Battery

Abstract

The battery (1) comprises a hollow vessel (2) having a side wall (3) and a bottom wall (4) that define an interior space (7), a top portion (8) located on the opposite side of the bottom wall (4) along the axial direction, an electrochemical cell (9) inserted into the interior space (7) of the hollow vessel (2), an insert (15) made of a conductive material, a lid (30) mechanically and electrically connected to the anode of the electrochemical cell (9), and a peripheral portion (31). The insert (15) made of a conductive material is inserted between the top portion (8) of the hollow vessel (2) and the peripheral portion (31) of the lid (2) and includes a connection portion (21) that is in electrical contact with at least the top portion (8) of the hollow vessel (2). The peripheral portion (31) of the lid (30) is in electrical contact with at least the top portion (8) of the hollow vessel (2).

Description

[Technical field]

[0001] The present invention relates to batteries that can be used in applications where electrical energy needs to be made available. [Background technology]

[0002] A battery, also called a secondary electrochemical cell or rechargeable battery, is a device that converts chemical energy into electrical energy through a reversible oxidation-reduction reaction, and then converts electrical energy back into chemical energy by reversing the oxidation-reduction process.

[0003] The battery includes a hollow container into which is inserted an electrochemical cell formed of an anode, a cathode, and a separator disposed between the anode and cathode. The cathode is electrically connected to the bottom base of the container, and the anode is electrically connected to the top plate of the container.

[0004] In some types of applications, the electrochemical cell inserted into the hollow container is a type of electrochemical cell called a jelly roll or Swiss roll, which includes a sheet of insulating material in which anode material, separator material, and cathode material are arranged in succession in thin layers or sheets. The laminate thus constructed is rolled onto itself and inserted into the container. The cathode material is placed at the bottom of the hollow container and makes electrical contact with an electrode that is electrically insulated from the container itself. The anode material is in electrical contact with a lid placed at the end of the container, further forming an electrode.

[0005] Examples of such applications include lithium ion, nickel cadmium and nickel metal hydride batteries.

[0006] Applicant's experience has shown that the sidewall of the hollow vessel must be in electrical contact with the anode material.

[0007] In the applicant's experience, electrical contact between the anode material and the side wall of the hollow vessel is achieved by welding an insert of conductive material (e.g. copper) to the anode material before inserting the electrochemical cell into the hollow vessel. After the electrochemical cell is inserted into the hollow vessel, the insert of conductive material is welded to the inner surface of the side wall inside the hollow of the hollow vessel, and the hollow vessel is closed with a lid. The lid in contact with the vessel (and the vessel in contact with the insert of conductive material) assumes the same electrical potential as the side wall of the hollow vessel.

[0008] Applicant notes that in the battery briefly described above, welding an insert of conductive material to the interior space of the hollow vessel and to the inner surface of the side wall of the hollow vessel may be difficult or, in any case, costly from a large-scale production standpoint.

[0009] Indeed, the applicant has determined that since the welding is performed with the electrochemical cell already inserted in the hollow vessel, the space available for welding between the insert made of conductive material and the inner surface of the side wall of the hollow vessel may be very limited.

[0010] Applicant noted that in order to produce a suitable weld in a very confined space, it may be necessary to resort to specific welding machines and specific welding techniques, which may result in relatively long run times and relatively high production costs.

[0011] Applicants also note that if the weld material were to accidentally peel off, it could come into contact with the electrodes of the electrochemical cell and prevent proper operation.

[0012] Applicant recognizes that batteries could be improved.

[0013] The Applicant has recognized that, in fact, after placing the lid on the hollow container, a mechanical connection must necessarily be made between the free rim of the hollow container and the free rim of the lid in order to ensure stable closure of the hollow container.

[0014] Applicants have recognised that it is possible to mechanically bond an insert of conductive material to the free rim of the hollow container, the latter being mechanically bonded to the lid.

[0015] Applicant has found that by forming the insert made of conductive material such that the free rim of the insert made of conductive material is sandwiched between the free rim of the hollow container and the free rim of the lid, electrical continuity is ensured between the insert made of conductive material, the lid, and the side wall of the hollow container by subsequent mechanical bonding of the free rim of the hollow container, the lid, and the free rim of the insert made of conductive material.

[0016] The present invention relates to a battery.

[0017] Preferably, a hollow container is provided having side and bottom walls defining an interior space.

[0018] Preferably, the hollow vessel has a top axially opposite the bottom wall.

[0019] Preferably, the hollow vessel includes an electrochemical cell inserted into the interior space thereof.

[0020] Preferably, the electrochemical cell includes an insert of conductive material that is mechanically and electrically connected to the anode of the electrochemical cell.

[0021] Preferably, the hollow container includes a lid arranged to close the top of the hollow container and including a periphery.

[0022] Preferably, the insert of electrically conductive material includes a connection portion interposed between the top of the hollow container and the periphery of the lid.

[0023] Preferably, the connecting portion of the electrically conductive material is in electrical contact with at least the upper portion of the hollow vessel.

[0024] Preferably, the periphery of the lid is in electrical contact with at least the top of the hollow vessel.

[0025] The applicant has confirmed that by interposing a connecting portion of conductive material between the top of the hollow container and the peripheral portion of the lid, such that the connecting portion of conductive material is in electrical contact with at least the top of the hollow container and the peripheral portion of the lid is in electrical contact with at least the top of the hollow container, the side wall and the lid of the hollow container can be in electrical contact with the anode of the electrochemical cell.

[0026] Applicant has also determined that this eliminates the need to weld an insert of conductive material within the cavity of the hollow vessel to the inside surface of the hollow vessel.

[0027] Applicants believe that this approach eliminates the need to rely on specific welding machines and specific welding techniques that are adapted to operate in very confined spaces.

[0028] Applicant has also discovered that there is no need to weld an insert made of conductive material to the inner surface of the hollow container, thereby preventing the weld between the conductive material and the hollow container from accidentally coming loose and reaching the electrochemical cell, thereby compromising the normal operation of the battery.

[0029] In this specification and the following claims, the term "conductive material" means a material that can carry an electric current and has a resistance of 1×10 4 This refers to materials with electrical conductivity of 1×10 at 20°C or more. 5 Siemens / meter or more, preferably 1×10 at 20°C 6 It refers to a material that has an electrical conductivity of Siemens / meter or greater.

[0030] As used in this specification and the following claims, the terms "mechanically couple" or "mechanically coupled" mean joining two or more parts or components together to form an assembly in which the parts or components are mechanically constrained.

[0031] As used in this specification and the claims that follow, the term "direct physical contact" means physical contact between two parts or components without any intervening means between the two parts or components.

[0032] As used in this specification and the claims that follow, the term "direct electrical contact" means that there is electrical continuity between two parts or components without any intervening electrically conductive means between them.

[0033] In this specification and in the claims that follow, the term "electrical contact" means electrical continuity between two parts or components. The electrical contact between the two parts or components may be direct or may have an intermediate electrical conducting means between the two parts or components.

[0034] As used herein and in the claims that follow, the terms "plastic deformation" or "plastically deformed" refer to deformation that does not disappear when the force that caused such deformation disappears.

[0035] In this specification and in the following claims, the term "cold plastic deformation" refers to a treatment of a metal carried out at a treatment temperature below 40% of the melting point of the metal being treated, preferably below 30% of the melting point of the metal being treated. For example, for a metallic material with a melting point of 1000°C, cold deformation occurs at a temperature below 400°C, preferably below 300°C.

[0036] The cell has a primary axis of deployment perpendicular to and between the other two axes of deployment. This axis is the main axis of reference of the elements that are part of the cell of the present disclosure, and in this regard, all directional and similar designations such as "axial", "radial", "circumferential" shall refer to this axis. The designations "outwards" or "internally" and "inwards" or "externally" refer to the radial direction, which should be understood as the direction away from or towards the axis.

[0037] The present invention may exhibit at least one of the preferred characteristics described below. In the battery of the present invention, these characteristics may be present individually or in combination with each other, unless otherwise specified.

[0038] Preferably, no welds are provided between the insert of electrically conductive material and the inner wall of the hollow vessel at an axial location between the bottom wall of the hollow vessel and the periphery of the lid.

[0039] Preferably, the connection portion of the insert made of electrically conductive material is in as direct electrical contact as possible with the upper portion of the hollow vessel.

[0040] Preferably, the connecting portion of the insert made of conductive material is in direct physical contact with the upper portion of the hollow vessel as much as possible.

[0041] Preferably, at least the connecting portion of the insert made of conductive material and the upper portion of the hollow container are plastically deformed to define a stable mechanical bond between the side wall of the hollow container, the lid and the insert made of conductive material.

[0042] Preferably, the connecting portion of the insert made of conductive material and the upper portion of the hollow vessel are plastically deformed so that the shape of the connecting portion of the insert made of conductive material is substantially equal to the shape of the upper portion of the hollow vessel.

[0043] Preferably, the electrochemical cell is constructed by winding a multi-layer body including a first layer of an anode material constituting the anode, a second layer of a cathode material constituting the cathode, and a third separator layer separating the anode material and the cathode material.

[0044] Preferably, the first layer of the electrochemical cell is axially offset relative to the second layer of the electrochemical cell, the first layer having an axial end facing the lid that is closer to the lid than the axial end of the second layer facing the lid.

[0045] Preferably, an axial end of the first layer of the electrochemical cell facing the lid is plastically deformed to form an anodic surface.

[0046] Preferably, the anode surface is discontinuous.

[0047] Preferably, the anode surface is uneven.

[0048] Preferably, the insert of conductive material includes a contact portion.

[0049] Preferably, said contact surface is located in a central region of an insert made of electrically conductive material.

[0050] Preferably, the connecting portion of the insert made of electrically conductive material extends axially from the contact portion towards the lid.

[0051] Preferably, the insert of electrically conductive material has a cup shape, the bottom of the cup forming the contact surface and the side walls of the cup forming the connecting portion.

[0052] Preferably, the contact portion and the connection portion are integrally formed.

[0053] Preferably, the insert of conductive material is made of copper.

[0054] Preferably, the contact portion of the insert made of conductive material is welded to the anode of the electrochemical cell.

[0055] Preferably, the contact portion of the insert of conductive material includes a plurality of fins.

[0056] Preferably, the plurality of fins are defined by notches through the conductive material.

[0057] Applicants have found that this allows the contact portion of the insert of conductive material to be axially deformable at the fin.

[0058] Preferably, each through notch is contiguous and extends along a curvilinear locus.

[0059] Preferably, the curved locus includes two side portions and a central portion, the central portion being connected to the radially outer ends of the side portions.

[0060] Preferably, the anode is welded to the insert of conductive material in at least one of the plurality of fins.

[0061] The applicant has found that by welding the anode to the at least one fin, the axial displacement (within the hollow vessel) of the insert of conductive material can be compensated for by axial deformation of the at least one fin, thereby avoiding mechanical stress on the weld between the anode and the insert of conductive material.

[0062] The applicant has also found that the deformability of the fins can compensate for the lack of uniformity of the anode surface and therefore ensure that the connecting portion of the insert made of conductive material can slightly change its spatial orientation (e.g. during plastic deformation to define a stable mechanical bond between the side wall of the hollow container, the lid and the insert made of conductive material).

[0063] Preferably, the anode is welded to the insert of conductive material in all fins of the plurality of fins.

[0064] Preferably, the hollow vessel is made of steel.

[0065] Preferably, the side and bottom walls of the hollow vessel are integrally formed.

[0066] Preferably, the hollow vessel is substantially cylindrical.

[0067] Preferably the lid is made of steel.

[0068] Preferably, the lid and the hollow container are formed from the same material.

[0069] Preferably, the lid is disc-shaped.

[0070] Preferably, the lid has a central portion from which a periphery extends radially outwardly.

[0071] Preferably, the central portion and the peripheral portion of the lid are integral.

[0072] Preferably, in the first embodiment, the connecting portion of the insert made from a conductive material is in direct electrical contact with the periphery of the lid.

[0073] In this embodiment, it is preferred to provide a weld between the lid and the upper portion of the hollow vessel.

[0074] Preferably, the welds are provided on the exterior surface of the cell.

[0075] Preferably, the weld does not directly face the interior space of the hollow vessel.

[0076] Preferably, the weld does not face the anode of the electrochemical cell.

[0077] Preferably, at least a periphery of the lid is disposed between the weld and the electrochemical cell.

[0078] Preferably, the weld seals the lid and the top of the hollow container, isolating the interior space of the hollow container from the outside environment.

[0079] Preferably, the weld also acts on the connecting portion of the insert made of electrically conductive material.

[0080] Preferably, the weld is obtained by melting the free end of the connecting portion of the insert made of electrically conductive material.

[0081] Preferably, the weld is provided between the outer surface of the lid, the free end of the upper part of the hollow container and the free end of the connecting portion of the insert made of electrically conductive material.

[0082] Applicant has found that the welds are advantageous in preventing differential thermal expansion between the conductive insert and the lid, or between the conductive insert and the hollow vessel, during charge and discharge cycles of the electrochemical cell from adversely affecting the direct electrical contact between the connection portion of the conductive insert and the top of the hollow vessel or the periphery of the lid.

[0083] Applicant has determined that this welding location does not require specific welding machines or techniques adapted to operate in very confined spaces.

[0084] Applicant has also determined that even if the weld residue breaks away from the weld, such weld residue will not reach the cavity of the hollow vessel and the electrochemical cell.

[0085] In the first embodiment, preferably the periphery of the lid does not plastically deform in defining a stable mechanical bond between the side wall of the hollow container, the lid and the insert made of conductive material.

[0086] In this embodiment, the top portion of the hollow vessel is preferably bent to form a curved portion.

[0087] Preferably, the curved portion has a recess facing radially inwards.

[0088] Preferably, the curved portion extends circumferentially along the entire upper portion of the hollow vessel forming the groove.

[0089] Preferably, the connecting portion of the insert made of conductive material is bent to form a curved portion.

[0090] Preferably, the curved portion has a recess facing radially inwards.

[0091] Preferably, said curved portion extends circumferentially along the entire connecting portion of the insert made of electrically conductive material forming the groove.

[0092] Preferably, the curved portion defined by the connecting portion of the insert of conductive material is inserted into the curved portion of the upper portion of the hollow vessel.

[0093] Preferably, the periphery of the lid is inserted into a curved portion of an insert of conductive material.

[0094] Preferably, in the second embodiment, the peripheral portion of the lid is not in direct electrical contact with the connecting portion of the insert made of conductive material.

[0095] Preferably the lid comprises an insulating layer of a material that has electrically insulating properties and protects against atmospheric agents.

[0096] Preferably, the insulating layer is disposed on the inner surface of the lid facing the interior space of the hollow vessel.

[0097] In this embodiment, the periphery of the lid is preferably overlapped over the connecting portion of the insert made of conductive material.

[0098] Preferably, the connecting portion of the insert made of conductive material is completely covered by the periphery of the lid.

[0099] Applicants have discovered that by providing an insulating layer on the inside surface of the lid and covering the periphery of the lid with the connecting portion of the insert made of conductive material, the interior of the hollow container and the electrochemical cell can be isolated from environmental factors.

[0100] In this embodiment, the connecting portion of the insert of conductive material, the top of the hollow container, and the periphery of the lid are crimped together to form an edging that is folded back on itself.

[0101] Preferably, in the edging, the upper portion of the hollow vessel is bent to form a curved portion.

[0102] Preferably, such curved portions are located on the outside of the side walls of the hollow vessel.

[0103] Preferably, such curved portion has a recess facing axially towards the bottom wall of the hollow vessel.

[0104] Preferably, such curved portion extends circumferentially around the entire upper portion of the hollow vessel and forms a groove.

[0105] Preferably, in the edging, the connecting portion of the insert made of conductive material is bent to form a curved portion.

[0106] Preferably, such curved portion has a recess facing axially towards the bottom wall of the hollow vessel.

[0107] Preferably, such curved portion extends circumferentially over the entire connecting portion of the insert of electrically conductive material forming the groove.

[0108] Preferably, the curved portion of said portion of the insert made of conductive material is superimposed on a curved portion of the upper portion of the hollow vessel.

[0109] Preferably, at the edging, the periphery of the lid is curved to form a curved portion.

[0110] Preferably, such curved portion has a recess facing axially towards the bottom wall of the hollow vessel.

[0111] Preferably, such curved portion extends circumferentially around the entire periphery of the lid, forming a groove.

[0112] Preferably, the curved periphery of the lid is overlaid on a curved portion of the insert of conductive material.

[0113] Preferably, the curved portion of the periphery of the lid includes a free end that is inserted into the curved portion of the top of the hollow container.

[0114] Preferably, the free end is straight and forms a ring that is inserted into the curved portion of the upper part of the hollow vessel.

[0115] Preferably, the periphery of the lid is in direct electrical contact with the top of the hollow vessel at the free end of the curved portion of the periphery of the lid.

[0116] Further features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments of the invention, given as illustrative and non-limiting examples, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0117] [Figure 1] FIG. 1 is a schematic cross-sectional view of a battery according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view of a battery according to a second embodiment of the present invention. [Diagram 3] FIG. 3 is an enlarged view of a detail of the battery of FIG. [Figure 4] FIG. 4 is an enlarged view of a detail of the cell of FIG. [Diagram 5] FIG. 5 is a schematic side view of the battery components of FIG. [Figure 5A] FIG. 5A is a schematic side view of the battery components of FIG. [Figure 6] FIG. 6 is a schematic top view of the components of the battery of FIGS. [Figure 7] FIG. 7 is a perspective view of further components of the battery of FIGS. [Figure 8] FIG. 8 is a schematic diagram of the assembly procedure for the battery of FIG. [Figure 9] FIG. 9 is a schematic diagram of the assembly procedure for the battery of FIG. [Figure 10] FIG. 10 is a schematic diagram of the assembly procedure for the battery of FIG. [Figure 11]FIG. 11 is a schematic diagram of the assembly procedure for the battery of FIG. [Figure 12] FIG. 12 is a schematic diagram of the assembly procedure for the battery of FIG. [Figure 13] FIG. 13 is a schematic diagram of the assembly procedure for the battery of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0118] The representation in the attached figures need not necessarily be understood to scale, nor necessarily to respect the proportions between the parts, in which identical or similar elements of different embodiments are indicated with the same reference numbers.

[0119] Batteries according to the present invention are generally designated by the reference numeral 1.

[0120] A main development axis X is defined for the battery 1. An axial direction parallel to the main development axis X, a radial direction included in a plane perpendicular to the main development axis X and passing through the main development axis X, and a circumferential direction disposed around the main development axis X and included in a plane perpendicular to the main development axis X are defined.

[0121] For ease of explanation, reference will be made explicitly to a battery 1 having a substantially cylindrical shape, with the main deployment axis X substantially coinciding with the axis of symmetry of the battery 1 .

[0122] However, the battery 1 may also have a shape different from that of a cylinder, for example a cuboid with a rectangular base.

[0123] The battery 1 includes a hollow container 2, a lid 30, an electrochemical cell 9 and an insert 15 made of a conductive material.

[0124] The hollow vessel 2 includes a side wall 3 and a bottom wall 4. The side wall 3 and the bottom wall 4 are formed from a single steel plate. The bottom wall 4 and the side wall 3 define an internal space 7 of the hollow vessel 2. The bottom wall 4 and the side wall 3 preferably have the same thickness. The thickness of the side wall 3 and the bottom wall 4 is preferably 0.1 mm or more and 1 mm or less, more preferably 0.2 mm or more and 0.5 mm or less. For example, it is 0.3 mm.

[0125] An electrode 5 is provided on the bottom wall 4 of the hollow vessel 2 and is electrically insulated from the bottom wall 4. The electrode 5 is disposed in the center of the bottom wall 4.

[0126] When the battery 1 is in an unassembled state, the hollow vessel 2 has an opening 6 opposite the bottom wall 4. The hollow vessel 2 includes a top portion 8 that faces the bottom wall 4 along an axial direction. The top portion 8 extends circumferentially around the opening 6.

[0127] In a first embodiment of the battery 1 shown in FIG. 1, the top 8 comprises a straight section 10 (axially) which, in the unassembled state of the battery 1, forms an annular extension of the side wall 3 of the hollow vessel 2 (FIG. 8). This straight section 10 is formed integrally with the side wall 3 of the hollow vessel 2. Connected to the straight section 10 is a curved section 11 which projects radially outwards and widens in the circumferential direction to form a radially enlarged section of the top 8. From the curved section 11, a straight section 12 further widens (axially) and further widens in the circumferential direction to form an annular section. The top 8 ends in a free end 13 which is also the free end of the straight section 12.

[0128] In a second embodiment of the battery 1, shown in Fig. 2, the top portion 8 comprises a straight portion 10 (axially) which, in the unassembled state of the battery 1, forms an annular extension of the side wall 3 of the hollow vessel 2 (Fig. 11). This straight portion 10 is integral with the side wall 3 of the hollow vessel 2. Connected to the straight portion 10 is a curved portion 11 which projects radially outwards and widens in the circumferential direction to form a radially enlarged portion of the top portion 8. The top portion 8 ends in a free end 13 which is also the free end of the curved portion 11.

[0129] An electrochemical cell 9, best shown in FIG. 7, includes an anode and a cathode.

[0130] The electrochemical cell 9 is of the jelly roll or Swiss roll type and includes a multi-layer body 14 wound on itself. The multi-layer body 14 includes a first layer 16 formed of an anode material that constitutes the anode of the electrochemical cell 9, and a second layer 17 formed of a cathode material that constitutes the cathode of the electrochemical cell 9. The multi-layer body 14 further includes a third separation layer (or more layers) 18 that separates the first layer 16 and the second layer 17. One skilled in the art can appropriately select the materials of the first layer 16, second layer 17, and third layer 18 to provide the electrochemical cell 9 with the desired electrical performance.

[0131] In a preferred embodiment, the first layer 16 is axially offset from the second layer 17 so as to emerge axially from the laminate 14 wound on itself. The portion of the first layer 16 which protrudes axially from the laminate 14 is plastically deformed so that the free end of the first layer 16 is bent to form an anodic surface 19. This anodic surface 19 is irregular and discontinuous and serves to increase the contact surface of the first layer 16 at the axial end of the electrochemical cell 9.

[0132] The conductive insert 15 is preferably made of copper. As best shown in Figures 5, 5A, and 6 (when the conductive insert 15 is not yet assembled into the battery 1), the conductive insert 15 has a shape along a cross section perpendicular to the axial direction that substantially matches the shape of the bottom wall 4 of the hollow vessel 2. In this embodiment, the conductive insert 15 has a shape along a cross section perpendicular to the axial direction that is substantially circular.

[0133] The insert 15 of conductive material includes a substantially planar contact portion 20. The insert 15 of conductive material further includes a connecting portion 21. The connecting portion 21 projects axially from a radial end of the contact portion 20 and extends axially away from the contact portion 20.

[0134] The contact portion 20 is provided with a number of fins 22. Each fin 22 is defined by a through notch 23 passing axially through the contact portion 20. Each through notch 23 follows a curved path consisting of two side portions 24 and a central portion 25 (FIG. 6). From the central region of the contact portion 20 to the peripheral region of the contact portion 20, the side portions 24 extend along respective radial directions. The central portion 25 connects the two side portions 24 and extends substantially in the circumferential direction. As shown diagrammatically in FIG. 6, each fin 22 is substantially petal-shaped and can be raised in the axial direction by rotating about a virtual hinge axis that joins the free ends of the two side portions 24 of the notch 23. The fins 22 are preferably greater than or equal to 2 and less than or equal to 8. For example, the fin 18 has four.

[0135] Figure 5 shows a side view of the insert 15 (unassembled) made of conductive material of the first embodiment of the battery shown in figure 1. In this embodiment, the connection part 17 comprises a straight part 26 (axially) which widens in the circumferential direction to form an annular part. The straight part 26 is directly connected to the contact part 20. Connected to the straight part 26 is a curved part 27 which projects radially outwards and widens in the circumferential direction to form a radially enlarged part of the upper part 17. From the curved part 27 a further straight part 28 widens (axially) which widens in the circumferential direction to form a further annular part. The connection part 17 ends in a free end 29 which is also the free end of the further straight part 28.

[0136] 5A shows a side view of the insert 15 (in an unassembled state) made of a conductive material of a second embodiment of the battery shown in FIG. 2. In this embodiment, the connection portion 17 comprises a straight portion 26 (in the axial direction) which widens in the circumferential direction to form an annular portion. The straight portion 26 is directly connected to the contact portion 20. Connected to the straight portion 26 is a curved portion 27 which projects radially outward and widens in the circumferential direction to form a radially enlarged portion of the upper portion 17. The connection portion 17 ends in a free end 29 which is also the free end of the curved portion 27.

[0137] The lid 30 is made of steel. The lid 30 has a cross-sectional shape perpendicular to the axial direction that substantially corresponds to the shape of the bottom wall 4 of the hollow vessel 2. In the illustrated embodiment, the cross-sectional shape perpendicular to the axial direction of the lid 30 is substantially circular.

[0138] The lid may include one or more reinforcing ribs. The lid 30 includes a peripheral portion 31 radially surrounding a central portion 30a.

[0139] In the first embodiment of the battery 1 shown in Figure 1, the peripheral portion 31 includes a linear portion 32 (Figure 9) that extends radially when the battery 1 is in an unassembled state. The peripheral portion 31 terminates in a free end 33, which is also a free end of the linear portion 32.

[0140] In a second embodiment of the battery 1 shown in Fig. 2, the peripheral portion 31 includes an axially straight portion 34 (in the axial direction) which forms an annular shoulder when the battery 1 is in an unassembled state (Fig. 12). Connected to the straight portion 34 is a radially straight portion 35 (in the radial direction) which projects radially and extends circumferentially around the entire peripheral portion 31. From the radially straight portion 35 extends further an axially straight portion 36 (in the axial direction) which extends circumferentially to form an annular portion. The peripheral portion 31 ends in a free end 37 which is also the free end of the axially straight portion 36.

[0141] In this embodiment, the lid 30 includes an insulating layer 38 (shown diagrammatically as shown in FIG. 4) of a material that has electrical insulating properties and protection from atmospheric agents.

[0142] The insulating layer 38 is disposed on the inside of the lid 30 so as to face the interior space 7 of the hollow vessel 2 .

[0143] For example, insulating layer 38 may be a polyurethane lacquer that has a dielectric constant less than 4.0 and is resistant to moisture and salt vapor.

[0144] In the assembled state of the battery 1, the electrochemical cell 9 is inserted into the interior space 7 of the hollow vessel 2 with the cathode facing towards the bottom wall 4. The cathode is electrically connected to the electrode 5. In particular, the second layer 17 of the multi-layer body 14 is electrically connected to the electrode 5 arranged on the bottom wall 4 of the hollow vessel 2.

[0145] The anode is electrically connected to the insert 15 made of conductive material by welding the contact portion 20 to the anode. In particular, the anode face 19 is welded to the fins 22 of the contact portion 20 of the insert 15 made of conductive material.

[0146] In both embodiments, the connecting portion 21 of the insert 15 made of conductive material is interposed between the top portion 8 of the hollow container 2 and the peripheral portion 31 of the lid 30, as shown diagrammatically in Figures 3 and 4 which show the assembled battery 1 in the two embodiments.

[0147] The connecting portion 21 of the insert 15 made of electrically conductive material is in electrical contact with the top portion 8 of the hollow vessel 2 , and the peripheral portion 31 of the lid 30 is in direct electrical contact with the top portion 8 of the hollow vessel 2 .

[0148] The connecting portion 21 of the insert 15 made of electrically conductive material is in direct physical contact with the top portion 8 of the hollow vessel 2 .

[0149] The connecting portion 21 of the insert 15 made of conductive material is further in direct physical contact with the periphery 31 of the lid 30 .

[0150] The connecting portion 21 of the insert 15 made of conductive material and the top portion 8 of the hollow container 2 are plastically deformed to create a stable mechanical bond between the side wall 3, the lid 30 and the insert 15 made of conductive material.

[0151] In the first embodiment of the battery 1 shown in FIG. 1 and in the enlarged view of FIG. 3, the connecting portion 21 of the insert 15 made of conductive material is in direct electrical and physical contact with the peripheral portion 31 of the lid 30.

[0152] In this embodiment, the top portion 8 of the hollow vessel 2 is plastically deformed to form a curved portion 40 defined between a curved portion 11 and a further straight portion 12 .

[0153] The connecting portion 21 of the insert 15 made of a conductive material is disposed radially inside the upper portion 8 of the hollow container 2. As shown in FIG. 3, the connecting portion 21 of the insert 15 made of a conductive material is included in a part of the curved portion 40.

[0154] At this point, the connection portion 21 of the insert 15 made of electrically conductive material is plastically deformed to form a curved portion 41 defined between the curved portion 27 and the further straight portion 28 .

[0155] The curved portion 41 of the connecting portion 21 of the insert 15 made of conductive material is inserted into the curved portion 40 of the top portion 8 of the hollow container 2 and receives the peripheral portion 31 of the lid 30. The peripheral portion 31 of the lid 30 does not bend or deform plastically.

[0156] As shown in Fig. 3, the free end 13 of the upper part 8 of the hollow vessel 2 substantially faces the lid 30 in the radial direction. A weld 42 is provided between the free end 13 of the upper part 8 of the hollow vessel 2 and the lid 30. Such a weld 42 also affects the free end 29 of the connection part 21 of the insert 15 made of electrically conductive material.

[0157] In the second embodiment of the battery 1 shown in FIG. 2 and in the enlarged view of FIG. 4, the peripheral portion 31 of the lid 30 is not in direct electrical contact with the connection portion 21 of the insert 15 made of a conductive material.

[0158] Also, in this embodiment, the peripheral portion 31 of the lid 30 is in direct physical contact with the connecting portion 21 of the insert 15 made of conductive material. In particular, the peripheral portion 31 of the lid 30 is in direct contact with the connecting portion 21 of the insert 15 made of conductive material via the insulating layer 38.

[0159] In this embodiment, the top portion 8 of the hollow vessel 2 is plastically deformed to form a curved portion 43 defined by the curved portion 11 .

[0160] The connecting portion 21 of the insert 15 made of a conductive material overlaps with the upper portion 8 of the hollow container 2. As shown in FIG. 4, the connecting portion 21 of the insert 15 made of a conductive material overlaps the outside of the curved portion 43.

[0161] At this point, the connecting portion 21 of the insert 15 made of conductive material is plastically deformed to form a curved portion 44 defined by the curved portion 27 .

[0162] The curved portion 44 of the connecting portion 21 of the insert 15 made of electrically conductive material includes the curved portion 43 of the upper portion 8 of the hollow vessel 2 .

[0163] The periphery 31 of the lid 30 at least partially overlaps the connecting portion 21 of the insert 15 made of conductive material. The periphery 31 of the lid 30 overlaps the outside of the curved portion 44 of the connecting portion 21 of the insert 15 made of conductive material.

[0164] At this point, the periphery 31 of the lid 30 is plastically deformed to form a curved portion 45 defined by the radial straight portions 35. The curved portion 45 of the periphery 31 of the lid 30 includes a curved portion 44 of the connecting portion 21 of the insert 15 made of conductive material.

[0165] 3, the free end 37 of the peripheral portion 31 of the lid 30 is inserted into the curved portion 43 of the top portion 8 of the hollow container 2. The free end 37 of the peripheral portion 31 of the lid 30 is in direct physical and direct electrical contact with the top portion 8 of the hollow container 2.

[0166] At this point, the peripheral portion 31 of the lid 30 is plastically deformed to form a further curved portion 46 in the further axial straight portion 36. This further curved portion 46 includes the free end 13 of the top portion 8 of the hollow vessel 2.

[0167] To assemble the battery 1, in both embodiments, provision is made for providing the hollow container 2, the lid 30, the insert 15 made of conductive material and the electrochemical cell 9 as elements separate from one another.

[0168] It is then envisaged that an insert 15 made of a conductive material is mechanically and electrically connected to the anode of the electrochemical cell 9 .

[0169] This operation is carried out by welding an anode to the contact portion 14 of the insert 15 made of conductive material. In particular, it is envisaged to weld the anode surface 19 to all fins 22 of the contact portion 20 of the insert 15 made of conductive material.

[0170] The assembly consisting of the electrochemical cell 9 and an insert 15 made of conductive material is then inserted into the interior space 7 of the hollow vessel 2 with the anode facing the top 8 of the hollow vessel 2 .

[0171] A connecting portion 21 of the insert 15 made of electrically conductive material is arranged in direct electrical and physical contact with the upper portion 8 of the hollow vessel 2 .

[0172] This is carried out by at least partially overlapping the connecting portion 21 of the insert 15 made of electrically conductive material onto the upper portion 8 of the hollow vessel 2 .

[0173] According to the first embodiment, as shown in Fig. 8, the connection portion 21 of the insert 15 made of conductive material is placed on the upper part 8 of the hollow vessel 2 such that the curved portion 27 of the connection portion 21 overlaps with the curved portion 11 of the upper part 8 of the hollow vessel 2. The further straight portion 28 of the connection portion 21 is placed opposite the further straight portion 12 of the upper part 8 of the hollow vessel 2. The straight portion 28 of the connection portion 21 is placed on the straight portion 10 of the upper part 8 of the hollow vessel 2.

[0174] The connecting portion 21 of the insert 15 made of electrically conductive material is completely received radially within the upper portion 8 of the hollow vessel 2 .

[0175] 11 , the connection portion 21 of the insert 15 made of conductive material is placed on the upper portion 8 of the hollow vessel 2 such that the curved portion 27 of the connection portion 21 overlaps with the curved portion 11 of the upper portion 8 of the hollow vessel 2. The straight portion 28 of the connection portion 21 is placed on the straight portion 10 of the upper portion 8 of the hollow vessel 2.

[0176] The connecting portion 21 of the insert 15 made of electrically conductive material is arranged radially inside the upper portion 8 of the hollow vessel 2 .

[0177] In both embodiments it is then envisaged that the peripheral portion 31 of the lid 30 is placed in direct physical contact with the connecting portion 21 of the insert 15 made of conductive material.

[0178] This operation envisages at least partially overlapping the peripheral portion 31 of the lid 30 with the connecting portion 21 of the insert made of conductive material.

[0179] In the first embodiment, as shown in FIG. 9, the peripheral portion 31 of the lid 30 is positioned on the connection portion 21 of the insert 15 made of a conductive material, so that the straight portion 32 of the peripheral portion overlaps with the curved portion 27 of the connection portion 21.

[0180] According to the second embodiment, as shown in Fig. 12, the peripheral portion 31 of the lid 30 is placed on the connecting portion 21 of the insert 15 made of conductive material, with the radial straight portion 35 of the peripheral portion 31 overlapping the curved portion 27 of the connecting portion 21. A further axial straight portion 36 of the peripheral portion 31 is located radially outside the connecting portion 21 of the insert 15 made of conductive material. An axial straight portion 34 of the peripheral portion 31 is placed on the straight portion 26 of the connecting portion 21 of the insert 15 made of conductive material.

[0181] In both embodiments, it is then envisaged that the connecting portion 21 of the insert 15 made of conductive material is mechanically joined to the upper portion 8 of the hollow container 2 and the peripheral portion 31 of the lid 30, so that the peripheral portion 31 of the lid 30 is in electrical contact with the upper portion 8 of the hollow container 2.

[0182] This operation is carried out by cold plastic deformation of at least the connection portion 21 of the insert 15 made of electrically conductive material and of the upper portion 8 of the hollow vessel 2 .

[0183] According to the first embodiment, only the connection portion 21 of the insert 15 made of conductive material and the upper portion 8 of the hollow vessel 2 are plastically deformed, as shown in FIG.

[0184] Such deformation envisages plastic deformation of the connecting portion 21 of the insert 15 made of conductive material to form the curved portion 41. By the same plastic deformation operation, the upper portion 8 of the hollow container 2 is also plastically deformed to form the curved portion 40. Thus, the curved portion 41 of the connecting portion 21 and the curved portion 40 of the upper portion 8 are formed simultaneously.

[0185] Due to plastic deformation of the connection portion 21 of the insert 15 made of a conductive material and the connection portion of the upper portion 8 of the hollow container 2, the peripheral portion 31 of the lid 30 is permanently restrained to the container 2, so that the peripheral portion 31 of the lid 30 is in direct and permanent electrical contact with the upper portion 8 of the hollow container 2 (and the connection portion 21 of the insert 15 made of a conductive material).

[0186] The plastic deformation of the connecting portion 21 of the insert 15 made of electrically conductive material and the top portion 8 of the hollow vessel 2 is performed by simultaneously cold bending the further straight portion 12 of the top portion 8 and the further straight portion 28 of the connecting portion 21 onto the peripheral portion 31 of the lid 30. Due to the plastic deformation of the connecting portion 21 of the insert 15 made of electrically conductive material and the top portion 8 of the hollow vessel 2, the free end 29 of the connecting portion 21 is radially positioned between the lid 30 and the free end 13 of the top portion 8.

[0187] It is envisaged that the connecting portion 21 of the insert 15 made of a conductive material is welded to the lid 30 and to the upper portion 8 of the hollow container 2, although a mechanical bond between the connecting portion 21 of the insert 15 made of a conductive material, the upper portion 8 of the hollow container 2 and the peripheral portion 31 of the lid 30 places the peripheral portion 31 of the lid 30 in electrical contact with the upper portion 8 of the hollow container 2 (thus enabling normal operation of the battery 1).

[0188] This operation envisages welding the free end 29 of the connecting part 15 of the insert 15 made of conductive material to the outer surface of the lid 30 and to the free end 13 of the top part 8 of the hollow vessel 2. The welding is carried out by melting the free end 29 of the connecting part 15 of the insert 15 made of conductive material. This welding also seals the interior space 7 of the hollow vessel 2 in a liquid-tight manner.

[0189] This completes the assembly of the battery 1 of the first embodiment.

[0190] According to the second embodiment, as shown in FIG. 13 (and also seen in FIG. 4), both the connection portion 21 of the insert 15 made of conductive material and the upper portion 8 of the hollow container 2 and the peripheral portion 31 of the lid 30 are plastically deformed.

[0191] Such deformation envisages plastic deformation of the connection portion 21 of the insert 15 made of conductive material to form a curved portion 44. By the same plastic deformation operation, the upper portion 8 of the hollow container 2 is also plastically deformed to form a curved portion 43. By the same plastic deformation operation, the peripheral portion 31 of the lid 30 is also plastically deformed to form a curved portion 45. Thus, the curved portion 44 of the connection portion 21, the curved portion 43 of the upper portion 8 and the curved portion 45 of the peripheral portion 31 are formed simultaneously.

[0192] Further, a further curved portion 46 of the periphery 31 of the lid is formed by the same plastic deformation operation. As a result, the further curved portion 46 of the periphery 31 is also formed at the same time as the curved portion 45 of the periphery 31.

[0193] Due to plastic deformation of the connection portion 21 of the insert 15 made of a conductive material, the upper portion 8 of the hollow container 2, and the peripheral portion 31 of the lid 30, the peripheral portion 31 of the lid 30 is permanently restrained to the container 2, and the peripheral portion 31 of the lid 30 is in direct and permanent electrical contact with the upper portion 8 of the hollow container 2 (and the connection portion 21 of the insert 15 made of a conductive material is also in direct and permanent electrical contact with the upper portion 8 of the hollow container 2).

[0194] The plastic deformation of the connecting portion 21 of the insert 15 made of conductive material, the top portion 8 of the hollow container 2 and the peripheral portion 31 of the lid 30 is carried out by crimping to form a folded edging 47 .

[0195] Crimping is a cold plastic deformation process used to join the edges of thin-walled metal sheets. The resulting joint is fluid-tight for containers closed by such a process. The crimp used is the so-called "double seam" crimp, formed by mechanically interlocking at least six layers of material. In the case of the second embodiment, these layers are seven, consisting of two layers formed by the connecting portion 21 of the insert 15 made of conductive material, two layers created by the top 8 of the hollow container 2, and three layers created by the peripheral portion 31 of the lid 30, as shown in FIG. 4.

[0196] The smaller or larger size of the portion 21 may be 6 or 8 layers, respectively (in the latter case, the portion 21 may be further bent together with the lid 30).

[0197] The plastic deformation of the connecting portion 21 of the insert 15 made of conductive material, the upper portion 8 of the hollow container 2 and the peripheral portion 31 of the lid 30 is carried out by cold bending the free end 37 of the peripheral portion 31 of the lid 30 onto the free end 13 of the upper portion 8 of the hollow container 2 and cold bending the assembly formed by the free end 37 of the peripheral portion 31, the free end 13 of the upper portion 8, the radial straight portion 35 of the peripheral portion 31 and the free end 29 of the connecting portion 21 to bring them into contact with the side wall 3 of the hollow container 2.

[0198] This completes the assembly of the battery 1 of the second embodiment.

Claims

1. A hollow vessel (2) having a side wall (3) and a bottom wall (4) defining an interior space (7), with an upper portion (8) facing the bottom wall (4) along an axial direction; an electrochemical cell (9) inserted into the internal space (7) of the hollow vessel (2); an insert (15) made of a conductive material mechanically and electrically connected to the anode of the electrochemical cell (9); a lid (30) arranged to close the hollow container (2) at the top (8) and having a periphery (31); the insert (15) made of conductive material is interposed between the upper part (8) of the hollow container (2) and the peripheral part (31) of the lid (30), and has a connection part (21) in electrical contact with at least the upper part (8) of the hollow container (2), and the peripheral part (31) of the lid (30) is in electrical contact with at least the upper part (8) of the hollow container (2); Battery (1).

2. the connecting portion (21) of the insert (15) made of conductive material is in direct electrical contact with the top portion (8) of the hollow vessel (2); 2. The battery (1) according to claim 1.

3. at least said connecting portion (21) of said insert (15) made of conductive material and said top portion (8) of said hollow container (2) are plastically deformed to define a stable mechanical connection between said side wall (3) of said hollow container (2), said lid (30) and said insert (15) made of conductive material; 3. The battery (1) according to claim 2.

4. the insert (15) made of conductive material has a contact portion (20) welded to the anode of the electrochemical cell (9), and the connection portion (21) extends axially from the contact portion (20) towards the lid (30); A battery (1) according to any one of claims 1 to 3.

5. The contact portion (20) of the insert (15) of conductive material includes a plurality of fins (22) defined by notches (23) extending through the insert (15) of conductive material.

5. The battery (1) according to claim 4.

6. the anode is welded to the insert (15) made of conductive material in at least one fin (22) of the plurality of fins (22); 6. The battery (1) according to claim 5.

7. a weld (42) acting between the lid (30) and the top (8) of the hollow vessel (2), the weld (42) being provided on the outer surface of the battery (1); A battery (1) according to any one of the preceding claims.

8. the weld (42) additionally acts on the connection portion (21) of the insert (15) made of conductive material; 8. The battery (1) according to claim 7.

9. the weld (42) being provided between the outer surface of the lid (30), the free end (13) of the top (8) of the hollow container (2) and the free end (29) of the connecting portion (21) of the insert (15) made of conductive material; 9. The battery (1) according to claim 8.

10. The weld (42) seals the lid (30) and the top (8) of the hollow vessel (2) together and isolates the interior space (7) of the hollow vessel (2) from the outside environment. A battery (1) according to any one of claims 7 to 9.

11. the peripheral portion (31) of the lid (30) does not plastically deform in defining a stable mechanical connection between the side wall (3) of the hollow container (2), the lid (30) and the insert made of conductive material; A battery (1) according to any one of the preceding claims.

12. the upper portion (8) of the hollow container (2) is bent to form a curved portion (40), the connecting portion (21) of the insert (15) made of conductive material is bent to form a curved portion (41) inserted into the curved portion (40), and the peripheral portion (31) of the lid (30) is inserted into the curved portion (41) of the insert (15) made of conductive material; A battery (1) according to any one of claims 1 to 11.

13. the connecting portion (21) of the insert (15) made of conductive material, the top portion (8) of the hollow container (2) and the peripheral portion (31) of the lid (30) are crimped together to form a folded edging (47); A battery (1) according to any one of the preceding claims.

14. In the edging (47), the upper portion (8) of the hollow vessel (2) is bent to form a curved portion (43); the connecting portion (21) of the insert (15) made of conductive material is bent to form a curved portion (44) superimposed on the curved portion (43) of the upper portion (8) of the hollow container (2); the peripheral portion (31) of the lid (30) is bent to form a curved portion (45) that overlaps the curved portion (44) of the insert (15) made of conductive material; a free end (37) inserted into the curved portion (43) of the upper portion (8) of the hollow vessel (2); 14. The battery (1) according to claim 13.

15. said lid (30) comprising an insulating layer (38) of a material having electrical insulating properties and protection against atmospheric agents, said insulating layer (38) being arranged on the inner surface of said lid (30) facing the interior space (7) of the hollow container (2); 15. A battery (1) according to claim 13 or 14.

Images