Current collector having a built-in sealing means, bipolar battery including such a collector, method for manufacturing such a battery

Patent metadata

Field	Value
Publication number	US-10497941-B2
Application number	US-201314432688-A
Country	US
Kind code	B2
Filing date	Sep 30, 2013
Priority date	Oct 1, 2012
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

The invention relates to a device for a lithium electrochemical generator, having an elongate shape along a longitudinal axis (X), comprising a strip comprising a current collector central portion that is at least partially electrically conductive, in which at least one of the two main surfaces is covered with an electrode consisting of a lithium insertion material, and at least two side peripheral portions connected to the central portion and extending transversely to the longitudinal axis, the side peripheral portions being made of an electrically insulating material comprising at least one polymer, the insulating material of at least one of the two side portions being resiliently or plastically deformable, the dimensions of the latter also being determined such as to allow the deformation thereof without breaking during the winding of the strip about a winding axis, which is transverse to the axis (X) and adjacent to the other one of the two side peripheral portions. The invention relates to the method for manufacturing a related bipolar battery.

First claim

The invention claimed is:

1. A bipolar battery comprising at least two electrochemical cells coiled on one another and at least one device for a lithium-ion electrochemical generator, of elongate shape along a longitudinal axis, comprising a band comprising a central portion, at least part of which is electrically conductive, forming a current collector having two main faces, at least one of the two main faces of which is covered with an electrode made of a lithium-ion insertion material, and at least two lateral peripheral portions connected to the central portion and extending primarily transversely to the longitudinal axis, the lateral peripheral portions being made of an electrically insulating material comprising at least one polymer, the insulating material of at least one of the two lateral peripheral portions being able to be elastically or plastically deformed, the dimensions of said one of the two lateral peripheral portions furthermore being defined to allow its deformation without rupture during a coiling of the band around a coiling axis that is transverse to the longitudinal axis and in proximity to the other of the two lateral peripheral portions, said one of the two lateral peripheral portions furthermore overshooting the central portion in a direction parallel to the longitudinal axis, each main face of the electrically conductive part being covered with an electrode made of a lithium-ion insertion material, in which the two lateral peripheral portions made of electrically insulating material form a peripheral zone of a wall leak-tight to the electrolytes of the two cells, which encircles said two cells.

2. The bipolar battery as claimed in claim 1 , the majority polymer of the insulating material of the at least one device that is able to be deformed being chosen from a polyolefin, a nitrile rubber (NBR) and a styrene butadiene rubber (SBR).

3. The bipolary battery as claimed in claim 2 , the polyolefin being chosen from a polyethylene (PE), a polypropylene (PP), a polyimide and a polyetheretherketone (PEEK).

4. The bipolar battery as claimed in claim 1 , the electrically conductive part of the at least one device comprising at least one metal sheet, the lateral peripheral portions made of insulating material being sealed to said metal sheet.

5. The bipolar battery as claimed in claim 4 , the metal sheet being sealed to a single frame made of an electrically insulating material that is able to be deformed, said frame completely encircling the metal sheet.

6. The bipolar battery as claimed in claim 4 , the metal sheet being sealed to a frame made of an electrically insulating material having a U-shape as seen from in front, encircling the metal sheet except for the lateral peripheral portion dimensioned for its deformation, and to said lateral peripheral portion made of material able to be deformed, respectively.

7. The bipolar battery as claimed in claim 1 , the band of the at least once device being made of an electrically insulating material that is able to be deformed, the electrically conductive part consisting of electrically conductive particles embedded in the band.

8. The bipolar battery as claimed in claim 7 , the band of the at least one device being mechanically reinforced at its periphery, except for the lateral peripheral portion dimensioned for its deformation, by non-conductive electrical particles.

9. A process for producing a bipolar battery comprising at least two electrochemical cells coiled on one another, comprising the following steps:
a/ producing two devices for a lithium-ion electrochemical generator, of elongate shape along a longitudinal axis, comprising a band comprising a central portion, at least part of which is electrically conductive, forming a current collector having two main faces, at least one of the two main faces of which is covered with an electrode made of a lithium-ion insertion material, and at least two lateral peripheral portions connected to the central portion and extending primarily transversely to the longitudinal axis, the lateral peripheral portions being made of an electrically insulating material comprising at least one polymer, the insulating material of at least one of the two lateral peripheral portions being able to be elastically or plastically deformed, the dimensions of said one of the two lateral peripheral portions furthermore being defined to allow its deformation without rupture during a coiling of the band around a coiling axis that is transverse to the longitudinal axis and in proximity to the other of the two lateral peripheral portions, said one of the two lateral peripheral portions furthermore overshooting the central portion in a direction parallel to the longitudinal axis, each main face of the electrically conductive part being covered with an electrode made of a lithium-ion insertion material,
so that:
at least one of the two faces of the electrically conductive part of one of the devices is covered with an anode made of a lithium-ion insertion material; and
at least one of the two faces of the electrically conductive part of the other of the devices is covered with a cathode made of a lithium-ion insertion material;

b/ stacking the two devices with insertion of a first separator, wherein each face which is not facing another face defines an end of the stack; the stacking with insertion being carried out so that an anode of one of the two devices is facing a cathode of the other device, said anode and cathode being separated by the first separator;
c/ sealing only between the lateral peripheral portions of the bands of the two devices stacked one against the other, thus defining two sealed portions of the stack;
d/ fastening one of the sealed portions of the stack to a coiling core so that its axis forms a coiling axis that is transverse to the longitudinal axis of the bands; and
e/ coiling the stack in the direction of the longitudinal axis about the coiling axis, the sealed portion of the stack which is not fastened to the core being held.

10. The process as claimed in claim 9 , in which each of both ends of the stack is covered with an electrode and when the two electrodes at the ends of the stack and coiled one against the other are of the same polarity, a step c1/ of covering the stack with a film made of an electrically insulating material is carried out before step d/.

11. The process as claimed in claim 9 , in which each of both ends of the stack is covered with an electrode and when the two electrodes at the ends of the stack and coiled one against the other are of opposite polarity, the following steps are carried out before step d/:
c2/ a second separator is placed on the cathode or anode made of a lithium-ion insertion material at the end of the stack; and
c3/ the second separator is mechanically held on the stack.

12. The process as claimed in claim 9 , in which once step e/ has been carried out, the following subsequent steps are carried out:
f/ packaging of the coil using a packaging film made of an electrically insulating material in order to maintain mechanically said coil in the shape of a cylinder;
g/ sealing the lower portion of the cylinder corresponding to one of the longitudinal peripheral portions of the bands;
h/ inserting the cylinder with the sealed lower portion into a rigid container of complementary cylindrical shape, the rigid container forming the packaging of the battery;
i/ impregnating the separators with a liquid electrolyte introduced into the container; and
j/ sealing the upper portion of the cylinder corresponding to the other of the longitudinal peripheral portions of the bands.

13. The process as claimed in claim 9 , each of

Assignees

• Commissariat Energie Atomique

Inventors

• Chami Marianne
• Reynier Yvan

Classifications

• H01M10/044

  with bipolar electrodes · CPC title

• Y10T29/4911

  including sealing · CPC title

• H01M10/0431

  Cells with wound or folded electrodes (H01M10/045 takes precedence) · CPC title

• H01M4/139

  Processes of manufacture · CPC title

• H01M4/75

  Wires, rods or strips · CPC title