Battery interconnects
Provided are interconnects for interconnecting a set of battery cells, assemblies comprising these interconnects, methods of forming such interconnects, and methods of forming such assemblies. An interconnect includes a conductor comprising two portions electrically isolated from each other. At least one portion may include two contacts for connecting to battery cells and a fuse forming an electrical connection between these two contacts. The interconnect may also include an insulator adhered to the conductor and mechanically supporting the two portions of the conductor. The insulator may include an opening such that the fuse overlaps with this opening, and the opening does not interfere with the operation of the fuse. In some embodiments, the fuse may not directly interface with any other structures. Furthermore, the interconnect may include a temporary substrate adhered to the insulator such that the insulator is disposed between the temporary substrate and the conductor.
1. An interconnect circuit for interconnecting battery cells, the interconnect circuit comprising:
a conductive layer comprising conductive layer islands, each comprising a contact pad, a fusible link, and a remaining portion, wherein the contact pad is partially surrounded and separated from the remaining portion by a conductive layer channel; and
an insulating layer laminated to at least a portion of the conductive layer, wherein:
the insulating layer mechanically supports and maintains registration of the conductive layer islands relative to each other, and
the fusible link forms an electrical connection between the contact pad and the remaining portion,
the fusible link is configured to control a current flowing between the contact pad and the remaining portion and to break when the current exceeds a set threshold, and
at least a portion of the fusible link is freestanding and is not attached to the insulating layer,
the insulating layer comprises an insulating layer opening aligned and overlapping with the contact pad such that the contact pad is freestanding and is not attached to the insulating layer, and
the fusible link overlaps with the insulating layer opening.
2. The interconnect circuit of claim 1 , wherein the fusible link is monolithic with the contact pad and the remaining portion.
3. The interconnect circuit of claim 1 , wherein the conductive layer comprises aluminum.
4. The interconnect circuit of claim 1 , wherein the conductive layer has a thickness of between 25 micrometers to 2 millimeters.
5. The interconnect circuit of claim 1 , wherein the insulating layer comprises a material selected from the group polyimide (PI), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET).
6. The interconnect circuit of claim 1 , wherein the insulating layer has a thickness of 10 micrometers to 125 micrometers.
7. The interconnect circuit of claim 1 , wherein the insulating layer comprises an adhesive sublayer, adhered to the conductive layer.
8. The interconnect circuit of claim 7 , wherein the insulating layer further comprises an additional adhesive sublayer facing away from the conductive layer.
9. The battery pack assembly of claim 1 , wherein:
the interconnect circuit comprises a second insulating layer such that the conductive layer is positioned between the insulating layer and the second insulating layer,
the second insulating layer comprises a second insulating layer opening aligned and overlapping with the contact pad such that the contact pad is freestanding and is not attached to the second insulating layer, and
the fusible link overlaps with the second insulating layer opening.
10. The interconnect circuit of claim 1 , further comprising voltage monitoring traces, each electrically coupled to one of the conductive layer islands.
11. The interconnect circuit of claim 10 , wherein each of the voltage monitoring traces is monolithic with one of the conductive layer islands.
12. The interconnect circuit of claim 1 , wherein:
the fusible link comprises a first surface, a second surface opposite of the first surface, and sidewalls extending between the first surface and the second surface, and
the first surface forms an angle with each of the sidewalls of between 75° and 105°.
13. The interconnect circuit of claim 1 , further comprising:
a second insulating layer such that the conductive layer is positioned between the insulating layer and the second insulating layer,
the second insulating layer comprises a second insulating layer opening aligned and overlapping with the contact pad such that the contact pad is freestanding and is not attached to the second insulating layer, and
the fusible link overlaps with the second insulating layer opening.
14. An interconnect circuit for interconnecting battery cells, the interconnect circuit comprising:
a conductive layer comprising a plurality of contact pads, a plurality of fusible links, and a remaining portion, wherein each of the plurality of contact pads is partially surrounded and separated from the remaining portion by one of a plurality of conductive layer channels;
an insulating layer laminated to at least a portion of the conductive layer; and
a substrate, wherein:
the conductive layer is positioned between the insulating layer and the substrate,
the insulating layer mechanically supports portions of the conductive layer, and
each of the plurality of fusible links forms an electrical connection between one of the plurality of contact pads and the remaining portion,
each of the plurality of fusible links is configured to control a current flowing between the one of the plurality of contact pads and the remaining portion and to break when the current exceeds a set threshold,
at least a portion of the fusible link overlaps with the substrate,
at least a portion of each of the plurality of fusible links is not attached to the insulating layer,
the insulating layer comprises a plurality of insulating layer openings, each being aligned and overlapping with a corresponding one of the plurality of contact pads such that each of the plurality of contact pads is freestanding and is not attached to the insulating layer, and
each of the plurality of fusible links overlaps with a corresponding one of the plurality of insulating layer openings.
15. The interconnect circuit of claim 14 , wherein the substrate is laminated to at least a portion of each of the plurality of contact pads.
16. The interconnect circuit of claim 14 , further comprising:
a second insulating layer such that the conductive layer is positioned between the insulating layer and the second insulating layer,
the second insulating layer is positioned between the substrate and the insulating layer,
the second insulating layer comprises a second insulating layer opening aligned and overlapping with the contact pad such that the contact pad is freestanding and is not attached to the second insulating layer.
17. The interconnect circuit of claim 16 , wherein at least a portion of the fusible link overlaps with the second insulating layer opening.
18. The interconnect circuit of claim 16 , wherein at least a portion of the fusible link is freestanding and is not attached to the second insulating layer.
19. A battery pack assembly comprising:
battery cells, each comprising a battery terminal; and
an interconnect circuit comprising a conductive layer and an insulating layer, wherein:
the insulating layer is laminated to at least a portion of the conductive layer and is positioned between at least portions of the conductive layer and the battery cells,
the conductive layer comprises conductive layer islands, each comprising a contact pad, a fusible link, and a remaining portion,
the insulating layer mechanically supports and maintains registration of the conductive layer islands relative to each other,
the contact pad is partially surrounded and separated from the remaining portion by a conductive layer channel,
the contact pad is connected to the battery terminal of at least of the battery cells,
the fusible link forms an electrical connection between the contact pad and the remaining portion,
the fusible link is configured to control a current flowing between the contact pad and the remaining portion and to break when the current exceeds a set threshold, and
at least a portion of the fusible link is freestanding and is not attached to the insulating layer,
the insulating layer comprises an insulating layer opening aligned and overlapping with the contact pad such that the contact pad is freestanding and is not attached to the insulating layer, and
the fusible link overlaps with the insulating layer opening.
20. The battery pack assembly of claim 19 , wherein the battery cells are cylindrical battery cells.
21. The battery pack assembly of claim 19 , wherein the contact pad is welded to the battery terminal of at least of the battery cells.
22. The battery pack assembly of claim 19 , wherein the insulating layer is in contact with the battery cells.