Zinc niobate materials: crystal structures, energy-storage capabilities and working mechanisms. Issue 44 (31st October 2019)

• Record Type: Journal Article
• Authors: Zhu, Xiangzhen; Cao, Haijie; Li, Renjie; Fu, Qingfeng; Liang, Guisheng; Chen, Yongjun; Luo, Lijie; Lin, Chunfu; Zhao, Xiu Song
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 44(2019)
• Page Start: 25537
• Page End: 25547
• Publication Date: 2019-10-31
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9ta07818e
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Two tungsten-free and niobium-rich Zn2 Nb34 O87 materials with excellent electrochemical reversibility are explored as better anode materials than the famous W5 Nb16 O55 . Abstract : W5 Nb16 O55 is a very promising negative electrode compound for lithium-ion storage owing to its good safety, durable cyclability and high rate performance. However, its commercialization is hindered by its limited capacity and high tungsten cost. Here, we designed a tungsten-free and niobium-rich zinc niobate (Zn2 Nb34 O87 ) with a large capacity (theoretically 389 mA h g −1 ) as a new insertion negative electrode compound. Micron-sized Zn2 Nb34 O87 blocks (Zn2 Nb34 O87 -B) and one-dimensional Zn2 Nb34 O87 nanofibers (Zn2 Nb34 O87 -N) were prepared via a solid-state reaction and electrospinning methods, respectively. Zn2 Nb34 O87 -B and Zn2 Nb34 O87 -N have 3 × 4 × ∞ shear ReO3 crystal structures of orthorhombic and monoclinic types, respectively. Both the Zn2 Nb34 O87 materials exhibited better electrochemical performance than W5 Nb16 O55 in terms of the capacity, lithium-ion diffusion coefficient, intercalation pseudocapacitive contribution, rate performance, and cyclability. In situ X-ray diffraction characterization demonstrated the excellent structural stability and electrochemical reversibility of Zn2 Nb34 O87, and revealed that lithium ions were stored in the (010) crystallographic planes. Furthermore, a LiNi0.5 Mn1.5 O4 ‖Zn2 Nb34 O87 -N full cell exhibited outstanding electrochemical performance, including a large capacity, prominent rate performance, and especially ultra-long cyclability (96.5% capacity retention even after 1000 cycles at 5C). Therefore, Zn2 Nb34 O87 holds great promise as a practical negative electrode compound for large-capacity, cost-effective, rapid, durable and safe lithium-ion storage.