Effect of Different Kind of Binder in a MWCNT/Sulfur Composite Cathodes for Li/S Batteries

The Li-S batteries has pronounced as an excellent alternative in Li batteries, mainly due to its high theoretical specific capacity and energy density. However, the practical application of rechargeable Li/S batteries has several problems due to the low utilization of the active material and low efficiency during charge and discharge cycles. This work proposes the use different binder (PVDF, Chitosan and Nafion), with a MWCNT/S composite material, in order to improve the electrochemical behavior, due to the increases on the electronic conductivity between the MWCNT and the S, and avoid the dissolution of polisufides. The MWCNT was previously functionalized to improve the amount of active sites on their surface. The electrochemical characterization was made using EIS (Electrochemical Impedance Spectroscopy) and CV (Cyclic Voltammetry) in organic electrolyte. Also, with techniques of superficial characterization as LEIS (Localized Electrochemical Impedance Spectroscopy) and SECM (Scanning Electrochemical Microscopy), in ionic liquid, we showed the effect of the binder in the surface distribution of active sites in the composite material.