Polyphosphonitrile derivative-based gel electrolytes for all-climate zinc metal batteries operating from −70 °C to +80 °C

Abstract

The high freezing point and poor anode stability of traditional aqueous electrolytes strongly hamper the cyclability and working temperature range of zinc (Zn) metal batteries (ZMBs). Herein, we demonstrate a synergy of low-melting-point (LMP) co-solvents and in situ gelation treatment using a fireproof phosphonitrile derivative facilitating the all-climate operation of reliable ZMBs. As confirmed by theoretical modeling and experimental characterization, the low-temperature (LT) and high-temperature (HT) tolerances of batteries are realized by the anti-freezing LMP co-solvents and the thermo-stable solid electrolyte interphase (SEI) derived from the residual monomer, respectively. The resulting gel electrolytes not only eliminate safety concerns associated with fire hazards and liquid leakage, but also exhibit a high Zn plating/stripping efficiency of 99.75% over 6500 cycles with negligible water decomposition and dendrite formation. The as-developed ZMB full cells deliver an extended lifespan in an ultra-wide working temperature range (from −70 °C to +80 °C), thereby offering a new avenue for the development of all-climate ZMBs.