13. Shape Memory Supercapacitors

Nowadays, the increasing demand for energy storage devices and high-power density compared to batteries makes promising supercapacitor candidates for commercial application. Shape memory properties are seamlessly integrated with the supercapacitor to fulfill the stable energy requirement of flexible devices. Considerable research gained attention to developing shape memory supercapacitors in electrochemical energy devices. Different shape memory materials have been used to assemble the device and study the electrochemical performance, cyclic stability, etc. We have reviewed and explained shape memory materials types, such as shape memory alloy (SMA) and shape memory polymer (SMP). Both types of material have unique intrinsic shape memory properties such as strain recovery (R_r), shape fixity (R_f), and recovery time. Mainly heat-triggered shape memory material is used in the application, and its transition temperature largely depends on the material and material composition. The flexibility of the shape memory device depends on the design, architecture, materials, etc.; wire-shaped and planar devices have been studied extensively. Symmetric and asymmetric shape memory supercapacitors have been reviewed. Apart from this principle behind shape memory properties, the design aspect and electrochemical performance of recent advancements in SMSC have been reported.