METHOD OF PRODUCING AN ELECTROCHEMICAL CELL AND ARTICLES PRODUCED THEREFROM
A method of producing an electrode assembly comprises positioning a first adhesive between a first surface of a first electrode layer having a width W e1 , and a first surface of a microporous separator layer having a width W m at an edge of the first electrode layer and an edge of the microporous separator layer, to form a first separator/electrode pre-assembly, wherein the first adhesive has a width W a1 less than ½(We el ); and adhering the first surface of the first electrode layer to the first surface of the microporous separator layer via the adhesive to form a first separator/electrode assembly. The adhesive can be a thermoplastic polymer, and can be a film and/or powder.
1 . A method of producing an electrode assembly, comprising:
positioning a first adhesive between a first surface of a first electrode layer having a width W e1 , and a first surface of a microporous separator layer having a width W m at an edge of the first electrode layer and an edge of the microporous separator layer, to form a first separator/electrode pre-assembly, wherein the first adhesive has a width W a1 less than ½(W e1 ); and
adhering the first surface of the first electrode layer to the first surface of the microporous separator layer via the adhesive to form a first separator/electrode assembly.
2 . The method of claim 1 , wherein the adhesive is a thermoplastic polymer.
3 . The method of claim 2 , wherein the thermoplastic polymer is polyethylene, polypropylene, polybutylene, polybutadiene, polytetrafluoroethylene, poly(1,1-difluoroethylene-co-hexafluoropropylene, or a combination comprising at least one of the foregoing thermoplastic polymers.
4 . The method of claim 1 , wherein the first adhesive has a width W a1 less than ¼(W e1 ).
5 . The method of claim 1 , wherein the first electrode is an anode.
6 . The method of claim 5 , wherein the anode comprises carbon deposited on a layer of a copper foil.
7 . The method of claim 1 , wherein the first electrode is a cathode.
8 . The method of claim 7 , wherein the cathode comprises a lithium active material deposited on an aluminum foil.
9 . The method of claim 1 , wherein the microporous separator comprises a microporous polyolefin membrane, a microporous fluorinated polyolefin membrane, or a microporous xerogel.
10 . The method of claim 9 , wherein the polyolefin is polyethylene, polypropylene, or a copolymer thereof.
11 . The method of claim 9 , wherein the fluorinated polyolefin is selected from polytetrafluoroethylene and polyvinylidene fluoride.
12 . The method of claim 9 , wherein the xerogel is pseudo-boehmite.
13 . The method of claim 1 , wherein adhering is effected thermally and under pressure.
14 . The method of claim 1 , wherein adhering is by laminating the separator/electrode pre-assembly using roll lamination, double belt press lamination, or flat bed lamination.
15 . The method of claim 1 , further comprising disposing a second adhesive between a second surface opposite the first surface of the microporous separator and a first surface of a second electrode having a width W e2 , at the edge of the separator and the second electrode, to form a second separator/electrode pre-assembly, wherein the second adhesive has a width W a2 less than ½(W e2 ).
16 . The method of claim 15 , wherein forming the second separator/electrode pre-assembly is prior to or after laminating the first separator/electrode pre-assembly.
17 . The method of claim 15 , comprising laminating the second separator/electrode pre-assembly at the same time as the first pre-assembly.
18 . The method of claim 17 , wherein laminating the second separator/electrode pre-assembly is effected at a temperature less than the melting temperature of the microporous separator.
19 . The method of claim 1 , wherein the adhesive is in the form of a film.
20 . The method of claim 19 , wherein the film is a porous polyethylene.
21 . The method of claim 1 , wherein the adhesive is in the form of a powder.
22 . The method of claim 1 , wherein the powder is a poly(1,1-difluoroethylene-co-polyhexafluoropropylene).
23 . A method of producing an electrode assembly, comprising:
disposing a thermoplastic polymer powder between a first surface of a first electrode and a first surface of a microporous separator to form a separator/electrode pre-assembly; and
adhering the first surface of the first electrode to the first surface of the microporous separator via the thermoplastic polymer powder to form a separator/electrode assembly, wherein the adhesive thermoplastic polymer does not form a solid layer.
24 . The method of claim 23 , wherein at least 50% of the surface area of the electrode and the microporous separator are in contact after adhering.
25 . The method of claim 23 , wherein the melting temperature of the thermoplastic polymer powder is lower than the melting temperature of the microporous separator.
26 . The method of claim 23 , wherein the electrode comprises an active layer comprising a binder.
27 . The method of claim 26 , wherein the melting temperature of the thermoplastic polymer powder is lower than the melting temperature of the binder.
28 . The method of claim 23 , wherein adhering is by laminating the first separator/electrode pre-assembly using roll lamination, flat bed lamination, or double belt press lamination.
29 . An electrode assembly comprising:
a first adhesive layer disposed between and in contact with
a first surface of a first electrode layer having a width W e1 , and
a first surface of a microporous separator layer having a width W m ,
at an aligned edge of the first electrode layer and the microporous separator layer,
wherein the first adhesive has a width W a1 less than ½(W e1 ).
30 . The assembly of claim 29 , further comprising a second adhesive layer disposed between and in contact with the first surface of the first electrode layer and the first surface of the microporous separator layer at a second aligned edge of the first electrode layer and the microporous separator layer, wherein the second edge is opposite the first edge.
31 . The assembly of claim 30 further comprising a second electrode layer, and a second adhesive layer disposed between and in contact with a second surface of the microporous separator layer opposite the first surface, and a first surface of the second electrode layer, at an aligned edge of the second electrode layer and the microporous separator layer.
32 . An electrode assembly comprising:
a thermoplastic polymer adhesively disposed between a first surface of a first electrode and a first surface of a microporous separator, wherein the thermoplastic polymer does not form a solid layer.
33 . The assembly of claim 32 , wherein at least 50% of the surface area of the electrode and the microporous separator are in contact.
34 . An method of manufacture of an electrode assembly, wherein an adhesive thermoplastic polymer powder is combined with the active layer material of the electrode; and the active layer material is then used in the manufacture of an electrode assembly as is known in the art.
35 . An electrode assembly comprising:
a first surface of an active layer of an electrode adhesively in contact with a first surface of a microporous separator, wherein the active layer comprises an adhesive thermoplastic polymer that does not form a solid layer.