Pillaring of a conductive polymer in layered V2O5 boosting ultra-fast Zn2+/H+ storage in aqueous media

• Published in: Electrochimica acta 2022-06, Vol.416, p.140270, Article 140270
• Main Authors: Wang, Wenjian, He, Dongxu, Fang, Yuan, Wang, Shuai, Zhang, Zidong, Zhao, Rui, Xue, Weidong
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Cathodes; Cations; Conducting polymers; Electrochemical impedance spectroscopy; Energy storage; H+/Zn2+ co-intercalation; Intercalation; Interlayers; Ion diffusion; Kinetics; Large interlayer spacing; Lithium; Lithium-ion batteries; Polypyrrole; Polypyrroles; Rechargeable batteries; Storage batteries; Titration; Vanadium pentoxide; Zinc-ion battery
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2022.140270

•Conducting polymer (polypyrrole)-intercalated V2O5 is synthesized by a simple hydrothermal technique.•Polypyrrole enlarges the layer spacing of V2O5 and forming a highway for ion diffusion.•Charge storage mechanism of Zn2+ and H+ co-intercalation layer is confirmed.•The electrode exhibits excellent electrochemical performance in aqueous zinc-ion batteries. Aqueous secondary zinc-ion batteries are promising candidates to replace lithium-ion batteries for large-scale energy storage, due to their high safety and low cost. However, the developed cathodes materials are facing low capacity or low cycle life due to sluggish diffusion kinetics. Therefore, the design of a cathode with ultrafast ion diffusion kinetics remains a great challenge. Here, we propose an in-situ intercalation strategy of polypyrrole to improve the cation diffusion kinetics of V2O5. The polypyrrole as a guest significantly enlarges the interlayer spacing, paving the ‘‘superhighway’’ for cation diffusion. In addition, thanks to the unique π-conjugated structure, polypyrrole can shield the electrostatic force of Zn2+ and the host oxygen-sublattice. The energy storage mechanism of the cathode was shown to be a stepwise H+/Zn2+co-intercalation by means of galvanostatic intermittent titration technique (GITT), electrochemical impedance spectroscopy (EIS) and ex situ X-ray diffraction (XRD). Based on the above advantages, the polypyrrole-intercalated V2O5 demonstrates high capacities and excellent cycling performance (220 mA h g−1 after 2000 cycles at 10 A g−1). We report an in-situ intercalation strategy of polypyrrole to improve the cation diffusion kinetics of V2O5. The polypyrrole as a guest significantly enlarges the layer spacing, paving the ‘‘superhighway’’ for Zn2+ and H+ diffusion. [Display omitted]