Electrode Materials For Energy Storage Devices Research Articles

Efficient green combustion production of pure nickel oxide (NiO) and silver-doped NiO nanoparticles using Aloe Vera gel extract: Its supercapacitors applications

This study employs the synthesis of pure NiO and Ag-doped NiO with varying concentrations (1, 3, 5, 7 and 9 mol%) of Ag2O nanoparticles by solution combustion method. The Structural and morphology of nanomaterials were elucidated by analytical spectroscopic methods. XRD revealed alterations in physical properties, such as crystallite size and lattice parameters, of NiO nanoparticles due to the presence of Ag2O. UV-Vis spectroscopy demonstrated a reduction in the bandgap from 3.41 eV (pure NiO) to 3.21 eV for 1, 3, 5, 7 and 9 mol% Ag2O-doped NiONPs. To assess their viability as active electrode materials in supercapacitors, the synthesized samples were subjected to analysis in a 0.1 M HCl electrolyte. Electrochemical studies done through various tests, including Electrochemical-Impedance, Cyclic-Voltammetry and Galvanic Charge-Discharge. Remarkably, the 5 mol% Ag2O-doped NiO in a 3-electrode system exhibited a notable capacitance value of 248 Fg−1 at a scan rate of 5 Ag−1. Additionally, it demonstrated robust cycling stability, maintaining over 90% of the original capacitance after 2000 cycles in GCD studies. The potential chemical interaction between nanoscale Ag2O and NiO could be responsible for the enhanced capacitance. These findings offer valuable insights for researchers exploring the development of novel electrode materials for energy-storage devices.

Hierarchical nanocomposites of redox covalent organic frameworks nanowires anchored on graphene sheets for super stability supercapacitor

Covalent organic frameworks (COFs) have shown significant potential as ideal electrode materials for supercapacitors (SCs) due to their highly accessible surface areas and tunable active sites. However, their poor electrochemical properties hinder their application prospects in electrochemical energy storage devices. Herein, we successfully synthesized two-dimensional COF (TpPa-(OH)2) nanowires anchored on the surface of reduced graphene oxide (TpPa-(OH)2/rGO) using a facile hydrothermal method in aqueous solution. The anchored COFs nanowires effectively prevent graphene sheets from stacking, thereby enhancing the electronic double layer capacitor of rGO and introducing pseudo-capacitance contributed by the redox COFs. Additionally, rGO's inherent conductivity facilitates electron transfer and ion migration, improving electrochemical properties. By regulating the content ratio of graphene and COF, the optimal TpPa-(OH)2/rGO shows obvious COFs nanowires structure anchored on graphene sheets and exhibits exceptional electrochemical performance, with a high specific capacitance of 371.1 F/g at 0.5 A/g and excellent cycle stability of 93% after 20,000 cycles at 10 A/g. Furthermore, we assembled symmetric SCs (SSCs) using TpPa-(OH)2/rGO-3, achieving a specific capacitance of 197.1 F/g at 0.2 A/g and delivering a maximum energy density of 16.6 Wh/kg at a power density of 158.7 W/kg. These results unambiguously indicate the significant potential of TpPa-(OH)2/rGO as a high-performance electrode material in energy-storage devices.

Nanosheet@nanosheet NiZn2O4@NiZn2S4 core-shell mesoporous heterostructure as an electrode material for aqueous hybrid supercapacitors

Reasonable design of nanocomposite electrode materials with core-shell heterostructures is crucial to improve their electrochemical performance and enhance structural stability. Herein, a novel nanosheet@nanosheet NiZn2O4@NiZn2S4 (NZO@NZS) core-shell mesoporous heterostructure was synthesized on nickel foam (NF) as an electrode material for aqueous hybrid supercapacitors (HSCs). The interconnected NZS nanosheets were uniformly anchored to the vertically aligned NZO nanosheets, improving the conductivity and stability of the composite, consequently rendering the composite to exhibit excellent electrochemical performance. At a current density (Dc) of 1 A g−1, the NZO@NZS exhibits a high specific capacity (Cs) of 1516.0 C g−1. After 10,000 cycles (Dc = 15 A g−1), its capacity retention rate maintains at 86.9 %. Moreover, an HSC was assembled using the NZO@NZS as positive electrode and activated carbon as the negative electrode). At a power density (PD) of 775.0 W kg−1, the energy density (ED) is 43.4 Wh kg−1. Thus, the NZO@NZS exhibits potential as an electrode material in energy-storage devices.

Hierarchical carbon layer coated NiCoP nanoparticles embedded on nitrogen-doped carbon nanotubes for high-performance supercapacitors

Transition metal phosphides (TMPs) have been widely recognized as an ideal choice for supercapacitors (SCs) due to exceptional pseudocapacitance performance. Otherwise, reasonable structural design of TMPs can overcome the defects of low rate performance and poor cycle life. Furthermore, the incorporation of carbon materials can enhance electronic conductivity, thereby enabling rapid electron transmission. Herein, we present a novel hierarchical carbon layer coated NiCoP nanoparticles embedded on nitrogen-doped carbon nanotubes (NiCoP/NCNTs), synthesized through a calcination/phosphorization process. By incorporating a carbon layer to anchor nanoscale NiCoP, an increased number of active sites and improved structural stability are achieved. Furthermore, the presence of NCNTs enhances the electronic conductivity. These combined features result in impressive performance, with NiCoP/NCNTs exhibiting an impressive specific capacitance of 1628.4 F/g at 1 A/g, and good rate capability of 78.5 % up to 50 A/g. Moreover, it also exhibits outstanding cycling stability, maintaining a capacitance retention of 71.4% after 10 000 cycles. Moreover, the asymmetric SCs based on NiCoP/NCNTs and AC deliver a high energy density of 45.46 Wh/kg, and exhibit excellent cycling stability of 92.5% after 5000 cycles. These results highlight the potential of NiCoP/NCNTs as a novel battery-type electrode material for energy-storage devices.

Advances in the Development of Single-Atom Catalysts for High-Energy-Density Lithium-Sulfur Batteries.

Although lithium-sulfur (Li-S) batteries are promising next-generation energy-storage systems, their practical applications are limited by the growth of Li dendrites and lithium polysulfide shuttling. These problems can be mitigated through the use of single-atom catalysts (SACs), which exhibit the advantages of maximal atom utilization efficiency (≈100%) and unique catalytic properties, thus effectively enhancing the performance of electrode materials in energy-storage devices. This review systematically summarizes the recent progress in SACs intended for use in Li-metal anodes, S cathodes, and separators, briefly introducing the operating principles of Li-S batteries, the action mechanisms of the corresponding SACs, and the fundamentals of SACs activity, and then comprehensively describes the main strategies for SACs synthesis. Subsequently, the applications of SACs and the principles of SACs operation in reinforced Li-S batteries as well as other metal-S batteries are individually illustrated, and the major challenges of SACs usage in Li-S batteries as well as future development directions are presented.

Beauty in Imperfection

Redox-site engineering at the molecular level holds great promise in the exploration of advanced electrode materials for energy-storage devices. In this issue of Joule, Yijin Liu and colleagues derived a novel nickel-cobalt (NiCo) layered double hydroxide (LDH) electrode of high energy and powder density via electrochemically driven phase-transformation of a NiCo carbonate hydroxide. The dynamic synthesis process resulted in a LDH electrode that is oxygen vacancy enriched and contains abundant, unique 5-coordinated Co redox active sites with extraordinary fast reaction kinetics.

Encapsulation of hollow Cu2O nanocubes with Co3O4 on porous carbon for energy-storage devices

Co3O4 is one of the most studied transition-metal oxides for use in energy-storage devices. However, its poor conductivity and stability limit its application. In this study, a facile method for anchoring Co3O4-encapsulated Cu2O nanocubes on porous carbon (PC) to form Cu2O@Co3O4/PC was developed. The Cu2O@Co3O4/PC composite exhibited superior electrochemical performance as a supercapacitor electrode material. The resultant supercapacitor delivered high specific capacitance (1096 F g−1 at 1 A g−1), high rate capability (83 % retention at 10 A g−1), and excellent cycling stability (95 % retention of initial capacitance after 3000 cycles). Moreover, an asymmetric supercapacitor fabricated by coupling a Cu2O@Co3O4/PC positive electrode with a reduced graphene oxide negative electrode exhibited high energy density (32.1 W h kg−1 at 700 W kg−1). Thus, our results demonstrate that Cu2O@Co3O4/PC is a promising electrode material for energy-storage devices.

3D hierarchically gold-nanoparticle-decorated porous carbon for high-performance supercapacitors

Porous carbon are excellent electrode materials for energy-storage devices. Here, we present a facile in-situ reduction method to improve the electrochemical performance of carbon materials by gold nanoparticles. The prepared porous carbon microspheres decorated with gold-nanoparticle had a 3D honeycomb-like structure with a high specific surface area of about 1635 m2 g−1, confirmed by scanning electron microscopy, transmission electron microscopy, and the Brunauer-Emmett-Teller method. The electrochemical performance of as-synthesized porous carbon microspheres was exemplified as electrode materials for supercapacitor with a high specific capacitance of 440 F g−1 at a current density of 0.5 A g−1, and excellent cycling stability with a capacitance retention of 100% after 2000 cycles at 10 A g−1 in 6 M KOH electrolyte. Our method opened a new direction for the gold-nanoparticle-decorated synthesis of porous carbon microspheres and could be further applied to synthesize porous carbon microspheres with various nanoparticle decorations for numerous applications as energy storage devices, enhanced absorption materials, and catalytical sites.

Graphdiyne-Based Materials: Preparation and Application for Electrochemical Energy Storage.

Graphdiyne (GDY) has drawn much attention for its 2D chemical structure, extraordinary intrinsic properties, and wide application potential in a variety of research fields. In particular, some structural features and basic physical properties including expanded in-plane pores, regular nanostructuring, and good transporting properties make GDY a promising candidate for an electrode material in energy-storage devices, including batteries and supercapacitors. The chemical structure, synthetic strategy, basic chemical-physical properties of GDY, and related theoretical analysis on its energy-storage mechanism are summarized here. Moreover, through a view of the mutual promotion between the structure modification of GDY and the corresponding electrochemical performance improvement, research progress on the application of GDY for electrochemical energy storage is systematically explored and discussed. Furthermore, the development trends of GDY in energy-storage devices are also comprehensively assessed. GDY-based materials represent a bright future in the field of electrochemical energy storage.

On the synthesis of a compound with positive enthalpy of formation: Zinc-blende-like RuN thin films obtained by rf-magnetron sputtering

4d- and 5d-transition metal nitrides are of interest both because of their importance for the understanding of mechanisms of phase formation in systems that under ambient conditions present positive enthalpies of formation and because of their appealing structural and electronic properties. In this study, we report the synthesis of thin films of ruthenium mononitride (RuN) in the zinc-blende structure by radio-frequency-magnetron sputtering. Films present a characteristic structure of packed columns ending with tetrahedral tips. The effect of changing the synthesis parameters was investigated in detail. It was found that RuN can be formed if the nitrogen partial pressure exceeds a minimum value and that the addition of argon has the major effect of increasing the deposition rate because of its higher sputter ability. Temperature plays an important role: if it is too high, decomposition/desorption effects overcome those leading to the formation of the compound. Phenomena resulting in the formation of RuN occur at the surface of the growing films and are related to the interactions of ruthenium with energetic nitrogen ions, or atoms, which can penetrate the first atomic layers by low energy implantation. Because of its properties and structure, this material is a promising candidate for applications like sensing, catalysis, and electrode material for energy-storage devices.

Application of sputtered ruthenium nitride thin films as electrode material for energy-storage devices

RuN films that crystallized in the ZnS-like structure with [1 1 1] preferred orientation have been deposited by reactive sputtering. Preliminary results are reported on the electrochemical properties of such films as electrode materials for supercapacitors and lithium-ion batteries. Cyclic voltammetric experiments indicate an attractive capacitance value of 37 F g−1. Moreover, galvanostatic measurements indicate that RuN films reversibly react with lithium through a conversion reaction with Ru(0) nanoparticle formation. A high capacity value of ∼700 mAh g−1 at C/2 rate is achievable.