Fast and Durable Lithium Storage Enabled by Tuning Entropy in Wadsley–Roth Phase Titanium Niobium Oxides

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2023-07-26
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Mcode
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Language
en
Pages
14
Series
Small, Volume 19, issue 30
Abstract
Wadsley–Roth phase titanium niobium oxides have received considerable interest as anodes for lithium ion batteries. However, the volume expansion and sluggish ion/electron transport kinetics retard its application in grid scale. Here, fast and durable lithium storage in entropy-stabilized Fe0.4Ti1.6Nb10O28.8 (FTNO) is enabled by tuning entropy via Fe substitution. By increasing the entropy, a reduction of the calcination temperature to form a phase pure material is achieved, leading to a reduced grain size and, therefore, a shortening of Li+ pathway along the diffusion channels. Furthermore, in situ X-ray diffraction reveals that the increased entropy leads to the decreased expansion along a–axis, which stabilizes the lithium intercalation channel. Density functional theory modeling indicates the origin to be the more stable Fe-O bond as compared to Ti-O bond. As a result, the rate performance is significantly enhanced exhibiting a reversible capacity of 73.7 mAh g−1 at 50 C for FTNO as compared to 37.9 mAh g−1 for its TNO counterpart. Besides, durable cycling is achieved by FTNO, which delivers a discharge capacity of 130.0 mAh g−1 after 6000 cycles at 10 C. Finally, the potential impact for practical application of FTNO anodes has been demonstrated by successfully constructing fast charging and stable LiFePO4‖FTNO full cells.
Description
Funding Information: J.Z. and R.X. contributed equally to this work. J.Z., R.X., and Q.Q. acknowledge the financial support of the China Scholarships Council (CSC) program, no. 201906150132, no. 201807720013, and no. 201906150134, respectively. The STEM analysis was supported by the National Natural Science Foundation of China (22005230). Publisher Copyright: © 2023 The Authors. Small published by Wiley-VCH GmbH.
Keywords
entropy, fast charging, iron substitution, lithium-ion batteries, Wadsley–Roth phase
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Citation
Zheng, J, Xia, R, Sun, C, Yaqoob, N, Qiu, Q, Zhong, L, Li, Y, Kaghazchi, P, Zhao, K, Elshof, J E T & Huijben, M 2023, ' Fast and Durable Lithium Storage Enabled by Tuning Entropy in Wadsley–Roth Phase Titanium Niobium Oxides ', Small, vol. 19, no. 30, 2301967 . https://doi.org/10.1002/smll.202301967