Energy Storage Applications Research Articles

Progress and Perspective of High‐Entropy Strategy Applied in Layered Transition Metal Oxide Cathode Materials for High‐Energy and Long Cycle Life Sodium‐Ion Batteries

AbstractLayered transition metal oxide (LTMO) cathode materials of sodium‐ion batteries (SIBs) have shown great potential in large‐scale energy storage applications owing to their distinctive periodic layered structure and 2D ion diffusion channels. However, several challenges have hindered their widespread application, including phase transition complexities, interface instability, and susceptibility to air exposure. Fortunately, an impactful solution has emerged in the form of a high‐entropy doping strategy employed in energy storage research. Through the implementation of high‐entropy doping, LTMOs can overcome the aforementioned limitations, thereby elevating LTMO materials to a highly competitive and attractive option for next‐generation cathodes of SIBs. Thus, a comprehensive overview of the origins, definition, and characteristics of high‐entropy doping is provided. Additionally, the challenges associated with LTMOs in SIBs are explored, and discussed various modification methods to address these challenges. This review places significant emphasis on conducting a thorough analysis of the research advancements about high‐entropy LTMOs utilized in SIBs. Furthermore, a meticulous assessment of the future development trajectory is undertaken, heralding valuable research insights for the design and synthesis of advanced energy storage materials.

Lignin Nanofiber Flexible Carbon Aerogels for Self-Standing Supercapacitors.

Renewable feedstocks are sought for clean technology applications, including energy storage applications. In this study, LignoForce™ lignin, a biobased aromatic polymer commercially isolated from wood, was fractioned into two parts using acetone, and the resulting lignin fractions had distinct thermo-rheological behavior. These two fractionated lignins were combined in various ratios and transformed into nanofibers by electrospinning. Subsequently, electrospun fiber materials were disrupted by agitating the mats in water, and the materials were transformed into ultralight 3D aerogels through lyophilization and post-process controlled heating. Using only this combination of two fractions, the morphology of lignin nanofibers was tailored by heat treatment, resulting in lignin aerogels with high flexibility and significant shape recovery properties. Various microscale structures of lignin fibers impacted the resulting physical properties of the elastic aerogel materials, such as resilience, compressive strength, and electrical conductivity for the corresponding carbonized samples. By exploiting lignin's sensitivity to heat and tailoring the thermal properties of the lignin through fractionation, the work provided an interesting path to form robust lignin-derived functional materials without any toxic chemical additives and significant ability to serve as free-standing electrodes with specific capacitance values better than some graphene-based supercapacitors.

Changes in electronic structure within NiSx (0.60 < x < 1.53) compound series

In this article, changes in electronic properties of NiSx series of films with different sulfur content (x = S/Ni) are studied using X-ray (XPS) and ultra-violet (UPS) photoelectron spectroscopy techniques. NiSx (0.60 < x < 1.53) films are synthesized on native oxide of Si(111) substrates via reactive deposition of Ni and S in an ultra-high vacuum chamber by varying the sulfur pressures and substrate temperatures. The binding energy (BE) of Ni2p3/2 core level, the separation between the Ni2p3/2 main peaks and satellite peaks, and the Ni3d valence band binding energies are all found to vary nearly linearly with the sulfur content in NiSx series of compounds, suggesting a direct dependence of Ni electronic charge on the sulfur content. The shift of the Ni3d and S3p states (to higher and lower BE, respectively) with an increase in the S content provides experimental confirmation of the theoretical prediction previously reported (Wen et al., 2020) [1]. All NiSx films showed density of states (DOS) at the Fermi level, indicating their metallic nature. The Ni2p3/2 binding energy shift of NiSx films are much smaller than that of oxide-based compounds, confirming the significantly more covalent nature of the sulfides. NiSx film grown on Si (111) substrate showed nickel silicide interface formation. This study provides information on the growth and trends in the electronic properties of NiSx relevant for their applications in catalysis, energy storage, and electronic devices.

Eco-friendly high microporosity low temperature plasma exposed activated carbon from coconut shell for nano hybrid supercapacitors

Abstract This study looked at the structural, chemical, and electrochemical properties of coconut shell activated carbon (CSAC) before and after plasma treatment. Structural analysis using x-ray diffraction (XRD) demonstrated that plasma treatment improves graphitic structure by plans at (002) and (101) for higher angles. Chemical investigation utilizing Fourier-transform infrared spectroscopy (FTIR) revealed an increase in hydroxyl groups and carboxylic content following plasma treatment, which enhances electrochemical performance. Raman spectroscopy revealed a drop in the ID/IG ratio from 1.00 to 0.90, indicating enhanced graphitic order. Scanning electron microscopy (FESEM) showed that plasma treatment improves surface shape, while elemental analysis assessed the high carbon content (76.56% by weight). Contact angle measurements showed a decrease from 114° to 65°, showing improved hydrophilicity after treatment. Electrochemical investigation shows that the plasma-treated CSAC had a maximum specific capacitance of 1612 F g−1, compared to 729 F g−1 for the untreated CSAC, and a total capacitance of plasma treated1685 F/g are untreated 1400 F g−1. A Type II+III pattern on the isotherms implied capillary condensation in mesopores. The plasma treatment indicated improved porosity and potential adsorption capacity by increasing the specific surface area and decreasing the average pore width. The cyclic stability tests indicated that the plasma-treated CSAC retained 94% capacitance and 98% coulombic efficiency after 3000 cycles, which is superior to the untreated CSAC’s 92% capacitance retention and 95% coulombic efficiency. This reveals that plasma-treated CSAC has significantly improved performance and stability, making it an excellent alternative for high-performance and cost-effective energy storage applications.

Challenges and Modification Strategies on High-Voltage Layered Oxide Cathode for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have attracted great attention due to their advantages on resource abundance, cost and safety. Layered oxide cathodes (LOCs) of SIBs possess high theoretical capacity, facile synthesis and low cost, and are promising candidates for large scale energy storage application. Increasing operating voltage is an effective strategy to achieve higher specific capacity and also high energy density of SIBs. However, at high operating voltages, LOCs will undergo a series of phase transitions in bulk phase, leading to huge change of volume and layer spacings accompanied by severe lattice stress and cracking formation. Degeneration of surface also occurs between LOCs and electrolytes, resulting in sustained growth of cathode electrolyte interphase (CEI) and release of O2 and CO2. These induce structural destruction and electrochemical performance degradation in high voltage regions. Recently, many strategies have been proposed to improve electrochemical performance of LOCs under high voltages, including bulk element doping, structural design, surface coating and gradient doping. This review describes pivotal challenges and occurrence mechanisms at high voltages, and summarizes strategies to improve stability of bulk and surface. Viewpoints will be provided to promote development of high energy density SIBs.

Effects of Intercalation on ML-Ti3C2Tz MXene Properties and Friction Performance.

Intercalation in two-dimensional (2D) materials can modify their physical, chemical, and electronic properties. This modification enables the tailoring of 2D material characteristics, enhancing their performance and expanding their applications in various fields. The friction performance of 2D materials such as MoS2 and graphite has a strong dependence on their interlayer spacing, and they exhibit an increase in d-spacing associated with a reduction in friction performance. The ability to control the interlayer spacing of Ti3C2Tz MXene has proven beneficial for energy storage applications such as batteries and supercapacitors, but no one has utilized this control of interlayer spacing for lubrication. In this study, we demonstrate that interlayer spacing of multilayer (ML) Ti3C2Tz MXene can be controlled through chemical intercalation and its direct effects on the electrical conductivity and friction performance. We observed a notable decrease in electrical conductivity in vacuum-filtered ML-Ti3C2Tz MXene films, which was attributed to an increased internal resistance resulting from the expansion of the interlayer gap. We also found a significant reduction in the coefficient of friction for ML-Ti3C2Tz MXene with an increased d-spacing. This reduction is attributed to a weakened attraction of individual ML-Ti3C2Tz MXene layers (intercalated). Under a tangential force, it becomes easier to slide within the larger interlayer gap with weakened van der Waals forces. This work provides insights into the tunability of MXene properties through interlayer spacing, offering potential applications requiring materials with specific electrical and friction characteristics.

Metalloid Phosphorus Induces Tunable Defect Engineering in High Entropy Oxide Toward Advanced Lithium‐Ion Batteries

AbstractThe inferior electrical conductivity and sluggish lithium storage kinetics of conventional high‐entropy oxide (HEO) are critical issues hindering their commercialization. The high electronegativity of metalloids can ameliorate this predicament by altering the electronic configuration of HEO compared to metals. Herein, metalloid phosphorus doping in spinel‐type HEO (PxA1‐x)B2O4 (A/B = Cr, Mn, Fe, Co, Ni) (P‐HEO) is achieved through a facile sol–gel process. The metalloid phosphorus doping facilitates the transfer of electrons from transition metal sites to phosphorus‐doped sites, resulting in the formation of electron‐rich and electron‐deficient local regions on the HEO surface and is conducive to an increase in the total number of active lithium sites in the electrochemical reaction process. Density functional theory calculation reveals Li adsorption energy on the synthesized P‐HEO is only −1.102 eV, demonstrating that the phosphorus doping enables a strong electronic coupling between lithium ions and P‐HEO. Furthermore, metalloid phosphorus doping also leads to oxygen vacancies formation and lattice distortion, which significantly enhances charge transfer efficiency and diffusion kinetics and results in the enhanced lithium storage performance with impressive rate capability and long‐term stability. These findings provide valuable insights for the design of lattice‐engineered HEO as versatile electrodes for future energy storage applications.

High‐Performance Alkaline Battery‐Supercapacitor Hybrid Based on Bimetallic Phosphide/Phosphate

AbstractTransition metal‐based materials explored for energy storage applications viz. batteries, supercapacitors and more recently battery‐supercapacitor hybrids (BSHs) abundantly involve Co‐based materials. However, the supply chain issues and low electronic conductivity force us to look for alternative options. In this regard, Co‐free binary metal phosphide/phosphate consisting of Ni and V metal (NiVP/Pi) microspheres as the positive electrode of BSH which shows a high specific capacity of 502 C g−1 (1004 F g−1) at 2 mV s−1 while retaining a high specific capacity of 214 C g−1 (428 F g−1) at 12 A g−1 is reported. The high electronic conductivity of binary metal phosphide in NiVP/Pi electrode and the rich electrochemical active sites due to Ni and V metal centres results in exciting performance. More interestingly, the hybrid device is successfully developed by employing NiVP/Pi as the positive electrode and carbon nanotubes (CNTs) as the negative electrode. The hybrid device (NiVP/Pi//CNT) is able to achieve a maximum energy density of 22.17 Wh kg−1 and a power density of 5 kW kg−1 with 91.7% capacitance retention after 7500 continuous galvanostatic charge–discharge cycles.

Construction of Nano ZnV2O4/N‐Doped Porous Carbon Composites with Optimized Ionic and Electronic Conductivities as Competitive Cathodes toward Zinc‐Ion Capacitors

AbstractZinc‐ion capacitors (ZICs) have great potential for energy storage applications due to high safety, environmental friendliness, low cost, and high energy density. However, challenges such as poor ion diffusion kinetics and the low conductivity of cathode materials still need to be addressed. Nano ZnV2O4/nitrogen‐doped porous carbon (ZVO/N‐PC) composites are efficiently synthesized via a simple annealing process. Highly crystalline ZVO nanoparticles are in‐situ grown on the three‐dimensional N‐PC surface by precisely tuning the ratio of the vanadium source, achieving a dual enhancement in electronic and ionic conductivities. Benefiting from the nanoengineering build‐up, the optimized ZVO‐0.6/N‐PC anode exhibits impressive rate performance (405.9/308.8 mAh g−1 at 0.2/5.0 A g−1) and cycling capability (0.0029 % capacity drop per cycle at 5.0 A g−1 after 5,800 cycles). Using nitrogen‐doped porous activated carbon (N‐PAC) as the anode and ZVO‐0.6/N‐PC as the cathode, the assembled ZICs deliver a high energy density of 27.5 Wh kg−1 at a power density of 450.0 W kg−1. After 10,000 cycles at 1.0 A g−1, the capacity retention rate remains as 72.8 %, demonstrating excellent cycling stability. This highlights the promising application of nano ZVO/N‐PC composites towards ZICs as competitive cathodes.

Electroanalytical Probing of Triphasic Hydrogen Storage and Transport in Films of Nanoparticulate Polymer of Intrinsic Microporosity (PIM-1)

AbstractPreliminary experiments are reported to show quantitatively that hydrogen gas can be stored under triphasic conditions in wet nanoparticulate polymer of intrinsic microporosity (PIM-1) applied as a film to a platinum disk electrode surface. Based on chronoamperometric data, it is shown that the resulting triphasic interface is able to store hydrogen gas at apparent concentrations higher (3 orders of magnitude increase for an approx. 15 μm thick film with typically capp,hydrogen = 80 mM; Dapp,hydrogen = 1.2 × 10–11 m2s−1) than the known solubility of hydrogen gas in aqueous electrolyte (chydrogen = 0.08 mM; Dhydrogen = 5.0 × 10–9 m2s−1) at room temperature. Due to film roughness/heterogeneity, the apparent hydrogen concentration can only be estimated, but it increases with film thickness. At the same time the apparent diffusion coefficient is lowered considerably due to the molecularly rigid/glassy polymer host. The resulting modified electrode is investigated/proposed for energy storage applications with different amounts of PIM-1 nanoparticle deposits attached to the platinum surface. Graphical Abstract

Bacterial Cellulose Applications in Electrochemical Energy Storage Devices.

Bacterial cellulose (BC) is produced via the fermentation of various microorganisms. It has an interconnected 3D porous network structure, strong water-locking ability, high mechanical strength, chemical stability, anti-shrinkage properties, renewability, biodegradability, and a low cost. BC-based materials and their derivatives have been utilized to fabricate advanced functional materials for electrochemical energy storage devices and flexible electronics. This review summarizes recent progress in the development of BC-related functional materials for electrochemical energy storage devices. The origin, components, and microstructure of BC are discussed, followed by the advantages of using BC in energy storage applications. Then, BC-related material design strategies in terms of solid electrolytes, binders, and separators, as well as BC-derived carbon nanofibers for electroactive materials are discussed. Finally, a short conclusion and outlook regarding current challenges and future research opportunities related to BC-based advanced functional materials for next-generation energy storage devices suggestions are proposed.

Comparative Analysis of Structural, Optical, and Electronic Properties of Nickel Oxide and Potassium‐Doped Nickel Oxide Nanocrystals

ABSTRACTMetal oxide semiconductors, known for their exceptional optical transparency, high carrier mobility, and stability, have found extensive use in emerging technologies such as optoelectronics and energy storage devices. Among all metal oxide semiconductors, nickel oxide (NiO) stands out as a highly favorable candidate due to its p‐type conductivity along with its substantial band gap (3.5–4 eV) for the broad range of applications, including gas sensors, high‐rate Lithium‐ion batteries, high‐performance supercapacitors, and photovoltaic devices. In light of these versatile applications, our current study presents a comprehensive comparative analysis of the structural and optoelectronic properties of NiO and potassium (K)‐doped NiO nanocrystals. The nanocrystals were synthesized using the co‐precipitation route and subsequently annealed at 500°C under ambient conditions. The effect of K doping on the structural and optoelectronic characteristics was systematically examined using various techniques, including x‐ray diffraction, UV–visible spectroscopy, Raman spectroscopy, and Hall effect measurements. To explore the structural characteristics, XRD measurements were performed, which confirm the FCC structure of nanocrystals. The optical property analysis suggested that the formation of the energy level can contribute to reduction of the band gap. A sharp peak at 397 cm−1 is associated with NiO bond in FTIR spectra which verifies the formation of nanocrystals. Moreover, the incorporation of K increases the intensity of the Raman peaks, which provides evidence for the higher degree of crystallinity in doped samples. These results of Raman scattering are in good agreement with XRD outcomes. In addition, the resistivity of NiO nanocrystals decreases monotonically with the increasing K concentration. The results of temperature‐dependent resistivity further demonstrate that electrons required more energy to jump from one polaron state to another in the case of x = 0.01 M and 0.03 M doped Ni0.5‐xKxO samples. The combination of a diminished band gap and enhanced conductivity makes these materials exceptionally promising for applications in optoelectronics and energy storage.

The extraction of inorganic phase-change materials from sugar industry wastes with the purpose of solid waste management

ABSTRACT This study focused on the feasibility of identifying and recycling inorganic phase-change materials (PCMs) from sugar industry wastes in two cities of Qazvin and Hamadan in Iran. In this study, dry sugar beet pomace, sugar beet pomace, sugar beet molasses, leaves and plant residues of sugar beet and sugarcane bagasse were investigated. The inorganic materials were identified by X-ray Diffraction (XRD), thermal characteristics were determined by differential scanning calorimetry (DSC), and morphological characteristics were determined by scanning electron microscopy (SEM). Additionally, physical and thermal properties of molasses and bagasse samples were analyzed to determine their suitability as inorganic PCMs. The results of this study demonstrated that molasses and bagasse have the potential to be used as mineral PCMs in thermal energy storage applications. The results of this study demonstrated that in the wet sugar beet pomace the highest and lowest concentrations of inorganic PCMs were silicon dioxide (SiO2) and sodium chloride (NaCl), respectively. Moreover, the highest calcium fluoride (CaF₂) composition was reported in dry sugar beet pomace. In the samples of leaves and residues of sugar beet and sugarcane bagasse, the highest concentration of was NaCl. The detection and recycling of mineral PCMs from sugar industry wastes offer a sustainable solution for waste management and provide a renewable source of thermal energy storage materials. Implication Statement This study demonstrated the potential for the extraction of inorganic phase-change materials from sugar industry wastes as a means of solid waste management. By repurposing these materials, we can reduce the environmental impact of sugar production and contribute to sustainable practices in the industry.

Mechanical Unfolding of Network Nodes Drives the Stress Response of Protein-Based Materials.

Biomaterials synthesized from cross-linked folded proteins have untapped potential for biocompatible, resilient, and responsive implementations, but face challenges due to costly molecular refinement and limited understanding of their mechanical response. Under a stress vector, these materials combine the gel-like response of cross-linked networks with the mechanical unfolding and extension of proteins from well-defined 3D structures to unstructured polypeptides. Yet the nanoscale dynamics governing their viscoelastic response remains poorly understood. This lack of understanding is further exacerbated by the fact that the mechanical stability of protein domains depends not only on their structure, but also on the direction of the force vector. To this end, here we propose a coarse-grained network model based on the physical characteristics of polyproteins and combine it with the mechanical unfolding response of protein domains, obtained from single molecule measurements and steered molecular dynamics simulations, to explain the macroscopic response of protein-based materials to a stress vector. We find that domains are about 10-fold more stable when force is applied along their end-to-end coordinate than along the other tethering geometries that are possible inside the biomaterial. As such, the macroscopic response of protein-based materials is mainly driven by the unfolding of the node-domains and rearrangement of these nodes inside the material. The predictions from our models are then confirmed experimentally using force-clamp rheometry. This model is a critical step toward developing protein-based materials with predictable response and that can enable applications for shape memory and energy storage and dissipation.

Novel B6P6X (X=As, Sb) monolayers for antiferromagnetic spintronics and hydrogen storage

Embedding foreign atoms into porous two-dimensional (2D) materials has emerged as a promising strategy to tailor their electronic, magnetic, and adsorption properties, enabling promising applications in energy storage and spintronics devices. In this work, spin-polarized density functional theory (DFT) calculations were employed to investigate the ground state properties and hydrogen (H2) storage of interstitially X = As and Sb atom doped B6P6 (B6P6X) graphenylene monolayers. The resulting B6P6X (X = As, Sb) monolayers exhibit very good mechanical, dynamical, and thermal stabilities with antiferromagnetic (AFM) ground states. Electronic structure calculations reveal AFM semiconducting behavior for both monolayers, with indirect/direct band gaps of 0.71/0.60 eV (PBE) and 2.19/2.14 eV (HSE06) for B6P6As/B6P6Sb, respectively. All B6P6X monolayers exhibit an in-plane easy magnetization axis. The obtained Berezinskii-Kosterlitz–Thouless transition (BKT) temperature value of B6P6Sb monolayer is 268.74 K. Furthermore, the H2 storage capabilities of these B6P6X monolayers were examined. We find that B6P6As and B6P6Sb monolayers can each adsorb up to 48H2 molecules with an average adsorption energy (Ea) of -0.14 eV/H2. The corresponding H2 storage gravimetric capacities are 6.91 wt% for B6P6As@48H2 and 6.10 wt% for B6P6As@48H2, surpassing the U.S. Department of Energy’s 2025 target of 5.50 wt%. These findings highlighting the potential of B6P6X (X = As, Sb) monolayers for AFM spintronics and H2 storage applications.

Size and shape dependence of hydrogen-induced phase transformation and sorption hysteresis in palladium nanoparticles

Abstract Phase transitions of metals in hydrogen environments are critically important for applications in energy storage, catalysis, and sensing. Nanostructured metallic particles can lead to faster charging and discharging kinetics, increased lifespan, and enhanced catalytic activities. However, establishing a direct causal link between nanoparticle structure and function remains challenging. In this work, we establish a computational framework to explore the atomic configuration of a metal-hydrogen (M-H) system when in equilibrium with a H environment. This approach combines Diffusive Molecular Dynamics with an iteration strategy, aiming to minimize the system's free energy and ensure uniform chemical potential across the system that matches that of the H environment. Applying this framework, we investigate H chemical potential-composition isotherms during the hydrogenation and dehydrogenation of palladium nanoparticles, ranging in size from $3.9$ nm to $15.6$ nm and featuring various shapes including cube, rhombic dodecahedron, octahedron, and sphere. Our findings reveal an abrupt phase transformation in all examined particles during both H loading and unloading processes, accompanied by a distinct hysteresis gap between absorption and desorption chemical potentials. Notably, as particle size increases, absorption chemical potential rises while desorption chemical potential declines, consequently widening the hysteresis gap across all shapes. Regarding shape effects, we observe that, at a given size, cubic particles exhibit the lowest absorption chemical potentials during H loading, whereas octahedral particles demonstrate the highest. Moreover, octahedral particles also exhibit the highest desorption chemical potentials during H unloading. These size and shape effects are elucidated by statistics of atomic volumetric strains resulting from specific facet orientations and inhomogeneous H distributions. Prior to phase transformation in absorption, a H-rich surface shell induces lattice expansion in the H-poor core, while before phase transformation in desorption, surface stress promotes lattice compression in the H-rich core. The magnitude of the volumetric strains correlates well with the size and shape dependence, underlining their pivotal role in the observed phenomena.

Enhanced photocatalytic hydrogen and oxygen evolution activity by two-dimensional van der Waals AlSb/ZnO heterostructure: A first-principles study

Photocatalytic water splitting facilitates the generation of green hydrogen energy by transforming renewable solar energy into chemical energy. This paper investigated the electronic, optical, and photocatalytic properties of AlSb/ZnO van der Waals (vDW) heterostructure using density functional theory. AlSb/ZnO, a semiconductor heterostructure with an indirect bandgap, was energetically stable with a formation energy of −0.4 eV as well as dynamically and thermally stable. The band edges of the 2D heterostructure maintained the essential redox energy levels for complete water splitting, allowing hydrogen and oxygen generation. Moreover, the heterostructure exhibited a high absorption coefficient in the visible region of the solar spectrum compared to the individual AlSb and ZnO monolayers. We revealed low barrier potential at neutral pH conditions for oxygen and hydrogen evolution reactions from the Gibbs free energy calculation without any external potential. Our study additionally showed the solar-to-hydrogen efficiency of 27.93% and a carrier utilization efficiency of 42.83%, indicating the AlSb/ZnO heterostructure as an excellent water splitting photocatalyst with remarkable potential for fuel cells and energy storage applications.

Electrochemical oxidation-driven formation of nickel/nickel-based compounds on hollow carbon shells: Mechanistic insights and energy storage applications

Hydrangea-like nickel/nickel-based compounds decorated hollow carbon shells were synthesized through low-temperature calcination and a facile electrochemical oxidation process. This three-dimensional hollow hierarchical structure ensures intimate contact between the electrically conductive nickel (Ni) substrate and uniformly distributed electrochemically active nickel-based compounds. This hierarchical structure offers abundant active sites and accessible pathways, maximizing energy storage, particularly during rapid charge–discharge cycles. With 30 min of electrochemical oxidation, the optimized Ni-compound-based electrode exhibits a specific capacity of 643 C g−1 at 1 A/g. When assembled into a nickel-zinc battery cell with a zinc foil anode, the cell demonstrates swift current responses, with full capacity recovery even after a twentyfold increase in current density, followed by a return to 1 A/g. Density functional theory computations reveal that the electrochemical oxidation, conducted for an optimized duration, results in partial oxidation of Ni(OH)2, reducing the surface adsorption energy of OH− from the electrolyte and improving charge storage capacity.

Promoting Nickel-Iron layered double hydroxide via In-situ sulfur doping for efficient bifunctional electrocatalysis and energy storage applications

Promoting Nickel-Iron layered double hydroxide via In-situ sulfur doping for efficient bifunctional electrocatalysis and energy storage applications

Ginkgo biloba-derived biogenic carbon quantum dots modified NiCo-LDH: significantly enhanced energy density and cycle stability

A significant development in the usage of hydroxides in energy storage applications is the creation of LDH materials with excellent electrical conductivity and structural stability. Due to their poor electrical conductivity, bimetallic layered double hydroxides have weak rate performance and limited cycling ability. To address these issues, carbon quantum dots derived from waste Ginkgo biloba and labeled as GBC were incorporated in the preparation of NiCo-LDH. With the many oxygen-containing functional groups on the surface, GBC increases the composite's wettability while maintaining the LDH lamellar structure. It can also create localized electron-rich regions, which give the material more space and channels for electron transport, improving electrical conductivity and rate performance. Furthermore, GBC is evenly dispersed throughout the LDH skeleton, giving the composites a homogenous surface state that can mitigate the structural collapse issue brought on by the volume change during cycling. The findings demonstrate that by modulating the amount of GBC, NiCo-LDH/GBC-20 performs better electrochemically than NiCo-LDH. The capacity was 276.1 mAh g-1 at 1 A g-1, an 84.1% improvement over NiCo-LDH. Finally, the energy density displayed by the NiCo-LDH/GBC-20//AC HSC device is 72.5 Wh kg-1 (at 798.7 W kg-1), and maintains 78.2% of its original capacity after 12,000 cycles.