Microscopic Analysis of the Different Perchlorate Anions Intercalation Stages of Graphite

Abstract

Driven by the perspective of large-scale, high-quality graphene production via chemical routes, the investigation of electrochemical anion intercalation between the basal graphite planes has seen a renewed interest among the scientific community. At relatively high electrochemical potentials, when oxidation occurs,\ud graphite electrodes undergo significant anion intercalation processes. The latter swell the uppermost graphite layers (i.e., graphene sheets), reduce the interplane interaction and favor the graphite delamination\ud in liquid. Different intercalation stages are observed in a perchloric acid electrolyte, which are usually interpreted in terms of different perchlorate penetration depths. Nonetheless, the understanding of the morphological changes occurring at the electrode surface during the different intercalation stages is still not\ud completely clear. We combine different microscopy techniques including optical, scanning electron and electrochemical atomic force microscopies to analyze the morphological evolution of the graphite surface at different length scales as a function of the applied electrochemical potential. Whereas both carbon dissolution and blisters affect the surface on the micrometer scale as soon as intercalation starts, we find that the graphite surface is cracked on the sub-millimeter scale only when intercalation at a higher potential is reached, inducing a significant aging of the electrode surface

An In Situ Interface Reinforcement Strategy Achieving Long Cycle Performance of Dual‐Ion Batteries

“…Therefore, a stable stage I GIC is formed at high potential, while the fresh MCMB tends to form a highly disordered structure. Since the CO 2 release caused by EMC decomposition will further accelerate the exfoliation of graphite cathode, consecutively occurred anodic structural collapse and electrolyte decomposition finally result in the poor cyclability of the MCMB cathode. Encouragingly, by virtue of the “Great Wall” protection of synergetic LTO‐CEI network, these unfavorable interfacial parasitic reactions are effectively alleviated and the integrity of the MCMB is effectively maintained, verifying the validity of our in situ electrocatalytical strategy …”

Surface-Limited Electrodeposition of Continuous Platinum Networks on Highly Ordered Pyrolytic Graphite

“…The choice of HOPG as a model surface is due to its relative flatness as well as to its structural similarity to the graphitized regions of the surface of the carbon nanofibers and nanotubes that inspired this work [ 15 , 16 ]. Furthermore, the possibility of exfoliating HOPG to obtain graphene layers [ 17 ], which can be further catalysed with platinum, will open novel perspectives of applications.…”

Sensitive Electrochemical Determination of NADH Using an Electrode Fabricated by Intercalation of Tetrabutylammonium Ions Into Graphite Electrode

“…The syntheses, compositions, and properties of intercalated graphite electrodes containing different intercalate species have been reported in various studies. When we investigated the literature in detail, we see that the intercalation of Li + , TBA + , ClO 4 À , BF 4 À , K + , Na + , and PF 6 À species into graphite electrode materials and the use of these electrodes in application areas such as batteries and capacitors are common and remarkable [28,[33][34][35][36][37]. The use of graphite electrode intercalated with tetrabutylammonium for sensor applications is a first in the literature.…”