Recent progress in gel polymer electrolyte for lithium metal batteries

Lithium metal batteries (LMBs) with high energy density have been deemed as one of the promising alternatives to alleviate the “range anxiety” of current electric vehicles based on traditional lithium-ion batteries. However, LMBs using traditional liquid electrolytes (LEs) are always facing serious lithium dendrite growth and electrolyte leakage issues, which could usually cause serious safety concerns. Solid polymer electrolytes (SPEs) with high mechanical stability could suppress the lithium dendrites to some extent, however, they are suffering from low ionic conductivity and inferior interfacial contact with electrodes. Gel polymer electrolytes (GPEs) combining the advantages of traditional LEs and SPEs could be a promising choice to alleviate above issues. In this review, we systematically summarized and clarified very recent progress of various advanced GPEs for LMBs, which is mainly focusing on the advancement of different polymer matrices used for GPE-based LMBs as well as the development of methodologies for the preparation of GPEs. In addition, we also provide a perspective aiming at inspiring new ideas and directions to design reliable GPEs for advancing the performance of LMBs and boosting their practical application.