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EP-4740257-A1 - METHOD AND STATION FOR REMOVING ELECTROLYTE RESIDUES FROM CELLS

EP4740257A1EP 4740257 A1EP4740257 A1EP 4740257A1EP-4740257-A1

Abstract

The invention relates to a method for removing external electrolyte residues from partially processed electrochemical cells, which comprises a step of moving, at least partly along a transit path of partially processed electrochemical cells, a plurality of suction units, wherein a temporary coupling is performed of at least one of the suction units with a respective cell or with a transport puck for that cell, so as to keep the suction unit substantially integral with the cell or with the puck along at least part of the transit path; and, during such temporary coupling, any electrolyte residues present on an external surface of the head portion of the cell are aspirated.

Inventors

  • FURLOTTI, FILIPPO

Assignees

  • I.M.A. Industria Macchine Automatiche S.p.A.

Dates

Publication Date
20260513
Application Date
20240702

Claims (20)

  1. 1. A method for removing external electrolyte residues from partially processed cells originating from a station for filling with electrolyte for battery production lines, said method comprising a step of conveying said cells along a transit path (T), each one of said cells comprising a container (C) having a head portion (38) provided with an inlet (30) for access to an internal volume of the container (C), said internal volume containing a predetermined amount of said electrolyte, said method being characterized in that it comprises a step of moving, at least partly along said transit path, a plurality of suction units (2a, 2a', 2b), and in that it comprises, during said movement step, the steps of: - temporary coupling of at least one of said suction units (2a, 2a', 2b) with a respective one of said cells or with a transport puck of said respective cell, so as to keep said suction unit (2a, 2a', 2b) substantially integral with said cell or said puck along at least part of said transit path; and - during said temporary coupling, suction of possible residues of said electrolyte present on an external surface of said head portion of the container (C).
  2. 2. The method according to the preceding claim, wherein said suction unit comprises one or both of a first suction unit (2a, 2a'), configured for the suction of said possible residues of said electrolyte centrally to said head portion of the container (C), and a second suction unit (2b), configured for the suction of said possible residues of said electrolyte peripherally to said head portion of the container (C).
  3. 3. The method according to the preceding claim, wherein said first suction unit (2a) comprises a main body (5) and a suction plunger (7) which is slideably coupled to said main body and functionally communicates with suction means, said temporary coupling step comprising the steps of: - relative approach of said main body and said cell; - engagement of said main body with said head portion of the container (C) or with said puck; - sliding of said suction plunger with respect to said main body (5) and toward said external surface of the head portion of the container (C').
  4. 4. The method according to the preceding claim, wherein said main body (5) is substantially bell-shaped, with an open base configured to engage said head portion or said puck so as to center said first suction unit (2a) with respect to said container (C), said suction plunger (7) being able to slide in said main body (5) along a direction that is substantially coaxial to said main body (5).
  5. 5. The method according to claim 2, wherein said first suction unit (2a') comprises a first suction body (44) which functionally communicates with suction means, said temporary coupling step comprising the steps of: - relative approach of said first suction body and of said container (C); - engagement of said first suction body (44) with a central surface (37) of the head portion of the container (C).
  6. 6. The method according to the preceding claim, wherein said first suction body (44) comprises a head (45) provided with a blind central portion (46) adapted to temporarily plug said inlet (30) during the suction.
  7. 7. The method according to one or more of claims 2-6, wherein said second suction unit (2b) comprises a second suction body (41) which functionally communicates with suction means, said temporary coupling step comprising the steps of: - relative approach of said second suction body and of said container (C); - engagement of said second suction body (41) with the peripheral region of the head portion of the container (C).
  8. 8. The method according to the preceding claim, wherein said second suction body (41) has a substantially toroidal shape adapted to be passed through by a sealing plug (20) which protrudes from the inlet (30) and to position itself on the rim of the head portion (38) of the container (C).
  9. 9. A method for manufacturing batteries, which comprises an electrode production step (301), a cell assembly step (302) and a step for finishing said cells (303), said cell assembly step comprising a step of filling containers with said electrolyte at a filling station, characterized in that it comprises, after said filling step, the method for removing residues according to one or more of the preceding claims.
  10. 10. The method according to the preceding claim, wherein said cell assembly step comprises a step of sealing said containers (C) which is performed after a first suction step, which is performed by means of said first suction unit (2a, 2a'), and/or before a second suction step, which is performed by means of said second suction unit (2b).
  11. 11. The method according to one or more of the preceding claims, wherein said method for removing residues is performed inside a dry room (100).
  12. 12. The method according to one of claims 9-11, wherein a plurality of said suction units (2a, 2a', 2b) are recirculated along a closed trajectory (SI, S2), which overlaps that part of said transit path (T) along which said steps of temporary coupling and suction are performed.
  13. 13. A suction station (328a, 328b) for removing external electrolyte residues from partially processed cells following their filling with an electrolyte, which comprises a transit path for said cells, or for pucks adapted to each contain at least a respective one of said cells, said suction station being characterized in that it comprises at least one suction unit (2a, 2a', 2b) which can move along a portion of said transit path and toward/away from said transit path in order to temporarily couple itself to respective cells, or with the respective pucks, conveyed along said transit path.
  14. 14. The suction station (328a, 328b) according to the preceding claim, comprising means for moving said suction units (2a, 2a', 2b) with a continuous motion along a closed circular trajectory (SI, S2), which overlaps with said part of the transit path (T) of the cells.
  15. 15. The suction station (328a, 328b) according to claim 13 or 14, comprising a carousel or starwheel (150a, 150b), which can rotate with a continuous motion about a rotation axis and is adapted to convey or entrain said cells or said pucks along said part of the transit path while keeping said cells or said pucks spaced apart at a constant pitch about said axis of rotation, said suction units (2a, 2a', 2b) being arranged, with said constant pitch about said axis of rotation, on said carousel or starwheel so as to be superimposed on said cells or said pucks.
  16. 16. The suction station (328a) according to one or more of the preceding claims, wherein said at least one suction unit comprises a first suction unit (2a) which comprises a main body (5) and a suction plunger (7) which is slideably coupled to said main body and functionally communicates with suction means.
  17. 17. The suction station (328a) according to the preceding claim, wherein said main body (5) is substantially bell-shaped, with an open base configured to engage a head portion of the cell or a cell transport puck so as to center said first suction unit (2a) with respect to said cell, said suction plunger (7) being able to slide in said main body (5) along a direction that is substantially coaxial to said main body (5).
  18. 18. The suction station (328a) according to claim 16 or 17, wherein said suction plunger (7) comprises a head (8) having a blind central portion (9), so as to plug a filling inlet (30) of the cell when said suction plunger is placed in a position closer to said part of the transit path, and one or more lateral suction channels (70) which communicate with said suction means and which come out at a position that is adjacent to said blind central portion (9).
  19. 19. The suction station (328a) according to one or more of claims 16 to 18, wherein said suction plunger (7) is coupled to said main body (5) by means of a form-fit coupling adapted to allow said sliding and possibly an axial rotation of said suction plunger with respect to said main body.
  20. 20. The suction station (328a) according to one or more of claims 13- 15, wherein said at least one suction unit comprises a first suction unit (2a') having a first suction body (44), which functionally communicates with suction means and has a substantially cylindrical shape with a cross-section adapted for coupling to a head portion (38) of the cell (C).

Description

METHOD AND STATION FOR REMOVING ELECTROLYTE RESIDUES FROM CELLS The present invention relates to a method and a station for removing any external electrolyte residues from partially processed cells (preferably electrochemical cells), as well as a battery production method and production line that respectively comprise such a method and such a station. Although the invention is particularly adapted to the production of batteries (primary or secondary) of the electrochemical cylindrical (single or multiple) cell type, for example lithium ion batteries, the invention is in any case also adapted to the production of other electrolytic or electrochemical cells or other forms of cell packaging, for example prismatic cells or pouch cells. Battery production lines (for single-cell or multiple-cell batteries), for example for producing lithium ion batteries, require that at least some of the processing steps take place in a "dry room", i.e. a sealed and ultra-dry room, i.e. with an extremely low rate of controlled humidity (typically of the order of 1% by volume) and with a dew point that can be lower than -40°C. This occurs, in particular, in those cases in which the materials of the electrodes and/or the electrolytes that fill the battery are sensitive to humidity, i.e. they react with water. Typically, the steps of filling an electrochemical cell during manufacture entail loading an electrolyte (typically in the form of a liquid or gel) into the container into which electrodes have been previously inserted, through a filling inlet located in the upper part, or head, of the cell. Subsequently, still in the dry room, there is a step of sealing the battery so as to plug it, so isolating the internal volume of the battery, occupied by the electrolyte, from the outside environment. This sealing can be temporary and be obtained by inserting a temporary plug or pin which is then removed in a subsequent degassing station. This conventional method for making batteries is not devoid of drawbacks, among which is the fact that, during the steps of filling, electrolyte residue can be accidentally deposited around the filling inlet of the electrochemical cell and, considering the corrosive and inflammable properties of the electrolyte, can compromise the hermetic seal of the battery, its operation and/or the safety of the operations following the sealing, whether temporary or final. In more detail, corrosion can imply the deterioration of the external surface of the battery, at the sealing plug, so altering the geometry of the inlet and allowing the passage of gas - and therefore of air - from the outside environment to the internal volume of the battery and vice versa. Furthermore, considering the toxicity of the electrolytes used in batteries, any external residues can damage the persons handling the batteries outside of the production line, for example if such electrolyte residues should come into contact with their eyes and/or their skin. There is also a risk that the electrochemical cell may catch fire if the electrolytic residue should come into contact with the environmental humidity outside the dry room. The aim of the present invention is to provide a battery production method and production line, as well as a method and a station for removing any external electrolyte residues from electrochemical cells, particularly for said production method and said production line, that are capable of improving the prior art in one or more of the above-mentioned aspects. Within this aim, an object of the invention is to provide electrochemical cells or batteries that are free from external residues of the electrolyte with which they are filled. Another object of the invention is to eliminate or in any case reduce the risks to health of the persons who work on a battery production line in which the batteries are filled with electrolytes that are potentially harmful to health. Another object of the invention is to enable the removal of external electrolyte residues from electrochemical cells while they are transiting with continuous motion along the production line. Another object of the invention is to enable the removal of external electrolyte residues while not interfering with any temporary sealing plugs which protrude from the electrolyte filling inlet of the cell. Furthermore, the present invention sets out to overcome the drawbacks of the prior art in a manner that is alternative to any existing solutions. Another object of the invention is to provide a battery production method and production line, as well as a method and station for removing any external electrolyte residues from electrochemical cells, particularly for said production method and line, which are highly reliable, easy to implement and at low cost. This aim and these and other objects which will become better apparent hereinafter are achieved by a method according to claim 1, optionally provided with one or more of the characteristics of the dependent clai