Method and apparatus for preparing electrochemical cells

• US 5,746,781 A
• Filed: 04/12/1996
• Issued: 05/05/1998
• Est. Priority Date: 02/22/1996
• Status: Expired due to Fees

• Current Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Original Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Inventors: Gogolin, E. Lawrence, Velasquez, David A., Holmes, Douglas B.
• Primary Examiner(s): KALAFUT, STEPHEN J
• Application Number:
  US08/630,983
• Time in Patent Office: 753 Days
• Field of Search: 29/730, 29/623.3, 29/623.4
• US Class Current: 29/730
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 6/188 Processes of manufacture
• CPC Class Codes: H01M 6/40 Printed batteries , e.g. thin film batteries
• CPC Class Codes: H01M 6/42 Grouping of primary cells into batteries H01M6/40 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/53135 Storage cell or battery

Abstract

A method of fabricating electrochemical cells and batteries wherein the successive anode and cathode layers are separated by a polymeric electrolyte layer having a protruding polymer edge around its perimeter which reduces the likelihood of inadvertent contact between the anode and cathode current collectors is provided. The polymer edge functions as a non-conducting physical barrier positioned between adjacent current collectors. An apparatus for preparing electrochemical cells is also disclosed.

Claims

1. An apparatus for preparing an electrochemical cell, comprising:

a first laminating station that includes means for laminating an anode current collector to at least one anode material film on at least one side of the anode current collector to form an anode precursor at the first laminating station, the anode current collector including an extending anode tab extending past an edge of the anode material film, and the anode material film including a first polymer, an intercalation carbon material, and a first plasticizer;

a second laminating station that includes means for laminating a cathode current collector to at least one cathode material film on at least one side of the cathode current collector to form a cathode precursor at the second laminating station, the cathode current collector including an extending cathode tab extending past an edge of the cathode material film, and the cathode material film including a second polymer, a cathode active material, and a second plasticizer;

an assembling station that includes means for interposing a polymeric layer including a third plasticizer between the anode precursor and the cathode precursor at the assembling station such that the polymeric layer prevents direct contact between the anode current collector and the cathode current collector;

a fusion station that includes means for fusing the polymeric layer to the anode precursor and the cathode precursor at the fusion station to form a bicell battery;

a stacking station that includes means for stacking a plurality of bicell batteries on top of one another at the stacking station to form a stack;

a welding station that includes means for welding a plurality of anode tabs of the stack to one another and to a conductive anode lead, and means for welding a plurality of cathode tabs of the stack to one another and to a conductive cathode lead at the welding station;

an extraction station, downstream from the welding station, that includes means for extracting the first, second, and third plasticizers from the stack at the extraction station;

an installation station, downstream from the extraction station, that includes a stack receptacle which defines a recess that accommodates the stack such that at least portions of the anode lead and the cathode lead extend beyond an outer periphery of the stack receptacle;

a filling station that includes a source of an electrolyte solution including an electrolyte solvent and an inorganic salt to be filled into the receptacle and into the anode precursor, the cathode precursor, and the polymeric layer at the filling station; and

a closing station that includes means for sealing the recess in the stack receptacle such that the portions of the anode lead and the cathode lead are disposed outside of an outer periphery of the closed stack receptacle.

2. The apparatus as set forth in claim 1, wherein the first laminating station includes means for laminating anode material film to both sides of the anode current collector.

3. The apparatus as set forth in claim 1, wherein the second laminating station includes means for laminating cathode material film to both sides of the cathode current collector.

4. The apparatus as set forth in claim 1, further comprising a third laminating station that includes means for laminating a second cathode current collector to at least one second cathode material film on at least one side of the second cathode current collector to form a second cathode precursor at the second laminating station, the second cathode precursor being substantially the same as the first cathode precursor, and the second cathode material film including the second polymer, the cathode active material, and the second plasticizer, wherein, the assembling station further includes means for interposing a second polymeric layer including the third plasticizer between the anode precursor and the second cathode precursor such that the second polymeric layer prevents direct contact between the anode current collector and the second cathode current collector, and, the fusion station further includes means for fusing the second polymeric layer to the anode precursor and the second cathode precursor to form the bicell battery.

5. An apparatus for preparing an electrochemical cell, comprising:

an assembling station that includes means for interposing a polymeric layer including a first plasticizer between (a) an anode precursor, the anode precursor including an anode current collector that is laminated to at least one anode material film on at least one side of the anode current collector, the anode material film including a first polymer, an intercalation carbon material, and a second plasticizer, and (b) a cathode precursor, the cathode precursor including a cathode current collector that is laminated to at least one cathode material film on at least one side of the cathode current collector, the cathode material film including a second polymer, a cathode active material, and a third plasticizer, wherein the polymeric layer prevents direct contact between the anode current collector and the cathode current collector;

an extraction station, downstream from the assembling station, that includes means for extracting the first, second, and third plasticizers from the anode precursor, the cathode precursor, and the polymeric layer, respectively; and

a filling station that includes a source of an electrolyte solution including an electrolyte solvent and an inorganic salt to be filled into the anode precursor, the cathode precursor, and the polymeric layer at the filling station.

6. The apparatus as set forth in claim 5, further comprising a fusion station that includes means for the polymeric layer to the anode precursor and the cathode precursor at the fusion station to form a bicell battery.

7. The apparatus as set forth in claim 6, further comprising a stacking station that includes means for stacking a plurality of bicell batteries being stacked on top of one another at the stacking station to form a stack.

8. The apparatus as set forth in claim 7, wherein the anode current collector includes an anode tab extending beyond an edge of the anode material film, and the cathode current collector includes a cathode tab extending beyond an edge of the cathode material film, the apparatus further comprising a welding station that includes means for welding a plurality of anode tabs of the stack to one another and to a conductive anode lead, and means for welding a plurality of cathode tabs of the stack to one another and to a conductive cathode lead at the welding station.

9. The apparatus as set forth in claim 8, further comprising an installation station, downstream from the extraction station, that includes a stack receptacle which defines a recess that accommodates the stack such that at least portions of the anode lead and the cathode lead extend beyond an outer periphery of the stack receptacle.

10. The apparatus as set forth in claim 9, further comprising a closing station that includes means for sealing the recess in the stack receptacle such that the portions of the anode lead and the cathode lead are disposed outside of an outer periphery of the closed stack receptacle.

11. The apparatus as set forth in claim 7, further comprising an installation station, downstream from the extraction station, that includes a stack receptacle which defines a recess that accommodates the stack.

12. The apparatus as set forth in claim 5, wherein, the assembling station further includes means for interposing a second polymeric layer including the third plasticizer between the anode precursor and a second cathode precursor, the second cathode precursor including a second cathode current collector that is laminated to at least one second cathode material film on at least one side of the second cathode current collector, the second cathode precursor being substantially the same as the first cathode precursor, and the second cathode material film including the second polymer, the cathode active material, and the second plasticizer, such that the second polymeric layer prevents direct contact between the anode current collector and the second cathode current collector, and, wherein the fusion station further includes means for fusing the second polymeric layer to the anode precursor and the second cathode precursor to form the bicell battery.

13. The apparatus as set forth in claim 12, further comprising first, second, and third laminating stations, wherein the first lamination station includes means for laminating the anode material film and the anode current collector, the second laminating station includes means for laminating the first cathode material film and the first cathode current collector, and the third laminating station includes means on laminating the second cathode material film and the second cathode current collector.

14. The apparatus as set forth in claim 13, wherein the first laminating station includes means for laminating the anode material film to both sides of the anode current collector.

15. The apparatus as set forth in claim 13, wherein the second laminating station includes means for laminating the first cathode material film to both sides of the first cathode current collector, and the third laminating station includes means for laminating the second cathode material film to both sides of the second cathode current collector.