In‐Situ Lattice Tunnel Intercalation of Vanadium Pentoxide for Improving Long‐Term Performance of Rechargeable Magnesium Batteries
Jun Yang, Xiaowei Miao, Chenrui Zhang, Jihui Zheng, Chencheng Sun, Yu Zhang, Hongbo Geng
Abstract
Abstract Layered V 2 O 5 is a promising and versatile cathode for rechargeable magnesium batteries (RMBs), but its narrow interlayer spacing makes rapid Mg 2+ diffusion difficult, resulting in poor electrochemical performance. Herein, a facile and scalable technique is established for tailoring the (001) spacing of V 2 O 5 by in‐situ polyaniline polymerization. The intercalated polyaniline molecules operate as pillars in the V 2 O 5 interlayer, providing plentiful storage sites as well as improved cation diffusivities of Mg ion. As expected, by using V 2 O 5 /polyaniline as the cathode (anode: Mg metal), a high specific capacity of 361 mAh g −1 with charging/discharging current density of 20 mA g −1 can be achieved for RMBs. Besides, V 2 O 5 /polyaniline electrode shows favorable rate capability with 103 mAh g −1 at 500 mA g −1 (500 cycles) and ultra long‐term cycling performance after 5000 cycles. Ex situ X‐ray photoelectron spectroscopy is used to study the magnesium storage mechanism of the V 2 O 5 /polyaniline electrode.