Prismatic battery cell and associated positioning method

Abstract

The invention relates to a prismatic electric battery cell (1) comprising a primary current collector (30) comprising at least two lateral legs (41); each lateral leg (41) comprising a main section (45) and a positioning blade (43) integral with the main section (45), the positioning blade (43) and the main section (45) being configured to prevent a translational movement between them of a current collector tab (55) of an electrode of the battery cell (1). The invention also relates to a positioning method (P1) and to a manufacturing method (P2) for a battery cell (1).

Description

[0001] DESCRIPTION

[0002] TITLE: Current collector, prismatic battery cell and associated positioning method

[0003] Technical field of the invention

[0004] The present invention relates to the field of prismatic electric battery cells.

[0005] State of the art

[0006] In the field of secondary batteries, and particularly batteries for electric vehicles, prismatic battery cells are commonly manufactured. Their shape allows them to be easily stacked side by side, which is especially advantageous for building an electric vehicle battery. Generally, such battery cells consist of two electrodes: an anode and a cathode, which are in the form of sheets. These electrodes are then stacked and compressed to form one or more electrode stacks that make up the prismatic battery cell. Between the anode and the cathode, a separator is positioned to prevent a short circuit between the two electrodes. The electrode stack is then inserted into a casing that serves to protect the stack and to allow the insertion of an electrolyte, which facilitates ion transport between the two electrodes.

[0007] To maximize battery cell capacity, it is known to create two stacks of electrodes designed to be inserted inside the same battery cell casing. Furthermore, the prismatic battery cell cover includes two terminals used for interconnection with other battery cells.

[0008] To channel the current produced by the electrode stacks to the terminals of the cover, it is known in the prior art to use a current collector for each terminal. These current collectors are electrically connected to each electrode. They must ensure efficient and reliable collection of the current produced by the electrodes. Furthermore, once the current collection is achieved, it is necessary to ensure that the assembly formed by the electrodes and current collectors is securely fixed inside the casing to limit any movement of the stack relative to the casing under normal battery operating conditions.

[0009] Therefore, to ensure optimal performance of a prismatic battery cell, precise positioning of the stacks relative to the current collectors and the casing is essential. This positioning is a critical step in the positioning process, particularly for large-scale production.

[0010] It is indeed necessary to ensure that the electrode stacks are inserted into the battery cell casing without coming into contact with the casing walls, as this could damage them. Furthermore, once inserted, the stacks must not be too close to the battery cell cover, as this would prevent the electrolyte from being injected at the desired flow rate. Therefore, improper positioning of the stacks within the battery cell casing can lead to the disposal of numerous battery cells.

[0011] There is therefore a need to find a prismatic battery cell in which the current is efficiently collected at the electrodes and routed to the cover, and in which the positioning of the electrode stacks in the casing is reliable and simply achieved.

[0012] Object of the invention

[0013] The present invention aims to provide a solution that addresses all or part of the aforementioned problems.

[0014] This goal can be achieved through the implementation of a primary current collector for a prismatic electric battery cell comprising: an upper section intended to be electrically connected to a terminal of the battery cell; and a lateral section, forming a non-zero angle with the upper section and intended to be electrically connected to current collection tabs of an electrode of the battery cell, the lateral section comprising at least two lateral tabs each extending in a lateral direction between a proximal end fixed to the upper section, and a free distal end;each lateral leg comprising a main panel having a contact surface intended to make electrical contact with a current collection tab, and a positioning blade integral with the main panel, said positioning blade being folded towards the contact surface around an axis substantially parallel to the lateral direction, the positioning blade and the main panel being intended to block between them a translation of the current collection tab.

[0015] The previously described provisions allow for a primary current collector configured to facilitate the positioning of the electrode assembly within the prismatic battery cell casing. This enables pre-positioning of the electrode assemblies when the current collection tabs of said electrodes come into contact with the main plate and the positioning blade. Synergistically, the positioning of the current collection tabs between the main plate and the positioning blade maintains their position relative to the primary current collector, thus simplifying the welding process.

[0016] The primary current collector may also have one or more of the following characteristics, taken alone or in combination.

[0017] According to one embodiment, the positioning blade has a positioning surface facing the contact surface of the main panel.

[0018] Thus, the contact surface and the positioning surface define a space between them intended to receive the current collection tab. Positioning the current collection tab relative to the primary current collector is therefore facilitated.

[0019] According to one embodiment, the main panel has a panel length measured along the lateral direction and in which the positioning blade has a blade length measured along the lateral direction, a ratio of the blade length to the panel length being between 0.7 and 1.0.

[0020] In this way, the positioning blade has sufficient length to allow precise positioning of the current collection tab between the main pan and the positioning blade.

[0021] According to one embodiment, at least one of the lateral legs includes a notch formed at the proximal end.

[0022] In this way, it is possible to design a preferred folding area for the side tab, at the notch. This makes it easier to fold during manufacturing.

[0023] According to one embodiment, for each lateral leg, the positioning blade extends in a plane substantially parallel to a plane of the main panel.

[0024] Thus, the positioning blade and the main face define a narrow space into which the current collection tab is intended to be inserted. This allows for more precise pre-positioning of the current collection tab.

[0025] The object of the invention can also be achieved through the implementation of an assembly for a prismatic electric battery cell comprising: a cover including a first terminal and a second terminal of opposite polarity to the first terminal; a secondary current collector electrically connected on one side to the first terminal and intended on the other side to be electrically connected to first electrodes; and a primary current collector electrically connected on one side to the second terminal and intended on the other side to be electrically connected to second electrodes distinct from the first electrodes; an assembly in which the primary current collector is a primary current collector as described above.

[0026] The arrangements described above make it possible to propose an assembly for prismatic battery cells configured both to collect the current from the battery cell, to ensure a watertight seal by the cover of the battery cell case, and to pre-position the electrode assemblies efficiently relative to the cover, and therefore relative to the battery cell case.

[0027] According to one embodiment, the secondary current collector comprises: an upper part electrically connected to the first terminal of the cover; and a lateral part, forming at a non-zero angle with the upper part and intended to be electrically connected to current collection tabs of the first electrodes of the battery cell, the lateral part comprising at least two lateral arms each extending between a proximal end portion fixed to the upper part, and a free distal end portion; each lateral arm comprising: o a main body extending in the lateral direction and intended to come into electrical contact with a current collection tab of the first electrodes;and a foldable stop forming the free distal end portion of said lateral arm, said foldable stop being folded around a folding axis substantially perpendicular to the lateral direction, so as to form a stop surface at which said current collection tab is intended to bear.

[0028] In this way, the secondary and primary current collectors are configured to allow precise positioning of the current tabs of the first and second electrodes relative to the cover. This makes it possible to form a rigid assembly of elements intended to be inserted into the prismatic battery cell casing.

[0029] The object of the invention can also be achieved through the implementation of a prismatic battery cell for an electric propulsion vehicle, said battery cell comprising: a casing having a prismatic shape, the casing having a top opening and internally delimiting a housing; at least two electrode assemblies arranged in the housing where each assembly comprises the successive assembly of first and second electrodes of opposite polarity and separated from each other by a porous separator film; the second electrodes each having a current-collecting tab projecting from the assembly and being configured to collect an electric current from said second electrode;an assembly as described above, in which the cover provides a tight seal of the upper opening of the housing, in which the secondary current collector is electrically connected to the first electrodes, and in which the main panes of the primary current collector are respectively in electrical contact with one of the current collection tabs of the second electrodes, the positioning blades being folded around the current collection tabs of the second electrodes so that each current collection tab is arranged between the main pane and the positioning blade.

[0030] The arrangements described above make it possible to propose a battery cell in which the grouping formed by the cover, the assembly, and the electrode assemblies facilitates its positioning in the housing defined by the casing.

[0031] The battery cell may also exhibit one or more of the following characteristics, taken alone or in combination.

[0032] According to one embodiment: the housing has a housing width measured along a transverse direction defined perpendicular to the lateral direction; wherein the two electrode assemblies each have an assembly thickness measured along the transverse direction; and wherein the two main faces are separated from each other by a positioning distance, said positioning distance being strictly greater than the sum of halves of said assembly thicknesses, and being strictly less than the difference between the housing width and the sum of halves of said assembly thicknesses.

[0033] Thus, the positioning distance between the two main panels allows the position of the electrode assemblies to be fixed simply in relation to the housing of the casing.

[0034] In other words According to one embodiment, the main panels have a panel length measured along the lateral direction, said panel length being less than one third of a length of the housing of the casing, measured along the lateral direction.

[0035] Thus, the length of the main panels allows the position of the electrode assemblies to be fixed vertically relative to the cover.

[0036] According to one embodiment, each current collection tab has a tab width and each main panel has a panel width, a panel width being substantially equal to a tab width.

[0037] Thus, it is possible to ensure optimal current transfer between the current collection tab and the corresponding main panel.

[0038] By "approximately equal", we mean "equal to within 10%".

[0039] According to one embodiment, the primary current collector and the current-collecting tabs of the second electrodes are formed of the same material

[0040] Thus, the electrical connection between the primary current collector and the current collection tabs is improved.

[0041] According to one embodiment, the material of the primary current collector and the current collection tabs of the second electrodes comprises copper.

[0042] Thus, it is possible to maintain a good electrical connection between the primary current collector and the current collection tabs of the battery cell anodes.

[0043] According to one embodiment, the main face of each side leg is welded to the current collection tab with which said main face is in electrical contact.

[0044] In this way, it is possible to keep the electrode assemblies securely attached to the primary current collector, which helps to ensure good stability of the electrode assemblies in the battery cell casing, especially when it is in operation.

[0045] The object of the invention can also be achieved through the implementation of a positioning method for the manufacture of a battery cell as described above, the method comprising the following steps: a step of supplying an assembly as described above, and at least two electrode assemblies; a first connection step, in which the secondary current collector is brought into electrical contact with the first electrodes; a second connection step, in which the primary current collector is brought into electrical contact with the second electrodes via the current collection tabs, the current collection tabs of the second electrodes being snapped between the contact surface and the positioning blade of each lateral leg.

[0046] The previously described provisions allow for a positioning process in which the position of the assemblies relative to the cover is controlled. These steps thus enable the pre-positioning of the electrode assemblies before they are inserted into the battery cell casing.

[0047] The positioning process may also have one or more of the following characteristics, taken alone or in combination.

[0048] According to one embodiment, the second connection step includes a second welding step, in which the main face of each lateral leg of the primary current collector is welded to the current collection tab with which it is in electrical contact.

[0049] Advantageously, the second connection step allows the main face of each side tab to be kept in contact with one of the current collection tabs, which facilitates the welding step.

[0050] According to one embodiment, the first connection step includes, for each lateral arm of the secondary current collector, the folding of the foldable stops around the current collection tabs of the first electrodes, so as to place the main body of each lateral arm in electrical contact with one of the current collection tabs of the first electrodes.

[0051] Thus, the positioning method allows the current collection tabs of the first and second electrodes to be fixed, on the one hand, to the secondary current collector, thereby fixing at least one translation between the assembly and the electrode assemblies, and on the other hand, to the primary current collector, thus fixing at least one other translation between the assembly and the electrode assemblies. It is also possible to form a group of fixed elements between the assembly and the electrode assemblies, which facilitates its insertion into the housing.

[0052] The object of the invention can also be achieved through the implementation of a manufacturing process for a battery cell as described above, the manufacturing process comprising: the steps of the positioning process as described above; a step of providing a prismatic-shaped case having a top opening and internally delimiting a housing; and an introduction step, in which the grouping of elements formed by the assembly and the assemblies is introduced into the housing of the case, the cover ensuring a tight seal of the top opening of the case.The arrangements described above make it possible to propose a method for manufacturing a prismatic battery cell in which the position of the electrode assemblies relative to the cover is controlled by the insertion of the current collection tabs between the contact surface and the positioning blade of each lateral leg, during the second connection step.

[0053] Brief description of the drawings

[0054] Other aspects, objectives, advantages, and features of the invention will become clearer upon reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0055] Figure 1 is a schematic perspective view of an assembly comprising a primary current collector according to the invention when electrically connected to the electrode assemblies of the battery cell.

[0056] Figure 2 is a schematic perspective view of an assembly according to the invention featuring a secondary current collector.

[0057] Figure 3 is another schematic perspective view of an assembly showing the secondary collector of Figure 2.

[0058] Figure 4 is a schematic representation of a positioning method and a manufacturing method according to a particular embodiment of the invention.

[0059] Figure 5 is a schematic representation of the second connection step according to a particular embodiment of the invention.

[0060] Detailed description

[0061] In the figures and throughout the description, the same reference numerals represent identical or similar elements. Furthermore, the various elements are not drawn to scale to ensure clarity. Moreover, the different embodiments and variants are not mutually exclusive and can be combined.

[0062] As can be seen in Figures 1 to 3, the present application relates to a primary current collector 30 for a prismatic electric battery cell 1. The invention relates in particular to a battery cell 1, partially shown in Figures 1 and 2.

[0063] As can be seen in Figures 1 and 2, the battery cell 1 comprises a prismatic housing 4. The housing 4 internally delimits a compartment 9 and has a top opening 8 providing access to this compartment 9. The compartment 9 can extend along a lateral direction, denoted "Z", which corresponds to the direction of insertion of electrode assemblies 50, to be described later. The top opening 8 has a generally rectangular shape in a plane substantially perpendicular to the lateral direction Z.For example, this upper opening 8 can be characterized by an opening length (not shown) measured along a longitudinal direction noted "X", substantially perpendicular to the lateral direction, and by a width, corresponding to a housing width L9, which is measured along a transverse direction noted "Y", and defined substantially perpendicular to the longitudinal direction X and the lateral direction Z.

[0064] Such a housing 9 is configured to receive at least two assemblies 50 of electrodes 51, 53. Each assembly 50 comprises the successive assembly of first and second electrodes 51, 53 of opposite polarity and separated from each other by a porous separating film.

[0065] The first electrode 51 may include a first metal foil in the form of a thin strip, onto which a layer of a first active material is deposited. If the first electrode 51 is a cathode, the first metal foil may be aluminum. The second electrode 53 may include a second metal foil in the form of a thin strip, onto which a layer of a second active material is deposited. If the second electrode 53 is an anode, the second metal foil may be copper.

[0066] The insulating separators are arranged so that no electrical contact is possible between the first electrode 51 and the second electrode 53. The insulating separators also have a porous structure, allowing the passage of an electrolyte comprising ions responsible for the charge transfer between the first electrode 51 and the second electrode 53.

[0067] In the particular case of prismatic battery cells 1, the assemblies 50 generally comprise a stacking or winding of the layers previously described, and in particular two stackings or windings, thus forming two distinct assemblies 50 intended to be housed in a single housing 9. Figures 1 and 2 illustrate in particular an embodiment in which the two assemblies 50 of electrodes 51, 53 each have an assembly thickness e50a, e50b measured along the transverse direction Y.

[0068] Generally, the first electrodes 51 each have a current-collecting tab 55 protruding from the assembly 50. Each current-collecting tab 55 is configured to collect an electric current from said first electrode 51. In the embodiment shown in Figure 2, the battery cell 1 comprises two assemblies 50, and therefore two current-collecting tabs 55 connected to the first electrodes 51 of each of the assemblies 50.

[0069] The second electrodes 53 each have a current-collecting tab 55 projecting from the assembly 50. Each current-collecting tab 55 is configured to collect an electric current from said second electrode 53. In the embodiment shown in Figure 1, the battery cell 1 comprises two assemblies 50, and therefore two current-collecting tabs 55 connected to the second electrodes 53 of each of the assemblies 50. These current-collecting tabs 55 are distinct from those that are electrically connected to the first electrodes 51.

[0070] The battery cell 1 also includes a cover 6 comprising a first terminal 2, visible in Figures 2 and 3, and a second terminal 3 of opposite polarity to the first terminal 2, and visible in Figure 1. The cover 6 ensures a watertight seal of the upper opening 8 of the housing 4.

[0071] Battery cell 1 also includes a secondary current collector 10 for electrically connecting the first electrodes 51 to the first terminal 2, and a primary current collector 30 for electrically connecting the second electrodes 53 to the second terminal 3.

[0072] The primary current collector 30 is a primary current collector 30, one embodiment of which is shown in Figure 1.

[0073] This primary current collector 30 can advantageously be made of the same material as the current collection tabs 55 of the second electrodes 53. This improves the electrical connection between the primary current collector 30 and the current collection tabs 55. More specifically, the material of both the primary current collector 30 and the current collection tabs 55 of the second electrodes 53 can include copper. This allows for maintaining a good electrical connection between the primary current collector 30 and the current collection tabs 55 of the battery cell anodes 1.

[0074] The primary current collector 30 includes first of all an upper section 31 intended to be electrically connected to one of the terminals 2, 3 of the battery cell 1, for example the second terminal 3. This upper section 31 can extend along the longitudinal direction X.

[0075] The primary current collector 30 further comprises a lateral section 40, forming a non-zero angle with the upper section 31. Generally, the lateral section 40 forms an angle of approximately 90° with the upper section 31, so that it extends in the lateral direction Z. This lateral section 40 is intended to be electrically connected to current collection tabs 55 of the electrodes 51, 53 of the battery cell 1, for example, the second electrodes 53. In other words, the primary current collector 30 is electrically connected on one side to the second terminal 3 and electrically connected on the other side to the second electrodes 53, via their current collection tabs 55.As illustrated in Figure 1, the lateral section 40 comprises at least two lateral tabs 41, each extending in the lateral direction Z between a proximal end 41p attached to the upper section 31 and a free distal end 41d. Figure 1 illustrates, in particular, an embodiment in which the lateral section 40 comprises two lateral tabs 41. The number of lateral tabs 41 is generally equal to the number of assemblies 50 present in the battery cell 1, since each lateral tab 41 is electrically connected to one of the assemblies 50 of the battery cell 1 via the current-collecting tabs 55. Furthermore, these lateral tabs 21 can be connected to each other at their proximal ends 41p, thus forming a fork shape.

[0076] It is also possible to provide that at least one of the lateral tabs 41 includes a notch 47 formed at the proximal end 41p. In this way, it is possible to provide a preferential folding area for the lateral tab 41, at the notch 47. This makes it easier to fold the lateral tab 41 during its manufacture.

[0077] Each side tab 41 includes a main face 45 having a contact surface s41 intended to make electrical contact with a current-collecting tab 55. Each current-collecting tab 55 connected to the primary current collector 30 may have a tab width w55 measured along the longitudinal direction X. Each main face 45 may have a face width w45 measured along this longitudinal direction X. It may then be advantageous for the face width w45 to be substantially equal to a tab width w55 with which the main face 45 is in electrical contact. Thus, it is possible to ensure optimal current transfer between the current-collecting tab 55 and the corresponding main face 45. Throughout the text, "substantially equal" means "within 10%" or "within 10°".

[0078] Furthermore, the main flats 45 may have a flat length L45, measured along the lateral direction Z, which is less than one-third of the length of the housing, measured along the lateral direction. Thus, the length of the main flats 45 allows the position of the electrode assemblies 51, 53 to be fixed vertically relative to the cover 6.

[0079] As will be described later, the gap between the two main faces 45 can be used to position the assemblies 50 in the housing 9 of the battery cell 1, or to pre-position the assemblies 50 relative to the cover 6 of the battery cell 1, before the assemblies 50 are inserted into the housing 9. To do this, it is advantageous to provide that the two main faces 45 are separated from each other by a positioning distance denoted "D" chosen relative to the final positioning of the assemblies 50 in the housing 9. For example, this positioning distance D can be chosen to be strictly greater than the sum of halves of the assembly thicknesses e50a, e50b, and to be strictly less than the difference between the housing width L9 and the sum of halves of said assembly thicknesses e50a, e50b. In other words (e50 a + e50 fe). Thus, the positioning distance D between the two main faces 45 allows the position of the electrode assemblies 50 51, 53 to be fixed simply in relation to the housing 9 of the box 4.

[0080] Each lateral leg 41 further includes a positioning blade 43 integral with the main plate 45. Said positioning blade 43 is folded towards the contact surface s41 around an axis substantially parallel to the lateral direction Z.

[0081] Generally, the positioning blade 43 has a positioning surface facing the contact surface s41 of the main plate 45. Thus, the contact surface s41 and the positioning surface define a space between them for receiving the current collection tab 55. Positioning the current collection tab 55 relative to the primary current collector 30 is thereby facilitated. More precisely, for each lateral tab 41, the positioning blade 43 may extend in a plane substantially parallel to a plane of the main plate 45. Thus, the positioning blade 43 and the main plate 45 define a narrow space into which the current collection tab 55 is intended to be inserted. Pre-positioning the current collection tab 55 is therefore more precise.

[0082] The arrangements described above allow, in particular, the positioning blade 43 and the main panel 45 to block, between themselves, a translation of the current collection tongue 55. For example, and as shown in Figure 1, the positioning blade 43 and the main panel both extend in a plane perpendicular to the transverse direction Y. Thus, they allow a translation in both directions of the current collection tongue along the transverse direction Y to be blocked.

[0083] The positioning blade 43 can have a blade length L43 measured along the lateral direction Z. It is then possible to ensure that the ratio of the blade length L43 to the pan length L45 is between 0.7 and 1.0. In this way, the positioning blade 43 has sufficient length to allow precise positioning of the current collection tab 55 between the main pan 45 and the positioning blade 43.

[0084] It is also possible for the main plate 45 and / or the positioning blade 43 of each lateral tab 41 to be welded to the current-collecting tab 55 with which the main plate 45 is in electrical contact. In this way, the electrode assemblies 50 of electrodes 51 and 53 can be secured to the primary current collector 30, thus ensuring good stability of the electrode assemblies 50 of electrodes 51 and 53 within the housing 4 of the battery cell 1, particularly during operation. It is therefore understood that the lateral tabs 41 allow for pre-positioning of the electrodes 53 of the battery cell 1 relative to the primary current collector 30. This facilitates their positioning within the housing 4 of the battery cell 1 before the current-collecting tabs 55 are attached to the primary current collector 30.It is thus possible to ensure that the insertion into the housing 4 will take place under good conditions and harmoniously without risk of contact between the electrodes 53 and the housing 4. Furthermore, the electrodes 53 inserted into the housing 4 are not too close to the lid 6, it is therefore possible to fill the electrolyte with an appropriate flow rate.

[0085] The previously described arrangements allow for a primary current collector 30 configured to facilitate the positioning of the assembly 50 comprising the electrodes 51, 53 in the casing 4 of the prismatic battery cell 1. This makes it possible to pre-position the electrode assemblies 50 of electrodes 51, 53 when the current collection tabs 55 of said electrodes 51, 53 come into contact with the main flat 45 and the positioning blade 43. Synergistically, the positioning of the current collection tabs 55 between the main flat 45 and the positioning blade 43 maintains the position of the current collection tabs 55 relative to the primary current collector 30, thus facilitating welding operations.

[0086] This application also relates to an assembly 7 for a prismatic electric battery cell 1 comprising the cover 6, the secondary current collector 10 electrically connected on one side to the first terminal 2 and intended on the other side to be electrically connected to the first electrodes 51, and the primary current collector 30 of the type described above. An assembly 7 thus formed makes it possible both to ensure a watertight seal of the battery cell 1 casing 4 by the cover 6, and to effectively pre-position the electrode assemblies 50 51, 53 relative to the cover 6, and therefore relative to the battery cell 1 casing 4.

[0087] Although not limiting, it is possible that such an assembly 7 may include a secondary current collector 10 as shown in Figures 2 and 3.

[0088] This secondary current collector 10 may include an upper portion 11 electrically connected to the first terminal 2 of the cover 6. This upper portion 11 may extend along the longitudinal direction X. The secondary current collector 10 may also include a lateral portion 20, forming a non-zero angle with the upper portion 11. Generally, the lateral portion 20 forms an angle with the upper portion 11 of approximately 90°, so that it extends along the lateral direction Z. This lateral portion 20 is intended to be electrically connected to the current collection tabs 55 of the first electrodes 51 of the battery cell 1. In other words, the secondary current collector 10 is electrically connected on one side to the first terminal 2 and electrically connected on the other side to the first electrodes 51.

[0089] The lateral portion 20 may include at least two lateral arms 21, each extending between a proximal end portion 21p attached to the upper portion 11, and a free distal end portion 21d. Similar to the primary current collector 30, the secondary current collector 10 shown in Figures 2 and 3 comprises two lateral arms 21. The number of lateral arms 21 is generally equal to the number of assemblies 50 present in the battery cell 1, since each lateral arm 21 is electrically connected to one of the assemblies 50 of the battery cell 1 via the current-collecting tabs 55. Furthermore, these lateral arms 21 may be connected to each other at their proximal end portions 21p, thus forming a fork shape.

[0090] Each lateral arm 21 may include a main body 23 extending in the lateral direction Z. This main body 23 is intended to come into electrical contact with a current-collecting tab 55 of the first electrodes 51. Each lateral arm 21 may further include a foldable stop 25 forming the free distal end portion 21d of said lateral arm 21.

[0091] The folding stop 25 can be folded about a folding axis X substantially perpendicular to the lateral direction Z, so as to form a stop surface s25 against which the current collection tab 55 is intended to bear. In the embodiments shown, the folding axis X is parallel to the longitudinal direction X, which is why the same reference numeral is used. For example, the folding stops 25 may have a stop length denoted "L25" and measured along the transverse direction Y that is less than or equal to half of one of the assembly thicknesses e50a, e50b.

[0092] Advantageously, the folding stops 25 of the two lateral arms 21 can be folded outwards so that the distal ends of the two lateral arms 21 move away from each other. In this way, it is easier to position the current collection tabs 55 on the stop surfaces 25, while also facilitating the folding of the folding stops 25 against said current collection tabs 55. For example, the folding stop 25 can form an angle with the main body 23 of 90° or less. Thus, the folding stop 25 forms a guide for positioning the current collection tab 55, which allows this current collection tab 55 to be positioned before any welding operation or before its insertion into the housing 4 of the battery cell 1.

[0093] It is also possible, as illustrated in Figure 2, for the folding stops 25 to be folded around the folding axis X to pinch the current collection tab 55. Thus, pinching the current collection tabs 55 between the main body 23 and the folding stop 25 keeps the current collection tabs 55 in contact with the secondary current collector 10, which facilitates welding operations.

[0094] The presence of a secondary current collector 10 as described above and a primary current collector 30 as described above allows for precise positioning of the current tabs of the first and second electrodes 53 relative to the cover 6 in all directions. It is thus possible to form a fixed assembly 7 of elements intended to be inserted into the casing 4 of the prismatic battery cell 1.

[0095] As previously stated, the invention relates to the battery cell 1 comprising the housing 4, at least two assemblies 50 arranged in the housing 9, and an assembly 7 as previously described, in which the secondary current collector 10 is electrically connected to the first electrode 51, in which the main panes 45 of the primary current collector 30 are respectively in electrical contact with one of the current collection tabs 55 of the second electrodes 53, and in which the positioning blades 43 are folded around the current collection tabs 55 of the second electrodes 53 so that each current collection tab 55 is disposed between the main pane 45 and the positioning blade 43.

[0096] The arrangements described above make it possible to propose a battery cell 1 in which the grouping formed by the cover 6, the assembly 7, and the electrode assemblies 51, 53 facilitates its positioning in the housing 9 defined by the casing 4.

[0097] Finally, as illustrated in Figures 4 and 5, the invention relates to a manufacturing method P2 for a battery cell, and a positioning method P1 for manufacturing a battery cell 1 as described above. As illustrated in Figure 4, the positioning method P1 is included in the manufacturing method P2.

[0098] The positioning process P1 includes firstly a supply step E1 of an assembly 7 as described above and of at least two assemblies 50 of electrodes 51, 53.

[0099] The positioning method P1 may include a first connection step E2, in which the secondary current collector 10 is brought into electrical contact with the first electrodes 51. For example, such a first connection step E2 may include a preliminary positioning substep E21, in which the current-collecting tabs 55 of the first electrodes 51 bear respectively on one or the other of the stop surfaces S25 of the folding stops 25 of the secondary current collector 10. It is thus possible to implement the first connection step E2, in which, for each lateral arm 21, the folding stop 25 is folded around the current-collecting tab 55 which bears on this folding stop 25, so as to place the corresponding main body 23 in electrical contact with this current-collecting tab 55.This preliminary positioning sub-step E21 allows in particular to place and fix the position of the electrode assemblies 50 relative to the cover 6 according to the lateral direction Z.

[0100] A second connection step E3 is also implemented, in which the primary current collector 30 is brought into electrical contact with the second electrodes 53 via the current collection tabs 55. This step can be implemented before, after, or simultaneously with the first connection step E2. The positioning process is therefore more adaptable.

[0101] As can be seen in Figure 5, the second connection step E3 includes the snapping E31 of the current collection tabs 55 of the second electrodes 53 between the contact surface s41 and the positioning blade 43 of each lateral leg 41. This allows the position of the electrode assemblies 50 to be fixed along the transverse direction Y.

[0102] Advantageously, the positioning process can include E22, E32 welding steps.

[0103] A first welding step E22 can be implemented during the first connection step E4, and can include welding the main body 23 of each lateral arm 21 of the secondary current collector 10 to the current collection tab 55 with which it is in electrical contact. Advantageously, the preliminary positioning substep E21 allows the main body 23 of each lateral arm 21 to be held in contact with one of the current collection tabs 55, thus facilitating the first welding step E22.

[0104] The second connection step E3 may include a second welding step E32, in which the main face 45 of each lateral leg 41 of the primary current collector 30 is welded to the current collection tab 55 with which it is in electrical contact. Advantageously, bringing each lateral leg 41 into contact with one of the current collection tabs 55 (and in particular the snap-fitting E31 of the current collection tabs 55) prior to carrying out the second welding step E32 facilitates this welding step E32.

[0105] The execution of the first and / or second welding stage E22, E32 allows in particular to fix the position of the electrode assemblies 50 relative to the cover 6 in the longitudinal direction X.

[0106] All the arrangements described above therefore allow us to propose a positioning method P1 in which the position of the assemblies 50 relative to the cover 6 is controlled in all directions X, Y, Z. The steps thus allow us to carry out a pre-positioning of the assemblies 50 of electrodes 51, 53 before inserting them into the housing 4 of the battery cell 1.

[0107] The positioning process P1 as described above is included in the manufacturing process P2 of the battery cell 1. This manufacturing process P2 further includes a step E5 of making available the prismatic housing 4 which has the upper opening 8 and the housing 9. The manufacturing process P2 then includes, after the steps of the positioning process P1, an introduction step E6, in which the group of elements formed by the assembly 7 and the assemblies 50 is introduced into the housing 9 of the housing 4, the cover 6 ensuring a tight seal of the upper opening 8 of the housing 4.

[0108] The arrangements described above allow us to propose a positioning method P2 of a prismatic battery cell 1 in which the position of the electrode assemblies 50 51, 53 relative to the cover 6 is controlled by the insertion of the current collection tabs 55 between the contact surface s41 and the positioning blade 43 of each lateral tab 41, during the second connection step E3.

Claims

DEMANDS 1. Prismatic battery cell (1) for an electric propulsion vehicle, said battery cell (1) comprising: - a casing (4) having a prismatic shape, the casing (4) having a top opening (8) and internally delimiting a housing (9); - at least two assemblies (50) of electrodes (51, 53) arranged in the housing (9) where each assembly (50) comprises the successive assembly (50) of first and second electrodes (51, 53) of opposite polarity and separated from each other by a porous separator film; the second electrodes (53) each having a current-collecting tab (55) projecting from the assembly (50) and configured to collect an electric current from said second electrode (53); - an assembly (7) comprising: a cover (6) including a first terminal (2) and a second terminal (3) of opposite polarity to the first terminal (2), the cover (6) ensuring a tight seal of the upper opening (8) of the housing (4); a secondary current collector (10) electrically connected on one side to the first terminal (2) and on the other side to the first electrodes (51); and a primary current collector (30) comprising on the one hand an upper section (31) electrically connected to the second terminal (3), and on the other hand a lateral section (40), forming a non-zero angle with the upper section (31), said lateral section (40) being electrically connected to the second electrodes (53); the lateral section (40) comprising at least two lateral legs (41) each extending in a lateral direction (Z) between a proximal end (41p) attached to the upper section (31), and a free distal end (41d);each lateral leg (41) comprising a main face (45) having a contact surface (s41) in electrical contact with one of the current-collecting tabs (55) of the second electrodes (53), and a positioning blade (43) integral with the main face (45), said positioning blade (43) being folded towards the contact surface (s41) about an axis substantially parallel to the lateral direction (Z), each positioning blade (43) being folded about one of the current-collecting tabs (55) of the second electrodes (53) so that each current-collecting tab (55) is disposed between the main face (45) and the positioning blade (43), the positioning blade (43) and the main face (45) being; configured to block between them, a translation of the current collection tab (55).

2. Battery cell (1) according to claim 1, wherein the main pan (45) has a pan length (L45) measured along the lateral direction (Z) and wherein the positioning blade (43) has a blade length (L43) measured along the lateral direction (Z), a ratio of the blade length (L43) to the pan length (L45) being between 0.7 and 1.

0.

3. Battery cell (1) according to any one of claims 1 or 2, wherein, for each lateral leg (41), the positioning blade (43) extends in a plane substantially parallel to a plane of the main pan (45).

4. Battery cell (1) according to any one of claims 1 to 3, wherein the secondary current collector (10) comprises: - an upper part (11) electrically connected to the first terminal (2) of the cover (6); and - a lateral part (20), forming a non-zero angle with the upper part (11) and being electrically connected to the current-collecting tabs (55) of the first electrodes (51), the lateral part (20) comprising at least two lateral arms (21) each extending between a proximal end portion (21p) integral with the upper part (11), and a free distal end portion (21d); each lateral arm (21) comprising: • a main body (23) extending in the lateral direction (Z) and in electrical contact with a current-collecting tab (55) of the first electrodes (51); and • a foldable stop (25) forming the free distal end portion (21d) of said lateral arm (21), said foldable stop (25) being folded around a folding axis (X) substantially perpendicular to the lateral direction (Z), so as to form a stop surface (s25) at the level of which said current collection tab (55) comes to rest.

5. Battery cell (1) according to any one of claims 1 to 4, wherein: - the housing (9) has a housing width (L9) measured along a transverse direction (Y) defined perpendicular to the lateral direction (Z); in which - the two electrode assemblies (50) (51, 53) each have an assembly thickness (e50a, e50b) measured along the transverse direction (Y); and in which - the two main panels (45) are separated from each other by a positioning distance (D), said positioning distance (D) being strictly greater than the sum of the halves of said assembly thicknesses (50), and being strictly less than the difference between the housing width (L9) and the sum of the halves of said assembly thicknesses (e50a, e50b).

6. Battery cell (1) according to any one of claims 1 to 5, wherein the main panes (45) have a pan length (L45) measured along the lateral direction (Z), said pan length (L45) being less than one third of a length of the housing (9) of the casing (4), measured along the lateral direction (Z).

7. Battery cell (1) according to any one of claims 1 to 6, wherein each current-collecting tab (55) has a tab width (w55) and each main pan (45) has a pan width (w45), a pan width (w45) being substantially equal to a tab width (w55).

8. Battery cell (1) according to any one of claims 1 to 7, wherein the primary current collector (30) and the current collection tabs (55) of the second electrodes (53) are formed of the same material.

9. Battery cell (1) according to claim 8, wherein the material of the primary current collector (30) and of the current collection tabs (55) of the second electrodes (53) comprises copper.

10. Battery cell (1) according to any one of claims 1 to 9, wherein the main pane (45) of each side tab (41) is welded to the current-collecting tab (55) with which said main pane (45) is in electrical contact.

11. Positioning method (P1) for manufacturing a battery cell (1) according to any one of claims 1 to 10, the method comprising the following steps: - a supply step (E1) of at least two electrode assemblies (50) (51, 53) and an assembly (7), the assembly (7) comprising: a cover (6) including a first terminal (2) and a second terminal (3) of opposite polarity to the first terminal (2); a secondary current collector (10) electrically connected to the first terminal (2); and a primary current collector (30) including an upper section (31) electrically connected to the second terminal (3), and a lateral section (40), forming a non-zero angle with the upper section (31), said lateral section (40) including at least two lateral tabs (41) each extending in a lateral direction (Z) between a proximal end (41p) integral with the upper section (31), and a free distal end (41d); each lateral leg (41) comprising a main face (45) having a contact surface (s41), and a positioning blade (43) attached to the main panel (45), said positioning blade (43) being folded towards the contact surface (s41) around an axis substantially parallel to the lateral direction (Z); - a first connection stage (E2), in which the secondary current collector (10) is brought into electrical contact with the first electrodes (51); - a second connection stage (E3), in which the primary current collector (30) is brought into electrical contact with the second electrodes (53) via current collection tabs (55), the current collection tabs (55) of the second electrodes (53) being snapped (E31) between the contact surface (s41) and the positioning blade (43) of each lateral leg (41).

12. Positioning method (P1) according to claim 11, wherein the second connection step (E3) comprises a second welding step (E32), in which the main face (45) of each lateral leg (41) of the primary current collector (30) is welded to the current collection tab (55) with which it is in electrical contact.

13. Positioning method (P1) according to any one of claims 11 or 12, wherein the supply step (E1) comprises supplying an assembly (7) in which the secondary current collector (10) comprises: - an upper part (11) electrically connected to the first terminal (2) of the cover (6); and - a lateral part (20), forming at a non-zero angle with the upper part (11), the lateral part (20) comprising at least two lateral arms (21) each extending between a proximal end portion (21p) integral with the upper part (11), and a free distal end portion (21d); each lateral arm (21) comprising a main body (23) extending in the lateral direction (Z), and a foldable stop (25) forming the free distal end portion (21d) of said lateral arm (21), said foldable stop (25) being folded around a folding axis (X) substantially perpendicular to the lateral direction (Z), so as to form a stop surface (s25);the first connection step (E2) then comprising for each lateral arm (21) of the secondary current collector (10), the folding of the foldable stops (25) around the current collection tabs (55) of the first electrodes (51), so as to place the main body (23) of each lateral arm (21) in contact; electrical with one of the current collection tabs (55) of the first electrodes (51).

14. Manufacturing process (P2) of a battery cell (1) according to any one of claims 1 to 10, the manufacturing process (P2) comprising: - the steps of the positioning process (P1) according to any one of claims 11 to 13; - a step of providing (E5) a prismatic-shaped housing (4) having a top opening (8) and internally delimiting a housing (9); and - an introduction step (E6), in which the grouping of elements formed by the assembly (7) and the assemblies (50) is introduced into the housing (9) of the housing (4), the cover (6) ensuring a tight seal of the top opening (8) of the housing (4).

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