Self-assembled Fe 3 O 4 nanoparticle-doped TiO 2 nanorod superparticles with highly enhanced lithium storage properties

Abstract

Rational design of nanostructured anode materials is of importance for promoting the performance of lithium ion batteries (LIBs). Here the Fe 3 O 4 nanoparticles (NPs) were controllably inserted into the matrix of TiO 2 nanorods (NRs) to obtain doped-superparticles (SPs) by a facile colloidal self-assembly route and subsequent calcination. To justify the effects of the doping, the lithium storage performances of the doped-SPs were evaluated as anode materials for LIBs. The results indicated that even a slight doping of Fe 3 O 4 NPs can effectively enhance the properties of the anode materials compared with raw TiO 2 NR SPs. Additionally, the Fe 3 O 4 /(TiO 2 ) 70 SPs showed an optimal performance in term of specific capacity, rate capacity, and cycling stability, whose reversible capacity maintained around 550 mA h g -1 at a current density of 1000 mA g -1 after 400 cycles. The highly enhanced lithium storage of the Fe 3 O 4 NP doped-TiO 2 NR SPs can substantially be attributed to the synergism of the doped-superstructure, in which the individual merits of the Fe 3 O 4 NPs and TiO 2 NRs are fully played out. This work not only demonstrates the significant effects of Fe 3 O 4 NP doping for TiO 2 NR SP anode materials in LIBs, but also opens an avenue for the self-assembly synthesis of doped-SPs with extended applications.