Cu Foil Modification By Ag Inkjet Printing for Improved Li Plating in Anode-Free Li Batteries

Abstract

The rush in the development of new generation of lithium-ion batteries (LIB) is focused on enhancing the specific energy of batteries by employing innovative materials and manufacturing techniques. Anode-free lithium metal batteries (AFLBs) are an emerging technology that can almost double the specific energy of LIBs by eliminating the conventional graphite negative electrode or excess lithium metal 1. However, AFLBs are well-known to suffer of fast capacity decay due to the poor lithium plating and stripping efficiency process associated to the typical porous growth of Li during charge 2. Tuning the interfacial electrochemistry was widely demonstrated to be one the most performing key to enable efficient and smooth Li deposition. In this regards, functional coatings of metals as Sn, Al, Zn and Ag have been widely demonstrated to dramatically improve the quality of Li plating process respect to the neat Cu foil substrate, by forming lithium-rich alloys that provide minimum Li nucleation overpotentials 3. Inkjet printing (IJP) could be a viable technique for electrode fabrication in LIBs manufacturing, being a quick, easy and scalable technology able to deposit both thin film and patterned structures 4. However, very poor attention has been paid so far to the potentiality of IJP for Cu modification for improved Li plating in AFLBs.In this work, we employed a Fujifilm Dimatix inkjet printer to achieve “lithiophilic” coatings of Ag nanoparticles deposited on a Cu foil. In particular, potenziodynamic and galvanostatic electrochemical test were employed to investigate the effect of the Ag printed structures on the Li nucleation overpotential. Ex-situ morphological analysis by electron scanning microscopy (SEM) were usefully employed to investigate the surface evolution of the printed electrodes during lithium alloying and plating. In particular, the effect pf patterned Ag structured rather than fully coated Cu was investigated, revealing that patterning can provide more mechanically robust electrode and efficient catalytic sites for Li electrodeposition respect to fully coated inkjet printed electrodes. Bibliography L. Lin et al., Advanced Materials, 34, 2110323 (2022).L. Su and A. Manthiram, Small Structures, 3, 2200114 (2022).X. Gu, J. Dong, and C. Lai, Engineering Reports, 3, e12339 (2021).P. Viviani, E. Gibertini, F. Iervolino, M. Levi, and L. Magagnin, Journal of Manufacturing Processes, 72, 411–418 (2021).