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FeS2/CoS and FeS2/CoS/C composites were synthesized by solvothermal method and following vapor phase vulcanization at mild temperature with binary oxide CoFe2O4 as precursors. All FeS2/CoS composites prepared at different molar ratios of Fe3+ and Co2+ ions exhibit the similar morphology of solid microspheres. As anode materials for lithium-ion batteries (LIBs), the as-prepared FeS2/CoS and FeS2/CoS/C composites show higher reversible capacity and better cycling performance, compared with the bare FeS2 and CoS. Among them, the FeS2/CoS composite with molar ratio of Fe3+ and Co2+ of 2:1 exhibits the high reversible capacity of 1150 mAh g−1 after 100 cycles at 100 mA g−1 and even 610 mAh g−1 at 1.0 A g−1 after 900 cycles. This strategy for synthesizing the heterogeneous structure of binary sulfide can effectively improve the kinetic which thus enhance the electrochemical performance of materials. This work can provide an effective method and idea for the preparation and modification of FeS2 and other transition metal sulfide anode materials for LIBs in the future. [ABSTRACT FROM AUTHOR]

Different amounts of Fe2O3-coated NiMoO4/NiO composites were prepared by solvothermal method following with annealing process. The as-prepared NiMoO4/NiO@Fe2O3 composite exhibits a reversible specific capacity of 1250 mAh g−1 after 150 cycles at a current density of 100 mA g−1 as anode for lithium-ion batteries. It exhibits efficient long-term electrochemical performance and maintains the capacity at about 750 mAh g−1 at a high current density of 500 mA g−1 after 200 cycles. The good electrochemical performance of the NiMoO4/NiO@Fe2O3 composite may be due to its smaller size and the Fe2O3 coating which can restrain its volume collapse during the charge–discharge cycle. This work could provide a promising strategy for enhancing the performance of molybdate-based composite materials for practical application in lithium-ion batteries. [ABSTRACT FROM AUTHOR]

NiCo2S4 and NiCo2S4/carbon nanotube (CNT) nanocomposites were synthesized via a one-step hydrothermal approach. As anode materials for lithium-ion batteries (LIBs), the NiCo2S4/CNT nanocomposite delivers significantly improved cycling stability and excellent rate performance, compared with the pure NiCo2S4. It retains a discharge capacity of 1405.7 mAh g−1 after 80 cycles at 200 mA g−1 with only 9.2% capacity degradation. Moreover, a discharge capacity of 711.6 mAh g−1 after 390 cycles can still be maintained even at a high current density of 1 A g−1. The results demonstrate that the NiCo2S4/CNT nanocomposite holds great potential for applications in LIBs. [ABSTRACT FROM AUTHOR]

The composites of Li3V2(PO4)3/C (noted as LVP/C) and Li3V2(PO4)3-V2O3/C (noted as LVP-V/C) are prepared by a rheological phase reaction (noted as RPR) process for anode material. The synthesized samples are measured by the X-ray diffraction (XRD) technique. The content of the carbon in the composite is detected by the thermogravimetric (TG) analysis. The morphologies of powders are observed by the scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical properties of the samples as anode material are tested by the battery testing system. The LVP-V/C composite behaved better electrochemical performances than those of LVP/C as an anode material. The reasons that LVP-V/C behaved outstanding electrochemical properties are discussed also. Based on its electrochemical performances, the LVP-V/C composite may be a potential anode material for rechargeable lithium batteries. [ABSTRACT FROM AUTHOR]

High capacity electrode materials are the key for high energy density Li-ion batteries (LIB) to meet the requirement of the increased driving range of electric vehicles. Here we report the synthesis of a novel anode material, Bi2MoO6/palm-carbon composite, via a simple hydrothermal method. The composite shows higher reversible capacity and better cycling performance, compared to pure Bi2MoO6. In 0–3 V, a potential window of 100 mA/g current density, the LIB cells based on Bi2MoO6/palm-carbon composite show retention reversible capacity of 664 mAh·g−1 after 200 cycles. Electrochemical testing and ab initio density functional theory calculations are used to study the fundamental mechanism of Li ion incorporation into the materials. These studies confirm that Li ions incorporate into Bi2MoO6 via insertion to the interstitial sites in the MoO6-layer, and the presence of palm-carbon improves the electronic conductivity, and thus enhanced the performance of the composite materials. [ABSTRACT FROM AUTHOR]

Transition-metal oxalates (TMOs) have demonstrated great potentials as the promising anode material for lithium ion batteries. Herein, a hierarchical structure was designed and constructed using manganese oxalate framework with accurate iron doping strategy. Owing to the synergistic effect from mixed metal oxalates and staggered conductive network from porous sheet morphology, the Mn 0.8 Fe 0.2 C 2 O 4 with optimal Fe doping presents ultra-efficient lithium storage ability. For example, The as-prepared Mn 0.8 Fe 0.2 C 2 O 4 electrode delivers an initial discharge capacity of 2275 mAh∙g−1, and the reversible capacity around 1903/2018 mAh∙g−1 after 100/200 cycles at 100 mA∙g−1, respectively. Besides, it also demonstrates excellent rate performance, and a high discharge capacity of 1045 mAh∙g−1 after 500 cycles at 500 mA∙g−1. The improved electrochemical performance is superior to previously reported for metal oxalates. Therefore these strategies about the hierarchical synthesis of different morphologies of Mn x Fe 1-x C 2 O 4 can display a huge application prospect in the industrialization of lithium ion battery anodes. [ABSTRACT FROM AUTHOR]