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EP-4736264-A1 - VALVE UNIT AND METHOD FOR ELECTROLYTE FILLING OF BATTERY CELL POUCH HOUSING

EP4736264A1EP 4736264 A1EP4736264 A1EP 4736264A1EP-4736264-A1

Abstract

The invention relates to a valve unit (10), which is configured for electrolyte injection, comprising a fluid port (11) for connecting an electrolyte source and comprising a joining portion (12), wherein the joining portion (12) comprises at least two surfaces (21, 22) which are configured for connecting at least one layer of a battery cell housing (101), and comprising at least one fluid channel (13), wherein the at least one fluid channel (13) is protruding through the fluid port (11) and the joining portion (12), characterized in that the fluid channel (13) is repeatedly openable and closeable and the fluid port (11) comprises a locking portion (14) at its outer surface. Furthermore, the invention relates to a manufacturing state battery cell (110) and to a method (50).

Inventors

  • Gräf, Jürgen

Assignees

  • Cellforce Group GmbH

Dates

Publication Date
20260506
Application Date
20240629

Claims (19)

  1. 1. Valve unit (10), which is configured for electrolyte injection, comprising a fluid port (11) for connecting an electrolyte source and comprising a joining portion (12), wherein the joining portion (12) comprises at least two surfaces (21 , 22) which are configured for connecting at least one layer of a battery cell housing (101), and comprising at least one fluid channel (13), wherein the at least one fluid channel (13) is protruding through the fluid port (11) and the joining portion (12), characterized in that the fluid channel (13) is repeatedly openable and closeable and the fluid port (11) comprises a locking portion (14) at its outer surface.
  2. 2. Valve unit according to claim 1 , wherein the fluid port (13) comprises a rotation- symmetric shape around a flow direction (F) through the fluid channel (13), wherein the locking portion (14) is formed as a bulge or as a groove which is arranged at least partially at the outer surface of the fluid port (11).
  3. 3. Valve unit according to claim 1 or 2, wherein the fluid port (11 ), the fluid channel (13) and the joining portion (12) of the valve unit (10) are integrally formed as a one-piece component.
  4. 4. Valve unit according to anyone of the claims 1 to 3, wherein the at least two surfaces (21 , 22) of the joining portion (12) comprise a curved shape.
  5. 5. Valve unit according to anyone of the claims 1 to 4, wherein the at least two surfaces (21 , 22) of the joining portion (12) are formed smoothly or comprise cross ribs.
  6. 6. Valve unit according to anyone of the claims 1 to 5, wherein the joining portion (12) comprise two surfaces (21 , 22) and the two surfaces (21 , 22) comprise cross sections with a bell curve shape with asymptotically shaped tails (23) which are connected with each other at their ends.
  7. 7. Valve unit according to anyone of the claims 1 to 6, wherein the valve unit (10) comprises a valve cap or a valve plug (30) or a melting portion or a bending portion, wherein the fluid channel (13) is repeatedly openable and closeable via the valve cap or the valve plug (30) or the melting portion or the bending portion.
  8. 8. Valve unit according to anyone of the claims 1 to 7, wherein the valve cap or the valve plug (30) comprise at least one axially acting and/or radially acting sealing (31), wherein the at least one sealing (31) is formed integrally with the valve cap or the valve plug (30).
  9. 9. Valve unit according to anyone of the claims 1 to 8, wherein the valve cap or the valve plug (30) is configured to be attached at the fluid port (11) via plugging or screwing in order to prevent fluid leakage.
  10. 10. Valve unit according to claim 9, wherein the valve cap or the valve plug (30) is pluggable inside the fluid channel (13) of the fluid port (11 ) or is screwable into the fluid channel (13) of the fluid port (11) or is screwable onto an outer circumference of the fluid port (11) or is pluggable onto the outer circumference of the fluid port (11).
  11. 11 . Valve unit according to anyone of the claims 1 to 10, wherein the valve cap or the valve plug (30) comprise at least one tool attachment (34), wherein the tool attachment (34) is arranged at at least one side or on top (33) of the valve cap or the valve plug (30).
  12. 12. A manufacturing state battery cell (110) comprising a housing bag (101 with at least one cavity (111 , 112) which incorporates battery cell components (200), especially an anode, a cathode and a separator, and comprising at least one valve unit (10) according to anyone of the preceding claims, wherein at least one fluid channel (13) of the at least one valve unit (10) is forming a fluid connection with the at least one cavity (111 , 112) through a housing sealing (120) and the at least one valve unit (10) is connected with the housing sealing (120) via the joining portion (12).
  13. 13. A manufacturing state battery cell according to claim 12, wherein the manufacturing state battery cell (110) comprises a cell component cavity (111) and at least one buffer cavity (112) for temporally incorporating an electrolyte solution during a manufacturing process (50) of a battery cell (100), wherein the at least one fluid channel (13) of the at least one valve unit (10) protrudes into the at least one buffer cavity (112).
  14. 14. A manufacturing state battery cell according to claim 12 or 13, wherein the at least two surface areas (21 , 22) of the joining portion (12) are connectable to the battery cell housing (101) by welding or soldering or gluing or melting.
  15. 15. A manufacturing state battery cell according to anyone of the claims 12 to 14, wherein the at least two surface areas (21 , 22) of the joining portion (12) of the at least one valve unit (10) are connected to a sealing area of a top edge housing sealing (120) and/or to a sealing area of a cut-off corner (121) of the housing sealing (120), wherein the at least one valve unit (10) extends vertically from the top edge housing sealing (120).
  16. 16. A manufacturing state battery cell according to claim 15, wherein the valve unit (10) extends in an inclined manner from the sealing area of a cut-off corner (121), wherein the inclined valve unit (10) remains below or equal to a height of the top edge housing sealing (120)
  17. 17. A method (50) to manufacture a battery cell (100), wherein a battery cell housing bag (101) comprising one first cavity (111) and one second cavity (112) is formed or provided, wherein battery cell components (200) are positioned inside the first cavity (111), wherein the battery cell housing bag (101) is sealed, wherein at least one valve unit (10) is connected to at least one sealing (120) of the battery cell housing bag (101) and comprises a fluid channel (13) which protrudes into at least the second cavity (112), wherein a vacuum is applied to the first and second cavity (111 , 112) and an electrolyte is introduced into the second cavity (112) via the at least one valve unit (10) at least once, wherein the electrolyte is at least partially soaked by the battery cell components (200), and wherein after complete soaking of the electrolyte by the battery cell components (200) a second sealing (122) is performed between the first and the second cavity (111 , 112) and the second cavity (112) is removed from the first cavity (111) forming a battery cell (100).
  18. 18. Method according to claim 17, wherein the electrolyte is filled at least twice through the valve unit (10) into the second cavity (112), wherein the valve cap or the valve plug (30) is removed for filling of the electrolyte and wherein the valve cap or the valve plug (30) is attached to the fluid port (11) after filling of the electrolyte.
  19. 19. Method according to claim 17 or 18, wherein after complete soaking of the electrolyte by the battery cell components (200) any remaining electrolyte in the second cavity (112) is removed via the at least one valve unit (10) after performing the second sealing (122).

Description

VALVE UNIT AND METHOD FOR ELECTROLYTE FILLING OF BATTERY CELL POUCH HOUSING The present disclosure relates to a valve unit which is configured for electrolyte injection especially during manufacturing of battery cells. The valve unit comprises a fluid port for connecting an electrolyte source and a joining portion, wherein the joining portion comprises at least two surfaces which are configured for connecting at least one layer of a battery cell housing. Moreover, the present disclosure relates to a battery cell housing during a manufacturing of a battery cell and a method for manufacturing battery cells. Lithium-ion batteries are used in different technical fields and provide stored energy to electrical components like electrical motors, displays etc. Especially in electric vehicles and in hybrid electric vehicles such lithium-ion batteries are supplying the vehicle components and the drivetrain with electrical energy. There is constant development of the lithium-ion batteries towards higher capacities. The capacity of the battery may be increased by increasing the surface area of the electrodes. This is achieved by more complex surface structures. During the manufacturing of the lithium-ion batteries battery cell housings are provided and equipped with the usual battery components e.g. anode structure, cathode structure and separator structure. The battery cell housings are then filled with an electrolyte solution which is absorbed by the battery components. This manufacturing step requires multiple refills of the electrolyte solution and may last hours or days depending on the battery cell characteristics. The battery cell housings are usually open to the environment during this waiting time for the full absorption of the electrolyte solution. Thus, for a mass production of such battery cells large storage or manufacturing areas are required which fulfil high standards in order to prevent any contamination, especially of pouch type battery cells. Such areas are complex, expensive to build and maintain and do increase the manufacturing costs of battery cells. An objective of the present disclosure is to provide a valve unit and a method for manufacturing a battery cell which enable filling of battery cell housings over an extended period of time without the risk of contamination or battery housing degradation. This object is achieved by the subject-matter of the independent claims. Further developments of the subject-matter of the independent claims are provided in the sub-claims. According to one aspect of the present disclosure a valve unit is provided. The valve unit is configured for electrolyte injection especially during manufacturing of battery cells. The inventive valve unit comprises a fluid port for connecting an electrolyte source and a joining portion. The joining portion comprises at least two surfaces which are configured for connecting at least one layer of a battery cell housing. At least one fluid channel is provided which is protruding through the fluid port and the joining portion. This fluid channel is configured for injection of fluids through the fluid port such that the fluid channel at the fluid port acts as fluid inlet and the fluid channel at the joining portion acts as a fluid outlet. The fluid channel of the inventive valve unit is repeatedly openable and closeable and the fluid port comprises a locking portion at its outer surface. Via the locking portion a hose or injection adapter may interconnect with the fluid port, especially with the outer surface of the fluid port, in order to provide electrolyte solution infill or in order to generate a vacuum at the fluid channel. Thus, the fluid channel may also act as a fluid outlet if a vacuum or low pressure is generated at the entrance of the fluid port side of the fluid channel. At least one valve unit may be inserted or joined into a battery cell housing during the manufacturing process. Due to the repeatedly openable and closeable fluid channel during the manufacturing of the battery cells the battery cell housings may be opened for filling of electrolyte solution and afterwards the fluid channels may be closed preventing any contamination of the inside cavities and of the battery components inside the battery housing. Thus, the storage area or manufacturing area where the battery cells are stored during the absorption time of the electrolyte is no longer required to fulfil high standards. Thus, the manufacturing sites may be less expensive to build and maintain such that the manufacturing effort and manufacturing costs of battery cells can be reduced. In accordance with an embodiment, the fluid port comprises a rotation-symmetric shape around a flow direction through the fluid channel, wherein the locking portion is formed as a bulge or as a groove which is arranged at least partially at the outer surface of the fluid port. The flow direction through the fluid channel is defined as the axis for the rotation symmetry. Pref