Pulling Effects of Interlayer Water Molecules Strengthen Dry‐swimming Zn <sup>2+</sup> Reaction Kinetics in Layered Vanadium Oxides
Ziyi Feng, Yifu Zhang, Yifu Zhang, Hao Yuan, Jianguo Sun, Changgong Meng, Yong‐Wei Zhang, Yong‐Wei Zhang, John Wang
Abstract
Abstract Layered vanadium pentoxides (V 2 O 5 ) have been widely studied as a class of competitive cathode materials for aqueous rechargeable zinc ion batteries (ARZIBs), arising from their multi‐possibilities in structural manipulation and electrochemical performance. Previous studies show that H 2 O moelcules interact with Zn 2+ to form solvation structures. In this way, the electrostatic interactions with the V─O layer are attenuated. Herein, the role of interlayer structural water molecules in influencing the electrochemical behavior of Zn 2 ⁺ ions is investigated through a “pulling effect”. This theoretical calculations demonstrate that the interlayer water molecules can also pull the pre‐intercalated K + ions into the defined inter‐layer space, which effectively prevents the floating of metal ions to the laminates during the repeated electrochemical reactions, and thus stabilize the overall structure. “Localized resolvalizated” reactions of coming Zn 2+ induced by the pulling effect between Zn 2+ and interlayer water molecules makes the fast diffusion efficiency for the dry‐swimming Zn 2+ ions. This experimental results confirm that KVOH gives rise to a high specific capacity of 525 mAh·g −1 at 0.1 A·g −1 , and delivers 252 mAh·g −1 after 2000 cycles at 4 A·g −1 , compared with only 29 mAh·g −1 remained for KV after 2000 cycles at 4 A·g −1 .