•Carbon-coated Li3VO4 embedded in expanded graphite has been synthesized at one step.•High electronic conductivity and mechanical stability are obtained.•Rate and cycling performance largely improved as for lithium ion battery.A hierarchical structure of carbon-coated Li3VO4 nanoparticles homogeneously embedded in expanded graphite was successfully synthesized by a facile and scalable sol–gel method. In the constructed architecture, high electronic conductivity of expanded graphite serves as a loading carrier, enabling the fast transmission of electronics. The thin outside carbon shells protect the Li3VO4 nanoparticles from direct exposure to the electrolyte and mitigate unwanted interfacial side reactions. As a consequence, the hybrid material exhibits greatly enhanced cycle and rate capability compared with pristine Li3VO4: a reversible gravimetric capacity of 405 mAh g−1 obtained at 100 mA g−1 with 89% retention after 200 cycles, and 205.5 mAh g−1 obtained after 2000 cycles at a heavy current of 2000 mA g−1, as well as an remarkable rate performance of 62.7% capacity maintaining at 6400 mA g−1 (vs. 100 mA g−1).

•A nano-sized Si/graphene composite was prepared by magnesium thermal reducing of the in-situ generated SiO2 on graphene sheets.•The Si/graphene composite delivers large reversible capacity with excellent cycling stability.•The graphene and nanospaces between Si nanoparticles could accommodate volume expansion during lithium insertion and extraction.A nanosized Si/graphene composite was prepared by magnesium thermal reduction of the in-situ generated SiO2 particles on graphene sheets, in which about 5 nm-silicon nanoparticles were homogeneously loaded on graphene sheets. The unique structure can not only accommodate the large volume changes, but also maintain electronic conductivity during Li-ion insertion/extraction. The composite delivers an initial reversible capacity of 1750 mAh/g at a current rate of 100 mA/g and exhibits an excellent cycling stability with a capacity of 1374 mAh/g over 120 cycles.

A series of pitch modified hard carbons was prepared using coal-tar pitch and phenolic resin as carbon precursors. The effects of the amount of the soft carbon from pitch precursor, varying from 0 wt% to 40 wt%, and heat-treatment temperature in the range from 900 °C to 1800 °C, on their electrochemical performance were systemically studied, including the reversible capacity, coulombic efficiency in the first cycle, the rate capability and cycling stability. Under the optimal condition, the carbon material obtained at 1200 °C with 30 wt% soft carbon as negative material for lithium-ion batteries exhibits a reversible capacity of about 290 mAh g−1 at a constant current density of 0.5 mA cm−2 with excellent rate capability and cycling stability.

In the present work, an interconnected sandwich carbon/Si-SiO2/carbon nanospheres composite was prepared by template method and carbon thermal vapor deposition (TVD). The carbon conductive layer can not only efficiently improve the electronic conductivity of Si-based anode, but also play a key role in alleviating the negative effect from huge volume expansion over discharge/charge of Si-based anode. The resulting material delivered a reversible capacity of 1094 mAh/g, and exhibited excellent cycling stability. It kept a reversible capacity of 1050 mAh/g over 200 cycles with a capacity retention of 96%.The interconnected sandwich carbon/Si-SiO2/carbon nanospheres composite exhibits good battery profile with a reversible capacity of 1094 mAh/g and a reversible capacity of 1050 mAh/g over 200 cycles with a capacity retention of 96%.Download full-size image