A Biomineralization Strategy for “Net”‐Like Interconnected TiO₂ Nanoparticles Conformably Covering Reduced Graphene Oxide with Reversible Interfacial Lithium Storage

A green and simple biomineralization‐inspired method to create “net”‐like interconnected TiO₂ nanoparticles conformably covering reduced graphene oxide (RGO) with high loading density is reported. This method uses polyamine as both the biomineralization agent and linker to manipulate the nucleation, growth, and crystallization of TiO₂ nanoparticles on the surface of graphene oxide. The obtained TiO₂/RGO composites demonstrate sub‐10‐nm TiO₂ nanoparticles with (001) facets, ultrathin thickness (10–12 nm), and a high surface area of 172 m² g⁻¹. When used as anode material for lithium ion batteries, the material displayed excellent rate capability and long cycle life; a capacity of 155 mAh g⁻¹ is obtained after 50 cycles at the rate of 5C (1C = 168 mA g⁻¹) and a specific capacity of 115 mAh g⁻¹ is retained after 2000 cycles at the rate of 25C, which is much higher than that of mechanically mixed TiO₂/graphene composites. Detailed discharge curve analysis reveals that the high rate and cycle performance are partly a result of the reversible interfacial lithium storage of materials, which might be attributed to the pores in the TiO₂ nets on the RGO and may provide a sufficient number of interfaces for accepting both electrons and lithium ions.