Performance Anodes For Lithium-ion Batteries Research Articles

MoO2 nanobelts modified with an MOF-derived carbon layer for high performance lithium-ion battery anodes

Molybdenum oxide (MoO2) is a promising anode material for use in lithium-ion batteries because of its high theoretical capacity (838 mAh g−1). However, rapid capacity decay seriously restricts its practical application. In this work, MoO2 nanobelts were coated in situ with a metal-organic framework (MOF)-derived carbon layer to construct a MoO2@C composite through a facile solvothermal method combined with an annealing treatment to generate high performance lithium-ion battery anodes. Such a composite has a novel core-shell structure with MoO2 nanobelts as the core and an MOF-derived carbon layer as the shell. The MOF-derived carbon layer, which is composed of numerous N-doping carbon nanoparticles immersed with cobalt monoxide (CoO) nanoparticles, is quite thin, with a thickness of ∼7–8 nm, and it possesses many pores. When evaluated as anode material for lithium-ion batteries, the MoO2@C electrode exhibits outstanding electrochemical performance, including a high specific capacity of 1049 mAh g−1 at 0.1 A g−1 for the 50th cycle, superior rate capability of 710 mAh g−1 at 5 A g−1 (68% retention of the capacity at 0.1 A g−1) and excellent cycling stability of 787.7 mAh g−1 at 1 A g−1 after 300 cycles (96% capacity retention). These results are mainly attributed to the multifunctionality of the MOF-derived carbon layer, which realizes an effective synergistic effect of high conductivity, enhanced reaction kinetics, stable microstructure and extra capacity contribution from the CoO component. Therefore, this work expands the application of MOFs and provides a promising method for developing an MoO2 anode material for next-generation lithium-ion batteries.

CuO ultrathin nanosheets decorated reduced graphene oxide as a high performance anode for lithium-ion batteries

Two-dimensional (2D) nanocomposites, based on graphene and transition metal oxides, hold great promise as high-performance electrode materials for next-generation lithium-ion batteries. Herein, a novel 2D CuO/RGO has been constructed by CuO ultrathin nanosheets and reduced graphene oxides (RGO) through in-situ oxidizing the Cu/RGO nanocomposite with hydrogen peroxide. CuO nanosheets with a thickness of 1.17–1.57 nm are uniformly and tightly anchored on the RGO surface without aggregation and thus the as-prepared CuO/RGO nanosheets electrode show strong interfacial coupling and fast electron transfer. Electrochemical characterizations reveal that the CuO/RGO nanocomposite electrode exhibits a remarkably enhanced cycling performance and rate performance. At the current density of 0.1C, the initial discharge capacity of 811 mAh/g has been delivered by CuO/RGO nanosheets electrode and the coulombic efficiency maintains 99.44% after 100 cycles. Moreover, the CuO/RGO nanosheets exhibit a stable specific capacity of 386 mAh/g after 200 cycles at 3C. In addition, the as-prepared CuO/RGO nanocomposite electrode exhibited excellent rate performance and lower charge transfer resistance. The current study presents a feasible route to fabricate nanosheets electrode materials for next-generation energy storage devices.

New Hexagonally Ordered Monolayer Electrode with Monodisperse Carbon/Fe3O4 Microspheres for High Performance Lithium Ion Battery Anodes

This work details the facile preparation of a hexagonally ordered monolayer electrode with monodispersed hollow C/Fe3O4 microspheres as a novel anode candidate for lithium-ion batteries. The monolayer electrode was produced by the heat treatment of a polyvinyl alcohol film comprising a monolayer of microspheres. The electrode was prepared by stamping with microspheres assembled into the monolayer, using an ordered patterning micro-framework polydimethylsiloxane on a polyvinyl alcohol spin-coated cupper foil. The morphological and structural characterizations of the monolayer electrode were conducted by optical microscopy, scanning electron microscopy, focused-ion beam scanning electron microscopy, transmission electron microscopy, and X-ray diffractometery. Although the monolayer electrode was composed of the active materials only without the use of any polymeric binder or carbon additives such as acetylene black and Super-P, the electrode exhibited a superior long-term cycling stability and rate capability with the coulombic efficiency of 99% at a high current rate due to the good structural stability and low electrical resistance as a result of the ordered monolayer structure.

One-dimensional architecture with reduced graphene oxide supporting ultrathin MoO2 nanosheets as high performance anodes for lithium-ion batteries

Two-dimensional (2D) materials have been widely studied and used as anode materials for lithium ion batteries (LIBs) because of their high specific surface area and intrinsic mechanical flexibility which could offer numerous active sites and protect effect for LIBs. However, 2D nanosheets are easy to stack and partially lose surface area for Li-ion storage thus greatly affecting their electrochemical performance. Here, we develop a simple strategy to obtain a nanosheets-based one-dimensional structure hybrid by in situ reduction from MoO3 nanorods to MoO2 nanosheets and nanoparticles which are anchored on a 1D reduced graphene oxide skeleton (MoO2-rGO). It was demonstrated that the primary MoO2 nanosheets and nanoparticles are uniformly dispersed on the reduced graphene oxide nanosheets, which are further assembled into a 1D loosened nanostructure. The loosened nanosheets offer more accessible surface area and facilitate transport of electrons and Li-ions. Moreover, MoO2 nanoparticles effectively avoid agglomeration from nanosheets. Results show that MoO2-rGO hybrid demonstrates an enhanced cyclic life, high stability and prominent rate performance when evaluated as anode material for LIBs. The first discharge capacity can reach 1256.4 mAh g−1 and provide a highly reversible capacity of 1003.7 mA h g−1 after 100 cycles at 0.1 A g−1, which makes MoO2-rGO a promising candidate for LIBs. The excellent performance can be attributed to the unique 1D loosened structure consists of MoO2 and conducting rGO nanosheets, which facilitates fast transfer of Li-ion and electron, and the reduced graphene oxide nanosheets acting as a skeleton provide a continuous conductive network and simultaneously strengthen the structural stability.

Porous ZnO/Co3O4/CoO/Co composite derived from Zn-Co-ZIF as improved performance anodes for lithium-ion batteries

Micro-nanostructure metal oxides derived from metal organic frameworks had attracted widely attention due to their potential application in high energy density lithium ion batteries. In this work, ZnO/Co3O4/CoO/Co composite materials were successfully synthesized by a facile approach through calcination of preformed Zn-Co-ZIF precursor and tested as anode materials for lithium ion batteries. This porous composite materials exhibit superior lithium storage capabilities with good cycling stability and rate capability. It demonstrates a reversible capacity (972.6 mA h g−1 at 100 mA g−1 after 100 cycles), excellent rate capability (681.2 mA h g−1 at 1000 mA g−1). The enhanced electrochemical performance of the porous ZnO/Co3O4/CoO/Co hybrid composite materials can be ascribed to the synergetic effect of multi-component functional micro/nanoparticles systems.

Hollow Co2SiO4 microcube with amorphous structure as anode material for construction of high performance lithium ion battery

To solve the problem of large volume expansion of cobalt silicate electrode during cyclic process and low electric conductivity, Co2SiO4 with amorphous, porous and hollow structure is firstly designed to act as high performance lithium ion battery (LIB) anode. Compared with crystalline materials, the amorphous Co2SiO4 microcube could facilitate Li+ diffusion to enhance their performance of LIBs because of isotropic characteristics. Here, the amorphous Co2SiO4 hollow microcube (named as a-Co2SiO4 HC) was prepared by mild hydrothermal method with use of MnCO3 microcube as hard-template. Benefitting from the advantages of such structure, Li+ diffusion rate was greatly accelerated and the volume expansion can be alleviated. The as-prepared amorphous Co2SiO4 hollow microcube as anode material of LIBs exhibited significantly improved electrochemical performance of 610 mAh g−1 even after 380 cycles at 500 mAh g−1 than their crystalline counterpart (only 280 mAh g−1 retained after 380 cycles). This work is a good try to employ amorphous metal silicate in LIBs and simultaneously motivate the exploration of other amorphous materials for high performance LIBs, SIBs, catalysts, etc.

In-situ growth of binder-free hierarchical carbon coated CoSe2 as a high performance lithium ion battery anode

Transition metal selenides have been regarded as promising materials for lithium ion batteries but still face great challenges, including poor rate performance and unsatisfactory cycling stability. Herein, flexible hierarchical carbon coated CoSe2 electrode was rationally designed and synthesized for LIBs and demonstrates a high capacity of 638.3 mAh/g, very good rate capability, and excellent cycling stability of 100% after 100 cycles. The impressive electrochemical performance is attributed to the binder-free nanostructured electrode architecture and the carbon coating, which not only highly improves the electric conductivity but also alleviates the volumetric expansion/shrinkage during lithiation/delithiation. This work displays a good case for developing high performance lithium ion battery electrodes based on conversion materials.

Large-scale synthesis of NiS@N and S co-doped carbon mesoporous tubule as high performance anode for lithium-ion battery

The simple and large-scale synthesis of metal sulfides@heteroatom-doped carbon tubules with high lithium storage performance is seldom reported. In this work, mesoporous NiS@N and S co-doped carbon (NiS@NSC) tubules were firstly prepared by nickel salt impregnation and subsequently calcination using absorbent cotton as template. The crystalline NiS nanoparticles with an average particle size of about 90 nm are uniformly embedded in the mesoporous tubular N and S co-doped carbon skeleton. The BET specific surface area is 200.8 m2 g−1 and the uniform narrow mesopore size distributes centered at 2.32 nm. As anode for lithium-ion batteries, it displays good cycling stability and rate capability, which retains a reversible capacity of 715.9 mA h g−1 after 200 cycles at 0.1 A g−1, and even at a high current density of 5 A g−1 the specific discharge capacity can retain 411.1 mA h g−1, which is higher than for most of the reported NiS@C composites. The good electrochemical performances are mainly attributed to the inherent characteristics of NiS@NSC hollow tubules, involving uniform mesopores, large specific surface area and highly conductive N and S co-doped carbon skeleton.

Lamellarly Stacking Porous N, P Co-Doped Mo2 C/C Nanosheets as High Performance Anode for Lithium-Ion Batteries.

Layered stacking and highly porous N, P co-doped Mo2 C/C nanosheets are prepared from a stable Mo-enhanced hydrogel. The hydrogel is formed through the ultrafast cross-linking of phosphomolybdic acid and chitosan. During the reduction of the composite hydrogel framework under inert gas protection, highly porous N and P co-doped carbon nanosheets are produced with the in situ formation of ultrafine Mo2 C nanoparticles highly distributed throughout the nanosheets which are entangled via a hierarchical lamellar infrastructure. This unique architecture of the N, P co-doped Mo2 C/C nanosheets tremendously promote the electrochemical activity and operate stability with high specific capacity and extremely stable cycling. In particular, this versatile synthetic strategy can also be extended to other polyoxometalate (such as phosphotungstic acid) to provide greater opportunities for the controlled fabrication of novel hierarchical nanostructures for next-generation high performance energy storage applications.

Aqueous binder effects of poly(acrylic acid) and carboxy methylated cellulose on anode performance in lithium-ion batteries

The aqueous binder effects of poly(acrylic acid) and carboxy methylated cellulose on metal (oxide) anode performance in lithium-ion batteries were studied.

A sandwich-like Si/SiC/nanographite sheet as a high performance anode for lithium-ion batteries.

Silicon/carbon (Si/C) nanocomposite anodes have attracted great interest for their use in lithium-ion batteries (LIBs). However, Si nanoparticles are difficult to stabilize on a carbon surface. Herein, we solve this stabilization problem by designing a Si/silicon carbide/nanographite sheet (Si/SiC/NanoG) nanocomposite. The Si/SiC/NanoG nanocomposite is synthesized by the magnesium thermal reduction of a mixture of silica (SiO2) nanoparticles and NanoG at low temperature, which results in a sandwich-like structure in which the middle SiC layer serves as a linker to stabilize the Si nanoparticles on the surface of NanoGs. Electrochemical characterization shows that the Si/SiC/NanoG nanocomposite anode exhibits outstanding electrochemical performance (an initial reversible capacity of 1135.4 mA h g-1 and 80.4% capacity retention after 100 cycles at 100 mA g-1). This high capacity retention is due to the strong connection between Si and NanoG through the interfacial SiC layer, which buffers the volume changes during the Li-Si alloying-dealloying process. This research will contribute to the design of advanced Si/C anode materials of LIBs.

Hybrid Carbon Nanotube Fabrics with Sacrificial Nanofibers for Flexible High Performance Lithium-Ion Battery Anodes

Silicon is one of the most promising anode materials for lithium-ion batteries because of its highest known theoretical charge capacity (4,200 mAh g−1). However, it has found limited application in commercial batteries because of the significant volume change (up to 400%) of silicon during cycling, which results in pulverization and capacity fading. Here, we present a new method to develop a silicon - carbon nanotube (CNT) hybrid anode architecture using CNT-polymer nanofiber hybridization method. The anode material is produced by electrospinning PMMA-Si nanofibers onto aligned CNT sheets, which are drawn on a grounded, rotating take-up roller, and then subsequently decomposing the PMMA electrospun fibers at elevated temperature to create a uniform distribution of Si particles within the CNT sheets. The whole structure is then coated with pyrolytic carbon via chemical vapor deposition (CVD). The architecture provides sufficient space to accommodate the volume expansion of the Si nanoparticles. The CVD pyrolytic carbon coating helps to anchor the Si nanoparticles within CNT sheets and stabilize solid-electrolyte-interface (SEI) formation. The novel freestanding, binder free CNT-Si-C sheet hybrid exhibited improved performance in terms of excellent cycling capacity (1470 mAh g−1), high coulombic efficiency (98%), and good capacity retention of 88% after 150 cycles.

Novel design of Fe3O4/hollow graphene spheres composite for high performance lithium-ion battery anodes

On account of its high theoretical capacity and low cost, Fe3O4 is regarded as a promising anode material for lithium-ion batteries. Nevertheless, many problems such as poor conductivity and volume expansion during lithiation severely limit its practical application. In this work, we synthesized hollow graphene spheres (HGSs) by self-assembly and innovatively combined it with Fe3O4 particles to obtain a composite material. The Fe3O4/HGSs composite exhibits excellent electrochemical performances as an anode material, which behaves an initial discharge specific capacity of 1670.8 mA h g−1 at 50 mA g−1 and 1048.5 mA h g−1 after 50 cycles. Especially, the specific capacity can maintain as high as 617.1 mA h g−1 at the current density of 1000 mA g−1, which is much higher than that of commercial graphite. While largely inhibiting agglomeration between the particles of Fe3O4 particles, hollow spheres composed of conductive and flexible graphene layers also provide an interconnected conductive network. We believe that this design in structure will also provide a new perspective for the researches of other transition metal oxides for lithium-ion batteries.

Co3O4 nanocrystalline-assembled mesoporous hollow polyhedron nanocage-in-nanocage as improved performance anode for lithium-ion batteries

Co3O4 nanocrystalline-assembled mesoporous hollow polyhedron nanocage-in-nanocage is synthesized through a metal-organic-framework-engaged strategy that relies on the unique chemical reactivity properties of zeolitic imidazolate framework-67. As anode material for lithium ion batteries, Co3O4 nanocage-in-nanocage shows high specific capacity (1271 mAh g−1 at 0.1C at the 2nd cycle) and good cycling stability (the capacity retention of 81.6% after 100 cycles), which can be attributed to beneficial effects of Co3O4 nanocrystalline and the mesoporous hollow nanocage-in-nanocage structure.

Double conductivity-improved porous Sn/Sn4P3@carbon nanocomposite as high performance anode in Lithium-ion batteries

Carbon encapsulated porous Sn/Sn4P3 (Sn/Sn4P3@C) composite is conveniently prepared by one-step electrochemical dealloying of Sn80P20 alloy in mild conditions followed by growing one carbon layer. Controllable dealloying of the Sn80P20 alloy results in the formation of bicontinuous spongy Sn4P3 nanostructure with a part of residued metallic Sn atoms embedded in the porous skeleton. A uniform carbon layer is deposited on the nanoporous Sn/Sn4P3 to prevent the nanostructure’s pulverizing and agglomerating during lithium ion insertion/extraction. Upon double conductivity modification from metallic Sn matrix and carbon layer, the as-made composite displays superior lithium-storage performances with much higher specific capacity as well as better cycling stability compared with pure porous Sn4P3. It offers a specific capacity of 837 mA h g−1 after 100 cycles at a rate of 100 mA g−1. Even after 700 cycles at the higher rate of 1000 mA g−1, the specific capacity still maintains as high as 589 mA h g−1. The Sn/Sn4P3@C material possesses promising application potential as an alternative anode in the lithium storage fields.

P doped onion-like carbon layers coated FeP nanoparticles for anode materials in lithium ion batteries

Except for low conductivity and huge volume expansion, FeP can be considered as a promising anode material for lithium ion batteries (LIBs). For overcoming these issues, P doped onion-like carbon layers coated FeP (FeP@(P, OLC)) nanoparticles have been one-pot prepared by arc discharging the Fe-P powers under the gas mixture of argon, hydrogen and ethanol, which have been designed for achieving excellent performance anode in LIBs. Being applied as anode material for LIBs, FeP@(P, OLC) core-shell structured nanoparticles deliver superior electrochemical performance by means of high initial coulombic efficiency (79.8%), stable cycle life (915 mA h g−1 at 0.1 A g−1 after 500 cycles) and excellent rate capability (averaged capacities of 379 and 237 mA h g−1 at 8.0 and 10.0 A g−1, respectively), which are ascribed to the synergistic effect of microstructure design and the composition optimization. P-doped OLC shells can alleviate the aggregation of FeP nanoparticles, offer the efficient channels for electrons and ions, and buffer the volumetric variety for FeP nanoparticles during the repetitive Li ion insertion/extraction process, avoiding partially the pulverization issue and improving cyclic stability. The facile synthesis strategy is expected to be helpful for designing and preparing transition metal phosphide nanoparticles coated by P doped OLC shell for energy storage applications.

Protective carbon-coated silicon nanoparticles with graphene buffer layers for high performance anodes in lithium-ion batteries

Silicon is a promising anode material for use in lithium-ion batteries (LIBs). However, its volume expansion problem can cause critical issues that deteriorate efficiency, cycle life, and result in sudden breakage of battery cells. Herein, polyethylene glycol derived thin carbon-coated Si nanoparticles (Si/c-PEG) and graphene wrapping were used to block electrolyte contact and buffer volume changes, respectively. The hierarchical graphene-wrapped Si/c-PEG (Si/c-PEG/G) exhibited outstanding performance with a gravimetric capacity of ∼1820 mAh/g at 0.1 A/g and 99.5% Coulombic efficiency at the 10th cycle. Moreover, the full-cell configuration using Si/c-PEG/G anodes with commercial lithium cobalt oxides (LiCoO2, LCO) cathodes demonstrated stable operation during repeated charge/discharge cycles at 0.1 and 1 C rates. Micelle coating of PEG with graphene layers was a useful method for minimizing the exposed area of silicon to the electrolyte during lithium-ion storage.

Lithiation behavior of graphene-silicon composite as high performance anode for lithium-ion battery: A first principles study

Graphene is superior as a contact with silicon active materials and their composite show very small volume expansion during charge processes. However, further study on atomistic-scale mechanism of the interaction between Li and Graphene-Silicon (Gra/Si) system is very challenging for current experimental technologies. In this work, the mechanism of Li adsorption on a Gra/Si system is investigated using density functional theory. Based on the calculated results of binding energies, charge transfer, charge density difference, mean squared displacement and diffusion constant, it concluded that the incorporation of graphene can significantly enhance the electrochemical performance of silicon as high performance anode material, which consists with the experimental results. A theoretical capacity of 2896 mAhg−1 is obtained, it is closed to the first cycle capacity of 2634 mAhg−1 in experiment. Moreover, the origin of irreversible capacity of Gra/Si system is investigated. The shorter bond lengths LiS and LiC are related to strong LiC and LiSi connections and irreversible capacity loss during lithiation. Then a reversible capacity of 2383 mAhg−1 is obtained by excluding the Li atoms with shorter bond lengths, and is comparable to the reversible capacity of 2497 mAhg−1 in experiment. The proposed computational frame can be used to evaluate and design nanocomposite anode materials for lithium-ion batteries.

Heterogeneous triple-shelled TiO2@NiCo2O4@Co3O4 nanocages as improved performance anodes for lithium-ion batteries

ZIF-67-derived NiCo2O4@Co3O4 double-shelled nanocages was coated by a layer of TiO2 shell, forming a heterogeneous triple-shelled cage-in-cage structure. As-synthesized triple-shelled nanocages were characterized by XRD, SEM and TEM. As anode materials for lithium ion batteries, triple-shelled nanocages show improved cycling stability and discharge capacity, which could be due to the cage-in-cage hollow nanostructure and beneficial effect of the TiO2 shell.

Pseudocapacitance behavior on Fe3O4-pillared SiOx microsphere wrapped by graphene as high performance anodes for lithium-ion batteries

A facile, scalable route is adopted to synthesize egg-like few-layered graphene-wrapped and Fe3O4-pillared SiOx anodes (SiOx@Fe3O4@FLG) for lithium-ion batteries. The rationally designed egg-like SiOx-cored composites possess a strong capability in accommodating volume change of micro-sized SiOx particles during Li cycling. Comprehensive effect of integrated structure, pseudocapacitance contribution and enhanced kinetics enables SiOx@Fe3O4@FLG electrode to afford a high-rate, long-term performance, e.g., 833.4 mA h g−1 (1550 mA h cm−3) at 0.5 A g−1 after 500 cycles with 81.8% capacity retention ratio. Such an attribute makes SiOx@Fe3O4@FLG composites promising anode materials for high-energy Li-ion battery.