CoWO4 nanopaticles wrapped by RGO as high capacity anode material for lithium ion batteries

Transition-metal oxides have attracted increased attention in the application of high-performance lithium ion batteries (LIBs), owing to its higher reversible capacity, better structural stability and high electronic conductivity. Herein, CoWO4 nanoparticles wrapped by reduced graphene oxide (CoWO4–RGO) were synthesized via a facile hydrothermal route followed by a subsequent heat-treatment process. When evaluated as the anode of LIB, the synthetic CoWO4–RGO nanocomposite exhibits better Li+ storage properties than pure CoWO4 nanostructures synthesized without graphene oxide (GO). Specifically, it delivers a high initial specific discharge capacity of 1100 mAh·g−1 at a current density of 100 mA·g−1, and a good reversible performance of 567 mAh·g−1 remains after the 100th cycle. Moreover, full battery using CoWO4–RGO as anode and commercial LiCoO2 powder as cathode was assembled, which can be sufficient to turn on a 3 V, 10 mW blue light emitting diode (LED). The enhanced electrochemical performance for lithium storage can be attributed to the three-dimensional (3D) structure of the CoWO4–RGO nanocomposite, which can accommodate huge volume changes, and synergetic effect between CoWO4 and reduced graphite oxide (RGO) nanosheets, including an increased conductivity, shortened Li+ diffusion path.