Lithium-ion batteries with high specific energy density

Abstract

The present technology relates to a lithium-ion battery (100) including a ribbon-shaped electrode-separator assembly (104) having an anode (120) / separator (118) / cathode (130) arrangement, where the anode (120) and cathode (130) each include a current collector (110, 115) having first and second longitudinal edges (110e, 115e), the current collectors each including a main region (122, 126) provided with a layer of respective electrode material (123, 125) and a free edge strip (121, 117) extending along the first longitudinal edge (110e, 115e) and not provided with electrode material. The assembly (104) is in the form of a winding having two terminal end faces and is enclosed by a housing. The anode (120) and cathode (130) are offset within the assembly (104) so ​​that a first longitudinal edge (110e) of the anode current collector projects from one of the terminal end faces, and a first longitudinal edge (115e) of the cathode current collector projects from the other of the terminal end faces. The battery (100) has metallic contact elements (101a, 102, 155) with which one of the first longitudinal edges (110e, 115e) is in direct contact and which are connected by welding. It is proposed that the separator (118) contains at least one inorganic material that improves its resistance to thermal stress.

Description

[Technical Field]

[0001] The invention described below relates to a lithium-ion battery that includes an electrode-separator assembly. [Background technology]

[0002] Electrochemical batteries can convert stored chemical energy into electrical energy through oxidation-reduction reactions. Electrochemical batteries generally contain a positive electrode 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 drawn by an external consumer. The electrochemical battery can serve as an energy source for the consumer. Simultaneously, an ionic current corresponding to the electrode reactions is generated within the battery. This ionic current crosses the separator and is carried by an ion-conducting electrolyte.

[0003] If the discharge is reversible, i.e., the conversion of chemical energy into electrical energy that occurs during discharge can be reversed, thus allowing the battery to be recharged, the battery is called a secondary battery. It is customary in secondary batteries to designate the negative electrode as the anode and the positive electrode as the cathode, which relates to the discharge function of the electrochemical cell.

[0004] Widely used secondary lithium-ion batteries are based on the use of lithium, which can be transported back and forth between the battery's electrodes in the form of ions. Lithium-ion batteries are characterized by a relatively high energy density. The negative and positive electrodes of lithium-ion batteries are generally formed by so-called composite electrodes, which contain electrochemically active and electrochemically inactive components.

[0005] In principle, any material capable of absorbing and releasing lithium ions can be used as an electrochemically active component (active material) for secondary lithium-ion batteries. Carbon-based particles, such as graphitic carbon, are often used for the negative electrode. Other non-graphitic carbon materials suitable for lithium intercalation can also be used. Additionally, metallic and semi-metallic materials capable of alloying with lithium can be used. For example, the elements tin, aluminum, antimony, and silicon can form intermetallic phases with lithium. For example, lithium cobalt oxide (LiCoO), lithium manganese oxide (LiMnO), lithium iron phosphate (LiFePO), or their derivatives can be used as active materials for the positive electrode. The electrochemically active material is generally contained in the electrode in particulate form.

[0006] As an electrochemically inactive component, a composite electrode generally includes a flat and / or strip-shaped current collector, such as a metal foil, coated with an active material. For example, the current collector for the negative electrode (anode current collector) may be made of copper or nickel, and the current collector for the positive electrode (cathode current collector) may be made of aluminum. Furthermore, the electrode may include an electrode binder (e.g., polyvinylidene fluoride (PVDF) or other polymers, such as carboxymethyl cellulose). This ensures the mechanical stability of the electrode and, in many cases, adhesion of the active material to the current collector. Furthermore, the electrode may include conductivity-improving additives and other additives.

[0007] As an electrolyte, lithium-ion batteries generally contain a lithium salt solution, such as lithium hexafluorophosphate (LiPF6), in an organic solvent (e.g., carbonate ethers and esters).

[0008] During the manufacture of lithium-ion batteries, composite electrodes are combined with one or more separators to form an assembly. In this process, the electrodes and separators are typically bonded together under pressure, optionally by lamination or bonding. Basic battery functionality can then be established by impregnating the assembly with an electrolyte.

[0009] In many embodiments, the assemblies are formed flat, allowing multiple assemblies to be stacked flat on top of each other, however, in many cases the assemblies are fabricated as or processed into windings.

[0010] Generally, the assembly includes a positive electrode / separator / negative electrode arrangement, whether wound or unwound. Often, the assembly is fabricated as a so-called bicell, the expected arrangement being negative electrode / separator / positive electrode / separator / negative electrode or positive electrode / separator / negative electrode / separator / positive electrode.

[0011] For applications in the automotive sector, electric bicycles or similarly other applications with high energy requirements such as tools, there is a need for lithium-ion batteries with the highest possible energy density that can simultaneously supply high currents during charging and discharging.

[0012] Batteries for the aforementioned applications are often designed as cylindrical round cells, for example with a form factor of 21 x 70 (diameter x height, in mm). This type of battery always includes an assembly in the form of a winding. Modern lithium-ion batteries of this form factor are already able to achieve energy densities of up to 270 Wh / kg. However, this energy density is considered only an intermediate step. The market is already demanding batteries with even higher energy densities.

[0013] However, in the development of improved lithium-ion batteries, there are other factors to consider besides energy density. The internal resistance of the battery, which must be kept as low as possible to reduce power loss during charging and discharging, and the thermal connection of the electrodes, which may be important for regulating the battery's temperature, are also crucial parameters. These parameters are also very important for cylindrical round batteries that contain composite assemblies in the form of windings. During rapid charging of the battery, heat accumulation in the battery due to power loss can lead to large thermomechanical stresses and subsequent deformation and damage to the battery structure. The risk is amplified when the electrical connection of the current collectors is made via separate conductor tabs welded to the current collectors that protrude axially from the wound assembly, because localized heating can occur at these conductor tabs under high loads during charging or discharging.

[0014] WO 2017 / 215900 A1 describes an electrode-separator assembly and a battery in which its electrodes are ribbon-shaped and in the form of a winding. Each electrode has a current collector provided with an electrode material. Electrodes of opposite polarity are offset from one another within the electrode-separator assembly, so that the longitudinal edge of the positive electrode current collector protrudes from the winding on one side, and the longitudinal edge of the negative electrode current collector protrudes from the winding on the other side. For electrical contact of the current collectors, the battery has at least one contact plate mounted on one of the longitudinal edges so as to form a linear contact zone. The contact plate is connected to the longitudinal edge by welding along the linear contact zone. This allows electrical contact to be made to the current collector, and thus to the associated electrode, over its entire length. This significantly reduces internal resistance within the described battery, allowing for very good absorption of large currents.

[0015] However, a problem with the battery described in WO 2017 / 215900 A1 is that it is very difficult to weld the longitudinal edges and contact plates together. The current collectors of the electrodes have a very thin thickness relative to the contact plates. Therefore, the edge areas of the current collectors are mechanically very sensitive and can be unintentionally crushed or melted during the welding process. Furthermore, when the contact plates are welded, the separators of the electrode-separator assembly may melt. In extreme cases, this can lead to a short circuit. Summary of the Invention [Problem to be solved by the invention]

[0016] The object of the present invention is to provide a lithium-ion battery which is characterized by an improved energy density and a current distribution which is as uniform as possible over the entire area and length of its electrodes, compared to the prior art, and which at the same time has excellent properties with regard to its internal resistance and its active heat dissipation capacity. Furthermore, the battery must also be characterized by improved manufacturability and safety. [Means for solving the problem]

[0017] This object is achieved by the lithium-ion battery described below, in particular by preferred embodiments of the lithium-ion battery described below having the features of claim 1. Preferred embodiments of this preferred embodiment will also be apparent from the dependent claims.

[0018] A lithium-ion battery according to the invention is always characterized by the following features a. to j.: a. The battery includes an electrode-separator assembly having an anode / separator / cathode arrangement, preferably a ribbon-shaped electrode-separator assembly having an anode / separator / cathode arrangement. b. The anode includes a negative electrode material and an anode current collector having first and second longitudinal edges and two end portions. c. The anode current collector is a main area provided with a layer of negative electrode material, preferably a strip-shaped main area provided with a layer of negative electrode material; a free edge strip extending along a first longitudinal edge of the anode current collector, the free edge strip being free of electrode material; It has. d. The cathode includes a positive electrode material and a cathode current collector having first and second longitudinal edges and two end portions. e. Cathode current collector a main area provided with a layer of positive electrode material, preferably a strip-shaped main area provided with a layer of positive electrode material; a free edge strip, free of electrode material, extending along a first longitudinal edge of the cathode current collector; It has. f. The electrode-separator assembly is in the form of a winding having two terminal end faces. g. The electrode-separator assembly is enclosed within a housing. h. The anode and cathode are offset within the electrode-separator assembly so that a first longitudinal edge of the anode current collector protrudes from one of the terminal end faces and a first longitudinal edge of the cathode current collector protrudes from the other of the terminal end faces. i. The battery has metallic contact elements, in particular metallic contact plates, arranged parallel to the end faces, preferably in direct longitudinal contact with one of the first longitudinal edges. j. The contact elements, in particular metallic contact plates, are connected to this longitudinal edge by welding.

[0019] Particularly preferably, the battery comprises two contact elements, in particular two metallic contact plates, one of which is in direct contact with a first longitudinal edge of the anode current collector and the other of which is in direct contact with a first longitudinal edge of the cathode current collector, the contact element and the longitudinal edge in contact with it being respectively connected to one another by welding.

[0020] The current collector has the function of electrically contacting the electrochemically active components contained in the electrode material over as large an area as possible. Preferably, the current collector is made of metal or is metallized at least on the surface. Suitable metals for the anode current collector include copper or nickel or other conductive materials, particularly copper alloys and nickel alloys or nickel-coated metals. Stainless steel is also usually possible. Suitable metals for the cathode current collector include aluminum or other conductive materials, particularly aluminum alloys.

[0021] Preferably, the anode current collector and / or the cathode current collector are each a metal foil having a thickness in the range of 4 μm to 30 μm, particularly a ribbon-shaped metal foil having a thickness in the range of 4 μm to 30 μm.

[0022] However, in addition to foils, other strip-shaped substrates can be used as current collectors, such as metallic or metallized nonwoven fabrics, or open-cell foams, or expanded metals.

[0023] The current collector is preferably provided with a respective electrode material on both sides.

[0024] In the free edge strips, the metal of the respective current collector does not contain the respective electrode material. Preferably, the metal of the respective current collector is not covered there, so that the metal is available for electrical contact, for example by welding. Particularly preferably, the lithium-ion battery according to the invention is a secondary lithium-ion battery.

[0025] Essentially, all known electrode materials for secondary lithium-ion batteries can be used for the anode and cathode of the battery.

[0026] Carbon-based particles, preferably also in particulate form, capable of intercalating lithium, such as graphitic or non-graphitic carbon materials, can be used as the active material in the negative electrode. Alternatively or additionally, lithium titanate (Li4Ti5O 12) or a derivative thereof may preferably be included in the negative electrode in particulate form as well.

[0027] In particular, the battery according to the invention has the following characteristics: k. The separator includes at least one inorganic material that improves its resistance to thermal stress.

[0028] This material protects the separator from shrinkage as a result of localized heating, which can occur especially when the contact elements, especially the contact plates, are welded together, thus significantly reducing the risk of short circuits.

[0029] In a preferred further development, the battery according to the invention has at least one of the following characteristics a. to c.: a. The electrode-separator assembly includes a first separator and a second separator. b. The first separator and the second separator are identical. c. The electrode-separator assembly has an anode / first separator / cathode / second separator arrangement or a first separator / anode / second separator / cathode arrangement.

[0030] It is particularly preferred that the immediately preceding features a. and c. and optionally the immediately preceding features a. to c. are realized in combination with one another.

[0031] Preferably, both the first and second separators are improved against thermal stress with at least one inorganic material.

[0032] In a further possible preferred development, the battery according to the invention has at least one of the following characteristics a. or b.: a. The first and / or second separator is an electrically insulating sheet, such as a foil or a fabric or a nonwoven fabric, made of at least one plastic, in particular having a thickness in the range of 5 μm to 50 μm, preferably in the range of 10 μm to 30 μm. b. The edges of the first and / or second separator, particularly the longitudinal edges of the first and / or second separator, form the end faces of the electrode-separator assembly.

[0033] It is particularly preferred that the immediately preceding features a. and b. are realized in combination with each other.

[0034] The above information regarding preferred thicknesses of the separator relates to separators comprising inorganic materials.

[0035] It is particularly preferred that the longitudinal edges of the anode current collector and / or cathode current collector that protrude beyond the terminal end face of the winding are no more than 5000 μm, preferably no more than 3500 μm, from the end or side face.

[0036] Particularly preferably, the longitudinal edges of the anode current collector protrude by no more than 2500 μm, particularly preferably no more than 1500 μm, from the end face of the winding.Particularly preferably, the longitudinal edges of the cathode current collector protrude by no more than 3500 μm, particularly preferably no more than 2500 μm, from the end face of the winding.

[0037] The projections of the anode and / or cathode current collectors refer to the free projections before their side or end faces come into contact with the contact elements, especially the contact plates. When welding onto the contact elements, especially the contact plates, deformation of the edges of the current collectors may occur.

[0038] The smaller the selected free protrusion, the larger the preferably strip-shaped main area of ​​the current collector that is covered with electrode material can be made, which can positively contribute to the energy density of the battery according to the invention.

[0039] When the electrode-separator assembly is in the form of a winding having two terminal end faces, the separator is preferably ribbon-shaped, particularly having first and second longitudinal edges and two end faces.

[0040] In a preferred further development, the battery of the invention has the following characteristics a.: a. At least one inorganic material is contained in the separator, particularly the first separator and / or the second separator, as a particulate filler material.

[0041] Thus, the separator may preferably be an electrically insulating plastic film with particulate filler material embedded therein. The plastic film preferably has micropores, for example, so that it can be permeated by the electrolyte. The foil may be made of, for example, polyolefin or polyetherketone. It is not excluded that nonwoven fabrics and textiles made from such plastic materials may also be used.

[0042] The proportion of particulate filler material in the separator is preferably at least 40% by weight, particularly preferably at least 60% by weight.

[0043] In a further preferred development, the battery according to the invention has the following characteristics a. a. At least one inorganic material is present as a coating on the surface of the separator, particularly the first separator and / or the second separator.

[0044] Thus, the separator may preferably be a plastic film, or a nonwoven, or fabric or other electrically insulating sheet material coated with a particulate filler material.

[0045] In this case, a separator having a base thickness in the range of 5 μm to 20 μm, preferably in the range of 7 μm to 12 μm, is preferably used. The total thickness of the separator results from the base thickness and the coating thickness.

[0046] In some embodiments, only one side of the sheet-like structure, particularly a plastic film, is coated with the inorganic material. In further embodiments, the sheet-like structure, particularly a plastic film, is preferably coated on both sides with the inorganic material.

[0047] The coating thickness is preferably in the range of 0.5 μm to 5 μm. Therefore, in the case of double-sided coating, the total thickness of the separator is preferably in the range of 6 μm to 30 μm, particularly preferably in the range of 8 μm to 22 μm. In the case of single-sided coating, the thickness is preferably in the range of 5.5 μm to 20.5 μm, particularly preferably in the range of 7.5 μm to 17 μm.

[0048] If desired, the separator used may preferably also contain an inorganic material as a filler and the same or a different inorganic material as a coating.

[0049] In further possible preferred developments, the battery according to the invention has at least one of the following characteristics a. to e.: a. The at least one inorganic material is or includes an electrically insulating material. b. The at least one inorganic material is or includes at least one material selected from the group consisting of ceramic materials, glass-ceramic materials, and glasses. c. At least one inorganic material is or includes a lithium ion conducting ceramic material, such as Li5AlO4*Li4SiO4 or LiAlSi2O6. d. At least one inorganic material is or includes an oxide material, particularly a metal oxide. e. The ceramic or oxide material is aluminum oxide (Al2O3), titanium oxide (TiO2), titanium nitride (TiN), titanium aluminum nitride (TiAlN), silicon oxide, in particular silicon dioxide (SiO2), or titanium carbonitride (TiCN).

[0050] It is particularly preferred that the immediately preceding features a. to c., or the immediately preceding features a., b. and d., or the immediately preceding features a., b. and e. are realized in combination with one another.

[0051] Among the above-mentioned materials, aluminum oxide (Al2O3), titanium oxide (TiO2) and silicon dioxide (SiO2) are particularly preferred as coating materials.

[0052] In further possible preferred developments, the battery according to the invention has at least one of the following characteristics a. to c.: a. The first separator and / or the second separator include at least one inorganic material only in regions. b. The first separator and / or the second separator) have an edge strip along the first longitudinal edge and / or the second longitudinal edge, the edge strip including at least one inorganic material as a coating and / or particulate filler material. c. The first separator and / or the second separator preferably have ribbon-shaped main regions, and the main regions are free of at least one inorganic material.

[0053] It is particularly preferable that the immediately preceding features a to c be realized in combination with one another.

[0054] It is by no means important that the separator contain a uniform distribution of inorganic material or that the separator be uniformly coated with material everywhere. In fact, it may even be preferable that the separator not contain inorganic material in certain regions, such as the aforementioned main regions. In these regions, an increase in the thermal resistance of the separator is not as necessary as at the separator's edges. In addition, especially in these regions, inorganic material may contribute to an unnecessary increase in the internal resistance of the battery according to the present invention.

[0055] Current collector edge protection In some embodiments, the metal of each current collector in the free edge strip may be coated with a support material that is more heat resistant than the material coating the current collector and that is different from the electrode material disposed on each current collector.

[0056] In this context, more heat resistant is intended to mean that the support material remains solid at temperatures at which the metal of the current collector melts. Thus, either the support material has a higher melting point than the metal, or the support material only sublimes or decomposes at temperatures at which the metal is already molten.

[0057] Preferably, both the anode current collector and the cathode current collector each have a free edge strip along their first longitudinal edge that is not provided with the respective electrode material. In a further development, it is preferred that both at least one free edge strip of the anode current collector and at least one free edge strip of the cathode current collector are coated with a support material. Particularly preferably, the same support material is used for each region.

[0058] In principle, the support material that can be used in connection with the present invention can be a metal or metal alloy, provided that it has a higher melting point than the metal that constitutes the surface to be coated with the support material. However, in many embodiments, the lithium-ion battery according to the present invention preferably has at least one of the following additional features a. to d.: a. The support material is a non-metallic material. b. The support material is an electrically insulating material. c. The non-metallic material is a ceramic material, a glass-ceramic material, or a glass. d. The ceramic material is aluminum oxide (Al2O3), titanium oxide (TiO2), titanium nitride (TiN), titanium aluminum nitride (TiAlN), silicon oxide, in particular silicon dioxide (SiO2), or titanium carbonitride (TiCN).

[0059] According to the invention, the support material is particularly preferably characterized according to the immediately preceding characteristic b., and especially preferably characterized according to the immediately preceding characteristic d.

[0060] The term non-metallic materials includes in particular plastic, glass and ceramic materials.

[0061] The term "electrically insulating material" is understood broadly in this context. In principle, electrically insulating materials include any electrically insulating material, in particular the aforementioned plastics.

[0062] The term ceramic material is understood broadly in this context and in particular includes carbides, nitrides, oxides, silicides or mixtures and derivatives of these compounds.

[0063] The term "glass-ceramic material" especially refers to a material comprising crystalline particles embedded in an amorphous glass phase.

[0064] The term "glass" basically means any inorganic glass that meets the thermal stability criteria defined above and is chemically stable with respect to any electrolyte that may be present in the battery.

[0065] Particularly preferably, the anode current collector is made of copper or a copper alloy, while the cathode current collector is made of aluminum or an aluminum alloy, and the support material is aluminum oxide or titanium oxide.

[0066] It may further be preferred that the free edge strips of the anode and / or cathode current collectors are coated with a strip of support material.

[0067] The strip-shaped main areas, in particular the strip-shaped main areas of the anode current collector and the cathode current collector, preferably extend parallel to the respective longitudinal edges of the current collectors, preferably over at least 90%, particularly preferably over at least 95%, of the area of ​​the anode current collector and the cathode current collector.

[0068] In some preferred embodiments, the support material is preferably applied immediately adjacent to the strip-shaped main area, without completely covering the free area in the process. For example, the support material is applied in the form of strips or lines along the longitudinal edges of the anode and / or cathode current collectors, so that the support material covers only a portion of each edge strip. A narrow portion of the free edge strip may remain uncovered directly along this longitudinal edge.

[0069] Accordingly, the battery according to the invention may preferably be characterized by at least one of the following features a. to c.: a. The free edge strip of the anode current collector and / or the free edge strip of the cathode current collector includes a first sub-region and a second sub-region, the first sub-region being coated with a support material while the second sub-region is not coated. b. The first sub-region and the second sub-region each have the shape of a line or strip and extend parallel to each other. c. The first sub-region is located between the strip-shaped main region of the anode current collector or cathode current collector and the second sub-region.

[0070] It is particularly preferable that the immediately preceding features a to c be realized in combination with one another.

[0071] In an alternative embodiment, the battery according to the invention may preferably be characterized by the following feature a. a. The free edge strip of the anode current collector and / or the free edge strip of the cathode current collector is coated with a support material up to a first longitudinal edge.

[0072] Particularly preferably, the battery according to the invention is characterized by a combination of the following features a. and b.: a. The separator comprises at least one inorganic material only in sub-regions. b. The separator comprises at least one inorganic material in a region covering the interface between the support material and each adjacent electrode material in the electrode-separator assembly.

[0073] Preferred embodiments of electrode materials and electrolytes. In some particularly preferred embodiments, the batteries of the present invention have the following characteristics: a. The negative electrode material contains at least one material selected from the group consisting of silicon, aluminum, tin, antimony, or compounds or alloys of these materials, which is capable of reversibly intercalating and deintercalating lithium as an active material, in an amount of 20% to 90% by weight.

[0074] The weights given here refer to the dry mass of the negative electrode material, i.e., without electrolyte and without taking into account the weight of the anode current collector.

[0075] Tin, aluminum, antimony and silicon are capable of forming intermetallic phases with lithium, and their capacity to absorb lithium, especially in the case of silicon, exceeds that of graphite or comparable materials by many times.

[0076] Among the above-mentioned active materials, which are preferably also used in particulate form, silicon is particularly preferred. Particularly preferred according to the invention are batteries whose negative electrode contains silicon as active material in a proportion of 20% to 90% by weight.

[0077] Some compounds of silicon, aluminum, tin, and / or antimony can also reversibly incorporate and release lithium. For example, in some preferred embodiments, silicon may be present in the negative electrode in the form of an oxide. In these embodiments, it may be preferred that the negative electrode contain silicon oxide in an amount ranging from 20% to 90% by weight.

[0078] The design of the battery according to the invention allows for a significant advantage: As mentioned at the outset, electrodes whose current collectors are electrically connected via the separate conductor tabs mentioned at the outset are subjected to greater thermomechanical stresses during charging and discharging in the immediate vicinity of the conductor tabs than further away from them. This difference is particularly evident in the case of negative electrodes that contain silicon, aluminum, tin and / or antimony as active materials.

[0079] The electrical connection of the current collectors via the contact elements, particularly the contact plates, not only allows for relatively uniform and efficient heat dissipation in the battery according to the present invention, but also distributes the thermomechanical loads occurring during charging and discharging evenly across the windings. Surprisingly, this makes it possible to control a very high proportion of silicon, tin, and / or antimony in the negative electrode. If the proportion is greater than 50%, damage as a result of the thermomechanical loads during charging and discharging occurs relatively rarely or not at all. By increasing the proportion of silicon, for example in the anode, the energy density of the battery can be significantly increased.

[0080] Those skilled in the art will understand that tin, aluminum, silicon, and antimony do not necessarily have to be metallic in their purest form. For example, silicon particles may also contain traces or proportions of other elements, in particular other metals (except for lithium, which is contained in any case as a function of the charge state), for example in proportions of up to 40% by weight, in particular in proportions of up to 10% by weight. Therefore, alloys of tin, aluminum, silicon, and antimony may also be used.

[0081] In a particularly preferred embodiment, the battery according to the invention has at least one of the following characteristics a. and b.: a. The negative electrode material further comprises, as the negative electrode active material, carbon-based particles capable of reversibly taking up and releasing lithium, such as graphitic carbon, and in particular a mixture of silicon and these carbon-based particles. b. The carbon-based particles capable of intercalating lithium are present in the electrode material in a proportion of 5% to 75% by weight, particularly 15% to 45% by weight.

[0082] In a further particularly preferred embodiment, the battery according to the invention has at least one of the following characteristics a. to c.: a. The negative electrode material includes an electrode binder and / or a conductive agent. b. The electrode binder is present in the negative electrode material in a proportion of 1% to 15% by weight, particularly 1% to 5% by weight. c. The conductive agent is present in the negative electrode material in a proportion of 0.1% by weight to 15% by weight, particularly in a proportion of 1% by weight to 5% by weight.

[0083] It is particularly preferable that the immediately preceding features a to c be realized in combination with one another.

[0084] The active material is preferably embedded in a matrix of the electrode binder, with adjacent particles in the matrix preferably in direct contact with each other.

[0085] The conductive agent functions to increase the electrical conductivity of the electrode. The common electrode binder is, for example, based on polyvinylidene fluoride (PVDF), polyacrylate, or carboxymethyl cellulose. The common conductive agent is carbon black or metal powder.

[0086] In the context of the present invention, it is particularly preferred that the positive electrode material comprises a PVDF binder and the negative electrode material comprises a polyacrylate binder, in particular lithium polyacrylic acid.

[0087] Suitable active materials for the positive electrode include lithium metal oxide compounds and lithium metal phosphate compounds, such as LiCoO2 and LiFePO4. Additionally, lithium metal phosphate compounds of the formula LiNi x Mn y Co zLithium nickel manganese cobalt oxide (NMC) with the formula LiMnO2 (x+y+z is typically 1), lithium manganese spinel (LMO) with the formula LiMn2O4 or LiNi x Co y Al z Lithium nickel cobalt alumina (NCA) with O2 (x+y+z is typically 1) is particularly well suited. Its derivatives, such as those with the formula Li 1.11 (Ni 0.40 Mn 0.39 Co 0.16 Al 0.05 ) 0.89 Lithium Nickel Manganese Cobalt Alumina (NMCA) or Li with O 1+x MO compounds and / or mixtures of these materials can also be used.

[0088] The high silicon content in the anode of the cell according to the invention requires a correspondingly large cathode capacity to achieve good cell balance, therefore NMC, NCA or NMCA are particularly preferred.

[0089] In a particularly preferred embodiment, the battery according to the invention has at least one of the following characteristics a. to e.: a. The positive electrode material comprises as an active material at least one metal oxide compound capable of reversibly intercalating and deintercalating lithium, preferably one of the compounds listed above, in particular NMC, NCA or NMCA. b. The at least one oxide compound is present in the electrode material in a proportion of 50% to 99% by weight, in particular in a proportion of 80% to 99% by weight. c. The positive electrode material also preferably includes an electrode binder and / or a conductive agent. d. The electrode binder is present in the positive electrode material in a proportion of 0.5% to 15% by weight, particularly preferably 1% to 10% by weight, and especially preferably 1% to 2% by weight. e. The conductive agent is contained in the positive electrode material at a ratio of 0.1% by weight to 15% by weight.

[0090] It is particularly preferred that the immediately preceding features a. to e. are realized in combination with one another.

[0091] For both the positive and negative electrodes, the percentages of each component contained in the electrode material preferably add up to 100% by weight.

[0092] High-capacity cathodes can reversibly store lithium in the range of 200–250 mAh / g, while the theoretical capacity of silicon is approximately 3500 mAh / g. This results in a relatively thick cathode with a high surface charge and a very thin anode with a low surface charge. Because materials such as silicon react strongly to small voltage changes due to their very high capacitance, the anode current collector must be coated as uniformly as possible. Even small differences in current collector loading and / or electrode material densification can lead to strong local deviations in electrode balance and / or stability.

[0093] For this reason, in a preferred embodiment, the battery of the present invention has the following characteristics: a.At least 10 cm 2 The weight per unit area of ​​the negative electrode deviates from the average value by up to 2%.

[0094] The mean value is the sum of at least 10 measurements divided by the number of measurements taken.

[0095] Furthermore, the battery preferably comprises an electrolyte based on at least one lithium salt, such as lithium hexafluorophosphate (LiPF), dissolved in an organic solvent (e.g., a mixture of organic carbonates or cyclic ethers, such as THF or nitriles). Other lithium salts that may be used include lithium tetrafluoroborate (LiBF), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium bis(oxalato)borate (LiBOB).

[0096] In a particularly preferred embodiment, the battery according to the present invention has at least one of the following characteristics a. to d.: a. The battery contains an electrolyte comprising a mixture of tetrahydrofuran (THF) and 2-methyltetrahydrofuran (mTHF). b. The volume ratio of THF to mTHF in the mixture is in the range of 2:1 to 1:2, and particularly preferably 1:1. c. The battery contains an electrolyte containing LiPF6 as a conductive salt. d. The electrolyte contains a conductive salt in a proportion of 1 to 2.5M, particularly 1 to 1.5M.

[0097] Particularly preferably, the electrolyte of the battery according to the present invention is characterized by all of the above characteristics a. to d.

[0098] In an alternative particularly preferred embodiment, the battery according to the invention has at least one of the following characteristics a. to e.: a. The battery contains an electrolyte comprising a mixture of fluoroethylene carbonate (FEC) and ethyl methyl carbonate (EMC). b. The volume ratio of FEC to EMC in the mixture is in the range of 1:7 to 5:7, and particularly preferably 3:7. c. The battery contains an electrolyte containing LiPF6 as a conductive salt. d. The conductivity salt is present in the electrolyte at a concentration of 1.0 to 2.0M, particularly 1.5M. e. The electrolyte contains vinylene carbonate (VC), particularly in a proportion of 1 to 3% by weight.

[0099] Particularly preferably, the electrolyte of the battery according to the present invention is characterized by all of the above characteristics a. to e.

[0100] To improve cycling stability, the capacitance ratio of the anode and cathode of the battery of the present invention is preferably balanced so that the potential capacitance of silicon is not fully utilized.

[0101] Particularly preferably, the battery according to the invention has the following characteristic a: a. The capacitance between the anode and cathode of the battery of the present invention is balanced during operation so that only 700-1500 mAh per gram of electrode material in the negative electrode is reversibly used. By this means it is possible to significantly reduce the volume change.

[0102] It should be emphasized that all of the described embodiments in which the negative electrode material comprises at least one material from the group comprising silicon, aluminum, tin, antimony, and compounds or alloys of these materials, capable of reversibly incorporating and releasing lithium as an active material, can be realized completely independently of claim j. The present invention therefore also includes batteries having features a. to i. of claim 1, in which the anode must comprise silicon, aluminum, tin, and / or antimony as an active material in a proportion of 20% to 90% by weight, but the separator does not necessarily have to comprise at least one inorganic material that improves its resistance to thermal stress.

[0103] Preferred Embodiments of the Contact Element The concept of welding the edges of a current collector with contact plates is already known from WO 2017 / 215900 A1 or JP 2004-119330 A. The use of contact plates allows for a particularly high current-carrying capacity and low internal resistance. Therefore, full reference is made to the contents of WO 2017 / 215900 A1 and JP 2004-119330 A regarding the methods for electrically connecting contact elements, in particular contact plates, to the edges of the current collector.

[0104] In the simplest case, the contact element is a sheet metal part designed to rest flat on the end face of the wound electrode-separator assembly, which is important to ensure an effective weld.

[0105] As already mentioned above, the contact elements are preferably designed as contact plates, ie are plate-shaped.

[0106] In some preferred embodiments, the battery according to the present invention has at least one of the following characteristics a. and b.: a. Metal plates having a thickness in the range of 50 μm to 600 μm, preferably in the range of 150 to 350 μm, are used as contact elements, in particular contact plates. b. The contact elements, in particular the contact plates, are made of alloyed or unalloyed aluminum, titanium, nickel or copper, but also stainless steel (for example type 1.4303 or 1.4304) or nickel-plated steel if desired.

[0107] In some embodiments, contact elements, in particular contact plates, can be used that have at least one slot and / or at least one perforation, which have the function of compensating for deformations of the plate during the production of the welded joint.

[0108] As will be explained in more detail below, the housing in which the electrode-separator assembly resides can be cylindrical or prismatic.

[0109] If the housing is cylindrical, then a contact element, in particular a contact plate, having a disk shape, in particular a circular or at least approximately circular disk shape, is preferably used. The contact element then has a circular or at least approximately circular outer disk edge. In this context, an approximately circular disk is to be understood as a disk having the shape of a circle, in particular with at least one segmented segment, preferably 2 to 4 segmented segments.

[0110] If the housing is prismatic, contact elements, in particular contact plates, with a rectangular basic shape are preferably used.

[0111] In a simpler case, the contact element may be a metal strip or may have a number of strip-shaped segments, for example a star-shaped configuration. In a particularly preferred embodiment, the anode current collector and the contact element welded to it, in particular the contact plate welded to it, are both made of the same material, which is particularly preferably selected from the group comprising copper, nickel, titanium, nickel-plated steel and stainless steel.

[0112] In a further particularly preferred embodiment, the cathode current collector and the contact element welded thereto, in particular the contact plate welded thereto, are both made of the same material, which is particularly preferably selected from the group comprising alloyed or unalloyed aluminum, titanium and stainless steel (for example type 1.4404).

[0113] As mentioned above, the battery according to the invention has a metallic contact element, in particular a metallic contact plate, with which one of the first longitudinal edges is preferably in direct longitudinal contact, which can result in a linear contact zone.

[0114] In a possible further preferred development, the battery according to the invention has at least one of the following characteristics a. to c.: a. The first longitudinal edge of the anode current collector is preferably in direct longitudinal contact with a metallic contact element, in particular a metallic contact plate, and is connected to this contact element, in particular to this contact plate, by welding, so that there is a linear contact zone between the longitudinal edge and the metallic contact element, in particular the metallic contact plate. b. The first longitudinal edge of the cathode current collector is preferably in direct longitudinal contact with a metallic contact element, in particular a metallic contact plate, and is connected to this contact element, in particular to this contact plate, by welding, so that there is a linear contact zone between the longitudinal edge and the metallic contact element, in particular the metallic contact plate. c. The first longitudinal edge of the anode current collector and / or the first longitudinal edge of the cathode current collector comprises one or more sections, each of which is continuously connected over its entire length via a welded seam to a respective contact element, in particular a respective contact plate.

[0115] The immediately preceding features a. and b. may be realized both independently of each other and in combination. Preferably, however, features a. and b. are realized in both cases in combination with the immediately preceding feature c.

[0116] Via the contact elements, it is possible to electrically contact the current collector, and thus also the associated electrode, preferably over its entire length. This significantly reduces the internal resistance in the battery according to the invention. The described arrangement is therefore able to better absorb the generation of large currents. Since the internal resistance is minimized, heat loss at high currents is reduced. In addition, dissipation of heat energy from the electrode-separator assembly is desirable.

[0117] There are several ways in which the contact elements can be connected to the longitudinal edges.

[0118] The contact element can be connected to the longitudinal edge along the linear contact zone via at least one weld seam. The longitudinal edge can therefore comprise one or more sections, each of which is continuously connected to the contact element, in particular the contact plate, via a weld seam over its entire length. Particularly preferably, these sections have a minimum length of 5 mm, preferably 10 mm, particularly preferably 20 mm.

[0119] In a further possible embodiment, the section that is continuously connected to the contact element, in particular the contact plate, over its entire length extends over at least 25%, preferably at least 50%, particularly preferably at least 75% of the total length of the respective longitudinal edge.

[0120] In some preferred embodiments, the longitudinal edge is continuously welded along its entire length to the contact element, in particular to the contact plate.

[0121] In a further possible embodiment, the contact elements are connected to the respective longitudinal edges via a plurality of weld spots.

[0122] If the electrode-separator assembly is a spiral winding, the longitudinal edges of the anode and cathode current collectors that protrude from the terminal end faces of the winding also generally have a spiral shape, and the same applies to the linear contact zones along which the contact elements, in particular contact plates, are welded to the respective longitudinal edges.

[0123] Preferred Embodiments of the Housing In the manufacture of electrode and separator assemblies, care is generally taken to ensure that current collectors of opposite polarity do not protrude from one side, as this can increase the risk of short circuits. However, in the staggered anode and cathode arrangement described above, current collectors of opposite polarity protrude from opposite end faces of the windings, minimizing the risk of short circuits.

[0124] The protrusions of the current collectors resulting from the staggered arrangement can be utilized in accordance with the present invention, preferably by contacting the current collectors over their entire length with a suitable diverter. According to the present invention, the aforementioned contact elements function as diverters. Such electrical contact significantly reduces the internal resistance within the battery according to the present invention. The described arrangement is therefore very well able to absorb the generation of large currents. Because the internal resistance is minimized, heat loss at high currents is reduced. Additionally, dissipation of thermal energy from the wound electrode-separator assembly is desirable. Under high loads, heating does not occur locally, but rather is uniformly distributed.

[0125] In addition to the elements mentioned above, the lithium ion battery according to the present invention also conveniently includes a housing made up of two or more housing parts, which preferably encloses the electrode-separator assembly in the form of a winding in an airtight and / or liquidtight manner.

[0126] When using contact elements, it is generally necessary to electrically connect the contact elements to the housing or to electrical conductors leading out of the housing. For example, for this purpose, the contact elements can be connected to the aforementioned housing parts directly or via electrical conductors.

[0127] In a particularly preferred embodiment, the battery according to the invention is characterized in that a part of the housing serves as a contact element, in particular a contact plate, and / or that the contact element, in particular a contact plate, forms part of the housing enclosing the electrode-separator assembly.

[0128] These embodiments are particularly advantageous. On the one hand, they are optimal in terms of heat dissipation. Heat generated in the windings can be dissipated directly into the housing via the edges, especially the longitudinal edges. Secondly, the internal volume of a housing having given external dimensions can be utilized almost optimally in this way. Each separate contact element and each separate conductor connecting the contact element to the housing requires space within the housing, contributing to the weight of the battery. By eliminating such separate components, this space can be utilized for the active material. Thus, the energy density of the battery according to the invention can be further increased.

[0129] In a first particularly preferred contact variant, the battery according to the invention always has at least one, particularly preferably a combination of two, of the following characteristics a. and b.: a. The housing includes a cup-shaped first housing part having a bottom and a circumferential sidewall and an opening, and a second housing part closing the opening. b. The contact element, in particular the contact plate, is the bottom of the first housing part.

[0130] Preferably, the housing is cylindrical or prismatic in shape. Correspondingly, the cup-shaped first housing part preferably has a circular or rectangular cross section, and the second housing part and the bottom of the first housing part are preferably circular or rectangular in shape.

[0131] When the electrode-separator assembly is in the form of a winding having two terminal end faces, the housing is preferably cylindrical.

[0132] If the housing is cylindrical, it generally comprises a cylindrical housing shell and a circular top and a circular bottom, whereby in this variant the first housing part comprises the housing shell and the circular bottom, while the second housing part corresponds to the circular top. The circular top and / or the circular bottom can function as contact elements, in particular contact plates.

[0133] If the housing is prismatic, it generally comprises several rectangular side walls and a polygonal, in particular rectangular, top and a polygonal, in particular rectangular, bottom, whereby in this variant the first housing part comprises the side walls and the polygonal bottom, while the second housing part corresponds to the circular polygonal top. The top and / or the bottom can function as contact elements, in particular contact plates.

[0134] The first and second housing parts are preferably made of an electrically conductive material, in particular a metallic material, and may for example be made independently of one another of nickel-plated sheet steel or alloyed or unalloyed aluminum.

[0135] In a preferred further development of the first contact variant, the battery according to the invention has at least one of the following characteristics a. to e., in particular a combination of the following characteristics a. to e.: a. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the anode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. b. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the cathode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. c. One of the contact elements, in particular one of the contact plates, is the bottom of the first housing part. d. The other of the contact elements, in particular the other of the contact plates, is connected to the second housing part via an electrical conductor. e. The battery includes a seal that electrically isolates the first and second housing parts from each other.

[0136] In this embodiment, conventional housing parts can be used to enclose the electrode-separator assembly. No space is wasted for electrical conductors placed between the bottom and the electrode-separator assembly. Separate contact elements, especially separate contact plates, are not required on the bottom surface. To close the housing, an electrically insulating seal can be routed over the edge of the second housing part. The assembly including the second housing part and the seal can be inserted into an opening in the first housing part and mechanically fixed thereto, for example, by a crimping process.

[0137] In a particularly preferred embodiment of the first contact variant, the second housing part can serve as a contact element, in particular a contact plate. In this embodiment, the battery according to the invention always has at least one of the following features, in particular a combination of the features a. to e. immediately preceding: a. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the anode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. b. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the cathode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. c. One of the contact elements, in particular one of the contact plates, is the bottom of the first housing part. d. The other of the contact elements, in particular the other of the contact plates, is a second housing part. e. The battery includes an electrical seal that electrically isolates the first and second housing parts from each other.

[0138] In this embodiment, no electrical conductors are required on either side of the electrode-separator assembly to connect the contact elements to the housing parts. On one side, the contact elements have the additional function of the housing part, and on the other side, part of the housing acts as the contact element. The space inside the housing can be optimally used.

[0139] In a further preferred further development of the first contact variant, the battery according to the invention is characterized by at least one of the following features a. to e.: a. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the anode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. b. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the cathode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. c. One of the contact elements, in particular one of the contact plates, is the bottom of the first housing part. d. The second housing part is welded into the opening in the first housing part and includes a pole bushing, e.g., a pole stud surrounded by an electrical insulator, through which the electrical conductor is led out of the housing. e. The other of the contact elements, in particular the other of the contact plates, is electrically connected to this electrical conductor.

[0140] It is particularly preferred that the immediately preceding features a. to e. are realized in combination with one another.

[0141] In this embodiment, the housing parts are welded together and therefore electrically connected, which is why the aforementioned pole bushing is required.

[0142] In a second preferred contact variant, the battery according to the invention directly has at least one of the following characteristics a. and b., particularly preferably a combination of two characteristics: a. The housing includes a tubular first housing part having two terminal openings, a second housing part closing one of the openings, and a third housing part closing the other of the openings. b. The contact element, in particular the contact plate, is the second or third housing part.

[0143] In this contact variant, the battery housing is also preferably cylindrical or prismatic, the tubular first housing part having a circular or rectangular cross section, and the second and third housing parts are preferably circular or rectangular.

[0144] If the housing is cylindrical, the first housing part is generally a hollow cylinder, while the second and third housing parts are circular and can function as contact elements, in particular contact plates, and at the same time as a bottom and a lid that can close the first housing part at its ends.

[0145] When the housing is prismatic, the first housing part generally includes a plurality of rectangular side walls connected to one another by a common edge, while the second and third housing parts are each polygonal, particularly rectangular, and can function as contact elements, particularly contact plates.

[0146] The first and second housing parts are preferably made of an electrically conductive material, in particular a metallic material. For example, the housing parts may be made of nickel-plated steel, stainless steel (e.g., type 1.4303 or 1.4304), copper, nickel-plated copper, or alloyed or unalloyed aluminum. It may be preferable for the housing part electrically connected to the cathode to be made of aluminum or an aluminum alloy, and for the housing part electrically connected to the anode to be made of copper, a copper alloy, or nickel-plated copper.

[0147] The main advantage of this variant is that it does not require a cup-shaped housing part that must be produced by an upstream forming and / or casting operation to form the housing: instead, a tubular first housing part serves as the starting point.

[0148] In a preferred further development of the second variant, the battery according to the invention has at least one of the following characteristics a. to e., in particular a combination of the following characteristics a. to e.: a. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the anode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. b. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the cathode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. c. One of the contact elements, in particular one of the contact plates, is welded into one of the terminal openings of the first housing part and the second housing part. d. A third housing part is welded into the other of the terminal openings of the first housing part and includes a pole bushing, e.g., a pole stud surrounded by an electrical insulator, through which the conductor is led out of the housing. e. The other of the contact elements, in particular the other of the contact plates, is electrically connected to this electrical conductor.

[0149] It is particularly preferred that the immediately preceding features a. to e. are realized in combination with one another.

[0150] In a further preferred development of the second variant, the battery according to the invention has at least one of the following characteristics a. to d.: a. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the anode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. b. The battery comprises a metallic contact element, in particular a metallic contact plate, with which a first longitudinal edge of the cathode current collector is preferably in direct longitudinal contact, this longitudinal edge being connected to the contact element by welding. c. One of the contact elements, in particular one of the contact plates, is welded into one of the terminal openings of the first housing part and the second housing part. d. The other of the contact elements, in particular the other of the contact plates, closes the other of the terminal openings of the first housing part as a third housing part and is insulated from the first housing part by a seal.

[0151] It is particularly preferred that the immediately preceding features a. to d. be realized in combination with one another.

[0152] Both embodiments are characterized in that, on one side of the housing, the contact elements, in particular the contact plates, function as housing parts and are connected to the first housing part by welding. On the other side, the contact elements, in particular the contact plates, can also function as housing parts. However, the contact elements must then be electrically insulated from the first housing part. Alternatively, pole bushings can also be used here.

[0153] The pole bushings of the batteries according to the invention always comprise an electrical insulator which prevents electrical contact between the housing and the electrical conductors leading out of the housing. The electrical insulator can be, for example, a glass or ceramic material or a plastic.

[0154] The electrode-separator assembly is preferably in the form of a cylindrical winding. Providing the electrodes in such a winding form allows for particularly advantageous utilization of space in a cylindrical housing. Therefore, in a preferred embodiment, the housing is also cylindrical.

[0155] In another preferred embodiment, the electrode-separator assembly is preferably in the form of a prismatic winding. Providing the electrodes in such a winding form allows for particularly advantageous utilization of the space in the prismatic housing. Therefore, in a preferred embodiment, the housing is also prismatic.

[0156] In addition, the prismatic housing can be particularly well filled with a prismatic stack of a plurality of electrode-separator assemblies. To this end, the electrode-separator assemblies can particularly preferably have a substantially rectangular shape.

[0157] The housing parts are preferably sheet metal parts having a thickness in the range of 50 μm to 600 μm, preferably in the range of 150 to 350 μm, and are consequently preferably made of alloyed or unalloyed aluminum, titanium, nickel or copper, optionally also stainless steel (for example type 1.4303 or 1.4304) or nickel-plated steel.

[0158] It should be emphasized that all of the described embodiments in which parts of the housing function as contact elements, in particular contact plates, and / or the contact elements, in particular contact plates, form parts of the housing enclosing the electrode-separator assembly, in particular the first and second contact variants, can also be realized completely independently of feature j of claim 1. The invention therefore also includes batteries having features a to i of claim 1, in which parts of the housing function as contact elements, in particular contact plates, and / or the contact elements, in particular contact plates, form parts of the housing, but the separator does not necessarily comprise at least one inorganic material that improves its resistance to thermal stresses.

[0159] Preferred embodiments of the current collector. In a particularly preferred embodiment, the battery according to the invention is characterized by at least one of the following features a. to c.: a. The strip-shaped main area of ​​the current collector which is connected to the contact element, in particular to the contact plate, by welding, preferably the strip-shaped main area of ​​the current collector which is connected to the contact plate by welding, has a plurality of apertures. b. The apertures in the main area are circular or square holes, especially punched or drilled holes. c. The current collectors, which are connected by welding to the contact elements, in particular to the contact plates, are perforated in the main area, in particular by drilling round holes or slots.

[0160] The multiple apertures result in a reduced current collector volume and therefore weight, which allows for more active material to be introduced into the battery, thus significantly increasing the battery's energy density. In this way, energy density increases up to the double-digit percentage range can be realized.

[0161] In some preferred embodiments, the apertures are introduced into the strip-shaped main area by a laser.

[0162] In principle, the geometry of the apertures is not essential to the invention. What is important is that the insertion of the apertures results in a reduction in the mass of the current collector, allowing the apertures to be filled with active material, so that more space is available for the active material.

[0163] On the other hand, when creating the apertures, it can be very advantageous to ensure that the maximum diameter of the apertures is not too large. Preferably, the apertures should be no more than twice the thickness of the layer of electrode material on each current collector.

[0164] In a particularly preferred embodiment, the battery according to the invention is characterized by the following feature a. The apertures in the current collector, particularly in the main region, have a diameter in the range of 1 μm to 3000 μm. Within this preferred range, diameters in the range of 10 μm to 2000 μm, preferably 10 μm to 1000 μm, and especially 50 μm to 250 μm are particularly preferred.

[0165] Particularly preferably, the battery according to the invention has at least one of the following characteristics a. and b.: a. A current collector that is connected to a contact element, in particular a contact plate, by welding has, in at least a partial section of its main area, a weight per unit area that is smaller than the free edge strip of the same current collector. b. The current collectors connected by welding to the contact elements, in particular to the contact plates, have, in the free edge strips, no apertures or fewer apertures per unit area than in the main area. It is particularly preferred that the immediately preceding features a. and b. are realized in combination with each other.

[0166] The free edge strips of the anode and cathode current collectors delimit the main area towards the first edge or first longitudinal edge. Preferably, both the anode and cathode current collectors include free edge strips along both of their edges, in particular along both of their longitudinal edges.

[0167] The apertures characterize the main region, in other words the boundary between the main region and the free edge strip corresponds to the transition between the apertured and non-apertured regions.

[0168] The apertures are preferably distributed substantially evenly across the main area.

[0169] In a further particularly preferred embodiment, the battery according to the invention has at least one of the following characteristics a. to c.: a. The weight per unit area of ​​the current collector in the main area is reduced by 5% to 80% compared to the weight per unit area of ​​the current collector in the free edge strip. b. The current collector has a hole area in the range of 5% to 80% of the primary area. c. Current collector has a resistance of 20 N / mm 2 ~250N / mm 2 It has a tensile strength of

[0170] The hole area, often referred to as the free cross section, can be determined in accordance with ISO 7806-1983. The tensile strength of the current collector in the main area is reduced compared to a current collector without apertures. Its determination can be made in accordance with DIN EN ISO 527 Part 3.

[0171] The anode and cathode current collectors are preferably identical or similar in terms of aperture, and the improvements in achievable energy density of each are additive. In a preferred embodiment, the battery according to the present invention has at least one of the following characteristics a. to c.: a. The anode current collector main area and the cathode current collector main area, preferably the strip-shaped anode current collector main area and the strip-shaped cathode current collector main area, are both characterized by a plurality of apertures. b. The battery includes as a first contact element or contact plate a contact element, particularly a contact plate, mounted on one of the first edges or longitudinal edges, and further includes a second contact element, particularly a second metallic contact plate, mounted on the other of the first edges or longitudinal edges. c. A second contact element, in particular a second contact plate, is connected to this other longitudinal edge by welding.

[0172] It is particularly preferred that the immediately preceding features a to c are realized in combination with one another, however features b and c may also be realized in combination without feature a.

[0173] The preferred embodiments of the apertured current collector described above are independently applicable to the anode current collector and the cathode current collector.

[0174] The use of perforated or other multi-apertured current collectors has not yet been seriously considered for lithium-ion batteries because it is very difficult to electrically contact such current collectors. As mentioned at the beginning, electrical connection of the current collectors is often achieved via separate conductor tabs. However, in industrial mass-production processes, reliably welding these conductor tabs to perforated current collectors without an acceptable error rate is difficult to achieve.

[0175] According to the present invention, this problem is solved by welding the edge of the current collector to the contact element, in particular the contact plate, as described. The concept according to the present invention makes it possible to completely dispense with a separate conductor tab and thus allows the use of a current collector with a low material content and with apertures. In particular, in embodiments in which the free edge strip of the current collector is not apertured, the welding can be carried out reliably with an extremely low reject rate.

[0176] This is especially true when the edges of the current collector, especially the longitudinal edges of the current collector, are provided with the support layer described above, improving the separator against thermal stresses as described.

[0177] It should be emphasized that all of the described embodiments in which the preferably strip-shaped main region of the current collector, which is connected to the contact elements, in particular the contact plates, by welding, has a plurality of apertures, can be realized completely independently of feature j of claim 1. The invention therefore also includes batteries having features a to i of claim 1, in which the preferably strip-shaped main region of the current collector, which is connected to the contact elements, in particular the contact plates, by welding, has a plurality of apertures, but the separator does not necessarily have to comprise at least one inorganic material that improves its resistance to thermal stresses.

[0178] Other Preferred Embodiments of the Battery The lithium ion battery according to the present invention may be a button battery. The button battery is cylindrical in shape and has a height smaller than its diameter. Preferably, the height is in the range of 4 mm to 15 mm. More preferably, the button battery has a diameter in the range of 5 mm to 25 mm. The button battery is suitable for supplying electrical energy to small electronic devices such as watches, hearing aids, and wireless headphones.

[0179] The nominal capacity of the lithium-ion battery in the form of a button cell according to the invention is generally at most 1500 mAh, preferably in the range of 100 mAh to 1000 mAh, particularly preferably in the range of 100 to 800 mAh.

[0180] Particularly preferably, the lithium ion battery of the present invention is a cylindrical round battery, which has a height greater than its diameter, and is particularly suitable for the automotive sector, electric bicycles or other applications with high energy requirements.

[0181] Preferably, the height of lithium-ion batteries designed as circular batteries is in the range of 15 mm to 150 mm. The diameter of cylindrical circular batteries is preferably in the range of 10 mm to 60 mm. Within these ranges, shape factors of, for example, 18 x 65 (diameter x height, in mm) or 21 x 70 (diameter x height, in mm) are particularly preferred. Cylindrical circular batteries with these shape factors are particularly suitable for powering electric drives in automobiles.

[0182] The nominal capacity of the lithium-ion battery according to the present invention, designed as a cylindrical round battery, is preferably at most 90,000 mAh. In the case of a 21x70 form factor, the battery in one embodiment as a lithium-ion battery preferably has a nominal capacity in the range of 1,500 mAh to 7,000 mAh, particularly preferably in the range of 3,000 to 5,500 mAh. In the case of an 18x65 form factor, the battery in one embodiment as a lithium-ion battery preferably has a nominal capacity in the range of 1,000 mAh to 5,000 mAh, particularly preferably in the range of 2,000 to 4,000 mAh.

[0183] In the European Union, manufacturers are strictly regulated in providing information about the nominal capacity of secondary batteries. For example, information about the nominal capacity of secondary nickel-cadmium batteries must be based on measurements according to the IEC / EN 61951-1 and IEC / EN 60622 standards, information about the nominal capacity of secondary nickel-metal hydride batteries must be based on measurements according to the IEC / EN 61951-2 standard, information about the nominal capacity of secondary lithium batteries must be based on measurements according to the IEC / EN 61960 standard, and information about the nominal capacity of secondary lead-acid batteries must be based on measurements according to the IEC / EN 61056-1 standard. Any information about nominal capacity in this application is preferably based on these standards.

[0184] In embodiments in which the battery according to the present invention is a cylindrical round battery, the anode current collector, cathode current collector and separator are preferably ribbon-shaped and preferably have the following dimensions: Length ranging from 0.5m to 25m, Width ranges from 30mm to 145mm.

[0185] In these cases, the free edge strip extending along the first longitudinal edge and not provided with electrode material preferably has a width of 5000 μm or less.

[0186] For cylindrical round cells with a form factor of 18x65, the current collector preferably has: Width of 56mm to 62mm, preferably 60mm; Length less than 1.5m.

[0187] For cylindrical round cells with a 21x70 form factor, the current collector preferably has: a width of 56 mm to 68 mm, preferably 65 mm, and Length less than 2.5m.

[0188] The functionality of a lithium-ion battery is based on the availability of sufficient mobile lithium ions (mobile lithium) to balance the current drawn by migration between the anode and cathode or between the negative and positive electrodes. In the context of this application, mobile lithium should be understood to mean that lithium is available in the electrode for storage and release processes or can be activated for this purpose during the discharge and charge processes of a lithium-ion battery. During the discharge and charge processes of a lithium-ion battery, losses of mobile lithium occur over time. These losses occur as a result of various, usually unavoidable, side reactions. Losses of mobile lithium already occur during the first charge and discharge cycles of a lithium-ion battery. During these first charge and discharge cycles, an overlayer typically forms on the surface of the electrochemically active component on the negative electrode. This overlayer, referred to as a solid electrolyte interlayer (SEI), typically consists primarily of electrolyte decomposition products and a certain amount of lithium firmly bound within the layer.

[0189] The loss of mobile lithium associated with this process is particularly severe in batteries in which the anode has a certain amount of silicon. To compensate for these losses, the battery according to the invention in a preferred embodiment has at least one of the following characteristics a. and b.: a. The battery includes a reservoir of lithium or lithium-containing material not contained by the positive and / or negative electrodes, which can be used to compensate for the loss of mobile lithium in the battery during operation. b. The reservoir is in contact with the battery's electrolyte. c. The battery comprises an electrical conductor and optionally further a controllable switch through which the reservoir can be electrically connected to the positive or negative electrode. It is particularly preferable that the immediately preceding features a to c be realized in combination with one another.

[0190] Particularly preferably, the reservoir is arranged inside the housing of the battery according to the invention, and the electrical conductors are led out of the housing, for example via suitable pole bushings, and in particular to electrical contacts which can be brought out to the outside of the housing.

[0191] The electrically accessible lithium reservoir allows for the supply of lithium to the battery's electrodes or the removal of excess lithium from the electrodes to prevent lithium plating, as needed. For this purpose, the lithium reservoir can be connected via an electrical conductor to the negative or positive electrode of the lithium-ion battery. Excess lithium can be supplied to the lithium reservoir and deposited there, as needed. For these applications, means can be provided to allow separate monitoring of the individual potentials of the anode and cathode within the battery and / or external monitoring of the battery balance via electrochemical analysis, such as DVA (differential voltage analysis).

[0192] The electrical conductors and associated lithium reservoirs must be electrically isolated from the positive and negative electrodes and any electrically coupled components of the battery.

[0193] The lithium or lithium-containing material of the lithium reservoir can be, for example, metallic lithium, lithium metal oxide, lithium metal phosphate, or other materials well known to those skilled in the art.

[0194] Prism embodiment The present invention also includes an energy storage element that includes a stack of multiple anodes and multiple cathodes enclosed within a prismatic housing.

[0195] In particular, the present invention therefore also includes an energy storage element having the following characteristics a. to k.: a. the energy storage element includes a plurality of anodes and cathodes; b. the anodes each comprise an anode current collector and a negative electrode material; c. each of the anode current collectors is a main area provided with a layer of negative electrode material, and a free edge strip extending along the edge of the anode current collector on which no negative electrode material is provided; d. the cathodes each comprise a cathode current collector and a positive electrode material; e. The cathode current collector is a main area provided with a layer of positive electrode material, and A free edge strip extending along the edge of the cathode current collector on which no positive electrode material is provided. each of which has f. the anode and cathode are stacked, the anode and cathode in the stack being separated by a separator; g. The stack is enclosed within a prismatic housing; h. a free edge strip of the anode current collector protruding from one side of the stack and a free edge strip of the cathode current collector protruding from another side of the stack; i. the energy storage element has contact elements that directly contact the free edge strips of the anode current collector and / or the cathode current collector; and j. the contact element is connected to the edge strip by welding; and Additional Distinguishing Features k. The separator includes at least one inorganic material that improves its resistance to thermal stress.

[0196] The same preferred developments apply to the layer of negative electrode material, the layer of positive electrode material and the current collector as in the lithium-ion battery according to the invention, and the same also applies to the electrolyte if the energy storage element comprises an electrolyte, and in particular also to the separator and the at least one inorganic material.

[0197] Preferably, the energy storage element is characterized by at least one of the following additional features: a. The separator comprises at least one inorganic material only in regions. b. The separators each have an edge strip, in which the separator includes at least one inorganic material as a coating and / or particulate filler material. c. The separator has at least one primary region that is free of inorganic material.

[0198] Particularly preferably, the energy storage element comprises two contact elements, one of which is in direct contact with the free edge strip of the anode current collector and the other of which is in direct contact with the free edge strip of the cathode current collector, the contact elements and the edges in contact with them being connected by welding or soldering, respectively.

[0199] In the manufacture of conventional electrode stacks consisting of several cells, care is taken to ensure that the blocks connecting the current collectors with opposite polarity cannot protrude into each other in order to avoid the risk of short circuits. According to the present invention, the free edge strip of the anode current collector protrudes from one side of the stack and the free edge strip of the cathode current collector protrudes from the other side of the stack, so that in the energy storage element according to the present invention there is usually no risk of short circuits as a result of direct contact of current collectors of opposite polarity.

[0200] The contact elements function as central conductors for the current drawn from the electrodes during operation of the energy storage element. Here, the free edge strips of the anode and cathode current collectors are ideally connected to the contact elements along their entire length. Such electrical contact significantly reduces the internal resistance within the energy storage element according to the invention. The described arrangement is therefore very well able to absorb the generation of large currents. Because the internal resistance is minimized, heat losses at high currents are reduced. Additionally, dissipation of thermal energy from the assembly is desirable. Therefore, under high loads, heating is not localized but rather uniformly distributed.

[0201] In some preferred embodiments, the energy storage element according to the present invention has at least one of the following characteristics a. and b.: a. Metal sheets having a thickness in the range of 50 μm to 600 μm, preferably 150 to 350 μm, are used as contact elements. b. The contact elements, in particular the metal sheets, consist of alloyed or unalloyed aluminum, titanium, nickel or copper or stainless steel (for example type 1.4303 or 1.4304) or nickel-plated steel. Preferably, the immediately preceding features a. and b. are realized in combination with each other.

[0202] The shape and dimensions of the contact elements, in particular the metal sheets, preferably match the shape and dimensions of the sides of the assembly, from which the free edge strips of the current collectors are formed. In a preferred embodiment, the contact elements are rectangular in shape. They can therefore be incorporated into a housing having a prismatic basic shape.

[0203] In particularly preferred embodiments, the energy storage element according to the invention is characterized by at least one of the following features: a. The energy storage element includes at least one contact element having an L-shaped profile. b. The energy storage element includes at least one contact element having a U-shaped profile. c. The contact element has a bent mounting extension. Preferably, the immediately preceding features a. and c. or b. and c. are combined.

[0204] If contact elements with an L-shaped profile are used, the protruding edge strips of each current collector can be contacted on both sides of the assembly. For this purpose, it is of course necessary that the electrodes of the assembly comprise two edges, whereby their current collectors first have a free edge area accessible for welding or soldering.

[0205] When the contact elements have a U-shaped profile, it is generally considered that contact to the protruding edges of the respective current collectors occurs on three sides of the assembly. When curved fastening extensions are provided, they are primarily intended for fastening the contact elements to the housing of the energy storage element, if the contact elements themselves are not part of the housing. Furthermore, the fastening extensions may be part of an L-shaped or U-shaped profile and may also be used, for example, to attach pole studs.

[0206] The more sides of the assembly that are provided with contact elements, the better the heat dissipation characteristics of the energy storage element.

[0207] The prismatic housing of the energy storage element preferably encloses the assembly in an airtight and / or liquid-tight manner. The prismatic housing is preferably formed from two or more metallic housing parts, for example as described in EP 3117471 B1. The housing parts may be assembled, for example, by welding.

[0208] The housing preferably comprises several rectangular side walls and a polygonal, in particular rectangular, bottom and a polygonal, in particular rectangular, top, which in particular can also function as contact elements, preferably contact plates.

[0209] Further features of the present invention and advantages arising from the present invention can be seen from the drawings and the following description of the drawings. The following embodiments merely serve to explain the present invention and provide a better understanding of the present invention, and should not be understood as limiting in any way. [Brief explanation of the drawings]

[0210] [Figure 1] FIG. 2 is a top view of a current collector in one embodiment according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the current collector shown in FIG. [Figure 3]FIG. 1 is a top view of an anode that can be processed and placed into an electrode-separator assembly in the form of a winding. [Figure 4] FIG. 4 is a cross-sectional view of the anode shown in FIG. [Figure 5] FIG. 4 is a top view of an electrode-separator assembly fabricated using the anode shown in FIG. 3. [Figure 6] FIG. 6 is a cross-sectional view of the electrode-separator assembly shown in FIG. 5. [Figure 7] 1 is a cross-sectional view of one embodiment of a battery according to the present invention in the form of a cylindrical round battery. [Figure 8] 1 is a cross-sectional view of a further embodiment of a battery according to the invention in the form of a cylindrical round battery. [Figure 9] 1 is a cross-sectional view of a further embodiment of a battery according to the invention in the form of a cylindrical round battery. [Figure 10] 1 is a cross-sectional view of a further embodiment of a battery according to the invention in the form of a cylindrical round battery. [Figure 11] 1 is a cross-sectional view of a further embodiment of a battery according to the invention in the form of a cylindrical round battery. [Figure 12] 12 is a diagram of a method for manufacturing the battery according to the present invention shown in FIG. 11. DETAILED DESCRIPTION OF THE INVENTION

[0211] 1 and 2 show designs of a current collector 110 that can be used in a battery according to the present invention. FIG. 2 is a cross-sectional view along S1. The current collector 110 includes a plurality of apertures 111, which are rectangular holes. Region 110a is characterized by apertures 111, while region 110b along longitudinal edge 110e is aperture-free. Thus, the current collector 110 has a significantly lower weight per unit area in region 110a than in region 110b.

[0212] 3 and 4 show an anode 120 made by applying negative electrode material 123 to both sides of the current collector 110 shown in FIGS. 2 and 3. FIG. 4 is a cross-sectional view along S2. Here, the current collector 110 includes a strip-shaped main region 122 provided with a layer of negative electrode material 123, and a free edge strip 121 extending along the longitudinal edge 110e that is free of electrode material 123. Furthermore, the electrode material 123 also fills the apertures 111.

[0213] 5 and 6 show an electrode-separator assembly 104 made using the anode 120 shown in FIGS. 3 and 4. The electrode-separator assembly additionally includes a cathode 115 and separators 118 and 119. FIG. 6 is a cross-sectional view along S3. The cathode 115 is constructed based on the same current collector design as the anode 120. Preferably, the current collectors 110 and 115 of the anode 120 and cathode 130 differ only in their respective material selection. For example, the current collector 115 of the cathode 130 includes a strip-shaped main region 116 provided with a layer of positive electrode material 125 and a free edge strip 117 extending along a longitudinal edge 115e that is free of electrode material 125. The electrode-separator assembly 104 can be transformed into a winding by spirally winding it, which can be included in a battery of the present invention.

[0214] In some preferred embodiments, the free edge strips 117 and 121 are coated on both sides and in at least some areas with an electrically insulating support material, for example a ceramic material such as silicon oxide or aluminum oxide.

[0215] 7 shows a battery 100 having a housing including a first housing part 101 and a second housing part 102. An electrode-separator assembly 104 is enclosed within the housing. The housing is generally cylindrical in shape, with housing part 101 having a circular bottom 101a, a hollow cylindrical shell 101b, and a circular opening opposite the bottom 101a. Housing part 102 serves to close the circular opening and is formed as a circular lid. The electrode-separator assembly 104 is in the form of a cylindrical winding with two terminal end faces.

[0216] In the case of a prismatic embodiment, the cross section through the energy storage element may look exactly the same. In this case, housing part 101 would have a rectangular bottom 101a, rectangular side walls 101b and a rectangular cross section as well as a rectangular opening, and housing part 102 would be formed as a rectangular lid for closing the rectangular opening. In this case, reference number 104 does not refer to a cylindrical electrode-separator assembly, but to a stack of multiple identical electrode-separator assemblies.

[0217] A free edge strip 121 of the anode current collector 110 protrudes from one end face of the electrode-separator assembly 104, and a free edge strip 117 of the cathode current collector 115 protrudes from the other end face. The edge 110e of the anode current collector 110 directly contacts the bottom 101a of the housing part 101 along its entire length and is connected to the bottom by welding over at least some sections, preferably over its entire length. The edge 115e of the cathode current collector 115 directly contacts the contact plate 105 along its entire length and is connected to the contact plate by welding over at least some sections, preferably over its entire length.

[0218] The contact plate 105 is thereby electrically connected to the housing part 102 via the conductor 107. Preferably, there is a welded connection between the conductor 107 and the contact plate 105 on one side and between the conductor 107 and the housing part 102 on the other side.

[0219] For better overview, except for current collectors 110 and 115, no other components of electrode-separator assembly 104 (notably separator and electrode materials) are shown.

[0220] The housing parts 101 and 102 are electrically insulated from each other by a seal 103. The housing is closed, for example, by flanging. The housing part 101 forms the cathode of the battery 100, and the housing part 102 forms the anode.

[0221] 8 shows a battery 100 having a housing including a first housing part 101 and a second housing part 102. An electrode-separator assembly 104 is enclosed within the housing. The housing is generally cylindrical in shape, with housing part 101 having a circular bottom 101a, a hollow cylindrical shell 101b, and a circular opening opposite the bottom 101a. Housing part 102 serves to close the circular opening and is formed as a circular lid. The electrode-separator assembly 104 is in the form of a cylindrical winding with two terminal end faces.

[0222] In the case of a prismatic embodiment, the cross section through the energy storage element may look exactly the same. In this case, housing part 101 would have a rectangular bottom 101a, rectangular side walls 101b and a rectangular cross section as well as a rectangular opening, and housing part 102 would be formed as a rectangular lid for closing the rectangular opening. In this case, reference number 104 does not refer to a cylindrical electrode-separator assembly, but to a stack of multiple identical electrode-separator assemblies.

[0223] A free edge strip 121 of the anode current collector 110 protrudes from one end face of the electrode-separator assembly 104, and a free edge strip 117 of the cathode current collector 115 protrudes from the other end face. The edge 110e of the anode current collector 110 directly contacts the bottom 101a of the housing part 101 along its entire length and is connected to the bottom by welding over at least some sections, preferably over its entire length. The edge 115e of the cathode current collector 115 directly contacts the contact plate 105 along its entire length and is connected to the contact plate by welding over at least some sections, preferably over its entire length.

[0224] The contact plate 105 is directly connected, preferably welded, to a metallic pole stud 108. The pole stud is led out of the housing through an aperture in the housing part 102 and is insulated from the housing part 102 by an electrical insulator 106. The pole stud 108 and the electrical insulator 106 together form a pole bushing.

[0225] Again, for improved overview, except for current collectors 110 and 115, no other components of electrode-separator assembly 104 (particularly separator and electrode materials) are shown.

[0226] The bottom 101a has a hole 109, which can be closed, for example by soldering, welding or bonding, and which can be used, for example, to introduce an electrolyte into the housing. Alternatively, a hole can be made in the housing part 102 for the same purpose.

[0227] Housing part 102 is welded into the circular opening in housing part 101. Housing parts 101 and 102 therefore have the same polarity and form the negative pole of battery 100. Polarity stud 108 forms the positive pole of battery 100.

[0228] 9 shows a battery 100 having a housing including a first housing part 101 and a second housing part 102. An electrode-separator assembly 104 is enclosed within the housing. The housing is generally cylindrical in shape, with housing part 101 having a circular bottom 101a, a hollow cylindrical shell 101b, and a circular opening opposite the bottom 101a. Housing part 102 serves to close the circular opening and is formed as a circular lid. The electrode-separator assembly 104 is in the form of a cylindrical winding with two terminal end faces.

[0229] In the case of a prismatic embodiment, the cross section through the energy storage element may look exactly the same. In this case, housing part 101 would have a rectangular bottom 101a, rectangular side walls 101b and a rectangular cross section as well as a rectangular opening, and housing part 102 would be formed as a rectangular lid for closing the rectangular opening. In this case, reference number 104 does not refer to a cylindrical electrode-separator assembly, but to a stack of multiple identical electrode-separator assemblies.

[0230] A free edge strip 121 of the anode current collector 110 protrudes from one end face of the electrode-separator assembly 104, and a free edge strip 117 of the cathode current collector 115 protrudes from the other end face. The edge 110e of the anode current collector 110 directly contacts the bottom 101a of the housing part 101 along its entire length and is connected to the bottom by welding over at least some sections, preferably over its entire length. The edge 115e of the cathode current collector 115 directly contacts the housing part 102 along its entire length and is connected to the housing part by welding over at least some sections, preferably over its entire length.

[0231] Again, for improved overview, except for current collectors 110 and 115, no other components of electrode-separator assembly 104 (particularly separator and electrode materials) are shown.

[0232] In the bottom 101a, a hole 109 is visible which is closed, for example, by soldering, welding or bonding, and which may serve, for example, to introduce an electrolyte into the housing. In the housing part 102, another hole 109 is visible which may serve the same purpose. Preferably, this hole is closed by a pressure regulating valve 141 which may, for example, be welded onto the housing part 102.

[0233] The holes 109 shown are generally not both required, so in most cases the battery 100 shown in Figure 9 will only have one of the two holes.

[0234] The housing parts 101 and 102 are electrically insulated from each other by a seal 103. The housing is closed, for example, by flanging. The housing part 101 forms the cathode of the battery 100, and the housing part 102 forms the anode.

[0235] 10 shows a battery 100 having a housing including a first housing part 101, a second housing part 102, and a third housing part 155. An electrode-separator assembly 104 is enclosed within the housing. The housing has an overall cylindrical shape, with housing part 101 here formed as a hollow cylinder with two end circular openings. Housing parts 102 and 155 serve to close the circular openings and are formed as circular lids. The electrode-separator assembly 104 is in the form of a cylindrical winding with two terminal end faces.

[0236] In the case of a prismatic embodiment, the cross section through the energy storage element may look exactly the same. In this case, housing part 101 would have a rectangular cross section and two rectangular openings, and housing parts 102 and 155 would be rectangular lids closing the rectangular openings. In this case, reference number 104 does not refer to a cylindrical electrode-separator assembly, but to a stack of several identical electrode-separator assemblies.

[0237] The free edge strip 121 of the anode current collector 110 protrudes from one end face of the electrode-separator assembly 104, and the free edge strip 117 of the cathode current collector 115 protrudes from the other end face. The edge 110e of the anode current collector 110 is in direct contact with the housing part 155 over its entire length and is connected to the housing part by welding at least in some sections, preferably over its entire length. The housing part 155 therefore functions as a contact plate within the meaning of the present invention. The edge 115e of the cathode current collector 115 is in direct contact with the contact plate 105 over its entire length and is connected to the contact plate by welding at least in some sections, preferably over its entire length.

[0238] Again, for improved overview, except for current collectors 110 and 115, no other components of electrode-separator assembly 104 (particularly separator and electrode materials) are shown.

[0239] The contact plate 105 is directly connected, preferably welded, to a metallic pole stud 108. The pole stud is led out of the housing through an aperture in the housing part 102 and is insulated from the housing part 102 by an electrical insulator 106. The pole stud 108 and the electrical insulator 106 together form a pole bushing.

[0240] Housing part 102 has a hole 109 which can be closed, for example by soldering, welding or bonding, and which can be used, for example, to introduce an electrolyte into the housing. Alternatively, a hole can be made in housing part 155 for the same purpose.

[0241] Housing parts 102 and 155 are welded into the circular opening in housing part 101. Housing parts 101, 102 and 155 therefore have the same polarity and form the negative pole of battery 100. Polarity stud 108 forms the positive pole of battery 100.

[0242] FIG. 11 shows a battery 100 having a housing including a first housing part 101 and a second housing part 102. An electrode-separator assembly 104 is enclosed within the housing. The housing is generally cylindrical in shape, with housing part 101 having a circular bottom 101a, a hollow cylindrical shell 101b, and a circular opening opposite the bottom 101a. Housing part 102 serves to close the circular opening and is formed as a circular lid. The electrode-separator assembly 104 is in the form of a cylindrical winding with two terminal end faces.

[0243] In the case of a prismatic embodiment, the cross section through the energy storage element may look exactly the same. In this case, housing part 101 would have a rectangular bottom 101a, rectangular side walls 101b and a rectangular cross section as well as a rectangular opening, and housing part 102 would be formed as a rectangular lid for closing the rectangular opening. In this case, reference number 104 does not refer to a cylindrical electrode-separator assembly, but to a stack of multiple identical electrode-separator assemblies.

[0244] A free edge strip 121 of the anode current collector 110 protrudes from one end face of the electrode-separator assembly 104, and a free edge strip 117 of the cathode current collector 115 protrudes from the other end face. An edge 110e of the anode current collector 110 is in direct contact with the bottom 101a of the housing part 101 over its entire length and is connected to that bottom by welding over at least some sections, preferably over its entire length.

[0245] The edge 115e of the cathode current collector 115 is in direct contact with the housing part 102 over its entire length and is connected to the housing part by welding at least in some sections, preferably over its entire length, so that the housing part 102 now simultaneously functions as a contact plate.

[0246] The anode current collector 110 has a layer of negative electrode material 123 provided thereon, but has free edge strips 121 extending along the longitudinal edges 110e on both sides that are free of electrode material 123. Instead, the free edge strips 121 are coated on both sides with ceramic support material 165.

[0247] The cathode current collector 115 is provided with a layer of negative electrode material 125, but has free edge strips 117 on both sides extending along the longitudinal edges 115e that are free of electrode material 125. Instead, the free edge strips 117 are coated with ceramic support material 165 on both sides.

[0248] In a preferred embodiment, as shown for example in Figures 1 and 2, the current collectors 110 and 115 may be perforated in the areas where the electrode materials 123 and 125 are provided.

[0249] The electrode-separator assembly 104 has two end faces formed by longitudinal edges 118a and 119a and 118b and 119b of separators 118 and 119. The longitudinal edges of current collectors 110 and 115 protrude from these end faces. The corresponding protrusions are labeled d1 and d2.

[0250] Separators 118 and 119 each have at least one surface that includes a ceramic coating or each includes a ceramic filler material that improves its resistance to thermal stresses.

[0251] A hole 109 is visible in the housing part 102, which can be used, for example, to introduce an electrolyte into the housing. The hole is closed by a pressure regulating valve 141, which is connected to the housing part 102, for example, by welding.

[0252] The housing parts 101 and 102 are electrically insulated from each other by a seal 103. The housing is closed by flanging. For this purpose, the opening edges 101c of the housing parts are bent radially inwards. The housing part 101 forms the cathode of the battery 100, and the housing part 102 forms the anode.

[0253] The battery shown in FIG. 11 can be manufactured according to FIG. 12, with the individual process steps A to I described below. First, an electrode-separator assembly 104 is provided, and a housing part 102, which functions as a contact plate, is placed on its upper end face. In step B, the housing part is welded to the longitudinal edge 115e of the cathode current collector 115. In step C, a circumferential seal 103 is applied to the edge of the housing part 102. Using this, in step D, the electrode-separator assembly 104 is inserted into the housing part 101 until the longitudinal edge 110e of the anode current collector 110 directly contacts the bottom 101a of the housing part 101. In step E, the longitudinal edge 110e is welded to the bottom 101a of the housing part 101. In step F, the housing is closed by flanging. For this purpose, the opening edge 101c of the housing part 101 is bent radially inward. In step G, the housing is filled with electrolyte, which is metered into the housing through opening 109. Opening 109 is closed in steps H and I by pressure regulating valve 141 welded onto housing part 102.

[0254] For example, the electrode-separator assembly 104 may include a positive electrode that includes 95% by weight NMCA, 2% by weight electrode binder, and 3% by weight carbon black as a conductive agent.

[0255] In some preferred embodiments, the negative electrode may contain, for example, 70 wt. % silicon as a conductive agent, 25 wt. % graphite, 2 wt. % electrode binder, and 3 wt. % carbon black. The electrolyte may be a 2 M solution of LiPF in THF / mTHF (1:1) or a 1.5 M solution of LiPF in FEC / EMC (3:7) with 2 wt. % VC.

[0256] Many other preferred embodiments use anodes with a high proportion of carbon-based storage material and a silicon / silicon oxide content of less than 10% by weight, and in these cases, conventional electrolytes in which conductive salts are dissolved in a mixture of organic carbonates are often used.

Claims

1. A lithium ion battery (100) comprising: a. the battery includes a ribbon-shaped electrode-separator assembly (104) having an anode (120) / separator (118) / cathode (130) arrangement; b. the anode (120) comprises a negative electrode material (123) and a ribbon-shaped anode current collector (110) having a first longitudinal edge (110e) and a second longitudinal edge and two end portions; c) the anode current collector (110) has a strip-shaped main area (122) provided with a layer of the negative electrode material (123) and a free edge strip (121) extending along the first longitudinal edge (110e) and not provided with the negative electrode material (123); d. the cathode (130) comprises a positive electrode material (125) and a ribbon-shaped cathode current collector (115) having a first longitudinal edge (115e) and a second longitudinal edge and two ends; e. the cathode current collector (115) has a strip-shaped main region (116) provided with a layer of positive electrode material (125) and a free edge strip (117) extending along the first longitudinal edge (115e) and not provided with the positive electrode material (125); f. The electrode-separator assembly (104) is in the form of a winding having two terminal end faces; g. The electrode-separator assembly (104) is enclosed within a housing; h. the anode (120) and the cathode (130) are offset within the electrode-separator assembly (104), such that the first longitudinal edge (110e) of the anode current collector (110) protrudes from one of the terminal end faces, and the first longitudinal edge (115e) of the cathode current collector (115) protrudes from the other of the terminal end faces; i. the battery has a metallic contact element (101a, 102, 155) in direct contact with one of the first longitudinal edges (110e, 115e); j) said contact elements (101a, 102, 155) are connected to said longitudinal edges (110e, 115e) by welding; k. said separator (118) comprising at least one inorganic material that improves its resistance to thermal stresses; l. the at least one inorganic material is present as a coating on the surface of the separator (118). m. The free edge strip (121) of the anode current collector (110) and / or the free edge strip (117) of the cathode current collector (115) is coated with a support material (165) different from the negative electrode material (123) or the positive electrode material (125) disposed on the respective current collector. n. the free edge strip (121) of the anode current collector (110) and / or the free edge strip (117) of the cathode current collector (115) is coated with the support material (165) up to the first longitudinal edge (110e, 115e); o. the separator (118) comprises the at least one inorganic material in a region covering the interface between the support material and the negative electrode material of the electrode-separator assembly (104); A lithium ion battery (100) having:

2. Additional features include: a. the electrode-separator assembly (104) additionally comprises a second separator (119); b. The separator (118) and the separator (119) are identical; c. The electrode-separator assembly (104) has an arrangement of anode (120) / separator (118) / cathode (130) / separator (119) or an arrangement of separator (119) / anode (120) / separator (118) / cathode (130).

10. The battery of claim 1, wherein

3. Additional features include: a. the separator (118) is a ribbon-shaped plastic substrate having a thickness in the range of 5 μm to 50 μm and having first and second longitudinal edges and two end portions; b. the longitudinal edges of the separator (118) form the terminal end faces of the electrode-separator assembly (104); 3. The battery of claim 1 or 2, comprising:

4. Additional features include: a. the at least one inorganic material is contained in the separator (118) as a particulate filler material; The battery according to any one of claims 1 to 3, comprising:

5. Additional features include: a. the at least one inorganic material is or comprises an electrically insulating material; b) the at least one inorganic material is or comprises at least one material selected from the group consisting of a ceramic material, a glass-ceramic material, and a glass; c. the at least one inorganic material is or comprises a lithium ion conducting ceramic material; d. the at least one inorganic material is or comprises an oxide material; e. The ceramic or oxide material is aluminum oxide (Al ２ O ３ ), titanium oxide (TiO ２ ), titanium nitride (TiN), titanium aluminum nitride (TiAlN), silicon oxide, silicon dioxide (SiO ２ ), or titanium carbonitride (TiCN) The battery according to any one of claims 1 to 4, comprising at least one of:

6. Additional features include: a. the separator (118) comprises the at least one inorganic material only in regions; b. the separator (118) has an edge strip along the first longitudinal edge and / or the second longitudinal edge, the edge strip including the at least one inorganic material as a coating and / or particulate filler material; c) the separator (118) has a ribbon-shaped main region, the main region being free of the at least one inorganic material; The battery according to any one of claims 1 to 5, comprising at least one of the following:

7. Additional features include: a. the free edge strip (121) of the anode current collector (110) and / or the free edge strip (117) of the cathode current collector (115) comprises a first sub-region and a second sub-region, the first sub-region being coated with the support material (165) while the second sub-region is not coated; b. the first sub-region and the second sub-region each have the shape of a line or strip and extend parallel to each other; c) the first sub-region is disposed between the strip-shaped main region of the anode current collector (110) or the cathode current collector (115) and the second sub-region; The battery according to any one of claims 1 to 6, comprising at least one of:

8. Additional features include: a. the separator (118) comprises the at least one inorganic material only in regions; The battery according to any one of claims 1 to 7, comprising:

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