Vanadium Oxide Intercalated with Conductive Metal–Organic Frameworks with Dual Energy‐Storage Mechanism for High Capacity and High‐Rate Capability Zn Ion Storage

Abstract

Vanadium oxides (VO_x) feature the potential for high‐capacity Zn²⁺ storage, which are often preintercalated with inert ions or lattice water for accelerating Zn²⁺ migration kinetics. The inertness of these preintercalated species for Zn²⁺ storage and their incapability for conducting electrons, however, compromise the capacity and rate capability of VO_x. Herein, Ni‐BTA, a 1D conductive metal–organic framework (c‐MOF), is intercalated into the interlayer space of VO_x by coordinating organic ligands with preinserted Ni²⁺. The intercalated Ni‐BTA improves the conductivity of VO_x by π–d conjugation, facilitates Zn²⁺ migration by enlarging its interlayer spacing, and stabilizes the crystal structure of VO_x as interlayer pillars, thus simultaneously enhancing the material's rate capability and cycling stability. Meanwhile, a dual reaction mechanism of Zn²⁺ storage, i.e., the redox of V⁵⁺/V³⁺ in VO_x and the rearrangement of chemical bonds (CN/CN) in Ni‐BTA, collaboratively contributes to an enhanced capacity. Consequently, this Ni‐BTA‐intercalated VO_x material exhibits a high Zn²⁺ storage capacity of 464.2 mAh g⁻¹ at 0.2 A g⁻¹ and an excellent rate capability of 272.5 mAh g⁻¹ at 5 A g⁻¹. This work provides a general strategy for integrating c‐MOFs with inorganic cathode materials to achieve high‐capacity and high‐rate performance.