Almond gum derived activated biocarbons as the efficient electrode material for symmetric supercapacitors
摘要
Almond gum derived biochar (obtained at 400 oC) was productively converted into activated biocarbon by KOH mediated chemical activation with varying KOH concentration at 800 oC for 1 h under N2 atmosphere. It was identified that the increasing KOH concentration in biochar increases their specific surface area. The highest specific surface area of 3525 m2/g was observed for the activated carbon synthesized employing biochar: KOH ratio of 1:1.5, whereas the respective pristine carbon showed only 221 m2/g. In addition, Raman analysis shows the increased disorder nature of biocarbon materials from 1.19 to 1.27 (ID/IG ratio) due to the activation. The obtained pristine and activated biocarbon materials were successfully used as the electrode material for the construction of symmetric supercapacitor employing 1 M KOH as electrolyte. The highest specific capacitance of 115.5 F/g at 1 A/g with the double layer capacitance contribution of 74.4% (as estimated via Trasatti method) was obtained for the activated biocarbon prepared with the biochar: KOH ratio of 1:1.5. It was also observed that 97% initial capacity retention over 500 cycles along with the maximum energy density 4.11 Wh/kg for the power density of 250.55 W/kg. These results indicate that the almond gum is a suitable environmental friendly precursor for the fabrication of activated biocarbon material for energy storage applications.