Synergism of Preintercalated Manganese Ions and Lattice Water in Vanadium Oxide Cathodes for High-Capacity and Long-Life Zn-ion Batteries

Aqueous Zn-ion batteries (AZIBs) are recognized as a promising energy storage system with intrinsic safety and low cost, but its applications still rely on the design of high-capacity and stable-cycling cathode materials. In this work, we present an intercalation mechanism-based cathode materials for AZIB, i.e. the vanadium oxide with pre-intercalated manganese ions and lattice water (noted as MVOH). The synergistic effect between Mn2+and lattice H2O not only expands the interlayer spacing, but also significantly enhances the structural stability. Systematic in -situ and ex -situ characterizations clarify the Zn2+/H+ co-(de)intercalation mechanism of MVOH in aqueous electrolyte. The demonstrated remarkable structure stability, excellent kinetic behaviors and ion-storage mechanism together enable the MVOH to demonstrate satisfactory specific capacity of 450 mA h g-1 at 0.2 A g-1, excellent rate performance of 288.8 mA h g-1 at 10 A g-1 and long cycle life over 20,000 cycles at 5 A g-1. This work provides a practical cathode material, and contributes to the understanding of the ion-intercalation mechanism and structural evolution of the vanadium-based cathode for AZIBs. (c) 2024 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies./License if selected.