Recycling of typical supercapacitor materials

Abstract

Abstract:A simple, facile and low cost method for recycling of supercapacitor materials is followed. This process aims to recover some fundamental components of a used supercapacitor namely the electrolyte salt TEABF4 (tetraethyl ammonium tetrafluoroborate) dissolved in an aprotic organic solvent such as ACN (acetonitrile), the carbonaceous material (activated charcoal, CNTs) purified, the current collector (aluminum foil) and the separator (paper) for further utilization. The method includes mechanical shredding of the supercapacitor in order to reduce its size and separation of aluminum foil and paper from the carbonaceous resources containing TEABF4 by sieving. The extraction of TEABF4 from the carbonaceous material was based on its solubility in water and subsequent separation through filtering and distillation. Cyclic voltammetry curve of the recycled carbonaceous material revealed supercapacitor behavior allowing a potential reutilization. Furthermore, since BF4-stemming from TEABF4 can be slowly hydrolyzed in aqueous environment releasing thus F-anions which are hazardous we went on to their gradual trapping with calcium acetate and conversion to non hazardous CaF2. AbstractA simple, facile and low cost method for recycling of supercapacitor materials is followed. This process aims to recover some fundamental components of a used supercapacitor namely the electrolyte salt TEABF 4 (tetraethyl ammonium tetrafluoroborate) dissolved in an aprotic organic solvent such as ACN (acetonitrile), the carbonaceous material (activated charcoal, CNTs) purified, the current collector (aluminum foil) and the separator (paper) for further utilization. The method includes mechanical shredding of the supercapacitor in order to reduce its size and separation of aluminum foil and paper from the carbonaceous resources containing TEABF 4 by sieving. The extraction of TEABF 4 from the carbonaceous material was based on its solubility in water and subsequent separation through filtering and distillation. Cyclic voltammetry curve of the recycled carbonaceous material revealed supercapacitor behavior allowing a potential reutilization. Furthermore, since BF 4 -stemming from TEABF 4 can be slowly hydrolyzed in aqueous environment releasing thus F -anions which are hazardous we went on to their gradual trapping with calcium acetate and conversion to non hazardous CaF 2 .

Supercapacitors in the Light of Solid Waste and Energy Management: A Review

“…In addition to that, to check the hazardous release of F − ions due to BF 4 − stemming from TEABF 4 and hydrolysis in an aqueous environment, the ions were trapped with calcium acetate and converted to nonhazardous CaF 2 . [122] Wu et al successfully recovered activated carbon from a used HYPSC-002R7-3000 supercapacitor and utilized it as a low-cost adsorbent to remove toxic Ag(I) and Cr(VI) ions from aqueous solutions effectively. The electrodes, consisting of activated carbon powder, organic binder, and aluminous current collector, were obtained from the supercapacitor after a discharging pretreatment.…”

“…Although recycling electrochemical devices is a common practice in many countries, supercapacitors are yet to gain attention in this regard. Nevertheless, a few noteworthy recycling strategies to recover and reuse supercapacitor components [ 120–123 ] as well as develop recyclable supercapacitors [ 124,125 ] have been reported. To avoid risks of exposing harmful components of a supercapacitor to the environment after its end of life, research on the development of binder‐less supercapacitors is also being carried out.…”

Electrochemical double-layer capacitors with lithium-ion electrolyte and electrode coatings with PEDOT:PSS binder

“…Amongst several conducting polymers offering pseudocapacitance, PEDOT:PSS has been the focus of more research studies because of its high conductivity that reduces the equivalent in series resistance (ESR) of the EDLC [23] and also facilitates the redox kinetics for pseudocapacitance. A PEDOT:PSS binder disintegrates in a water stream and, hence, EDLCs with coating electrodes with PEDOT:PSS binder can be recycled according to proposed protocols [24] based on liquid processing [25,26] and separation methods [27]. PEDOT:PSS pseudocapacitors have typically aqueous electrolytes, such as 1 M H 2 SO 4 [28] or H 3 PO 4 /PVA gel electrolyte [29,30].…”

Composite Electrodes of Activated Carbon and Multiwall Carbon Nanotubes Decorated with Silver Nanoparticles for High Power Energy Storage

“…In terms of cost, the composite coatings contain only 0.15 wt% MWCNT and only 0.015 wt% Ag materials. Where needed, the supercapacitor materials can be recycled according to established procedures [43] of disassembling the cell, washing the components, dissolving the polymer binder [44,45] and separating the solid AC, MWCNT and Ag particles via dielectrophoresis [46].…”