Current collector with integrated leak-proofing means, bipolar battery comprising such a collector
The present patent application relates to a device for a lithium electrochemical generator, said device comprising a band ( 100 ) of electrical insulating material including at least one polymer, and at least one metallic layer ( 102 ) which forms a current collector and is deposited on at least one of the two main faces in the central part of the band. The central part ( 100 C) of the band comprises a plurality of holes ( 101 ) emerging on its two opposite main faces, said holes being filled at least partially with a metal that is continuous with each deposited metallic layer. The periphery of the band ( 100 P) is devoid of metallic layer and at least one metallic layer is covered with an electrode of lithium insertion material.
1. A bipolar battery comprising at least two electrochemical cells stacked on one another and at least one device comprising:
a band made of an electrically insulating material comprising at least one polymer; and
at least one metal layer forming a current collector, said metal layer being deposited on each of two main faces in a central portion of the band;
wherein:
the central portion of the band comprises a plurality of holes opening onto two opposite main faces;
the holes are filled at least partially with a metal that is continuous with each deposited metal layer;
the whole periphery of the main faces of the band is devoid of the at least one metal layer and forms a frame of width sufficient to serve as a part of an electrolyte-tight wall in the electrochemical generator;
the at least one metal layer is covered with an electrode made of a lithium insertion material; and
one of the two layers forming the current collector is covered with the anode made of a lithium insertion material of one of the two cells, and the other of the two layers forming the current collector is covered with the cathode made of a lithium insertion material of the other of the two cells, the periphery of the band made of at least one polymer forming a peripheral zone of a wall that is leak-tight to the electrolytes of the two cells that encircles the latter.
2. The bipolar battery as claimed in claim 1 , further comprising at least one device wherein the dimensions of the holes are determined to minimize internal resistance induced by the metal that fills it, and with the other face not covered by an electrode making contact via the holes filled with metal with a terminal current collector.
3. The bipolar battery as claimed in claim 1 , wherein the at least one polymer of the band that is a majority constituent of the band is a polyolefin.
4. The bipolar battery as claimed in claim 1 , wherein the at least one polymer that is a majority constituent of the band is a two-component resin.
5. The bipolar battery as claimed in claim 4 , wherein the resin is an acrylic resin.
6. The bipolar battery as claimed in claim 1 , wherein the holes are of cylindrical section.
7. The bipolar battery as claimed in claim 1 , wherein the holes are of frustoconical section.
8. The bipolar battery as claimed in claim 1 , wherein the diameter of the holes is between 50 and 500 μm.
9. The bipolar battery as claimed in claim 8 , wherein the diameter of the holes is between 50 and 200 μm.
10. The bipolar battery as claimed in claim 1 , wherein the density of the holes is equal to a number between 0.1 and 1/cm 2 of band.
11. The bipolar battery as claimed in claim 10 , wherein the density of the holes is equal to a number between 0.1 and 0.3/cm 2 of band.