“Three‐in‐One” Strategy that Ensures V<sub>2</sub>O<sub>5</sub>·<i>n</i>H<sub>2</sub>O with Superior Zn<sup>2+</sup> Storage by Simultaneous Protonated Polyaniline Intercalation and Encapsulation
Jingjing Sun, Yunfeng Zhao, Yanyan Liu, Hanmei Jiang, Chi Huang, Miao Cui, Tao Hu, Changgong Meng, Yifu Zhang
Abstract
The structural engineering of vanadium oxides is considered as a research hotspot for enhancing their electrochemical performances applied to aqueous zinc‐ion batteries (AZIBs). In regard to the laggard Zn 2+ transfer kinetic and fragile structure of V 2 O 5 · n H 2 O, herein, a feasible “three‐in‐one” strategy is adopted to design the structural engineering of V 2 O 5 · n H 2 O nanobelts through simultaneous protonated polyaniline intercalation and encapsulation (denoted as P‐VOH@P) to boost their Zn 2+ storage. First, the enlarged interlayer pillared by polyaniline accelerates Zn 2+ transfer speed and weakens electrostatic attraction between negative [VO] units and positive Zn 2+ . Second, polyaniline shell directly stabilizes the P‐VOH@P heterostructure. Third, the composition of protonated polyaniline not only improves the conductivity, but also contributes partial capacity though the reversible intrachain electronic migration. As expected, the Zn//P‐VOH@P cell exhibits specific capacities of 387 mAh g −1 with low‐mass‐loading cathode (2 mg cm −2 ) and 345 mAh g −1 with high‐mass‐loading cathode (5 mg cm −2 ) in coin cells and 360 mAh g −1 in pouch cells at 0.1 A g −1 . Furthermore, the Zn//P‐VOH@P cell shows low capacity decay and good rate property. Herein, light is shed on a new strategy of engineering the vanadium oxide structure for postgeneration cathode material and paves a novel way to the advanced energy‐storage system.