Hydrothermal synthesis of coherent porous V_2O_3/carbon nanocomposites for high-performance lithium-and sodium-ion batteries

Carbonaceous composite materials have been extensively studied in energy storage and conversion devices and commonly are fabricated from liquid precursors. In this work, we reported an unusual formation of vanadium oxide and carbon nanocomposite from microsized VO_2 microspheres through a ＂dissolution and recrystallization＂ process with the assistance of Li H_2PO_4. The obtained vanadium oxides nanoparticles are in uniform distribution in the carbon matrix. The V_2O_3/carbon composite inherits the porous feature of the Ketjen black（KB） carbon and has a surface area of 76.59m~2g~-1. As an anode material for lithium/sodium-ion batteries,the V_2O_3/carbon nanocomposites exhibit higher capacity,better rate capability and cycling stability than the V_2O_3 nanoparticle counterparts. The enhanced electrochemical performances are attributed to the porous V_2O_3/carbon nanocomposites, which can allow the electrolyte penetration,shorten the ion diffusion distance and improve the electronic conductivity.