Low-Cost and Large-Scale Preparation of H₂O and Mg²⁺ Co-Preintercalated Vanadium Oxide with High-Performance Aqueous Zn-Ion Batteries

Abstract

Rechargeable zinc-ion batteries (ZIBs) are considered the most promising energy storage device to replace lithium-ion batteries (LIBs) due to their high security and environment-friendly feature. However, the synthesis of high-performance cathode materials usually requires harsh conditions (such as high temperature and high pressure), which limits the practical application of ZIBs. Herein, a facile large-scale preparation of H 2 O and Mg 2+ co-intercalated vanadium oxide is realized by heating vanadium pentoxide and magnesium sulfate solution in a water bath at low temperature. Through in-depth investigation, it is found that the introduced H 2 O and Mg 2+ not only expand the layer spacing of vanadium pentoxide but also improve the structural stability of V−O layers and ion diffusion. As a result, the obtained product displays an excellent specific capacity of 473 mAh g −1 at 0.1 A g −1 and superior cycle performance when used as the cathode material of ZIBs. Such a result indicates that H 2 O and Mg 2+ co-intercalated vanadium oxide shows a good application prospect.

K2[(VOHPO4)2(C2O4)]·2H2O as a high‐potential cathode material for potassium‐ion batteries

“…The hydrated variant, K 2 [(VOHPO 4 ) 2 (C 2 O 4 )]·2H 2 O (termed KVP‐H), possesses a crystal structure akin to that of KVP. In KVP‐H, water molecules situated in the interlayer potentially aid in mitigating volume fluctuations during potassium ion insertion/extraction processes and enhancing cycling performance 43,44 . However, due to the lack of suitable electrolytes with high oxidation stability, the electrochemical performance of KVP‐H as a cathode material for KIBs remains unexplored.…”