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We systematically investigate the role of carboxymethyl cellulose (CMC) and show how it affects the slurry dispersion according to the slurry preparation process. We find that CMC plays various roles as a dispersant, thickener, and gelling agent in the anode slurry depending on its content. CMC acts as a dispersant at lower content than the optimum graft density at which the two particles (carbon black, graphite) are adsorbed and saturated. When the CMC content increases above the optimum graft density, the adsorbed CMC still acts as a dispersant, but the extra free CMC acts as a thickener or a gelling agent depending on the content. In the meanwhile, CMC shows similar adsorption and dispersion mechanism for the two particles. Therefore, at a CMC content lower than the optimum graft density, the adsorption selectivity of CMC for both particles is significantly affected by the mixing sequence of CMC and two particles, resulting in a significant difference in slurry dispersion. On the other hand, at higher CMC content, the slurry dispersion is rarely affected by the CMC mixing sequence as both particles are eventually adsorbed and saturated in the final mixing stage. This study reports for the first time that the adsorption selectivity of the binder for the two particles can be controlled through the slurry preparation process, and that the slurry dispersion can be differently affected by the preparation process depending on the binder content. [Display omitted] • Carboxymethyl cellulose (CMC) binder plays a variety of roles depending on the content. • Adsorbed CMC and free CMC differently affects the inter-particle interactions. • Mixing sequence of CMC significantly affects the slurry dispersibility at CMC content lower than the optimum graft density. • This is attributed to the adsorption selectivity of CMC on the particles. • Role of binder should be considered in designing and understanding the slurry preparation process. [ABSTRACT FROM AUTHOR]

We previously reported that lithium transition metal oxide, Li 1.14 (Ni 0.34 Co 0.33 Mn 0.33)O 2 (NCM), which are used as the cathode active material of lithium-ion batteries, was reacted with amine and graphene oxide (GO) to form composite particles. The reaction mechanism of the NCM and amine in the formation process, can be thought of as the ionic bonding reaction or the complex formation reaction between the transition metals and amine. This time, the composite reaction was carried out to elucidate this mechanism and to obtain hybrid composite particles with carbon black (CB), the anode active material of lithium-ion batteries. Hydrophilic substituents were introduced to CB surface by plasma treatment to create reaction points with organic materials. The hydrophilic CB became anionic in water and reacted with amine to form composite particles. Subsequent reaction with GO resulted in another composite particles. The hydrophilicity of the plasma-treated CBs was evaluated, and the composite state of the CBs, amines and GO was observed by scanning electron microscopy (SEM), and Raman spectral analysis was used to analyze the state change and film distribution of the particles. The fact that the hybrid composite particles were obtained by this method supports the mechanism that the NCM and amine were ionized and bound by electrostatic interaction. At the same time, it was found that even CBs had the means to enhance the reactivity, and organic and carbon materials could be easily combined. [Display omitted] • Ion-complex synthesis method enabled us to synthesize composite particles for lithium-ion batteries with multiple functions. • Plasma treatment improves the reactivity of the inert carbon black surface, making it easier to composite. • Raman can be used to analyze the bonding and dispersion state of carbon materials that could not be observed by IR or SEM. [ABSTRACT FROM AUTHOR]