Anode Material For Applications Research Articles

Simultaneous engineering of the conductivity and work function of biphenylene via fluorine adsorption

Biphenylene (BP) is a new member of the two-dimensional C nanomaterial family, and successful fabrication of BP offers an excellent opportunity for developing innovative C-based electronics. However, its unusual metallicity critically restricts its applications in field-effect transistors (FETs) and photocatalysis. Simultaneously, its relatively low work function (ϕ, 4.33 eV) seriously restricts its applications in anode materials of electronic devices. Therefore, understanding the tunabilities of electronic properties and ϕ of BP-based nanomaterials is crucial to guide experimental exploration; nevertheless, to date, little attention has been paid to this area. Herein, we theoretically demonstrate that conductivity of fluorinated BP (Fn-BP) evolves in the order metallic → semimetallic → semiconductivity with increasing F concentration, attributed to a bonding transition of BP (sp2 → sp2 + sp3 → sp3). Particularly, ϕ of BP can be significantly improved (4.82–6.97 eV) by fluorination, approximately two-fold higher than that of Fn-graphene owing to p electron transfer between F and BP. Consequently, metallic F2D-BP and semimetallic F4S-BP with favorable ϕs can be utilized as substitutes for Au and Pt anodes, respectively. Specifically, F8D-BP, F16D-BP, and F24D-BP with exceptional band gaps of 0.40, 2.80, and 3.44 eV, respectively, exhibit high potentials for making channel materials in FETs, candidate materials in photocatalysis, and buffer layers in solar cells, respectively.

Controlling the structural features of tin dioxide nanoparticles embedded reduced graphene oxide on carbon cloth to serve as high stability fast charging anode for Li-ion cells

Tin dioxide or stannic oxide (SnO2) is an n-type semiconductor that has profound applications in gas sensors, solar cells, and energy storage devices like Li-ion batteries. Due to their high theoretical capacity (1494 mAh g−1) affordability, eco-friendliness, and safe operating conditions, SnO2 based anode materials are being extensively studied. Electrochemical capacity and stability for energy storage can be enhanced by embedding facet exposed SnO2 nanoparticles in reduced graphene oxide (rGO). In this study, SnO2 nanoparticles are synthesized and incorporated into rGO network via a simple solvo-thermal method is applied onto a carbon cloth substrate and used as anode for SnO2/rGO based Li-ion cell. The initial discharge capacity is found to be 1415 mAh g−1 and the charge capacity to be 1236 mAh g−1 with an initial Coulombic efficiency of 87 % at a current rate of 0.1 A g−1. The cell also exhibits excellent cycling stability and rate capability, with a discharge capacity of 1034 mAh g−1 and a charge capacity of 998 mAh g−1 at a current rate of 0.3 A g−1. This electrode is stable at a higher current rate of 2C (3 A g−1) and hence offers high prospects as anode material for application in fast-charging rechargeable cells.

Dual Design on Hierarchically Hollow MoTe2/C with Ion/Electron Channel Engineering for High-Performance Sodium Storage.

Transition-metal tellurides have been investigated as novel anode materials for application in sodium-ion batteries (SIBs) due to their rich active sites and unique and controllable layered nanostructures. However, the weak structural strength and inferior intercalation/deintercalation kinetics inhibit the development of transition-metal tellurides. In this work, MoTe2/C composites with two different hollow nanostructures are designed and prepared. By adjustment of the precursor structure, MoTe2/C-2 exhibits superior sodium-storage performance because of its uniquely hollow nanostructure with self-assembled 2D flexible nanosheets grown on the external surface. MoTe2/C-2 delivers a higher specific capacity (276 mAh g-1 at 0.1 A g-1 after 300 cycles), much more than MoTe2/C-1 (201 mAh g-1 at 0.1 A g-1 after 300 cycles), and exhibits a long-time cycling performance (131 mAh g-1 at 1 A g-1 after 2000 cycles). The excellent sodium-storage performance derived from the rational structure design is beneficial for shortening the ion paths, facilitating the sodiation/desodiation process, and reinforcing the intrinsic structural stability, thus boosting the reaction kinetics and prolonging the cycling life. Meanwhile, the assembled full-cell maintains 101 mAh g-1 at 0.1 A g-1 after 50 cycles and lights an electric watch. The findings provide several new views for preparation of more transition-metal tellurides with multi-ion/electron migration channel engineering.

Phosphorous/Fluorine Co‐doped Biomass‐derived Carbon for Enhanced Sodium‐ion and Lithium‐ion Storage

AbstractCarbon from inexpensive biomass‐based precursors have shown promise as anode materials for application in sodium/lithium ion battery technology. However, their practical implementation is marred by unreliable cycling stability and unimpressive initial coulombic efficiency. The electrochemical properties of such biomass derived carbon can be improved considerably by material engineering via suitable heteroatom doping. In this work, the effect of phosphorous and fluorine doping on naseberry seed derived carbon has been explored. The doping led to an increase in the specific capacity and rate performance of the modified bio‐based carbon in comparison to non‐doped counterparts. The P/F incorporated carbon delivers reversible capacity of 812 mAh g−1 and 409 mAh g−1 at 0.1 A g−1 when tested as anode in lithium/sodium ion coin cell. The long term cycling of the material at a higher current rate of 1.0 A g−1 is also impressive. The reason for this enhanced electrochemical performance has been analysed through electrochemical impedance spectroscopy and post mortem electron microscopic studies. The increase in interlayer spacing, cell volume and ionic conductivity in the P/F incorporated carbon which leads to an improvement in the electrochemical properties has also been corroborated via DFT analysis.

A Novel Membrane-like 2D A'-MoS2 as Anode for Lithium- and Sodium-Ion Batteries.

Currently, new nanomaterials for high-capacity lithium-ion batteries (LIBs) and sodium- ion batteries (SIBs) are urgently needed. Materials combining porous structure (such as representatives of metal-organic frameworks) and the ability to operate both with lithium and sodium (such as transition-metal dichalcogenides) are of particular interest. Our work reports the computational modelling of a new A'-MoS2 structure and its application in LIBs and SIBs. The A'-MoS2 monolayer was dynamically stable and exhibited semiconducting properties with an indirect band gap of 0.74 eV. A large surface area, together with the presence of pores resulted in a high capacity of the A'-MoS2 equal to ~391 mAg-1 at maximum filling for both Li and Na atoms. High adsorption energies and small values of diffusion barriers indicate that the A'-MoS2 is promising in the application of anode material in LIBs and SIBs.

Regulating the Electronic Configuration of Spinel Zinc Manganate Derived from Metal-Organic Frameworks: Controlled Synthesis and Application in Anode Materials for Lithium-Ion Batteries.

In recent years, transition metal oxides have been considered as the most promising anode materials due to their high theoretical capacity, low price, and abundant natural reserves. Among them, zinc manganate is used as an electrode material for anodes, whose application is mostly hindered due to its poor ionic/electronic conductivity. In this work, a series of ZnMn2O4 (ZMO) are synthesized by a hydrothermal technique coordinated with a metal-organic framework-based high-temperature calcination process for their application as an anode in lithium-ion batteries (LIBs). Meanwhile, this study systematically explores the influence of carbon doping and the types of organic ligands and oxygen vacancies on the electrochemical properties of the synthesized ZMO. Density functional theory (DFT) calculations and experimental investigations reveal that the introduction of carbon and oxygen vacancies can enhance electronic conductivity, more active sites and faster Li+ adsorption, resulting in better electrochemical performances. As expected, all ZMOs with carbon doping (PMA-ZMO, MI-ZMO, and BDC-ZMO) derived from 1,2,4,5-benzenetetracarboxylic acid, 2-methylimidazole, and 1,4-dicarboxybenzene achieve outstanding electrochemical performance. Meanwhile, the introduction of oxygen vacancies can enhance the electronic conductivity and can significantly reduce the activation energy of Li+ transport, thereby accelerating the Li+ diffusion kinetics in the lithiation/delithiation process. Furthermore, an optimal ZMO anode material synthesized by 2-methylimidazole delivers a high reversible capacity of 1174.7 mA h g-1 after 300 cycles at 0.1 A g-1 and 600 mA h g-1 at 0.5 A g-1 after 300 cycles. After high-rate charge and discharge cycles, the specific capacity rapidly recovers to a value greater than the initial value, which proves the unusual activation and thereby an excellent rate property of the electrode. Hence, we conclude that ZMO provides potential application prospects as an anode electrode material for LIBs.

Promoting the performances of NaTi2(PO4)3@C porous composite as novel anode materials for application in sodium ion battery

Rechargeable aqueous sodium-ion batteries (SIBs) are urgently pursued as a low-cost candidate for grid-scale storage of intermittent renewable energies. NASICON-type NaTi2(PO4)3 holds great promises as anode material for aqueous SIBs owing to the high theoretical capacity and low redox potential, but being severely challenged by poor cycling performance and low reaction kinetics. In this study, a porous carbon-decorated NaTi2(PO4)3 composite was made using a simple sol-gel method and then thermally treated. The NaTi2(PO4)3 particles are adhered to the surface of carbon sheets uniformly. The NTP@C electrode delivers a reversible capacity of 198.1 mAhg−1 at 0.2 C, which is much higher than NTP (125.5 mAhg−1). Atta 50 cycle, a capacity of 196.5 mAhg−1 can be obtained for the NTP@C composite, which in about 99.1% of its initial capacity. From the EIS, RCT value of NTP@C was estimated to be 51.32 Ὠ which is lower than that of bar NTP (78.2 Ὠ). Carbon greatly improves the cell's performance, particularly the cycle lifetime at high charge-discharge rates of NTP electrodes. The increased structural stability and electron/Na + ion transfer kinetics of the NTP@C anode material are responsible for its exceptional electrochemical properties and long cycle lifespan.

Progress in electrolyte and interface of hard carbon and graphite anode for sodium‐ion battery

AbstractIt is essential to replace lithium‐ion batteries (LIBs) from the perspective of the Earth's resources and the sustainable development of mankind. Sodium‐ion batteries (SIBs) are important candidates due to their low price and abundant storage capacity. Hard carbon (HC) and graphite have important applications in anode materials of SIBs. In this review, the research progress in electrolyte and interface between HC and graphite anode for SIBs is summarized. The properties and performance of three types of widely used electrolytes (carbonate ester, ether, and ionic liquid) with additives, as well as the formation of solid electrolyte interface (SEI), which are crucial to the reversible capacity and rate capability of HC anodes, are also discussed. In this review, the co‐intercalation performance and mechanism of solvation Na+ into graphite are summarized. Besides, the faced challenges and existing problems in this field are also succinctly highlighted.

Facile synthesis and electrochemical evaluation characteristics of NiO-CeO2 based inorganic nanocomposite anode material for application in LTSOFC

In this research work, we report the synthesis and characterization of NiO-Ce0.95Nd0.05O2-δ-Ce0.95Gd0.05O2-δ (NiO-CNO-CGO) nanocomposite anode material for LTSOFC. The thermal properties of NiO-CNO-CGO precursor were studied using TGA-DSC analysis which inferred that the formation of pure-phase was completed at around 600 °C. XRD analysis reveals a single fluorite cubic phase structure. FTIR data confirmed the occurrence of stretching vibration of M-O bond in the sample. Presence of nano-sized particles was confirmed by particle size analysis. The surface morphology was studied using SEM resulting in unsmooth grains. Respective atomic weight percentage of Ni, Ce, Nd, Gd and O was confirmed by EDAX studies. The surface roughness was studied using AFM. The sample resulted in a conductance of 4.55 x 10−4 Scm−1 in air atmosphere with activation energy of 0.4483 eV. The obtained results were discussed in order to use the material as an efficient anode for LTSOFC application.

Synthesis of carbon-SiO2 hybrid layer @ SiO2 @ CNT coaxial nanotube and its application in lithium storage

To alleviate the volume variation upon the silicon oxide during the lithium ion storage process and improve its cyclic stability as well as rate performance in the application of anode material in LIBs, a silicon oxide, carbon and carbon nanotube hybrid material with coaxial structure is developed here in a two-step manner. The formed Carbon-SiO2@SiO2@CNT coaxial nanotube material carries 644 mAh g−1 stable capacity under 0.1 A g−1 as the anode material in LIBs. After over 5000 operating cycles under 1 A g−1, 242 mAh g−1 reversible capacity is clearly demonstrated. The enhanced electrochemical performances can be mostly attributed to the inner carbon nanotube and outer carbon layer, both of which can relief the stress arising from the change of volume and improve the conductivity. The coaxial structure may also benefit to the lithium ions transportation.

Recycling Iron-Containing Sludges from the Electroflocculation of Printing and Dyeing Wastewater into Anode Materials for Lithium-Ion Batteries.

Iron-containing sludges (DW/Fe) were prepared by the electroflocculation of industrial printing and dyeing wastewater (DW). To investigate the formation process and the properties of the DW/Fe sludges and their application in anode materials in Li-ion batteries, the DW/Fe sludges were compared to three other sludges (MB/Fe, RB/Fe, Ta/Fe) prepared from model solutions that contained either methyl blue (MB), rhodamine B (RB), or tartrazine (Ta). The DW/Fe sludges were calcined at 500 °C under N2 to form iron oxide/carbon composite C-DW/Fe. The composition and structure of the sludges and the C-DW/Fe composite were analyzed by using FTIR spectroscopy, XRD, thermogravimetric analysis, SEM, TEM, and X-ray photoelectron spectroscopy, and their performances as anodes of Li-ion batteries were studied by adding different proportions of conductive agent (super P® conductive carbon black). Our results show that the sludges are a complex mixture of Fe3 O4 and organic matter. The specific capacity and stability can be improved during the charge-discharge test by increasing the amount of carbon black. Importantly, this improvement is more pronounced on DW/Fe that does not require high-temperature carbonization, which means that the sludges cannot only protect the environment and avoid the waste of resources but also can be used directly and widely in decentralized energy storage devices.

SiOx-based (0 < x ≤ 2) composites for lithium-ion batteries

Silicon (Si) materials as anode materials for applications in lithium-ion batteries (LIBs) have received increasing attention. Among the Si materials, the electrochemical properties of SiOx-based (0 < x ≤ 2) composites are the most prominent. However, due to the cycling stability of SiOx being far from practical, there are some problems, such as low initial coulombic efficiency (ICE), obvious volume expansion and poor conductivity. Researchers in various countries have optimized the electrochemical properties of SiOx-based composites by means of pore formation, surface modification, and the choice of constituents. In this review, SiOx-based composites are classified into three categories based on the valency of Si (SiO2 composites, SiO composites and SiOx (0 < x < 2) composites). The synthesis, morphologies and electrochemical properties of the SiOx-based composites that are applied in LIB are discussed. Finally, the properties of several common SiOx-based composites are briefly compared and the challenges faced by SiOx-based composites are highlight.

Silicon anodes for lithium-ion batteries produced from recovered kerf powders

Silicon kerf waste from a photovoltaic silicon production process is assessed as an anode material for application as a lithium ion battery anode. In contrast to previous studies, the Si-kerf is used as-produced, with no chemical treatment or physical processing beyond solvent PEG removal. The as-produced Si-kerf performed as well as, or better than, previously reported Si-kerf anodes and is found to outperform a cleaned Si-kerf sample from blade sawing with a larger particle size. This highlights the advantage of the diamond wire cutting process, which yields relatively small particles. In half-cell testing, a cycle life >300 cycles at a capacity of 1000 mAh g−1 is achieved with high levels of FEC addition. Full-cell testing against an NMC 442 cathode resulted in specific capacities up to 150 mAh g−1 (NMC). A relatively high degree of lithium consumption arising from repeated SEI formation is present. It is concluded that pure Si-kerf is unsuitable for commercial application in Li-ion cells.

Carbon-Encapsulated Sn@N-Doped Carbon Nanotubes as Anode Materials for Application in SIBs.

Carbon-encapsulated Sn@N-doped carbon tubes with submicron diameters were obtained via the simple reduction of C@SnO2@N-doped carbon composites that were fabricated by a hydrothermal approach. Sn nanoparticles encapsulated in carbon layers were distributed uniformly on the surfaces of the N-doped carbon nanotubes. The electrochemical performances of the composites were systematically investigated as anode materials in sodium-ion batteries (SIBs). The composite electrode could attain a good reversible capacity of 398.4 mAh g-1 when discharging at 100 mA g-1, with capacity retention of 67.3% and very high Coulombic efficiency of 99.7% over 150 cycles. This good cycling performance, when compared to only 17.5 mAh g-1 delivered by bare Sn particles prepared via the same method without the presence of N-doped carbon, could be mainly ascribed to the uniform distribution of the precursor SnO2 on the substrate of N-doped carbon tubes with three-dimensional structure, which provides more reaction sites to reduce the diffusion distance of Na+, further facilitating Na+-ion diffusion and relieves the huge volume expansion during charging/discharging. These outcomes imply that such a Sn/C composite would provide more options as an anode candidate for SIBs.

Fast facile synthesis of SnO2/Graphene composite assisted by microwave as anode material for lithium-ion batteries

SnO2 is promising as anode material for Lithium ion batteries(LIBs) due to its high specific capacity and low opening potential. However, its poor electronic conductivity as well as serious volume effect significantly restrict its application in LIBs. In this work, a facile hydrothermal method assisted with microwave is performed to realize the composite of SnO2 and graphene within only 30minutes without any chelating agents. It is highly time-efficient with relatively high SnO2 loading of 89.97wt.%. Ultrasmall nano-particles of SnO2 well disperse on the surface of the graphene with average particle size of 3–8nm and larger surface area of 417.45m2g−1. Simultaneously, high charge/discharge capacity of 969.4/978.6mAhg−1 is obtained after 100 cycles at 200mAg−1. Even increasing the current density to 1Ag−1, high reversible charge/discharge capacities of 740.0/747.0mAhg−1 are still remained after 200 cycles. In addition, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are performed to further study the composite material prepared by facile microwave hydrothermal method. It is considered to be a high efficient way to obtain SnO2/graphene composite with excellent electrochemical properties as anode material for applications.

Rapid Microwave Synthesis of Self-Assembled Hierarchical Mn2O3 Microspheres as Advanced Anode Material for Lithium Ion Batteries

Rapid microwave hydrothermal synthesis is carried out to obtain hierarchical Mn2O3 microsphere through a self-assembled process within 30minutes. All the raw materials used is nontoxicity without any template or polymer and the side-products are all small molecules which abide by the pricnciple of environmental protection. After the following solid state reaction, the as-prepared Mn2O3 powders can still keep the hierarchical morphology of micro sphere which is consisted of small primary particles and secondary slices. The sample obtained at 600°C with high crystallinity, large specific surface area and mesoporous exhibits best electrochemical performances. High specific capacity of 921.6mAhg−1 could be reached at a current density of 200mAg−1. An interesting phenomenon with abnormal capacity increasing appears which could be ascribed to the continual enhancement of interface Li-storage. Thus, high specific capacity of about 525mAhg−1 is obtained at high current density of 1000mAg−1 after 500 cycles. Furthermore, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are performed to further study the hierarchical Mn2O3 anode material. It is revealed that such rapid microwave synthesis without any contamination is considered as a promising way to obtain hierarchical manganese oxides as anode material for applications.

ChemInform Abstract: Cu3V2O8 Nanoparticles as Intercalation‐Type Anode Material for Lithium‐Ion Batteries.

AbstractCu3V2O8 nanoparticles (40‐50 nm) are prepared by addition of NH4VO3 to an aqueous 0.1 M Cu(NO3)2 solution followed by drying and sintering of the Cu3V2O7 (OH)2·2H2O precipitate in air (400 °C, 1 h).

Cu3 V2 O8 Nanoparticles as Intercalation-Type Anode Material for Lithium-Ion Batteries.

Cu3 V2 O8 nanoparticles with particle sizes of 40-50 nm have been prepared by the co-precipitation method. The Cu3 V2 O8 electrode delivers a discharge capacity of 462 mA h g(-1) for the first 10 cycles and then the specific capacity, surprisingly, increases to 773 mA h g(-1) after 50 cycles, possibly as a result of extra lithium interfacial storage through the reversible formation/decomposition of a solid electrolyte interface (SEI) film. In addition, the electrode shows good rate capability with discharge capacities of 218 mA h g(-1) under current densities of 1000 mA g(-1) . Moreover, the lithium storage mechanism for Cu3 V2 O8 nanoparticles is explained on the basis of ex situ X-ray diffraction data and high-resolution transmission electron microscopy analyses at different charge/discharge depths. It was evidenced that Cu3 V2 O8 decomposes into copper metal and Li3 VO4 on being initially discharged to 0.01 V, and the Li3 VO4 is then likely to act as the host for lithium ions in subsequent cycles by means of the intercalation mechanism. Such an "in situ" compositing phenomenon during the electrochemical processes is novel and provides a very useful insight into the design of new anode materials for application in lithium-ion batteries.

Nanoplate and mulberry-like porous shape of CuO as anode materials for secondary lithium ion battery

Facile hydrothermal synthesis of nanoplate and mulberry-like porous shape of CuO nanostructures was developed as anode materials for application in lithium ion batteries. The powder X-ray diffraction patterns of both the samples were indexed well to a pure monoclinic phase of CuO with no impurities. The CuO sample synthesized at different pH and reaction temperature exhibited nanoplate with average width and length of ∼150–300nm and ∼300–700nm and mulberry-like porous shape of CuO with average length of ∼300–400nm. Electrochemical tests show that the lithium storage performances of both the nanoplate and mulberry-like samples are influenced more closely to its structural aspects than their morphology and size factors. The CuO nanoplate electrode exhibits high reversible charge capacity of 279.3mAhg−1 at 1.0C after 70 cycles, and a capacity of 150.2mAhg−1 even at high current rate of 4.0C during rate test, whereas the mulberry-like porous shape of CuO anode delivers only 131.4mAhg−1 at 1.0C after 70 cycles and 121.7mAhg−1 at 4.0C. It is believed that the nanoplate type architecture is very favorable to accommodate the volume expansion/contraction and aggregation of particles during the cyclic process. In contrast, the mulberry-like porous morphology could not preserve the integrity of the structure and completely disintegrated into nanoparticles during Li+ ion insertion/deinsertion due to the loose contact between the particles.

Highly Ordered Mesoporous Si/C Nanocomposite as High Performance Anode Material for Li-ion Batteries

Highly ordered mesoporous Si/C (OMP-Si/C) anode composite for lithium ion battery is fabricated by a moderate magnesiothermic reduction and carbon coating using SBA-15 as a precursor. The synthesized OMP-Si/C composite rods preserve the original nanostructure of ordered honeycomb pore channels in SBA-15 and link one by one to form lotus-root-like chains which tightly agglutinate into bundles with a high packing density. A liquid ambient reaction model is also proposed to describe the reaction mechanism between SBA-15 and magnesium powder and the formation of this unusual highly ordered mesoporous structure at temperature of 660°C. The samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption, and Raman spectroscopy. The highly ordered mesoporous structure provides buffering space to accommodate the large volume expansion/contraction and consequent stress induced inside silicon during Li+ insertion/extraction. Furthermore, this mesoporous structure can also provide transportation routes for electrolyte and shorten the diffusion paths for lithium ions. The carbon coating on mesoporous silicon can provide electronically conductive networks for the electrode. These effectively mitigate silicon pulverization issue and help achieve higher reversible capacity and better capacity retention. The excellent electrochemical performance of this highly ordered mesoporous Si/C shows its promising applications in anode materials for Li-ion batteries.