文章基本信息

标题：Orthorhombic Nb 2O 5- x for Durable High-Rate Anode of Li-Ion Batteries
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作者：Zichao Liu ; Wujie Dong ; Jianbo Wang 等
期刊名称：iScience
印刷版ISSN：2589-0042
出版年度：2020
卷号：23
期号：1
页码：1-28
DOI：10.1016/j.isci.2019.100767
语种：English
出版社：Elsevier
摘要：SummaryLi4Ti5O12anode can operate at extraordinarily high rates and for a very long time, but it suffers from a relatively low capacity. This has motivated much research on Nb2O5as an alternative. In this work, we present a scalable chemical processing strategy that maintains the size and morphology of nano-crystal precursor but systematically reconstitutes the unit cell composition, to build defect-rich porous orthorhombic Nb2O5-xwith a high-rate capacity many times those of commercial anodes. The procedure includes etching, proton ion exchange, calcination, and reduction, and the resulting Nb2O5-xhas a capacity of 253 mA h g−1at 0.5C, 187 mA h g−1at 25C, and 130 mA h g−1at 100C, with 93.3% of the 25C capacity remaining after cycling for 4,000 times. These values are much higher than those reported for Nb2O5and Li4Ti5O12, thanks to more available surface/sub-surface reaction sites and significantly improved fast ion and electron conductivity.Graphical AbstractDisplay OmittedHighlights•A novel micro-etching strategy is developed to prepare porous nano-crystal Nb2O5•The obtained Nb2O5remains the morphology of the precursor but reconstructs unit cell•Oxygen vacancies and Nb4+/Nb5+are introduced to porous Nb2O5-xby anoxic annealing•Defect-rich and porous Nb2O5-xworks as durable, high-rate, and safe anode of LIBsEnergy Storage; Chemical Synthesis; Energy Materials