Sustainable polylysine conversion to nitrogen-containing porous carbon flakes: Potential application in supercapacitors

The derived lysine from biomass fermentation is a naturally abundant renewable resource. However, the small molecular size of lysine limits its processing and application. On the other side, carbonization of polylysine into high-valued carbon materials is one of convenient options to apply for energy storage devices. Herein, we prepare polylysine@silica hybrid nanostructure through thermal polymerization of lysine and biosilicification of tetraethoxysilane (TEOS). Subsequently, nitrogen-containing porous carbon flakes (NPCF) are synthesized upon carbonization. Interestingly, the synthesized NPCF presents hierarchical porous framework structure with interconnected micro-meso-macro pores. Consequently, the NPCF delivers an excellent supercapacitor performance. For instance, our characterizations display specific capacitance up to 242 F/g at 1 mV/s and 186 F/g at 1 A/g, and could keep 96.3% initial capacity after 10,000 cycles at 10 A/g. These achievements are because of hierarchical porosity, proper nitrogen content, and accessible surface area of nanostructured NPCF. Therefore, our work creates a novel and sustainable route for fabricating NPCF with promising applications in the supercapacitors. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 48214.