Electrode Material For Storage Research Articles

Facile synthesis of Veitchia merilli coir-based porous carbon using combined chemical and physical activation routes as electrode material for energy storage

This study aimed to prepare Veitchia merilli coir (VMC) through pre-carbonisation process, followed by chemical activation using potassium hydroxide as an activating agent. The experiment was conducted under different pyrolytic physical activation temperatures of 650, 700, and 750 °C with the code VMS-650, VMS-700, and VMS-750 for each sample. Physical activation methods develop or modify the pore structure, specific surface area, and microstructure of activated carbon. Furthermore, the prepared VMCs were characterised using X-ray diffraction, Fourier transform infrared, scanning electron microscope, energy dispersive X-ray, and cyclic voltammetry with a symmetrical two-electrode system in 1 M H2SO4 solution. The microstructure analysis showed that the VMC carbon electrode has an amorphous structure with two broad peaks at 2θ angles around 26° and 44° corresponding to the (002) and (100) planes, with the L c VMS-700 having a value of 16.007 nm. The VMC electrode has a C≡C carbon bond as a functional group, which extends in bands from 2311.79 to 2373.51 cm−1. Meanwhile, the VMS-700 electrode shows a combined surface morphology of nanofibers as well as mesopores, and the energy dispersive X-ray results showed carbon content of 92.83%. The electrochemical properties of supercapacitor cells indicated this electrode had the highest specific capacitance value of 264.2 F g−1. From the obtained results, the respective physical and electrochemical properties of the carbon electrodes and supercapacitor cells showed that the activated VMC-700 at 700 °C is the optimum temperature to produce the best performance compared to 650 and 750 °C.

3DG/Se4.7S3.3 composites with different morphologies as new all-solid-state lithium storage electrode materials

Selenium-sulfur(SexSy) composites can be used as energy storage materials for lithium batteries benefit from their integration of the high capacity of sulfur and the high conductivity of selenium. Herein, we prepared amorphous three dimensional reduced graphene oxide/selenium sulfide(a-3DG/Se4.7S3.3) composites and crystalline 3DG/Se4.7S3.3(c-3DG/Se4.7S3.3) composites by in situ synthesis and hydrothermal methods, respectively, in order to research the effect of different morphologies of 3DG/Se4.7S3.3 composites on the electrochemical properties of all-solid-state lithium batteries. Our study found that the a-3DG/Se4.7S3.3 cathodes displayed greater capacity and outstanding rate performance, with an initial discharge capacity of 926 mAh g−1 and utilization rate of 103% at 1/2C. And a first discharge capacity of up to 706 mAh g−1 at 7 C. Although the first discharge capacity of c-3DG/Se4.7S3.3 was 523 mAh g−1, its cycling stability was significantly improved compared with that of a-3DG/Se4.7S3.3 cathodes, and the Coulombic efficiency remained above 97% after 60 cycles at ½ C. In this work, we investigate the performance of solid-state batteries by preparing new SexSy composites with different morphologies and rational design of electrodes in terms of structure and morphology, which provides ideas for the preparation of electrodes in the future.

Flexible self-supporting CoFe-LDH/MXene film as a chloride ions storage electrode in capacitive deionization

Excessive chloride ions (Cl-) are undesirable in water. However, most of the research on the application of capacitive deionization in desalination has focused on cation storage electrode materials, whereas less on the equally important Cl- storage electrode materials. Herein, the CoFe-Layered Double Hydroxide (CoFe-LDH) prepared by chemical co-precipitation was composited with MXene through simple vacuum filtration to form a self-supporting CoFe-LDH/Ti3C2Tx film electrode, and used as the anode material to store Cl- in the hybrid capacitive deionization system. The CoFe-LDH/Ti3C2Tx composite film has a hierarchical micro-mesoporous architecture, larger electrochemical capacity, and desalination capacity, reaching 149.25 ± 6.17 mg g−1 at a current density of 50 mA g−1 and desalination rate of 3.86 mg g−1 min−1 at 100 mA g−1. This work provides potential inspiration for the Cl- storage electrode for capacitive deionization technology.

Hollow FeS2 nanospheres encapsulated in N/S co-doped carbon nanofibers as electrode material for electrochemical energy storage

Pyrite iron sulfide (FeS2) is a fascinating electrode material for energy reserve devices because of its high theoretical capacity, non-polluting nature and abundant resources. However, the practical application has been extremely inhibited owing to its poor rate capacity and short cyclability caused by volume change during charge/discharge processes. In this article, a novel nanocomposite that is hollow FeS2 nanospheres encapsulated in N/S co-doped carbon nanofibers (FeS2CNFs) was synthesized through electrostatic spinning. The FeS2CNFs nanocomposite demonstrates a terrific specific capacity of 511 F g−1 at 1 A g−1 for all-solid-state supercapacitors. The FeS2CNFs as electrode material for sodium-ion batteries (SIB) displays a specific capacity of 827.7 mAh g−1 and possesses a capacity of 490.6 mAh g−1 at 0.05 A g−1 after 200 cycles. The results indicate that this encapsulated structure can guarantee the integrity of electrode materials. And the abundant defects in carbon nanofibers caused by N/S co-doping may increase electrochemical reaction sites to facilitate charge transfer. The N/S co-doped FeS2CNFs nanocomposite exhibits a great potential for applying in SIB and supercapacitors.

Ultrafast flashlight sintered mesoporous NiO nanosheets for stable asymmetric supercapacitors

Ultrafast flashlight sintering (FLS) has become an important green manufacturing technology for the structural reformation of various nanomaterials. Nickel oxide (NiO) has been extensively studied as a promising electrode material for electrochemical energy storage owing to its high theoretical specific capacitance, low cost, and appropriate chemical compatibility. This study reports the fabrication of mesoporous ultrathin NiO nanosheets on carbon cloth (CC) as green electrodes for flexible supercapacitors (SCs) through an exceptional ultrafast millisecond FLS process at room temperature. The optimized FLS-NiO@i12J electrode exhibited a remarkable specific capacity of 202.3 mA h g−1 (1215 F g−1) at a current density of 2 A g−1. Strikingly, the as-fabricated FLS-NiO electrodes outperformed the time and energy-consuming conventional thermally annealed (CTA) NiO electrodes. Furthermore, the flexible FLS-NiO@i12J//rGO asymmetric SCs deliver a remarkable energy density of 47.18 Wh kg−1 at a power density of 758.37 W Kg−1 and extraordinary cycling stability performance after 15,000 cycles. In addition, the FLS-NiO@i12J electrodes offer unique mesoporous structures, high surface areas, and numerous open-pore channels of ultrathin NiO nanosheets that facilitate fast transport of ions and rapid redox reactions. Thus, the present approach is promising for designing advanced electrode materials for flexible energy storage applications.

Nitrogen-doped carbon nanofibers derived from phenolic-resin-based analogues for high-performance lithium-ion batteries

The preparation of one-dimensional (1-D) carbon nanofibers (CNFs) for lithium-ion battery (LIB) anode materials plays a crucial role in electrochemical energy storage, but it still remains a great challenge due to the limited synthesis methods. Herein, we use a facile strategy to prepare the nitrogen-doped porous CNFs with high aspect ratio by direct pyrolysis of their phenolic-resin-based precursors in ammonium atmosphere. The polymer precursors are synthesized via a hydrothermal approach and have very high carbon yield over 50% in mass. Benefited from the unique 1-D porous structure, high nitrogen content and good conductivity, the ammonium-treated N-doped porous CNFs demonstrate an outstanding electrochemical lithium storage performance. The as-prepared N-doped porous CNFs demonstrates a high irreversible capacity of 325.2 mA h g−1 at 1000 mA g−1 together with an excellent long cycling performance (485.1 mA h g−1 at 500 mA g−1) after 500 cycles. This work offers a facile preparation strategy of the N-doped porous CNFs for high-efficiency energy storage electrode materials.

Prolific intercalation of VO2 (D)/polypyrrole/g-C3N4 as an energy storing electrode with remarkable capacitance

VO2 (D)/polypyrrole/g-C3N4 composites are synthesized through in situ chemical oxidation polymerization, and used as an electrode material for excellent energy storage.

Freestanding carbon nanofibers encapsulating MOF-derived NiSe with in-situ porous carbon protective layer for sodium storage

NiSe is considered to be an effective sodium storage electrode material due to its eminent theoretical capacity and ultra-long-term cycle life. Nonetheless, the large volume fluctuation and slow reaction kinetics cause NiSe to exhibit poor rate performance and cycle stability. Furthermore, the conventional electrode preparation technique necessitates the use of conductive and binder chemicals, resulting in poor electrochemical performance. To address these issues, freestanding NiSe-based electrodes (NiSe@C@NCNFs) are successfully fabricated via electrospinning Ni-MOF precursors and subsequent selenization reactions that NiSe nanoparticles are in-situ protected by MOF-derived porous carbon, thus ensuring the long-term cycling stability for sodium storage. Furthermore, the unique electrode structure design can improve the anode-electrolyte interface contact, shortening the sodium ionic transport path and quickening reaction kinetics. According to corresponding kinetics analysis, the sodiation/desodiation process of NiSe@C@NCNFs is a dominant surface pseudo-capacitance process, guaranteeing their prominent rate capability.

Highly ordered nanoscale phosphomolybdate-grafted polyaniline/metal hybrid layered structures prepared via secondary sputtering phenomenon as high-performance pseudocapacitor electrodes

The development of energy storage electrode materials is important for enhancing the electrochemical performance of supercapacitors. Despite extensive research on improving electrochemical performance with polymer-based materials, electrode materials with micro/nanostructures are needed for fast and efficient ion and electron transfer. In this work, highly ordered phosphomolybdate (PMoO)-grafted polyaniline (PMoO-PAI) deposited onto Au hole-cylinder nanopillar arrays is developed for high-performance pseudocapacitors. The three-dimensional nanostructured arrays are easily fabricated by secondary sputtering lithography, which has recently gained attention and features a high resolution of 10 nm, a high aspect ratio greater than 20, excellent uniformity/accuracy/precision, and compatibility with large area substrates. These 10 nm scale Au nanostructures with a high aspect ratio of ∼30 on Au substrates facilitate efficient ion and electron transfer. The resultant PMoO-PAI electrode exhibits outstanding electrochemical performance, including a high specific capacitance of 114 mF cm−2, a high-rate capability of 88%, and excellent long-term stability.

Decoupling Proton and Cation Contributions to Capacitive Charge Storage in Birnessite in Aqueous Electrolytes

AbstractNanostructured birnessite is of interest as an electrode material for aqueous high power electrochemical energy storage as well as desalination devices. In neutral pH aqueous electrolytes, birnessite exhibits a capacitive response attributed to the adsorption of cations and protons at the outer surface and within the hydrated interlayer. Here, we utilize the understanding of proton‐coupled electron transfer (PCET) in buffered electrolytes to decouple the role of protons and cations in the capacitive charge storage mechanism of birnessite at neutral pH. We find that without buffer, birnessite exhibits primarily potential‐independent (capacitive) behavior with excellent cycling stability. Upon the addition of buffer, the capacity initially increases and the cyclic voltammograms become more potential‐dependent, features attributed to the presence of PCET with the birnessite. However, long‐term cycling in the buffered electrolyte leads to significant capacity fade and dissolution, which is corroborated through ex situ characterization. ReaxFF atomistic scale simulations support the observations that proton adsorption leads to birnessite degradation and that capacitive charge storage in birnessite is primarily attributed to cation adsorption at the outer surface and within the interlayer.

A Simple and Expeditious Route to Phosphate-Functionalized, Water-Processable Graphene for Capacitive Energy Storage.

Phosphate-functionalized carbon-based nanomaterials have attracted significant attention in recent years owing to their outstanding behavior in electrochemical energy-storage devices. In this work, we report a simple approach to obtain phosphate-functionalized graphene (PFG) via anodic exfoliation of graphite at room temperature with a high yield. The graphene nanosheets were obtained via anodic exfoliation of graphite foil using aqueous solutions of H3PO4 or Na3PO4 in the dual role of phosphate sources and electrolytes, and the underlying exfoliation/functionalization mechanisms are proposed. The effect of electrolyte concentration was studied, as low concentrations do not lead to a favorable graphite exfoliation and high concentrations produce fast graphite expansion but poor layer-by-layer delamination. The optimal concentrations are 0.25 M H3PO4 and 0.05 M Na3PO4, which also exhibited the highest phosphorus contents of 2.2 and 1.4 at. %, respectively. Furthermore, when PFG-acid at 0.25 M and PFG-salt at 0.05 M were tested as an electrode material for capacitive energy storage in a three-electrode cell, they achieved a competitive performance of ∼375 F/g (540 F/cm3) and 356 F/g (500 F/cm3), respectively. Finally, devices made up of symmetric electrode cells obtained using PFG-acid at 0.25 M possess energy and power densities up to 17.6 Wh·kg–1 (25.3 Wh·L–1) and 10,200 W/kg; meanwhile, PFG-salt at 0.05 M achieved values of 14.9 Wh·kg–1 (21.3 Wh·L–1) and 9400 W/kg, with 98 and 99% of capacitance retention after 10,000 cycles, respectively. The methodology proposed here also promotes a circular-synthesis process to successfully achieve a more sustainable and greener energy-storage device.

Manganese oxide as an effective electrode material for energy storage: a review

Manganese oxide as an effective electrode material for energy storage: a review

Electrochemical supercapacitor application of CoFe2O4 nanoparticles decorated over graphitic carbon nitride

Fast-growing energy demands for the next generation quest for the development of engineered nanostructured electrode materials. In this direction, we report the performance and design of well crystalline cobalt ferrite nanoparticles (NPs) decorated on graphitic carbon nitride (CoFe2O4/GCN composite) for supercapacitor. The glycol functionalised composite material that was synthesized by a solvothermal process exhibits high specific capacitance (Csp) with long cyclic stability. The superior electrochemical properties are attributed to the presence of multiple oxidation states of cobalt ions, high surface area, nitrogen-rich structure, and porous nature that enables fast ion diffusion. Moreover, polyol functionalization increases hydrophilicity and improves the wettability of the composite which enhances the utilization rate of specific surface area. The composite based electrode exhibited a high Csp of 524 F/g @ 2 mV/s with superior capacitance retention (~ 98%) even after 5000 cycles at 8 A/g in 2 M KOH aqueous electrolytes. The power law and Trasatti method provide a qualitative analysis of the diffusivity of the NPs at the electrode/electrolyte interface. Presence of an ample number of electrochemically active sites and defect sites in the nanosheet structures of GCN modulate the electrochemical properties. The results evident that GCN composite can be one of the economical and active candidates as energy storage electrode materials.

Surface Chemistry and Mesopore Dual Regulation by Sulfur-Promised High Volumetric Capacity of Ti3 C2 Tx Films for Sodium-Ion Storage.

Electrochemical sodium-ion storage has come out as a promising technology for energy storage, where the development of electrode material that affords high volumetric capacity and long-term cycling stability remains highly desired yet a challenge. Herein, Ti3 C2 Tx (MXene)-based films are prepared by using sulfur (S) as the mediator to modulate the surface chemistry and microstructure, generating S-doped mesoporous Ti3 C2 Tx films with high flexibility. The mesoporous architecture offers desirable surface accessibility without significantly sacrificing the high density of Ti3 C2 Tx film. Meanwhile, the surface sulfur doping of Ti3 C2 Tx favors the diffusion of sodium ions. These merits are of critical importance to realize high volumetric capacity of the electrode material. As a consequence, as the freestanding electrode material for electrochemical sodium-ion storage, the S-doped mesoporous Ti3 C2 Tx film exhibits a high volumetric capacity of 625.6 mAh cm-3 at 0.1 A g-1 , which outperforms that of many reported electrodes. Moreover, outstanding rate capability and excellent long-term cycling stability extending 5000 cycles are achieved. The work opens the door for innovative design and rational fabrication of MXene-based films with ultrahigh volumetric capacity for sodium-ion storage.

Superior capacitive storage behavior of porous carbon electrode with high mass loading

Porous carbon (PC) derived from the petroleum pitch via the template-guidance coupled with activation methodology, possesses hierarchical pore structure in view of micropore and mesopore. As the electrode material for electrochemical double-layer capacitor, PC electrode not only possesses the good adaptability to aqueous and organic electrolytes, but also delivers the superior capacitive behavior with respect to capacitance and rate capability over those of counterparts (activation-derived carbon and commercial activated carbon). Furthermore, relatively high values of gravimetric and areal capacitances (247F g−1 and 2470 mF cm−2) can be guaranteed simultaneously for PC electrode even at the commercial-level mass loading of 10 mg cm−2, demonstrating the good compatibility to gravimetric and areal capacitances. The satisfactory capacitive storage behavior of PC is ascribed to the synergistic effect of hierarchical pore structure and extraordinary structural integrity. Besides, this work also presents a high value-added utilization strategy to prepare the high-performance porous carbon-based electrode material for capacitive energy storage.

Sonochemically synthesized nanostructured ternary electrode material for coin-cell-type supercapacitor applications

Two-dimensional MoS2-based composite has remarkable potential as an electrode material for advanced energy storage. However, the potential application of MoS2 electrode is limited by its low electrical conductivity and cyclic stability. Herein, a novel three/two-dimensional (3D/2D) ternary nanostructured composite consisting of MoS2/g-C3N4/reduced graphene oxide (rGO), denoted as MCNG, is synthesized using an in-situ sonochemical-assisted method. Owing to the combined 3D/2D morphological features, large surface area, enriched interfacial conductivity, numerous surface-active edge sites, and mesoporous structure, the composite electrode exhibits a remarkable specific capacitance of 663 F g−1 at current density of 0.5 A g−1 and outstanding cyclic stability with a retention of 91.7% after 10,000 charge–discharge cycles. A coin-cell-type asymmetric supercapacitor composed of MCNG as the positive electrode and activated carbon (AC) as the negative electrode, presents an energy density of 11.43 Wh kg−1 at a power density of 4125 W kg−1. This synthesis scheme provides a new pathway for the development of multi-component 3D/2D sheet-like networks as efficient electrode materials and their applications in energy storage devices.

Solvothermal synthesis of FeMnO3 nanobelts with excellent electrochemical performances for lithium-ions batteries and supercapacitors

One-dimensional nanobelt with inner nanopores has been considered as an ideal electrode material for electric energy storage. Herein iron manganese trioxide (FeMnO3) nanobelts have been prepared by a facile solvothermal approach. The phase, composition, structure and morphology of the as-synthesized sample are characterized by several techniques. Benefiting from the unique structure, the as-prepared FeMnO3 nanobelts achieve a superior lithium storage capacity with 635.7 mAh g−1 after 200 cycles, excellent cyclability and good kinetic properties, as well as a high specific capacitance of 209 F g−1 after 2000 cycles for supercapacitor. These results show a great application in large-scale energy storage.

Synthesis, characterization, and cytotoxicity of self-assembly of hybrid nanocomposite modified membrane of carboxymethyl cellulose/graphene oxide for photocatalytic antifouling, energy storage, and supercapacitors application

In this work, carboxymethylcellulose (CMC) macrostructure has been incorporated with graphene oxide nanosheet (GO) to form a hybrid composite as a modified surface for antifouling membrane and supercapacitor applications. The hybrid nanomaterial (HNM) has been synthesized successfully and characterized via various tools, such as scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-Vis), and X-ray diffraction (XRD). A modified surface of Graphene oxide/ Cellulose (GO@CMC) has been studied by cyclic voltammetry technique for detecting the electrochemical properties, supercapacitor, and energy storage. Also, the optical properties of the modified antifouling surface of the HNM membrane were detected by UV-spectroscopy apparatus for water treatment applications. For proving the easily, the electron transfer of GO@CMC via the photocatalytic process for degradation of organic and inorganic pollutions, such as methylene blue (MB) dye. The cytotoxicity of fabricated HNM has been studied with two cell lines such as Breast Cancer cell line (MDA-MB-231) and the other was Hepatocellular carcinoma cell line (HepG2), the following results have been obtained: - A good electron transfer has been detected with GO@CMC HNM. - Easily the photocatalytic process with organic compounds pollution. - GO@CMC HNM has effects observably on the cell lines of MDA-MB-231 and HepG2. - Results demonstrated that the fabricated HNM is promising electrode material for supercapacitors application and energy storage.

Ultrathin MoSe2 nanosheets decorated on carbon aerogel microspheres for high-capacity supercapacitor electrodes

A new MoSe 2 /CRF electrode was successfully constructed, which possessed enhanced specific capacitance and high cycling stability via the synergistic effect of MoSe 2 nanosheets and carbon aerogel microspheres. • MoSe 2 nanosheets and carbon aerogel microspheres hybrid via solvent-thermal method was prepared. • MoSe 2 NSs/CRF electrode exhibits an excellent specific capacitance and a high cycling stability. • Porous carbon aerogel microspheres restrict the aggregation of MoSe 2 nanosheets. • MoSe 2 NSs/CRF has potential as an electrode material in supercapacitor fields. Two-dimensional layered molybdenum selenide nanosheets have been a promising electrode material for electrochemical energy storage because of their high theoretical capacitance. However, the intrinsic low electrical conductivity and inferior structural stability impede its real application. Herein, MoSe 2 nanosheets are incorporated into carbon aerogel microspheres (MoSe 2 NSs/CRF) via a facile solvent-thermal method. The specific surface area and electric conductivity of the MoSe 2 NSs/CRF electrode were increased simultaneously because of its incorporation with porous carbon aerogel microspheres. As a result, the MoSe 2 NSs/CRF electrode exhibits an excellent specific capacitance of 498F g −1 at a current density of 1 A g −1 , which is 3 times higher than that (136F g −1 ) of the pristine MoSe 2 nanosheets. With a 5-fold increase to 5 A g −1 , it still retains 278F g -1 and high cycling stability of 127.2% of the initial retention after 2500 cycles at 100 mV s −1 . Moreover, we fabricated a symmetric supercapacitor (SC) using a composite composed of MoSe 2 NSs/CRF. The symmetric supercapacitor showed capacitance of 124F g −1 with an energy density of 8.5 W h Kg −1 at a power density of 264.8 W Kg −1 at a current density of 1 A g −1 . The superior electrochemical performances demonstrating that the MoSe 2 NSs/CRF has potential as an electrode material for energy storage application in high-performance supercapacitor fields.

PAN/lignin and LaMnO3-derived hybrid nanofibers for self-standing high-performance energy storage electrode materials

PAN/lignin and LaMnO3-derived hybrid nanofibers for self-standing high-performance energy storage electrode materials