Interconnected Ultrasmall V₂O₃ and Li₄Ti₅O₁₂ Particles Construct Robust Interfaces for Long-Cycling Anodes of...

Designing composite structures of active materials is critical for high-performance lithium-ion batteries, as it determines the reversibility of lithium-ion insertion and extraction of the electrodes. The V₂O₃ anode has a high specific capacity but presents poor cycling stability due to a large volume change. Herein, a novel C@V₂O₃-Li₄Ti₅O₁₂ composite with ultrastable cycling stability is constructed. In this composite structure, the interconnected ultrasmall V₂O₃ and Li₄Ti₅O₁₂ nanoparticles (5-10 nm) construct robust interfaces in the carbon matrix. The Li₄Ti₅O₁₂ nanoparticles with excellent cycling stability and a minor volume change act as fixtures that effectively restrict the volume change of V₂O₃ nanoparticles and improve the cycling stability of the C@V₂O₃-Li₄Ti₅O₁₂ composite. The C@V₂O₃-Li₄Ti₅O₁₂ composite maintains no degradation during 500 cycles under a current density of 100 mA g^-1. The results demonstrate that constructing a highly stable interface between the active nanoparticles with smaller and larger volume changes is of great significance to suppress their pulverization and achieve high reversibility. This work contributes to a new strategy to design the structure of long-cycling anode materials for highly stable lithium-ion batteries.