A High-Performance Quasi-Solid-State Aqueous Zinc–Dual Halogen Battery
Shuyao Lv, Timing Fang, Zhezheng Ding, Yan Wang, Hao Jiang, Chuanlong Wei, Dong Zhou, Xiao Tang, Xiaomin Liu
Abstract
Aqueous zinc-based batteries are promising candidates for the grid-scale energy storage owing to their nonflammability, ecofriendliness, and low cost. Nevertheless, their practical applications are hindered by the relatively low capacity and energy density. Herein, we develop a quasi-solid-state aqueous zinc–dual halogen battery composed of freestanding carbon cloth–iodine cathode and in situ prepared concentrated aqueous gel electrolyte. The freestanding composite cathode and aqueous gel electrolyte can afford iodine source and bromide ions, respectively, thus activating the I–/I0/I+ reaction by forming [IBr2]− interhalogen. Furthermore, the conversion reaction of Br–/Br0 in [IBr2]− interhalogen is stimulated due to the catalytic effect of iodine. Therefore, this rationally designed aqueous dual halogen conversion chemistry enables three successive redox reactions (i.e., I–/I0, I0/I+, and Br–/Br0). Additionally, the LiNO3 additive and acrylamide (AM)-based polymer matrix not only stabilizes the anode/electrolyte interface but also restrains the side reactions and dissolution/diffusion of active species. Consequently, the as-assembled aqueous zinc–dual halogen battery exhibits high areal capacity and energy density.