导电石墨烯孔道内双电层结构的研究.

In order to effectively develop and utilize new energy, people urgently need high-performance super- capacitors to provide energy storage and conversion. Electric double layer structure plays a key role in supercapacitors. In this work, the molecular dynamics simulation was taken to an open graphene nanochannel (1-2 nm), and the double-layers structure of KCl solution inside the nanochannel was studied. Meanwhile, the similarities and differences of the double-layer structure under fixed charge simulation (Q) and constant potential simulation (U) were compared. The results show that the mirror image effect of the conducting graphene wall is considered in the constant potential simulation method, which makes the results more consistent with the practical materials. The mirror image effect can absorb extra ions. Thus it enhances the concentration of anion and cation in the pore, which may contribute to the improvement of electrode capacitance. Through the study of different channel heights, it is found that water molecules play a decisive role as dielectric materials in water-based supercapacitor. It can largely offset the change of electric double layer under different ions and different channel heights, resulting in a similar capacitance under different conditions. [ABSTRACT FROM AUTHOR]