Kevin Mathew, Western Michigan University

Rotogravure Printing of Li Ion Battery Anodes

Kevin Mathew, Alexandra Pekarovicova, and Paul D. Fleming, III, Western Michigan University

Rotogravure inks were formulated for Li-ion battery anodes. Different polymer chemistries were tested such as polyvinylidene fluoride  (PVDF ) with degree of polymerization of 1*106. It was found that the best printability can be achieved using mixed PVDF-PVP (polyvinylidene fluoride – polyvinylpyrrolidone) binders with commercial names of PVDF being Kureha 9100, 9300, and Solef 5300. As active materials, Philips 5, 10, 15 graphites (5 -15 micron) in combination with nanocarbon filler were used. Inks were dispersed in NMP (N-methyl-pyrrolidone) solvent. The particle size of graphite for most uniform printing was found to be 5 microns. Surface energy of copper foil substrate and surface tension of inks were determined. Printed copper foils were assembled into battery half cells and their irreversible capacity loss was tested.