Matching the nanoporous carbon electrodes and organic electrolytes in double layer capacitors

Investigation of the impact of stacking pressure on a double-layer supercapacitor

“…This has two potential consequences for the operation of an EDLC cell, which may not be evident outside that particular environment: (1) a displacement of the electrolyte away from contact with the surface of the carbon electrodes and (2) a significant decrease in the accessible surface area of the carbon material due to the restriction of the transport channels [10]. Since it is well established that the extant of accessible surface area and the pore size distribution of activated carbons influence EDLC performance [7,12], the loss of accessible surface area and the displacement of electrolyte could result in a significant impact on the performance characteristics of the electrochemical capacitor [13,14]. This gives rise to the question as to what is the limit, if any, to how much force could be applied to a cell.…”

In-pore exchange and diffusion of carbonate solvent mixtures in nanoporous carbon

“…NMR diffusometry measurements employing pulsed field gradient (PFG) techniques provide a measure of the molecular self-diffusion in equilibrated system for the different chemical species present [38,39]. While there have been several NMR and molecular dynamics studies examining the selfdiffusion of molecules within porous carbon materials [40][41][42][43], few studies have examined the diffusion of electrolyte components in a NPC system relevant to supercapacitor and LIC applications [44,45], and no studies have directly measured the transport of individual chemical species in absorbed carbonate solvent mixtures. By combining 1 H HRMAS NMR with diffusometry techniques an improved understanding of solvent interactions and transport inside the pores of the carbon electrodes can be developed.…”

Experimental and theoretical studies of nonlinear dependence of the internal resistance and electrode thickness for high performance supercapacitor

“…The nonlinear results for SC R in dependent of electrode thickness in a typical carbon-based two double layer SC can effectively eliminate the arguments910111213. More importantly, a theory model based on electrochemical system “porous carbon material/organic electrolyte” was proposed for explaining the nonlinear dependence fact.…”

“…Moreover, the resistance dependence of electrode thickness is not clearly and even inconsistent in the literature reports. Some reports support this dependence is linear91011, while other ones believe that the functional dependence of SC internal resistance on electrode thickness is nonlinear1213. Therefore, experiment and theory study should be performed to discover the underlying mechanism to increase the utilization efficiency of electroactive material at large mass loading with optimized electrode thickness.…”