Based Self-Healing Polymer Electrolyte For Safe And Long-Life Lithium-Metal Batteries

The development of high-density lithium metal batteries is limited by the growth of lithium dendrites and the safety hazards of flammable liquid electrolytes. Improving eutectic solvent electrolytes and improving their compatibility with lithium metal are effective ways to promote the development of high-density lithium metal batteries. Recent research results published in "Angewandte Chemie" show that scientists have developed a eutectic solvent-based polymer electrolyte (DSP) with excellent flame retardant and self-healing properties to help stabilize a stable quasi-solid lithium metal battery.

This electrolyte was fabricated in a facile manner by in situ copolymerization of 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl methacrylate (UPyMA) and pentaerythritol tetraacrylate (PETEA) monomers in a DES‐based electrolyte containing fluoroethylene carbonate (FEC) as an additive.

The well-designed DSP electrolyte has non-combustibility, high ionic conductivity and excellent electrochemical stability as well as dendrite-free Li plating. The ion conductivity at 25 ℃ can reach 1.79 × 10-3S cm-1, which can induce the formation of a dense and thin SEI film and the positive electrode electrolyte interface (CEI) film at the electrolyte-electrode interface. In addition, the electrolyte can inhibit the growth of lithium dendrites and the dissolution of Mn²⁺ in the cathode under high temperature conditions, which can broaden the operating temperature range of the battery and significantly improve the safety and cycle stability of the lithium metal battery.

This electrolyte can effectively inhibit the dissolution of manganese from the cathode of lithium metal battery with LiMn₂O₄ cathode, and has high capacity and long life at room temperature and high temperature. Its battery cycle performance is better than that of the previously reported eutectic solvent-based lithium-ion battery system, which is conducive to its practical application in low-cost energy storage.

References: Pauline Jaumaux, Qi Liu, Dong Zhou *, Xiaofu Xu, Tianyi Wang, etal. Deep Eutectic Solvent-Based Self-Healing Polymer Electrolyte for Safe and Long-Life Lithium Metal Batteries.Angew. Chem. Int. Ed., 2020, DOI: 10.1002 / anie.202001793