Gravure-Printed High-Energy Cathodes for Lithium-Ion Batteries Based on NMC 111 Active Material: The Challenge of Ink Formulation

In the context of an increasing demand for electricity, batteries increasingly appear as one of the main sources of power supply. In particular, research on batteries is mainly focused on new and high-performance materials, and innovative and more sustainable production processes. This work addresses both aspects by developing a gravure-printed cathode based on lithium nickel manganese cobalt oxide (NMC 111, LiNi0.33Mn0.33Co0.33O2). To this end, the formulation of a gravure-printable ink was investigated in order to meet both the printing and functional requirements. The formulation of a multicomponent dispersion able to produce a cathodic layer was particularly challenging, since such a system was found to be highly sensitive to the composition and specific interactions among the active material and the other components involved in ink preparation. Although a methodology based on Ca, aimed at obtaining layers with high macroscopic printing quality, was adopted, only a few printable inks having similar characteristics were obtained. From a microscopic point of view, printing allowed the identification of the best ink formulation able to produce the greatest layer homogeneity, thus yielding the best possible performance (150 mAh g−1 at C/20).