Hierarchical Biocarbons with Controlled Micropores and Mesopores Derived from Kapok Fruit Peels for High-Performance Supercapacitor Electrodes

Abstract

Hierarchical microporous and mesoporous biocarbons derived from kapok fruit peels were prepared by a two-step method. First, a carbon precursor was prepared from the kapok fruit peels by precarbonization at lower temperature, and then it was activated at a higher temperature with KOH as an activation agent. Micropores and mesopores of the biocarbons were controlled by adjusting the mass ratio of KOH to the carbon precursor. Especially, the biocarbon AC4 that was prepared with a KOH/carbon precursor mass ratio of 4:1 possesses a sheet structure with hierarchical pores, a high specific surface area of 1257.6 m2/g, and a pore volume of 1.05 cm3/g. The AC4 biocarbon exhibits a maximum specific capacitance of 332.3 F/g at a current density of 1 A/g, and it still remains a specific capacitance as high as 180 F/g with increasing the current density up to 50 A/g. The AC4 electrode material also possesses an excellent life span after 10 000 cycles. On the basis of these obtained results, the relationship between the electrochemical performance and the structure of the biocarbon was discussed.

Quasi-Solid, Bio-Renewable Supercapacitors Based on Cassava Peel and Cassava Starch and the Use of Carbon Dots as Performance Enhancers

“…Both AC and CC showed a combination of micropores and mesopores in a range from 1.53 to 1.91 nm and from 2.16 to 15.13 nm, respectively, which agreed with the nitrogen adsorption–desorption isotherms. The presence of both micropores and mesopores suggested that AC is suitable for high-capacity ion and charge storage for supercapacitors as micropores support the charge storage process while mesopores allow effective ion transfer from the electrolyte. , …”

“…The presence of both micropores and mesopores suggested that AC is suitable for high-capacity ion and charge storage for supercapacitors as micropores support the charge storage process while mesopores allow effective ion transfer from the electrolyte. 30,31 3.2. Characterizations of CDs.…”

Kapok Fiber- Structure, Characteristics and Applications: A Review

“…Similarly, kapok fiber has been utilized as micro-tube biomaterial or biotemplate for electrodes in fuels cells or batteries [74][75][76][77] and supercapacitor [78][79][80] . Synthesis using simple hydrothermal method followed by calcination at high temperature and inert atmosphere was the method employed to produce an electroactive hybrid composite.…”

Suitable Micro/Mesoporous Carbon Derived from Galangal Leaves (Alpinia galanga L.) Biomass for Enhancing Symmetric Electrochemical Double‐layer Capacitor Performances

“…[23,24] Possible steps include developing a hierarchical pore framework through a combination of relatively equal micro/meso distributions. [25] This strategy has been reported to be successful by Zhang et al (2022) which synthesized pecan shell-based activated carbon through KOH impregnation. [23] They provided significantly detailed information regarding the importance of considering the micro/meso ratio of activated carbon for electrochemical double-layer capacitor applications.…”