Optimizing interplanar spacing, oxygen vacancies and micromorphology via lithium-ion pre-insertion into ammonium vanadate nanosheets for advanced cathodes in aqueous zinc-ion batteries

Chen, J. et al. (2024) Optimizing interplanar spacing, oxygen vacancies and micromorphology via lithium-ion pre-insertion into ammonium vanadate nanosheets for advanced cathodes in aqueous zinc-ion batteries. Small, (doi: 10.1002/smll.202309412) (Early Online Publication)

Abstract

Ammonium vanadates, featuring an N─H···O hydrogen bond network structure between NH4+ and V─O layers, have become popular cathode materials for aqueous zinc-ion batteries (AZIBs). Their appeal lies in their multi-electron transfer, high specific capacity, and facile synthesis. However, a major drawback arises as Zn2+ ions tend to form bonds with electronegative oxygen atoms between V─O layers during cycling, leading to irreversible structural collapse. Herein, Li+ pre-insertion into the intermediate layer of NH4V4O10 is proposed to enhance the electrochemical activity of ammonium vanadate cathodes for AZIBs, which extends the interlayer distance of NH4V4O10 to 9.8 Å and offers large interlaminar channels for Zn2+ (de)intercalation. Moreover, Li+ intercalation weakens the crystallinity, transforms the micromorphology from non-nanostructured strips to ultrathin nanosheets, and increases the level of oxygen defects, thus exposing more active sites for ion and electron transport, facilitating electrolyte penetration, and improving electrochemical kinetics of electrode. In addition, the introduction of Li+ significantly reduces the bandgap by 0.18 eV, enhancing electron transfer in redox reactions. Leveraging these unique advantages, the Li+ pre-intercalated NH4V4O10 cathode exhibits a high reversible capacity of 486.1 mAh g−1 at 0.5 A g−1 and an impressive capacity retention rate of 72% after 5,000 cycles at 5 A g−1.

• Item Type: Articles
• Additional Information: This work was supported by National College Students’ innovation and entrepreneurship training program (202310636004), Natural Science Foundation of Sichuan Province (2022NSFSC0222) and Sichuan Science and Technology Program (2023NSFSC0439).
• Status: Early Online Publication
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Lam, Dr Koko
• Authors: Chen, J., Zhai, Y., Li, Y., Zhang, X., Zhang, X., Chen, Y., Zeng, Y., Wu, X., Zheng, Q., Lam, K.-H., Tan, X., and Lin, D.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Small
• Publisher: Wiley
• ISSN: 1613-6810
• ISSN (Online): 1613-6829
• Published Online: 11 February 2024
• Copyright Holders: Copyright © 2024 The Authors
• First Published: First published in Small 2024
• Publisher Policy: Reproduced under a Creative Commons license