Highly stretchable multifunctional polymer ionic conductor with high conductivity based on organic-inorganic dual networks

Abstract

Ionogels based on ionic liquids have attracted great attention in the field of energy storage and sensing due to their intrinsic advantages, including good thermal stability, low flammability and volatility, and favorable electrochemical properties. However, the introduction of ionic liquids usually sacrifices the mechanical properties of ionogels, such as stretchability and strength. Herein, inspired by reinforced concrete structures, an ionogel with rigid inorganic and flexible organic interpenetrating dual network is created, which exhibits high mechanical strength, excellent elongation (nearly 900%), good elasticity and high room temperature ionic conductivity (1.34 mS cm−1) by exploring the synergistic effect between the rigid and flexible components. Such a highly stretchable conductive organic–inorganic dual network is constructed through non-hydrolyzed sol–gel reaction of tetrabutyl titanate and in situ polymerization of butyl acrylate through UV irradiation. Impressively, the assembled energy stroage device (lithium-ion batteries) based on the ionogel exhibits over 1000 stable cycles with average Columbic efficiency of ∼ 100%, and excellent rate property. The resulting stretchable lithium-ion battery can power an LED at 50% strain. The ionogel, as ionic skin, also shows highly repeatable electrical responses in reciprocal deformation cycles. In terms of the above unusual features, the as-perpared ionogel manifests great promise for versatile applications in the field of flexible electronics.