Rechargeable Battery Cell

Abstract

The present invention relates to a rechargeable battery cell (2, 20, 40) comprising an active metal, at least one positive electrode (4, 23, 44) having a conductor element (26), at least one negative electrode (5, 22, 45) having a conductor element (27), a housing (1, 28) and an electrolyte, wherein the conductor element (26) of the positive electrode (4, 23, 44) and the conductor element (27) of the negative electrode (5, 22, 45) are formed independently of one another by a material selected from the group formed by aluminum and copper, the electrolyte is based on SO2 and comprises at least one first conductive salt having formula (I), M is a metal selected from the group formed by alkali metals, alkaline earth metals, metals of group 12 of the periodic table of the elements and aluminum, x is an integer from 1 to 3 and is characterized by a substituent R 1 , R 2 , R 3 and R 4 are C1 to C 10 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C3-C 10 Cycloalkyl, C6-C 14 Aryl and C5-C 14 heteroaryl; and Z is aluminum or boron. [Formula 1] JPEG2024504477000014.jpg42166

Description

[Technical field]

[0001] The present invention relates to a rechargeable battery cell having an SO2-based electrolyte. [Background technology]

[0002] Rechargeable battery cells are of great importance in many technical fields. In many cases, they are used in applications where only small rechargeable battery cells with relatively low currents are needed, such as for example the operation of mobile phones. However, there is also a demand for larger rechargeable battery cells for high energy applications, and for the electric drive of vehicles, it is especially important to store large amounts of energy in the form of battery cells.

[0003] An important requirement for this type of rechargeable battery cell is a high energy density, which means that the rechargeable battery cell must contain as much electrical energy as possible per unit of weight and volume. For this purpose, lithium has proven to be particularly advantageous as an active metal. Rechargeable battery cells containing lithium as an active metal are also called lithium-ion batteries. It is possible to increase the energy density of such lithium-ion batteries either by increasing the specific capacity of the electrodes or by increasing the cell voltage.

[0004] Both the positive and negative electrodes of a lithium-ion battery are formed as insertion electrodes. The term "insertion electrode" in the context of the present invention is understood to be an electrode having a crystalline structure in which ions of the active metal can be stored or released during operation of the lithium-ion battery. The active metal of a rechargeable battery cell refers to a metal whose ions in an electrolyte migrate to the negative or positive electrode during charging and discharging of the cell and participate there in electrochemical processes. In the case of an insertion electrode, it is meant that electrode processes can take place not only on the surface of the electrode but also within the crystalline structure. During charging of the lithium-ion battery, ions of the active metal are released from the positive electrode and stored in the negative electrode. During discharging of the lithium-ion battery, the reverse process takes place. The electrochemical process leads directly or indirectly to the release of electrons to or the acceptance of electrons from an external circuit. In order to enable the electrons to be released to or accepted from the external circuit, the positive and negative electrodes of the lithium-ion battery each have a conductor element. The conductor element is an essential component of the positive and negative electrodes. The electrons released in the electrode reaction at the first electrode (e -) are released to the external circuit via their conductor elements. The electrons required for the electrode reaction of the second electrode are supplied from the external circuit by the conductor elements of this electrode. A good electronic conductivity of the two conductor elements is the prerequisite for a high current carrying capacity of the electric cell. The conductor elements can be planar, for example in the form of a metal sheet, or three-dimensional, for example in the form of a porous metal foam. The active material of the negative electrode or the positive electrode is introduced into the metal foam or applied onto the metal sheet. The active material in the metal foam and the coating of the planar metal sheet with the active material are porous, so that the electrolyte used can penetrate into the respective porous structure and thus come into contact with the respective conductor element. A potential difference is created between the electrodes during charging or discharging of the battery cell. The reaction of the conductor elements with the electrode active material or with the electrolyte can be promoted by this potential difference. The material of the conductor elements must therefore be inert to the electrolyte used as well as to the electrode active material used without undesired side reactions occurring in the corresponding potential range. Thus, the electrolyte used and the expected potential range must be taken into account when selecting a suitable conductor element. In the following text, the terms "conductor element", "conductor means" and "current conductor means" are synonymous.

[0005] The electrolyte is also an important functional element for a rechargeable battery cell. The electrolyte usually comprises a solvent or a mixture of solvents and at least one conductive salt. For example, a solid electrolyte or an ionic solution does not comprise a solvent and only comprises the conductive salt. The electrolyte is in contact with the positive and negative electrodes of the battery cell. At least one ion (anion or cation) of the conductive salt is mobile in the electrolyte so that the charge transport between the electrodes, which is necessary for the functioning of the rechargeable battery cell, can be carried out by ionic conduction. The electrolyte is electrochemically decomposed oxidatively above a certain upper cell voltage limit of the rechargeable battery cell. This process often leads to irreversible destruction of the electrolyte components and thus to the failure of the rechargeable battery cell. Reductive processes can also destroy the electrolyte below a certain lower cell voltage limit. To avoid this process, the positive and negative electrodes are selected such that the cell voltage is lower or higher than the decomposition voltage of the electrolyte. The electrolyte thus determines the voltage window (in English: voltage window) within which the rechargeable battery cell can be operated reversibly, ie repeatedly charged or discharged.

[0006] Lithium ion batteries known from the prior art contain an electrolyte consisting of an organic solvent or solvent mixture and a conductive salt dissolved therein. The conductive salt is for example a lithium salt such as lithium hexafluorophosphate (LiPF6). The solvent mixture may for example contain ethylene carbonate. The electrolyte LP57 with the composition 1M LiPF6 in EC:EMC 3:7 is an example of such an electrolyte. By using the organic solvent or solvent mixture, this type of lithium ion battery is also called organic lithium ion battery.

[0007] Besides lithium hexafluorophosphate (LiPF6), which is frequently used as a conductive salt in the prior art, other conductive salts for organic lithium-ion batteries have been described. For example, in Japanese Patent No. 4306858 (hereinafter referred to as [V1]), conductive salts in the form of tetraalkoxy salts or tetraaryloxyborate salts, which may be fluorinated or partially fluorinated, are described. In Japanese Patent Publication No. 2001-143750 (hereinafter referred to as [V2]), fluorinated or partially fluorinated tetraalkoxyborates and tetraalkoxyaluminates are mentioned as conductive salts. The conductive salts described in both documents [V1] and [V2] are dissolved in an organic solvent or solvent mixture and used in organic lithium-ion batteries.

[0008] It has long been known that unintentional overcharging of organic lithium-ion batteries leads to irreversible decomposition of electrolyte components. In this case, oxidative decomposition of the organic solvent and / or the conductive salt occurs at the surface of the positive electrode. The reaction heat formed during the decomposition and the gaseous products generated during this process are the cause of the subsequent so-called "thermal runaway" and thus the destruction of the organic lithium-ion battery. Most charging protocols for organic lithium-ion batteries use the cell voltage as an indicator of the end of charge. Thermal runaway accidents are particularly likely to occur when using multi-cell battery packs in which several organic lithium-ion batteries of different capacities are connected in series.

[0009] Organic lithium-ion batteries therefore have problems with regard to their own stability and operational safety during long-term use. Safety risks also arise in particular due to the flammability of the organic solvent or solvent mixture. If an organic lithium-ion battery were to catch fire or even explode, the organic solvent of the electrolyte would form flammable materials. In order to avoid such safety risks, further measures must be implemented. These include in particular very precise control of the charging and discharging processes of the organic lithium-ion battery and optimization of the battery structure. Furthermore, the organic lithium-ion battery contains components that melt during an unintended temperature increase, which can fill the organic lithium-ion battery with molten plastic. This avoids further uncontrollable temperature increases. However, these measures lead to increased production costs and increased volume and weight during the manufacture of the organic lithium-ion battery. Furthermore, these measures reduce the energy density of the organic lithium-ion battery.

[0010] A development known from the prior art involves the use of sulfur dioxide (SO2)-based electrolytes in rechargeable battery cells instead of organic electrolytes. Rechargeable battery cells containing SO2-based electrolytes have a particularly high ionic conductivity. The term "SO2-based electrolyte" in the sense of the present invention is understood to mean an electrolyte which not only contains SO2 in low concentrations as an additive, but in which the ionic mobility of the conductive salt contained in the electrolyte and which carries out the charge transport is ensured at least partially, mostly or completely by SO2. SO2 thus serves as a solvent for said conductive salt. Said conductive salt is often lithium tetrachloroaluminate (LiAlCl4), which forms a liquid solvate complex with gaseous SO2, in which SO2 is bound and which significantly reduces the vapor pressure compared to pure SO2. An electrolyte with a lower vapor pressure is produced. This type of SO2-based electrolyte has the advantage over the aforementioned organic electrolytes that it is non-flammable. It is thus possible to eliminate safety risks resulting from the flammability of the electrolyte.

[0011] For example, European Patent Specification No. 2534725 (hereinafter referred to as [V3]) discloses a rechargeable battery cell having a SO2-based electrolyte containing preferably a tetrahaloaluminate, particularly LiAlCl4, as a conductive salt.

[0012] With regard to the conductive elements, [V3] states that "nickel or a nickel alloy is often used to conductor the current to and from the electrodes...." The document further states that nickel foam is commonly used as the conductor means for the electrodes.

[0013] US Patent Application Publication No. 2004 / 0157129 (hereinafter referred to as [V4]) also shows a rechargeable battery cell with an SO2-based electrolyte. The inventors of [V4] discovered that undesired reactions occur between conductor elements and SO2-based electrolytes, especially conductive salts containing chlorides, such as LiAlCl4. This problem occurs especially in the case of battery cells that reach very high cell voltages (more than 4 volts) during charging. The problem is solved by a battery cell in which the conductive conductor element of at least one electrode contains, in a surface layer, an alloy of chromium and another metal and / or a protective metal as a reaction protection material that protects the conductor element from undesired reactions.

[0014] EP 2534719 B1 (hereinafter referred to as [V5]) also discloses an SO2-based electrolyte containing, inter alia, LiAlCl4 as a conductive salt. The LiAlCl4 forms a complex with SO2, for example with the formula LiAlCl4*1.5 mol SO2 or LiAlCl4*6 mol SO2. In [V5], lithium iron phosphate (LiFePO4) is used as the positive electrode. LiFePO4 has a lower end-of-charge voltage (3.7 V) compared to LiCoO2 (4.2 V). In the rechargeable battery cell, the problem of unintended reactions of the conductor elements does not occur, since the upper potential of 4.1 volts is not reached.

[0015] A further problem with SO2-based electrolytes is that many conductive salts, especially those known in organic lithium-ion batteries, are insoluble in SO2.

[0016] [Table 2]

[0017] Measurements have shown that SO2 is a poor solvent for many conductive salts, such as, for example: lithium fluoride (LiF), lithium bromide (LiBr), lithium sulfate (Li2SO4), lithium bis(oxalato)borate (LiBOB), lithium hexafluoroarsenate (LiAsF6), lithium tetrafluoroborate (LiBF4), lithium trilithium hexafluoroaluminate (Li3AlF6), lithium hexafluoroantimonate (LiSbF6), lithium difluoro(oxalato)borate (LiBF2C2O4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSL), lithium metaborate (LiBO2), lithium aluminate (LiAlO2), lithium triflate (LiCF3SO3) and lithium chlorosulfonate (LiSO3Cl). The solubility of the conductive salts in SO2 is about 10 -2 From 10 -4 mol / L (see Table 2). It can be assumed that at these low salt concentrations, there is at best low conductivity, insufficient for useful operation of a rechargeable battery cell. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] Patent No. 4306858 [Patent Document 2] JP 2001-143750 A [Patent Document 3] European Patent No. 2534725 [Patent Document 4] US Patent Application Publication No. 2004 / 0157129 [Patent Document 5] European Patent No. 2534719 Summary of the Invention [Problem to be solved by the invention]

[0019] In order to further improve the application and properties of rechargeable battery cells containing an SO2-based electrolyte, the present invention is based on the task of proposing a rechargeable battery cell with an SO2-based electrolyte, which, compared to rechargeable battery cells known from the prior art, is such that: - has electrodes with inert conductor elements that do not react with SO2-based electrolytes and are stable even at higher charging potentials; - It has electrodes with conductive elements that do not dissolve at higher potentials or promote oxidative electrolyte decomposition, and must not inhibit the reaction that creates the surface layer. - It has a wide electrochemical window so that oxidative electrolyte decomposition does not occur at the positive electrode, - have a stable surface layer on the negative electrode, where the surface capacity should be low and no further reductive electrolytic decomposition of the negative electrode occurs during subsequent operation; - has a SO2-based electrolyte with good solubility of conductive salts, which is a good ionic conductor and electronic insulator, thus facilitating ionic transport and minimizing self-discharge; - includes an SO2-based electrolyte that is inert to other components in a rechargeable battery cell, such as the separator, electrode materials, and cell housing materials; - Robust against electrical, mechanical or thermal abuse; - includes an SO2-based electrolyte that has higher stability against residual water in cell components in rechargeable battery cells; - Improved electrical performance data, in particular high energy density, - Improved overcharge and deep discharge properties as well as lower self-discharge properties; - Longer service life, especially with a higher number of available charge / discharge cycles, and - Be as cheap and highly available as possible, which is particularly important for large batteries or batteries that are widely distributed.

[0020] Rechargeable battery cells of this kind should have in particular very good electrical energy and performance data, high operational stability and service life, in particular a high number of available charge / discharge cycles, while ensuring that the electrolyte is not decomposed during operation of the rechargeable battery cell. [Means for solving the problem]

[0021] This problem is solved by a rechargeable battery cell having the features of claim 1. Claims 2 to 27 describe advantageous developments of the rechargeable battery cell according to the invention.

[0022] The rechargeable battery cell according to the invention comprises an active metal, at least one positive electrode having a conductor element, at least one negative electrode having a conductor element, a housing and an electrolyte. The conductor element of the positive electrode and the conductor element of the negative electrode are made independently of each other of a material selected from the group formed by aluminum and copper. The electrolyte is based on SO2 and contains at least one first conductive salt. The first conductive salt has the formula (I):

[0023] [ka]

[0024] In the formula (I), M is a metal selected from the group formed by alkali metals, alkaline earth metals, metals of group 12 of the periodic table, and aluminum. x is an integer from 1 to 3. The substituent R 1 , R 2 , R 3 and R 4 are C1 to C 10 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C3-C 10 Cycloalkyl, C6-C14 Aryl and C5-C 14 Heteroaryl is selected from the group formed by the central atom Z, which is aluminum or boron.

[0025] The term "conductor element" in the sense of the present invention refers to an electronically conductive element used to enable the required electronically conductive connection of the active material of the respective electrode to an external circuit, said respective conductor element being in electronically conductive contact with the active material participating in the electrode reaction of said respective electrode.

[0026] The SO2-based electrolyte used in the rechargeable battery cell according to the invention does not only contain SO2 as an additive in low concentrations, but also in such a concentration that the ionic mobility of the first conductive salt contained in the electrolyte and responsible for the charge transport is at least partially, mostly or completely ensured by SO2. The first conductive salt is dissolved in the electrolyte and has very good solubility in the electrolyte. The conductive salt can form a liquid solvate complex with gaseous SO2, in which SO2 is bound. In this case, the vapor pressure of the liquid solvate complex is significantly reduced compared to pure SO2, resulting in an electrolyte with a lower vapor pressure. However, it is also within the scope of the invention that no vapor pressure reduction may occur during the preparation of the electrolyte according to the invention, depending on the chemical structure of the first conductive salt according to formula (I). In the latter case, it is preferable to work at low temperature or under pressure during the preparation of the electrolyte according to the invention. The electrolyte may also contain several conductive salts according to formula (I), whose chemical structures differ from each other.

[0027] In the sense of the present invention, "C1-C 10The term "alkyl" comprises linear or branched saturated hydrocarbon groups having from 1 to 10 carbon atoms, including, in particular, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, 2,2-dimethylpropyl, n-hexyl, isohexyl, 2-ethylhexyl, n-heptyl, isoheptyl, n-octyl, isooctyl, n-nonyl, n-decyl, and the like.

[0028] In the sense of the present invention, "C2-C 10 The term "alkenyl" comprises unsaturated linear or branched hydrocarbon radicals having 2 to 10 carbon atoms, said hydrocarbon radical having at least one C-C double bond, including, in particular, ethenyl, 1-propenyl, 2-propenyl, 1-n-butenyl, 2-n-butenyl, isobutenyl, 1-pentenyl, 1-hexenyl, 1-heptenyl, 1-octenyl, 1-nonenyl, 1-decenyl, and the like.

[0029] In the sense of the present invention, "C2-C 10 The term "alkynyl" comprises unsaturated linear or branched hydrocarbon radicals having from 2 to 10 carbon atoms, said hydrocarbon radical having at least one C-C triple bond, including, in particular, ethynyl, 1-propynyl, 2-propynyl, 1-n-butynyl, 2-n-butynyl, isobutynyl, 1-pentynyl, 1-hexynyl, 1-heptynyl, 1-octynyl, 1-nonynyl, 1-decynyl, and the like.

[0030] In the sense of the present invention, "C3-C 10 The term "cycloalkyl" comprises cyclic saturated hydrocarbon groups having from 3 to 10 carbon atoms, including in particular cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclohexyl, cyclononyl and cyclodecanyl.

[0031] In the sense of the present invention, "C6-C 14The term "aryl" comprises aromatic hydrocarbon groups having 6 to 14 cyclic carbon atoms. This includes, in particular, phenyl (CH), naphthyl (CH), ... 10 H7 group) and anthracyl (C 14 H9 group) is applicable.

[0032] In the sense of the present invention, "C5-C 14 The term "heteroaryl" comprises aromatic hydrocarbon groups having 5 to 14 cyclic hydrocarbon atoms, at least one of which is substituted or replaced by a nitrogen, oxygen or sulfur atom. This applies in particular to pyrrolyl, furanyl, thiophenyl, pyridinyl, pyranyl, thiopyranyl, etc. All of the aforementioned hydrocarbon groups are bonded to the central atom according to formula (I) via the respective oxygen atom.

[0033] A rechargeable battery cell with this type of electrolyte has the advantage over rechargeable battery cells with electrolytes known from the prior art that the first conductive salt contained in the electrolyte has a higher oxidation stability, so that there is substantially no decomposition at higher cell voltages. The electrolyte preferably exhibits oxidation stability up to an upper potential of at least 4.0 volts, more preferably up to an upper potential of at least 4.2 volts, more preferably up to an upper potential of at least 4.4 volts, more preferably up to an upper potential of at least 4.6 volts, more preferably up to an upper potential of at least 4.8 volts and particularly preferably up to an upper potential of at least 5.0 volts. Thus, when such an electrolyte is used in a rechargeable battery cell, there is no or very little electrolyte decomposition within the working potential, i.e., in the range between the end-of-charge voltage and the end-of-discharge voltage of both electrodes of the rechargeable battery cell. Thus, the rechargeable battery cell according to the present invention can have an end-of-charge voltage of at least 4.0 volts, more preferably 4.4 volts, more preferably at least 4.8 volts, more preferably at least 5.2 volts, more preferably at least 5.6 volts and particularly preferably at least 6.0 volts. The service life of a rechargeable battery cell containing this electrolyte is significantly increased compared to rechargeable battery cells containing electrolytes known from the prior art.

[0034] Furthermore, rechargeable battery cells containing such electrolytes have low temperature stability. For example, 61% of the charged capacity can still be discharged at a temperature of -40°C. The conductivity of the electrolyte at low temperatures is sufficient to operate the battery cell. Furthermore, rechargeable battery cells containing such electrolytes have improved stability against residual water. In the case of traces of water remaining in the electrolyte (in the ppm range), the electrolyte or the first conductive salt together with the water form hydrolysis products that are significantly less corrosive to cell components than the SO2-based electrolytes known from the prior art. The absence of water in the electrolyte thus plays a less important role than the SO2-based electrolytes known from the prior art. The advantages of the electrolyte according to the invention outweigh the disadvantages resulting from the significantly larger anion size of the first conductive salt according to formula (I) compared to the conductive salts known from the prior art. The larger anion size leads to a lower conductivity of the first conductive salt according to formula (I) compared to the conductivity of LiAlCl4.

[0035] Positive and negative conductor elements In the following, advantageous developments of the rechargeable battery cell according to the invention will be explained with regard to the conductor elements of the positive pole and the conductor elements of the negative pole.

[0036] According to the invention, not only the positive electrode but also the negative electrode has a conductor element, which is used to enable the required electronically conductive connection of the active material of the respective electrode to an external circuit. For this purpose, the conductor element is in contact with the active material participating in the electrical reaction of the respective electrode. As mentioned above, according to the invention, the conductor element of the positive electrode and the conductor element of the negative electrode are formed independently from one another from a material selected from the group formed by aluminum and copper. In a preferred embodiment of the rechargeable battery cell according to the invention, the conductor element of the positive electrode consists of aluminum. In another preferred embodiment of the rechargeable battery cell according to the invention, the conductor element of the negative electrode is formed from copper. The conductor element of the positive electrode and / or the conductor element of the negative electrode can be formed as one piece or as several pieces.

[0037] The conductor elements of the positive electrode and / or the conductor elements of the negative electrode may be formed planar in the form of a thin metal sheet or a thin metal foil. The thin metal foil or thin metal foil may have a perforated or mesh structure. The planar conductor elements may also be formed by a metal-coated plastic foil. The metal coating preferably has a thickness in the range of 0.1 μm to 20 μm. The active material of the respective electrode is preferably applied to the surface of the thin metal sheet, the thin metal foil or the metal-coated plastic foil. The active material may be applied to the front and / or rear surface of the planar conductor elements. Planar conductor elements of this type preferably have a thickness in the range of 0.5 μm to 50 μm, particularly preferably in the range of 1 μm to 20 μm. When planar conductor elements are used, the total thickness of the respective electrodes may be at least 20 μm, preferably at least 40 μm and particularly preferably at least 60 μm. The maximum thickness is preferably at most 300 μm, preferably at most 150 μm and particularly preferably at most 100 μm.

[0038] The positive and / or negative electrodes with respect to a coating on one side of each of the conductor elements The area specific capacity of the negative electrode is preferably at least 0.5 mAh / cm when a planar conductor element is used. 2 and furthermore the following values ​​in this order are preferred: 1 mAh / cm 2 , 3mAh / cm 2 , 5mAh / cm 2 , 10mAh / cm 2 , 15mAh / cm 2 , 20mAh / cm 2 .

[0039] When the conductor element is formed planar in the form of a thin metal sheet, a thin metal foil or a metal-coated plastic foil, the amount of active material of the negative or positive electrode, i.e. the loading of the electrode in terms of coating on the one side, is preferably at least 1 mg / cm 2 , preferably at least 3 mg / cm 2 , and more preferably at least 5 mg / cm 2 , and more preferably at least 8 mg / cm 2 , and more preferably at least 10 mg / cm 2 and particularly preferably at least 20 mg / cm 2 It is.

[0040] The maximum loading of the electrode with respect to the coating on said one face is preferably at most 150 mg / cm 2 , and more preferably at most 100 mg / cm 2 and particularly preferably at most 80 mg / cm 2 It is.

[0041] It is also possible to form the conductor elements of the positive electrode and / or the conductor elements of the negative electrode in the form of a three-dimensional porous metal structure, in particular in the form of a metal foam. The three-dimensional porous metal structure is porous so that the active material of the respective electrode can be incorporated into the pores of the metal structure. The amount of the active material incorporated or applied refers to the filling of the electrode. When the conductor elements are formed in the form of a three-dimensional porous metal structure, in particular in the form of a metal foam, the respective electrode preferably has a thickness of at least 0.2 mm, preferably at least 0.3 mm, more preferably at least 0.4 mm, more preferably at least 0.5 mm and particularly preferably at least 0.6 mm.

[0042] In another advantageous embodiment of the rechargeable battery cell according to the invention, the area-specific capacity of the positive electrode and / or the negative electrode, in particular when using three-dimensional conductor elements in the form of metal foam, is preferably at least 2.5 mAh / cm 2 and the following values ​​are more preferred in this order: 2 , 15mAh / cm 2 , 25mAh / cm 2 , 35mAh / cm 2 , 45mAh / cm 2 , 55mAh / cm 2 , 65mAh / cm 2 , 75mAh / cm 2 When the conductor elements are formed in the form of a three-dimensionally porous metal structure, in particular in the form of a metal foam, the amount of active material of the positive electrode or the negative electrode, i.e. the filling of the respective electrode with respect to its surface, is at least 10 mg / cm. 2 , preferably at least 20 mg / cm 2 , and more preferably at least 40 mg / cm 2 , and more preferably at least 60 mg / cm 2 , and more preferably at least 80 mg / cm 2 and particularly preferably at least 100 mg / cm 2 This filling of the respective electrodes has a positive effect not only on the charging process but also on the discharging process of the rechargeable battery cell. Furthermore, the rechargeable battery cell can comprise at least one positive electrode having a conductor element in the form of a porous metal structure, in particular in the form of a metal foam, and at least one negative electrode having a planar conductor element in the form of a thin metal sheet, a thin metal foil or a metal-coated plastic foil. Alternatively, the rechargeable battery cell can comprise at least one negative electrode having a conductor element in the form of a porous metal structure, in particular in the form of a metal foam, and at least one positive electrode having a planar conductor element in the form of a thin metal sheet, a thin metal foil or a metal-coated plastic foil.

[0043] The active material of the positive electrode can at least partially or completely cover the conductor element. Furthermore, the active material of the negative electrode can at least partially or completely cover the conductor element. The planar conductor element as well as the three-dimensional conductor element can be formed as a multi-part mold. For contacting the conductor elements, the rechargeable battery cell can have further components, e.g. lugs, wires, sheets, etc., attached to the respective conductor elements. Said components can be formed using the same material as the respective conductor elements, i.e. aluminum or copper, but also other materials.

[0044] electrolyte In the following, advantageous developments of the rechargeable battery cell according to the invention will be explained with respect to an SO2-based electrolyte.

[0045] As described above, the substituent R in the formula (I) of the first conductive salt 1 , R 2 , R 3 and R 4 are C1 to C 10 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C3-C 10 Cycloalkyl, C6-C 14 Aryl and C5-C 14 In another advantageous embodiment of the rechargeable battery cell, the substituent R of the first conductive salt is selected from the group formed by 1 , R 2 , R 3 and R 4 are independently selected from the group formed by: - C1-C6 alkyl, preferably C2-C4 alkyl, particularly preferably 2-propyl, methyl and ethyl alkyl groups; alkenyl radicals from C2 to C6 alkenyl, preferably C2 to C4 alkenyl, particularly preferably ethenyl and propenyl, - C2-C6 alkynyl, preferably C2-C4 alkynyl, - C3-C6 cycloalkyl, - Phenyl, and - C5-C7 heteroaryl.

[0046] In this advantageous embodiment of the SO2-based electrolyte, the term "C1-C6 alkyl" comprises linear or branched saturated hydrocarbon groups having 1 to 6 hydrocarbon groups, in particular methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, 2,2-dimethylpropyl, n-hexyl and isohexyl. Of these, C2-C4 alkyl is preferred. Particularly preferred are the C2-C4 alkyls 2-propyl, methyl and ethyl.

[0047] In this advantageous embodiment of the SO2-based electrolyte, the term "C2-C6 alkenyl" comprises an unsaturated linear or branched hydrocarbon group having 2 to 6 carbon atoms, said hydrocarbon group having at least one C-C double bond. This applies in particular to ethenyl, 1-propenyl, 2-propenyl, 1-n-butenyl, 2-n-butenyl, isobutenyl, 1-pentenyl, 1-hexenyl, with C2-C4 alkenyl being preferred. Particularly preferred are ethenyl and 1-propenyl.

[0048] In this advantageous embodiment of the SO2-based electrolyte, the term "C2-C6 alkynyl" comprises an unsaturated linear or branched hydrocarbon group having 2 to 6 carbon atoms, said hydrocarbon group having at least one C-C triple bond. This applies in particular to ethynyl, 1-propynyl, 2-propynyl, 1-n-butynyl, 2-n-butynyl, isobutynyl, 1-pentynyl, 1-hexynyl. Of these, C2-C4 alkynyl is preferred.

[0049] In this advantageous embodiment of the SO2-based electrolyte, the term "C3-C6 cycloalkyl" comprises cyclic saturated hydrocarbon groups having 3 to 6 carbon atoms, including in particular cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

[0050] In this advantageous embodiment of the SO2-based electrolyte, the term "C5-C7 heteroaryl" comprises phenyl and naphthyl.

[0051] In another preferred embodiment of the rechargeable battery cell according to the invention, the substituent R 1 , R 2 , R 3 and R 4 At least two of the above are bridged to each other to form a bidentate chelating ligand. Such a bidentate chelating ligand may, for example, have the following structure:

[0052] [ka]

[0053] The substituent R 1 , R 2 , R 3 and R 4 It is also preferred that three or four of the ligands may be bridged to each other to form tridentate or tetradentate chelating ligands. The chelating ligands are coordinated to a central atom Z after formation of the chelate complex. The term "chelate complex" - or simply chelate - refers to a complex compound in which a multidentate ligand (having more than one free electron pair) occupies at least two coordination sites (binding sites) of the central atom. The central atom is a positively charged metal ion Al 3+ Or B 3+ The ligand and the central atom are bonded by a coordinate bond, which means that the bonding electron pair is composed only of the ligand.

[0054] Another preferred development of the rechargeable battery cell according to the invention has a cell voltage of at least 4.0 volts, preferably at least 4.4 volts, more preferably at least 4.8 volts, more preferably at least 5.2 volts, more preferably at least 5.6 volts and particularly preferably at least 6.0 volts.

[0055] In another preferred embodiment of the rechargeable battery cell according to the present invention, in order to improve the solubility of the first conductive salt in the SO2-based electrolyte, the substituent R 1 , R 2 , R 3 and R 4 is substituted with at least one fluorine atom and / or at least one chemical group, said chemical group being selected from the group formed by C1-C4 alkyl, C2-C4 alkenyl, C2-C4 alkynyl, phenyl and benzyl. Said chemical groups C1-C4 alkyl, C2-C4 alkenyl, C2-C4 alkynyl, phenyl and benzyl have similar properties or chemical structures as the aforementioned hydrocarbon groups. Substitution in this context means that the substituent R 1 , R 2 , R 3 and R 4 is substituted by said fluorine atoms and / or said chemical groups.

[0056] The substituent R 1 , R 2 , R 3 and R 4 When at least one of the groups is a CF3 group or an OSO2CF3 group, it is possible to obtain extremely high solubility of the first conductive salt in the SO2-based electrolyte.

[0057] In another advantageous development of the rechargeable battery cell, the first conductive salt is selected from the group formed by:

[0058] [ka]

[0059] The last-mentioned first conductive salt having the molecular formula LiB(O2C2(CF3)4)2 has two bidentate chelating ligands having the following structure, which, after formation of the chelate complex, are bonded to the central atom B 3+ Therefore, each of the two perfluoroalkoxy substituents is bridged to each other via a single C—C bond.

[0060] [ka]

[0061] In another preferred embodiment of the rechargeable battery cell according to the invention, in order to adapt the conductivity and / or further properties of the electrolyte to the desired values, the electrolyte comprises at least one second conductivity salt different from the first conductivity salt according to formula (I), which means that the electrolyte may comprise in addition to the first conductivity salt one or more second conductivity salts which differ from the first conductivity salt not only in their chemical composition but also in their chemical structure.

[0062] In another preferred embodiment of the rechargeable battery cell according to the invention, the second conductive salt is an alkali metal compound, in particular a lithium compound, the alkali metal compound or the lithium compound being selected from the group formed by aluminates, halides, oxalates, borates, phosphates, arsenates and gallates, the second conductive salt is preferably a lithium tetrahaloaluminate, in particular LiAlCl4.

[0063] In yet another preferred embodiment of the rechargeable battery cell according to the invention, the electrolyte comprises at least one additive, which may be vinylene carbonate and its derivatives, vinyl ethylene carbonate and its derivatives, methyl ethylene carbonate and its derivatives, lithium (bisoxalato)borate, lithium difluoro(oxalato)borate, lithium tetrafluoro(oxalato)phosphate, lithium oxalate, 2-vinylpyridine, 4-vinylpyridine, cyclic exomethylene carbonate, sulfones, cyclic and acyclic sulfonates, acyclic sulfites, cyclic and acyclic sulfinic acid esters, organic esters of inorganic acids, acyclic and cyclic alkanes (such acyclic and and cyclic alkanes having a boiling point of at least 36° C. at 1 bar), aromatic compounds, halogenated cyclic and acyclic sulfonylimides, halogenated cyclic and acyclic phosphates, halogenated cyclic and acyclic phosphines, halogenated cyclic and acyclic phosphites, halogenated cyclic and acyclic phosphazenes, halogenated cyclic and acyclic silylamines, halogenated cyclic and acyclic halogenated esters, halogenated cyclic and acyclic amides, halogenated cyclic and acyclic anhydrides and halogenated organic heterocycles.

[0064] In another preferred embodiment of the rechargeable battery cell according to the invention, the electrolyte has the following composition, relative to the total weight of the electrolyte composition: (i) 5 to 99.4 wt. % sulfur dioxide; (ii) 0.6 to 95 wt % of the first conductive salt; (iii) 0 to 25 wt % of said second conductive salt, and (iv) 0 to 10 wt % of said additive.

[0065] As mentioned above, the electrolyte can contain not only one first conductive salt and one second conductive salt according to formula (I) but also multiple first conductive salts and multiple second conductive salts, respectively, according to formula (I). In the latter case, the above-mentioned ratio includes multiple first conductive salts and multiple second conductive salts. The substance concentration of the first conductive salt is in the range of 0.01 mol / l to 10 mol / l, preferably 0.05 mol / l to 10 mol / l, more preferably 0.1 mol / l to 6 mol / l and particularly preferably 0.2 mol / l to 3.5 mol / l with respect to the total volume of the electrolyte.

[0066] In another preferred development of the rechargeable battery cell according to the invention, the electrolyte comprises at least 0.1 mol SO2 per mole of conductive salt, preferably at least 1 mol SO2, more preferably at least 5 mol SO2, more preferably at least 10 mol SO2 and particularly preferably at least 20 mol SO2. The electrolyte can also comprise a very high molar ratio of SO2, with a preferred upper limit of 2600 mol SO2 per mole of conductive salt, with upper limits of 1500, 1000, 500 and 100 mol SO2 per mole of conductive salt being preferred in that order. The term "per mole of conductive salt" refers to all conductive salts contained in the electrolyte. SO2-based electrolytes with this type of concentration ratio between SO2 and the conductive salt have the advantage that they are capable of dissolving a larger amount of conductive salt than electrolytes known from the prior art, for example based on organic solvent mixtures. Surprisingly, within the scope of the present invention, an electrolyte having a relatively small conductive salt concentration has been found to be advantageous, in spite of the associated increase in vapor pressure, particularly with regard to its stability over multiple charge / discharge cycles of the rechargeable battery cell. The SO2 concentration in the electrolyte affects the conductivity of the electrolyte. Thus, by selecting the SO2 concentration, the conductivity of the electrolyte can be adapted to the intended use of the rechargeable battery cell operated by the electrolyte. The total weight of SO2 and the first conductive salt can be more than 50 weight percent (wt%) of the weight of the electrolyte, preferably more than 60 wt%, more preferably more than 70 wt%, more preferably more than 80 wt%, more preferably more than 85 wt%, more preferably more than 90 wt%, more preferably more than 95 wt% or even more preferably more than 99 wt%.

[0067] The electrolyte may contain at least 5 wt% SO2 with respect to the total amount of electrolyte contained in the rechargeable battery cell, with more preferred values ​​being 20 wt% SO2, 40 wt% SO2 and 60 wt% SO2. The electrolyte may contain up to 95 wt% SO2, with maximum values ​​of 80 wt% SO2 and 90 wt% SO2 being preferred in that order.

[0068] It is also within the scope of the present invention that the proportion of at least one organic solvent in the electrolyte is low or absent. The proportion of organic solvent in the electrolyte, for example in the form of a solvent or a mixture of organic solvents, may be at most 50 wt% of the weight of the electrolyte. Particularly preferred are smaller proportions, such as at most 40 wt%, at most 30 wt%, at most 20 wt%, at most 15 wt%, at most 10 wt%, at most 5 wt% or at most 1 wt% of the weight of the electrolyte. It is further preferred that the electrolyte is free of organic solvents. With a low or no proportion of organic solvents, the electrolyte has little or no flammability. This improves the operational safety of rechargeable battery cells operated with this type of SO2-based electrolyte. It is particularly preferred that the SO2-based electrolyte is substantially free of organic solvents.

[0069] In another advantageous development of the rechargeable battery cell, the electrolyte has the following composition, relative to the total weight of the electrolyte composition: (i) 5 to 99.4 wt. % sulfur dioxide; (ii) 0.6 to 95 wt % of the first conductive salt; (iii) 0 to 25 wt % of said second conductive salt; (iv) 0 to 10 wt % of said additive, and (v) 0 to 50 wt % organic solvent.

[0070] active metal Advantageous developments of the rechargeable battery cell according to the invention with respect to the active metals are described below:

[0071] In an advantageous development of the rechargeable battery cell, the active metal is: - an alkali metal, in particular lithium or sodium, - alkaline earth metals, especially calcium, - metals of group 12 of the periodic table, in particular zinc, or - Aluminum.

[0072] positive electrode Advantageous developments of the rechargeable battery cell according to the invention with respect to the positive electrode are described below:

[0073] In a first development of the rechargeable battery cell according to the invention, the positive electrode is chargeable to an upper potential of at least 4.0 volts, preferably up to a potential of 4.4 volts, further preferably up to a potential of at least 4.8 volts, further preferably up to a potential of at least 5.2 volts, further preferably up to a potential of at least 5.6 volts and particularly preferably up to a potential of at least 6.0 volts.

[0074] In another advantageous development of the rechargeable battery cell according to the invention, the positive electrode comprises at least one active material capable of storing ions of the active metal and releasing and reaccepting said ions of the active metal during operation of the battery cell.

[0075] In another advantageous development of the rechargeable battery cell according to the invention, the positive electrode comprises at least one intercalation compound. The term "intercalation compound" in the sense of the present invention is to be understood as a subcategory of the aforementioned intercalation materials. The intercalation compound acts as a host matrix with interconnected voids into which the ions of the active metal can diffuse and accumulate during the discharge process of the rechargeable battery cell. Little or no structural changes of the host matrix occur in the course of the accumulation of the ions of the active metal.

[0076] In another advantageous development of the rechargeable battery cell according to the invention, the positive electrode comprises at least one conversion compound as the active material. The term "conversion compound" in the sense of the present invention is to be understood as a material which forms other materials during electrochemical activity, i.e. chemical bonds are broken and reformed during charging and discharging of the battery cell. Upon acceptance and release of the ions of the active metal, structural changes occur in the matrix of the conversion compound.

[0077] In another advantageous development of the rechargeable battery cell according to the invention, the active material is x M' y M” z O a The composition A has the following composition. x M' y M” z O a In A is at least one metal selected from the group formed by alkali metals, alkaline earth metals, metals of group 12 of the periodic table of the elements or aluminium, M' is at least one metal selected from the group formed by the elements Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn, M″ is at least one element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the Periodic Table of the Elements, - x and y are independent numbers greater than 0, - z is a number equal to or greater than 0, and - a is a number greater than 0.

[0078] Preferably, A is metallic lithium, i.e. the compound is Li x M' y M” z O a The composition may be:

[0079] Composition A x M' y M” zO a The indices y and z in the formula represent the sum of the metal and element represented by M' or M'', respectively. For example, M' is the sum of two metals M' 1 and M' 2 In the case where the compound comprises a metal M', the index y is y=y1+y2, and y1 and y2 are each independently selected from the group consisting of a metal M' 1 and M' 2 The indices x, y, z and a must be selected so that the charge in the composition is neutral. An example of a compound where M' contains two metals is M' 1 =Ni,M' 2 = Mn and M″ = Co x Ni y1 Mn y2 Co z An example of a compound where z=0, i.e., there is no other metal or element M″, is lithium cobalt oxide Li x Co y O a For example, M" has two elements, one is metal M" 1 And on the other hand, M” 2 When the compound contains phosphorus as the metal M", for the index z, z=z1+z2, and z1 and z2 are each independently selected from the group consisting of the metal M" 1 and Lin (M 2 The indices x, y, z and a must be selected so that the charge in the composition is neutral. A represents lithium, M″ represents the metal M″ 1 and M.” 2 Examples of compounds containing phosphorus as A are A=Li, M'=Fe, M" 1 =Mn, M” 2 Lithium iron manganese phosphate Li = P and z2 = 1 x Fe y Mn z1 P z2 O4. In other compositions, M" is two nonmetallic compounds, e.g. M" 1 Fluorine as M” 2 An example of such a compound is lithium iron fluorosulfate Li, where A=Li, M'=Fe, M"1=F, and M"2=P. x Fe yF z1 S z2 There is O4.

[0080] In another advantageous development of the rechargeable battery cell according to the invention, M' consists of the metals nickel and manganese and M" is cobalt. In this case, the metals of the formula Li x Ni y1 Mn y2 Co z Lithium with the composition O2(NMC), i.e., layered oxide structure D Kuckel Ma Ngan Ko Examples of the active material made of such lithium nickel manganese cobalt oxide include LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O2(NMC111), LiNi 0.6 Mn 0.2 Co 0.2 O2(NMC622) and LiNi 0.8 Mn 0.1 Co 0.1 O2 (NMC811). Other compounds made of lithium nickel manganese cobalt oxide have the composition LiNi 0.5 Mn 0.3 Co 0.2 O2, LiNi 0.5 Mn 0.25 Co 0.25 O2, LiNi 0.52 Mn 0.32 Co 0.16 O2, LiNi 0.55 Mn 0.30 Co 0.15 O2, LiNi 0.58 Mn 0.14 Co 0.28 O2, LiNi 0.64 Mn 0.18 Co 0.18 O2, LiNi 0.65 Mn 0.27 Co 0.08 O2, LiNi 0.7 Mn 0.2 Co 0.1 O2, LiNi 0.7 Mn 0.15 Co 0.15 O2, LiNi0.72 Mn 0.10 Co 0.18 O2, LiNi 0.76 Mn 0.14 Co 0.10 O2, LiNi 0.86 Mn 0.04 Co 0.10 O2, LiNi 0.90 Mn 0.05 Co 0.05 O2, LiNi 0.95 Mn 0.025 Co 0.025 O2, or a combination thereof. The compounds can be used to prepare positive electrodes for rechargeable battery cells having cell voltages greater than 4.6 volts.

[0081] In another advantageous development of the rechargeable battery cell according to the invention, the active material is a metal oxide rich in lithium and manganese (in English: lithium and manganese rich oxide material). The metal oxide has the composition Li x Mn y M” z O a Thus, M′ may have the above formula Li x M' y M” z O a Here, the index x is 1 or more, and the index y is greater than the index z or the sum of the indices z1+z2+z3, etc. For example, M″ is the sum of two metals M″ with indices z1 and z2. 1 and M.” 2 (e.g., M" 1 =Ni z1=0.175 and M” 2 =Co z2=0.1 Li 1.2 Mn 0.525 Ni 0.175 Co 0.1O2), for the exponent y, y > z1 + z2 holds. The exponent z is 0 or greater, and the exponent a is greater than 0. The exponents x, y, z, and a must be selected so that the charge within the composition is neutral. The lithium- and manganese-rich metal oxide can also be represented by the formula mLi2MnO3(1 - m)LiM’O2 where 0 < m < 1. An example of this type of compound is Li 1.2 Mn 0.525 Ni 0.175 CO 0.1 O2, Li 1.2 Mn 0.6 Ni 0.2 O2 or Li 1.2 Ni 0.13 CO 0.13 Mn 0.54 O2.

[0082] In another advantageous development aspect of the rechargeable battery cell according to the present invention, the composition has the formula A x M’ y M” z O4. The compound has a spinel structure. For example, A can be lithium, M’ can be cobalt, and M” can be manganese. In this case, the active material is lithium cobalt manganese oxide (LiCoMnO4). It is possible to manufacture a positive electrode for a rechargeable battery cell having a cell voltage greater than 4.6 volts using LiCoMnO4. The LiCoMnO4 preferably does not contain Mn 3+ . In another example, M’ can be nickel and M” can be manganese. In this case, the active material is lithium nickel manganese oxide (LiNiMnO4). The molar ratios of both metals M’ and M” may be different. Lithium nickel manganese oxide can have a composition such as LiNi 0.5 Mn 1.5 O4.

[0083] In another advantageous development of the rechargeable battery cell according to the invention, the positive electrode comprises at least one active material which is a conversion compound, which upon receiving an active metal, for example lithium or sodium, undergoes a solid-state redox reaction, during which the crystalline structure of the material changes. This occurs under the breaking and reformation of chemical bonds. A fully reversible reaction of the conversion compound can be, for example, as follows: Type A: MX z +yLi ⇔ M+zLi (y / z) X Type B: X+yLi ⇔ Li y X

[0084] Examples of conversion compounds are FeF2, FeF3, CoF2, CuF2, NiF2, BiF3, FeCl3, FeCl2, CoCl2, NiCl2, CuCl2, AgCl, LiCl, S, Li2S, Se, Li2Se, Te, I and Lil.

[0085] In another advantageous development, the compound is x M' y M” 1 z1 M” 2 z2 O4 composition, M” 1 is selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the Periodic Table of the Elements; M" 2 is the element phosphorus, x and y are each independently a number greater than 0, z1 is a number greater than 0, and z2 has a value of 1. x M' y M” z1 M” z2 Compounds with the formula Li x Fe' y Mn z1 P z2 Examples of lithium metal phosphates are lithium iron phosphate (LiFePO4) or lithium iron manganese phosphate (Li(Fe y Mn zAn example of lithium manganese ferrophosphate is Li(FePO4). 0.3 Mn 0.7 An example of lithium manganese phosphate is Li(Fe 0.3 Mn 0.7 Lithium metal phosphates having other compositions may also be used in the battery cells according to the present invention.

[0086] In another advantageous development of the rechargeable battery cell according to the invention, the positive electrode comprises at least one metal compound selected from the group formed by metal oxides, metal halides and metal phosphates, the metal of which is preferably a transition metal of atomic numbers 22 to 28 of the periodic table of the elements, in particular cobalt, nickel, manganese or iron.

[0087] In another advantageous development of the rechargeable battery cell according to the invention, the positive electrode comprises at least one metal compound having the chemical structure of a spinel, a layered oxide, a conversion compound or a polyanionic compound.

[0088] It is within the scope of the present invention that the positive electrode comprises at least one of the aforementioned compounds or combinations of compounds as active materials, by which is meant a positive electrode comprising at least two of the aforementioned materials.

[0089] In another advantageous development of the battery cell according to the invention, the positive electrode comprises at least one binder, which is a fluorinated binder, in particular polyvinylidene fluoride and / or a terpolymer formed by tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride. However, it may also be a binder consisting of a polymer consisting of monomeric structural units of conjugated carboxylic acids or of alkali metal, alkaline earth metal or ammonium salts of said conjugated carboxylic acids or a combination thereof. It may also be a polymer based on monomeric styrene and butadiene structural units. It may also be a binder consisting of a binder from the carboxymethylcellulose group. The binder is preferably present in the positive electrode in a concentration of at most 20 wt%, more preferably at most 15 wt%, more preferably at most 10 wt%, more preferably at most 7 wt%, more preferably at most 5 wt% and particularly preferably at most 2 wt%, based on the total weight of the positive electrode.

[0090] negative electrode Advantageous developments of the rechargeable battery cell according to the invention with respect to the negative electrode are described below:

[0091] In another advantageous development of the rechargeable battery cell, the negative electrode is an insertion electrode. The insertion electrode comprises an insertion material as active material, in which ions of the active metal are stored during charging of the rechargeable battery cell and can be released from the insertion material during discharging of the rechargeable battery cell. This means that electrode processes can be carried out not only on the surface of the negative electrode but also inside the negative electrode. For example, when using lithium-based conductive salts, lithium ions can be stored in the insertion material during charging of the rechargeable battery cell and can be released from the insertion material during discharging of the rechargeable battery cell. The negative electrode preferably comprises carbon, in particular modified graphite, as active or insertion material. However, it is also within the scope of the invention that the carbon is in the form of natural graphite (flaky promoter or round), synthetic graphite (mesophase graphite), graphitized mesocarbon microbeads (MCMB), carbon-coated graphite or amorphous carbon.

[0092] In another advantageous development of the rechargeable battery cell according to the invention, the negative electrode is, for example, lithium titanate (e.g. Li4Ti5O 12 ) or the like.

[0093] In another advantageous development of the rechargeable battery cell according to the invention, the negative electrode comprises an active negative electrode material which forms an alloy with lithium, for example metals and metal alloys which store lithium (e.g. Si, Ge, Sn, SnCo). x C y , SnSi x etc.) and oxides of metals and metal alloys that store lithium (e.g., SnO x , SiO x Or oxide glasses of Sn, Si, etc.

[0094] In another advantageous development of the rechargeable battery cell according to the invention, the negative electrode comprises a converted negative electrode active material, for example manganese oxide (MnO x ), iron oxide (FeO x ), cobalt oxide (CoOx ), nickel oxide (NiO x ), copper oxide (CuO x ), metal hydrides in the form of magnesium hydride (MgH2), titanium hydride (TiH2), aluminum hydride (AlH3), and ternary hydrides based on boron, aluminum, and magnesium.

[0095] In another advantageous development of the rechargeable battery cell according to the invention, the negative electrode comprises a metal, in particular metallic lithium.

[0096] In another advantageous development of the rechargeable battery cell according to the invention, the negative electrode is porous, with a porosity of preferably at most 50%, more preferably at most 45%, more preferably at most 40%, more preferably at most 35%, more preferably at most 30%, more preferably at most 20% and particularly preferably at most 10%. The porosity refers to the void volume relative to the total volume of the negative electrode, the void volume being formed by so-called pores or voids. The porosity results in an increase in the internal surface of the negative electrode. Furthermore, the porosity reduces the density of the negative electrode and thus also its weight. The individual pores of the negative electrode can be preferably completely filled by the electrolyte during operation.

[0097] In another advantageous development of the battery cell according to the invention, the negative electrode comprises at least one binder, which is a fluorinated binder, in particular polyvinylidene fluoride and / or a terpolymer formed by tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride. However, it may also be a binder consisting of a polymer consisting of monomeric structural units of conjugated carboxylic acids or of alkali metal, alkaline earth metal or ammonium salts of said conjugated carboxylic acids or a combination thereof. It may also be a polymer based on monomeric styrene and butadiene structural units. It may also be a binder consisting of a binder from the carboxymethylcellulose group. The binder is preferably present in the negative electrode in a concentration of at most 20 wt%, more preferably at most 15 wt%, more preferably at most 10 wt%, more preferably at most 7 wt%, more preferably at most 5 wt% and particularly preferably at most 2 wt%, relative to the total weight of the negative electrode.

[0098] In another advantageous development of the battery cell according to the invention, the negative electrode comprises at least one conductive additive, which preferably has a low weight, high chemical resistance and a high specific surface area. Examples of conductive additives are particulate carbon (carbon black, Super P, acetylene black), fibrous carbon (carbon nanotubes CNT, carbon (nano)fibers), finely divided graphite and graphene (nanosheets).

[0099] Rechargeable battery cell structure Advantageous developments of the rechargeable battery cell according to the invention are explained below with respect to its structure:

[0100] In order to further improve the function of the rechargeable battery cell, in another advantageous development of the rechargeable battery cell according to the invention, the rechargeable battery cell has a number of negative electrodes and a number of positive electrodes arranged in a housing in an alternating stack, the positive electrodes and the negative electrodes being preferably electrically separated from each other by respective separators.

[0101] However, the rechargeable battery cell may also be formed as a coil cell, in which the electrodes are formed as thin layers wound with a separator material. The separator, on the one hand, spatially and electrically separates the positive and negative electrodes, and on the other hand, is permeable, inter alia, to the ions of the active metal. This creates a large electrochemically effective surface, which allows a correspondingly high current yield. The separator can be formed using nonwovens, membranes, wovens, knits, organic materials, inorganic materials or combinations thereof. Organic separators can consist, for example, of unsubstituted polyolefins (e.g. polypropylene or polyethylene), partially to fully halogen-substituted polyolefins (e.g. partially to fully fluorinated, in particular PVDF, ETFE, PTFE), polyesters, polyamides or polysulfones. Separators comprising a combination of organic and inorganic materials are, for example, woven glass fiber materials, in which glass fibers are provided with a suitable polymer coating. The coating is a fluorine-containing polymer, such as polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), perfluoroethylene propylene (FEP), THV (a terpolymer of tetrafluoroethylene, hexafluoroethylene, and vinylidene fluoride), perfluoroalkoxy polymer (PFA), aminosilane, polypropylene, or polyethylene (PE). The separator can also be folded in the housing of the rechargeable battery cell, for example in a so-called "Z-fold" shape. In the case of the Z-fold, the strip-shaped separator is folded in a Z shape so as to pass through the electrodes or around the electrodes. The separator can also be formed as a separator paper.

[0102] It is also within the scope of the present invention that the separator may be formed as a coating, and the positive electrode or the negative electrode, respectively, may be covered by the coating. The coating may be formed using a nonwoven fabric, a membrane, a woven fabric, a knitted fabric, an organic material, an inorganic material, or a combination thereof.

[0103] The coating of the positive electrode allows for uniform ion migration and distribution in the rechargeable battery cell. The more uniform the ion distribution in the negative electrode, the greater the possible loading of active material in the negative electrode and, therefore, the greater the usable capacity of the rechargeable battery cell. At the same time, the risk of uneven loading and the resulting precipitation of the active metal is avoided. This advantage is particularly evident when the positive electrode of the rechargeable battery cell is covered by the coating.

[0104] The surface dimensions of the electrode and the coating are preferably coordinated with one another such that the outer dimensions of the coating of the electrode and the outer dimensions of the uncoated electrode match in at least one dimension.

[0105] The surface area of ​​the coating may preferably be larger than the surface area of ​​the electrode, in which case the coating extends beyond the boundaries of the electrode, so that two layers of the coating covering both sides of the electrode may be connected to each other at the edge of the positive electrode by an edge connection.

[0106] In a further advantageous embodiment of the rechargeable battery cell according to the invention, the negative electrode has a coating whereas the positive electrode has no coating.

[0107] Further advantageous properties of the present invention are described and explained in detail below with the aid of figures, examples and experiments. [Brief description of the drawings]

[0108] [Figure 1] 1 is a cross-sectional view of a first example embodiment of a rechargeable battery cell according to the present invention; [Diagram 2]FIG. 2 is a detailed view of an electron microscope photograph of the three-dimensional pore structure of the metal foam according to the first embodiment of FIG. 1. [Diagram 3] FIG. 2 is a cross-sectional view of a second example embodiment of a rechargeable battery cell according to the present invention. [Figure 4] FIG. 4 is a diagram showing details of the second embodiment of FIG. 3. [Diagram 5] FIG. 11 is an exploded view of a third example embodiment of a rechargeable battery cell according to the present invention. [Figure 6] FIG. 1 shows the potential (units [V]) during charging in two experimental complete cells having a graphite electrode with copper or nickel conductor elements filled with the reference electrolyte according to Example 1 as a function of capacity with respect to the theoretical capacity of the negative electrode when the surface layer is formed on the negative electrode. [Figure 7] FIG. 1 shows the discharge capacity as a function of cycle number for two experimental complete cells having graphite electrodes with copper or nickel conductor elements, the experimental complete cells being filled with the reference electrolyte. [Figure 8] FIG. 1 shows the potential (in [V]) in two experimental complete cells having a graphite electrode with copper or nickel conductor elements filled with electrolyte 1 during charging as a function of capacity relative to the theoretical capacity of the negative electrode during the formation of a surface layer on the negative electrode. [Figure 9] FIG. 1 shows the discharge capacity as a function of cycle number for two experimental complete cells having graphite electrodes with copper or nickel conductor elements, the experimental complete cells being filled with electrolyte 1. [Figure 10] 10 is a photograph showing the copper conductor element of FIG. 9 after measurement. [Figure 11] 1 shows the potential course (in volts) during charging and discharging as a function of the charge rate for a half-cell with a graphite electrode with copper conductor elements, the half-cell being filled with electrolyte 5. [Figure 12] FIG. 1 shows the potential and current as a function of time for half-cells with aluminum conductor elements filled with reference electrolyte or electrolyte 1. [Figure 13]FIG. 13 shows the aluminum conductor element in the half-cell with reference electrolyte of FIG. 12 before the experiment. [Figure 14] FIG. 13 shows the aluminum conductor element after the experiment in the half-cell with the reference electrolyte of FIG. 12. [Figure 15] FIG. 13 shows the aluminum conductor element after an experiment in a half-cell with electrolyte 1 of FIG. 12. [Figure 16] 1 shows the potential course (in volts) during charging and discharging as a function of the charge rate for the first cycle of a half-cell with a positive electrode having an aluminum conductor element. The half-cell is filled with electrolyte 1. [Figure 17] 1 shows the discharge capacity as a function of cycle number for an experimental complete cell with a positive electrode having an aluminum conductor element, the experimental complete cell being filled with electrolyte 1. [Figure 18] FIG. 1 shows the discharge capacity as a function of cycle number for two complete cells with a positive electrode having an aluminum conductor element and a negative electrode having a copper conductor element, the complete cells being filled with electrolyte 1 and having an end-of-charge voltage of 4.3 or 4.6 volts. [Figure 19] 1 shows the potential course (in volts) during charging and discharging as a function of the charge rate for the first cycle of a half-cell with a positive electrode having an aluminum conductor element, the half-cell being filled with electrolyte 5. [Figure 20] FIG. 1 shows the potential (in [V]) in three experimental complete cells filled with electrolytes 1 and 3 according to Example 2 and the reference electrolyte according to Example 1 during charging of the negative electrode as a function of capacity relative to the theoretical capacity of the negative electrode during the formation of a surface layer on the negative electrode. [Figure 21] FIG. 1 shows the potential course (in volts) during discharge as a function of the charge rate for four experimental complete cells filled with electrolytes 1, 3, 4 and 5 according to Example 2 and containing lithium nickel manganese cobalt oxide (NMC) as electrode active material. [Figure 22]FIG. 2 shows the conductivity (units [mS / cm]) of electrolytes 1, 4 and 6 according to Example 2 depending on the concentration of compounds 1, 4 and 6. [Diagram 23] FIG. 2 shows the conductivity (units [mS / cm]) of electrolytes 3 and 5 according to example 2 depending on the concentration of compounds 3 and 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0109] FIG. 1 shows a cross-sectional view of a first embodiment of a rechargeable battery cell 2 according to the invention. The rechargeable battery cell 2 is formed as a prismatic cell and has, inter alia, a housing 1. The housing 1 encloses an electrode unit 3, which comprises three positive electrodes 4 and four negative electrodes 5. The positive electrodes 4 and the negative electrodes 5 are arranged in an alternating stack in the electrode unit 3. However, the housing 1 can also accommodate more positive electrodes 4 and / or negative electrodes 5. In general, it is preferred that the number of negative electrodes 5 exceeds the number of positive electrodes 4 by one. The outer end face of the electrode stack is thus formed by the electrode surface of the negative electrode 5. The electrodes 4, 5 are connected via electrode connections 6, 7 to corresponding connection contacts 9, 10 of the rechargeable battery cell 2. The rechargeable battery cell 2 is filled with an SO2-based electrolyte, with the electrolyte penetrating as completely as possible into all pores or cavities of the electrodes 4, 5, in particular on the inside. The electrolyte is not shown in FIG. 1. In this embodiment, the positive electrode 4 comprises an intercalation compound as active material. The intercalation compound is LiCoMnO4 with a spinel structure. In this embodiment, the electrodes 4, 5 are formed as planar layers, i.e. layers with a small thickness in relation to their surface area. The electrodes are separated from each other by a separator 11. The housing 1 of the rechargeable battery cell 2 is formed in a substantially cubic shape, the electrodes 4, 5 and the walls of the housing 1, shown in cross section, extend perpendicular to the drawing plane and are formed substantially straight and flat. The rechargeable battery cell 2 may, however, also be formed as a coil cell, in which the electrodes are formed as thin layers wound with a separator material. The separator 11, on the one hand, spatially and electrically separates the positive electrode 4 and the negative electrode 5, and on the other hand, is permeable, inter alia, to the ions of the active metal. This forms a large electrochemically effective surface, which allows a correspondingly high current yield. Furthermore, the electrodes 4, 5 each have a conductor element that is used to enable the required electronically conductive connection of the active materials of the respective electrodes.The conductive element is in contact with the active material (not shown in FIG. 1) involved in the electrode reaction of each of the electrodes 4, 5. The conductive element is formed in the form of a porous metal foam 18. The metal foam 18 extends over the thickness dimension of the electrodes 4, 5. The active materials of the positive electrode 4 and the negative electrode 5 are respectively incorporated into the pores of the metal foam 18, so that the active materials uniformly fill the pores of the metal foam over the total thickness of the metal structure. To improve the mechanical strength, the positive electrode 4 contains a binder. The binder is a fluoropolymer. The negative electrode 5 contains carbon as the active material in a form suitable for receiving lithium ions as an intercalation material. The structure of the negative electrode 5 is similar to that of the positive electrode 4. In this first embodiment, the conductive element of the positive electrode 4 is made of aluminum and the conductive element of the negative electrode 5 is made of copper.

[0110] Figure 2 illustrates an electron micrograph of the three-dimensional pore structure of the metal foam 18 of the first example embodiment in Figure 1. Based on the scale shown, it can be seen that the average diameter of the pores P is greater than 100 μm, i.e., relatively large.

[0111] FIG. 3 shows a cross-sectional view of a second embodiment of a rechargeable battery cell 20 according to the invention. This second embodiment differs from the first embodiment shown in FIG. 1 in that the electrode unit comprises one positive electrode 23 and two negative electrodes 22. The electrodes are separated from each other by separators 21 and are surrounded by a housing 28. The positive electrode 23 comprises a conductor element 26 in the form of a planar metal foil on which the active material 24 of the positive electrode 23 is applied on both sides. The negative electrode 22 also comprises a second conductor element 27 in the form of a planar metal foil on which the active material 25 of the negative electrode 22 is applied on both sides. Alternatively, it is also possible to coat only one side of the planar conductor element of the edge electrode, i.e. the electrode that closes the electrode stack, with active material. The uncoated side faces the wall of the housing 28. The electrodes 22 , 23 are connected via electrode connections 29 , 30 to corresponding connection contacts 31 , 32 of the rechargeable battery cell 20 .

[0112] Figure 4 illustrates the planar metal foil used as the conductor elements 26, 27 of the positive electrode 23 and the negative electrode 22, respectively, in the second embodiment of Figure 3. The metal foil has a perforated or mesh-like structure with a thickness of 20 μm.

[0113] Fig. 5 shows an exploded view of a third embodiment of a rechargeable battery cell 40 according to the invention. This third embodiment differs from the previous two embodiments in that the positive electrode 44 is covered by a coating 13, the surface area of ​​which is greater than that of the positive electrode 44, the boundary 14 of which is drawn in Fig. 5 by a dashed line. The two layers 15, 16 of the coating 13, which cover both sides of the positive electrode 44, are connected to each other by an edge connection 17 at the periphery of the positive electrode 44. Both negative electrodes 45 are uncoated. The electrodes 44 and 45 can be contacted via the electrode connections 46 and 47.

[0114] [Example 1] Preparation of reference electrolyte The reference electrolyte used in the examples described below was prepared according to the method described in EP 2954588 (hereinafter referred to as [V6]). First, lithium chloride (LiCl) was dried under vacuum at 120°C for three days. Aluminum particles (Al) were dried under vacuum at 450°C for two days. LiCl, aluminum chloride (AlCl3) and Al were mixed together in a glass bottle with an opening for escaping gases so that the molar ratio of AlCl3:LiCl:Al was 1:1.06:0.35. The mixture was then heat-treated in stages to produce a molten salt. After cooling, the formed molten salt was filtered, then cooled to room temperature and finally SO2 was added until the desired molar ratio of SO2 to LiAlCl4 was formed. The reference electrolyte thus formed had the composition LiAlCl4*xSO2, where x depends on the amount of SO2 added.

[0115] Example 2: Preparation of six embodiments of SO2-based electrolytes for battery cells: Examples 1, 2, 3, 4, 5 and 6 Six examples of SO2-based electrolytes, 1, 2, 3, 4, 5 and 6, were prepared for the experiments described below (hereinafter referred to as electrolytes 1, 2, 3, 4, 5 and 6). For this purpose, five different first conductive salts according to formula (I) were first prepared according to the preparation methods described in the following documents [V7], [V8] and [V9]: [V7]I. Krossing, Chem. Eur. J. 2001, 7, 490 [V8]SM Ivanova et al., Chem. Eur. J. 2001, 7, 503 [V9]Tsujioka et al., J. Electrochem. Soc., 2004, 151, A1418

[0116] The six different first conductive salts according to formula (I) are hereinafter referred to as compounds 1, 2, 3, 4, 5 and 6. The compounds are a family of polyfluoroalkoxyaluminates, which can be synthesized by the reaction of LiAlH4 with the corresponding alcohol R-OH(R 1 =R 2 =R3 =R 4 ) and prepared according to the following reaction scheme:

[0117] [ka]

[0118] The chelate complexes were prepared starting from the corresponding diols H-R-OH according to the preparation method described in the literature [V10]: [V10] Wu Hsieh et al., Electrochemical and Solid State Letters, 2000, 3, 366-368

[0119] This formed compounds 1, 2, 3, 4, 5 and 6, having the molecular or structural formulas shown below:

[0120] [ka]

[0121] For purification, the compounds 1, 2, 3, 4, 5 and 6 were first recrystallized to remove any residual educt LiAlH4 from the first conductive salt, which may spark with traces of water that may be present in SO2.

[0122] Then, the compounds 1, 2, 3, 4, 5 and 6 were dissolved in SO2. It was found that compounds 1, 2, 3, 4, 5 and 6 have good solubility in SO2.

[0123] The electrolytes 1, 2, 3, 4, 5 and 6 are prepared according to the following methods: Steps 1 to 4 were followed at low temperature or under pressure: 1) Each of compounds 1, 2, 3, 4, 5 and 6 is placed in a pressure flask equipped with a riser pipe. 2) Emptying the pressure flask; 3) Liquid SO2 is injected, and 4) Repeat steps 2 and 3 until the target amount of SO2 has been added.

[0124] The concentrations of the compounds 1, 2, 3, 4, 5 and 6 in the electrolytes 1, 2, 3, 4, 5 and 6 were 0.6 mol / l (substance amount concentration per 1 liter of electrolyte) unless otherwise specified in the following experimental description. The experiments described below were carried out using the electrolytes 1, 2, 3, 4, 5 and 6 and the reference electrolyte.

[0125] Example 3: Preparation of a complete experimental cell The experimental complete cells used in the experiments described below are rechargeable battery cells with two negative electrodes and one positive electrode, each separated by a separator. The positive electrodes had active materials, a conductivity enhancer and a binder. The active materials are stated in the respective experiments. The negative electrodes also contained graphite as active material, a binder and a conductor element. If stated in the experiments, the negative electrodes may further have a conductive additive. The materials of the conductor elements of the positive and negative electrodes are aluminum and copper, which are stated in the respective experiments. The conductor element nickel is used as a reference material according to the prior art. In particular, the purpose of the experiments is to demonstrate the use of the conductor elements aluminum and copper in the positive and negative electrodes in a battery cell according to the invention. Table 3 shows the experiments carried out for different conductor elements.

[0126] The experimental complete cells were filled with the electrolyte required for the experiment, i.e., the reference electrolyte or electrolytes 1, 2, 3, 4, 5 and 6. Multiple identical experimental complete cells were prepared for the experiment, i.e., two to four. The results shown in the experiments are the average values ​​of the measurements obtained for each identical experimental complete cell.

[0127] [Example 4] Measurements in a complete experimental cell Surface capacity: The capacity consumed in the first cycle to form a surface layer on the negative electrode is an important criterion for the quality of the battery cell. The surface layer is formed on the negative electrode during the first charge of the experimental full cell. The surface layer formation consumes lithium ions irreversibly (surface capacity), which reduces the cyclable capacity available for the experimental full cell in subsequent cycles. The surface capacity (unit [%]) relative to the theoretical value used to form the surface layer on the negative electrode is calculated by the following formula:

[0128] Surface capacity [% of theoretical value] = (Q lad (xmAh)-Q ent (ymAh) / Q NEL

[0129] Q lad is the charge amount (unit [mAh]) specified in each experiment, Q ent Q is the charge (unit: mAh) obtained when the experimental complete cell was subsequently discharged. NEL is the theoretical capacity of the negative electrode used. For example, in the case of graphite, the theoretical capacity is calculated based on a value of 372 mAh / g.

[0130] Discharge capacity: In the measurement of an experimental complete cell, for example, the discharge capacity is determined by the number of cycles. For this purpose, the experimental complete cell is charged to a predetermined upper potential limit at a predetermined charging current. The corresponding upper potential limit is held until the charging current drops to a certain value. Then, discharging is performed at a predetermined discharging current until a predetermined discharging potential is reached. This charging method is called I / U charging. The process is repeated for the desired number of cycles.

[0131] The upper limit potential or the discharge capacity and the respective charge and discharge current are described in the experiments. The value to which the charge current should be reduced is also described in the experiments.

[0132] The term "upper potential limit" is used synonymously with the terms "charging potential", "charging voltage", "end-of-charge voltage" and "upper potential limit", which indicate the voltage / potential that a cell or battery must reach when being charged by a battery charging device.

[0133] Charging of the battery is preferably carried out at a current rate of C / 2 and at a temperature of 22°C.

[0134] The term "discharge potential" is used synonymously with the term "bottom cell voltage," which refers to the voltage / potential that a cell or battery must reach when it is discharged by a battery charging device.

[0135] Discharging of the battery is preferably carried out at a current rate of C / 2 and at a temperature of 22°C.

[0136] The discharge capacity is determined by the discharge current and the time until the criteria for terminating discharge are met. The associated figures show the average discharge capacity as a function of the cycle number. The average discharge capacity is often normalized to 100% of the starting capacity and expressed as a percentage of the nominal capacity.

[0137] The following experiments investigate the properties of conductor elements made either of nickel, copper or aluminum. According to [V3], conductor elements made of nickel are usually used in the prior art electrolyte LiAlCl4*xSO2, hereafter referred to as the reference electrolyte. Said conductor elements made of nickel are hereafter referred to as nickel conductor elements (see example 1). Experiments were therefore carried out on the one hand with said reference electrolyte LiAlCl4*xSO2 and on the other hand with various electrolytes which may also be components of a rechargeable battery cell according to the invention. The electrical conductivity of copper and aluminum, which is known from the literature, is better than that of nickel (see table 1). Therefore, conductor elements made of copper and aluminum are preferred within the scope of the present invention.

[0138] [Table 1]

[0139] [Experiment 1] Behavior of the negative nickel and copper conductor elements in an experimental complete cell with a reference electrolyte of composition LiAlCl4*4.5SO2 The negative electrodes were manufactured using graphite as the active material. The negative electrodes did not contain a binder. The conductor element of the first negative electrode consisted of copper in the form of a copper foam. The second negative electrode contained a nickel conductor element in the form of a nickel foam. Nickel is the material of the conductor element used in rechargeable battery cells according to the prior art with an electrolyte having the composition LiAlCl4*xSO2.

[0140] Two negative electrodes with copper conductor elements and a positive electrode containing lithium iron phosphate as the electrode active material were assembled to form a first experimental complete cell 1 according to Example 3. The negative electrode containing nickel conductor elements was used to form a second experimental complete cell 2 according to Example 3. Both experimental complete cells 1 and 2 were filled with the reference electrolyte according to Example 1, with the composition LiAlCl4*4.5SO2.

[0141] First, in the first cycle, the surface capacity was determined according to Example 4. Figure 6 shows the potential (in volts) of the experimental complete cells during charging of the negative electrode as a function of capacity (in %) with respect to the theoretical capacity of the negative electrode, where the solid line corresponds to the curve for experimental complete cell 1 and the dashed and dotted line corresponds to the curve for experimental complete cell 2.

[0142] The two illustrated curves show the results of multiple experiments carried out using the experimental complete cells 1 and 2 described above, respectively. First, a current of 125 mA (Q lad The experimental complete cell was then discharged at 15 mA until a potential of 2.5 volts was reached. The discharge capacity (Q ent ) was sought.

[0143] The determined surface capacity (unit: % of theoretical capacity of negative electrode) is higher than that determined for example for electrodes containing a binder, since the negative electrode does not contain a binder. For the experimental complete cell 1 with a graphite electrode with a copper foam conductive element, the surface capacity is 19.8%, and for the experimental complete cell 2 with a graphite electrode with a nickel foam conductive element, the surface capacity is 15.5%.

[0144] To determine the discharge capacity (see Example 4), both experimental complete cells 1 and 2 were charged to a maximum potential of 3.8 volts at a charge rate of C / 2, and then discharged to a discharge potential of 2.5 volts at a discharge rate of C / 2.

[0145] Figure 7 shows the average discharge capacity of the two experimental full cells 1 and 2 as a function of cycle number, where the solid line corresponds to the curve for experimental full cell 1 and the dashed line corresponds to the curve for experimental full cell 2. 190 cycles were performed. The average discharge capacity is expressed as a percentage of the nominal capacity (unit: % of nominal capacity).

[0146] The discharge capacity profiles of the two experimental complete cells 1 and 2 show a uniform decrease profile. However, the capacity decrease is significantly greater in the experimental complete cell containing a graphite electrode with a copper foam conductor element. Thus, the capacity in the experimental complete cell 1 (nickel conductor element) is still at 70% at 190 cycles, whereas the capacity in the experimental complete cell 2 (copper conductor element) is only at 64% at 190 cycles.

[0147] In the reference electrolyte, negative electrodes with nickel conductor elements show lower surface capacity and better cycling behavior than negative electrodes with copper conductor elements, which substantiates the statement in [V3] that nickel is the common conductor element in LiAlCl4*xSO2 electrolytes.

[0148] [Experiment 2] Behavior of nickel and copper conductor elements for the negative electrode in an experimental complete cell using electrolyte 1 Again, negative electrodes were prepared having graphite as the active material. The conductive element of the first negative electrode was made of copper in the form of a porous copper foam. The second negative electrode included a nickel conductive element in the form of a porous nickel foam. Two negative electrodes having copper foam as the conductive element were assembled into a first experimental complete cell along with a positive electrode comprising lithium nickel manganese cobalt oxide (NMC622) as the electrode active material according to Example 3. A second experimental complete cell was formed according to Example 3 using a negative electrode comprising nickel foam as the conductive element. Both experimental complete cells were filled with electrolyte 1 according to Example 2.

[0149] First, the surface capacitance was measured according to Example 4 in the first cycle.

[0150] FIG. 8 shows the potential (in volts) of both experimental complete cells during charging of the negative electrode as a function of capacity (in %) relative to the theoretical capacity of the negative electrode. The two plotted curves show the average results of several experiments each performed with the experimental complete cells described above, the solid curve corresponding to the experimental complete cell with a graphite electrode with copper conductor elements, and the dashed and dotted curve corresponding to the experimental complete cell with a graphite electrode with nickel conductor elements. First, a current of 125 mA (Q lad The experimental complete cell was then discharged at 15 mA until a potential of 2.5 volts was reached. The discharge capacity (Q ent ) was sought.

[0151] For the experimental complete cell with graphite electrodes with copper conductor elements, the surface capacitance is 6.7% and for the experimental complete cell with graphite electrodes with nickel conductor elements, the surface capacitance is 7.3%. The surface capacitance is smaller with copper conductor elements than with nickel conductor elements.

[0152] To determine the discharge capacity (see Example 4), both experimental complete cells were charged to a maximum potential of 4.4 volts at a charge rate of C / 2, and then discharged to a discharge potential of 2.5 volts at a discharge rate of C / 2.

[0153] FIG. 9 shows the average values ​​of the discharge capacities of the two experimental complete cells as a function of the number of cycles, the solid curve corresponding to the experimental complete cell with graphite electrodes with copper conductor elements and the dashed and dotted curve corresponding to the experimental complete cell with graphite electrodes with nickel conductor elements. The average values ​​of the discharge capacities are expressed as a percentage of the nominal capacity (units [% of nominal capacity]). The course of the discharge capacities of the two experimental complete cells shows a uniform, almost linear course. Only a slight capacity loss is observed in both experimental complete cells. Thus, the capacity of both experimental complete cells is still about 95% (nickel conductor elements) or 94% (copper conductor elements) at 200 cycles.

[0154] Figure 10 is a photograph showing the copper conductor element after the aforementioned measurements of Figure 9. It can be seen from Figure 10 that no corrosion of the copper conductor element occurs during the experiment.

[0155] The negative electrodes with nickel conductor elements and those with copper conductor elements show low surface capacitance and good cycling behavior in the electrolyte 1. After the experiment, no negative electrodes are observed in the copper conductor elements.

[0156] [Experiment 3] Behavior of negative copper conductor elements in half cells with electrolytes 5 and 6 Again, a negative electrode was prepared having graphite as the active material, the conductive element of said electrode being made of copper in the form of copper foil.

[0157] The experiments were carried out in half-cells with metallic lithium as return and reference electrodes. The working electrode was a graphite electrode with the copper conductor element under investigation. The half-cells were filled with electrolyte 5 on one side and electrolyte 6 on the other side. The half-cells were charged to a potential of 0.03 volts and discharged to a potential of 0.5 volts at a charge-discharge rate of 0.02C. Figure 11 illustrates the potentials of the charge and discharge curves of the half-cells in the fourth cycle in electrolyte 5 and in the second cycle in electrolyte 6, where the solid curve corresponds to the potential of the charge curve and the dashed-dotted curve corresponds to the potential of the discharge curve. The charge-discharge curves show a stable, battery-typical behavior. The copper conductor element is suitable as the negative conductor element in the electrolytes 5 and 6 and shows a stable behavior.

[0158] [Experiment 4] Behavior of conductor elements made of aluminum in half-cell experiments using a reference electrolyte and electrolyte 1 according to the invention The aim of the experiment was to investigate the long-term stability of an aluminum conductor element under current load in a reference electrolyte and in electrolyte 1. The experiment was carried out in a half-cell with metallic lithium as return and reference electrodes. The working electrodes were the aluminum conductor element in the form of an aluminum sheet under investigation, respectively. The half-cell was filled on the one hand with a reference electrolyte having the composition LiAlCl4*1.5SO2 and on the other hand with electrolyte 1.

[0159] A constant current of 0.1 mA was applied to the half-cell with the aluminum conductor element in the reference electrolyte for about 300 hours. The dashed and dotted lines in FIG. 12 show the current according to the scale on the right side of the corresponding figure and the corresponding potential (left side scale) over 90 hours. A potential of about 3.9 volts was observed over the entire time. After the experiment, the aluminum conductor element was removed from the half-cell and examined.

[0160] A constant current of 0.1 mA was also initially applied to the half-cell with the aluminum conductor element in electrolyte 1. The experimental target potential of 5.0 V was already reached after about 2 min. The current was then lowered to 0.5 μA and increased successively to 1 μA, 2 μA, 3 μA, 4 μA, 6 μA, 8 μA, 10 μA and 12 μA over a period of 10 h. The solid lines in FIG. 12 show the current according to the scale on the right side of the corresponding figure and the matching potential (left scale) over a period of 90 h. After the experiment, the aluminum conductor element was again removed from the half-cell and examined.

[0161] Figure 13 shows an example of an aluminum conductor element inserted in the respective half-cell at the beginning of the measurement. In figure 14 the aluminum conductor element can be seen after the experiment in the half-cell with the reference electrolyte. Noticeable corrosion can be seen at the edges and surfaces of the aluminum sheet after the experiment in the half-cell with the reference electrolyte. The corrosion is also reflected in the very high weight loss of the aluminum conductor element, which is 61.5%. Aluminum is not stable in the reference electrolyte under current load. In figure 15 the aluminum conductor element can be seen after the experiment in the half-cell with electrolyte 1. No changes can be seen in the aluminum sheet compared to the beginning of the measurement, i.e. no corrosion is observed in the conductor element. Aluminum is very stable in electrolyte 1 according to the invention under current load.

[0162] [Experiment 5] Behavior of aluminum conductor elements of positive electrodes in experimental complete and half cells with electrolyte 1 To further investigate the conductor element made of aluminum, the conductor element was coated with the positive electrode active material. 0.5 Mn 1.5A positive electrode was prepared with O4 (LNMO). LNMO is an active material that can be charged to a high upper potential limit, e.g., 5 volts. The conductor element of the electrode consisted of aluminum in the form of an aluminum sheet. The positive electrode was used to form a half-cell with a lithium electrode as the return electrode and reference electrode. The half-cell was filled with electrolyte 1. To determine the discharge capacity (see Example 4), the half-cell was charged and discharged to a potential of 5 volts at a charge / discharge rate of 0.1C.

[0163] FIG. 16 illustrates the potential as a function of capacity for the first cycle charge curve (solid line) and discharge curve (dashed dot line) of a half-cell with an aluminum conductor element.

[0164] The charge / discharge curves show a stable, battery-typical behavior: the aluminum conductor element is extremely stable as a positive conductor element in the electrolyte 1.

[0165] [Experiment 6] Behavior of the aluminum conductor element of the positive electrode in an experimental complete cell with electrolyte 1 To further investigate the stability of the aluminum conductor element, an experimental complete cell was assembled using a positive electrode containing nickel manganese cobalt oxide (NMC622) as active material and aluminum foil as conductor element, and two negative electrodes. The negative electrode contained graphite as active material and nickel conductor element. To determine the discharge capacity (see Example 4), the experimental complete cell was charged to a maximum potential of 4.4 volts at a charge rate of 0.1 C. It was then discharged to a discharge potential of 2.8 volts at a discharge rate of 0.1 C. Figure 17 illustrates the course of discharge capacity over 200 cycles. The experimental complete cell shows a very stable behavior with a nearly flat capacity course. This demonstrates that the aluminum conductor element as the conductor element in the positive electrode is very stable in electrolyte 1.

[0166] [Experiment 7] Behavior of the positive aluminum conductor element in combination with the negative copper conductor element in a complete cell using electrolyte 1 To investigate the behavior of the aluminum conductor element of the positive electrode in combination with the copper conductor element of the negative electrode in a complete cell with electrolyte 1 according to the invention, 24 negative electrodes and 23 positive electrodes were used to form a complete cell. The positive electrode contained nickel manganese cobalt oxide (NMC622) as active material and aluminum foil as conductor element. The negative electrode contained graphite as active material and copper foil as conductor element. To determine the discharge capacity (see Example 4), the complete cells were charged to various upper potential limits of 4.3 or 4.6 volts at a charge rate of 0.1 C. The charge capacity was limited to 50% of the theoretical cell capacity. Discharge was then performed to a discharge potential of 2.8 volts at a discharge rate of 0.1 C. FIG. 18 illustrates the course of the discharge capacity over 10 cycles, normalized to the maximum capacity of the complete cell with an upper potential limit of 4.3 V and the complete cell with an upper potential limit of 4.6 V. The complete cell shows a very stable behavior with an almost flat capacity profile even when measured at higher upper potential limits, demonstrating that the positive aluminum conductor element in combination with the negative copper conductor element is very stable in the complete cell with electrolyte 1.

[0167] [Experiment 8] Positive aluminum conductor in a half cell with electrolyte 5 Element Behavior A positive electrode was prepared using nickel manganese cobalt oxide (NMC811) as the active material. The conductor element of the positive electrode consisted of aluminum in the form of aluminum foil. The experiment was carried out in a half-cell with metallic lithium as the return and reference electrodes. The working electrode was the positive electrode with the aluminum conductor element under investigation.

[0168] The half-cell was filled with electrolyte 5. To determine the discharge capacity (see Example 4), the half-cell was charged to a potential of 3.9 volts and discharged to a potential of 3 volts at a charge / discharge rate of 0.02C.

[0169] FIG. 19 illustrates the second cycle potential as a function of capacity for a half-cell having an aluminum conductor element upon charging.

[0170] The charge / discharge curves show a stable, battery-typical behavior: the aluminum conductor element is very stable as a positive conductor element in the electrolyte 5.

[0171] [Experiment 8] Investigation of electrolytes 1, 3, 4 and 5 Various experiments were carried out to investigate electrolytes 1, 3, 4 and 5. On the one hand, the surface capacitances of electrolytes 1 and 3 and a reference electrolyte were determined and on the other hand the discharge capacities in electrolytes 1, 3, 4 and 5 were measured.

[0172] To determine the surface capacity, three experimental complete cells were filled with electrolytes 1 and 3 described in Example 2 and the reference electrolyte described in Example 1. The three experimental complete cells contained lithium iron phosphate as the positive active material.

[0173] FIG. 20 illustrates the potential (in volts) of an experimental complete cell during charging of the negative electrode as a function of capacity relative to the theoretical capacity of the negative electrode. The two illustrated curves show the results of several experiments each performed using the experimental complete cell. First, a current of 125 mA (Q lad The experimental complete cell was then discharged at 15 mA until a potential of 2.5 volts was reached. The discharge capacity (Q ent ) was sought.

[0174] The absolute capacity loss is 7.58% or 11.51% for the electrolytes 1 and 3, respectively, and 6.85% for the reference electrolyte. The capacity for surface layer formation is slightly higher for both electrolytes according to the invention than for the reference electrolyte. The absolute capacity loss values ​​in the range of 7.5% to 11.5% are good results in combination with the possibility of using high voltage cathodes up to 5 volts. For discharge experiments, four experimental complete cells according to example 3 were filled with electrolytes 1, 3, 4 and 5 described in example 2. The experimental complete cells contained lithium nickel manganese cobalt oxide (NMC) as the active material of the positive electrode. To determine the discharge capacity (see example 4), the experimental complete cells were charged to a capacity of 125 mAh using a current of 15 mA. Then, a discharge was performed to a discharge potential of 2.5 volts using a current of 15 mA.

[0175] Figure 21 shows the percentage of potential evolution during discharge over the discharged charge (unit: [% of maximum charge (discharge)]). All experimental full cells show flat discharge curves, which is necessary for good operation of the battery cell.

[0176] [Experiment 9] Measurement of the conductivity of electrolytes 1, 3, 4, 5 and 6 For conductivity measurements, electrolytes 1, 3, 4, 5 and 6 were prepared with different concentrations of compounds 1, 3, 4, 5 and 6. For each of the different compound concentrations, the conductivity of the electrolyte was measured using a conductance measurement method, in which a four-electrode sensor was held in contact with the solution after tempering, and the measurement range was 0.02 to 500 mS / cm.

[0177] FIG. 22 illustrates the conductivity of electrolytes 1, 4 and 6 depending on the concentration of compounds 1, 4 and 6. A maximum conductivity of about 37.9 mS / cm is found for electrolyte 1 when the concentration of compound 1 is between 0.6 mol / L and 0.7 mol / L. In comparison, organic electrolytes known from the prior art, such as LP30 (1M LiPF6 / EC-DMC (1:1 by weight), only have a conductivity of about 10 mS / cm. For electrolyte 4, a maximum of 18 mS / cm is obtained for a conductive salt concentration of 1 mol / L. For electrolyte 6, a maximum of 11 mS / cm is shown for a conductive salt concentration of 0.6 mol / L.

[0178] FIG. 23 illustrates the conductivity of electrolytes 3 and 5 depending on the concentration of compounds 3 and 5. For electrolyte 5, a maximum of 1.3 mS / cm is obtained when the conductive salt concentration is 0.8 mol / L. Electrolyte 3 shows a maximum conductivity of 0.5 mS / cm when the conductive salt concentration is 0.6 mol / L. Although the conductivity of electrolytes 3 and 5 was low, it is sufficient to charge or discharge, for example, the experimental half cell described in experiment 3 or the experimental full cell described in experiment 8.

[0179] [Experiment 10] Low-temperature behavior Two experimental complete cells were prepared according to Example 3 to measure the low-temperature behavior of the electrolyte 1 in comparison with the reference electrolyte. One experimental complete cell was filled with the reference electrolyte having the composition LiAlCl4*6SO2, and the other experimental complete cell was filled with electrolyte 1. The experimental complete cell containing the reference electrolyte contained lithium iron phosphate (LEP) as the positive active material, and the experimental cell containing electrolyte 1 contained lithium nickel manganese cobalt oxide (NMC) as the active material. The experimental complete cells were charged to 3.6 volts (LEP) or 4.4 volts (NMC) at 20°C and discharged again to 2.5 volts at each investigated temperature. The discharge capacity reached at 20°C was evaluated as 100%. The temperature for discharge was reduced in temperature steps of 10°K. The obtained discharge capacity was expressed as a percentage of the discharge capacity at 20°C. The low-temperature discharge is largely independent of the positive and negative active materials used, so the results are applicable to all active material combinations. Table 5 shows the results.

[0180] The experimental full cell with electrolyte 1 shows very good low-temperature behavior. At 20° C. it still reaches 82% of the capacity, at −30° C. it still reaches 73%. Even at a temperature of −40° C. it is still possible to discharge 61% of the capacity. In contrast, the experimental full cell with the reference electrolyte can only be discharged down to −10° C. In this case it reaches 21% of the capacity. At lower temperatures it is no longer possible to discharge the cell with the reference electrolyte.

[0181] [Table 5]

Claims

1. A rechargeable battery cell (2, 20, 40) comprising at least one positive electrode (4, 23, 44) having an active metal, an active material and a conductor element (26), at least one negative electrode (5, 22, 45) having a conductor element (27), a housing (1, 28) and an electrolyte, The conductor element (26) of the positive electrode (4, 23, 44) and the conductor element (27) of the negative electrode (5, 22, 45) are formed of materials selected independently of each other from the group formed by aluminum and copper, and further, the electrolyte is an SO ２ system and has the formula (I) 【Chemical 1】 comprising at least one first conductive salt, - M is a metal selected from the group formed by alkali metals, alkaline earth metals, metals of Group 12 of the periodic table and aluminum, - x is an integer from 1 to 3, - Substituent R １ , R ２ , R ３ and R ４ are each independently selected from the group formed by C １ to C ４ alkyl, and further - the substituent R １ , R ２ , R ３ and R ４ at least one of each of the hydrogen atoms is substituted by at least one fluorine atom, and in the substituents R1, R2, R3 and R4, there are more fluorine atoms than hydrogen atoms, - Optionally, said substituent R １ , R ２ , R ３ and R ４ , at least one of each of the hydrogen atoms is substituted by at least one chemical group, and said chemical group is selected from the group formed by C １ to C ４ alkyl, where the fluorine atoms of said C1-C4 alkyl are more than the hydrogen atoms, - Optionally, the substituent R １ , R ２ , R ３ and R ４ at least two of which are cross-linked to each other to form a chelate ligand, - Z is aluminum or boron, characterized rechargeable battery cell (2, 20, 40).

2. The conductor element (26) of the positive electrode (4, 23, 44) is formed of aluminum, characterized in that the rechargeable battery cell (2, 20, 40) according to claim 1.

3. The conductor element (27) of the negative electrode (5, 22, 45) is formed of copper, characterized in that the rechargeable battery cell (2, 20, 40) according to claim 1 or 2.

4. The conductor element (26) of the positive electrode (4, 23, 44) and / or the conductor element (27) of the negative electrode (5, 22, 45) is - in a planar shape in the form of a thin metal sheet, a thin metal foil, or a plastic foil coated with a metal, or - in the shape of a three-dimensional porous metal structure formed, characterized in that the rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 3.

5. Having a cell voltage of at least 4.0 volts, characterized in that the rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 4.

6. The substituent R of the first conductive salt １ , R ２ , R ３ and R ４ in which at least one of them is a CF ３ group, and the rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 5.

7. The first conductive salt is selected from the group formed by the following, characterized in that the rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 6: [Chemical Formula 2] and 【Chemical Formula 3】 。

8. The electrolyte comprises at least one second conductive salt different from the first conductive salt according to formula (I), characterized in that the rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 7.

9. The second conductive salt of the electrolyte is an alkali metal compound, and the alkali metal compound is selected from the group formed by aluminates, halides, oxalates, borates, phosphates, arsenates, and gallates. The rechargeable battery cell (2, 20, 40) according to claim 8.

10. The electrolyte includes at least one additive. The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 9.

11. The additive of the electrolyte is vinylene carbonate and its derivatives, vinyl ethylene carbonate and its derivatives, methyl ethylene carbonate and its derivatives, lithium (bisoxalato) borate, lithium difluoro(oxalato) borate, lithium tetrafluoro(oxalato) phosphate, lithium oxalate, 2-vinyl pyridine, 4-vinyl pyridine, cyclic exomethylene carbonate, sulfone, cyclic and acyclic sulfonates, acyclic sulfites, cyclic and acyclic sulfinates, organic esters, inorganic acids, acyclic and cyclic alkanes (the acyclic and cyclic alkanes have a boiling point of at least 36 °C at 1 bar), aromatic compounds, halogenated cyclic and acyclic sulfonylimides, halogenated cyclic and acyclic phosphate esters, halogenated cyclic and acyclic phosphines, halogenated cyclic and acyclic phosphites, halogenated cyclic and acyclic phosphazenes, halogenated cyclic and acyclic silylamines, halogenated cyclic and acyclic halogenated esters, halogenated cyclic and acyclic amides, halogenated cyclic and acyclic anhydrides, and halogenated organic heterocycles. The rechargeable battery cell (2, 20, 40) according to claim 10.

12. The electrolyte has the following composition with respect to the total weight of the electrolyte composition. The rechargeable battery cell (2, 20, 40) according to claim 10 or 11 that directly or indirectly quotes claim 8 or 9: (i) 5 to 99.4 wt% sulfur dioxide, (ii) 0.6 to 95 wt% of the first conductive salt, (iii) 0 to 25 wt% of the second conductive salt, and (iv) 0 to 10 wt% of the additive.

13. The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 12, characterized in that the molar concentration of the first conductive salt is in the range of 0.01 mol / l to 10 mol / l with respect to the total volume of the electrolyte.

14. The electrolyte contains at least 0.1 mol of SO per mol of conductive salt ２ The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 13, characterized in that it contains the same.

15. The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 14, characterized in that the active metal is one of the following: - An alkali metal, - An alkaline earth metal, - A metal of Group 12 of the periodic table, or - Aluminum.

16. The positive electrode (4, 23, 44) contains at least one compound having a composition of A ｘ M’ ｙ M” ｚ O ａ and includes - A is at least one metal selected from the group formed by an alkali metal, an alkaline earth metal, a metal of Group 12 of the periodic table or aluminum, - M' is at least one metal selected from the group formed by the elements Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn, - M" is at least one element selected from the group formed by the elements of Groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table, - x and y are each independently a number greater than 0, - z is a number greater than or equal to 0, and further - a is a number greater than 0 The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 15, characterized in that.

17. The compound is Li ｘ Ni ｙ１ Mn ｙ２ Co ｚ O ａ having a composition of, where x, y1, and y2 are each independently a number greater than 0, z is a number greater than or equal to 0, and further a is a number greater than 0, the rechargeable battery cell (2, 20, 40) according to claim 16.

18. The compound has the composition of A ｘ M’ ｙ M” １ ｚ１ M” ２ ｚ２ O ４ and has the following composition -M" １ is selected from the group consisting of elements of Groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the Periodic Table of the Elements, -M" ２ is elemental phosphorus, - x and y are each independently a number greater than 0, - z1 is a number greater than 0, and further - The value of z2 is 1 The rechargeable battery cell (2, 20, 40) according to claim 16, characterized in that.

19. The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 18, characterized in that the positive electrode (4, 23, 44) contains at least one metal compound, and the metal compound is selected from the group formed by metal oxides, metal halides and metal phosphates.

20. The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 19, characterized in that the positive electrode (4, 23, 44) contains at least one metal compound having a chemical structure of a spinel, a layered oxide, a conversion compound or a polyanion compound.

21. The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 20, characterized in that the negative electrode (5, 22, 45) is an insertion electrode.

22. The positive electrode (4, 23, 44) and / or the negative electrode (5, 22, 45) includes at least one fluorinated binder, or a binder made of a polymer composed of a monomer structural unit of a conjugated carboxylic acid or an alkali metal salt, alkaline earth metal salt, or ammonium salt of the conjugated carboxylic acid, or a combination thereof, or a binder made of a monomer styrene and butadiene structural unit-based polymer or a binder made of a carboxymethyl cellulose group, The binder is present at a concentration of at most 20 wt% with respect to the total weight of the positive electrode or the negative electrode. The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 21. **Claim 23** Comprising a plurality of negative electrodes (5, 22, 45) and at least one positive electrode (4, 23, 44) which are alternately laminated and arranged in the housing (1, 28), and the positive electrode (4, 23, 44) and the negative electrode (5, 22, 45) are electrically separated from each other by separators (11, 21, 13) respectively. The rechargeable battery cell (2, 20, 40) according to any one of claims 1 to 22.

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