Interlinked Porous Carbon Nanoflakes Derived from Hydrolyzate Residue during Cellulosic Bioethanol Production for Ultrahigh-Rate Supercapacitors in Nonaqueous Electrolytes

The rapid development of cellulosic bioethanol has produced a mass of hydrolysate residue as byproducts during the pretreatment process of lignocellulose. The high value-added utilization of hydrolysate residue plays a key role in the economic viability of large-scale/green industrial production of lignocellulose into bioethanol. Here the hydrolyzate residue was exploited as a carbon precursor for the fabrication of an interlinked graphitized porous carbon nanoflake (GPCNF) by an in situ carbonization–activation process. The final GPCNF presents an optimum integration of a large surface area of 2026 m2 g–1, bimodal pore systems (86% of mesopore volume), and an excellent electric conductivity of 5.4 S cm–1. These characteristics favorably endow that the GPCNF is ideally suited for nonaqueous electrolyte-based supercapacitor applications. In organic electrolyte of 1 M TEA BF4/AN, the GPCNF-based supercapacitor exhibits a high rate capability of 74% initial capacitance at a high current density of 100 A g–1....