LIOVIX ^® Printable Lithium Technology for Prelithiation of Silicon Anode

Loss of active lithium in the first cycle, due to SEI formation or displacement reactions permanently lowers the Lithium-ion cell energy density. Prelithiation employs an external, sacrificial source of lithium to offset these losses allowing more efficient use of lithium from the cathode and raising the cell energy density. There are many proposed pre-lithiation techniques such as roll-to-roll electrochemical baths, sacrificial salts, vacuum deposition and lithium sputtering. (1) None of these pre-lithiation methods have been scaled beyond the laboratory or pilot scale due to safety, cost, manufacturing inefficiencies or cell performance issues. Currently, the pre-lithiation method that has shown the most promise is the addition of lithium metal to the prefabricated anode (2), (3), (4) . Because of its high capacity, lithium metal causes a negligible increase in cell mass and volume. In comparison, when sacrificial salts are used, the energy density can decrease due inactive phases remaining after lithium extraction. LIOVIX ® printable lithium technology is comprised of stabilized lithium metal powder (SLMP) dispersed in a compatible solvent along with other rheology and performance modifiers to create a formulation that is chemically stable and not prone to separation for extended periods of time. The solvent used is compatible with commercial electrode slurry solvent removal and recovery practices and is less toxic than NMP. The technology is easily scalable using industry standard coating and printing equipment to apply the formulation to the surface of a prefabricated anode. LIOVIX ® is adaptable to any anode or cathode chemistry where an independent source of lithium is required. LIOVIX ® can be used in anodes with a range of silicon content, because lithium loading can be accurately controlled based on the applications’ requirements. Lithium loading control is achieved through modification of the print head to print stripes of various width and spacing on the electrode surface. The patterns can range from narrow stripes spaced evenly across the electrode to a monolithic lithium layer. In this presentation, we will show a comparison between LIOVIX ® and other prelithiation methods. The electrochemical results will be discussed as well. Reference 1. Florian Holtstiege, Peer Bärmann, Roman Nölle, Martin Winter, and Tobias Placke, Pre-Lithiation Strategies for Rechargeable Energy Storage Technologies: Concepts, Promises and Challenges, Batteries 2018, 491), 4 2. Yusuke Abe, Seiji Kumagai, Effect of negative/positive capacity ratio on the rate and cycling performances of LiFePO4/graphite lithium-ion batteries 3. Sa Li, Yunhui Huang, Ju Li et al., Roll-to-roll prelithiation of Sn foil anode suppresses gassing and enables stable full-cell cycling of lithium ion batteries. Energy Environ. Sci.,2019,12, 2991 4. Chengxu Shen, Rusheng Fu, Yonggao Xia and Zhaoping Liu, New perspective to understand the effect of electrochemical prelithiation behaviors on silicon monoxide. RSC Adv.,2018,8, 14473