Process and apparatus for manufacturing lithium or lithium alloy thin sheets for electrochemical cells

A method of extruding lithium or lithium alloy to form a thin sheet, the method comprising the steps of:

• providing an ingot of lithium metal or lithium alloy having an initial length and diameter;
• pressing said ingot through a flow channel comprising an entrance having a first height and a first width, an exit having a second height and a second width, and a passage joining said entrance and said exit, said second width of said exit being wider than said first width of said entrance such that said lithium metal or lithium alloy exits said flow channel with a width exceeding the initial diameter of said ingot, said passage including a top wall, a bottom wall, and a pair of side walls connecting said top wall and said bottom wall, said passage defining a pair of subchannels, each subchannel running generally along a respective side wall of said passage and having a cross-sectional area adapted to:
• generate an outward flow of said lithium metal or lithium alloy away from a central portion of said passage and towards said respective side wall;
• and
• guide said lithium metal or lithium alloy generally along said respective side wall;
• and
• thereafter, extruding said lithium metal or lithium alloy through an extrusion die aperture in the form of a thin sheet.