A zinc battery with ultra-flat discharge plateau through phase transition mechanism. (May 2020)

• Record Type: Journal Article
• Authors: Wang, Donghong; Zhao, Yuwei; Liang, Guojin; Mo, Funian; Li, Hongfei; Huang, Zhaodong; Li, Xinliang; Tang, Tiancheng; Dong, Binbin; Zhi, Chunyi
• Is Part Of: Nano energy. Volume 71(2020)
• Publication Date: 2020-05
• Subjects: Ultra-flat -- Discharge plateau -- Single-phase transition -- High rate; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2020.104583
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Rechargeable aqueous zinc batteries have attracted enormous attention due to the distinctively economic and environmental advantages. However, the present zinc batteries delivered sloping voltage profiles based on the dominant mechanism of Zn ion intercalation. Typically, a Zn–V2 O5 battery exhibits a discharge slope of ~4.3 V/(Ah g −1 ) and a slope of ~1.5 V/(Ah g −1 ) is observed for MnO2 cathodes. Furthermore, the rate capacity based on intercalation is limited. Here we report a highly flat voltage profile for a reversible alkaline zinc battery with α-Bi2 O3 as the cathode. Different from the conventional zinc batteries, zinc-α-Bi2 O3 batteries possess a first-order phase transition process that is the responsible cause of their outstanding performance, such as an ultra-flat output voltage [slope: ~0.1 V/(Ah g −1 )], a high discharge capacity of 323 mAh g −1 at 0.1 A g −1 and excellent rate capacity with a 155 mAh g −1 capacity even at 20A g −1 (61C). In addition, a high areal energy density of 1.5 mWh cm −2 is achieved at power density of 4.4 mW cm −2 . Moreover, the quasi-solid-state Zn-α-Bi2 O3 battery is also fabricated using a sodium polyacrylate (PANa) as the hydrogel electrolyte, exhibiting promising application as power source for flexible devices. Graphical abstract: Rechargeable alkaline Zn-α-Bi2 O3 battery delivered narrow redox peaks, ultra-flat discharge plateau and decent rate capability, based on a single-phase transition mechanism between α-Bi2 O3 and Bi. Image 1 Highlights: Reversible alkaline Zn//α-Bi2 O3 battery. Long ultra-flat discharge plateau. Single-phase transition between α-Bi2 O3 and Bi.