Stimulus-responsive polymers for safe batteries and smart electronics

Stimulus-responsive energy storage devices, which can respond to external stimuli, such as heat, pH, moisture, pressure, or electric field, have recently attracted intensive attention, aiming at the ever-increasing demand for safe batteries and smart electronics. The most typical stimulus-responsive materials are polymers that can change their conformation by forming and destroying secondary forces, including hydrogen bonds and electrostatic interactions in response to external stimuli, accompanied by changes in the intrinsic properties such as conductivity and hydrophobicity. Although the applications of stimulus-responsive functions in rechargeable batteries are still in the early stage because of the complexity and compatibility of battery architectures, many new concepts of regulating the polymer structures upon applications of stimuli have already been developed. In this review, we discuss the recent progress of stimulus-responsive polymers on energy storage devices featuring thermal protection and intelligent scenarios, with a focus on the detailed structural transformations of polymers under a given stimulus and the corresponding changes in battery performance. Finally, we present perspectives on the current limitations and future research directions of stimulus-responsive polymers for energy storage devices.