Thin Film Coatings on Lithium Metal for Secondary Lithium Batteries

Thin Film Coatings on Lithium Metal for Secondary Lithium Batteries

Stephen Lawes
Oxis Energy

As a part of the European Commission funded Horizon 2020 ALISE and ECLIPSE projects, OXIS Energy is developing thin film coatings on lithium metal anodes for rechargeable lithium-sulfur batteries. Lithium metal is highly reactive and spontaneously reacts with organic electrolyte solvents and salts, forming a solid electrolyte interphase (SEI) layer. During stripping and plating of lithium throughout cycling, the SEI fractures and exposes fresh lithium metal which then further reacts with the electrolyte. The repeated formation and fracture of the SEI layer results in the continuous consumption and eventual depletion of the electrolyte, ultimately leading to failure of the cell. We are therefore exploring a number of different passivation layers on lithium metal in order to stabilize the anode during cycling. These protective layers are more robust than the natural SEI and more effectively prevent direct contact between lithium metal and electrolyte, leading to high cycling efficiency and improved cycle life.