Mesopore-dominated porous carbon derived from vinasse for high performance supercapacitors with different electrolytes

Abstract

Porous carbon electrode materials with appropriate proportion of hierarchical pores are critical for high performance supercapacitors. Here, a mesopore-dominated hierarchical porous carbon was reported. KOH, melamine (MA), and the carbonized vinasse were sequentially mixed using dry ball milling, the mixture was pyrolyzed to acquire mesopore-dominated porous carbon. The pore structure can be controlled by adjusting the addition amount of melamine. The optimal sample with high meso-porosity, large total pore volume, ultrahigh specific surface area (SSA) and hydrophilicity makes it performs quite well in different electrolytes. A high specific capacity of 413 F g −1 was achieved and retained 267 F g −1 at a high rate of 50 A g −1 with excellent capacitance retention (107 % after 10000 cycles). The symmetrical supercapacitor gained a superior energy density of 16.7 Wh kg −1 , 21.2 Wh kg −1 , 54.0 Wh kg −1 in 6 M KOH, 1 M Na 2 SO 4 , 1 M Et 4 NBF 4 /ACN electrolyte, respectively. This work opens a new strategy for the preparation and high-efficient application of biomass porous carbon materials in energy storage. • Mesopore-dominant vinasse-based porous carbon. • Innovatively using dry ball milling to add melamine for mixing. • NVCP-1 with high SSA of 3442.97 m 2 g −1 and large pore volume of 2.41 cm 3 g −1 . • NVCP-1 shows excellent performance in three different electrolytes.