All-Transparent Stretchable Electrochromic Supercapacitor Wearable Patch Device

TLDR

Flexible and stretchable electrochromic supercapacitors are promising multifunctional energy storage devices, but their performance deteriorates when exposed to air and mechanical deformation. This study proposes an all‑transparent, stretchable electrochromic supercapacitor with ultrastable performance built from Au/Ag core‑shell nanowire‑embedded PDMS, bistacked WO₃ nanotube/PEDOT:PSS, and a PAAm‑based hydrogel electrolyte. The Au/Ag core‑shell nanowire‑embedded PDMS combined with the PAAm hydrogel prevents Ag oxidation and dehydration while preserving ionic and electrical conductivity under ambient exposure for 16 days and under tensile and bending strains, while the WO₃ nanotube/PEDOT:PSS bistacked active layer sustains high electrochemical‑electrochromic performance during deformation. The device delivers a maximum specific capacitance of 471 F g⁻¹ with 92.9 % capacity retention after 50 000 cycles and achieves a coloration efficiency of 83.9 cm² C⁻¹ owing to the dual coloration and pseudocapacitive behavior of the WO₃ nanotube and PEDOT:PSS layers.

Abstract

Flexible and stretchable electrochromic supercapacitor systems are widely considered as promising multifunctional energy storage devices that eliminate the need for an external power source. Nevertheless, the performance of conventional designs deteriorates significantly as a result of electrode/electrolyte exposure to atmosphere as well as mechanical deformations for the case of flexible systems. In this study, we suggest an all-transparent stretchable electrochromic supercapacitor device with ultrastable performance, which consists of Au/Ag core-shell nanowire-embedded polydimethylsiloxane (PDMS), bistacked WO3 nanotube/PEDOT:PSS, and polyacrylamide (PAAm)-based hydrogel electrolyte. Au/Ag core-shell nanowire-embedded PDMS integrated with PAAm-based hydrogel electrolyte prevents Ag oxidation and dehydration while maintaining ionic and electrical conductivity at high voltage even after 16 days of exposure to ambient conditions and under application of mechanical strains in both tensile and bending conditions. WO3 nanotube/PEDOT:PSS bistacked active materials maintain high electrochemical-electrochromic performance even under mechanical deformations. Maximum specific capacitance of 471.0 F g-1 was obtained with a 92.9% capacity retention even after 50 000 charge-discharge cycles. In addition, high coloration efficiency of 83.9 cm2 C-1 was shown to be due to the dual coloration and pseudocapacitor characteristics of the WO3 nanotube and PEDOT:PSS thin layer.