A High-Performance Structural Supercapacitor

Abstract

Considering the low specific capacitance of structural solid supercapacitors, which is due to the low ion diffusivity in solid electrolytes and the small specific surface area of some structural electrodes such as carbon fiber fabrics, novel structural supercapacitor designs are proposed and evaluated in this study based on supercapacitor-functional sandwich composite materials. Typical electrochemical double layer capacitors (EDLCs) are proposed with liquid organic electrolyte 1 M TEABF4 in PC (propylene carbonate). In the innovative sandwich structured composites, supercapacitors are embedded in the skins and integrated in the honeycomb core where the aluminum faces of the core constitute the current collectors of the supercapacitor-functional core. The sandwich composite material exhibited a flexural modulus of 5.07 GPa and a flexural strength of 413.9 MPa. The EDLCs embedded in the skins increased the skin flexural modulus and strength by 47% and 56%, respectively, for embedded lateral EDLCs, and by 91% and 106%, respectively, for embedded lateral and longitudinal EDLCs. Compared to typical EDLCs with the same electrolyte, the structural supercapacitors in this study demonstrated superior specific electrode capacitance, C sp,el = 153 F g–1 for the honeycomb supercapacitor and C sp,el = 95.7 F g–1 for the skin supercapacitor, translating to overall structural composite material performance of 0.68 Wh/m2 honeycomb and 30.5 W/m2 honeycomb for the supercapacitor-functional honeycomb, and 0.02 Wh/m2 skin and 5.4 W/m2 skin for the supercapacitor-functional skin.

Design of Porous Carbons for Supercapacitor Applications for Different Organic Solvent-Electrolytes

“…The slower transport of PF 6 − in pores smaller than 1.8 nm corresponds to the limit of the tetrahedral solvated Li + ion [38], and seems to be linked to the ion exchange mechanism, where a lag is encountered for the PF 6 − concentration to rise at the start of charge. In the anode, the delay of the PF 6 − to return to 1 M in pores smaller than 1.2 nm at the end of discharge is due to the fact of insufficient electrochemical energy to overcome the desolvation energy barrier towards the end of discharge for PF 6 − to desolvate and return to the small pores. This creates a chain effect in delaying to empty the cathode macropore of 119 nm from PF 6 − ions, as well as delaying emptying the anode macropore of 119 nm of Li + ions.…”

“…Porous carbon is the main electrode material in the majority of symmetric electrochemical double-layer capacitors (EDLCs) [1], due to its good conductivity and ability to be activated into a large specific surface area. It is applied in different formats, including activated carbon fibers and activated carbon fabrics (ACFs) [2,3], activated carbon (AC) powder coatings [4][5][6], graphene [7][8][9][10][11], graphene oxide [11,12] and carbon nanotubes [13][14][15], where multiwall carbon nanotubes (MWCNT) also enhance electrode conductivity [5,16,17]. Composite electrodes consisting of a blend of these materials combine low resistance with high specific capacitance, resulting in supercapacitors of high power density and high energy density [5,[16][17][18].…”

Physicochemical Approaches for Thin Film Energy Storage Devices through PVD Techniques

“…Increasing energy consumption, rising human population and global warming has raised the necessity to progress alternative energy sources and Electrochemical Energy Storage (EES) devices for futuristic necessities. Further, intensifying demand on high-performance EES for portable microelectronic devices and hybrid electric vehicles has designed giant research thrust in the search for a novel diversity of energy storage devices [1][2][3]. Most of the modern microelectronic are intended to work on EES such as batteries, Supercapacitors and Hybrid Supercapacitors or Supercapbatteries.…”

Fabrication of Flexible Graphene Paper/MnO2 Composite Supercapacitor Electrode through Electrodeposition of MnO2 Nanoparticles on Graphene Paper

“…According to the energy storage mechanism, it can be divided into electrostatic double‐layer capacitor (EDLC) and electrochemical pseudocapacitor [7] . EDLC [8] stores charge through electrostatic interaction of ions at the electrolyte/electrode interface, which has low specific capacitance, but exhibits high stability and long life [9] . While, pseudocapacitors store charge through a fast and reversible oxidation‐reduction reaction, which shows a high specific capacitance, but has low stability and short cycle life [10–12] .…”