Gel polymer electrolyte for flexible and stretchable lithium metal battery: Advances and prospects

Flexible and stretchable energy storage devices are highly desirable for wearable electronics, particularly in the emerging fields of smart clothes, medical instruments, and stretchable skin. Lithium metal batteries (LMBs) with high power density and long cycle life are one of the ideal power sources for flexible and stretchable energy storage devices. However, the current LMBs are usually too rigid and bulky to meet the requirements of these devices. The electrolyte is the critical component that determines the energy density and security of flexible and stretchable LMBs. Among various electrolytes, gel polymer electrolytes (GPEs) perform excellent flexibility, safety, and high ionic conductivity compared with traditional liquid electrolytes and solid electrolytes, fulfilling the next generation deformable LMBs. This essay mainly reviews and highlights the recent progress in GPEs for flexible/stretchable LMBs and provides some useful insights for people interested in this field. Additionally, the multifunctional GPEs with self-healing, flame retardant, and temperature tolerance abilities are summarized. Finally, the perspectives and opportunities for flexible and stretchable GPEs are discussed.