Current collector, prismatic battery cell and associated manufacturing method

Abstract

The invention relates to a current collector (10) for a prismatic electric battery cell (1), the current collector comprising a lateral section (30) intended to be electrically connected to current-collecting tabs (55) of an assembly (50) of electrodes (51, 53) of the battery cell (1), the lateral section (30) extending between a proximal portion (31) and a free distal portion (35), the lateral section (30) comprising a generally planar main portion (33) connecting the proximal portion (31) and the distal portion (35), and forming a recess (d37) relative to the proximal portion (31) and the distal portion (35), to form a cavity (37) intended to receive the current-collecting tabs (55). The invention also relates to an assembly (5) and to a battery cell (1) comprising such a current collector (10).

Description

[0001] DESCRIPTION

[0002] TITLE: Current collector, prismatic battery cell and associated manufacturing process

[0003] Technical field of the invention

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

[0005] More particularly, the invention relates to a current collector for such a prismatic battery cell, as well as an assembly comprising such a current collector.

[0006] State of the art

[0007] In the field of secondary batteries, and particularly batteries for electric vehicles, it is common to manufacture so-called prismatic battery cells. 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 or wound to form one or more electrode assemblies that make up the prismatic battery cell. A porous separator is placed between the anode and the cathode. The electrode assembly is then inserted into a rigid casing that serves to protect the electrode assembly and to allow the insertion of an electrolyte, which facilitates the transport of ions between the two electrodes.

[0008] To maximize battery cell capacity, it is known to create two electrode assemblies designed to be inserted inside the same battery cell casing. Furthermore, the prismatic battery cell cover includes two terminals used for electrical connections with other battery cells.

[0009] To channel the current produced by the electrode assemblies 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.

[0010] To achieve this, it is known in the prior art to fold the current-collecting tabs of the electrodes onto the current collector. When the battery cell comprises two electrode assemblies, it is provided that the current-collecting tab of the first assembly is disposed on one area of ​​the collector, and that the current-collecting tab of the second assembly is disposed on a second area of ​​the current collector.

[0011] While this solution is satisfactory in that it allows for the relative positioning of the two current collection tabs, it can generate differential stresses on the battery cell depending on the load on each electrode assembly. These stresses can lead to less optimal battery cell performance and reduce its lifespan. Furthermore, regardless of the arrangement of the current collection tabs on the current collector, thermal heating is frequently observed in the current collector, which can be detrimental to the battery cell if this heating is excessive at the interface between the cover and the current collector.

[0012] Furthermore, once the current collection is achieved, it is necessary to ensure that the assembly formed by the electrodes and the current collectors is securely fixed inside the casing, to limit any movement of the assemblies relative to the casing, under normal battery operating conditions.

[0013] Therefore, to ensure optimal performance of a prismatic battery cell, precise positioning of the assemblies 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.

[0014] It is indeed necessary to ensure that the electrode assemblies are inserted into the battery cell casing without coming into contact with the casing walls, as this could damage them. Furthermore, once inserted, the assemblies 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 assemblies within the battery cell casing can lead to the disposal of numerous battery cells.

[0015] Therefore, there is a need to find a prismatic battery cell in which: current is efficiently collected at the electrodes and routed to the cover; current collector heating is controlled; and the electrode stacks are reliably and easily positioned within the casing. Object of the invention

[0016] The present invention aims to provide a solution that addresses all or part of the aforementioned problems.

[0017] This goal can be achieved through the implementation of a prismatic electric battery cell current collector comprising: an upper section extending in a longitudinal direction, and 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-collecting tabs of a battery cell electrode assembly, said lateral section extending in a laterally direction between a proximal portion attached to the upper section and a free distal portion, the lateral section comprising a main portion generally flat and connecting the proximal and distal portions, said main portion forming a step relative to the proximal and distal portions, said main portion having a contact face forming with the proximal and distal portions a housing intended to receive the current-collecting tabs.

[0018] The previously described provisions allow for a current collector configured to facilitate the positioning of the electrode assembly within the prismatic battery cell housing. This enables pre-positioning of the electrode assemblies when the current collection tabs of said electrodes are housed within the current collector housing. Synergistically, the positioning of the current collection tabs within the current collector housing maintains their position relative to the current collector, thus simplifying welding operations.

[0019] The current collector may also have one or more of the following characteristics, taken alone or in combination.

[0020] In one embodiment, the main portion forms a notch between 0.3 mm and 1.2 mm relative to the proximal and distal portions, this notch being measured substantially along the longitudinal direction from the contact face intended to be electrically connected to the current-collecting tabs and an outer face of the distal and proximal portions, said contact and outer faces being intended to be opposite the electrode assembly. Thus, the notch is large enough to allow easy positioning of the current-collecting tabs and small enough to allow insertion of the assembly comprising the electrode assemblies and the current collector into the battery cell casing. This facilitates the assembly of the battery cell.

[0021] According to one embodiment, the main portion comprises a thickness strictly less than a thickness of the proximal portion and strictly less than a thickness of the distal portion.

[0022] In this way, during battery cell operation, any heat generated at the current collector is preferentially concentrated in the main portion. This prevents overheating in the proximal portion, which is in contact with electrical insulation that could melt. Furthermore, this improves the weld between the main portion and the current collection tabs.

[0023] According to one embodiment, the ratio of the thickness of the main portion to the thickness of the proximal portion, or to the thickness of the distal portion, is between 0.4 and 0.8.

[0024] This ratio range offers a good compromise between the mechanical strength of the main portion and its ability to dissipate thermal energy. Furthermore, it reduces the amount of material required to manufacture the current collector.

[0025] According to one embodiment, the upper section includes an opening formed through the material constituting the upper section.

[0026] The presence of such an opening allows for the formation of a preferential breaking zone acting as a fuse that can be broken to electrically disconnect the terminal and the electrode.

[0027] According to one embodiment, the proximal portion has a height, measured along the lateral direction, said height being between 6.3 mm and 6.5 mm.

[0028] Thus, the height of the proximal portion allows the main portion to be positioned relative to the battery cell cover, according to a predetermined distance, which allows a compact assembly to be formed.

[0029] According to one embodiment, at least one portion selected from the proximal portion and the distal portion is provided with a notch, said notch being intended to cooperate with an electrically insulating lateral element intended to be interposed between the current collector and the battery cell housing.

[0030] Thus, it is possible to place said lateral element between the current-collecting tabs and the battery cell casing, to electrically isolate the current collector and the current-collecting tabs from the battery cell casing. The object of the invention can also be achieved by implementing a prismatic battery cell assembly comprising: at least one electrode assembly comprising the successive assembly of first and second electrodes of opposite polarity, separated from each other by a porous separator film; the first and second electrodes each having a current-collecting tab projecting from the assembly and configured to collect an electric current from said electrode; a first current collector electrically connected to the current-collecting tabs of the first electrodes;and a second current collector electrically connected to the current-collecting tabs of the second electrodes; at least one current collector selected from the first current collector and the second current collector being a current collector as described above, the current-collecting tabs being arranged in the housing of said at least one current collector.

[0031] The previously described provisions make it possible to offer a battery cell assembly in which the current collection tabs are pre-positioned in the housing, which facilitates the insertion of the assembly into the battery cell housing.

[0032] The assembly may also exhibit one or more of the following characteristics, taken alone or in combination.

[0033] According to one embodiment, the current collection tabs arranged in the housing are fixed to the main portion of the current collector.

[0034] This allows for a more mechanically robust electrical connection between the current collection tabs and the current collector. Synergistically, this also results in a mechanically robust assembly, making it easier to insert into the battery cell casing.

[0035] According to one embodiment, the first current collector and the second current collector are current collectors as described previously.

[0036] In this way, it is possible to pre-position the electrode assemblies on the side of each current collector, thus facilitating positioning in the battery cell housing.

[0037] According to one embodiment, for the first current collector, a ratio of the thickness of the main portion to the thickness of the proximal portion, or to the thickness of the distal portion, is between 0.45 and 0.55; and for the second current collector, a ratio of the thickness of the main portion to the thickness of the proximal portion, or to the thickness of the distal portion, is between 0.7 and 0.8.

[0038] More specifically, the first current collector can be an anode current collector, and the second current collector can be a cathode current collector. The thickness ratios corresponding to the anode and cathode, respectively, are chosen to meet the specific mechanical and thermal resistance requirements of these electrodes.

[0039] According to one embodiment, for the first current collector, the ratio of the thickness of the main portion to the thickness of the proximal portion, or to the thickness of the distal portion, is substantially equal to 0.5; and for the second current collector, the ratio of the thickness of the main portion to the thickness of the proximal portion, or to the thickness of the distal portion, is substantially equal to 0.75.

[0040] The ratios defined in this way allow for optimal performance.

[0041] According to one embodiment, the current tabs of the electrode assemblies are folded on either side of the main portion of the current collector on the contact face, said contact face being opposite the electrode assemblies.

[0042] In this way, it is possible to maximize the contact area between the current collection tabs and the current collector, which facilitates charge transfer between the electrode assemblies and the current collector.

[0043] In one embodiment, the current-collecting tabs are folded over the contact face of the main portion without overlapping. For example, said current-collecting tabs can be folded axially in a symmetrical manner with respect to the main portion of the current collector.

[0044] Thus, it is possible to avoid the formation of differential thermal stresses which generate differential mechanical stresses and differences in thermal conductivity within the battery cell.

[0045] According to one embodiment, the main portion has a main height measured along the lateral direction, and in which each current collection tab electrically connected with said main portion has a tab height measured along the lateral direction, a ratio of the tab height to the main height being between 0.7 and 1.

[0046] Thus, the current collection tabs are arranged over a larger area of ​​the main portion, which allows for more homogenized temperatures and charge concentrations at the current collector. The objective of the invention can also be achieved through the implementation of a prismatic battery cell for an electric vehicle, said battery cell comprising: a casing having a prismatic shape, the casing having a top opening and internally defining a cell compartment; a cover comprising a first terminal and a second terminal, said cover ensuring a watertight seal of the top opening of the casing; an assembly as described above, in which the first current collector is electrically connected to the first terminal and in which the second current collector is electrically connected to the second terminal.

[0047] The previously described provisions make it possible to propose a battery cell in which the positioning of electrode assemblies is facilitated, and in which the creation of thermal and electrical constraints is avoided.

[0048] The battery cell may also exhibit one or more of the following characteristics, taken alone or in combination.

[0049] According to one embodiment, the battery cell comprises a solid or liquid electrolyte, enabling the exchange of ions between the first electrode and the second electrode.

[0050] According to one embodiment, the battery cell further comprises at least one electrically insulating side element disposed in the current collector housing such that the current collection tabs are interposed between the main portion and said side element.

[0051] In this way, the electrically insulating side element allows the current collection tabs to be electrically isolated from the battery cell casing.

[0052] Brief description of the drawings

[0053] 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:

[0054] Figure 1 is a schematic perspective view of a current collector according to a first embodiment of the invention.

[0055] Figure 2 is a schematic perspective view of a current collector according to a second embodiment of the invention. Figure 3 is a schematic side view of the current collector of Figure 1.

[0056] Figure 4 is a schematic view of an assembly according to the invention comprising two current collectors according to the invention.

[0057] Figure 5 is a schematic view of a battery cell according to a particular embodiment of the invention.

[0058] Detailed description

[0059] 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.

[0060] As can be seen in Figures 1 to 3, the invention relates to a current collector 10 for a prismatic electric battery cell 1. This current collector 10 is intended to be connected on the one hand to a terminal 2, 3 of the battery cell 1, and on the other hand to current collection tabs 55 of an assembly 50 of electrodes 51, 53 of the battery cell 1.

[0061] The current collector 10 first includes an upper section 20 extending along a longitudinal direction denoted "X", which is the section of the current collector 10 intended to be electrically connected to the terminal 2, 3 of the battery cell 1. For this purpose, the upper section 20 may advantageously include a contact opening 23, for example circular in shape, intended to allow the passage of a contact member 11 ensuring electrical continuity between the current collector 10 and the terminal 2, 3.

[0062] Furthermore, the upper section 20 may include an opening 25 formed through the material constituting the upper section 20, for example, rectangular in shape. Such an opening 25 is shown on the current collector 10 in Figure 2. The presence of such an opening 25 creates a preferential breaking zone that acts as a fuse, allowing the terminal 2 and the electrode to be electrically disconnected. This is particularly relevant for the current collector 10 intended to be placed on the cathode side, as this is where the thermal heating can be greatest.

[0063] The current collector 10 further comprises a lateral section 30 forming a non-zero angle with the upper section 20, which is the section intended to be electrically connected to the current collection tabs 55. The lateral section 30 extends in a lateral direction denoted "Z", between a proximal portion 31 integral with the upper section 20 and a free distal portion 35. Generally, the lateral section 30 forms an angle of approximately 90° with the upper section 20, such that the lateral direction Z is perpendicular to the longitudinal direction X. The lateral direction Z also generally corresponds to a direction of insertion of the electrode assemblies 51, 53 into a housing 4 of the battery cell 1.

[0064] The lateral section 30 comprises a main portion 33, generally planar, connecting the proximal portion 31 and the distal portion 35. The main portion 33 generally has a main height h33, measured along the lateral Z direction, that is strictly greater than the height of the distal portion 35 and strictly greater than the height h31 of the proximal portion 31, measured along the lateral Z direction. More precisely, the main height h33 is at least four times greater than the height of the distal portion 35 and at least six times greater than the height h31 of the proximal portion 31.

[0065] For example, the height h31 can be between 6.3 mm and 6.5 mm. Thus, the height h31 of the proximal portion 31 allows the main portion 33 to be positioned relative to a cover 6 of the battery cell 1, according to a predetermined distance, which makes it possible to form a compact assembly, and to position according to said predetermined distance, the electrode assembly(ies) 50 51, 53.

[0066] It is also possible that at least one portion selected from the proximal portion 31 and the distal portion 35 is provided with a notch 34. In the embodiment shown in Figures 1 and 2, the proximal portion 31 comprises two opposing notches 34 along a transverse direction denoted "Y" defined perpendicular to the longitudinal direction X and the lateral direction Z. Furthermore, according to this embodiment, the distal portion 35 comprises a notch 34 at its base. These notches 34 are intended to cooperate with an electrically insulating lateral element 7 intended to be interposed between the current collector 10 and the housing 4 of the battery cell 1.Thus, it is possible to bring said lateral element 7 between the current collection tabs 55 and the housing 4 of the battery cell 1, to electrically isolate the current collector 10 and the current collection tabs 55 from the housing 4 of the battery cell 1. The positioning of the notches 34 as shown in the embodiment of Figures 1 and 2 allows this lateral element 7 to be positioned in the transverse direction Y and in the lateral direction Z.

[0067] As can be seen in figures 1 to 3, the main portion 33 forms a step d37 relative to the proximal portion 31 and the distal portion 35, and has a contact face fc33 forming with the proximal portion 31 and the distal portion 35, a housing 37 intended to receive the current collection tabs 55. Advantageously, it can be provided that the main portion 33 forms a step d37 relative to the proximal portion 31 and the distal portion 35 of between 0.3 mm and 1.2 mm. This step d37 is measured substantially along the longitudinal direction X from the contact face fc33 intended to be electrically connected to the current collection tabs 55 and an outer face fe31, fe35 of the proximal and distal portions 31, 35, said contact and outer faces fc33, fe31, fe35 being intended to be opposed to the assembly 50 of electrodes 51, 53.Thus, the recess d37 is large enough to allow easy positioning of the current collection tabs 55, and small enough to allow insertion of the assembly 5 comprising the electrode assemblies 50 51, 53 and the current collector 10 into the housing 4 of the battery cell 1. This facilitates the assembly 50 of the battery cell 1.

[0068] Advantageously, the main portion 33 can have a thickness e33 that is strictly smaller than the thickness e31 of the proximal portion 31 and strictly smaller than the thickness e35 of the distal portion 35. In this way, during the operation of the battery cell 1, any thermal heating occurring at the current collector 10 is preferentially concentrated at the main portion 33. This prevents overheating at the proximal portion 31, which is in contact with an electrical insulator that could melt. Furthermore, this improves the welding of the main portion 33 to the current collection tabs 55.

[0069] More specifically, the ratio of the thickness e33 of the main portion 33 to the thickness e31 of the proximal portion 31, or to the thickness e35 of the distal portion 35, can be between 0.4 and 0.8. This ratio range represents a good compromise between the mechanical strength of the main portion 33 and its ability to dissipate thermal energy. Furthermore, it reduces the amount of material required to manufacture the current collector 10.

[0070] The arrangements described above allow for a current collector 10 configured to facilitate the positioning of the assembly 50, comprising the electrodes 51 and 53, within the casing 4 of the prismatic battery cell 1. This makes it possible to pre-position the electrode assemblies 50 of electrodes 51 and 53 when the current collection tabs 55 of said electrodes 51 and 53 are housed in the recess 37 of the current collector 10. Synergistically, the positioning of the current collection tabs 55 within the recess 37 of the current collector 10 maintains the position of the current collection tabs 55 relative to the current collector 10, thus facilitating welding operations.

[0071] As illustrated in Figure 4, the invention also relates to an assembly 5 for a prismatic battery cell 1. Such an assembly 5 comprises at least one assembly 50 of electrodes 51, 53 comprising the successive assembly of first and second electrodes 51, 53 of opposite polarity and separated from each other by a porous separator film.

[0072] 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.

[0073] The insulating separator(s) 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.

[0074] 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.

[0075] The first and second electrodes 51, 53 each have a current-collecting tab 55 projecting from the assembly 50 and configured to collect an electric current from said electrode.

[0076] The assembly 5 further includes a first current collector 10 electrically connected to the current-collecting tabs 55 of the first electrodes 51, and a second current collector 10 electrically connected to the current-collecting tabs 55 of the second electrodes 53. To facilitate current collection by the current collectors 10, it is advantageous for them to be made of the same material as the electrode with which they are electrically connected. Thus, the first current collector 10 may be made of aluminum, and the second current collector 10 may be made of copper.

[0077] At least one current collector 10, chosen from the first and second current collectors 10, is a current collector 10 according to the invention. Moreover, as illustrated in Figure 4, it is possible for both current collectors 10 to be current collectors 10 according to the invention. In this way, it is possible to pre-position the electrode assemblies 50 51, 53 on the side of each current collector 10, thus facilitating the positioning of the battery cell 1 in the housing 4. It is also possible to provide that, for the first current collector 10, the ratio of the thickness e33 of the main portion 33 to the thickness e31 of the proximal portion 31, or to the thickness e35 of the distal portion 35, is between 0.45 and 0.55, and in particular substantially equal to 0.5.

[0078] Similarly, it is possible to predict that for the second current collector 10, a ratio of the thickness e33 of the main portion 33 to the thickness e31 of the proximal portion 31, or to the thickness e35 of the distal portion 35 is between 0.7 and 0.8, and in particular substantially equal to 0.75.

[0079] The first current collector 10 can be an anode current collector 10, and the second current collector 10 can be a cathode current collector 10. The thickness ratios corresponding to the anode and cathode, respectively, are chosen to meet the specific mechanical and thermal resistance requirements of these electrodes. The ratios thus defined allow for optimal performance.

[0080] The current-collecting tabs 55, which are in electrical contact with a current collector 10 according to the invention, are arranged in the housing 37 of said current collector 10. More specifically, the current-collecting tabs 55 arranged in the housing 37 can be fixed, for example welded, to the main portion 33 of the current collector 10. This makes it possible to make the electrical connection between the current-collecting tabs 55 and the current collector 10 more mechanically robust. Synergistically, this also results in a mechanically robust assembly 5, which makes it easier to insert into the housing 4 of the battery cell 1.

[0081] Although not shown, it is advantageous for the current-collecting tabs of the electrode assemblies 51, 53 to be folded back on either side of the main portion 33 of the current collector 10 onto the contact face fc33, said contact face fc33 being opposite the electrode assemblies 51, 53. In this way, it is possible to maximize the contact area between the current-collecting tabs 55 and the current collector 10, which facilitates charge transfer between the electrode assemblies 51, 53 and the current collector 10. The current-collecting tabs can be folded back onto the contact face fc33 of the main portion 33 without overlapping. For example, said current-collecting tabs 55 can be folded axially symmetrically with respect to the main portion 33 of the current collector 10.Thus, it is possible to avoid the formation of differential thermal stresses which generate differential mechanical stresses and differences in thermal conductivity within the battery cell 1.

[0082] Finally, as can be seen in Figure 4, a ratio of a tab height h55 measured along the lateral direction Z, divided by the main height h33 can be between 0.7 and 1. Thus, the current collection tabs 55 are arranged over a larger area of ​​the main portion 33, which allows for homogenization of temperatures and charge concentrations at the current collector 10.

[0083] The arrangements described above make it possible to propose an assembly 5 for battery cell 1 in which the current collection tabs 55 are pre-positioned in the housing 37, which makes it easier to insert the assembly 5 into the housing 4 of the battery cell 1.

[0084] Finally, with reference to Figure 5, the invention also relates to a prismatic battery cell 1 for an electric propulsion vehicle.

[0085] Battery cell 1 includes a case 4 having a prismatic shape.

[0086] The housing 4 internally delimits a cell housing 9 and has a top opening 8 which provides access to this cell housing 9. The cell housing 9 can extend in the lateral direction Z.

[0087] The battery cell 1 also includes a cover 6 ensuring a watertight seal of the upper opening 8 of the casing 4, a first terminal 2 and a second terminal 3 of opposite polarity to the first terminal 2. Generally the first terminal 2 and the second terminal 3 are two separate parts attached to the cover 6. For this reason, it is advantageous to provide spacers 15 interposed between each terminal 2, 3 and the cover 6.

[0088] The battery cell 1 also includes an assembly 5 according to the invention, in which the first current collector 10 is electrically connected to the first terminal 2 and in which the second current collector 10 is electrically connected to the second terminal 3.

[0089] To prevent any short circuit between the current collectors 10, these are generally electrically isolated from the cover 6 by an insulating element 13, and from the housing 4 by a lateral element 7, both of which are generally electrically insulating. Thus, the current collection tabs 55 can be interposed between the main portion 33 and said lateral element 7. In this way, the electrically insulating lateral element 7 allows the current collection tabs 55 to be electrically isolated from the housing 4 of the battery cell 1.

[0090] Furthermore, it is generally provided that the battery cell 1 includes a contact element 11, such as a rivet, which provides an electrical connection between each terminal 2, 3, and one of the current collectors 10. The contact opening 23 is intentionally provided in the current collectors 10 to allow the passage of such a contact element 11.

[0091] Finally, to allow ion exchange between the first electrode 51 and the second electrode 53, the battery cell 1 generally includes a solid or liquid electrolyte. The arrangements described above make it possible to propose a battery cell 1 in which the positioning of the electrode assemblies 50 51, 53 is facilitated, and in which the creation of thermal and electrical stresses is avoided.

Claims

DEMANDS 1. Current collector (10) for prismatic electrical battery cell (1) comprising - an upper section (20) extending along a longitudinal direction (X), and intended to be electrically connected to a terminal (2, 3) of the battery cell (1); and - a lateral section (30) forming a non-zero angle with the upper section (20) and intended to be electrically connected to current-collecting tabs (55) of an assembly (50) of electrodes (51, 53) of the battery cell (1), said lateral section (30) extending in a lateral direction (Z) between a proximal portion (31) integral with the upper section (20) and a free distal portion (35), the lateral section (30) comprising a main portion (33) generally planar and connecting the proximal portion (31) and the distal portion (35), said main portion (33) forming a recess (d37) with respect to the proximal portion (31) and the distal portion (35), said main portion (33) having a contact face (fc33) forming with the proximal portion (31) and the distal portion (35), a housing (37) intended to receive the tabs current collection (55).

2. Current collector (10) according to claim 1, wherein the main portion (33) forms a step (d37) relative to the proximal portion (31) and the distal portion (35) of between 0.3 mm and 1.2 mm, said step (d37) being measured substantially along the longitudinal direction (X) from the contact face (fc33) intended to be electrically connected to the current collection tabs (55) and an outer face (fe31, fe35) of the distal and proximal portions (31, 35), said contact and outer faces (fc33, fe31, fe35) being intended to be opposed to the electrode assembly (50) (51, 53).

3. Current collector (10) according to any one of claims 1 or 2, wherein the main portion (33) comprises a thickness (e33) strictly smaller than a thickness (e31) of the proximal portion (31) and strictly smaller than a thickness (e35) of the distal portion (35).

4. Current collector (10) according to claim 3, wherein a ratio of the thickness (e33) of the main portion (33) to the thickness (e31) of the proximal portion (31), or to the thickness (e35) of the distal portion (35) is between 0.4 and 0.

8.

5. Current collector (10) according to any one of claims 1 to 4, wherein the upper section (20) includes an opening (25) formed through the material constituting the upper section (20).

6. Current collector (10) according to any one of claims 1 to 5, wherein the proximal portion (31) has a height (h31), measured along the lateral direction (Z), said height being between 6.3 mm and 6.5 mm.

7. Current collector (10) according to any one of claims 1 to 6, wherein at least a portion selected from the proximal portion (31) and the distal portion (35) is provided with a notch (34), said notch (34) being intended to cooperate with an electrically insulating lateral element (7) intended to be interposed between the current collector (10) and the housing (4) of the battery cell (1).

8. Assembly (5) for prismatic battery cell (1) comprising: - at least one electrode assembly (50) (51, 53) comprising the successive assembly of first and second electrodes (51, 53) of opposite polarity and separated from each other by a porous separator film; the first and second electrodes (51, 53) each having a current-collecting tab (55) projecting from the assembly (50) and configured to collect an electric current from said electrode; - a first current collector (10) electrically connected to the current-collecting tabs (55) of the first electrodes (51); and - a second current collector (10) electrically connected to the current collection tabs (55) of the second electrodes (53); at least one current collector (10) selected from the first current collector (10) and the second current collector (10) being a current collector (10) according to any one of claims 1 to 7, the current collection tabs (55) being arranged in the housing (37) of said at least one current collector (10).

9. Assembly (5) according to claim 8, wherein the current collection tabs (55) arranged in the housing (37) are fixed to the main portion (33) of the current collector (10).

10. Assembly (5) according to any one of claims 8 or 9, wherein the first current collector (10) and the second current collector (10) are current collectors according to any one of claims 1 to 7.

11. Assembly (5) according to claim 10, wherein for the first current collector (10), a ratio of the thickness (e33) of the main portion (33) to the thickness (e31) of the proximal portion (31), or to the thickness (e35) of the distal portion (35) is between 0.45 and 0.55; and wherein for the second current collector (10), a ratio of the thickness (e33) of the main portion (33) to the thickness (e31) of the portion proximal (31), or on the thickness (e35) of the distal portion (35) is between 0.7 and 0.

8.

12. Assembly (5) according to claim 11, wherein for the first current collector (10), the ratio of the thickness (e33) of the main portion (33) to the thickness (e31) of the proximal portion (31), or to the thickness (e35) of the distal portion (35) is substantially equal to 0.5; and wherein for the second current collector (10), the ratio of the thickness (e33) of the main portion (33) to the thickness (e31) of the proximal portion (31), or to the thickness (e35) of the distal portion (35) is substantially equal to 0.

75.

13. Assembly (5) according to any one of claims 8 to 12, wherein the current tabs of the electrode assemblies (50) (51, 53) are folded back on either side of the main portion (33) of the current collector (10) on the contact face (fc33), said contact face (fc33) being opposite the electrode assemblies (50) (51, 53).

14. Assembly (5) according to any one of claims 8 to 13, wherein the main portion (33) has a main height (h33) measured along the lateral direction (Z), and wherein each current-collecting tab (55) electrically connected with said main portion (33) has a tab height (h55) measured along the lateral direction (Z), a ratio of the tab height (h55) to the main height (h33) being between 0.7 and 1.

15. 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 cell housing (9) - a cover (6) comprising a first terminal (2) and a second terminal (3), said cover (6) ensuring a tight seal of the upper opening (8) of the housing (4); - an assembly (5) according to any one of claims 8 to 14, wherein the first current collector (10) is electrically connected to the first terminal (2) and wherein the second current collector (10) is electrically connected to the second terminal (3).

16. Battery cell (1) according to claim 15 further comprising at least one electrically insulating side element (7) disposed in the housing (37) of the current collector (10) such that the current collection tabs (55) are interposed between the main portion (33) and said side element (7).

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