Template-Free Synthesis of Cobalt Silicate Nanoparticles Decorated Nanosheets for High Performance Lithium Ion Batteries

Transition metal silicates as anode materials for lithium ion batteries (LIBs) have drawn increasing attention because of their high theoretical capacity, abundance in nature, thermal stability and nontoxicity. Among them, Co₂SiO₄ is particularly promising. Herein, hierarchical amorphous Co₂SiO₄ nanosheets coated with nanoparticles were prepared by a template-free one-pot hydrothermal method. Co₂SiO₄ nanoparticles (∼20 nm) are uniformly deposited on ultrathin Co₂SiO₄ nanosheets. The method avoids prefabricating template compared with hydrothermal method, the nanostructure obtained is also superior than that obtained through the traditional high temperature sintering approach. As lithium ion battery anode, the hierarchical Co₂SiO₄ electrode delivers a high capacity of about 1410 mAh g^-1 after 100 cycles (current density: 100 mA g^-1). Even at 5 A g^-1, a specific capacity of 670 mAh g^-1 can be maintained after 1500 cycles. The excellent battery performance may be attributed to the synergistic effect between the nanoparticles and nanosheets of Co₂SiO₄.