Constructing stable interfaces for wide-temperature and high-rate aqueous zinc metal batteries by dual-salt cosolvent electrolyte

Abstract

Rechargeable aqueous zinc metal batteries are large-scale new energy storage system due to their low cost and high safety. Nonetheless, a series of problems faced by zinc anode at wide temperatures will also limit its development, such as serious zinc dendrites and parasitic reactions. Herein, we report a dual-salt cosolvent electrolyte in which the addition of zinc perchlorate and 2-methyltetrahydrofuran assists the formation of stable SEI on the Zn anode surface. The ZnF2-rich SEI was constructed in-situ, which effectively inhibited the growth of zinc dendrite and exacerbation of parasitic reaction. Meanwhile, such solvents break the hydrogen bond network between the water molecules and change the solvation structure of Zn2+. Consequently, the Zn||Zn symmetric cells could remain stable during cycling for 9200 min at −20 °C and 6000 min at 60 °C (5 mA cm−2). Significantly, AZMBs exhibited an ultrahigh cumulative cycling capacity of 2250 mAh cm−2 at 20 °C. The PANI@V2O5 full cells maintained a capacity of 78.80 mAh/g after 250 cycles at −20 °C (2 A/g) and exhibited a long cycle life at 60 °C (more than 200 cycles). This study demonstrates a promising pathway for the future exploitation of high-rate AZMBs for operation under wide temperature.