Biomass-Derived Porous Carbons Derived from Soybean Residues for High Performance Solid State Supercapacitors

• Published in: Molecules (Basel, Switzerland) Vol. 25; no. 18; p. 4050
• Main Authors: Chung, Hsiu-Ying, Pan, Guan-Ting, Hong, Zhong-Yun, Hsu, Chun-Tsung, Chong, Siewhui, Yang, Thomas Chung-Kuang, Huang, Chao-Ming
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 04.09.2020; MDPI
• Subjects: Activated carbon; Adsorption; Aqueous solutions; Batteries; Biomass; biomass-derived porous carbon; Capacitance; Carbon - chemistry; Crop residues; Electric Capacitance; Electrochemical analysis; Electrochemistry; Electrodes; Electrolytes; Energy; Energy storage; Flux density; Functional groups; Glycine max - chemistry; hydrothermal carbonization; Morphology; Nitrogen; Nitrogen - chemistry; Oxygen content; Photoelectron Spectroscopy; Pore size; Porosity; Residues; Size distribution; Solid state; solid state electrolyte; soybean residues; Soybeans; Spectrum Analysis, Raman; supercapacitor; Supercapacitors; Surface area; Synergistic effect; hydrothermal carbonization; soybean residues; biomass-derived porous carbon; solid state electrolyte; supercapacitor
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules25184050

A series of heteroatom-containing porous carbons with high surface area and hierarchical porosity were successfully prepared by hydrothermal, chemical activation, and carbonization processes from soybean residues. The initial concentration of soybean residues has a significant impact on the textural and surface functional properties of the obtained biomass-derived porous carbons (BDPCs). SRAC5 sample with a BET surface area of 1945 m g and a wide micro/mesopore size distribution, nitrogen content of 3.8 at %, and oxygen content of 15.8 at % presents the best electrochemical performance, reaching 489 F g at 1 A g in 6 M LiNO aqueous solution. A solid-state symmetric supercapacitor (SSC) device delivers a specific capacitance of 123 F g at 1 A g and a high energy density of 68.2 Wh kg at a power density of 1 kW kg with a wide voltage window of 2.0 V and maintains good cycling stability of 89.9% capacitance retention at 2A g (over 5000 cycles). The outstanding electrochemical performances are ascribed to the synergistic effects of the high specific surface area, appropriate pore distribution, favorable heteroatom functional groups, and suitable electrolyte, which facilitates electrical double-layer and pseudocapacitive mechanisms for power and energy storage, respectively.