Replacement of NMP solvent for more sustainable, high-capacity, printed Li-ion battery cathodes

Abstract

The production methods of Li-ion batteries need to be adapted for the goals of a more sustainable future. This research focuses on replacing toxic NMP with less harmful solvents, without compromising the batteries' performance. From the perspective of printed electronics, the replacement is especially desirable because the aggressiveness of NMP has a negative impact on various components of printers. In this research, the novel NCM88 material has been used to fabricate the cathode layers of Li-ion batteries. Two fabrication methods (blade coating and screen printing) and two different slurry/ink formulations (NMP-and DMF-based) have been analysed. For the purpose of physicochemical and electrical characterization, the fabricated cathodes were used to assemble pouch cells and half-cells with metallic lithium as counter electrode. Results indicate that screen-printed cathodes fabricated with DMFbased slurries perform similarly to those fabricated through blade-coating NMP slurries.

Towards greener batteries: sustainable components and materials for next-generation batteries

“…Consequently, researchers are exploring green alternatives to NMP. [136][137][138] These alternatives should ideally possess similar properties to NMP, both in terms of processing and performance. The Hansen solubility sphere, a widely recognized system in chemistry for predicting material solubility, can be used to determine the suitability of solvents as potential replacements for NMP.…”

The First Edition of the World Nanotechnology Marathon [Spotlight Column]

“…The WnM was populated with talks devoted to sustainability issues and environmental remediation challenges. For instance, the development of sustainable lithium-ion batteries and solid electrolytes were debated [28], [29]. The various perspectives of nanotechnology applications in agriculture were provided [30], as well as the potential of nanomaterials as a tool in the analysis and removal of pollutants from contaminated water systems [31].…”

Various Solvent‐Binder Compositions and their Crystalline Phase for Optimal Screen‐Printing of NMC Cathodes

“…[36] Therefore, many researchers seek for green alternatives to replace NMP. [37,38] Some of the efforts involve introduction of complementary solvents, such as DMSO (Dimethylsulfoxide), Cyrene (Dihydrolevoglucosenone), or γ-Valerolactone. These solvents offer similar dissolving properties as NMP, but the formulated cathode slurries have relatively high boiling point (more energy needed for cathode drying), insert undesired sulfur impurities (DMSO), and provide cathode layers with poorer adhesion (Cyrene, or γ-Valerolactone), resulting in lower battery performance.…”