Porous Nb4W7O31 microspheres with a mixed crystal structure for high-performance Li+ storage
Xingxing Jin, Qiang Yuan, Xiaolin Sun, Xuehua Liu, Jianfei Wu, Chunfu Lin
Correspondence Address: Prof./Dr. Chunfu Lin, Institute of Materials for Energy and Environment, College of Materials Science and Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071, China. E-mail: firstname.lastname@example.org; ORCID: 0000-0003-0251-7938. Prof./Dr. Jianfei Wu, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China; Shandong Energy Institute, 189 Songling Road, Qingdao 266101, China; Qingdao New Energy Shandong Laboratory, 189 Songling Road, Qingdao 266101, China. Email: email@example.com; ORCID: 0000-0002-1420-3947
Received: 1 Sep 2023 | Revised: 29 Oct 2023 | Accepted: 13 Nov 2023
© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/
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Niobium–tungsten oxides with tungsten bronze and confined ReO3 crystal structures are prospective anode candidates for lithium-ion batteries since the multi-electron transfer per niobium/tungsten offers large specific capacities. To combine the merits of the two structures, porous Nb4W7O31 microspheres constructed by nanorods are synthesized based on a facile solvothermal method. This new material contains different tungsten bronze structures and 4×4 ReO3-type blocks confined by tungsten bronze matrices, generating plenty of pentagonal and quadrangular tunnels for Li+ storage, as confirmed by spherical-aberration-corrected scanning transmission electron microscopy. Such structural mixing enables three-dimensionally uniform and small lattice expansion/shrinkage during lithiation/delithiation, leading to good structural and cyclic stability (95.2% capacity retention over 1500 cycles at 10C). The large interlayer spacing (~3.95 Å) coupled with the abundant pentagonal/quadrangular tunnels results in ultra-high Li+ diffusion coefficients (1.24×10–11 cm2 s–1 during lithiation and 1.09×10–10 cm2 s–1 during delithiation) and high rate capability (10C vs. 0.1C capacity retention percentage of 47.6%). Nb4W7O31 further exhibits a large reversible capacity (252 mAh g–1 at 0.1C), high first-cycle Coulombic efficiency (88.4% at 0.1C) and safe operating potential (~1.66 V vs. Li/Li+). This comprehensive study demonstrates that the porous Nb4W7O31 microspheres are a very promising anode material for future use in high-performance Li+ storage.
Porous Nb4W7O31 microsphere; tungsten bronze crystal structure, confined ReO3 crystal structure, in-situ XRD, Li+-storage mechanism
Cite This Article
Jin x, Yuan Q, Sun X, Liu X, Wu J, Lin C. Porous Nb4W7O31 microspheres with a mixed crystal structure for high-performance Li+ storage. Energy Mater 2023;3:[Accept]. http://dx.doi.org/10.20517/energymater.2023.68