Tailorable pseudocapacitors for energy storage clothes

Abstract

Recently, flexible supercapacitors as promising energy storage devices for wearable electronics have drawn great attention. Here, all-solid-state tailorable supercapacitors (TSCs) based on flexible carbon nanotube (CNT)–polymer and CNT–metal oxide composite hybrid electrodes are successfully demonstrated. The CNT–polypyrrole (PPy) based TSC devices display an excellent electrochemical performance with a volumetric capacitive of 4.4 F cm⁻³ at the current density of 0.04 A cm⁻³ (energy density of 0.39 mW h cm⁻³ at a power density of 9.05 mW cm⁻³). Strikingly, the TSCs can maintain most of the electrochemical performance and still be operational for powering small electronics like a light-emitting diode (LED) even after undergoing a random cut. When the TSCs are cut down by half of their size, the capacitance retention was ∼50%, suggesting that the tailoring process can hardly affect their performance. Moreover, the other kind of TSC devices can be fabricated by using CNT–MnO₂ hybrid flexible electrodes as another example, which demonstrates the broadened potential of our design.