▎ 摘　　要

It is still a considerable challenge for spinel Li4Ti5O12 to achieve high tap density while retaining excellent power capability. Herein, a compact and mesopore-oriented holey-graphene framework (HGF) caging nano-Li4Ti5O12 particles (Li4Ti5O12/HGF) is synthesized by capillary shrink effect. In the capillary drying process, nano-Li4Ti5O12 particles prevent the absolute aggregation of graphene sheets, remaining mesopore-oriented porosity for rapid Li+ diffusion. After precisely adjusting the porous structure, Li4Ti5O12/HGF composite successfully achieves a balance between tap density and porosity. Furthermore, the in-plane nanopores of holey-graphene sheets provide channels for Li+ diffusion, obviously weakening the Li+ diffusion resistances of compact composite. The resultant Li4Ti5O12/HGF composite combines a high tap density of 1.1 g cm(-3) and a moderate mesopore-oriented porosity with BET specific area of 152 m(2) g(-1), delivering volumetric-specific capacities of 161, 142, 120, 103 mA h cm(-3) at 0.035, 1.75, 7 and 14 A g(-1), respectively. Even as current density reaches 17.5 A g(-1), the as-prepared Li4Ti5O12/HGF composite still displays a capacity of 98 mA h cm(-3), showing excellent ultrahigh-rate performance. After 1000 cycles at 7A g(-1), the capacity of dense Li4Ti5O12/HGF composite remains 84%, demonstrating high cycle stability.