Structural pseudocapacitors with reinforced interfaces to increase multifunctional efficiency

Abstract

Structural supercapacitors hold promise to expand the energy capacity of a system by integrating load-bearing and energy-storage functions in a multifunctional structure, resulting in weight savings and safety improvements. Here, we develop strategies based on interfacial engineering to advance multifunctional efficiency. The structural electrodes were reinforced by coating carbon-fiber weaves with a uniquely stable conjugated redox polymer and reduced graphene oxide that raised pseudocapacitive capacitance and tensile strength. The solid polymer electrolyte was tuned to a gradient configuration, where it facilitated high ionic conductivity at the electrode-electrolyte interfaces and transitioned to a composition with high mechanical strength in the bulk for load support. The gradient design enabled the multilayer structural supercapacitors to reach state-of-the-art performance matching the level of monofunctional supercapacitors. In situ electrochemical-mechanical measurements established the device durability under mechanical loads. The structural supercapacitor was made into the hull of a model boat to demonstrate its multifunctionality.

Multifunctionality Analysis of Structural Supercapacitors— A Review

“…The first carbon fiber (CF)-based structural capacitor was built in 2001 [9]; however, the term "SSCs" was first introduced by the United States Army in 2008 [10], but similar ideas on multifunctional materials have been circulated since at least 2003, as investigated by Christodoulou and Venables [11]. Currently, initial concept studies have been demonstrated for fuselage beams [12], satellite panels [13], and composite boat hulls [14] (Figure 1b-d). One of the first studies on the mechanical and electrical behavior of CF structural capacitors including the effects of delamination and interlaminar damage was conducted by Shen and Hongyu in 2017 [15] and prediction of the mechanical behavior of SSCs was carried out by Valkova et al in 2022 [16].…”

“…One of the first studies on the mechanical and electrical behavior of CF structural capacitors including the effects of delamination and interlaminar damage was conducted by Shen and Hongyu in 2017 [15] and prediction of the mechanical behavior of SSCs was carried out by Valkova et al in 2022 [16]. [12], (c) multifunctional highly integrated satellite panel powered by structural supercapacitors [13], (d) boat hull with integrated structural supercapacitors [14].…”

“…Figure 1. (a) Schematic of multifunctionality as a combination of high mechanical and high electrochemical properties, (b) structural supercapacitor constituents inside a multifunctional fuselage beam demonstrator[12], (c) multifunctional highly integrated satellite panel powered by structural supercapacitors[13], (d) boat hull with integrated structural supercapacitors[14].…”