High-energy-density aqueous zinc-based hybrid supercapacitor-battery with uniform zinc deposition achieved by multifunctional decoupled additive. (1st June 2022)

• Record Type: Journal Article
• Authors: Wang, Shengnan; Li, Tianyu; Yin, Yanbin; Chang, Nana; Zhang, Huamin; Li, Xianfeng
• Is Part Of: Nano energy. Volume 96(2022)
• Publication Date: 2022-06-01
• Subjects: Supercapacitor-battery -- Additive -- Zinc deposition; 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.2022.107120
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Aqueous Zn-based hybrid supercapacitors (ZHSs) are promising energy storage devices, benefiting from their safety, high power density, low-cost and environmental benignity. However, the major issues of Zn dendrites and low energy density severely hinder their further rapid development. Herein, a multifunctional decoupled additive, 1-methyl-1-ethyl pyrrolidinium bromide (MEP∙Br), is proposed to update the traditional ZHS to Zn-based hybrid supercapacitor-battery (ZHSB) with higher energy density. Thanks to the merits of the uniform Zn deposition induced by MEP +, reduced polarization derived from alteration of solvation structure by Br −, increased capacity from rapid electrochemical reversible reaction of Br2 /Br −, and the fixation of charged Br2 -containing species in cathode realized by robust complexation of MEP∙Br, compared with the traditional ZHS, the ZHSB with MEP∙Br demonstrates a much higher average energy density of 383.2 W h kg −1 (265.8 mAh g −1 ) and long-term cycling durability (over 5000 cycles) at a high power density of 16.8 kW kg −1 (10 A g −1 ). Interestingly, even at an ultrahigh current density of 20 A g −1, the ZHSB can still deliver a high specific capacity of 252.4 mAh g −1 (about three times higher than that of ZHS). This work provides a new option for the next generation energy storage technologies. Graphical Abstract: ga1 A multifunctional decoupled additive (MEP∙Br) is proposed to realize a novel Zn-based hybrid supercapacitor-battery (ZHSB) with high energy and power density. Benefiting from the role of MEP∙Br in flattening Zn deposition, reducing battery polarization and introducing the redox couple of Br2 /Br −, ZHSBs demonstrate a high average energy density of 383.2 W h kg −1 (16.8 kW kg −1 ) over 5000 stable cycles. Highlights: The decoupled additive can flatten Zn deposition and reduce polarization. The additive introduces the redox couple of Br2 /Br − to improve the capacity of cathode. The Zn-based hybrid supercapacitor-battery can demonstrate a high average energy density of 265.8 mAh g −1 at 10 A g −1 .