Nano-zirconia boosting the ionic conductivity and lithium dendrite inhibition ability of a poly(1,3-dioxolane) solid electrolyte for high-voltage solid-state lithium batteries

Abstract

A high ionic conductivity, excellent mechanical and strong inhibition ability of lithium dendrites are necessary for polymer solid electrolytes. In this work, a poly(1,3-dioxolane)/yttria-stabilized zirconia (PDOL–YSZ) composite solid electrolyte membrane (CSEM) was prepared for the first time by using lithium hexafluorophosphate (LiPF₆) to initiate 1,3-dioxolane (DOL) polymerization. YSZ nanoparticles promote the polymerization process of DOL and more free Li⁺ ions are released through its reaction with the anions of the lithium salt, resulting in a high ionic conductivity of 5.82 × 10⁻⁴ S cm⁻¹ and a wide electrochemical stability window of 5.1 V. Besides, YSZ can react with the lithium anode to form a stable solid electrolyte interface (SEI) including a Li₂ZrO₃ fast ionic conductor, which is beneficial to the interface stability between the lithium anode and the CSEM, inhibiting the growth of lithium dendrites during battery cycling, and the Li/CSEM/Li cells can be cycled stably for nearly 1500 hours at a current density of 0.1, 0.3 and 0.5 mA cm⁻². The assembled LiCoO₂/CSEM/Li cells can be cycled for 200 cycles at 0.5C with a capacity retention of 90%. This PDOL–YSZ CSEM shows high promising commercial application prospects due to its easy preparation, high ionic conductivity and excellent inhibition ability of lithium dendrites.