A Low-Cost SiO x /C@Graphite Composite Derived from Oat Husk as an Advanced Anode for High-Performance Lithium-Ion Batteries

Silicon monoxide (SiO _x ), as a promising anode for the next-generation high-power lithium-ion batteries, has some advantages such as higher lithium storage capacity (∼2400 mAh g^-1), suitable working potential, and smaller volume variations during cycling compared with pure silicon. However, its disadvantages such as its inherent low conductivity and high cost impede its extensive applications. Herein, we have developed a low-cost and high-capacity SiO _x /C@graphite (SCG) composite derived from oat husks by a simple argon/hydrogen reduction method. For further practical application, we also investigated the electrochemical performances of SiO _x mixed with different ratios of graphite. As an advanced anode for lithium-ion batteries, the SCG-1 composite exhibits an excellent electrochemical performance in terms of lithium storage capacity (809.5 mAh g^-1 at 0.5 A g^-1 even after the 250th cycle) and high rate capability (479.7 mAh g^-1 at 1 A g^-1 after the 200th cycle). This work may pave the way for developing a low-cost silicon-based anode derived from biomass with a large reversible capacity and long cycle life in lithium-ion batteries.

Preparation of ultrathin carbon-coated CdS nanobelts for advanced Li and Na storage

In this paper, we report a simple hydrothermal method for preparation of ultrathin carbon-coated CdS (CdS@C) nanobelts. The CdS@C nanobelts show superior electrochemical properties as an anode material for Li-ion batteries. The optimized CdS@C composites deliver a reversible capacity around 910 mAhg^-1 and 48 mAhg^-1 at 0.1 Ag^-1 and 30.0 Ag^-1, respectively. Moreover, the optimized nanobelts are also potential materials for Na storage. A stable capacity around 240 mAhg^-1 is obtained at 0.1 Ag^-1, even after 100 cycles.

A Low-Cost and High-Capacity SiO x /C@graphite Hybrid as an Advanced Anode for High-Power Lithium-Ion Batteries

Silicon suboxide (SiO _x ) is one of the most promising anodes for the next-generation high-power lithium-ion batteries because of its higher lithium storage capacity than current commercial graphite, relatively smaller volume variations than pure silicon, and appropriate working potential. However, the high cost, poor cycling stability, and rate capability hampered its industrial applications due to its complex production process, volume changes during Li⁺ insertion/extraction, and low conductivity. Herein, a low-cost and high-capacity SiO _x /C@graphite (SCG) hybrid was designed and synthesized by a facile one-pot carbonization/hydrogen reduction process of the rice husk and graphite. As an advanced anode for lithium-ion batteries, the SiO _x /C@graphite hybrid delivers a high reversible capacity with significantly enhanced cycling stability (842 mAh g^-1 after 300 cycles at 0.5 A g^-1) and rate capability (562 mAh g^-1 after 300 cycles at 1 A g^-1). The great improvement in performances could be attributed to the positive synergistic effect of SiO _x nanoparticles as lithium storage active materials, the in situ-formed carbon matrix network derived from biomass functioning as an efficient three-dimensional conductive network and spacer to improve the rate capability and buffer the volume changes, and graphite as a conductor to further improve the rate capabilities and cycling stability by increasing the conductivity. The low-cost and high-capacity SCG derived from rice husk synthesized by a facile, scalable synthetic method turns out to be a promising anode for the next-generation high-power lithium-ion batteries.

Co9S8 nanoparticles embedded into amorphous carbon as anode materials for lithium-ion batteries

In this paper, Co9S8 nanoparticles embedded into amorphous carbon have been synthesized by a simple electrospinning method followed by a high-temperature annealing process. The unique structure endows the Co9S8/C composites with excellent electrochemical properties. Co9S8 particles embedded into the carbon matrix show a high Li storage capacity around 1100 and 358 mAhg-1 at a current density of 0.1 and 5.0 Ag-1, respectively. After 200 cycles, an impressive discharge capacity of around 1063.4 mAhg-1 can be obtained at a current density of 0.3 Ag-1.