High-performance Anode Materials For Lithium-ion Batteries Research Articles

The prospects of phosphorene as an anode material for high-performance lithium-ion batteries: a fundamental study

To completely understand lithium adsorption, diffusion, and capacity on the surface of phosphorene and, therefore, the prospects of phosphorene as an anode material for high-performance lithium-ion batteries (LIBs), we carried out density-functional-theory calculations and studied the lithium adsorption energy landscape, the lithium diffusion mobility, the lithium intercalation, and the lithium capacity of phosphorene. We also carried out, for the very first time, experimental measurement of the lithium capacity of phosphorene. Our calculations show that the lithium diffusion mobility along the zigzag direction in the valley of phosphorene was about 7 to 11 orders of magnitude faster than that along the other directions, indicating its ultrafast and anisotropic diffusivity. The lithium intercalation in phosphorene was studied by considering various Li n P16 configurations (n = 1–16) including single-side and double-side adsorptions. We found that phosphorene could accommodate up to a ratio of one Li per P atom (i.e. Li16P16). In particular, we found that, even at a high Li concentration (e.g. x = 1 in Li x P), there was no lithium clustering, and the structure of phosphorene (when fractured) is reversible during lithium intercalation. The theoretical value of the lithium capacity for a monolayer phosphorene is predicted to be above 433 mAh g−1, depending on whether Li atoms are adsorbed on the single side or the double side of phosphorene. Our experimental measurement of the lithium capacity for few-layer phosphorene networks shows a reversible stable value of ∼453 mAh g−1 even after 50 cycles. Our results clearly show that phosphorene, compared to graphene and other two-dimensional materials, has great promise as a novel anode material for high-performance LIBs.

Mesoporous TiO2@N-doped carbon composite nanospheres synthesized by the direct carbonization of surfactants after sol-gel process for superior lithium storage.

Here, we report mesoporous TiO2@N-doped carbon composite nanospheres synthesized via a double-surfactant-assisted assembly sol-gel process followed by sequential carbonization of surfactants under a N2 atmosphere. The resulting TiO2@N-doped C composite nanospheres are composed of uniformly distributed TiO2 nanocrystals with a diameter of ∼8 nm coated by a N-doped carbon layer that was formed by surfactants. Moreover, a large number of connected mesopores were observed in the nanospheres after high-temperature carbonization treatment. The synthesized nanospheres possess a large specific surface area (∼120 m2 g-1) and a large pore size (4-40 nm), with a well-defined spherical structure and a diameter in the nanoscale range. As an anode material for lithium-ion batteries (LIB), the mesoporous composite nanospheres delivered a reversible capacity of ∼117 mA h g-1 after 2000 cycles at a current rate as high as 10 C, as well as superior rate capability. The N-doped carbon layers greatly improved the overall electrical conductivity of the mesoporous TiO2 nanospheres. This study provides a remarkable synthetic route for the preparation of mesoporous TiO2-based N-doped carbon composite materials as high-performance anode materials in LIBs.

MOF derived ZnCo2O4 porous hollow spheres functionalized with Ag nanoparticles for a long-cycle and high-capacity lithium ion battery anode

Ag nanoparticle-decorated ZnCo2O4 hollow spheres are synthesized by using MOF templates and an Ag-mirror reaction, for high-performance lithium-ion battery anode materials.

Ultralong Sb2Se3 Nanowire-Based Free-Standing Membrane Anode for Lithium/Sodium Ion Batteries.

Metal chalcogenides have emerged as promising anode materials for lithium ion batteries (LIBs) and sodium ion batteries (SIBs). Herein, a free-standing membrane based on ultralong Sb2Se3 nanowires has been successfully fabricated via a facile hydrothermal synthesis combined with a subsequent vacuum filtration treatment. The as-achieved free-standing membrane constructed by pure Sb2Se3 nanowires exhibits good flexibility and integrity. Meanwhile, we investigate the lithium and sodium storage behavior of the Sb2Se3 nanowire-based free-standing membrane. When applied as the anode for LIBs, it delivers a reversible capacity of 614 mA h g-1 at 100 mA g-1, maintaining 584 mA h g-1 after 50 cycles. When applied as the anode for SIBs, it delivers a reversible capacity of 360 mA h g-1 at 100 mA g-1, retaining 289 mA h g-1 after 50 cycles. Such difference in electrochemical performance can be attributed to the more complex sodiation process relative to the corresponding lithiation process. This work may provide insight on developing Sb2Se3-based anode materials for high-performance LIBs or SIBs.

MoO2 nanoparticles grown on carbon fibers as anode materials for lithium-ion batteries

Molybdenum dioxide (MoO2) nanoparticles were synthesized on carbon fibers by a facile hydrothermal method. The XRD results reveal that the obtained nanoparticles have a monoclinic phase with diameter in the range of tens of nanometers, which could be directly functionalized for application in the lithium-ion batteries (LIBs). The annealed MoO2 nanoparticles exhibit high specific capacity and excellent cycling stability. A high discharge capacity of 1117mAhg−1 can maintain after 50 cycles at the rate of 0.5C. In view of the excellent lithium storage properties and the ease in large-scale preparation, the as-synthesized MoO2 nanoparticles might be used as promising anode materials for high-performance LIBs.

Porous CoC2O4 Nanorods as High Performance Anode Material for Lithium Ion Batteries

A porous structure has great advantages in electrodes for lithium ion batteries (LIBs), because it can not only offer a large surface area for the electrode to contact the electrolyte, but can also relieve the mechanical stress derived from Li+ insertion/extraction. In this work, porous CoC2O4 nanorods were synthesized through a facile metathesis reaction using H2C2O4·2H2O and Co(CH3COO)2·4H2O as raw materials. The porous CoC2O4 nanorods show excellent electrochemical properties including high specific capacity, long cycling stability and good rate capability. After 100 cycles, the electrode maintained a capacity of 1230 mAh g−1 at a current density of 500 mA g−1. Even at a high current density of 4000 mA g−1, the sample still delivered a capacity of 385 mAh g−1. These results indicate that porous CoC2O4 nanorods are an exceptional anode material for high-performance LIBs.

3D Hierarchical Anode Configuration Composed of Ultralong N-Doped Graphene Scrolls-Wrapped MnO Nanowires for High-Performance Li-Ion Batteries

Transition metal oxides (TMOs) have been touted as one of the most promising anode materials for next generation lithium ion batteries (LIBs). Yet, how to build energetic TMOs-based electrode architectures by addressing the structural and interfacial stability issues facing TMOs anodes still remains a big challenge. Here, we design and fabricate a novel 3D hierarchical anode configuration composed of ultralong porous MnO nanowires (NWs) wrapped within nitrogen-doped graphene scrolls (GSC) which themselves interlinked and embedded in continuous interconnected networks of nitrogen-doped graphene ribbons (GR). Such a hybrid material (namely, MnO@N-GSC/GR) with plenty of internal void space is totally in an ordered 3D hierarchical porous architecture by taking the advantage of multi-scale and multi-dimensional integration of nanoscaled MnO and graphene building blocks, which can address all the issues related to MnO dissolution, conversion, aggregation and volumetric expansion during the Li+ insertion/extraction. As a result, the 3D hierarchical MnO@N-GSC/GR serves high-performance anode materials for LIBs with a very high reversible specific capacity (as high as 765 mAh g-1 at even 1000 mA g-1) and ultrafast rate capability (349 and 201 mAh g-1 at 8000 and 15000 mA g-1, respectively), as well as excellent discharge and charge capabilities (rapidly charged to 86.7% and 79.9% in 10.5 and 4.6 min, respectively, using the constant current mode). Most importantly, such the robust MnO@N-GSC/GR electrode shows no capacity fading even after 1000 cycles at a high current density of 2000 mA g-1, and no morphology change. The as-built 3D hierarchical MnO@N-GSC/GR is the most efficient MnO-based anode materials ever reported for LIBs.

Lithiation Kinetics in High-Performance Porous Vanadium Nitride Nanosheet Anode

Vanadium nitride (VN) is promising in lithium ion battery (LIB) anode due to its high energy density, chemical stability, and corrosion resistivity. Herein, porous VN nanosheets are synthesized hydrothermally followed by an ammonia treatment. The porous nanosheets offer a large interfacial area between the electrode and electrolyte as well as short Li+ diffusion path and consequently, the VN nanosheets electrode has high capacity and rate capability as an anode in LIB. The VN anode delivers a high reversible capacity of 455mAhg−1 at a current density of 100mAg−1 and it remains at 341mAhg−1 when the current density is increased to 1Ag−1. The charge transfer and Li+ diffusion kinetics during the lithiation process is studied systematically. A highly stable SEI film is formed during the initial discharging-charging cycles to achieve a long cycle life and sustained capacity at a high level for 250 discharging-charging cycles without deterioration. This work demonstrates the preparation of high-performance LIB anode materials by a simple method and elucidates the lithiation kinetics.

Controllable Fabrication of CoMn2O4 Microflowers and Microspheres As High-Performance Lithium Ion Battery Anode Material

The growing electric vehicle requirements have attracted great interest in development of lithium ion batteries (LIBs) with large gravimetric and volumetric capacities, long cycle lifespan. To meet these applications, high quality electrode materials are needed. However, conventional bulk electrode materials cannot fully reach the increasing demands due to their inherent limits in performance. In recent years, nanostructured electrode materials with higher rate capability have been acknowledged by low lithium-ion diffusion distance and high electrode/electrolyte area. However, electrode made from nanostructured electrode materials meets these challenges. (1) Nanoparticles tend to self-aggregate and the side reaction with the electrolyte due to high specific surface area, which lead to low initial coulombic efficiency and poor cycling life. (2) Nanoparticles have a huge volume changes during Li+ insertion/ extraction that result in fracture of nanostructured particle, delaminating of the conductive coating and low capacity with cycle increasing. (3) Nanostructured particles have low tap density which results in a low volumetric energy density.Therefore, the electrode materials with optimal structure should be developed to deal with above-mentioned problems. Micro-/nanostructures with controlled size and morphology have attracted considerable attention as high-performance anode materials for next-generation LIBs. This micro-/nanostructure should be a porous microstructure composed of primary nanocrystallines tightly compacted to form 3D channels for ion diffusion. Moreover, this structure can exploit many advantages of nanostructure for lithium ion batteries due to the reduction of side reactions with electrolyte, leading to high density and long cycling life with high safety. Some simple micro-/nano-structured metal oxides such as Mn-based oxides, Co-based oxides, Fe-based oxides and Sn-based oxides, have been recently reported for use in LIBs. Mn-based oxide electrodes (MnO, MnO2, Mn2O3, Mn3O4, ZnMn2O4, NiMn2O4 and CoMn2O4) are developed due to low operating voltages (1.3-1.5 V for lithium extraction) and high energy density. Among these Mn-based anodes, CoMn2O4 has been considered for substitution of the conventional graphite anode in LIBs. The shape and micro/nanostructure of CoMn2O4 material play an important role in the electrochemical performances. In this paper, uniform hierarchical porous CoMn2O4 microspheres and microflowers were realized by adjusting the urea concentration through a solvothermal process followed by a post-annealing treatment. In the low urea concentration, the microflower with diameter size of around 10 μm is composed of porous nanosheets with a thickness of about 20 nm. In the high urea concentration, a large amount of uniform CoMn2O4 microspheres is obtained with average diameter of about 8 μm. CoMn2O4 microsphere is highly porous and composed of numerous primary nanoparticles. As expected, the distribution of the O, Mn and Co elements is homogeneously distributed on the surface for CoMn2O4 microflower and microsphere. The actual molar ratios of Mn and Co for CoMn2O4 microflower and microspheres obtained from energy-dispersive X-ray (EDX) analysis are close to 2, which are consistent with the ratio of that in the precursor solution. The chemical compositional and crystalline structural changes of as-prepared samples were characterized using X-ray diffraction (XRD) and thermogravimetric analysis (TGA). These results show the precursor in the low urea concentration is a MnCo-complex structure (including CoMn-layered double hydroxide and CoMn-glycolates or alkoxide derivatives) in an alkaline environment under this solvothermal conditions. Meanwhile, in the high urea concentration, the precursor Co1/3Mn2/3CO3 sample is formed. The possible formation mechanism of as-prepared CoMn2O4 microsphere and microflower precursors is explained due to the presence of CO2 pressure into the reaction solution. When used as anode materials for lithium-ion batteries, the porous CoMn2O4 microflower and microspheres exhibited good long-life cycling performance at high rate density. At a current density of 100 mA g-1, the CoMn2O4 microflower and microspheres exhibit an initial capacity of 1200 and 1225 mA h g-1 and the capacity is maintained at 710 and 220 mAh g-1 after 50 cycles. Excellent rate capabilities (~813 mAh g-1 at 200 mA g-1 and ~612 mAh g-1 at 600 mA g-1) are observed for CoMn2O4 microspheres. Based on these results, the good electrochemical properties can result from the porous CoMn2O4 microspheres. On the one hand, the micro-/nano porous structured CoMn2O4 microspheres could significantly enhance the electrode integrity by buffering the volume changes with repeating Li+ insertion/ extraction, which is contributed to good cycling stability. On the other hand, the micro-/nano porous structured CoMn2O4 microspheres provide extra active position for Li+ storage and short Li+ ion diffusion length, contributing to the high specific capacity and better rate capability. The CoMn2O4 hierarchical porous microspheres, which have good electrochemical performance and ease of fabrication, hold the great promise as the anode materials for high-performance LIBs. Figure 1

Structural Design and Electrochemical Performances of Hollow Metal Oxide/Carbon Core-Shell Fibers

Transition metal oxide (MOx) offers great potential as anode for lithium ion batteries (LIBs) due to the high theoretical capacity compared with that of commercial graphite. However, several limitations, such as large volume variation during repeated cycling, slow kinetics and low electrical conductivity, have severely limited the practical performance in application. Here, we report a rational design of hollow metal oxide/carbon core-shell fibers (MOx/C, M= Sn, Ge) and the synthesis of the material via facile co-axial electrospinning process (Figure 1a). The unique hollow core-shell structure of MOx/C with MOx nanoparticles encapsulated into hollow carbon shells can provide a buffer layer to suppress the fracture of MOx nanoparticles caused by repeated volume changes, good conductivity and short diffusion paths for Li ions as well as stable solid electrolyte interphase (SEI) layer. Meanwhile, sufficient space between MOx nanoparticles and the carbon shell is contributed to accommodate the volume expansion of MOx during cycling process (Figure 1b–1c). As the anodes for LIBs, the as-prepared SnO2/C and GeOx/C electrodes exhibit excellent lithium storage performance, showing high reversible specific capacity of 833 mAh g−1 after 500 cycles at 600 mA g−1 and 875 mA h g−1 after 400 cycles at 160 mA g−1, respectively. The structural design in this paper can provide a novel strategy for the research of high-performance anode materials for LIBs.

2D sandwich-like carbon-coated ultrathin TiO2@defect-rich MoS2 hybrid nanosheets: Synergistic-effect-promoted electrochemical performance for lithium ion batteries

Poor cycling performance and rate capability are the major barriers to the application of layered transition-metal sulfide as the next generation anodes materials for lithium-ion batteries (LIBs). In this paper, a smart composite consisting of defect-rich MoS2/carbon-coated ultrathin TiO2/defect-rich MoS2 sandwich-like nanosheets has been constructed to enhance the cycling and rate performances of MoS2. In this uniform sandwich-like structure, carbon-coated ultrathin TiO2 is conformably embedded by defect-rich MoS2 shells via intimate interfacial contacts, while the carbon coats TiO2via Ti–O–C bonds. It is first revealed that the synergistic effect between rich defect in few-layer MoS2 nanosheets and abundant interfaces in the composites, as well as the high structure stability of TiO2 during discharge and charge process, results in excellent performance of the composites as LIBs anode materials. These LIBs anodes achieve the best rate capability (785.9, 507.6 and 792.3mAhg−1 at 0.1, 2 and 0.1Ag−1, respectively) and cycling performance (805.3mAhg−1 at 0.1Ag−1 after 100 cycles) among the TiO2 supported MoS2 based composites reported previous. The synergistic strategy can be expected to benefit the rational design of other anode materials for high-performance LIBs.

Large-scale synthesis of NiO polyhedron nanocrystals as high-performance anode materials for lithium ion batteries

NiO polyhedron nanocrystals have been synthesized using a single source of nickel chloride through a calcination reaction. The electrochemical results displayed that the obtained sample is an outstanding anode material for lithium ion batteries (LIBs). The sample maintains a high specific capacity of 645.5mAhg−1 at current density of 1000mAg−1 after 100 cycles. Even at high current density of 4000mAg−1, the NiO polyhedron nanocrystals still deliver a capacity of 459.6mAhg−1. The high specific capacity, long stable cyclic property and good rate capability make the NiO polyhedron nanocrystals a good candidate anode material for high-performance LIBs.

Rational combination of α-MnS/rGO nanocomposites for high-performance lithium-ion batteries

An α-MnS/rGO nanocomposite has been synthesized by forming homogeneous cubic α-MnS nanoparticles on reduced graphene oxide by a facile hydrothermal method. The obtained α-MnS/rGO nanocomposite has been employed as an anode material for lithium-ion batteries (LIBs) and shown greatly enhanced performance with a higher specific capacity and better cycling stability than the pure α-MnS nanoparticles. At a current density of 0.2 A g−1, the initial discharge (lithiation) and charge (delithiation) capacities of the α-MnS/rGO nanocomposite are 1215 mA h g−1 and 716 mA h g−1, respectively, and the discharge capacity still remains at 670 mA h g−1 even after 100 cycles. Compared with the pure α-MnS nanoparticles, the α-MnS/rGO nanocomposite has high conductivity, large surface area and mitigative structural strain, which could be beneficial for improving the electrochemical performance. These results along with its high specific capacity and good cycling and rate capability suggest that the α-MnS/rGO nanocomposite would be a promising candidate as an anode material for high-performance LIBs.

Scalable preparation of silicon@graphite/carbon microspheres as high-performance lithium-ion battery anode materials

Silicon materials have received extensive research interest due to their high specific capacity of 3579 mA h g−1and appropriate potential of approximately 0.4 Vvs.Li/Li+.

Fabrication of novel rugby-like ZnSnO3/reduced graphene oxide composites as a high-performance anode material for lithium-ion batteries

Fine ZnSnO3/reduced graphene oxide nanocomposites (ZSGNC) were successfully synthesized via a simple colloid flocculation method. Morphology analysis showed that the rugby-like ZnSnO3 nanoparticles (NPs) (~4nm in size) were well distributed on the reduced graphene oxide (rGO) sheets. The as-prepared ZSGNC manifested high specific capacity and improved cycling stability for a potential anode material in lithium-ion batteries (LIBs), which delivered an initial discharge capacity of 1691mAhg−1 at 100mAg−1 and retained 713mAhg−1 after 100 cycles. These results indicate that the ZSGNC is a promising anode material for high-performance LIBs.

Facile synthesis of one-dimensional zinc vanadate nanofibers for high lithium storage anode material

One-dimensional (1D) zinc vanadate (α-Zn2V2O7) nanofibers have been synthesized through electrospinning combined with an annealing process. When used as anode material for lithium-ion batteries (LIBs), electrospun 1D α-Zn2V2O7 nanofibers exhibit a reversible capacity of ∼708 mAh g−1 after 100 cycles at a current density of 50 mA g−1. A good rate capability is also achieved even at higher current densities. When cycled at a current density of 2000 mA g−1, the electrode can still show a reversible capacity of ∼311 mAh g−1. The excellent cycle performance and rate capability may be due to the 1D nanofiber architectures, mesoporous structures, and relatively large specific surface area, which can provide a short ion diffusion path and continuous electron transportation. Therefore, this work presents a simple and efficient approach for fabrication of 1D α-Zn2V2O7 nanofibers, which are promising high-performance anode materials for LIBs.

Interconnected porous NiO@MnO2 nanosheets as anodes with excellent rate capability for lithium-ion batteries

Interconnected porous NiO@MnO2 nanosheets are synthesized on nickel foam by hydrothermal method. As an anode of lithium-ion batteries (LIBs), such a architecture could shorten the diffusion distance of lithium ions and largen the contact area between the active material and electrolyte. It displays a high capacity of 1000mAhg−1 after 160cycles at a rate of 1.0C. More importantly, the electrode exhibits an excellent rate performance, it delivers a capacity about 787mAhg−1 at 5.0C. The superior lithium storage properties suggest that the interconnected porous NiO@MnO2 nanosheets can function as a promising anode material for high-performance LIBs.

MoS2/Graphene Hybrid Nanoflowers with Enhanced Electrochemical Performances as Anode for Lithium-Ion Batteries

In this work, we studied the synthesis and electrochemical performance of MoS2 and reduced graphene oxide (rGO) hybrid nanoflowers for use as anode material in lithium ion batteries (LIBs). The morphology and microstructure of the samples were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectrometry (XPS). Herein, the composite nanoflowers delivered a significant enhanced reversible specific capacity and charge/discharge cycle stabilities as anode in comparison with pristine MoS2. Electrochemical impedance spectroscopy (EIS) measurements indicated that the incorporation of rGO significantly reduced the contact resistance and the improved electrochemical performances could be attributed to the synergy effect between the functions of MoS2 and rGO. A high reversible capacity of 1150 mAh/g at a current of 0.1 A/g could be retained without fading after 60 cycles. The rate performance of the composite was also improved, and the specific capacity remained at the relative high value of ∼890 mAh/g even at a current of 1 A/g. In order to further systematically study the mechanism of the improved LIBs performances for composite, we constructed the corresponding models based on experiment data and conducted a first-principles calculation. The nudged elastic band (NEB) method was employed to study the diffusion of Li in different structures. The calculated results proved that the diffusion barrier for Li in MoS2/graphene was significantly lower than that in pristine MoS2 and presented a theoretical explanation for a better diffusivity property. The high specific capacity and excellent cycling stability of these hybrid nanoflowers are competent as a promising anode material for high-performance LIBs.

Recycled diesel carbon nanoparticles for nanostructured battery anodes

Considerable attention has been devoted to using rational nanostructure design to address critical carbonaceous anode material issues for next-generation lithium-ion batteries (LIBs). However, the fabrication of nanostructured carbonaceous anode materials often involves complex processes and expensive starting materials. Diesel engine is an important source of nanostructured carbon particles with diameters ranging 20 nm–60 nm suspended in air, resulting in a serious scourge of global climate and a series of diseases such as lung cancer, asthma, and cardiovascular disease. Here, we show that diesel carbon nanoparticles collected from diesel engines can be chemically activated to create a porous structure. The resulting nanostructured carbon electrodes have a high specific capacity of 936 mAh g−1 after 40 cycles at 0.05 A/g, and excellent cycle stability while retaining a capacity of ∼210 mAh g−1 after 1200 cycles at 5 A/g. As recycled diesel carbon nanoparticles are readily available due to the several billion tons of diesel fuel consumed every year by diesel engines, their use represents an exciting source for nanostructured carbonaceous anode materials for high-performance LIBs and improves our environment and health.

Three-dimensional hierarchical Co3O4/CuO nanowire heterostructure arrays on nickel foam for high-performance lithium ion batteries

Novel three-dimensional (3D) hierarchical Co3O4/CuO nanowire (NW) arrays on nickel foam composed of CuO NW stems and Co3O4 nanosheet branches are synthesized by combining a facile, scalable, and cost-effective thermal oxidation method with a simple but powerful chemical bath deposition followed by a calcination process. These arrays are further investigated as binder- and conductive-agent-free anodes for lithium-ion batteries (LIBs). The smart hybridization of CuO NWs and Co3O4 nanosheets into hierarchical core/shell array configuration results in remarkably enhanced electrochemical performances with good cycle performance, high reversible capacity, and excellent rate capability compared with pure CuO NW and single net-like Co3O4 nanosheets. A high reversible capacity of 1191mAhg−1 with 90.9% capacity retention after 200 cycles at a current density of 200mAg−1, and reversible capacity up to 810mAhg−1 even after 500 cycles at a current density as high as 1000mAg−1 can be maintained. The superior electrochemical performances of electrodes composed of hierarchical Co3O4/CuO NW arrays connected directly on nickel foam make them potential anode materials for high-performance LIBs.