Effect of Ball Milling on the Electrochemical Performance of Activated Carbon with a Very High Specific Surface Area

Abstract

Activated carbon (AC) with a very high specific surface area of >3000 m2 g−1 and a number of course particles (average size: 75 µm) was pulverized by means of planetary ball milling under different conditions to find its greatest performances as the active material of an electric double-layer capacitor (EDLC) using a nonaqueous electrolyte. The variations in textural properties and particle morphology of the AC during the ball milling were investigated. The electrochemical performance (specific capacitance, rate and cyclic stabilities, and Ragone plot, both from gravimetric and volumetric viewpoints) was also evaluated for the ACs milled with different particle size distributions. A trade-off relation between the pulverization and the porosity maintenance of the AC was observed within the limited milling time. However, prolonged milling led to a degeneration of pores within the AC and a saturation of pulverization degree. The appropriate milling time provided the AC a high volumetric specific capacitance, as well as the greatest maintenance of both the gravimetric and volumetric specific capacitance. A high volumetric energy density of 6.6 Wh L−1 was attained at the high-power density of 1 kW L−1, which was a 35% increment compared with the nonmilled AC. The electrode densification (decreased interparticle gap) and the enhanced ion-transportation within the AC pores, which were attributed to the pulverization, were responsible for those excellent performances. It was also shown that excessive milling could degrade the EDLC performances because of the lowered micro- and meso-porosity and the excessive electrode densification to restrict the ion-transportation within the pores.

Enhanced Electrochemical Performance of Sugarcane Bagasse-Derived Activated Carbon via a High-Energy Ball Milling Treatment

“…The results show that increasing the milling speed caused a decrease in the particle size, with average particle size of about 0.4–1 µm, compared to 10–30 µm for the AC powder. The reduction of particle sizes via HEBM is in good agreement with a previous report [ 26 ].…”

“…Accordingly, activated carbon from sugarcane bagasse is considered a novel material for supercapacitor electrodes [ 22 , 23 , 24 ]. Nevertheless, high-surface area and micropores in carbon material electrodes are not the only factor needed for high performance [ 25 , 26 ]. Mesopores (pore diameters of 2–50 nm) shorten the transport paths of electrons and ions, which can also enhance the electrical performance of the materials [ 27 ].…”

Chemically Synthesized Cu3Se2 Film Based Flexible Solid-State Symmetric Supercapacitor: Effect of Reaction Bath Temperature

“…Therefore, understanding the relationship between effects of changes in basic properties of a thin-film material caused by reaction temperature on the electrochemical performance is necessary and practically significant. Such type of study will help to optimize electrode active material to achieve high rate capacity and stability. , …”

Iron-Based Electrocatalysts for Energy Conversion: Effect of Ball Milling on Oxygen Reduction Activity

“…Also, a FePc/carbon mass ratio up to 1:1 was found to lead to a uniform adsorption, which corresponds to nearly two molecular layers of FePc on carbon particles, indicating a decrease in iron(II) phthalocyanine agglomeration [24]. The effect of ball-milling on physical and electrochemical properties of the resulting catalyst materials, including surface area, porosity and specific capacitance, was widely studied throughout in the literature [46][47][48], but its effect on ORR activity in neutral media is still poorly explored. This investigation is of paramount importance to assess the material's applicability in BESs.…”