ENERGY STORAGE ELEMENT, ENERGY STORAGE ELEMENT ASSEMBLY, AND METHOD OF MANUFACTURING - Patent application
Patent Information
- Application Number
- JP2023577352
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2021-09-10
- Filing Date
- 2022-07-20
- Publication Date
- 2025-06-26
AI Technical Summary
Existing lithium-ion cells, particularly those designed for high energy applications, suffer from suboptimal energy density and reliability issues, including dead volumes that reduce energy efficiency and doubts about overpressure protection.
The design incorporates a sealed housing with a metal cup-shaped portion and a lid component, featuring terminal poles made of different metallic materials for easy integration into cell assemblies, and includes a contact sheet metal member welded to the anode current collector, ensuring efficient electrical contact and improved safety through overpressure protection.
The solution enhances energy density and safety by minimizing dead volumes and providing reliable overpressure protection, allowing for efficient processing into cell assemblies with improved current carrying capacity and thermal management.
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Abstract
Description
[Technical field]
[0001] The inventions described below relate to energy storage elements, assemblies of energy storage elements, and methods of manufacture. [Background technology]
[0002] Electrochemical energy storage elements can convert stored chemical energy into electrical energy due to redox reactions. The simplest form of electrochemical energy storage element is an electrochemical cell. It includes a positive and a negative electrode separated by a separator. During discharge, electrons are released at the negative electrode as a result of an oxidation process. This results in an electron flow that can be extracted by an external electrical consumer, where the electrochemical cell acts as an energy supplier. At the same time, an ionic current corresponding to the electrode reactions is generated in the cell. This ionic current crosses the separator and is enabled by an ion-conducting electrolyte.
[0003] If the discharge is reversible, i.e., the conversion of chemical energy to electrical energy that occurs during discharge can be reversed and the cell can be charged again, it is called a secondary cell. The designation of the negative electrode as the anode and the positive electrode as the cathode, commonly used for secondary cells, is referred to as the discharge function of the electrochemical cell.
[0004] Secondary lithium-ion cells are used as energy storage elements for many applications, since they can provide large currents and are characterized by a relatively high energy density. They are based on the use of lithium, which can be transferred in the form of ions between the electrodes of the cell. The negative and positive electrodes of lithium-ion cells are generally formed by so-called composite electrodes, which contain electrochemically active and electrochemically inactive components.
[0005] In principle, all materials that can absorb and release lithium ions can be used as electrochemically active components (active materials) for secondary lithium-ion cells. For the negative electrode, for example, carbon-based particles, such as graphitic carbon, are used. For the positive electrode, the active material can be, for example, lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), lithium iron phosphate (LiFePO4) or derivatives thereof. The electrochemically active material is generally included in the electrode in the form of particles.
[0006] As electrochemically inactive components, composite electrodes generally include flat and / or ribbon-shaped current collectors, e.g., metal foils, which serve as carriers for the respective active materials. The current collector for the negative electrode (anode current collector) may be formed, for example, of copper or nickel, and the current collector for the positive electrode (cathode current collector) may be formed, for example, of aluminum. In addition, the electrodes may include an electrode binder (e.g., polyvinylidene fluoride (PVDF) or another polymer, e.g., carboxymethyl cellulose), conductivity enhancing additives, and other additives as electrochemically inactive components. The electrode binder ensures the mechanical stability of the electrode and often the adhesion of the active material to the current collector.
[0007] As an electrolyte, lithium-ion cells generally contain a solution of a lithium salt, such as lithium hexafluorophosphate (LiPF6), in an organic solvent (e.g., ethers and esters of carbonic acid).
[0008] In the manufacture of lithium-ion cells, the composite electrodes are combined with one or more separators to form an assembly. In this process, the electrodes and separators are connected, usually under pressure, possibly by lamination or by bonding. Basic functionality of the cell can then be established by impregnating the assembly with an electrolyte.
[0009] In many embodiments, the assembly is formed or wound as a winding. Typically, it comprises a positive electrode / separator / negative electrode sequence. Often, the assembly is made as a so-called bicell, with possible sequences of negative electrode / separator / positive electrode / separator / negative electrode or positive electrode / separator / negative electrode / separator / positive electrode.
[0010] For applications in the automotive sector, for electric bicycles or other applications with similarly high energy requirements, for example in tools, lithium-ion cells are required which have the highest possible energy density and at the same time are capable of carrying high currents during charging and discharging.
[0011] Cells for the mentioned applications are often designed as cylindrical round cells, for example with a form factor of 21x70 (diameter*height in mm). This type of cell always includes an assembly in the form of a winding. Modern lithium-ion cells of this form factor can already achieve an energy density of up to 270Wh / kg. However, this energy density is only considered as an intermediate step. The market is already demanding cells with even higher energy density.
[0012] WO 2017 / 215900 A1 describes an electrode separator assembly and a cylindrical circular cell whose electrodes are ribbon-shaped and in the form of a winding. The electrodes each have a current collector loaded with electrode material. The oppositely polarized electrodes are arranged offset from each other in the electrode separator assembly, such that the longitudinal edge of the positive current collector protrudes from the winding on one side and the longitudinal edge of the negative current collector protrudes from the winding on the other side. For electrical contact of the current collectors, the cell has a contact plate that is mounted on the end face of the winding and connected to one longitudinal edge of the current collector by welding. This allows the current collector and therefore also the associated electrode to be electrically contacted over its entire length. This significantly reduces the internal resistance in the described cell. The generation of large currents can then be absorbed much better and heat can also be better diffused from the winding.
[0013] Cylindrical round cells, such as those in WO 2017 / 215900 A1, are usually used as part of a cell assembly in which several cells are connected together in series and / or parallel. It is often desirable to contact the cells at only one of their end faces to extract a voltage. It is therefore advantageous to provide at one of the end faces both a terminal connected to the positive pole of the cell and a terminal connected to the negative pole of the cell.
[0014] From US 2006 / 0019150 A1 a lithium ion circular cell is known which comprises an electrode separator assembly in a cylindrical housing, the electrode separator assembly being formed as a winding. The housing comprises a cylindrical metal housing cup whose opening is closed by a metal lid component. The bottom of the housing cup is electrically connected to the positive pole of the winding, the housing cup therefore being positively polarised. Both housing parts are in direct contact with each other, so that the lid component is also positively polarised. A positive metal connection pole is welded to the lid component. The negative pole of the winding is on the other hand connected to a negative metal terminal pole, which is threaded through an aperture in the lid component and electrically insulated from it. The positive and negative connection poles are therefore arranged next to each other on the same side of the cell, so that the cell can be easily integrated into the cell assembly via corresponding current conductors.
[0015] In addition to its good contact, the cell described in US 2006 / 0019150 A1 also features an integrated overpressure protection. For this purpose, the bottom has a central, circular area separated from the annular remaining area of the bottom by a circumferential weakening line and into which a curved conductor strip is welded, through which said electrical contact from the bottom to the positive pole of the winding is made. In case of overpressure inside the housing, the circular area can be blown off from the bottom. The annular insulator ensures that the annular remaining area does not come into contact with the wound electrode separator assembly in any way, so that electrical contact between the positive pole and the annular remaining area and all components in electrical contact with them, including the positive terminal pole, is thereby broken.
[0016] The negative pole of the winding is electrically contacted via a plurality of curved conductive strips having upper ends bonded to the negative terminal pole.
[0017] From an energy point of view, the design of the cell described in US 2006 / 0019150 A1 is not optimal. There is dead volume at both ends of the winding, which the aforementioned conductor strip is required to fill. This has a negative impact on the energy density of the cell. Furthermore, there are doubts about the reliability of the overpressure protection. If the weakened line does not tear over its entire length when the overpressure protection is triggered, the electrical connection to the positive terminal pole is not completely broken and the current can continue to flow. Summary of the Invention [Problem to be solved by the invention]
[0018] It was an object of the present invention to provide an energy storage element which is characterized by an improved energy density compared to the prior art and which can be efficiently processed to form cell assemblies. Moreover, the energy storage element should also be characterized by an improved safety. [Means for solving the problem]
[0019] This object is achieved by an energy storage element as described below. An assembly of the energy storage element as described below and a manufacturing process as described below are also subject of the present invention. Particularly preferred embodiments of the energy storage element according to the invention, the assembly according to the invention and the method according to the invention are defined in independent claims 1, 8 and 9. Preferred embodiments of the invention can be found in claims 2 to 7.
[0020] Energy storage element according to the present invention The energy storage element according to the invention has the following characteristics a. to l.: It includes an air-tight and liquid-tight sealed housing and an electrode separator assembly disposed therein. b. The housing includes a metal cup-shaped housing portion including a housing bottom and a terminal opening. c. the housing includes a lid component welded to and closing the terminal opening in the cup-shaped housing portion; d. A lid component includes a metal lid plate and a terminal pole that is threaded through an aperture in the lid plate and is electrically insulated from the lid plate. e. The electrode separator assembly includes first and second terminal flat end faces. f. An electrode separator assembly includes an anode with an anode current collector having a first edge and a parallel second edge. g. An anode current collector including a main area carrying a layer of negative electrode material and a free edge strip extending along a first edge thereof free of electrode material. h. An electrode separator assembly includes a cathode having a cathode current collector having a first edge and a parallel second edge. i. a cathode current collector including a main area carrying a layer of positive electrode material and a free edge strip extending along a first edge thereof that does not carry electrode material; j. The anode and cathode are positioned within the electrode separator assembly such that a first edge of the anode current collector protrudes from a first terminal end face and a first edge of the cathode current collector protrudes from a second terminal end face of the electrode separator assembly. k. The energy storage element includes a contact sheet metal member mounted to the first edge of the anode current collector and connected thereto by welding. l. The contact sheet metal member is electrically connected to a terminal pole which passes through an aperture in the lid plate.
[0021] Particularly preferably, the energy storage element having the characteristics a. to l. has the following additional characteristics m. and n.: m. The terminal pole includes a first contact portion made of nickel or copper or titanium or nickel alloy or copper alloy or titanium alloy or stainless steel and a second contact portion made of aluminum or aluminum alloy. n. The second contact portion may be mechanically contacted from outside the housing.
[0022] The energy storage element according to the invention is therefore particularly preferably characterized by a terminal pole comprising two different metallic materials, nickel or copper or titanium or a nickel alloy or a copper alloy or a titanium alloy or a stainless steel on one side and aluminium or an aluminium alloy on the other side, and which is electrically connected to the anode current collector via a contact sheet metal member, so that the terminal pole is a negative terminal pole.
[0023] Energy storage elements with such negative terminals offer the considerable advantage that they can be easily integrated into a cell assembly. The poles of several energy storage elements are interconnected via a common current conductor. In terms of manufacturing techniques, it can be advantageous to weld the poles of the cells to the current conductor by laser. Generally, this is problem-free only if the materials to be welded are the same. For example, it is difficult or impossible to weld a terminal pole made of copper to a current conductor made of aluminum using a laser. On the other hand, with a second contact part made of aluminum or an aluminum alloy, this is possible without problems. Thus, even the negative connection poles of the cells can be connected via a common current conductor by laser.
[0024] It is particularly preferred that the terminal pole comprises a first contact portion made of nickel or copper or a nickel alloy or a copper alloy or a stainless steel and a second contact portion made of aluminium or an aluminium alloy.
[0025] Suitable aluminum alloys are, for example, Al alloys of types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series) and GM55. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg and AlMg. The aluminum content of said alloys is preferably more than 99.5%. Suitable stainless steels are, for example, stainless steels of type 1.4303 or 1.4404 or of type SUS304 or nickel-plated steels. In particular, materials of type ENCW-004A or ENCW-008A with a copper content of at least 99.9% can be used as copper alloys. Nickel alloys of type NiFe, NiCu, CuNi, NiCr and NiCrFe are particularly suitable.
[0026] Aluminum Housing In a particularly preferred embodiment of the invention, the energy storage element according to the invention always has at least one of the following characteristics a. to d.: The cup-shaped housing portion is made of aluminum or aluminum alloy. b. The cover plate is made of aluminum or an aluminum alloy. c. The lid component includes a separate terminal pole fixed to the lid plate, in particular welded to the lid plate, and made of aluminum or an aluminum alloy. d. The cup-shaped housing portion and the cover plate and the separate terminal pole are made of aluminum or an aluminum alloy. It is preferred that the immediately preceding features a. and b., and particularly preferred also features a. to c. and a. to d., are realised in combination.
[0027] In this embodiment, the housing of the energy storage element consists essentially entirely of aluminum or an aluminum alloy (with the exception of the negative terminal and its insulation). This has various advantages: the formation of localized elements in case of contact with moisture outside the cell is eliminated. The housing itself can essentially function as the positive connection pole on all its sides. However, it is particularly preferred that the cell is exclusively connected via the lid component, in which the negative terminal pole is also located. For this purpose, the electrical conductor can be welded directly to the lid plate or alternatively fixed, for example by welding, to a separate connection pole. In this case, the separate connection pole is the positive connection pole.
[0028] Suitable aluminum alloys for the cup-shaped housing part and the lid plate are, for example, Al alloys of type 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series) and GM55. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg and AlMg. The aluminum content of said alloys is preferably greater than 99.5%.
[0029] In a preferred embodiment, the energy storage element according to the present invention is a prismatic or circular cell.
[0030] Square-shaped embodiment In this embodiment, the housing is angular. In this embodiment, the cup-shaped housing part and the bottom of the lid component preferably have a polygonal, particularly preferably rectangular, base. The shape of the terminal opening of the cup-shaped housing part corresponds to the shape of the bottom and the lid component. Furthermore, the housing has a plurality of, preferably four, rectangular side portions interconnecting the bottom and the lid component. In this embodiment, the electrode separator assembly is also preferably angular in shape. In this case, the electrode separator assembly is preferably a angular stack comprising a plurality of anodes, cathodes and at least one separator, the electrode separator assembly in the stack always having a series of anodes / separators / cathode.
[0031] At least the anode and cathode preferably have a rectangular base area, and the current collectors of the anode and cathode each have a first edge and a parallel second edge, and each have a free edge strip along their first edge that is not coated with the respective electrode material. If there are multiple separators between the anode and cathode, the separators also preferably have a rectangular base. However, it is also possible that ribbon-shaped separators are used to separate multiple anodes and cathodes in a stack.
[0032] For example, the first and second terminal planar end faces of the stack are two opposite or adjacent sides of the stack. A first edge of the anode current collector projects from one of these end faces and a first edge of the cathode current collector projects from the other. A contact sheet metal member is on the first edge of the anode current collector and is connected thereto by welding.
[0033] Cylindrical Circular Cells In this embodiment of the invention, the energy storage element according to the invention preferably has a combination of the immediately following characteristics a. to o.: a. The shape of the terminal opening of the cup-shaped housing portion is circular, and the cup-shaped housing portion includes a cylindrical housing shell; b. a lid component closing the circular opening of the cup-shaped housing portion has a circular circumference; c. the electrode separator assembly is in the form of a cylindrical winding having first and second terminal flat end faces, as well as a winding shell located between the end faces; d. the electrode separator assembly is axially aligned in the housing such that the wound shell abuts the interior of the cylindrical housing shell; e. the anode and anode current collector are ribbon-shaped, the anode current collector including a first longitudinal edge, a second longitudinal edge and two end portions; f. the first and parallel second edges of the anode current collector are longitudinal edges of a ribbon-shaped anode current collector; g. the main area of the anode current collector carrying the layer of negative electrode material is strip-shaped; h. a free edge strip extends along the first longitudinal edge of the anode current collector; i. the cathode and the cathode current collector are ribbon-shaped, the cathode current collector including a first longitudinal edge, a second longitudinal edge and two end portions; j. the first and second parallel edges of the cathode current collector are longitudinal edges of a ribbon-shaped cathode current collector; k. the main area of the cathode current collector carrying the layer of positive electrode material is strip-shaped; l. a free edge strip extends along the first longitudinal edge of the cathode current collector; m. one or more separators of the electrode separator assembly are ribbon-shaped; n. the anode and cathode are disposed within the electrode separator assembly such that a first longitudinal edge of the anode current collector protrudes from a first terminal end face and a first longitudinal edge of the cathode current collector protrudes from a second terminal end face of the electrode separator assembly; and o. A contact sheet metal member is on a first longitudinal edge of the anode current collector and connected thereto by welding.
[0034] In this embodiment, the electrode separator assembly preferably includes one ribbon-shaped separator or two ribbon-shaped separators, each having first and second longitudinal edges and two end portions. An electrode separator assembly always includes an electrode and a separator with an anode / separator / cathode sequence.
[0035] Particularly preferably, the energy storage element according to the invention in this embodiment always has the following features: The housing includes a lid component welded to the terminal opening in the cup-shaped housing portion and closing the terminal opening in the cup-shaped housing portion.
[0036] Preferably, a lid component with a circular circumference is positioned in the circular opening of the cup-shaped housing part such that its edge abuts the interior of the cup-shaped housing part along a circumferential contact zone, and the edge of the lid component is connected to the cup-shaped housing part by a circumferential weld seam.
[0037] Preferably, the height of the energy storage elements designed as cylindrical round cells is in the range of 50 mm to 150 mm. The diameter of the cylindrical round cells is preferably in the range of 15 mm to 60 mm. Cylindrical round cells with these form factors are particularly suitable for providing power to electric drives in motor vehicles.
[0038] If the energy storage element according to the invention is designed as a cylindrical circular cell, this preferably has a diameter of 26 mm and a height of 105 to 106 mm.
[0039] In embodiments in which the cell according to the invention is a cylindrical circular cell, the anode current collector, cathode current collector, and separator(s) preferably have the following dimensions: - Lengths ranging from 0.5m to 25m - Width in the range of 30mm~145mm In these cases, the free edge strip extending along the first longitudinal edge, which is not carrying electrode material, preferably has a width of less than or equal to 5000 μm.
[0040] Preferred Electrochemical Embodiments In another particularly preferred embodiment of the invention, the energy storage element according to the invention is characterized by one of the following features: The energy storage element is a lithium ion cell. b. The energy storage element comprises a lithium ion cell. Feature a. refers in particular to the described embodiment of the energy storage element according to the invention as a cylindrical circular cell, in which embodiment the energy storage element preferably comprises exactly one electrochemical cell. Feature b. refers in particular to the described prismatic embodiment of the energy storage element according to the invention. In this embodiment, the energy storage element may also have two or more electrochemical cells.
[0041] Essentially all electrode materials known for secondary lithium ion cells can be used as electrodes of the energy storage element.
[0042] Carbon-based particles, such as graphitic carbon or non-graphitic carbon materials capable of intercalating lithium, preferably also in particulate form, may be used as the active material in the negative electrode. Alternatively or additionally, lithium titanate (Li4Ti5O 12 ) or a derivative thereof, preferably also in particulate form, may be included in the negative electrode. In addition, the negative electrode may contain, as an active material, silicon, aluminum, tin, antimony, or a compound or alloy of these materials that can reversibly deposit and remove lithium, such as silicon oxide (especially 0.1% or more). <x<2であるSiO x ), optionally in combination with a carbon-based active material. Tin, aluminum, antimony, and silicon can form intermetallic phases with lithium. In particular in the case of silicon, its capacity to absorb lithium exceeds that of graphite or comparable materials by many times. Mixtures of silicon and carbon-based storage materials are often used. Thin anodes made of metallic lithium are also suitable.
[0043] Suitable active materials for the positive electrode include lithium metal oxide compounds and lithium metal phosphate compounds, such as LiCoO2 and LiFePO4. Additionally, the chemical formula LiNi x Mn y Co z Lithium nickel manganese cobalt oxide (NMC) of formula LiMnO2 (where x+y+z is typically 1) is particularly well suited, lithium manganese spinel (LMO) of formula LiMn2O4, or lithium manganese spinel of formula LiNi x Co y Al z Lithium nickel cobalt alumina (NCA) of formula O2 (where x+y+z is typically 1). Its derivatives, such as those of formula Li 1.11 (Ni 0.40 Mn 0.39 Co 0.16 Al 0.05 ) 0.89 O2 Lithium Nickel Manganese Cobalt Alumina (NMCA) or Li 1+x MO compounds and / or mixtures of said materials may also be used.Similarly, the active material of the cathode is preferably used in particulate form.
[0044] Furthermore, the electrodes of the energy storage element according to the invention preferably comprise an electrode binder and / or additives to improve electrical conductivity. The active material is preferably embedded in the matrix of the electrode binder, and adjacent particles in the matrix are preferably in direct contact with each other. The conductive agent serves to increase the electrical conductivity of the electrode. Common electrode binders are based on, for example, polyvinylidene fluoride (PVDF), (Li-) polyacrylate, styrene butadiene rubber or carboxymethyl cellulose, or a mixture of different binders. Common conductive agents are carbon black, fine graphite, carbon fibers, carbon nanotubes and metal powders.
[0045] The energy storage element according to the invention preferably comprises an electrolyte, in particular in the case of lithium-ion cells, at least one lithium salt, for example an electrolyte based on lithium hexafluorophosphate (LiPF6) dissolved in an organic solvent (for example in a mixture of organic carbonates or cyclic ethers, such as THF or nitriles). Other lithium salts that can be used include lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium bis(oxalato)borate (LiBOB).
[0046] The nominal capacity of the lithium-ion based energy storage element according to the invention, designed as a cylindrical round cell, is preferably up to 15000 mAh. With a 21x70 form factor, the energy storage element in one embodiment as a lithium-ion cell has a nominal capacity preferably in the range of 1500 mAh to 7000 mAh, particularly preferably in the range of 3000 to 5500 mAh. With a 18x65 form factor, the cell in one embodiment as a lithium-ion cell has a nominal capacity preferably in the range of 1000 mAh to 5000 mAh, particularly preferably in the range of 2000 to 4000 mAh.
[0047] In the European Union, manufacturers are strictly regulated in providing information on the nominal capacity of secondary batteries. For example, information on the nominal capacity of secondary nickel-cadmium batteries must be based on measurements according to the IEC / EN61951-1 and IEC / EN60622 standards, information on the nominal capacity of secondary nickel-metal hydride batteries must be based on measurements according to the IEC / EN61951-2 standard, information on the nominal capacity of secondary lithium batteries must be based on measurements according to the IEC / EN61960 standard, and information on the nominal capacity of secondary lead-acid batteries must be based on measurements according to the IEC / EN61056-1 standard. Any information on nominal capacity in the present application is also preferably based on these standards.
[0048] Preferred embodiments of the separator Preferably, the separator or separators are formed from an electrically insulating plastic film. The separator can preferably be penetrated by the electrolyte. For this purpose, the plastic film used can, for example, have micropores. The foil can, for example, consist of polyolefins or polyetherketones. Nonwovens and fabrics made of plastic materials or other electrically insulating sheet structures can also be used as separators. Preferably, separators with a thickness in the range of 5 μm to 50 μm are used.
[0049] In some particularly preferred embodiments, separators that are coated or impregnated on one or both sides with ceramic particles (e.g., Al2O3 or SiO2) are used.
[0050] The separator or separators of the assembly, particularly in prismatic embodiments of the energy storage element, may also be one or more layers of solid electrolyte.
[0051] Preferred construction of the electrode separator assembly in the form of a winding The ribbon-shaped anode, ribbon-shaped cathode and ribbon-shaped separator are preferably spirally wound in an electrode-separator assembly in the form of a winding. To manufacture the electrode-separator assembly, the ribbon-shaped electrodes are fed together with the ribbon-shaped separator to a winding device, where they are preferably spirally wound around a winding axis. In some embodiments, the electrodes and separators are wound on a cylindrical or hollow cylindrical winding core that is on the winding mandrel and remains in the winding after winding. The winding shell can be formed, for example, by a plastic film or an adhesive tape. It is also possible that the winding shell is formed by one or more separator windings.
[0052] Preferred embodiments of the current collector The current collectors of the energy storage element have the function of electrically contacting the electrochemically active components contained in the respective electrode materials over as large an area as possible. Preferably, the current collectors consist of a metal or are metallized at least on the surface.
[0053] In the case of an energy storage element according to the invention designed as a lithium-ion cell, suitable metals for the anode current collector are, for example, copper or nickel or other conductive materials, in particular copper and nickel alloys or metals coated with nickel. In particular, materials of type ENCW-004A or ENCW-008A with a copper content of at least 99.9% can be used as copper alloys. Nickel alloys of the types NiFe, NiCu, CuNi, NiCr and NiCrFe are particularly suitable. Nickel alloys of the types NiFe, NiCu, CuNi, NiCr and NiCrFe are particularly suitable. Stainless steels, for example types 1.4303 or 1.4404 or type SUS304, are also possible in principle.
[0054] In the case of an energy storage element according to the invention designed as a lithium-ion cell, aluminum or other electrically conductive materials, including aluminum alloys, are particularly suitable as metals for the cathode current collector.
[0055] Suitable aluminum alloys for the cathode current collector include Al alloys of types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series) and GM55. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg and AlMg. The aluminum content of the alloy is preferably greater than 99.5%.
[0056] Preferably, the anode current collector and / or the cathode current collector are each a metal foil with a thickness in the range of 4 μm to 30 μm, and in the case of the described configuration of the energy storage element as a cylindrical circular cell, a ribbon-shaped metal foil with a thickness in the range of 4 μm to 30 μm.
[0057] In addition to foils, however, other ribbon-shaped substrates such as metal or metallized nonwoven fabrics or open-pore metal foams or expanded metals can be used as current collectors.
[0058] The current collector preferably has each electrode material carried on either side.
[0059] In the case of the described configuration of the energy storage element as a cylindrical circular cell, it is preferred that the longitudinal edges of the separator form the end faces of the wound electrode separator assembly.
[0060] In the case of the described rectangular configuration of energy storage elements, the edges of the separators preferably form the end faces of the stack from which the edges of the current collectors project.
[0061] It is further preferred that the edges or longitudinal edges of the anode and / or cathode current collectors which protrude beyond the end faces of the windings or sides of the stack do not protrude more than 5000 μm, preferably not more than 3500 μm.
[0062] Particularly preferably, the edge or longitudinal edge of the anode current collector protrudes from the side or end face of the stack by not more than 2500 μm, particularly preferably not more than 1500 μm, and particularly preferably, the edge or longitudinal edge of the cathode current collector protrudes from the side or end face of the stack by not more than 3500 μm, particularly preferably not more than 2500 μm.
[0063] Direct contact of the edge of the anode current collector with the contact sheet metal member lowers the internal resistance of the energy storage element, thus increasing its current carrying capacity.
[0064] Preferred embodiments of the contact sheet metal member / contact sheet metal member connections to the anode current collector and negative terminal pole The contact sheet metal member is electrically connected to the negative terminal through an aperture in the lid plate to the anode current collector, in particular by welding directly to the first contact portion and / or to the anode current collector.
[0065] In a particularly preferred embodiment of the present invention, the contact sheet metal member electrically connected to the negative terminal pole is characterized by at least one of the following features a. to c.: a. The contact sheet metal members are made of nickel or copper or titanium or a nickel or copper or titanium alloy or stainless steel, for example type 1.4303 or 1.4404 or type SUS304, or nickel plated copper. b. the contact sheet metal member is made of the same material as the first contact portion; c. The contact sheet metal member is made of the same material as the anode current collector. It is preferred that the immediately preceding features a. and b., and particularly preferred also features a. to c., are realised in combination.
[0066] If the contact sheet metal part consists of the same material as the first contact part and / or the anode current collector, welding of these components is possible without problems.
[0067] In some embodiments, it may be preferred that the contact sheet metal member is not directly welded to the first contact portion, but is connected to the first contact portion via a separate current conductor. In these cases, the separate current conductor is preferably welded to the first contact portion and to the contact sheet metal member. Furthermore, in these cases, it is preferred that the separate current conductor is made of the same material and / or contact sheet metal member as the first contact portion.
[0068] Particularly preferably, the separate current conductors consist of nickel or copper or titanium or nickel or copper or titanium alloys or stainless steel, for example of type 1.4303 or 1.4404 or type SUS304. In particular, materials of type ENCW-004A or nickel alloys of types NiFe, NiCu, CuNi, NiCr and NiCrFe can be used as copper alloys. ENCW-008A with a copper content of at least 99.9% can be used. All this also applies to the contact sheet metal parts themselves.
[0069] In another particularly preferred embodiment of the invention, the contact sheet metal member electrically connected to the negative terminal pole always has at least one of the following characteristics: a. The contact sheet metal member has a preferably uniform thickness in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm. b. The contact sheet metal member has two opposing flat sides and extends substantially in only one dimension. c. The contact sheet metal member is a disk or preferably a rectangular plate. d. The contact sheet metal member is sized such that it covers at least 60% of the end face, preferably at least 70%, particularly preferably at least 80% of the first terminal end face. e. The contact sheet metal member has at least one aperture, in particular at least one hole and / or at least one slot. f. a contact sheet metal member having at least one bead appearing as an elongated depression on one flat side of the contact sheet metal member and as an elongated ridge on an opposing flat side, the contact sheet metal member resting on a first edge of the anode current collector with the flat side carrying the elongated ridge. g. A contact sheet metal member is welded to the first edge of the anode current collector in said area from the bead, specifically via one or more welded seams located at the bead.
[0070] It is particularly preferred that the immediately preceding features a., b. and d. are realised in combination. In a preferred embodiment, features a., b. and d. are realised in combination with one of features c. or e. or features f. and g. It is particularly preferred that all features a. to g. are realised in combination.
[0071] Covering the end face over as large an area as possible is important for the temperature management of the energy storage element according to the invention. The larger the coverage, the higher the possibility of contacting the first edge of the anode current collector over its entire length. The heat generated in the electrode separator assembly can therefore be better diffused through the contact sheet metal member.
[0072] In some embodiments, it has been found to be advantageous to pretreat the edge of the current collector before the contact sheet metal member is placed on top, in particular at least one recess corresponding to at least one bead or elongated ridge on the flat side of the contact sheet metal member facing towards the first terminal end face can be folded into the edge.
[0073] The edge of the current collector may also be subjected to directional shaping by pre-treatment, for example it may be curved in a defined direction.
[0074] For example, at least one aperture in the contact sheet metal member may be advantageous to allow the electrode separator assembly to be impregnated with electrolyte.
[0075] Electrical connection of the cathode current collector to the housing / second contact sheet metal member In a further particularly preferred embodiment of the invention, the energy storage element according to the invention always has at least one of the following characteristics a. to c.: a. The energy storage element includes a second contact sheet metal member mounted to a first edge of the cathode current collector and connected thereto by welding. b. A second contact sheet metal member is electrically connected to the cup-shaped housing portion. c. The second contact sheet metal member is made of aluminum or an aluminum alloy. It is particularly preferred that the immediately preceding features a. and b., and preferably also features a. to c., are realised in combination.
[0076] The second contact sheet metal member increases the current carrying capacity of the cathode side and further improves thermal management of the energy storage element.
[0077] Suitable aluminum alloys for the contact sheet metal members include Al alloys of types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series) and GM55. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg and AlMg. The aluminum content of the alloys is preferably greater than 99.5%.
[0078] The contact sheet metal member attached to the first edge of the cathode current collector is preferably formed similarly to the contact sheet metal member attached to the first edge of the anode current collector, except for its material composition, and preferably has at least one of the following characteristics a.-g.: a. The second contact sheet metal member has a preferably uniform thickness in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm. b. A second contact sheet metal member has two opposing flat sides and extends substantially in only one dimension. c. The second contact sheet metal member is a disk or preferably a rectangular plate. d. The second contact sheet metal member is sized such that it covers at least 60% of the end face, preferably at least 70%, and particularly preferably at least 80% of the second terminal end face. e. The second contact sheet metal member has at least one aperture, in particular at least one hole and / or at least one slot. f. a second contact sheet metal member having at least one bead appearing as an elongated depression on one flat side of the contact sheet metal member and as an elongated ridge on the opposite flat side, the contact sheet metal member resting on the first edge of the cathode current collector with the flat side carrying the elongated ridge. g. A second contact sheet metal member is welded to the first edge of the cathode current collector in the area from the bead, particularly via one or more welded seams located at the bead.
[0079] Also in this case, it is particularly preferred that the immediately preceding features a., b. and d. are realized in combination. In a preferred embodiment, features a., b. and d. are realized in combination with one of features c. or e. or features f. and g. It is particularly preferred that all features a. to g. are realized in combination.
[0080] The connection or welding of the first edge of the cathode current collector to the second contact sheet metal member is preferably implemented in the same way as the connection of the first edge of the anode current collector described above, i.e. particularly preferably via welding in the area from the bead.
[0081] Moreover, it may also be preferred here if the edge of the current collector has been subjected to a directional shaping by pretreatment, for example it may be curved in a defined direction.
[0082] In a preferred embodiment, the second contact sheet metal member is directly welded to the bottom or a part of the bottom of the cup-shaped housing part. In a further preferred embodiment, the second contact sheet metal member is connected to the bottom of the cup-shaped housing part via a separate current conductor. In the latter case, the separate current conductor is preferably welded to both the bottom of the cup-shaped housing part and the second contact sheet metal member. The separate current conductor preferably consists of aluminum or an aluminum alloy.
[0083] In principle, a direct connection to the bottom of the first edge of the cathode current collector is also possible. For this purpose, for example, welding can be performed by means of a laser from the outside through the bottom of the cup-shaped housing part.
[0084] Preferred embodiment of the negative terminal pole In a further particularly preferred embodiment of the invention, the energy storage element according to the invention always has at least one of the following characteristics a. to f.: The negative terminal pole includes a tubular or cup-shaped first portion that includes a first contact portion. b. The tubular or cup-shaped portion is made of nickel or copper or titanium or a nickel or copper or titanium alloy or stainless steel, for example type 1.4303 or 1.4404 or type SUS304. c. The negative terminal pole includes a terminal tubular or cup-shaped first part having a sheath of nickel or copper or a nickel or copper alloy, in particular coated with nickel or copper or a nickel or copper alloy. d. The negative terminal pole includes a second portion made of aluminum or an aluminum alloy, the second portion including the second contact portion. e. The second part is mechanically and / or welded to the first part. f. The second part comprises a pin-shaped section that is mechanically fixed in the tubular or cup-shaped part, preferably pressed onto the tubular or cup-shaped part or fixed in the tubular or cup-shaped part by a threaded connection.
[0085] It is particularly preferred that the immediately preceding features a. and b. are realised in combination. In a preferred embodiment, features a. and b. are realised in combination with features d. and e. or in combination with features d. to f. In an alternative embodiment, features c., d. and e., particularly preferably the four features c. to f., are realised in combination.
[0086] The embodiment in which the first part is tubular or cup-shaped offers a simple and elegant solution for forming the negative terminal pole. That part provides a receptacle for the pin-shaped section of the second part which can be inserted and fixed in the first part. If necessary, the mechanical fixation can also be supported by an additional welded joint.
[0087] Electrical insulation of the negative terminal pole from the lid component can be achieved, for example, by an insulating element arranged annularly around the terminal pole, which can consist of glass, a ceramic material, an electrically insulating polymer or a combination of these materials.
[0088] CID solution in the bottom region In another particularly preferred embodiment of the invention, the energy storage element according to the invention always has the combination of the following characteristics a. to e: The bottom of the cup-shaped housing part comprises an aperture, particularly preferably a circular hole, which is closed by a metal membrane. b. A metal membrane is secured to the cup-shaped housing portion by welding. c. The metal membrane includes an indentation in the area from which the membrane extends through the aperture into the interior of the housing. d. A second contact sheet metal member is electrically insulated from the bottom of the housing. e. A second contact sheet metal member is connected by welding to the portion of the metal film that extends into the interior of the housing.
[0089] This embodiment offers a reliable and at the same time space-saving way to provide the energy storage element according to the invention with a safety function. The metal membrane can be integrated without problems into the recess at the bottom. If the electrical insulation for the bottom is designed as a thin plastic foil, for example, the second contact sheet metal part can be laid flat at the bottom, separated from it only by the thin foil. If a sufficiently high overpressure occurs inside the housing, the notch is pressed outwards and the membrane tears off the contact plate. This interrupts the electrical contact to the cathode and stops the current flow. If the pressure nevertheless continues to rise, the membrane can burst.
[0090] In order to ensure that the internal pressure occurring can act on the notch in the intended manner, it may be preferable to provide an aperture, in particular a hole, in the second contact plate through which the recessed area is in fluid communication with the interior space of the housing. The thickness of the membrane can be adjusted to provide the pressure at which the fuse will operate.
[0091] Preferred embodiments of the housing part In a further particularly preferred embodiment of the invention, the energy storage element according to the invention always has at least one of the following characteristics a. to c.: a. The bottom of the cup-shaped housing portion has a thickness in the range of 200 μm to 2000 μm. b. The sidewall of the cup-shaped housing portion has a thickness in the range of 150 μm to 2000 μm. c. The lid component, in particular the lid plate of the lid component, has a thickness in the range of 200 μm to 2000 μm. It is particularly preferable that the immediately preceding features a to c are realized in combination.
[0092] Assembly of an energy storage element according to the invention The assembly according to the invention is characterized by the following features: a. the assembly comprises at least two energy storage elements according to any one of claims 1 to 7; and b. The assembly includes an aluminum or aluminum alloy conductor connected by welding to a negative terminal pole of one of the energy storage elements and to a pole of another of the energy storage elements. The aluminum conductor may be, for example, an aluminum rail.
[0093] Suitable aluminum alloys for the electrical conductors include Al alloys of types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series) and GM55. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg and AlMg. The aluminum content of the alloys is preferably greater than 99.5%.
[0094] Preferably, the electrical conductor is connected to the first contact portion of the negative terminal pole.
[0095] Method according to the invention The method according to the invention of manufacture is used to manufacture an assembly according to the invention and is characterized by the following steps: a. at least two energy storage elements according to any one of claims 1 to 7 and an electrical conductor made of aluminum or an aluminum alloy are provided; and b. An electrical conductor made of aluminum or an aluminum alloy is connected by welding to the negative terminal pole of one of the energy storage elements and to a pole of another of the energy storage elements. Particularly preferably, the welding is effected by means of a laser. [Brief description of the drawings]
[0096] Further features and advantages of the invention will become apparent from the claims and from the following description of preferred examples of embodiments of the invention in conjunction with the drawings. The individual features can be realized each separately or in combination with one another. [Figure 1] 1 shows an energy storage element according to an embodiment of the invention and its behavior in the event of overpressure as a result of a fault (cross-section). [Diagram 2] An electrode separator assembly that is part of the energy storage element shown in FIG. 1, and components thereof. [Diagram 3] Two contact sheet metal members that are components of the energy storage element shown in FIG. [Figure 4]1 shows a cross-sectional view of a negative terminal pole assembly according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0097] The energy storage element shown in Fig. 1, designed as a cylindrical circular cell with a diameter of 26 mm and a height of 105 mm, comprises a housing, which is hermetically and liquid-tightly sealed and consists of a metal housing part 101 of cup-shaped design, which includes a housing bottom 101a, a cylindrical housing shell 101b and a terminal opening of circular design, and a lid component 102 with a circular circumference. The lid component 102 is placed in the circular opening of the cup-shaped housing part 101 such that its edge abuts the interior of the cup-shaped housing part 101 along a circumferential contact zone, the edge of the lid component 102 being connected to the cup-shaped housing part 101 via a circumferential weld seam 118. As a result, the lid component 102 is welded to the terminal opening of the cup-shaped housing part 101 and closes the terminal opening of the cup-shaped housing part 101. The lid component 102 includes a metal lid plate 102a and a negative terminal 102b, which is threaded through an aperture in the lid plate 102a and is electrically insulated from the lid plate 102. To this end, the lid component 102 includes an annular insulating element 102g.
[0098] An electrode separator assembly 104 is connected in the housing. It is in the form of a cylindrical winding having a first terminal flat end surface 104a and a second terminal flat end surface 104b as well as a winding shell 104c located between the end surfaces. In the housing, the electrode separator assembly 104 is axially aligned such that the winding shell 104c abuts the inner surface of the cylindrical housing shell 101b. Only one electrical insulation layer 115, for example made of one or more plastic films, is further arranged between the winding shell 104c and the inner surface. The electrical insulation layer 115 extends over almost the entire inner surface of the housing. Both the side walls of the housing part 101 and a large area of its bottom part 101a and the inside of the cover plate 102a are protected from direct and therefore also electrical contact with the components of the electrode separator assembly 104.
[0099] The structure of the electrode separator assembly 104 is shown with reference to FIG. 2. The assembly 104 comprises a ribbon-shaped anode 105 (FIG. 2A) with a ribbon-shaped anode current collector 106 having a first longitudinal edge 106a and a second longitudinal edge parallel thereto. The anode current collector 106 is a copper or nickel foil. It comprises a strip-shaped main area carrying a layer of anode material 107 and a free edge strip 106b extending along its first longitudinal edge 106a that is free of electrode material 107. Furthermore, the assembly 104 comprises a ribbon-shaped cathode 108 (FIG. 2B) with a ribbon-shaped cathode current collector 109 having a first longitudinal edge 109a and a second longitudinal edge parallel thereto. The cathode current collector 109 is an aluminum foil. It comprises a strip-like main area carrying a layer of positive electrode material 110 and a free edge strip 109b extending along its first longitudinal edge 109a that is free of electrode material 110. Both electrodes are shown individually and in an unrolled state.
[0100] The anode 105 and cathode 108 are offset from one another within the electrode separator assembly 104 such that a first longitudinal edge 106a of the anode current collector 106 protrudes from a first terminal end face 104a and a first longitudinal edge 109a of the cathode current collector 109 protrudes from a second terminal end face 104b of the electrode separator assembly 104. The staggered arrangement can be seen in Figure 2C. Similarly, there are shown two ribbon-shaped separators 116 and 117 separating the electrodes 105 and 108 in the winding.
[0101] In Fig. 2D, the electrode separator assembly 104 is shown in a rolled form, as it may be used in an energy storage element according to Fig. 1. The electrode edges (106a, 109a) protruding from the end faces (104a, 104b) are clearly visible. The rolled shell 104c is formed by a plastic film.
[0102] Returning to Fig. 1, however, the energy storage element 100 further comprises a contact sheet metal member 111 mounted to the first longitudinal edge 106a of the anode current collector 106 and connected thereto by welding. Furthermore, the contact sheet metal member 111 is directly connected to the negative terminal 102b which is passed through an aperture in the lid plate 102a, i.e. the latter is welded to the contact sheet metal member 111. An insulating layer 115 prevents contact of the edge of the contact sheet metal member 111 with the housing part 101 and of the contact sheet metal member 111 with the lid plate 102a. A second contact sheet metal member 112 is mounted to the first protruding edge 109a of the cathode current collector 109 and connected thereto by welding.
[0103] Two contact sheet metal members 111 and 112 are shown in FIG. 3. Both are flat metal disks with a thickness ranging from 150 μm to 350 μm. Metal disk 112 is made of aluminum, while disk 111 is made of copper or nickel. Contact sheet metal members 111 and 112 have a diameter that essentially corresponds to the diameter of the wound electrode separator assembly. They therefore almost completely cover the end faces 104A and 104b. Contact sheet metal member 112 has a central hole 122 that may be useful, among other things, for impregnating the electrode separator assembly with an electrolyte. Both contact sheet metal members 111 and 112 each have three beads (111a, 111b, 111c; 112a, 112b, 112c). In the areas from these beads, contact sheet metal members 111 and 112 are welded to edges 106A and 109a.
[0104] The negative terminal 102b shown in FIG. 1 comprises a cup-shaped first part 102e, which comprises a first contact part 102c at its bottom. This contact part lies directly on the contact sheet metal part 111 and is connected thereto by welding. The welding can be performed, for example, by laser. The cup-shaped part 102e consists of nickel or copper. To facilitate welding, it preferably consists of the same material as the contact sheet metal part 111. Furthermore, the negative terminal 102b comprises a second part 102f, which is made of aluminum or an aluminum alloy. It comprises a second contact part 102d. The second part 102f comprises a pin-shaped part 102g, which is mechanically fixed in the cup-shaped part 102e. Preferably, the second part 102f is press-fitted into the cup-shaped part 102e or is fixed in the cup-shaped part 102e by a screw connection. Additional fixing by welding is possible.
[0105] The second contact portion 102d can be mechanically contacted from the outside of the housing. Due to the nature of its material, it can be easily welded to an aluminum current conductor by laser.
[0106] The second contact sheet metal member 112 is electrically connected to the cup-shaped housing portion 101 solely via the metal film 113. The second contact sheet metal member 112 is otherwise electrically insulated from the bottom portion 101a by an insulator 119, which may be in the form of a disk and may optionally also be part of the insulating layer 115.
[0107] The membrane 113 closes the aperture 101b in the bottom 101a of the housing part 101. To save space, the bottom 101a has an annular, flat recess on its outside around the aperture 101b, where the membrane 113 is fixed to the cup-shaped housing part 101 by welding. The membrane 113 then has an annular weld seam 113a. In its center, the metal membrane 113 has a notch 114 in the area where the membrane 113 extends through the aperture 101b into the housing interior. The second contact sheet metal member 112 is connected by welding to the part of the metal membrane 113 that extends into the housing interior.
[0108] Advantageously, the contact sheet metal member 112 has a number of holes 120. Through one of the holes, the aperture 101b is connected to an axial cavity 121 in the electrode separator assembly 104. If excessive pressure develops within the housing, the pressure may act on the membrane 113 through one or more of the holes. If the pressure is high enough, the notches 114 are forced outward and the membrane 113 peels off from the contact plate 112 as shown in FIG. 1A. This breaks electrical contact with the cathode 108 and stops any current flow. If the pressure nevertheless continues to rise, the membrane may burst, see FIG. 1B.
[0109] The illustrated solution is advantageous in that the fuse function is integrated into the housing bottom 101a and therefore does not take up space within the housing. Nevertheless, it is extremely reliable.
[0110] Fig. 4 shows the assembly of the negative terminal 102b shown in Fig. 1. For this purpose, the bottom of the cup-shaped first part 102e is first connected by welding to the contact sheet metal member 111. In the present case, the welding is performed by laser. Then, the pin-shaped part 102g of the second part 102f is pressed against the cup-shaped part 102e.
Claims
1. An energy storage element (100), having the following features, namely: a. It includes an airtight and liquid-tight housing and an electrode separator assembly (104) disposed therein; b. The housing includes a metallic cup-shaped housing part (101) having a housing bottom (101a) and a terminal opening; c. The housing includes a lid component (102) which is welded within the terminal opening of the cup-shaped housing part (101) and closes the terminal opening of the cup-shaped housing part (101); d. The lid component (102) includes a metallic lid plate (102a) and a negative terminal (102b) which passes through an aperture in the lid plate (102) and is electrically insulated from the lid plate (102); e. The electrode separator assembly (104) includes a first terminal end face (104a) and a second terminal end face (104b); f. The electrode separator assembly (104) includes an anode (105) provided with an anode current collector (106) having a first edge (106a) and a second edge parallel thereto; g. The anode current collector (106) includes a main region carrying a layer of negative electrode material (107) and a free edge strip (106b) extending along its first edge (106a) where the electrode material (107) is not carried; h. The electrode separator assembly (104) includes a cathode (108) provided with a cathode current collector (109) having a first edge (109a) and a second edge parallel thereto; i. The cathode current collector (109) includes a main region carrying a layer of positive electrode material (110) and a free edge strip (109b) extending along its first edge (109a) where the electrode material (110) is not carried; j. The anode (105) and the cathode (108) are disposed within the electrode separator assembly (104) such that the first edge (106a) of the anode current collector (106) protrudes from the first terminal end face (104a), and the first edge (109a) of the cathode current collector (109) protrudes from the second terminal end face (104b) of the electrode separator assembly (104). k. The energy storage element is a contact sheet metal member (111) that is mounted on the first edge (106a) of the anode current collector (106) and connected thereto by welding. l. The contact sheet metal member (111) is electrically connected to the negative terminal (102b) that passes through the aperture in the lid plate (102a). m. The negative terminal (102b) includes a first contact portion (102c) made of nickel or copper or titanium or a nickel alloy or a copper alloy or a titanium alloy or stainless steel, and a second contact portion (102d) made of aluminum or an aluminum alloy. n. The second contact portion (102d) can be mechanically contacted from the outside of the housing. An energy storage element (100) having the above characteristics. **Claim 2** The following additional characteristics, namely: a. The cup-shaped housing portion (101) is made of aluminum or an aluminum alloy. b. The lid plate (102a) is made of aluminum or an aluminum alloy. c. The lid component (102) includes a separate positive terminal pole made of aluminum or an aluminum alloy fixed to the lid plate (102a). d. The cup-shaped housing portion (101), the lid plate (102a), and the separate positive terminal pole are made of aluminum or an aluminum alloy. The energy storage element according to claim 1, having at least one of the above characteristics. **Claim 3** The following additional characteristics, namely: a. The contact sheet metal member (111) is made of nickel or copper or titanium or a nickel alloy or a copper alloy or a titanium alloy or stainless steel. b. The contact sheet metal member (111) is made of the same material as the first contact portion (102c). c. The contact sheet metal member (111) is made of the same material as the anode current collector (106). The energy storage element according to claim 1, having at least one of the above characteristics. **Claim 4** The following additional characteristics, namely: a. The contact sheet metal member (111) has a thickness in the range of 50 μm to 600 μm. b. The contact sheet metal member (111) has two opposing flat sides and extends substantially only in one dimension. c. The contact sheet metal member (111) is a disk or a rectangular plate, d. The contact sheet metal member (111) is dimensioned such that it covers at least 60% of the first terminal end face, e. The contact sheet metal member (111) has at least one aperture, f. The contact sheet metal member (111) has at least one bead that appears as a long groove on one flat side of the contact sheet metal member (111) and as a long ridge on the opposite flat side, and the contact sheet metal member (111) lies on the first edge (106a) of the anode current collector (106) on the flat side carrying the long ridge, g. The contact sheet metal member (111) is welded to the first edge (106a) of the anode current collector (106) in the region from the bead, The energy storage element according to claim 1, comprising at least one of the said features.
5. The following additional features, namely, a. The energy storage element includes a second contact sheet metal member (112) that is mounted on the first edge (109a) of the cathode current collector (109) and connected thereto by welding, b. The second contact sheet metal member (112) is electrically connected to the cup-shaped housing part (101), c. The second contact sheet metal member (112) is made of aluminum or an aluminum alloy, The energy storage element according to claim 1, comprising at least one of the said features.
6. The following additional features, namely, a. The negative terminal (102b) includes a tubular or cup-shaped first member (102e) including the first contact portion (102c), b. The tubular or cup-shaped part (102e) is made of nickel or copper or titanium or a nickel alloy or a copper alloy or a titanium alloy or stainless steel, c. The negative terminal (102b) includes a terminal tubular or cup-shaped first part having a sheath coated with nickel or copper or a nickel alloy or a copper alloy, d. The negative terminal (102b) includes a second aluminum or aluminum alloy member (102f) including the second contact portion (102d), e. The second part (102f) is fixed to the first part (102e) mechanically and / or by welding, f. The second part (102f) is a pin-shaped part (102g) that includes a pin-shaped part (102g) mechanically fixed in the tubular or cup-shaped part (102e). The energy storage element according to claim 1, comprising at least one of the features described above.
7. The following additional features, namely: a. The bottom (101a) of the cup-shaped housing part (101) includes an aperture (101b) closed by a metal film (113). b. The metal film (113) is fixed to the cup-shaped housing part (101) by welding. c. The metal film (113) includes a notch (114) in a region where the film (113) extends into the interior of the housing through the aperture (101b). d. The second contact sheet metal member (112) is electrically insulated from the bottom (101a) of the housing. e. The second contact sheet metal member (112) is connected by welding to a portion of the metal film (113) that extends into the interior of the housing. The energy storage element according to claim 5, comprising the features described above.
8. An assembly of energy storage elements, comprising: a. The assembly includes at least two energy storage elements (100) according to any one of claims 1 to 7; and b. The assembly includes a conductor made of aluminum or an aluminum alloy that is connected by welding to a negative terminal (102b) of one of the energy storage elements and to a terminal (102b) of another of the energy storage elements. The assembly of energy storage elements, comprising the features described above.
9. A method for manufacturing an assembly of energy storage elements (100), comprising: a. Providing at least two energy storage elements (100) according to any one of claims 1 to 7 and a conductor made of aluminum or an aluminum alloy; and b. Connecting the conductor made of aluminum or the aluminum alloy by welding to a negative terminal pole (102b) of one of the energy storage elements and to a pole (102b) of another of the energy storage elements. The method comprising the steps described above.