Ivy-Inspired Design of Polymer Gel Electrolytes for Fiber Lithium-Ion Batteries with High Stability

Abstract

Polymer gel electrolytes have been integrated into flexible electrodes with channeled structures to replace liquid electrolytes, enabling flexible lithium-ion batteries that offer both enhanced safety and high performance. However, conventional gel electrolyte preparation often requires harsh conditions-such as heating, ultraviolet (UV) irradiation, or oxygen-free environments- which hinder scalable and cost-effective manufacturing. Inspired by the natural adhesion mechanism of ivy, which winds around supports, secretes a monomer-rich fluid, and undergoes mild crosslinking, a fiber lithium-ion battery is designed by co-winding fiber-based cathodes and anodes, followed by infiltrating and curing a precursor solution containing ternary and pentagonal cyclic ethers as monomers and a Lewis acid as an electrophilic initiator. This solution undergoes room-temperature curing, forming a robust and stable interface between the gel electrolyte and electrodes. The resulting fiber battery exhibits excellent cycling stability (88% capacity retention after 1000 cycles), mechanical durability (96% retention after 10 000 bending cycles), and storage stability (80% capacity retention at 40 °C and 80% relative humidity (RH)). Remarkably, the battery remains operational under extreme conditions such as cutting and burning. This bioinspired strategy eliminates complex processing steps and lowers production costs by 46%, achieving a manufacturing cost of $1.5 per meter-a critical advancement for the scalable application of flexible battery technology.

Keywords: fiber lithium‐ion batteries; in situ polymerization; low‐cost; polymer gel electrolyte; room temperature.