Li3VO4 is a potential anode for Li‐ion batteries owing to its safe discharge plateau and high capacity, but the reported reversible capacity is still far from its theoretical value (592 mAh g−1). Here, for the first time, a Li3VO4 anode is reported with reversible capacity approaching the theoretical value. Li3VO4 aggregates hybridized with carbon (Li3VO4/C) are first fabricated, and then dramatically transform into well dispersed Li3VO4 nanocrystals (NCs) anchoring on carbon nanoflakes (NFs) by electrochemical reconstruction. In the Li3VO4/C NC‐on‐NF structures, the small‐sized Li3VO4 NCs, the flexible carbon NFs, and the good dispersity provide high Li‐ion storage, electronic conductivity and stability, respectively. Resultingly, outstanding electrochemical performance of the Li3VO4/C is achieved with discharge and charge capacities of 542 and 541 mAh g−1 after 300 cycles at a specific current of 150 mA g−1. After 1000 cycles at a specific current of 2000 mA g−1, the discharge and charge capacities are maintained at 422 and 421 mAh g−1. When matching with a 4 V cathode, the specific energy density of the Li3VO4/C is 4.2 times of Li4Ti5O12 and 1.2 times of graphite, and the volumetric energy density is 3.2 times of Li4Ti5O12 and 1.4 times of graphite.

Well-dispersed Fe3O4 nanocrystals were synthesized by a simple hydrothermal method. The as-synthesized products were characterized by field emission scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, x-ray diffraction, vibrating sample magnetometer and vector network analysis. The complex permittivity and permeability of paraffin wax and Fe3O4 with different Fe3O4 volume fractions were measured to increase linearly with the increase in the volume fraction of Fe3O4. The magnetic loss was caused mainly by natural resonance, which is in good agreement with the Kittel equation results. When the matching thickness is 3 mm, the calculated reflection loss reaches a maximum value of −21.2 dB at 8.16 GHz with 30% volume fraction of Fe3O4.

Ni(OH) 2 nanowalls were prepared via a novel hydrothermal method, which show excellent cycling stability as anodes for Li-ion batteries.The initial discharge and charge capacities are 0.63 and 0.49 mA h cm À2 , respectively, showing no evident capacity attenuation over 100 cycles.

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