Ultrathin Li₄Ti₅O₁₂ Nanosheet Based Hierarchical Microspheres for High‐Rate and Long‐Cycle Life Li‐Ion Batteries

Ultrathin Li₄Ti₅O₁₂ nanosheet based hierarchical microspheres are synthesized through a three‐step hydrothermal procedure. The average thickness of the Li₄Ti₅O₁₂ sheets is only ≈(6.6 ± 0.25) nm and the specific surface area of the sample is 178 m² g⁻¹. When applied into lithium ion batteries as anode materials, the hierarchical Li₄Ti₅O₁₂ microspheres exhibit high specific capacities at high rates (156 mA h g⁻¹ at 20 C, 150 mA h g⁻¹ at 50 C) and maintain a capacity of 126 mA h g⁻¹ after 3000 cycles at 20 C. The results clearly suggest that the utility of hierarchical structures based on ultrathin nanosheets can promote the lithium insertion/extraction reactions in Li₄Ti₅O₁₂. The obtained hierarchical Li₄Ti₅O₁₂ with ultrathin nanosheets and large specific surface area can be perfect anode materials for the lithium ion batteries applied in high power facilities, such as electric vehicles and hybrid electric vehicles.