Configuration-dependent stretchable all-solid-state supercapacitors and hybrid supercapacitors

Given the rise in the popularity of wearable electronics that are able to deform into desirable configurations while maintaining electrochemical functionality, stretchable and flexible (hybrid) supercapacitors (SCs) have become increasingly of interest as innovative energy storage devices. Their outstanding power density, long lifetime with low capacitance loss, and appropriate energy density, in particular in hybrid cases make them ideal candidates for flexible electronics. The aim of this review paper is to provide an in-depth discussion of these stretchable and flexible SCs ranging from fabrication to electro-mechanical properties. This review paper begins with a short overview of the fundamentals of charge storage mechanisms and different types of multivalent metal-ion hybrid SCs. The research methods leading up to the current state of these stretchable and flexible SCs are then presented. This is followed by an in-depth presentation of the challenges associated with the fabrication methods for different configurations. Proposed novel strategies to maximize the elastic and electrochemical properties of stretchable/flexible or quasi-solid-state SCs are classified and the pros and cons associated with each are shown. The advances in mechanical properties and the expected advancements for the future of these SCs are discussed in the last section.