Abstract
In this study, low-density polyethylene (LDPE)-derived activated carbons (PE-AC) were prepared as electrode materials for an electric double-layer capacitor (EDLC) by techniques of cross-linking, carbonization, and subsequent activation under various conditions. The surface morphologies and structural characteristics of the PE-AC were observed by field-emission scanning electron microscope, Cs-corrected field-emission transmission electron microscope, and X-ray diffraction analysis, respectively. The nitrogen adsorption isotherm-desorption characteristics were confirmed by Brunauer–Emmett–Teller, nonlocal density functional theory, and Barrett–Joyner–Halenda equations at 77 K. The results showed that the specific surface area and total pore volume of the activated samples increased with increasing the activation time. The specific surface area, the total pore volume, and mesopore volume of the PE-AC were found to be increased finally to 1600 m2/g, 0.86 cm3/g, and 0.3 cm3/g, respectively. The PE-AC also exhibited a high mesopore volume ratio of 35%. This mesopore-rich characteristic of the activated carbon from the LDPE is considered to be originated from the cross-linking density and crystallinity of precursor polymer. The high specific surface area and mesopore volume of the PE-AC led to their excellent performance as EDLC electrodes, including a specific capacitance of 112 F/g.
Highlights
Electric double-layer capacitors (EDLC) are reported to have better performance than secondary batteries in terms of power density (>4000 W/kg) and cycle stability (>100 k cycles), but have lower energy density (1 to 5 Wh/kg) [1,2,3]
Since the energy density of EDLC is proportional to the specific surface area of the active materials in the electrodes, many researchers have focused on developing activated carbon materials which can offer both high specific surface area and excellent electrical conductivity [1,5]
The process of producing Activated carbons (AC) from low-density polyethylene (LDPE) by H2O activation was optimized and the textural properties and electrochemical characteristics of the produced materials were confirmed by applying them in EDLC
Summary
Electric double-layer capacitors (EDLC) are reported to have better performance than secondary batteries in terms of power density (>4000 W/kg) and cycle stability (>100 k cycles), but have lower energy density (1 to 5 Wh/kg) [1,2,3]. Many researchers have suggested that if the crystallite structure of the precursor can be controlled, activated carbons with excellent pore characteristics can be produced using a physical activation method, under proper process conditions [13,14,15,16,17]. The physical oxidation of large sized crystallites is quite difficult, due to the high thermal stability of graphite-like crystallite structures produced by the heavy aromatic ring structure during the carbonization process [16,17,29] This is why most studies are carried out using the chemical activation process. This study investigated the synthesis of LDPE by the physical activation method to produce AC for EDLC with well-controlled pore characteristics by controlling the crystallite structure of the cross-linked and carbonized LDPE. We prepared various low-density polyethylene derived activated carbons (PE-AC) and the electrochemical performance of the EDLC was measured in terms of the pore structure of the PE-AC
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call