Rivet for a rechargeable electric cell

Abstract

The invention relates to an electrically conductive rivet (100) that allows a current collector and a terminal to be joined to a cover for a rechargeable electric cell and allows the current collector to be electrically connected to the terminal. The rivet (100) comprises a head (101) and a body (102) extending from the head (101) and comprising a deformable end (103) configured to deform in order to allow riveting. The body (102) comprises a shoulder (104) forming a bearing face for the terminal and at least one projection (105) arranged on a base (104a) of the shoulder (104). The at least one projection (105) connects a portion (108) of the body (102) to the base (104a). The shoulder (104) is arranged between the head (101) and the portion (108) of the body, the at least one projection (105) being intended to penetrate the terminal.

Description

Rivet for rechargeable electric cell Technical field of the invention

[0001] The technical field of the invention relates to the field of rechargeable electric cells.

[0002] More specifically, the invention relates to an electrically conductive rivet for assembling a current collector and a terminal to a cover for a rechargeable electric cell. Prior art

[0003] A prismatic rechargeable electric cell typically comprises a casing, electrodes housed within the casing, and an electrolyte also housed within the casing, with the electrodes immersed in the electrolyte. The prismatic rechargeable electric cell further includes a cover attached to the casing, two terminals, and two current collectors. Each current collector is electrically connected to one of the two terminals and to at least one of the electrodes. The cover is positioned between the terminals and the two current collectors, so that the current collectors are located within the casing, and the terminals are accessible from outside the prismatic rechargeable electric cell for re-establishing contact.

[0004] To ensure electrical continuity between each current collector and its corresponding terminal, an electrically conductive rivet is used to connect the current collector and the corresponding terminal, securing them to the cover by riveting. The rivet is typically riveted to the corresponding terminal by pressing material onto it.

[0005] As a result, the rivet comprises a head bearing against the current collector, and a body extending from the head through the cover and then the terminal; this creates a region of weakness at the interface between the rivet and the terminal. During operation of the prismatic rechargeable cell, this region of weakness can lead to electrolyte leakage and / or loss of electrical continuity between the terminal and the current collector. Indeed: • The prismatic rechargeable electric cell may be subjected to vibrations, for example in the case of use in a vehicle, which may damage the electrical contact between the rivet and the terminal on which it is riveted and which may, depending on the case, induce fluid communication between the inside and outside of the prismatic rechargeable electric cell, which may result in a loss of electrolyte; • The cover may be subject to temperature variations which may induce expansion and contraction between the rivet and the connection terminal which may also induce fluid communication and / or deterioration of the electrical contact.

[0006] Therefore, there is a need to make the assembly of a terminal and a current collector to the cover of the rechargeable electrical cell, particularly prismatic, more robust. Object of the invention

[0007] The present invention aims at a rivet that makes a rechargeable electric cell more robust.

[0008] The invention relates to an electrically conductive rivet for assembling a current collector and a terminal to a cover for a rechargeable electric cell and for electrically connecting the current collector to the terminal, the rivet comprising: • a head; • a body extending along an axis of extension from the head and comprising a deformable end, the deformable end being distal to the head and configured to deform in order to provide riveting; the body comprising: • a shoulder forming a bearing surface for the terminal, said bearing surface being turned towards the deformable end; and • at least one projection arranged at a base of the shoulder and connecting a part of the body to said base, the shoulder being arranged, along the axis of extension, between the head and the part of the body, said at least one projection being intended to penetrate the boundary.

[0009] The rivet may also include one or more of the following characteristics.

[0010] According to a characteristic of the rivet, said at least one projection is annular.

[0011] According to a characteristic of the rivet, the rivet includes several projections arranged at the base of the shoulder and distributed around the axis of extension.

[0012] According to a feature of the rivet, said at least one projection is a crenellated annular projection comprising a base arranged at the base of the shoulder and crenellations arranged on the base, the tops of the crenellations being turned away from the head.

[0013] According to a characteristic of the rivet, said at least one projection has a height hl, measured from the shoulder, of between 0.05 mm and 0.25 mm.

[0014] According to a characteristic of the rivet, said at least one projection has a dimension dl, measured perpendicular to the axis of extension, of between 0.1 mm and 0.6 mm.

[0015] According to a feature of the rivet, the head includes a boss at its interface with the body.

[0016] According to a characteristic of the rivet, the rivet comprises a first longitudinal end and a second longitudinal end opposite the first longitudinal end, the head constituting the first longitudinal end and the deformable end constituting the second longitudinal end.

[0017] The invention also relates to an assembly for a rechargeable electric cell comprising a current collector, a terminal, a cover arranged between the terminal and the current collector, and an electrically conductive rivet as described, the rivet being riveted such that: • ensure the assembly of the current collector and the terminal to the cover; • ensure that the terminal is stressed against the bearing face formed by the shoulder of the rivet body and against said at least one projection; • ensure electrical continuity between the terminal and the current collector.

[0018] The assembly for rechargeable electric cell may be such that the riveting of the rivet induces a deformation of the terminal by penetration of said at least one protrusion into the terminal.

[0019] The assembly may be such that the rivet includes a deformed end which, together with the head, in contact with the current collector, rivets a set of parts comprising successively the current collector, the cover and the terminal, the rivet exerting a clamping force on the set of parts between its head and its deformed end.

[0020] The invention also relates to a rechargeable electric cell comprising: • a case; • electrodes arranged in the housing; • an electrolyte arranged in the casing; • a rechargeable electric cell assembly as described, mounted in the housing and whose current collector is electrically connected to at least one of the electrodes.

[0021] The rechargeable electric cell can be prismatic.

[0022] The rechargeable electric cell can be such that the rivet head is positioned in the casing.

[0023] Other features and benefits may emerge from the detailed description that follows. Brief description of the drawings

[0024] The invention will be better understood upon reading the detailed description that follows, given only by way of non-limiting example and made with reference to the drawings attached and listed below.

[0025] Figure 1 schematically represents a cross-sectional view of a rechargeable electrical cell equipped with rivets according to an embodiment of the present invention.

[0026] Figure 2 represents, in perspective view, the rivet according to a particular embodiment of the invention.

[0027] Figure 3 is a side view of the rivet in Figure 2.

[0028] Figure 4 is a cross-sectional view of the rivet along section AA shown in figure

[0029] Figure 5 is a perspective view of the rivet according to another embodiment of the present invention.

[0030] In these figures, the same references are used to designate the same elements. The elements represented in the different figures are not necessarily drawn to scale in order to facilitate understanding of the figures. Detailed description

[0031] In this description, "between two values" means a range of values ​​including said two values.

[0032] Figure 1 schematically represents a cross-sectional view of a rechargeable 1000 electrical cell comprising a current collector 201, a terminal 202, also called the connection terminal 202, and a cover 203. The current collector 201, the terminal 202 and the cover 203 are assembled by riveting, i.e. using a rivet 100 ensuring the assembly.

[0033] Preferably, and as illustrated in Figure 1, the 1000 rechargeable electric cell is prismatic. This type of rechargeable electric cell is particularly well-suited for storing and releasing electrical energy, for example in the field of electric vehicles.

[0034] The invention relates to the electrically conductive rivet 100, for example as illustrated in figures 2 to 4 according to a first embodiment and in figure 5 according to a second embodiment, for assembling the current collector 201 and the terminal 202 to the cover 203 for rechargeable electric cell 1000, and for electrically connecting the current connector 201 to the terminal 202.

[0035] Rivet 100 is electrically conductive because it is intended, in addition to ensuring the aforementioned assembly, to form an electrical link between the current collector 201 and the terminal 202.

[0036] The rivet 100 comprises a head 101 and a body 102 extending along an axis Al of extension from the head 101. The body 102 includes a deformable end 103. The deformable end 103 is distal to the head 101 (i.e., opposite the head 101) and configured to deform in order to provide riveting.

[0037] Body 102 includes: • a shoulder 104 forming / delimiting a bearing face for the terminal 202, said bearing face being turned towards the side of the deformable end 103 (in other words, the bearing face is oriented in a direction opposite to the head 101); and • at least one projection 105 arranged at a base 104a of the shoulder 104 and intended to penetrate the terminal 202. Specifically, said at least one projection 105 connects a part 108 of the body 102 to said base 104a. The shoulder 104 is arranged, along the extension axis Al, between the head 101 and the part 108 of the body 102. In other words, the shoulder 104 is arranged at a level, along the extension axis Al, between a level where the head 101 is located and a level where the part 108 of the body 102 is located. Therefore, said at least one projection 105 is arranged at a distance from the head 101.

[0038] Thus, said at least one projection 105 allows a deformation of the terminal 202 during the riveting operation until the terminal 202 is pressed against the bearing face, which creates between the rivet 100 and the terminal 202 a satisfactory friction contact, in particular due to the penetration of said at least one projection 105 into the terminal 202, at the level of the shoulder 104 and of said at least one projection 105 for a better stability of the assembly of the terminal 202 and the current collector 201 to the cover 103 using this rivet 100.

[0039] More specifically, by "said at least one projection 105 connects a part 108 of the body 102 to said base 104a", it is understood that said at least one projection 105 includes an interface with the base 104a of the shoulder 104 and an interface with said part 108, and this at least locally around (i.e. locally or all around) the axis Al of extension of the body 102.

[0040] In fact, from the head 101, the rivet 100 can successively comprise a first part 106, a second part 107 and a third part 108 corresponding to said part 108 of the aforementioned body 102.

[0041] In particular, the first part 106 makes it possible to delimit, at the periphery of the second part 107, the shoulder 104 turned in a direction opposite to the head 101.

[0042] The first part 106 can be a right cylinder, called the first cylinder, in particular a right circular cylinder (i.e. presenting a circular section orthogonally to the extension axis Al).

[0043] Specifically, the second part 107 includes at least one projection 105 and is contained within a right cylinder, referred to as the second cylinder, in particular a right circular cylinder. The diameter of the second cylinder is, of course, strictly smaller than the diameter of the first cylinder in order to define the shoulder 104. The second part 107 may also include a portion of the body 102 extending from the third part 108 at the interface between the second part 107 and the third part 108, this portion of the body 102 extending to the first part 106 at a plane including the bearing face / shoulder 104.

[0044] In particular, the third part 108 comprises the deformable end 103 and is in the form of a straight cylinder, referred to as the third cylinder, specifically a right circular cylinder. The diameter of the third cylinder is, of course, strictly smaller than the diameter of the second cylinder in order to delimit at least one projection 105 between the first cylinder and the third cylinder.

[0045] The first, second and third cylinders are preferentially coaxial along, and for example coincide with, the Al extension axis.

[0046] For example, as illustrated in figures 2 to 5: • the first part 106 extends from the head 101; • the second part 107 extends from the first part 106 so that the shoulder 104 is delimited at the periphery of the interface of the second part 107 with the first part 106; • the third part 108 extends from the second part 107 so as to allow the said to be delimited at least one projection 105 between the first part 106 and the third part 108.

[0047] The extension axis Al passes through the body 102 and in particular through the center of the deformable end and the center of the head 101.

[0048] In particular, rivet 100 is a surface of revolution with its axis coinciding with the Al extension axis.

[0049] Rivet 100, as illustrated in Figures 2 to 5, can comprise a first longitudinal end and a second longitudinal end opposite the first longitudinal end, particularly along the extension axis Al. In this case, the head 101 constitutes the first longitudinal end and the deformable end 103 constitutes the second longitudinal end. Rivet 100 therefore does not extend from the head 101 opposite the body 102, making it compact.

[0050] The said at least one projection 105 can be annular as shown for example in figures 2 to 4.

[0051] The fact that the projection 105 is annular allows two additional intersecting contact surfaces compared to a simple shoulder 104 whose base would lack a projection 105: this therefore increases friction to avoid electrical disconnections of the terminal 202 from the rivet 100 which would lead to electrical isolation of the terminal 202 from the current collector 201.

[0052] In fact, when said at least one projection 105 is annular, the latter forms a single projection 105 between the first part 106 and the third part 108 which it connects as the second part 107. According to another formulation, the projection 105 then makes it possible to form locally a shoulder / step between the shoulder 104 and the deformable end 103 along the extension axis Al.

[0053] According to a different embodiment with the annular projection 105, the rivet 100 comprises several projections 105 arranged at the base of the shoulder 104 and distributed around the axis Al of extension of the body 102 from the head 101. This embodiment is particularly visible in figure 5 where the projections are separated by a space in pairs in the manner of crenellations extending from the bearing face formed by the shoulder 104, and in particular from the portion of the body 102 which comprises the second part 107.

[0054] This ensures a better electrical connection between terminal 202 and rivet 100 once riveted to terminal 202.

[0055] In particular, the projections 105 are then distributed at intervals, preferably regular, on the shoulder 104 at its base.

[0056] According to yet another embodiment, said at least one projection 105 is a crenellated annular projection 105 comprising a base arranged at the base of the shoulder 104 and crenellations arranged on the base, the apexes of these crenellations being turned away from the head 101.

[0057] This other design also allows a satisfactory electrical connection between terminal 202 and rivet 100 once riveted to terminal 202.

[0058] This other embodiment with a 105 annular crenellated projection is not shown; it corresponds to combining what is visible in Figure 2, where the reference 105 would be the base, with Figure 5 where the 105 projections would be distributed on said base.

[0059] The said at least one projection 105 may have a height hl (see in particular in figure 4), measured from the shoulder 104 (in particular along a measurement direction parallel to the axis Al of extension), between 0.05 mm and 0.25 mm, and preferably equal to 0.15 mm.

[0060] Such a height hl allows for greater friction between rivet 100 and terminal 202, and enables rivet 100 to ensure a more stable electrical connection with terminal 202 under difficult environmental conditions.

[0061] The said at least one projection 105 may have a dimension dl, measured perpendicular to the axis Al of extension, between 0.1 mm and 0.6 mm, and preferably equal to 0.15 mm.

[0062] Such a dimension dl allows for greater friction between rivet 100 and terminal 202, and enables rivet 100 to ensure a more stable electrical connection with terminal 202 under difficult environmental conditions.

[0063] More specifically, the dimension dl is such that said at least one projection 105 forms an annular shoulder of width equal to dl.

[0064] The head 101 may include a boss 109 at its interface with the body 102.

[0065] The boss 109 is a keying feature allowing satisfactory coupling of the rivet 100 with the current collector 201 and the boss 109 provides a point of contact with the current collector 201 for welding to the rivet 100.

[0066] More specifically, the head 101 may include a collar 110 on which the boss 109 is formed and from which extends the first part 106 of the body 102.

[0067] The body 102 can be solid except at least at its deformable end 103 which is delimited by a cavity 111 formed in the body 102.

[0068] The cavity 111 formed in the body 102 allows to promote the deformation of the rivet 100 during the riveting operation.

[0069] As can be seen in figures 2, 4 and 5, the cavity 111 formed in the body 102 can be of frustoconical shape whose opening at the end of the body 102 opposite the head 101 has a surface greater than the surface of the bottom 112 of the cavity 111 formed in the body 102. It results in a wall 113 (also called lateral wall or flank) of the cavity 111 formed in the body 102 diverging from the bottom 112 of the cavity 111 formed in the body 102 in a direction opposite to the head 101.

[0070] For example, the wall 113 of the cavity 111 formed in the body 102 has an angle α with the bottom 112 of the cavity 111 formed in the body 102 between 95 degrees and 145 degrees, and preferably equal to 120 degrees.

[0071] The cavity 111 formed in the body 102 can include a depth, in particular measured along the axis Al of extension) of between 40% and 80% of the height of the third part 108.

[0072] According to a particular embodiment, the rivet 100 may have the following dimensions measured along a dimension perpendicular to the extension axis Al of the body 102: • the collar 110 has a diameter d2 between 11.9 mm and 12.1 mm, preferably equal to 12 mm; • the boss 109 has a diameter d3 between 9.9 mm and 10.1 mm, preferably equal to 10 mm; • the first part 106 of the body 102 has a diameter d4 between 8.1 mm and 8.3 mm, preferably equal to 8.2 mm; • the second part 107 of the body 102 has a diameter d5 between 6.7 mm and 6.9 mm, preferably equal to 6.8 mm; • the third part 108 of the body has a diameter d6 between 5.9 mm and 6.1 mm, preferably equal to 6 mm. Furthermore, rivet 100 can have the following dimensions measured along a dimension parallel to the extension axis Al of body 102: • a head dimension d7 between 1.4 mm and 1.6 mm; • a dimension d8 of the collar 101 between 0.4 mm and 0.6 mm; • a cumulative dimension d9 of the dimension d7 of the head 101 and of the dimension of the first part 106 between 4.5 mm and 4.7 mm; • a total rivet dimension dlO of 100 between 8 mm and 8.2 mm. Of course, these values ​​can be adapted according to the context.

[0073] Rivet 100 can be based on a material (i.e., include entirely or at least predominantly this material) such as aluminum or copper depending on the type of current collector, which can be anode or cathode, to be connected to terminal 202.

[0074] For example, rivet 100 can be made of / based on aluminium, in particular AL1050, if terminal 202 is a cathode terminal made of / based on aluminium, for example AL3003, and if current collector 201 is a cathode collector made of / based on aluminium for example AL1050.

[0075] For example, rivet 100 can be copper-based, in particular copper Cl 100, nickel-plated if terminal 202 is an aluminum-based anode terminal, for example AL3003, and if current collector 201 is an anode collector comprising copper, for example Cl 100 or Cu OF for "copper oxygen free".

[0076] The lid 203 can be made of / based on aluminium, for example in AL3003.

[0077] The invention also relates to an assembly 200 for a rechargeable electric cell 1000, for example prismatic (see, for example, Figure 1), comprising the current collector 201, the terminal 202, the cover 203 arranged between the terminal 202 and the current collector 201, and the rivet 100 as described. The rivet 100 is riveted so as to: • ensure the assembly of the current collector 201 and the terminal 202 to the cover 203; • ensure that the terminal 202 is stressed against the bearing face formed by the shoulder 104 of the body 102 of the rivet 100 and against said at least one projection 105; • ensure electrical continuity between terminal 202 and current collector 201.

[0078] This has the advantage of limiting the risk of leaks at the interface between rivet 100 and terminal 202 by increasing the friction forces at their interface.

[0079] The riveting of rivet 100 is such that its deformable end 103 is deformed within the assembly 200 for the 1000 rechargeable electric cell. In other words, within the assembly 200 for the 1000 rechargeable electric cell, rivet 100 has a deformed end 114 which, together with the head 101 (and more specifically the collar 110), rivets a set of parts comprising successively the current collector 201, the cover 203, and the terminal 202.

[0080] Preferably, the rivet 100 exerts a clamping force on the assembly of parts between its head 101 and its deformed end 114, for example forming a riveting bead on the connection terminal 202, the head 101 being in particular in contact with the current collector 201.

[0081] This tightening effort tends to limit electrolyte leaks from the rechargeable 1000 electric cell.

[0082] It follows from what has been described above that the deformed end 114 is obtained in particular by deformation of the deformable end 103 of the rivet 100. The deformed end 114 is in particular in contact with the terminal 102 as illustrated in figure 1.

[0083] Thus, the body 102 of the rivet 100 can pass through at least the current collector 201 and the cover 203 before cooperating via its deformed end 114 with the terminal 202.

[0084] The assembly of parts may also include a seal 204 to contribute to the sealing of the rechargeable electric cell 1000. The seal 204 can then be mounted on the body 102 and be in contact with the current collector 201 on one side, and on the other side with an opening 205 made through the cover 203 and through which the body 102 passes, as shown for example in Figure 1.

[0085] Preferably, riveting rivet 100 induces deformation of terminal 202 by penetration of said at least one projection 105 into terminal 202.

[0086] Thanks to this deformation, it allows intimate contact between rivet 100 and terminal 202, thus improving the friction between rivet 100 and terminal 202 in order to avoid electrolyte leaks and ensure good electrical contact between rivet 100 and terminal 202.

[0087] This deformation is clearly identifiable when disassembling and studying the assembly 200 for a 1000 rechargeable electric cell.

[0088] In one embodiment, terminal 202 is a cathode terminal, and current collector 201 is a cathode collector. Assembly 200 for a 1000 mAh rechargeable electric cell can then include an anode collector 206, an anode terminal 207, and cover 203 arranged between the anode terminal 207 and the anode collector 206. Assembly 200 also includes a second electrically conductive rivet 115 as described above.

[0089] The second rivet 115 is riveted in such a way that: • ensure the assembly of the anode collector 206 and the anode terminal 207 to the cover 203; • ensure that the anode terminal 207 is stressed against the bearing face of the second rivet 115 and against said at least one projection 105 of the second rivet 115; • ensure electrical continuity between the anode terminal 207 and the anode collector 206.

[0090] In general, everything that applies to the first rivet 100 in relation to the cathode terminal 202 and the anode collector 201 also applies to the second rivet 115 in relation to the anode terminal 207 and the anode collector 206. Thus, for example, the riveting of the second rivet 115 is such that its deformable end 103 is deformed within the assembly 200 for the rechargeable electric cell 100. In other words, within the assembly 200 for the rechargeable electric cell 1000, the second rivet 115 has a deformed end 114 which, together with its head 101, rivets a group of parts comprising successively the anode collector 206, the cover 203, and the anode terminal 207. Preferably, the second rivet 115 exerts a clamping force on the group of parts between its head 101 and its deformed end 114, for example forming a riveting bead on the anode terminal 207, its head 101 being in particular in contact with the anode collector 206.

[0091] Thus, the body 102 of the second rivet 115 can pass through at least the anode collector 206 and the cover 203 before cooperating with its deformed end 114 with the anode terminal 207.

[0092] The group of parts may also include a seal 208 to contribute to the sealing of the rechargeable electric cell 1000. The seal 208 can then be mounted on the body 102 of the second rivet 115 and be in contact with the anode collector 206 on one side, and on the other side with a through hole 209 provided through the cover 203 and through which the body 102 of the second rivet 115 passes, as shown for example in Figure 1.

[0093] Figure 1 schematically represents assembly 200 for the 100 rechargeable electric cell and the 1000 rechargeable electric cell, in that a person skilled in the art can add other parts according to the desired configuration of assembly 200 for the 1000 rechargeable electric cell. These parts can be integrated into the assembly and / or the group of parts. For example, and without limitation, parts can be incorporated to separate and / or electrically isolate terminal 202 and / or current collector 201 from cover 203.

[0094] The invention also relates to the 1000 rechargeable electric cell, for example, as shown in Figure 1. The 1000 rechargeable electric cell comprises: • a 1001 case; • electrodes 1002 arranged in housing 1001; • an electrolyte 1005 arranged in the casing 1001; • the assembly 200 for rechargeable electric cell mounted in the housing 1001 and whose current collector 201 is electrically connected to at least one of the electrodes 1002 for example by means of tab(s) 1003 or fastener(s).

[0095] Such a 1000 rechargeable electric cell is more robust due to the use of the 100 rivet according to the present invention.

[0096] The 1001 housing can be made of a hard and rigid material, for example a metallic material, the purpose of which is to protect the electrodes.

[0097] In particular, the electrodes 1002 comprise at least one anode and at least one cathode. In this case, said at least one cathode is electrically connected to the cathode collector 201 and said at least one anode is electrically connected to the anode collector 206, notably via respective tabs 1003, 1004.

[0098] In fact, the electrodes 1002 can be integrated within a multilayer winding comprising successively a cathode, a first separator, an anode, and a second separator. This winding can be positioned in the housing of the rechargeable 1000 electric cell where the anode is electrically connected to the anode collector 206 and the cathode is electrically connected to the cathode collector 201, for example, via tabs 1003 and 1004. This is called electrode winding technology.

[0099] As an alternative to winding technology, a stacking technology can be used, for example, implemented by a stacking process consisting of cutting cathode and anode foils to the required size from a roll, then stacking them in layers, each consisting of a cathode foil, a separator, and an anode foil, with two adjacent stacked layers separated by a separator. The stacked layers can then be inserted into the housing 1001, and the cathode foils can be electrically connected to the cathode collector 201 and the anode foils to the anode collector 206.

[0100] The electrodes and separators are immersed in the 1005 electrolyte of the 1000 rechargeable electric cell which allows the passage of ions from one electrode to the other in both directions, depending on whether it is to store energy in the 1000 rechargeable electric cell or to transfer energy from the 1000 rechargeable electric cell.

[0101] For example, as shown in Figure 1, the cover 203 closes an opening in the housing 1001.

[0102] As illustrated in Figure 1, the head 101 of the rivet 100 can be positioned in the housing 1001, in particular so as to exert pressure to tighten the current collector 201 towards the cover 203.

[0103] The invention also relates to a method for manufacturing the assembly 200 for a 1000 rechargeable electric cell, said method comprising the following steps: • provide the current collector 201, the terminal 202, the cover 203 and the rivet 100; • arrange the cover 203 between the terminal 202 and the current collector 201; • Rivet rivet 100, particularly after the step of arranging cover 203 between terminal 202 and current collector 201, so that: o ensure the assembly of the current collector 201 and the terminal 202 to the cover 203; to ensure that the terminal 202 is stressed against the bearing face formed by the shoulder 104 of the body 102 of the rivet 100 and against said at least one projection 105; to ensure electrical continuity between terminal 202 and current collector 201. The step of riveting the rivet 100 involves deforming the deformable end 103 of the rivet 100 away from the head 101 and at a distance from the current collector 201 to obtain the deformed end 114 of the rivet 100. This deformation induces the penetration of said rivet 100 of at least one projection 105 into the terminal 202, resulting in the terminal 202 being brought closer to the head 101. This bringing of the terminal 202 towards the head 101 ensures that the current collector 201 and the terminal 202 are held in position relative to the cover 203 and that good electrical continuity is maintained between the rivet 100 and the terminal 202 due to the penetration of said projection 105 into the terminal 202. The penetration of said projection 105 into the terminal 202 is notably the result of a tightening between the head 101 and the end 114 deformed.The manufacturing process may include a step of welding the current collector 201 to rivet 100, for example, to improve conductivity between the current collector 201 and rivet 100.

[0104] The present invention has an industrial application in the field of batteries, particularly for electric vehicles.

[0105] An electric vehicle is defined as a vehicle comprising at least one motor to drive one or more of the wheels of the electric vehicle using a battery comprising 1000 rechargeable electric cells as described. Such a vehicle may be 100% electric or a hybrid vehicle also equipped with an internal combustion engine.

Claims

Demands 1. Electrically conductive rivet (100) for assembling a current collector (201) and a terminal (202) to a cover (203) for a rechargeable electric cell (1000) and for electrically connecting the current collector (201) to the terminal (202), the rivet (100) comprising: • a head (101); • a body (102) extending along an axis (Al) of extension from the head (101) and comprising a deformable end (103), the deformable end (103) being distal to the head (101) and being configured to deform in order to ensure riveting; the body (102) comprising: • a shoulder (104) forming a bearing surface for the terminal (202), said bearing surface being turned towards the deformable end (103); and • at least one projection (105) arranged at a base (104a) of the shoulder (104) and connecting a part (108) of the body (102) to said base (104a), the shoulder (104) being arranged, along the axis (Al) of extension, between the head (101) and the part (108) of the body, said at least one projection (105) being intended to penetrate the terminal (202).

2. Rivet (100) according to claim 1, wherein said at least one projection (105) is annular.

3. Rivet (100) according to claim 1, comprising several projections (105) arranged at the base of the shoulder (104) and distributed around the axis (Al) of extension.

4. Rivet (100) according to claim 1, wherein said at least one projection (105) is a serrated annular projection (105) comprising a base arranged at the base of the shoulder (104) and crenellations arranged on the base, the apexes of the crenellations being turned away from the head (101).

5. Rivet (100) according to any one of claims 1 to 4, wherein said at least one projection (105) has a height hl, measured from the shoulder (104), of between 0.05 mm and 0.25 mm.

6. Rivet (100) according to any one of claims 1 to 5, wherein said at least one projection (105) has a dimension dl, measured perpendicular to the axis (Al) of extension, of between 0.1 mm and 0.6 mm.

7. Rivet (100) according to any one of claims 1 to 6, wherein the head (101) comprises a boss (109) at its interface with the body (102).

8. Rivet (100) according to any one of claims 1 to 7, comprising a first longitudinal end and a second longitudinal end opposite the first longitudinal end, the head (101) constituting the first longitudinal end and the deformable end (103) constituting the second longitudinal end.

9. Assembly (200) for a rechargeable electric cell (1000) comprising a current collector (201), a terminal (202), a cover (203) arranged between the terminal (202) and the current collector (201), and an electrically conductive rivet (100) according to any one of claims 1 to 8, the rivet (100) being riveted such that: • ensure the assembly of the current collector (201) and the terminal (202) to the cover (203); • ensure that the terminal (202) is stressed against the bearing face formed by the shoulder (104) of the body (102) of the rivet (100) and against said at least one projection (105); • ensure electrical continuity between terminal (202) and current collector (201).

10. Assembly (200) for rechargeable electric cell (1000) according to claim 9 in which riveting of rivet (100) induces deformation of terminal (202) by penetration of said at least one projection (105) into terminal (202).

11. Assembly (200) for rechargeable electric cell (1000) according to any one of claims 9 to 10, wherein the rivet (100) comprises a deformed end (114), and wherein the deformed end (114) together with the head (101), in contact with the current collector (201), rivets an assembly of parts comprising successively the current collector (201), the cover (203) and the terminal (202), the rivet (100) exerting a clamping force on the assembly of parts between its head (101) and its deformed end (114).

12. Rechargeable electric cell (1000) comprising: • a case (1001); • electrodes (1002) arranged in the housing (1001); • an electrolyte (1005) arranged in the casing (1001); • an assembly (200) for a rechargeable electric cell according to any one of claims 9 to 11, mounted to the housing (1001) and having the current collector (201) electrically connected to at least one of the electrodes (1002).

13. Rechargeable electric cell (1000) according to claim 12, said rechargeable electric cell (1000) being prismatic.

14. Rechargeable electric cell (1000) according to any one of claims 12 to 13, wherein the head (101) of the rivet (100) is positioned in the housing (1001).

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