Amine-Acrylate Michael Addition: A Versatile Platform for Fabrication of Polymer Electrolytes with Varied Cross-Linked Networks

Compared to the design of polymer electrolytes (PEs) using a strictly controlled copolymerization approach, the cross-linking polymerization method is more flexible and efficient and ensures the film-forming properties of the copolymer with strong mechanical strength. However, conventional cross-linked methods are difficult for structural modulation, thus limiting the further application of PEs in lithium metal batteries (LMBs). Herein, we report the amine-acrylate Michael addition for fabricating PEs with varied cross-linked networks. By adjustment of the molar ratios of the reacting monomers, PEs with different topologies were prepared. Notably, an excess of the amine monomer endowed the polymer electrolyte with a self-healing ability. In addition, the gel polymer electrolyte (GPE) was fabricated by the introduction of a deep eutectic solvent and showed a high ionic conductivity (1.44 × 10–4 S cm–1 at 30 °C), high oxidation voltage (>5.0 V vs Li+/Li), and excellent interface stability with the electrodes. The Li|GPE|Li cell can work for 1000 h at a current density of 0.1 mA cm–2. Moreover, Li|GPE|LiFePO4 cells could be cycled for 200 cycles at 0.5C with a capacity retention rate of 94.3%.