Interior Supported Hierarchical TiO₂@Co₃O₄ Derived from MOF‐on‐MOF Architecture with Enhanced Electrochemical Properties for Lithium Storage

Abstract

Abstract Metal‐organic frameworks (MOFs)‐derived materials are widely applied in functional materials with noble structures. Here, a well‐designed strategy for generating hierarchical double‐shelled nanoboxes is reported. Starting from the construction of hierarchical MOF‐on‐MOF architecture followed by a post‐annealing treatment, hierarchical TiO 2 @Co 3 O 4 nanoboxes are successfully synthesized with an interior TiO 2 shell supporting the outer hollow‐Co 3 O 4 ‐aggregates shell with a CoTiO 3 intermediate layer. The TiO 2 @Co 3 O 4 electrode displays a superior lithium storage performance in terms of high reversible capacity (920.5 mAh g −1 after 150 cycles at 200 mA g −1 , 58.6 % higher than theoretical capacity), outstanding high‐rate long‐term cycling stability (838.6 mAh g −1 after 600 cycles at 1000 mA g −1 , 44.5 % higher than theoretical capacity), and remarkable rate capability (good restorability at 2000 mA g −1 ). Furthermore, the morphology and electrochemical kinetic analysis proves that TiO 2 @Co 3 O 4 has a more stable structure, higher capacitive contribution, and better Li‐ion diffusion, which enhance the lithium‐storage performance.