3D Wearable Fabric‐Based Micro‐Supercapacitors with Ultra‐High Areal Capacitance

Abstract

Miniaturized electronics require integrated unit configuration in very limited space, where energy storage per unit area is thus extremely critical. Micro-supercapacitors (MSCs), mainly established on planar substrates, are superior but still suffer from limited areal capacitance. Herein, a novel strategy is introduced to construct high cross-section MSCs using 3D fabrics as the porous skeleton. Interdigitated poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) is patterned on 3D fabrics to achieve continuous conductive networks, while MnO 2 microspheres epitaxially grown on PEDOT:PSS are fully exposed to electrolyte with the support of fabric fibers. The unique architecture can utilize more active sites of thick electrodes and the high conductivity of interpenetrating fiber networks. The resulting fabric-based MSCs demonstrate ultra-high areal capacitance of 135.4 mF cm −2 , which is 3.5 times that of devices on polyethylene terephthalate substrates and is among the highest values for planar-based MSCs using the same interdigital geometry. Moreover, the flexible fabrics endow MSCs with extremely high bending stability with 94% capacitance retention even after 3000 cycles. These figures-of-merit enable fabric-based MSCs promising to be used in the next-generation of wearable electronics.

Advances in the Robustness of Wearable Electronic Textiles: Strategies, Stability, Washability and Perspective

“…The device showed excellent durability, with no changes in the cyclic voltammetry (CV) curve before and after washing. Furthermore, the 3D fabric-based supercapacitor exhibited a remarkable areal capacitance (~135.4 mF cm −2 ) 3.5 times higher than that of the planar substrate (PET) based supercapacitor (Figure 5h) [187].…”

“…(h) (i) Fabrication of 3D fabric-based micro supercapacitor, (ii) capacitance retention of the device over 3000 bending cycles, (iii) cyclic voltammetry curve of the supercapacitor before and after washing. Reproduced with permission [187] Copyright 2021, Wiley. Tian et al reported a wearable piezoresistive sensor from polyester (PET)/polyethylene (PE) fiber-based 3D nonwoven fabric coated with multi-walled carbon nanotubes (MWCNT).…”

Constructing 3D Porous Current Collectors for Stable and Dendrite‐Free Lithium Metal Anodes

“…It is essential to develop new energy technologies such as lithium (Li)-ion batteries (LIBs), supercapacitors, or solar cells with efficient energy storage and conversion ability to deal with the energy and environmental crisis. [1][2][3][4][5] However, as the traditional graphite anode Large specific surface area because of high structure porosity can reduce the local effective current density. Therefore, the use of 3D current collectors mainly prolongs the Sand's time and slows down the formation of Li dendrites by reducing the local effective current density.…”

“…It is essential to develop new energy technologies such as lithium (Li)‐ion batteries (LIBs), supercapacitors, or solar cells with efficient energy storage and conversion ability to deal with the energy and environmental crisis. [ 1–5 ] However, as the traditional graphite anode in LIBs, the low theoretical capacity can no longer meet the requirement of high‐density energy supply. [ 6–11 ] Therefore, it is of great significance to seek alternative Li anode materials to improve its specific capacity.…”

A durable high-energy implantable energy storage system with binder-free electrodes useable in body fluids

“…Therefore, studies are needed to develop energy storage devices with a long lifespan, miniaturization, and flexibility. 9,10 Furthermore, implantable secondary energy storage devices that are safe for living cells but that do not interfere with biological functions can be used. 11…”