Paper-Derived Millimeter-Thick Yarn Supercapacitors Enabling High Volumetric Energy Density

Abstract

Solid-state supercapacitors have shown extraordinary promise for flexible and wearable electronics. To date, they are still limited by relatively poor energy volumetric performances, which are largely determined by the pore structures and physicochemical properties of electrode materials. Moreover, the poor mechanical properties afforded because of the intrinsic shortcomings of electrode materials need to be resolved. Herein, we designed a flexible and solid-state yarn electrode with high porosity and high affinity toward electrolytes using poly­(3,4-ethylenedioxythiophene) (PEDOT) and Korean heritage paper (KHP). To maximize the volumetric capacitive energy storage, PEDOT-loaded conductive KHP sheets (two-dimensional) were transformed into a biscrolled yarn (one-dimensional) via simple twisting. The volumetric capacitance of the biscrolled yarn supercapacitors with 1 mm cell diameter exhibited a volumetric specific capacitance of ∼6576 mF/cm3 at a scan rate of 25 mV/s, which is attributable to the high mass loading of PEDOT as a conductive support and increased packing density. Moreover, multiple optimized yarn supercapacitors can be connected to yield a total length of 1 m, demonstrating enormous potential as a portable and wearable power supply for operating smartwatches.

A multifunctional paper-based supercapacitor with excellent temperature adaptability, plasticity, tensile strength, self-healing, and high thermoelectric effects

“…This is because the rise in temperature accelerates the ow of electrolyte ions in the APC-PVA@ZnCl 2 supercapacitor, which enables more electrolyte ions to reach the interior of the electrode material bulk phase, thus effectively improving the specic capacitance of the supercapacitor. On the whole, these volumetric specic capacitance values can be compared to some previous literature works, [34][35][36][37] as displayed in Fig. 4c.…”

“…4c and d) displays comparison maps of volumetric specic capacitance and energy density of APC-PVA@ZnCl 2 with reported works. [34][35][36][37][38][39][40][41][42] It is obvious that our work can be compared with those excellent works in recent years. All in all, these results demonstrate that the APC-PVA@ZnCl 2 supercapacitor has excellent environmental adaptability, showing its potential application value in different environments.…”

Recent research progress of paper-based supercapacitors based on cellulose

“…The results show that the electrode (PEDOT/CP-10) after 10 polymerization shows excellent conductivity (14 Ω/square) and a volume ratio capacitance of 13.7F cm -3 . Similarly, Heo et al [100] obtained conductive KHO (C-KHP) by loading Korean conventional paper (KHP) with a loaded conductive ink. Then the PEODT is loaded on C-KHP by gas phase polymerization to obtain PC-KHP paper-based composite electrode material.…”

Recent Advanced Supercapacitor: A Review of Storage Mechanisms, Electrode Materials, Modification, and Perspectives

“…Supercapacitors are being researched extensively in smart electronics applications such as flexible, biodegradable, transparent, wearable, flexible, on-chip, and portable energy storage. In comparison with conventional capacitors, supercapacitors use materials with a high specific surface area as electrodes [ 8 , 9 ]. A higher specific surface area and thinner dielectrics result in greater specific capacitance and energy density.…”

“…Supercapacitors have many other advantages, such as being environmentally friendly, having a long service life, being able to operate in wide temperature ranges, and being good at retaining charge even when large currents are applied; they are widely used in consumer electronics, smart meters, and transport [ 7 , 8 , 9 , 10 ]. Supercapacitors have shown that they can perform very well in some applications, but there are still several shortcomings that are relevant in some applications.…”