropylene (S-MRH/PP) separator exhibited a high specific capacity of 1507.7 mA h g-1 at 0.1C, which is attributed to improved sulfur utilization. Compared to different separators, the S-MRH/PP separator demonstrated a superior rate performance of 766.5 mA h g-1 at 3C. Even under high sulfur loading and lean electrolyte conditions, S-MRH/PP exhibited good cycling stability with high capacities. This study highlights the potential of biomass-derived materials in Li-S batteries and offers insights into SiOx/C synthesis applicable to various energy storage systems.

Sodiophilic Ag-diamane-Modulated Polypropylene Separators for High-Performance Sodium Metal Anodes

Sodium metal is a promising anode material for sodium metal batteries (SMBs) due to its high theoretical specific capacity and low electrochemical potential. However, its practical implementation is severely limited by dendrite formation, which causes short circuits and safety issues. Here, we introduce a separator modification strategy using Ag nanoparticles decorated with two-dimensional diamane on a commercial polypropylene (PP) substrate (Ag-diamane/PP) to enhance the performance of sodium metal anodes (SMAs). The synergistic effect between the sodiophilic Ag nanoparticles and the diamane network not only accelerates Na⁺ transport through the modified separator but also reduces interfacial resistance. This dendrite-suppression effect was systematically validated using in situ optical microscopy and ex situ scanning electron microscopy. Symmetric Na||Na cells incorporating the Ag-diamane/PP separator exhibit exceptional cycling stability, maintaining more than 3800 h of operation at 2 mA cm−2 with a capacity of 1 mAh cm−2. Furthermore, a full-cell configuration with a Na3V2(PO4)3@C cathode, Ag-diamane/PP separator, and Na metal anode delivers a high reversible capacity of 94.35 mAh g−1 and stable cycling for 270 cycles. This work highlights the Ag-diamane/PP separator as a promising solution for advancing dendrite-free SMBs with long-term cycling stability and high energy density.

Modularized Cathode with Neural Network Topology for High Rate and Fault-Tolerant Lithium-Sulfur Batteries.

Enhancing the redox kinetics of electrodes, achieving synergistic optimization of local energy conversion and overall charge transfer, and overcoming the technical bottleneck of significant performance degradation due to local unit failure in traditional electrode systems are crucial for developing high-rate lithium-sulfur batteries. Here, a modular cathode system (CoB1N3-MR/FNN) with a fully connected cascade neural network topology (FNN) is designed by constructing microreactor modules (CoB1N3-MRs) with embedded nanozymes (Co-B1N3), ordering and efficiently interconnecting them. This system not only enables efficient energy conversion within individual microreactors but also significantly enhances the long-range charge transport efficiency and energy aggregation capacity of the electrodes. Furthermore, CoB1N3-MR/FNN achieves fault tolerance to local damage through its distributed energy storage units and redundant charge transport channels. This synergistically enhanced modular electrode system for energy conversion and charge transport exhibits high specific discharge capacity (0.2 C, 1211 mAh g-1) and excellent rate capability (5 C, 731.26 mAh g-1; 10 C, 471.05 mAh g-1), and shows outstanding electrochemical performances in high sulfur loading, low electrolytes, and flexible pouch batteries (0.2 C, 1165 mAh g-1), fully demonstrating its practical application value.

Prelithiation Strategy for Silicon/Carbon Anodes Using AMPS‐Mediated SEI Stabilization

AbstractSilicon‐carbon (Si/C) materials are promising anode candidates for next‐generation lithium‐ion batteries due to their high theoretical specific capacity and excellent cycling stability. However, Si/C anodes suffer from severe irreversible capacity loss during the first charge‐discharge cycle, stemming from silicon's extreme volumetric expansion (up to 300%) during lithiation, which triggers repeated rupture and reformation of the solid electrolyte interphase (SEI) film, depleting active lithium reserves. To address this, pre‐lithiation is implemented by pressing lithium strips onto the Si/C anode surface to compensate for active lithium and enhance initial Coulombic efficiency. However, overcompensation can cause capacity loss and safety risks. Thus, 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) is introduced as an auxiliary material. AMPS promotes stable SEI formation, reduces its repeated rupture, and consumes excess active lithium during pre‐lithiation. Experimental results show that the AMPS‐treated pre‐lithiated Si/C anode achieves an initial Coulombic efficiency of 91.24% (up from 77.47%) and maintains 83.8% capacity retention after 180 cycles. These findings highlight AMPS's role in improving pre‐lithiation effects and enhancing the electrochemical performance of Si/C anodes.

Pineapple stem‐derived porous carbon for symmetrical supercapacitor: evaluation of the effect of activating agent on physicochemical and capacitive characteristics

AbstractBackgroundOwing to the increasing demand for effective energy storage solutions to promote the transformation towards renewable energy sources, research on the development of electrode materials for supercapacitor devices has significantly increased. In this study, we promote a facile, eco‐friendly and sustainable strategy for fabricating electrode materials from pineapple stem waste for supercapacitors via one‐step chemical activation at high temperature. The pineapple stems were activated using KOH, NaOH and ZnCl2 at molarity level of 0.5 mol L−1, then heated at 800 °C for 3 h under N2 protection to produce pineapple stem‐based activated carbon (PSC).ResultsPSC‐K (activated with KOH) exhibits the highest SBET value of 945 m2 g−1 and Vtot of 0.475 cm3 g−1. To evaluate the electrochemical activity of the supercapacitors, devices were designed with different constructions, i.e. symmetric and asymmetric. The PSC‐K‐based symmetric supercapacitor device exhibits a high specific capacitance of 255 F g−1 at 1 A g−1. Further, PSC‐K also delivered an optimum Ed of 35.45 Wh kg−1 at a Pd of 1.06 kW kg−1, and Ed of 22.63 Wh kg−1 at a Pd of 20.37 kW kg−1.ConclusionThis work provides ubiquitous biomass‐derived active carbon that can be widely used as electrode material in supercapacitors for future prospects. © 2025 Society of Chemical Industry (SCI).

High quality large‐scale nickel‐rich layered oxides precursor co‐precipitation via domain adaptation‐based machine learning

AbstractNickel‐rich layered oxides (LiNixCoyMnzO2, NCM) are among the most promising cathode materials for high‐energy lithium‐ion batteries, offering high specific capacity and output voltage at a relatively low cost. However, industrial‐scale co‐precipitation presents significant challenges, particularly in maintaining particle sphericity, ensuring a stable concentration gradient, and preserving production yield when transitioning from lab‐scale compositions. This study addresses a critical issue in the large‐scale synthesis of nickel‐rich NCM (x = 0.8381): nickel leaching, which compromises particle uniformity and battery performance. To mitigate this, we optimize the reaction process and develop an artificial intelligence‐driven defect prediction system that enhances precursor stability. Our domain adaptation based machine learning model, which accounts for equipment wear and environmental variations, achieves a defect detection accuracy of 97.8% based on machine data and process conditions. By implementing this approach, we successfully scale up NCM precursor production to over 2 tons, achieving 83% capacity retention after 500 cycles at a 1C rate. In addition, the proposed approach demonstrates the formation of a concentration gradient in the composition and a high sphericity of 0.951 (±0.0796). This work provides new insights into the stable mass production of NCM precursors, ensuring both high yield and performance reliability.image

Preparation of V2O5 Composite Cathode Material Based on In Situ Intercalated Polyaniline and Its High-Performance Aqueous Zinc-Ion Battery Applications

With the rapid growth of renewable energy, the need for efficient and stable energy storage systems has become increasingly urgent. Aqueous zinc-ion batteries (AZIBs) can offer high safety, abundant zinc supply, and promising electrochemical properties. However, their performance is limited by poor electronic conductivity, slow Zn2+ diffusion, and structural degradation of conventional cathode materials. To address these issues, an in situ polyaniline (PANI) intercalation strategy for vanadium oxide cathodes is introduced in this paper. The conductive PANI chains play three key roles: (1) expand and stabilize interlayer spacing, (2) enhance electronic conductivity, and (3) provide mechanical support to prevent structural collapse and zinc-dendrite formation. A flower-like PANI-V2O5 hybrid is synthesized via synchronous oxidative polymerization, forming a hierarchical architecture without inert intercalants. The resulting electrode achieves a high specific capacity of 450 mAh·g−1 at 0.1 A·g−1 and retains 96.7% of its capacity after 300 cycles at 1 A·g−1, with excellent rate performance. These findings demonstrate that PANI intercalation enhances ion transport, electronic conductivity, and structural integrity, offering a promising design approach for next-generation AZIBs cathodes.

Laser-Induced Coal-Based Porous Graphene as Anode Toward Advanced Lithium-Ion Battery.

Graphene have been considered as the one of the most promising anode materials for the next generation lithium-ion batteries (LIBs) due to its unique properties compared to that of the commercial available graphite anode. However, the tedious preparation process, high cost and easy aggregation of 2D graphene caused by the strong van der Waals interactions among nanosheets affect the high reversible capacity of graphene for LIBs. Herein, a laser-induced strategy employing bituminous coal as a precursor for the preparation of porous graphene-based materials (LIG-B) is reported. LIG-B exhibits a porous foam-like structure and an enlarged interlayer spacing, which is larger than that of graphene with typical AB stacking. As the anode for LIBs, the LIG-B shows a high specific capacity of 400 mAh g-1 at the current density of 100mA g-1, and up to 95.0% of the initial reversible capacity retention after 900 cycles at 100mA g-1. This result is higher than that of graphene-based materials such as N-doped rGO (200 mAh g-1), N-doped Graphene film (150 mAh g-1), and rGO film (80 mAh g-1). Most importantly, a high capacity of 220 mAh g-1 can be maintained at 2000mA g-1, indicating its superior rate capability. This work provides a low-cost method to synthesize porous graphene-based materials with fast Li+/electronic conductivity for high-performance LIBs.

Graphene Oxide‐Based Fullerenes for Efficient Symmetric Configuration Supercapacitors

ABSTRACTGraphene nanomaterials are anticipated to enhance the specific energy‐power of supercapacitors, providing a substitute to lithium‐ion batteries. Herein, we investigate graphene‐oxide sheet/carbon nanoparticle (GO‐CNP) nanocomposites synthesized by ultrasonication of chemically synthesized GO sheets with CNPs directly derived from the GO sheets. Structural authentication revealed that CNPs act as suitable spacers, isolating the 3D GO network layers up to 3.8 sheets (single‐sheet thickness: ~0.55 nm). The as‐prepared nanocomposites, characterized under a three‐electrode electrochemical system in aqueous solution (1 M KOH), displayed high electrochemical capacitive charge storage (97% at scan rate of 100 mV s−1), very high specific capacitance (250 F g−1 at 0.25 A g−1 and 277 F g−1 at 50 mV s−1), and excellent cyclic retention (85.6% of the initial capacitance after 10 000 cycles). A GO‐sheet/CNP‐based symmetric supercapacitor device delivered excellent specific energy‐power density of 64.8 W h kg−1 and 1372.2 W kg−1, respectively. Consequently, the device could power a white‐emitting LED of 10 W at 2.5 V for 1 min with full brightness against a charging time of 20 s. The outstanding electrochemical properties of the nanocomposites are attributed to the disruption of GO stacking due to the presence of conductive CNPs, which facilitated ionic transport for optimized outcomes.

Competitive Solvation Chemistry Modulated Nonflammable Pseudo Ultralow Concentration Electrolyte Toward High‐Voltage Li Metal Batteries

AbstractLithium metal anodes are considered as optimal choice for high‐energy batteries; however, uncontrollable dendritic growth, low Coulombic efficiency, and safety concerns limit their practical applications. Herein, a concept of pseudo ultralow concentration electrolyte featuring high ion conductivity, high Li+ transference number, nonflammability, and broad electrochemical window is proposed via incorporating a high ratio of fluoroether inert cosolvent into a phosphate‐based active solvent for high‐voltage lithium metal batteries. Intermolecular dipole–dipole interactions between the fluoroether and phosphate trigger a competitive solvation effect among the cosolvent, phosphate, and Li+, which can effectively regulate Li+ solvation structure, thereby weakening the Li+‐phosphate interaction and promoting anionic participation in the solvation sheath. Such enriched Li+‐anion configuration facilitates the preferred decomposition of anions and the formation of highly conductive and mechanically robust solid electrolyte interphase, which induces dense and homogeneous lithium deposition and achieves high Li plating/stripping efficiency. Consequently, a Li||Cu cell with an as‐designed electrolyte obtains a high Coulombic efficiency of 99.1%. Additionally, the Li||NCM622 cell exhibits a high initial specific capacity of >170.8 mAh g−1 over 200 cycles with 99.4% capacity retention. This work presents a novel strategy for designing ultralow‐concentration electrolytes for high‐energy metal batteries.

Development of ZrO2-TiO2 binary nanocomposites for enhanced energy storage in supercapacitors

This study focuses on the development of ZrO₂–TiO₂ binary nanocomposites for use in supercapacitor applications. The functionality of the nanoparticles is examined through Fourier transform infrared spectroscopy, X-ray diffraction while their surface morphology is analyzed using scanning electron microscopy. Electrochemical performance is evaluated using techniques such as Cyclic Voltammetry, Electrochemical Impedance Spectroscopy, and Galvanostatic Charge–Discharge measurements. The ZrO₂/TiO₂ nanocomposite demonstrates a high specific capacitance of 226.5 F g⁻1 at a current density of 0.75 A g⁻1. It also exhibits impressive stability, retaining 86% of its capacitance and almost 100% coulombic efficiency after 4000 cycles. Moreover, the nanocomposite exhibits an impressive power density of 5000 W kg⁻1, demonstrating its capability for rapid energy delivery, which is a critical requirement for high-power applications. Simultaneously, it achieves a high energy density of 125.8 Wh kg⁻1, signifying its ability to store substantial amounts of energy per unit mass. Given these remarkable attributes, the ZrO₂–TiO₂ nanocomposite emerges as a highly promising material for energy storage applications, offering a compelling alternative to conventional electrode materials and paving the way for the development of more efficient, sustainable, and high-performance electrochemical energy storage systems.Graphical abstract

Synergistic Molecular Engineering Strategies for Enhancing Diffusion Kinetics and Interfacial Stability of the δ‐MnO2 Cathode in Aqueous Zinc‐Ion Batteries

ABSTRACTLayered manganese dioxide (δ‐MnO2) is a promising cathode material for aqueous zinc‐ion batteries (AZIBs) due to its high theoretical capacity, high operating voltage, and low cost. However, its practical application faces challenges, such as low electronic conductivity, sluggish diffusion kinetics, and severe dissolution of Mn2+. In this study, we developed a δ‐MnO2 coated with a 2‐methylimidazole (δ‐MnO2@2‐ML) hybrid cathode. Density functional theory (DFT) calculations indicate that 2‐ML can be integrated into δ‐MnO2 through both pre‐intercalation and surface coating, with thermodynamically favorable outcomes. This modification expands the interlayer spacing of δ‐MnO2 and generates Mn–N bonds on the surface, enhancing Zn2+ accommodation and diffusion kinetics as well as stabilizing surface Mn sites. The experimentally prepared δ‐MnO2@2‐ML cathode, as predicted by DFT, features both 2‐ML pre‐intercalation and surface coating, providing more zinc‐ion insertion sites and improved structural stability. Furthermore, X‐ray diffraction shows the expanded interlayer spacing, which effectively buffers local electrostatic interactions, leading to an enhanced Zn2+ diffusion rate. Consequently, the optimized cathode (δ‐MnO2@2‐ML) presents improved electrochemical performance and stability, and the fabricated AZIBs exhibit a high specific capacity (309.5 mAh/g at 0.1 A/g), superior multiplicative performance (137.6 mAh/g at 1 A/g), and impressive capacity retention (80% after 1350 cycles at 1 A/g). These results surpass the performance of most manganese‐based and vanadium‐based cathode materials reported to date. This dual‐modulation strategy, combining interlayer engineering and interface optimization, offers a straightforward and scalable approach, potentially advancing the commercial viability of low‐cost, high‐performance AZIBs.

Synergistic Enhancements of Niobium Metal–Organic Framework/V2CTx Composites with Graphene Quantum Dots for Energy Storage and Hydrogen Evolution

MXenes have gained increasing attention due to their unique advantages, including exceptional electrical conductivity, tunable layer structures, and controllable interfacial chemistry. This study addresses these limitations by incorporating niobium metal–organic frameworks (Nb‐MOF) onto vanadium carbide MXene (V2CTx) surfaces, enhancing energy storage and electrochemical water‐splitting performance. Additionally, graphene quantum dots (GQDs) serve as dopants, significantly increasing the specific surface area and charge storage capacity. The optimized Nb‐MOF/V2CTx@GQDs heterostructure exhibits a low hydrogen evolution reaction (HER) overpotential of 90.54 mV at 10 mA cm−2, with a Tafel slope of 103.45 mV dec−1, indicating enhanced charge transfer kinetics. For energy storage applications, the asymmetric Nb‐MOF/V2CTx@GQDs//AC device achieves a high specific capacity of 320 C g−1 at 2.0 A g−1, an energy density (Ed) of 59 Wh kg−1, and a power density (Pd) of 1800 W kg−1, while maintaining 81.2% capacity retention and 87.5% Coulombic efficiency after 12 000 cycles. These findings demonstrate the synergistic effect of Nb‐MOF and V2CTx, further enhanced by GQDs, establishing the composite as a promising material for next‐generation energy storage and HER.

Litchi-Skin-Like NiMoP2 Microspheres Supported on MOF-Derived Carbon Layer as High Performance Composite Positive Electrode of Asymmetric Supercapacitor.

Developing ideal positive electrodes with excellent performance and structural stability for supercapacitors is crucial in enhancing the application potential. Herein, we successfully fabricate a composite structure of NiMoP2@C on nickel foam (NF) (NMP@C/NF), which is formed by loading a litchi-skin-like morphology NiMoP2 microspheres onto MOF-derived carbon layer with the two-step electrodeposition method. The carbon layer acts as a structurally stable framework, and its synergistic effect with active materials suppresses volume expansion while enhancing electron transport efficiency. Meanwhile, the heterogeneous interface between crystalline/amorphous phases optimizes redox reaction kinetics, and the unique morphology composed of multi-scale components increases the accessible surface area for redox reactions. As a result, the NMP@C/NF obtains a high specific capacitance of 2224.8 F g-1 at 1 A g-1, and the capacitance retention rate is 94.97% after 8000 cycles. The asymmetric supercapacitor (ASC) assembled with NMP@C/NF positive electrode and active carbon negative electrode generates an energy density of 52.52Wh kg-1 at a power density of 784.55W kg-1, and its capacitance retention rate reaches up to 78% after 8000 cycles. This study provides promising pathway for the rational design of high-performance and environmentally friendly positive electrodes for supercapacitors.

Boosting Initial Coulombic Efficiency in Li-Rich Mn-based Cathodes by Tuning Orbital Hybridization.

Li-rich manganese-based oxides (LRMO) are promising cathode materials for next-generation lithium-ion batteries due to their high-capacity and low-cost merits. However, the low initial coulombic efficiency (ICE) and irreversible oxygen release of LRMO severely hinder their commercialization processes. Here, we employ glyoxal treatment to modulate the hybridization between transition metal (TM) 3d and oxygen (O) 2p orbitals in LRMO. This approach is found to reduce the Co/Mn t2g-O 2p hybridization in LRMO while simultaneously activating the Co2+/Co3+ redox below the Fermi level. Our findings demonstrate that tuning TM 3d-O 2p orbital hybridization can be a viable approach to improve the ICE of LMRO. Specifically, the ICE of LRMO can be elevated from 85.3 % to 102.5 %, and a high specific capacity of 291.2 mAh g-1 can be achieved at 0.1 C. Moreover, the treated LRMO cathodes exhibit significantly enhanced capacity retention.