COMPOSITIONS AND METHODS FOR MULTILAYER ELECTRODE FILMS
Provided herein are energy storage device electrode films comprising multiple active layers, and methods of forming such multiple active layer energy storage device electrode films. Each active layer may be a self-supporting active layer comprising a binder and an active material. The binder and/or active material may be the same or different as any other active layer. The active layers may be stacked to form an electrode film, and the electrode film may be laminated with a current collector to form an electrode.
1 . A method of fabricating a multilayer electrode film comprising:
providing a first active layer comprising a first active material and a first binder, wherein the first active layer is a free-standing film;
providing a second active layer comprising a second active material and a second binder, wherein the second active layer is a free-standing film; and
stacking the first active layer to the second active layer to form a multilayer electrode film, wherein the multilayer electrode film is a free-standing film;
wherein the method is a dry fabrication process and the first and second active layers are substantially free of solvent residue.
2 . The method of claim 1 , wherein stacking of the first active layer to the second active layer is performed by a calendering process.
3 . The method of claim 1 , wherein stacking of the first active layer to the second active layer is performed by a pressing process.
4 . The method of claim 1 , wherein each of the first and second active materials individually comprises a metal oxide or a metal sulfide.
5 . The method of claim 1 , wherein the multilayer electrode film has a thickness of at least 200 μm.
6 . The method of claim 1 , wherein each of the first and second active layers individually have a thickness of 120-250 μm.
7 . The method of claim 1 , wherein the first and second active layers have substantially identical thicknesses.
8 . The method of claim 1 , wherein the first active layer is immediately adjacent to the second active layer.
9 . The method of claim 1 , wherein the multilayer electrode film further comprises a third active layer comprising a third active material and a third binder.
10 . The method of claim 1 , wherein the multilayer electrode film further comprises an adhesive layer.
11 . A method of fabricating a multilayer electrode comprising:
fabricating a first multilayer electrode film according to the method of claim 1 ;
providing a current collector comprising a first side and a second side; and
laminating the first multilayer electrode film to the first side of the current collector to form a multilayer electrode.
12 . The method of claim 11 , wherein the first multilayer electrode film is laminated directly onto the first side of the current collector.
13 . The method of claim 11 , wherein an intervening adhesive layer is not provided between the multilayer electrode film and the current collector.
14 . The method of claim 11 , wherein laminating the first multilayer electrode film to the first side of the current collector is performed by a calendering process.
15 . The method of claim 11 , wherein laminating the first multilayer electrode film to the first side of the current collector is performed by a pressing process.
16 . The method of claim 11 , further comprising:
providing a second multilayer electrode film; and
laminating the second multilayer electrode film to the second side of the current collector to form a double sided multilayer electrode.
17 . A method of fabricating a multilayer electrode comprising:
providing a first active layer comprising a first active material and a first binder, wherein the first active layer is a free-standing film;
providing a second active layer comprising a second active material and a second binder, wherein the first active layer is a free-standing film;
stacking the first active layer to the second active layer; and
laminating the first active layer to a current collector;
wherein the method is a dry fabrication process and the first and second active layers are substantially free of solvent residue.
18 . The method of 17 , wherein laminating the first active layer to the current collector precedes stacking the first active layer to the second active layer.
19 . The method of 17 , wherein stacking the first active layer to the second active layer precedes laminating the first active layer to the current collector.
20 . The method of claim 17 , further comprising:
providing a second multilayer electrode film; and
laminating the second multilayer electrode film to the second side of the current collector to form a double sided multilayer electrode.
21 . The method of claim 20 , wherein the first multilayer electrode film is of the opposite polarity as the second multilayer electrode film.
22 . The method of claim 20 , wherein the first multilayer electrode film and the second multilayer electric film are symmetric with respect to each other.
23 . The method of claim 20 , wherein the first multilayer electrode film and the second multilayer electrode film are asymmetric with respect to each other.
24 . The method of claim 23 , wherein the first multilayer electrode film comprises a different number of layers than the second multilayer electrode film.
25 . The method of claim 23 , wherein the active layer of the first multilayer electrode film that is immediately adjacent to the first side of the current collector has a different composition than the active layer of the second multilayer film that is immediately adjacent to the second side of the current collector.