Design of meso/macro porous 2D Mn-vanadate as potential novel anode materials for sodium-ion storage

In this study, flake-like sheets (S-MVO) and flowers-like MnV₂O₆ (F-MVO) anode materials are synthesized by a facile hydrothermal technique for the first time applied to Na-ion storage. In order to better understand the behavior of Na atoms in the structure of MnV₂O₆, ab-initio methods predict for convenient migration paths. Additionally, first-principle calculations are used to determine the electronic and optical properties. The steady reversible discharge capacity exhibits 348 mAh g⁻¹ for S-MVO electrode and 231 mAh g⁻¹ for F-MVO electrode at a current density of 100 mA/g over the 50 cycles. The stable reversible capacity ascribed from conversion with combination of intercalation/deintercalation reaction. The S-MVO sample demonstrates significant electrochemical performance without any hybridizing of carbonaceous materials. The mesoporous thin morphology provides enhanced kinetics activity, which suggests facilitating the electronic/ionic transfer. Thus, the simple manner of Na⁺ migration path prediction, cost-effective route of bi-metal mixed novel materials may open a way for the design of potential electrodes for commercial and future large-scale high-performance Na-ion energy storage devices.