Structural properties and electrochemical performance of different polymorphs of Nb2O5 in magnesium-based batteries

• 作者: Cunyuan Pei Yameng Yin Xiaobin Liao Fangyu Xiong Qinyou An Mengda Jin Yan Zhao Liqiang Mai
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（7）
• 页码范围: 586-592
• 页数: 7页
• 语种: 英文

摘要

The selection of the most suitable crystal structure for ions storage and the investigation of the corresponding reaction mechanism is still an ongoing challenge for the development of Mg-based batteries.In this article,high flexible graphene network supporting different crystal structures of Nb2O5 (TT-Nb2O5@rGO and T-Nb2O5@rGO) are successfully synthesized by a spray-drying-assisted approach.The three-dimensional graphene framework provides high conductivity and avoids the aggregation of Nb2O5 nanoparticles.When employed as electrode materials for energy storage applications,TI-Nb2O5 delivers a higher discharge capacity of 129.5 rnAh g-1,about twice that of T-Nb2O5 for Mg-storage,whereas,T-Nb2O5 delivers a much higher capacity (162 mAh g-1) compared with TT-Nb2O5 (129 mAh g-1) for Li-storage.Detailed investigations reveal the Mg intercalation mechanism and lower Mg2+ migration barriers,faster Mg2+ diffusion kinetics of TT-Nb2O5 as cathode material for Mg-storage,and the faster Li+ diffusion kinetics,shorter diffusion distance of T-Nb2O5 as cathode material for Li-storage.Our work demonstrates that exploring the proper crystal structure of Nb2O5 for different ions storage is necessary.