Tailoring of the pore structures of wood pyrolysis chars for potential use in energy storage applications

Abstract

Char obtained from biomass pyrolysis is an eco-friendly porous carbon, which has potential use as a material for electrodes in supercapacitors. For that application, a high microporous specific surface area (SSA) is desired, as it relates to the accessible surface for an applied electrolyte. Currently, the incomplete understanding of the relation between porosity development and production parameters hinders the production of tailor-made, bio-based pyrochars for use as electrodes. Additionally, there is a problem with the low reliability in assessing textual properties for bio-based pyrochars by gas adsorption. To address the aforementioned problems, beech wood cylinders of two different lengths, with and without pre-treatment with citric acid were pyrolysed at temperatures of 300-900°C and analysed by gas adsorption. The pyrolyzed chars were characterised with adsorption with N 2 and CO 2 to assess the influence of production parameters on the textual properties. The new approach in processing the gas adsorption data used in this study demonstrated the required consistency in assessing the micro-and mesoporosity. The SSA of the chars rose monotonically in the investigated range of pyrolysis temperatures. The pre-treatment with citric acid led to an enhanced SSA, and the length of the cylinders correlated with a reduced SSA. With pyrolysis at 900°C, the micro-SSAs of samples with 10 mm increased by on average 717 ± 32 m 2 /g. The trends among the investigated parameters and the textual properties were rationalized and provide a sound basis for further studies of tailor-made bio-based pyrochars as electrode materials in supercapacitors.

Influence of sequential HTC pre-treatment and pyrolysis on wet food-industry wastes: Optimisation toward nitrogen-rich hierarchical carbonaceous materials intended for use in energy storage solutions

“…Most of the error in the SSA result was related to the smallest pores assessed with CO 2 (pore width > 0.7 nm). A similar allocation of the SSA measurement error was observed for other bio-based pyrochars, which confirms the reliability of conducted measurements (Maziarka et al, 2021b;Maziarka et al, 2021a). All wastes processed in the one-step process do not show SSA for the pore size larger than 2 nm.…”

Multiwall carbon nanotubes derived from plastic packaging waste as a high‐performance electrode material for supercapacitors

“…The commonly used electrode materials are based on carbon (eg, carbon black, activated carbon, carbon nanotubes, etc), conducting polymers, and transition metals (eg, MnO 2 , RuO 2 , NiO), which are expensive. To this end, extensive research has been carried out to produce carbon‐based electrodes from biomass waste, such as spent tea leaves, coffee bean waste, sugarcane bagasse, and others 17‐21 . However, less attention has been paid to the use of packaging plastic waste for the development of cost‐effective carbon electrodes for energy storage applications, especially for supercapacitors.…”

Carbons Formed in Methane Thermal and Thermocatalytic Decomposition Processes: Properties and Applications

“…Electrode materials play a key role in battery development. CNTs have been studied as an anode material for Li-ion batteries [68]. Traditionally, in Liion batteries, graphite has been used as the anode material because of its good electric conductivity.…”

“…TCD-produced carbon provides a less-expensive, environmentally friendly choice for supercapacitor materials, without compromising the material properties required [68]. Porous carbon materials are attractive materials for the production of electrodes due to their high thermal and chemical stability, good electrical conductivity, and porous structure.…”