Compression means for Li-metal anode electrochemical cells

An assembly of a battery pack, the assembly comprising:

• a. a first plate;
• b. a second plate opposing the first plate;
• and
• c. a compressible sheet mounted to one of the first and second plates so that the compressible sheet is positioned between opposing faces of the first and second plates, wherein upon application of an external compression to the compression assembly of 1.3 MPa for a minute, the compressible sheet exerts an average normal pressure on a lithium metal battery cell positioned between the first and second plates, and after removal of the external compression, the compressible sheet exerts another average normal pressure that is at least 65% of the average normal pressure during the application of the external compression, and wherein the normal pressure on the cell after removal of the external compression has a variation of less than 65% across the surface of the lithium metal battery cell.