Tailored sonochemical synthesis of V2O5|graphene nanoplatelets composites and its enhanced Li-ion insertion properties

Abstract

Ultrasound-assisted surface modification of graphene nanoplatelets (GNPs) has made possible for in situ growth of V2O5 nanoparticles; homogeneously decorating inter-connected two-dimensional GNPs. The as-fabricated One-Step V2O5|GNPs nanocomposite exhibited enhanced electronic conductivity and facilitates higher Li+ ion insertion/ extraction kinetics, attained the high capacity of 297 mA h g−1 (10 mA g−1) corresponding to ∼2 Li+ ion insertion/ extraction. Consequently, the sonochemically tailored One-Step V2O5|GNPs nanocomposite delivered the specific capacity of 248 mA h g−1 at 50 mA g−1 with 83% capacity retention and 98.4% coulombic efficiency for the cycling studies. In addition, the rate capability studies were extended to One-Step V2O5|GNPs cathode at different current density from 10 to 200 mA g-1. On the other hand, the Two-Step (sonochemical synthesis of 200 nm V2O5 particles followed by its deposition on GNPs) V2O5|GNPs composite cathode yielded less specific capacity of 225 mA h g−1 (10 mA g-1) than the One-Step V2O5|GNPs nanocomposite cathode.