Elaborately Designed Hierarchical Heterostructures Consisting of Carbon-Coated TiO2(B) Nanosheets Decorated with Fe3O4 Nanoparticles for Remarkable Synergy in High-Rate Lithium Storage

The capacity and conductivity deficiencies of TiO2(B) are addressed simultaneously through a smart morphological and compositional design. Elaborately designed hierarchical heterostructures are reported, consisting of carbon-coated TiO2(B) nanosheets decorated with Fe3O4 nanoparticles, based on a facile self-assembly strategy. The novel hierarchical heterostructures exhibit a remarkable synergy by bridging the intriguing functionalities of TiO2(B) nanosheets (high safety and durability), Fe3O4 nanoparticles (high theoretical capacity), and carbon coatings (high conductivity), which results in significantly improved cycle and rate performances. A startlingly high reversible capacity of 763 mA h g(-1) is delivered at 500 mA g(-1) after 200 charging-discharging cycles. Even when the current density is as high as 10 000 mA g(-1), the reversible capacity is still up to 498 mA h g(-1). This smart morphological and compositional design opens up new opportunities for developing novel, multifunctional hierarchical heterostructures as promising anode materials for next-generation, high-power lithium-ion batteries.