Mechanochemical Processing of Natural Graphite under Different Atmospheres for Fabricating Electrodes Used in Electric Double-layer Capacitors

Abstract

This study focused on the mechanochemical processing of natural graphite using a planetary ball mill under different atmospheres and analyzing their influence on the electrochemical behaviors of the processed graphite materials in electric double-layer capacitors (EDLCs). Oxygen and/or nitrogen were incorporated in the carbon framework from the atmosphere used during milling. Specific surface areas of the pulverized graphite did not significantly depend on the employed atmosphere. These pulverized graphites processed under different atmospheres were evaluated as electrode materials for application in EDLCs with an organic electrolyte. All the pulverized graphites showed comparable capacitances independently of the used atmospheres. Considering the effect of post-thermal treatment of the pulverized graphite to remove oxygen surface functionalities, changes in the surface functionalities of pulverized graphites caused by ball milling did not significantly influence their applications as electrode materials in EDLCs.

Electrochemically Versatile Graphite Nanoplatelets Prepared by a Straightforward, Highly Efficient, and Scalable Route

“…The mechanism involved in the synthesis of GNP from tubular CNF is driven by a mechanochemical reaction. − High-speed ball-milling generates enough kinetic energy that is transferred to the graphitic framework, producing the homolytic cleavage of the graphitic C–C bonds, and the consequent formation of radicals (activated carbon species made of highly reactive dangling bonds), together with the carbon delamination. In our conditions, the ball-milling process of CNF involves first the bond cleavage of graphitic C–C frameworks on the CNF external surface and the graphene nanocones and then the physical delamination of the smashed graphene stacks (Figure a).…”

Electrochemical and physical properties of pulverized graphite for use in electric double layer capacitors

“…The capacitive behavior of the pulverized graphite was evaluated in 1 M tetraethylammonium tetrafluoroborate in propylene carbonate. The electrochemical measurements were performed using a two-electrode configuration, and the experimental details have been described previously [37,38]. on the total mass of the two electrodes, including acetylene black and binders (styrene-butadiene rubber and carboxymethyl cellulose), the gravimetric capacitance at 0.1 A g −1 was 12.5 F g −1 .…”

“…According to the literatures primarily focused on EDLC applications, rotational speeds were 200-400 rpm and the maximum specific surface area was 580 m 2 g −1 . This account paper summarizes the author's recent work on ball milling of graphite at higher rotational speeds of >500 rpm, together with the electrochemical and physical properties of pulverized graphite for use in EDLCs with organic electrolyte [37,38].…”

“…Pristinedenotes natural graphite used as a precursor. Reproduced from Ref [38]. with permission of the Electrochemical Society of Japan.…”

Single-step Synthesis of Highly Porous Nitrogen-doped Carbon by Solid–gas Mechanochemical Treatment as an Oxygen Reduction Electrocatalyst

“…Recently, solidgas mechanochemical treatments (MTs) under nitrogen-containing atmospheres such as N 2 and air have been investigated to prepare nitrogen-doped graphite and nitrogen-doped graphene-based materials. 10,11 However, only a limited number of studies have been conducted on solid-gas MT as a post-treatment nitrogen doping method for PCs, and most of these studies have focused on applications in supercapacitors and Li-ion batteries. 11,12 In the present study, we synthesized nitrogen-doped porous carbons (N-PCs) by solid-gas MT using CB as a carbon source and investigated the influence of MT on the oxygen reduction activity of the resulting N-PCs.…”