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

Abstract

AbstractVanadium oxides (VOx) 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 VOx. Herein, Ni‐BTA, a 1D conductive metal–organic framework (c‐MOF), is intercalated into the interlayer space of VOx by coordinating organic ligands with preinserted Ni2+. The intercalated Ni‐BTA improves the conductivity of VOx by π–d conjugation, facilitates Zn2+ migration by enlarging its interlayer spacing, and stabilizes the crystal structure of VOx 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 VOx and the rearrangement of chemical bonds (CN/CN) in Ni‐BTA, collaboratively contributes to an enhanced capacity. Consequently, this Ni‐BTA‐intercalated VOx 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.