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Silicon is a promising anode material for high-performance Li-ion batteries as a result of its high theoretical specific capacity and elemental abundance. Currently, the commercial application of the Si-based anode is still restricted by its large volume changes during the lithiation cycles and low electrical conductivity. To address these issues, we demonstrate a facile plasma-assisted discharge process to anchor nano-sized Si particles into methanol with quick quenching. After the subsequent sintering process, we obtained a Si/SiC/C composite (M-Si). The unique structure not only allowed for the electrolyte infiltration to enhance lithium ion diffusion during charge and discharge process, but also buffered the volume expansion of silicon particles to enhance the rate capability and cycle stability. The M-Si cell electrochemical results exposed good Li-ion storage performance compared to that of the bare Si used cell (B-Si). The electrode cell consisting of M-Si exhibited remarkable enhanced cyclic stability and sustained the reversible specific capacity of 563 mAhg -1 after 100 cycles, with a coulombic efficiency of 99% at a current density of 0.1C, which is higher than that of the B-Si electrode cell that was used. Hence, the as-prepared Si/SiC/C composite is an efficient anode material for Li-ion battery applications. Moreover, these results indicate that the novel plasma-assisted discharge technique will bring a potential durable methodology to produce novel high-performance electrode materials for future advanced large-scale energy-storage applications.

Binary mixed transition-based metal oxides have some of the most potential as anode materials for rechargeable advanced battery systems due to their high theoretical capacity and tremendous electrochemical performance. Nonetheless, binary metal oxides still endure low electronic conductivity and huge volume expansion during the charge/discharge processes. In this study, we synthesized a reduced graphene oxide (rGO)-wrapped CoV 2 O 4 material as the anode for sodium ion batteries. The X-ray diffraction analyses revealed pure-phased CoV 2 O 4 (CVO) rGO-wrapped CoV 2 O 4 (CVO/rGO) nanoparticles. The capacity retention of the CVO/rGO composite anode demonstrated 81.6% at the current density of 200 mA/g for more than 1000 cycles, which was better than that of the bare one of only 73.5% retention. The as-synthesized CVO/rGO exhibited remarkable cyclic stability and rate capability. The reaction mechanism of the CoV 2 O 4 anode with sodium ions was firstly studied in terms of cyclic voltammetry (CV) and ex situ XRD analyses. These results articulated the manner of utilizing the graphene oxide-coated spinel-based novel anode-CoV 2 O 4 as a potential anode for sodium ion batteries.

A series of Na 3-x V 2 (PO 4-x F x ) 3 (x = 0, 0.1, 0.15 and 0.3) polyanion cathode materials are synthesized via a sol-gel method. The optimal doping concentration of F in Na 3 V 2 (PO 4 ) 3 is 0.15 mol %. By neutron powder diffraction data, the chemical composition of as-synthesized material is Na 2.85 V 2 (PO 3.95 F 0.05 ) 3 . The half-cell of Na 2.85 V 2 (PO 3.95 F 0.05 ) 3 cathode exhibits a stable discharge capacity of 103 mAh g -1 and 93% of capacity retention over 250 cycles without decay at 0.1 A g -1 , which is higher than that of bare Na 3 V 2 (PO 4 ) 3 (98 mAh g -1 ). The high rate capability of Na 2.85 V 2 (PO 3.95 F 0.05 ) 3 is also dramatically enhanced via increase the conductivity of host material by F-doping. Moreover, the symmetrical Na-ion full-cell is fabricated using Na 2.85 V 2 (PO 3.95 F 0.05 ) 3 as cathode and anode materials. It is achieved that the good reversibility and superior cycling stability about 98% of capacity retention with ~100% of coulombic efficiency at 1.0 A g -1 throughout 1000 cycles. These results demonstrate that the optimal amount of Na 2.85 V 2 (PO 3.95 F 0.05 ) 3 is a distinctive potential candidate for excellent long-term cyclic stability with high rate low-cost energy storage applications.