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

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.