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In this paper, orthorhombic phase zirconium monosilicide nanomaterials have been successfully synthesized through a lithium thermal reduction in a stainless-steel autoclave at a low temperature of 600 0C. X-ray diffraction indicates that the obtained product is orthorhombic zirconium monosilicide. Scanning electron microscopy shows that the obtained zirconium monosilicide product consists of nanoparticles and nanorods. The oxidation resistance of the obtained zirconium monosilicide product is investigated.

Hafnium diboride (HfB2) nanoparticles have been prepared by a solid-state reaction of hafnium dioxide (HfO2), metallic magnesium (Mg) and sodium borohydride (NaBH4) at 700°C in an autoclave. The structure and morphology of the obtained product are investigated by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The transmission electron microscopy (TEM) image shows that the average size of HfB2 nanoparticles is about 30 nm. The oxidation behavior of HfB2 is studied by thermogravimetric analysis (TGA). It has good thermal stability and oxidation resistance below 380°C in air. Furthermore, the possible formation mechanism of HfB2 is also discussed.

In this paper, Ni2P nanoparticles is incorporated onto the graphene & carbon nanotubes composite (Ni2P NPs/rGO & CNTs) to form flexible free-standing intertwining network film anodes for improving the cycle-life of sodium-ion batteries (SIBs). Benefited from the volume accommodation by this Ni2P NPs/rGO & CNTs structure and its excellent electronic conductive network along with high mechanical strength, such an anode-based SIB shows a superior capacity retention with a stable and long cycle-life at high current densities. For Ni2P NPs/rGO & CNTs electrode, it remains a capacity of 224 mAh g−1 after 100 cycles, at a high current density of 0.5 A g−1, the Ni2P NPs/rGO & CNTs can still maintain a stable reversible capacity of ~ 150 mAh g−1 after 500 cycles, after cycling at a rate as high as 1 A g−1, the reversible capacity of the Ni2P NPs/rGO/CNT can still sustain stable capacities at 91 mAh g−1 after 2000 cycles, respectively. Even at 5 A g−1, it still exhibits a high rate capacity of 65 mAh g−1, thus exhibiting an excellent sodium storage kinetics.

Herein, we have synthesized niobium carbide/carbon (NbC/C) nanocomposites by a magnesium-thermal reduction process at 600 °C in a stainless-steel autoclave. X-ray diffraction patterns indicate that...

Sodium ion batteries (SIB) have wide applications in the field of energy storage due to their low cost. Currently, due to its higher theoretical discharge capacity, tin and tin-based compounds are expected to become SIB anode materials. Here, 2D SnS2 nanosheets with thickness of about 20 nm loaded on reduced graphene oxide (RGO) material (SnS2/RGO) was synthesized by a hydrothermal method, which display superior properties. When the denseness of current is 100 m A/g, the discharge capacity of the first cycle is as high as 956.1 m Ah/g, and the initial Coulombic efficiency is up to 60.0%. From the third cycle to the 200th cycles, the capacity decline rate of each cycle is about 0.13%; after 200 cycles the discharge capacity is still 443.4 m Ah/g. This outstanding performance is ascribed to the composite structure of SnS2/RGO, which helps to alleviate the stress of volume change during sodium ion insertion and extraction and enhances the conductivity of the SnS2 material.

Recycling of waste tires is an important technology due to the health and environmental problems caused by them. Herein, we developed a low-cost method to prepare phosphorus-doped mesoporous carbon (PMC) by a preferred phosphoric acid treatment and high temperature calcination process of waste tires. After doping with phosphorus, the PMC electrode exhibited improved reversible capacity (181.8 mA h/g @ 100 mA/g) and good rate performance. It still delivers a specific capacity of 128.5 mA h/g when cycled under 500 mA/g. The increased performance of PMC was owing to the joint effect of phosphorus doping and mesoporous structure, which could shorten the transport path of K+ and improve the electrochemical reactivity for potassium batteries.

Uniform nanospherical Li 2 MnSiO 4 /C/graphene composites have been obtained by polyethylene glycol-600 (PEG-600) assisted solid-state reaction using spherical SiO 2 as precursor, and heat treatment with the mixed carbon sources (glucose, cellulose acetate and graphene oxide). The transmission electron microscope (TEM) images show that Li 2 MnSiO 4 nanospheres with size of 50 nm are embedded in the three-dimensional (3D) nest-like carbon network. Electrochemical measurements reveal that the composites exhibit first discharge capacity of 215.3 mAh g −1 under 0.05 C, together with a stable discharge capacity of 175 mAh g −1 after 40 cycles. The 3D carbon network and the carbon layer (amorphous carbon and graphene) are favorable for improving the electrochemical performance.

The rod‐like and bundle‐like γ‐LiV2O5 were synthesized via a simple solvothermal processing. The rod‐like γ‐LiV2O5 with diameter of 500–800 nm and the bundle‐like architectures are composed of several of order‐attached rods with diameter of 100–600 nm. γ‐LiV2O5 were synthesized using LiOH·H2O, NH4VO3, HNO3, C2H5OH without and with PVP as raw materials. At the same time, the actual formation mechanism of γ‐LiV2O5 was also investigated. As the cathode materials for lithium ion batteries, the bundle‐like γ‐LiV2O5 prepared with PVP delivers a better electrochemical performance, which has an initial discharge capacity of 269.3 mAh/g at a current density of 30 mA/g and is still able to achieve 228 mAh/g after the 20th cycle. The good electrochemical properties of the as‐synthesized γ‐LiV2O5 coupled with the simple, relatively low temperature, and low cost of the preparation method may make this material a promising candidate as a cathode material for lithium ion batteries.

Fe 3 O 4 /C composites have been prepared by sucrose calcining with Fe 3 O 4 particles obtained from ferrous oxalate decomposition. The scanning electron microscopy (SEM) images show that Fe 3 O 4 nanoparticles (Fe 3 O 4 NPS) with average size of 200 nm are embedded in the three-dimensional (3D) carbon-framework. As an anode material for rechargeable lithium-ion batteries, the Fe 3 O 4 /C composite delivers a reversible capacity of 773 mAh g −1 at a current density of 924 mA g −1 after 200 cycles, higher than that of the bare Fe 3 O 4 NPS which only retain a capacity of 350 mAh g −1 . When the current density rises to 1848 mA g −1 , Fe 3 O 4 /C material still remains 670 mAh g −1 even after 400 cycles. The enhanced high-rate performance can be attributed to the 3D carbon-framework, which improves the electric conductivity, relaxes the strain stress and prevents the aggregation of Fe 3 O 4 particles during the charge/discharge process.

LiFePO 4 nanopolyhedrons with the size of ~ 200 nm have been solvothermally synthesized in the binary solvent of benzyl alcohol and ethylene glycol. As citric acid added, microellipsoids with an average size of 1 μm were formed. LiFePO 4 nanopolyhedrons and microellipsoids were coated by carbon layers using cellulose acetate as carbon source. Electrochemical measurements showed that the LiFePO 4 /C nanopolyhedrons could deliver a discharge capacity of 145 mAh g − 1 under 1 C and had a capacity decay rate of 4 /C microellipsoids had a discharge capacity of 123 mAh g − 1 under 1 C and the capacity decay rate was less than 8% after 200 cycles.

LiMnPO4 nanosquares with the edge size of 800–1000 nm and the thickness of 50–250 nm were hydrothermally prepared using 1.0 g of Na4P2O7·10H2O. Subsequently, the LiMnPO4 nanosquares were annealed w...

Various CuO nanostructures have been well studied as anode materials for lithium ion batteries (LIBs); however, there are few reports on the synthesis of porous CuO nanostructures used for anode materials, especially one-dimensional (1D) porous CuO. In this work, novel 1D highly porous CuO nanorods with tunable porous size were synthesized in large-quantities by a new, friendly, but very simple approach. We found that the pore size could be controlled by adjusting the sintering temperature in the calcination process. With the rising of calcination temperature, the pore size of CuO has been tuned in the range of ∼0.4 nm to 22 nm. The porous CuO materials have been applied as anode materials in LIBs and the effects of porous size on the electrochemical properties were observed. The highly porous CuO nanorods with porous size in the range of ∼6 nm to 22 nm yielded excellent high specific capacity, good cycling stability, and high rate performance, superior to that of most reported CuO nanocomposites. The CuO material delivers a high reversible capacity of 654 mA h g(-1) and 93% capacity retention over 200 cycles at a rate of 0.5 C. It also exhibits excellent high rate capacity of 410 mA h g(-1) even at 6 C. These results suggest that the facile synthetic method of producing a tunable highly porous CuO nanostructure can realize a long cycle life with high reversible capacity, which is suitable for next-generation high-performance LIBs.

Orthorhombic LiMnO 2 porous microspheres with the pore size of 200-500 nm were synthesised by Mn 2 O 3 precursor and LiOH·H 2 O at 750°C for 5 h. Field-emitting scanning electron microscope images show the obtained products basically preserve the initial morphology of Mn 2 O 3 precursor. The electrochemical tests of the as-obtained LiMnO 2 presented the maximum discharge capacity of 163 mAh/g at the 11th cycle, and remained above 143 mAh/g after 30 cycles at a current density of 30 mA/g, corresponding to a capacity fading of 12.1%. For comparative purpose, the LiMnO 2 nanoparticles prepared with the Li 2 CO 3 substituted for LiOH·H 2 O as the lithium source were studied, which showed their maximum discharge capacity was only 153 mAh/g, together with a capacity of 136 mAh/g after 30 cycles at the same current density.

In this work, nanocrystalline-assembled bundle-like CuO structures were successfully synthesized in large-quantity by a friendly, facile two-step process. The bundle-like CuO particles are produced by thermolysis of bundle-like Cu(OH)2 precursors, which exhibit excellent high specific capacity, high stability, and especially high rate performance for anode materials in lithium-ion batteries, superior to that of most reported CuO-based anodes. The assembled structure of CuO endows it with high rate capacities of 666 mAh g−1, 609 mAh g−1, and 499 mAh g−1 at a current rate of 0.3 C, 1 C and 2 C after 50 cycles, respectively. Even at a high rate of 6 C, the bundle-like CuO can still deliver a capacity of 361 mAh g−1. It is observed that the electrochemical performance of the nanocrystalline-assembled bundle-like CuO is much better than that of CuO nanoparticles obtained by destroying the assembled bundle-like CuO through grinding. XRD analysis of both the electrodes after ending the discharge/charge proved that during the discharge/charge process, the conversion reactions occurring in the assembled structures have better reversibility, leading to the high rate capacity and cycling performances. The better reversibility originates from the better contact area for CuO/electrolyte, enhancing many sites to the access of Li+ in the electrolyte Li+. In addition, the assembled bundle-like CuO architectures can also relieve the volume variations during the Li+ uptake–release process, which also contributes to the excellent electrochemical performance. The high rate capacity and enhanced cycling stability of the bundle-like CuO structure make it a promising candidate as an anode material for high-performance Li-ion batteries.