Implementing Substrate Treatments to Enhance Adhesion and Facilitate Cyrene as an NMP Alternative for Sustainable Printed Nickel–Manganese–Cobalt-Based Battery Cathodes

Abstract

This study proposes a greener approach for electrode preparation using cyrene, a bio-derived and fully biodegradable green solvent, as a potential N-methyl-2-pyrrolidone substitute for fabricating high-performance nickel–manganese–cobalt oxide (NMC88) lithium-ion battery cathodes by screen-printing method. This study also investigates the replacement of the polyvinylidene fluoride (PVDF) binder with Arkema Kynar HSV1810 homopolymer, a crucial substitution for enabling the effective utilization of cyrene, addressing the solvent inadequacy associated with PVDF dissolution. Alongside the ink formulation, the electrode preparation process is optimized by investigating current collector surface treatments using plasma, ultraviolet, and citric acid to enhance substrate wetting, leading to improved printability, adhesion, and cathode layer performance. Cyrene-based screen-printed NMC cathodes are analyzed using various characterization techniques, including microscopy, optical profilometry, scanning electron microscopy, adhesion tests, and electrochemical performance tests for assembled batteries. The results demonstrate that cyrene-based slurries exhibit improved wettability and adhesion on substrates/current collectors when surface treatments are applied. Furthermore, the electrochemical performance of cells based on surface-treated NMC88 electrodes prepared with cyrene shows adequate cycling performance and rate capability. As a proof of concept, the study presents an alternative green and sustainable approach for electrode preparation in screen-printed Li-ion batteries using cyrene.