Ion‐Molecule Co‐Confining Ammonium Vanadate Cathode for High‐Performance Aqueous Zinc‐Ion Batteries

Abstract

Abstract Vanadium‐based cathode materials have attracted great attention in aqueous zinc‐ion batteries (AZIBs). However, the inferior ion transport and cyclic stability due to the strong Coulomb interaction between Zn 2+ and the lattice limit their further application. In this work, CO 2 molecules are in situ embedded in the interlayer structure of NH 4 V 4 O 10 by decomposing excess H 2 C 2 O 4 ·2H 2 O in the main framework, obtaining an ion‐molecule co‐confining NH 4 V 4 O 10 for AZIB cathode material. The introduced CO 2 molecules expanded the interlayer spacing of NH 4 V 4 O 10 , broadened the diffusion channel of Zn 2+ , and stabilized the structure of NH 4 V 4 O 10 as the interlayer pillars together with , which effectively improved the Zn 2+ diffusion kinetics and cycle stability of the electrode. In addition, the binding between and the host framework is stabilized via hydrogen bonds with CO 2 molecules. NVO‐CO 2 ‐0.8 exhibited excellent specific capacity (451.1 mAh g −1 at 2 A g −1 ), cycle stability (214.0 mAh g −1 at 10 A g −1 after 1000 cycles) and rate performance. This work provides new ideas and approaches for optimizing vanadium‐based materials with high‐performance AZIBs.