Method and apparatus for vacuum pressing electrochemical cell components

• US 20030145942A1
• Filed: 02/07/2002
• Published: 08/07/2003
• Est. Priority Date: 02/07/2002
• Status: Active Grant

• Current Assignee: Lynntech Incorporated
• Original Assignee: Lynntech Incorporated
• Inventors: Murphy, Oliver J., Andrews, Craig C.
• Granted Patent: US 6,827,811 B2
• Time in Patent Office: Days
• US Class Current: 156/285
• CPC Class Codes: B29C 65/00 Joining or sealing of preformed parts , e.g. welding of plastics materials; Apparatus therefor general aspects of processes or apparatus for joining preformed parts B29C66/00; using porous material formed by internal pressure generated therein for joining preformed parts B29C44/1228, B29C44/326
• CPC Class Codes: B29C 65/482 Drying adhesives, e.g. solvent based adhesives
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/542 by injection
• CPC Class Codes: B29C 65/544 by suction
• CPC Class Codes: B29C 65/546 by gravity, e.g. by pouring
• CPC Class Codes: B29C 65/548 by capillarity
• CPC Class Codes: B29C 66/004 Preventing sticking together, e.g. of some areas of the parts to be joined
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/133 Fin-type joints, the parts to be joined being flexible the parts to be joined being rigid B29C66/1312
• CPC Class Codes: B29C 66/433 Casing-in, i.e. enclosing an element between two sheets by an outlined seam for bookbinding B42C11/06; for packaging B65B; by laminating B32B37/00; enclosing tubular articles between substantially flat elements B29C66/53261
• CPC Class Codes: B29C 66/54 Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/81455 being a fluid inflatable bag or bladder, a diaphragm or a vacuum bag for applying isostatic pressure inflatable element positioned between the joining tool and a backing-up part B29C66/82421
• CPC Class Codes: B29C 66/82423 using vacuum using vacuum directly acting on the parts to be joined B29C66/82661
• CPC Class Codes: B29C 66/8322 Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/83413 cooperating rollers, cylinders or drums
• CPC Class Codes: B29K 2023/06 PE, i.e. polyethylene
• CPC Class Codes: B29K 2077/00 Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29L 2031/3468 Batteries, accumulators or fuel cells battery cases B29L2031/7146
• CPC Class Codes: H01M 8/0258 : characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
• CPC Class Codes: H01M 8/0271 : Sealing or supporting means around electrodes, matrices or membranes
• CPC Class Codes: H01M 8/0284 : Organic resins; Organic polymers
• CPC Class Codes: H01M 8/0286 : Processes for forming seals
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y10T 29/4911 : including sealing
• CPC Class Codes: Y10T 29/49114 : including adhesively bonding
• CPC Class Codes: Y10T 428/13 : Hollow or container type article [e.g., tube, vase, etc.]

Abstract

Assembling electrochemical cell components using a bonding agent comprising aligning components of the electrochemical cell, applying a bonding agent between the components to bond the components together, placing the components within a container that is essentially a pliable bag, and drawing a vacuum within the bag, wherein the bag conforms to the shape of the components from the pressure outside the bag, thereby holding the components securely in place. The vacuum is passively maintained until the adhesive has cured and the components are securely bonded. The bonding agent used to bond the components of the electrochemical cell may be distributed to the bonding surface from distribution channels in the components. To prevent contamination with bonding agent, some areas may be treated to produce regions of preferred adhesive distribution and protected regions. Treatments may include polishing, etching, coating and providing protective grooves between the bonding surfaces and the protected regions.

Claims

1. A method of assembling electrochemical cell components, comprising:

aligning first and second electrochemical cell components;

providing a bonding agent between the first and second electrochemical cell components;

placing the aligned components into a container consisting essentially of a pliable bag; and

drawing a vacuum within the pliable bag, wherein the pliable bag molds to a shape of the aligned components.

2. The method of claim 1, further comprising:

applying pressure to the outside of the vacuum bag, wherein the pressure is selected from hydrostatic pressure and pneumatic pressure.

3. The method of claim 1, further comprising:

placing the sealed vacuum bag containing the components into an oven.

4. The method of claim 1, further comprising:

distributing the bonding agent through one or more closed channels formed between the first and second electrochemical cell components.

5. The method of claim 4, wherein the step of distributing the bonding agent through one or more closed channels farther comprises:

adding the bonding agent into an upward-facing open channel in the bonding surface of the first component;

creating the closed channel when the second component is aligned with the first component; and

inverting the components, wherein the bonding agent flows against the second component by means selected from gravity, capillary action and combinations thereof.

6. The method of claim 5, wherein the open channel contains a plurality of supports disposed in the open channel, the method further comprises:

supporting a section of the second component that covers the open channel;

supporting the open channel, wherein the first and second components do not deform from pressure exerted by the pliable bag.

7. The method of claim 5, wherein the second component has a plurality of supports protruding from a section that covers the open channel, the method further comprising:

supporting a section of the second component that covers the open channel,

supporting the open channel, wherein the first and second components do not deform from pressure exerted by the pliable bag.

8. The method of claim 4, wherein the step of distributing the bonding agent through a channel further comprises:

adding a bonding agent into the closed channel though one or more fill ports, wherein the one or more fill ports are in fluid communication with the closed channel.

9. The method of claim 8, wherein the bonding agent source is a syringe, pump, or other delivery device having a conduit adapted to form a seal with each of the one or more fill ports, the method further comprising:

injecting a bonding agent into the closed channel from the delivery device.

10. The method of claim 4, wherein an overfill reservoir is in fluid communication with the closed channel, the method further comprising:

capturing excess bonding agent flowing from the closed channel into the overfill reservoir.

11. The method of claim 8, wherein the bonding agent source is an open reservoir in one or more of the components, the method further comprises:

pushing the bonding agent into the closed channel with the pliable bag as the vacuum causes the pliable bag to mold to the shape of the reservoir.

12. The method of claim 11, wherein the reservoir contains a spring pushing against the pliable bag, the method further comprises:

maintaining pressure with the spring against a portion of the pliable bag molding to the shape of the reservoir, wherein the spring limits a speed at which the bonding agent is forced from the reservoir.

13. The method of claim 11, wherein an overfill reservoir is in fluid communication with the closed channel, the method further comprising:

capturing excess bonding agent flowing from the closed channel into the overfill reservoir.

14. The method of claim 1, further comprising:

maintaining alignment of the cell components by disposing a bonding agent between the components.

15. The method of claim 1, further comprising:

treating a bonding surface on the first and second electrochemical cell components to enhance flow of the bonding agent; and

treating a non-bonding surface on the first and second electrochemical cell components to inhibit flow of the bonding agent.

16. The method of claim 15, wherein the step of treating a bonding surface comprises a process selected from applying a wetting agent, polishing, etching and combinations thereof.

17. The method of claim 15, wherein step of treating a bonding surface comprises applying a wetting agent selected from detergents, soaps, surfactants, anionic, and cationic surface active compounds.

18. The method of claim 15, wherein the step of treating a non-bonding surface comprises a process selected from roughening, chemically modifying, coating, and combinations thereof.

19. The method of claim 1, further comprising:

providing a feature along an interface between the first and second electrochemical cell components and between a bonding area and a non-bonding area;

retaining and confining excess bonding agent to the region bounded by the features to prevent the bonding agent from reaching the non-bonding area.

20. The method of claim 1, wherein the pliable bag is made of a material selected from polyethylene and a nylon-polyethylene blend.

21. The method of claim 20, wherein the pliable bag has a thickness of between about 2 mils and about 7 mils.

22. The method of claim 1, wherein the step of sealing the bag further comprises melting unsealed edges of the bag together.

23. The method of claim 1, wherein the step of sealing the bag includes hermetically sealing the bag.

24. The method of claim 1, wherein the first and second components are placed in the pliable bag without an alignment frame.

25. The method of claim 1, wherein the vacuum inside the sealed bag is maintained without maintaining a connection to a vacuum source.

26. The method of claim 1, further comprising:

sealing the bag to retain the vacuum within the bag; and

maintaining the vacuum within the bag.

40. The method of claim 1, further comprising:

maintaining the vacuum within the bag until the bonding agent has cured.

41. The method of claim 1, further comprising:

maintaining alignment of the cell components by interlocking one or more feature between the first and second cell components.

42. The method of claim 41, wherein the one or more interlocking feature is a pin.

43. The method of claim 14, wherein the bonding agent is a contact adhesive.

27. A subassembly of electrochemical cell components, comprising:

a first component having a first bonding surface with one or more open channels, wherein the one or more open channels contain a bonding agent; and

a second component having a second bonding surface aligned with the first bonding surface of the first component.

28. The subassembly of claim 27, further comprising:

a plurality of supports disposed within the one or more open channels, wherein the supports prevent the atmospheric or applied external pressure from deforming the first component or the second component along the one or more open channels.

29. The subassembly of claim 27, further comprising:

a plurality of supports extending from the second bonding surface, wherein the supports extend into the one or more open channels when the second bonding surface aligns with the first bonding surface, and wherein the supports prevent the pressure differential from deforming the first component or the second component along the one or more open channels.

30. The subassembly of claim 27, further comprising:

a bonding agent delivery reservoir in fluid communication with the one or more channels; and

a bonding agent disposed in the reservoir.

31. The subassembly of claim 30, wherein the bonding agent reservoir is adapted to expose the bonding agent to externally applied fluid pressure.

32. The subassembly of claim 31, further comprising:

an overflow reservoir in fluid communication with an opposing end of the one or more channels from the bonding agent reservoir.

33. The subassembly of claim 27, further comprising:

opposing bonding surfaces on the first and second electrochemical cell components, wherein the bonding surfaces have been treated to enhance flow of the bonding agent; and

opposing non-bonding surfaces on the first and second electrochemical cell components, wherein the non-bonding surfaces have been treated to inhibit flow of the bonding agent.

34. The subassembly of claim 33, wherein the bonding surfaces have been treated by a process selected from applying a wetting agent, polishing, etching and combinations thereof.

35. The subassembly of claim 33, wherein the non-bonding surfaces have been treated by a process selected from roughening, chemically modifying, coating, and combinations thereof.

36. The subassembly of claim 33, wherein at least one of the non-bonding surfaces is coated with polytetrafluoroethylene (PTFE) or perfluoroalkoxy (PFA).

37. The subassembly of claim 27, further comprising one or more features disposed along an interface between the first and second components to confine adhesive flowing from the bonding surfaces towards a non-bonding surface.

38. The subassembly of claim 27, wherein the bonding surfaces have a plurality of surface features.

39. The subassembly of claim 38, wherein the surface features are micro grooves.

44. The method of claim 27, wherein the bonding agent is a contact adhesive.

45. A method of assembling electrochemical cell components, comprising:

aligning first and second electrochemical cell components;

providing a bonding agent between the first and second electrochemical cell components;

placing the aligned components into a pliable bag,

placing the pliable bag within a vacuum chamber; and

drawing a vacuum on the vacuum chamber.

46. The method of claim 45, further comprising:

sealing the bag to retain the vacuum within the bag; and

removing the sealed bag from the vacuum chamber, wherein the pliable bag molds to a shape of the components.

47. The method of claim 45, further comprising:

maintaining the vacuum inside the sealed bag.

48. The method of claim 46, further comprising:

maintaining the vacuum until the bonding agent has cured.