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[Display omitted] • Dispersion/aggregation of acetylene black determines settling time of cathode slurry. • Strength and recoverability of conductive network structure affect cathode properties. • Hydrostatic pressure change of slurry linked to cathode density/volume resistivity. Hypothesis: It is important to elucidate the effect of the particle dispersion/aggregation state of electrode slurries on resulting electrodes for the development of superior lithium-ion batteries. Many studies have been conducted to characterize cathode slurries for lithium-ion batteries; however, the particle dispersion state of cathode slurries remains unclear. This study investigates the rheological behavior and the packing ability of the cathode slurries for obtaining a denser electrode with lower electric resistance. Experiments: In addition to the conventional flow curve measurement, we measured the changes in the hydrostatic pressure of the slurries with time to evaluate their packing ability. The relationship between the properties of the cathode slurries and those of the as-cast cathodes was also investigated. Findings: It was found that a slurry in which acetylene black powder forms a network structure, with sufficient strength and the ability to rapidly recover after breaking, yields a cathode with comparatively high density and comparatively low volume resistivity. It was also found that the normalized settling time of a cathode slurry determined from its change in hydrostatic pressure over time correlates well with both the density and volume resistivity of a resulting as-cast cathode. [ABSTRACT FROM AUTHOR]

Graphical abstract Obtained by a solution-based acid-pasting approach, the composite of perylene diimide and carbon black (PTCDI/CB) exhibits excellent electrochemical performances as the organic cathode material in both lithium and sodium ion batteries. Abstract An acid-pasting approach is developed in this work to fabricate the composite of perylenetetracarboxylic diimide (PTCDI) and carbon black in concentrated sulfuric acid. Different from traditional mechanical mixing, the solution-based fabrication strategy enables the sufficient blending of PTCDI as active component and carbon black as conductive agent in the PTCDI/CB composite. Serving as the cathode material, the PTCDI/CB composite shows excellent electrochemical performances in both lithium ion battery (137 mAh g−1 at 100 mA g−1 and 110 mAh g−1 at 2000 mA g−1) and sodium ion battery (134 mAh g−1 at 100 mA g−1 and 99 mAh g−1 at 1000 mA g−1), which are comparable to the state-of-art organic/inorganic cathode materials. Considering the simplicity of the processing procedures and the low cost of the starting materials, the acid-pasting approach is a highly attractive method for the solution-based manufacturing of organic secondary battery electrodes. [ABSTRACT FROM AUTHOR]