Two steps synthesis approach of MnO2/graphene nanoplates/graphite composite electrode for supercapacitor application

MnO2/GNPs-PVDF/graphite capacitive electrode is prepared by two steps synthesis approach, where low cost graphene nanoplates (GNPs) which show the benefits of single-layer graphene and highly graphitic carbon, are initially mixed with 8 wt% polyvinylidene fluoride (PVDF) binder polymeric solution via a slurry procedure. Slurry of GNPs-PVDF composite is then pasted and pressed onto a flexible graphite substrate for the post anodic deposition of thin MnO2 film with relaxed structure. The MnO2 film deposited on GNPs-PVDF/graphite support shows better capacitive performance than that obtained by direct deposition on graphite substrate or those reported for counter electrodes prepared by one pot synthesis, as it exhibits specific capacitance (SC) of 855 F g-1 at 1.3 mA cm−2, excellent rate capability and most importantly, maintains capacitance retention (CR) of 105% after 2000 cycles of charging and discharging at 3.8 mA cm−2. This unique capacitive performance is attributed to the facilitation of ion accessibility and electron transfer through the MnO2 film, which stabilized by MnO2-GNPs bond interaction. If considering that GNPs can be easily mass produced from graphite; the structural stability and excellent capacitive performance suggest that MnO2/GNPs-PVDF composite supported on flexible graphite substrate is a promising electrode material for future energy storage applications.