Electrolyte for Zn metal battery under extreme temperature operations design by Lewis acid-base chemically mediated polymerization of cyclic ether

Abstract

The high interfacial stability, low metal corrosion, excellent dendrite inhibition, and good ionic conductivity are crucial for the electrolyte employed in extreme temperature operations of zinc ion batteries. However, these properties are seldom achieved simultaneously, particularly at low temperatures. In this study, we report a novel weakly solvated electrolyte that is controllably synthesized through Lewis acid-base chemical mediation of the polymerized 1,3-dioxolane (pDOL) chain length. This results in a wide electrochemical window (2.87 V vs. Zn/Zn²⁺), a rapid Zn²⁺ de-solvation process and appropriate ionic conductivity in a wide temperature range (–70 ∼ +25 °C) at low salt concentration. The long-chain pDOL solvent endows the electrolyte with excellent dendrite inhibition (5400 h at 25 °C, 1086 h at –20 °C, and 1024 h at –40 °C), and also addresses the issue of undesired self-corrosion. The differential behavior of the Zn plating/stripping process and interfacial chemistry in this novel electrolyte at various temperatures was analyzed using multiple characterization techniques. Notably, the Zn//PANI full cells exhibit enhanced electrochemical properties, including a high capacity retention ratio and excellent cycling stability under extreme temperature operations from –70 to +25 °C. This work demonstrates a promising approach for the design of electrolytes tailored for extreme operating conditions.