Methods of forming a lithium-based negative electrode assembly are provided. A surface of a metal current collector is treated with a reducing plasma gas so that after the treating, a treated surface of the metal current collector is formed that has a contact angle of less than or equal to about 10° and has less than or equal to about 5% metal oxides. The metal current collector may include a metal, such as copper, nickel, and iron. A lithium metal is applied to the treated surface of the metal current collector in an environment substantially free from oxidizing species. Lithium metal flows over and adheres to the treated surface to form a layer of lithium. The layer of lithium may be a thin layer having a thickness of ≥about 1 μm to ≤about 75 μm thus forming the lithium metal negative electrode assembly.