Non-graphitizable carbon has attracted much attention because it ideally has a larger alkali metal ion capacity than graphite. The behavior of alkali metal ions at the non-graphitizable carbon/electrolyte interface has not been clarified. In this work, the influence of electrolyte and solid electrolyte interface (SEI) on the alkali metal ion transfer resistance to non-graphitizable carbon was investigated separately. In lithium-ion transfer reaction, the resistance value was significantly small, independent of either electrolyte or SEI. On the other hand, the sodium-ion transfer reaction showed a much larger difference depending on SEI than electrolyte, and SEI derived from fluoroethylene carbonate (FEC) had a larger resistance. FEC-based SEI had large amount of NaF. The results of this study revealed that it is important to construct an optional SEI to reduce the sodium-ion transfer resistance to non-graphitizable carbon.

Graphite intercalation compounds (GICs) have been extensively studied; however, their visual appearance has not been systematically documented. The appearance of GICs plays a crucial role in understanding their properties and potential applications. In this study, alkali metal GICs (Li-, Na-, K-, Rb-, and Cs-GICs), known for their vivid gold and blue colors, were synthesized using a common host graphite under standardized conditions. Photographs were taken under controlled settings to capture their visual appearance, and reflectance spectra were measured to provide objective optical data, contributing to a standardized color sample compilation. Additionally, their structures and electrical conductivities were evaluated. Furthermore, the relationship between the crystallinity of the host graphite and the perceived appearance of the GICs is discussed. This study provides a comprehensive reference dataset on GIC appearance and is expected to support future research on intercalation compounds.

Density (ρ) of ultra-thin graphite films whose thickness are 41 - 300 nm was experimentally determined by a sink-floating method using solvents of acetone and diiodomethane. The films were synthesized from the heat treatment of spin-coated benzimidazobenzophenanthroline ladder (BBL) polymer films. The measured ρ of the films decreased as the thickness become thinner, and the thinnest film of 41-nm thick takes the lowest ρ of 1.76 ± 0.01 g/cm³. From the characterization of the films by the X-ray absorption near-edge structure (XANES) measurements in the CK region, it can be clarified that the films are surely graphite and their orientation of the graphitic structure is much disordered as the thickness becomes thinner. It is therefore considered that thinner graphitic films with the several tens–hundreds nm thick take lower ρ due to the much-disordered graphitic local structures.

We have prepared an aqueous dispersion ink of single-walled carbon nanotube (SWCNT) for screen-printing. In this preparation, poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT:PSS) was utilized to improve the dispersion of SWCNT in an aqueous solution, and dimethyl sulfoxide (DMSO) was added to the SWCNT/PEDOT:PSS inks to improve the ink dispersion and adjust the ink viscosity for screen-printing, as well as increasing the film conductivity by a secondary doping effect to PEDOT:PSS. By optimizing the volume ratio of the DMSO addition to PEDOT:PSS, suitable ink viscosities for screen-printing were obtained. The films fabricated on water-resistant paper substrates by screen-printing using the SWCNT/PEDOT:PSS/DMSO ink with a DMSO addition ratio of 75% showed a low sheet resistance of 4.0 ± 0.4 Ω/sq without any post-treatment such as high-temperature heating or acid treatment. Aqueous inks for screen-printing of low-resistance films will be useful for various applications such as microwave and circuit devices, which require low-resistance and flexible conductive films on chemically fragile substrates like papers.

The objective of this field experiment was to quantify changes in total carbon (TC), total organic carbon (TOC), total inorganic carbon (TIC), residual oxidizable carbon (ROC), and dissolved organic carbon (DOC) in perennial pasture soils planted with white clover (Trifolium repens) and tall fescue (Festuca arundinacea). Treatments included ammonium sulfate (AS), and urea (U) fertilizers applied with rice husk biochar (700 °C) at 5 t ha⁻¹ (B5) and 10 t ha⁻¹ (B10). Biochar–N treatments increased TOC, TIC, and ROC more than sole N treatments, with exceptions for TIC in ASB5 (white clover) and UB5 and ASB10 (tall fescue). In white clover, TC increased more under biochar-N treatments, particularly ASB10 and UB10, which also showed the least TOC reductions and the highest ROC increases. In white clover, UB5 and UB10 increased DOC losses more than U alone, likely due to increased microbial activity and DOC mineralization. In tall fescue, ASB5 and ASB10 reduced DOC losses more than AS, likely due to biochar's DOC sorptive potential and reduced microbial decomposition. U treatment resulted in higher TC, TOC, ROC TIC, and DOC percentage changes than AS treatment in both pastures. TC correlated positively with TIC, TOC, ROC, DOC, soil nitrogen, exchangeable calcium, and pH. Overall, U with high-rate biochar improved carbon stabilization in white clover, while AS with biochar reduced DOC losses in tall fescue

Hydrothermal treatment and carbonization of various residues from the extraction of beverages, namely coffee grounds and tea leaves, were performed to investigate the morphological properties and the potential for ethene adsorption of the resulting carbons. Hydrothermal treatment promoted the pore development of the carbons. Removal of crystalline fatty acid produced by hydrothermal treatment with ethanol washing before carbonization significantly increased the BET specific surface area, especially in coffee grounds. The carbonization process contributed to the development of ultra-micropores due to the pyrolysis of the cellulose components in as-received residues. Such narrower pores in the carbons functioned effectively for ethene adsorption.

We evaluated the effect of the molecular structure of lithium naphthalenide derivatives on the lithium doping depth, for a simple pre-doping method for natural graphite electrodes by immersing in 2-methyltetrahydrofuran (2-MeTHF) solution of lithium naphthalenide derivatives. To increase the reducing ability of lithium naphthalenide, multiple kinds of naphthalene derivatives having electron-donating substituents on the aromatic ring were examined. As a result, it was found that when a radical anion solution prepared from a 1 mol kg^-1 solution of 1,5-dimethylnaphthalene in 2-MeTHF and an excess amount of lithium metal was used, the doping depth of 88 mAh g^-1 could be achieved by immersion for 1 hour at room temperature. This method may be potentially applied as a pre-doping method for the negative electrodes for electrochemical energy storage devices.

This report presents a simple, low-cost thermal chemical vapor deposition method using alcohol as a carbon source for producing micron-sized carbon nanowalls (CNWs) on spherical carbon particles. The obtained CNWs have structural disorder and defects, as indicated by a low I_G/I_D (the ratio of the D-band peak to the G-band peak) ratio in the Raman spectrum. It is worth noting that the height and width of the CNWs reach approximately 10 µm, making them larger than previously reported CNWs. CNWs are produced at 730°C when using a tungsten mesh heater, while submicron-sized amorphous carbon grains are produced with a tungsten plate heater. However, CNWs are not produced at 800°C, even with a tungsten mesh heater. The reason why CNWs are not produced at 800°C remains unclear; however, their growth at 730°C is attributed to the preferential production of sp² carbon.