Alloy electrodes for all solid state batteries and methods of making same

A method of making an anode, the method comprising:

• providing an Al-containing film comprising Al particles and a polymer binder;
• overlaying the Al-containing film with a Li foil, such that a surface of the Al-containing film and a surface of the Li foil contact each other;
• and
• pressing the Al-containing film and the Li foil together to form the anode,
• such that at least part of Li metal in the Li foil moves toward the Al-containing film,
• such that at least part of the Al particles in the Al-containing film move toward the Li foil, and
• such that the Li metal contacts surfaces of the Al particles to form particles containing lithium-aluminum alloy (LiAl) (hereinafter “LiAl-containing particles”),
• wherein the anode comprises
• a current collector;
• an anode active material layer comprising a polymer binder and particles containing lithium-aluminum alloy (LiAl) (hereinafter “LiAl-containing particles”),
• wherein the anode active material layer has a first surface facing away from the current collector and a second surface facing the current collector;
• wherein the closer to the second surface along a direction from the first surface to the second surface within the anode active material layer, generally the more lithium the LiAl-containing particles contain,
• wherein the closer to the second surface along the direction within the anode active material layer, generally the smaller the LiAl-containing particles are, and
• wherein the closer to the second surface along the direction within the anode active material layer, generally the less round the LiAl-containing particles are;
• and
• wherein molecules of the polymer binder are distributed generally throughout the anode active material layer such that a portion of at least part of the molecules of the polymer binder is interposed between two adjacent LiAl-containing particles within the anode active material layer.

An all-solid-state battery comprising:

• an anode;
• a cathode;
• and
• a solid electrolyte positioned between the cathode and the anode and configured to enable transport of lithium ions between the cathode and the anode,
• wherein the anode comprises:
• a current collector;
• an anode active material layer comprising a polymer binder and particles containing lithium-aluminum alloy (LiAl) (hereinafter “LiAl-containing particles”),
• wherein the anode active material layer has a first surface facing away from the current collector and a second surface facing the current collector;
• wherein the closer to the second surface along a direction from the first surface to the second surface within the anode active material layer, generally the more lithium the LiAl-containing particles contain,
• wherein the closer to the second surface along the direction within the anode active material layer, generally the smaller the LiAl-containing particles are, and
• wherein the closer to the second surface along the direction within the anode active material layer, generally the less round the LiAl-containing particles are;
• and
• wherein molecules of the polymer binder are distributed generally throughout the anode active material layer such that a portion of at least part of the molecules of the polymer binder is interposed between two adjacent LiAl-containing particles within the anode active material layer.