Application of Stabilized Lithium Metal Powder (SLMP®) in Graphite Anode – a High Efficient Prelithiation Method for Lithium-Ion Batteries

Stabilized Lithium Metal Powder (SLMP®) was applied in graphite anode and the effects of this prelithiation method to cell performance were investigated. Performance of prelithiated cells was compared with that of regular graphite based cells. In this study, The SLMP was loaded directly on top of dried anode laminate graphite anode since this is a relatively simple way to apply SLMP. To investigate the impact of SLMP on the SEI formation, cells assembled with SLMP prelithiated graphite anodes were allowed to rest for a period of time at open circuit before cycling. Impact of SLMP on graphite performance was first studied based on lithium metal counter electrode cells (half cells). Upon prelithiation with SLMP, changes of the voltage profile and first cycle Coulombic efficiency were examined. After that, performance of the cells containing prelithiated graphite anode and Li(Ni_1/3Mn_1/3Co_1/3)O₂ (NMC) cathode (full cell) was studied.  The first cycle capacity loss of SLMP prelithiated cell was largely reduced and the corresponding first cycle Coulombic efficiency was significantly improved. The graphite/NMC cell with SLMP prelithiation but without any standard cell formation process showed better cycle performance than that of none SLMP containing cell with standard formation process.  Prelithiation of graphite electrode with SLMP promote stable solid electrolyte interface (SEI) formation on the surface of graphite anode. Application of SLMP in lithium-ion battery thus provides an effective method to enhance capacity, and promises a low cost SEI formation process. This also implies the potential use of other promising anode materials, such as Si and Sn that have large first cycle capacity loss, in commercial lithium-ion batteries.