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The nitrogen-doped form of GUITAR (pseudo-Graphite from the University of Idaho Thermalized Asphalt Reaction) was examined by X-ray photoelectron, Raman, and X-ray diffraction spectroscopies and cyclic voltammetry (CV). Electrochemical studies indicate that N-GUITAR exhibits significant resistance to fouling by adsorption and by passivation. Unlike other carbon materials, it maintains fast heterogenous electron transfer (HET) kinetics with Fe(CN)63−/4− with exposure to air. The CV peak potential separation (ΔEp) of 66 mV increased to 69 mV in 3 h vs. 67 to 221 mV for a highly oriented pyrolytic graphite (HOPG) electrode. Water contact angle measurements indicate that N-GUITAR was able to better maintain a hydrophilic state during the 3-h exposure, going from 55.8 to 70.4° while HOPG increased from 63.8 to 80.1°. This indicates that N-GUITAR better resisted adsorption of volatile organic compounds. CV studies of dopamine also indicate N-GUITAR is resistant to passivation. The ΔEp for the dopamine/o-dopaminoquinone couple is 83 mV indicating fast HET rates. This is reflected in the peak current ratios for the oxidation and reduction processes of 1.3 indicating that o-dopaminoquinone is not lost to passivation processes. This ratio along with the minimal signal attenuation is the best reported in literature.

There have been many advancements in the search for an oxygen reduction reaction (ORR) catalyst that exhibits strong performance and exceptional durability using low-cost materials. Although recent advancements have focused on matching or surpassing the ORR performance of Pt/C, exploring ways to improve the durability of electrocatalysts on longer time scales has not been adequately addressed. In this work, a high-performance and stable ORR electrocatalyst was produced using a simple nitrogen-doping protocol on GUITAR (pseudo-Graphite from the University of Idaho Thermolyzed Asphalt Reaction)-coated Ketjen black (N′-GUITAR/KB). X-ray photoelectron spectroscopy indicates selective doping of pyridinic and pyrrolic moieties (total N abundance of 0.9%). Voltammetric experiments in O2-saturated 0.1 M KOH indicate that the electrocatalyst is exceptionally stable and one of the highest performers regarding overvoltage and current density. The system maintained its electrocatalytic performance throughout the Department of Energy stress protocol, which consists of 30,000 convective cyclic voltammetry cycles in O2-saturated 0.1 M KOH. This remarkable stability, along with the low-cost synthesis, represents an important milestone in overcoming the challenges that prevent wide-scale adoption of fuel cell technology.

The presence and stability of solid electrolyte interphase (SEI) on graphitic electrodes is vital to the performance of lithium‐ion batteries (LIBs). However, the formation and evolution of SEI remain the least understood area in LIBs due to its dynamic nature, complexity in chemical composition, heterogeneity in morphology, as well as lack of reliable in situ/operando techniques for accurate characterization. In addition, chemical composition and morphology of SEI are not only affected by the choice of electrolyte, but also by the nature of the electrode surface. While introduction of defects into graphitic electrodes has promoted their electrochemical properties, how such structural defects influence SEI formation and evolution remains an open question. Here, utilizing nondestructive operando electrochemical atomic force microscopy (EChem‐AFM) the dynamic SEI formation and evolution on a pair of representative graphitic materials with and without defects, namely, highly oriented pyrolytic and disordered graphite electrodes, are systematically monitored and compared. Complementary to the characterization of SEI topographical and mechanical changes during electrochemical cycling by EChem‐AFM, chemical analysis and theoretical calculations are conducted to provide mechanistic insights underlying SEI formation and evolution. The results provide guidance to engineer functional SEIs through design of carbon materials with defects for LIBs and beyond.

A nanocrystalline graphite-like amorphous carbon, (graphite from the University of Idaho thermolyzed asphalt reaction, GUITAR) shares morphological features with classical graphites, including basal and edge planes (BP, EP). However, unlike...