Designing a Novel Polymer Electrolyte for Improving the Electrode/Electrolyte Interface in Flexible All-Solid-State Electrical Double-Layer Capacitors

Abstract

A novel copolymer, polyurethane-poly(acrylic acid) (PAA), is successfully synthesized from poly(acrylic acid) (PAA) backbone cross-linked with waterborne polyurethane (WPU). This sticky polymer, which is neutralized with 1 M KOH and then soaked in 1 M KOH (denoted as WPU-PAAK-K), provides an ionic conductivity greater than 10 S cm and acts as a gel electrolyte perfectly improving the electrode/electrolyte interfaces in a flexible all-solid-state electrical double-layer capacitor (EDLC). The PAA backbone chains in the copolymer increase the amount of carboxyl groups and promote the segmental motion. The carboxyl groups enhance the water-uptake capacity, which facilitates the ion transport and promotes the ionic conductivity. The cross-linked agent, WPU chains, effectively maintains the rich water content and provides mechanical stickiness to bind two electrodes together. An acid-treated carbon paper (denoted as ACP) combining with such a gel polymer electrolyte demonstrates excellent capacitive behavior with a high areal capacitance of 211.6 mF cm at 10 mV s. A full cell consisting of ACP/WPU-PAAK-K/ACP displays a low equivalent series resistance of 0.44 Ω from the electrochemical impedance spectroscopic results. An all-solid-state ACP/WPU-PAAK-K/ACP EDLC provides an areal specific capacitance of 94.6 mF cm at 1 mA cm. This device under 180° bending shows a capacitance retention over 90%, revealing its remarkable flexibility.

Na2SO4‐Polyacrylamide Electrolytes and Enabled Solid‐State Electrochemical Capacitors

“…Solid cells with YP‐50 AC electrodes were constructed using Na 2 SO 4 −PAM(10,000 : 1) electrolyte, and their performance were compared to the liquid baseline cells with aqueous 0.5 M Na 2 SO 4 electrolyte. In polymer electrolytes enabled solid devices, maintaining excellent electrolyte/electrode interface is crucial for good performance . In this study, intimate contact between polymer electrolyte and AC electrodes was achieved by directly casting electrolyte precursor solution on the electrodes during the cell construction.…”

Structural, Impedance and Electrochemical Characteristics of Electrical Double Layer Capacitor Devices Based on Chitosan: Dextran Biopolymer Blend Electrolytes

“…This constant current for a period of time is known as steady-state current where there is a polarization of the electrodes [70]. To take advantage of this state, calculation of t ion and t el values is easy to perform using the aforementioned Equations (1) and (2). The values of t ion and t el are thus found to be 0.928 and 0.072, respectively.…”

“…Vijaya et al stated that as a benchmark, the ideal value of transference number for an electrolyte is in the range of 0.90 to 0.99, for example, for ammonium salt-based polymer electrolyte [71]. advantage of this state, calculation oftion and tel values is easy to perform using the aforementioned Equations (1) and (2). The values of tion and tel are thus found to be 0.928 and 0.072, respectively.…”

“…The heart of technology devices is the energy generator part; electrochemical double-layer capacitors (EDLCs) can be regarded as potential energy sources in many electronic devices. The superiority of EDLCs can be associated with a relatively long life-cycle, ease of fabrication, safety, and high performance [ 1 , 2 ]. Carbon materials have been used as the backbone materials in EDLC electrodes, activated carbon being the most popular one.…”

Electrochemical Characteristics of Glycerolized PEO-Based Polymer Electrolytes

“…Lately, electric double-layer capacitors (EDLCs)have attracted more attention due to having unique characteristics, such as higher energy density, durability, reversibility, quick charge-discharge rate, and improved safety, which makes them striking for a broad range of applications [10]. As a complementary technology device, EDLCs can be deliberated as a potential alternative to conventional lithium batteries [11][12][13][14]. In this type of electrochemical capacitor, the mechanism of energy storage is based on the accumulation of charge at the surface of a carbon electrode that converts into potential energy [15][16][17].…”