Tuning the electronic structure of layered vanadium pentoxide by pre-intercalation of potassium ions for superior room/low-temperature aqueous zinc-ion batteries

• Published in: Nanoscale Vol. 13; no. 4; pp. 2399 - 247
• Main Authors: Su, Guang, Chen, Shufeng, Dong, Huilong, Cheng, Yafei, Liu, Quan, Wei, Huaixin, Ang, Edison Huixiang, Geng, Hongbo, Li, Cheng Chao
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 04.02.2021
• Subjects: Cycles; Density functional theory; Diffusion layers; Electrochemical analysis; Electron microscopy; Electronic structure; Intercalation; Interlayers; Kinetics; Low temperature; Microscopy; Photoelectrons; Rechargeable batteries; Structural stability; Vanadium pentoxide
• ISSN: 2040-3364; 2040-3372; 2040-3372
• DOI: 10.1039/d0nr07358j

Aqueous zinc-ion batteries (ZIBs), due to their sluggish Zn 2+ diffusion kinetics, continue to face challenges in terms of achieving superior high rate, long-term cycling and low-temperature properties. Herein, K + pre-intercalated layered V 2 O 5 (K 0.5 V 2 O 5 ) composites with metallic features are capable of delivering excellent zinc storage performance. Specifically, the K 0.5 V 2 O 5 electrode delivers a high reversible capacity of 251 mA h g −1 at 5 A g −1 after 1000 cycles. Even at a low temperature of −20 °C, high reversible capacities of 241 and 115 mA h g −1 can be obtained after 1000 cycles at 1 and 5 A g −1 , respectively. The outstanding electrochemical performance is attributed to the incorporation of K + into the layered V 2 O 5 , which acts as pillars to promote the Zn 2+ diffusion and increase the structural stability during cycling. Density functional theory calculations demonstrate that the interlayer doping of K + can benefit electron migration, and therefore enhance the Zn 2+ (de)intercalation kinetics. Meanwhile, the Zn 2+ storage mechanism of K 0.5 V 2 O 5 is revealed by ex situ X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy characterization. This work may pave the way for exploiting high-performance cathodes for aqueous ZIBs. Aqueous zinc-ion batteries (ZIBs), due to their sluggish Zn 2+ diffusion kinetics, continue to face challenges in terms of achieving superior high rate, long-term cycling and low-temperature properties.