Multilayer structure for a battery encasement
The present invention is related to a battery module packaging comprising a multilayer structure 1 , said structure comprising an inner polymer layer 2 , an outer polymer layer 4 and an aluminum foil 5 sandwiched between the inner polymer layer 2 and the outer polymer layer 4 , or an inner polymer layer 2 , an outer polymer layer 4 , an aluminum foil 5 sandwiched between the inner polymer layer 2 and the outer polymer layer 4 and an intermediary layer 3 sandwiched between aluminum foil 5 and inner polymer layer 2 . In use, the inner polymer layer 2 is in direct contact with the cell part of the battery and the outer polymer layer 4 is in contact with a hardware element of the battery.
1 . Battery module packaging comprising a flexible multilayer structure said structure comprising:
an inner polymer layer, an outer polymer layer and an aluminum foil sandwiched between the inner polymer layer and the outer polymer layer, or
an inner polymer layer, an outer polymer layer, and an aluminum foil sandwiched between the inner polymer layer and the outer polymer layer and an intermediary polymer layer sandwiched between aluminum foil and the inner polymer layer
wherein:
inner polymer layer comprises a chromium based protective layer on one side, facing the aluminum foil or intermediary polymer layer; and/or
the aluminum foil comprises a chromium based protective layer on one side, facing the inner polymer layer or the intermediary polymer layer; and/or
the intermediary polymer layer comprises a chromium based protective layer on at least one of its sides, facing either the aluminum foil and/or the inner polymer layer; and
wherein:
the chromium based protective layer is a metallic chromium layer comprising trivalent chromium, wherein the metallic chromium layer comprises 0.5% by weight to less than 50 by weight of trivalent chromium;
a modified polyolefin tie layer is deposited between the aluminum foil and the inner polymer layer or between the aluminum foil and the intermediary polymer layer and between the inner and intermediary polymer layers and, wherein at least one of said aluminum foil and one of said inner and intermediary polymer layers comprises the chromium based protective layer; and
wherein in use
the inner polymer layer is in direct contact with a cell part of a battery; and
the outer polymer layer is in contact with a hardware element of the battery.
2 . The battery module packaging according to claim 1 wherein flexible multilayer structure comprises an inner polymer layer, an outer polymer layer and an aluminum foil sandwiched between the inner polymer layer and the outer polymer layer, wherein:
inner polymer layer comprises a chromium based protective layer on one side, facing the aluminum foil; or
aluminum foil comprises a chromium based protective layer on one side, facing inner polymer layer.
3 . The battery module packaging according to claim 1 wherein flexible multilayer structure comprises an inner polymer layer, an outer polymer layer, an aluminum foil sandwiched between the inner polymer layer and the outer polymer layer and an intermediary polymer layer sandwiched between aluminum foil and inner polymer layer, wherein:
inner polymer layer comprises a chromium based protective layer on one side, facing the intermediary polymer layer; and/or
aluminum foil comprises a chromium based protective layer on one side, facing intermediary polymer layer; and/or
intermediary polymer layer comprises a chromium based protective layer on at least one of its sides, facing aluminum foil and/or inner polymer layer.
4 . The battery module packaging according to claim 1 wherein a modified polyolefin tie layer of flexible multilayer structure is deposited between:
[chromium based protective layer side of the aluminum foil and intermediary polymer layer] and [intermediary polymer layer and inner polymer layer]; or
[aluminum foil and chromium based protective layer side of intermediary polymer layer] and [intermediary polymer layer and inner polymer layer]; or
[aluminum foil and intermediary polymer layer] and [chromium based protective layer side of intermediary polymer layer and inner polymer layer]; or
[aluminum foil and intermediary polymer layer] and [chromium based protective layer of inner polymer layer and intermediary polymer layer]; or
[aluminum foil and chromium based protective layer side of intermediary polymer layer] and [inner polymer layer and chromium based protective layer side of intermediary polymer layer]; or
[chromium based protective layer of aluminum foil and intermediary polymer layer] and [chromium based protective layer of intermediary polymer layer and inner polymer layer]; or
[aluminum foil and chromium based protective layer side of intermediary polymer layer] and [intermediary polymer layer and chromium based protective layer side of inner polymer layer]; or
[chromium based protective layer side of aluminum foil and intermediary polymer layer] and [intermediary polymer layer and chromium based protective layer side of inner polymer layer];
of flexible multilayer structure.
5 . The battery module packaging according to claim 1 , wherein modified polyolefin tie layer of flexible multilayer structure comprises a C2-C8 olefin copolymer comprising one or more monomers selected from the group consisting of maleic anhydride, vinyl acetate, vinyl alcohol, (meth)acrylic acid and alkyl (meth)acrylate.
6 . The battery module packaging according to claim 1 , wherein modified polyolefin tie layer of flexible multilayer structure comprises an anhydride modified polyolefin tie layer.
7 . The battery module packaging according to claim 1 , wherein modified polyolefin tie layer of flexible multilayer structure comprises maleic anhydride polyethylene or maleic anhydride polypropylene or a blend thereof.
8 . The battery module packaging according to claim 1 , wherein modified polyolefin tie layer of flexible multilayer structure is characterized by a layer thickness between 1 and 30 μm.
9 . The battery module packaging according to claim 1 , wherein the chromium based protective layer of flexible multilayer structure is characterized by a thickness comprised between 1 nm and 5 μm.
10 . The battery module packaging according to claim 9 wherein the chromium based protective layer of flexible multilayer structure is characterized by a thickness comprised between 1 nm and 150 nm.
11 . The battery module packaging according to claim 1 , wherein the inner polymer layer of the flexible multilayer structure comprises one or more polymer layers selected from the group consisting of polyethylene, polypropylene, cyclic olefin copolymer, poly(vinylalcohol-co-ethylene) and poly(ethylene-co-chlorotrifluoro-ethylene).
12 . The battery module packaging according to claim 1 , wherein the inner polymer layer of the flexible multilayer structure is characterized by a thickness comprised between 10 and 100 μm.
13 . The battery module packaging according to claim 1 , wherein the outer polymer layer and the intermediary layer of the flexible multilayer structure independently comprise one or more layers selected from the group consisting of polyester, polyamide and polyolefin.
14 . The battery module packaging according to claim 1 , wherein the outer polymer layer and the intermediary polymer layer of the flexible multilayer structure are characterized by a thickness comprised between 4 and 30 μm.
15 . The battery module packaging according to claim 1 wherein the thickness of aluminum foil of the multilayer structure is comprised between 6 and 80 μm.
16 . Battery module comprising the battery module packaging according to claim 1 , being a lithium battery module.